Discrimination of surface wear on obsidian tools using LSCM and RelA: pilot study results (area-scale analysis of obsidian tool surfaces).

PubMed

Stemp, W James; Chung, Steven

2011-01-01

This pilot study tests the reliability of laser scanning confocal microscopy (LSCM) to quantitatively measure wear on experimental obsidian tools. To our knowledge, this is the first use of confocal microscopy to study wear on stone flakes made from an amorphous silicate like obsidian. Three-dimensional surface roughness or texture area scans on three obsidian flakes used on different contact materials (hide, shell, wood) were documented using the LSCM to determine whether the worn surfaces could be discriminated using area-scale analysis, specifically relative area (RelA). When coupled with the F-test, this scale-sensitive fractal analysis could not only discriminate the used from unused surfaces on individual tools, but was also capable of discriminating the wear histories of tools used on different contact materials. Results indicate that such discriminations occur at different scales. Confidence levels for the discriminations at different scales were established using the F-test (mean square ratios or MSRs). In instances where discrimination of surface roughness or texture was not possible above the established confidence level based on MSRs, photomicrographs and RelA assisted in hypothesizing why this was so. Copyright © 2011 Wiley Periodicals, Inc.

Relationships among particle number, surface area, and respirable mass concentrations in automotive engine manufacturing.

PubMed

Heitbrink, William A; Evans, Douglas E; Ku, Bon Ki; Maynard, Andrew D; Slavin, Thomas J; Peters, Thomas M

2009-01-01

This study investigated the relationships between particle number, surface area, and respirable mass concentration measured simultaneously in a foundry and an automotive engine machining and assembly center. Aerosol concentrations were measured throughout each plant with a condensation particle counter for number concentration, a diffusion charger for active surface area concentration, and an optical particle counter for respirable mass concentration. At selected locations, particle size distributions were characterized with the optical particle counter and an electrical low pressure impactor. Statistical analyses showed that active surface area concentration was correlated with ultrafine particle number concentration and weakly correlated with respirable mass concentration. Correlation between number and active surface area concentration was stronger during winter (R2 = 0.6 for both plants) than in the summer (R2 = 0.38 and 0.36 for the foundry and engine plant respectively). The stronger correlation in winter was attributed to use of direct-fire gas fired heaters that produced substantial numbers of ultrafine particles with a modal diameter between 0.007 and 0.023 mu m. These correlations support findings obtained through theoretical analysis. Such analysis predicts that active surface area increasingly underestimates geometric surface area with increasing particle size, particularly for particles larger than 100 nm. Thus, a stronger correlation between particle number concentration and active surface area concentration is expected in the presence of high concentrations of ultrafine particles. In general, active surface area concentration may be a concentration metric that is distinct from particle number concentration and respirable mass concentration. For future health effects or toxicological studies involving nano-materials or ultrafine aerosols, this finding needs to be considered, as exposure metrics may influence data interpretation.

Multivariate optimum interpolation of surface pressure and winds over oceans

NASA Technical Reports Server (NTRS)

Bloom, S. C.

1984-01-01

The observations of surface pressure are quite sparse over oceanic areas. An effort to improve the analysis of surface pressure over oceans through the development of a multivariate surface analysis scheme which makes use of surface pressure and wind data is discussed. Although the present research used ship winds, future versions of this analysis scheme could utilize winds from additional sources, such as satellite scatterometer data.

ANALYSIS OF RESPIRATORY DEPOSITION OF INHALED PARTICLES FOR DIFFERENT DOSE METRICS: COMPARISON OF NUMBER, SURFACE AREA AND MASS DOSE OF TYPICAL AMBIENT BI-MODAL AEROSOLS

EPA Science Inventory

ANALYSIS OF RESPIRATORY DEPOSITION OF INHALED PARTICLES FOR DIFFERENT DOSE METRICS: COMPARISON OF NUMBER, SURFACE AREA AND MASS DOSE OF TYPICAL AMBIENT BI-MODAL AEROSOLS.
Chong S. Kim, SC. Hu*, PA Jaques*, US EPA, National Health and Environmental Effects Research Laboratory, ...

Synthesis and Characterization of Chitosan-p-t-Butylcalix[4]arene acid

NASA Astrophysics Data System (ADS)

Handayani, D. S.; Frimadasi, W.; Kusumaningsih, T.; Pranoto

2018-03-01

The synthesis of chitosan-p-t-butylcalix[4]arene acid was done with DIC (N, N’-diisopropylcarbodiimide) as the coupling agent. The structural analysis of the chitosan-p-t-butylcalix[4]arene acid was conducted by spectrophotometer Fourier Transform Infra Red (FTIR) and X-Ray Diffraction (XRD). Meanwhile, the surface area was investigated by Surface Area Analysis, the Scanning Electrone Microscope (SEM) analysed the surface morphology, and also the melting point temperature was determined. FTIR analysis on Chitosan-p-t-butylcalix[4]arene provides an overlapped absorption of -OH and -NH groups at 3438.26 cm-1. Meanwhile, a C = C aromatic bond present at 1480.43 cm-1. XRD analysis shows some broaden peaks due to the amorphous phase of the prepared material. The prepared material is a brownish yellow solid, odorless and porous. The melting point, surface area, and the average pore radius are above 300 °C, 9.42 m2 / g, and 52.5938 Å, respectively.

Phase quantification by X-ray photoemission valence band analysis applied to mixed phase TiO2 powders

NASA Astrophysics Data System (ADS)

Breeson, Andrew C.; Sankar, Gopinathan; Goh, Gregory K. L.; Palgrave, Robert G.

2017-11-01

A method of quantitative phase analysis using valence band X-ray photoelectron spectra is presented and applied to the analysis of TiO2 anatase-rutile mixtures. The valence band spectra of pure TiO2 polymorphs were measured, and these spectral shapes used to fit valence band spectra from mixed phase samples. Given the surface sensitive nature of the technique, this yields a surface phase fraction. Mixed phase samples were prepared from high and low surface area anatase and rutile powders. In the samples studied here, the surface phase fraction of anatase was found to be linearly correlated with photocatalytic activity of the mixed phase samples, even for samples with very different anatase and rutile surface areas. We apply this method to determine the surface phase fraction of P25 powder. This method may be applied to other systems where a surface phase fraction is an important characteristic.

Correlation of Superior Canal Dehiscence Surface Area With Vestibular Evoked Myogenic Potentials, Audiometric Thresholds, and Dizziness Handicap.

PubMed

Hunter, Jacob B; O'Connell, Brendan P; Wang, Jianing; Chakravorti, Srijata; Makowiec, Katie; Carlson, Matthew L; Dawant, Benoit; McCaslin, Devin L; Noble, Jack H; Wanna, George B

2016-09-01

To correlate objective measures of vestibular and audiometric function as well as subjective measures of dizziness handicap with the surface area of the superior canal dehiscence (SCD). Retrospective chart review and radiological analysis. Single tertiary academic referral center. Preoperative computed tomography imaging, patient survey, audiometric thresholds, and vestibular evoked myogenic potential (VEMP) testing in patients with confirmed SCD. Image analysis techniques were developed to measure the surface area of each SCD in computed tomography imaging. Preoperative ocular and cervical VEMPs, air and bone conduction thresholds, air-bone gap, dizziness handicap inventory scores, and surface area of the SCD. Fifty-three patients (mean age 52.7 yr) with 84 SCD were analyzed. The median surface area of dehiscence was 1.44 mm (0.068-8.23 mm). Ocular VEMP amplitudes (r = 0.61, p <0.0001), cervical VEMP amplitudes (r = 0.62, p <0.0001), air conduction thresholds at 250 Hz (r = 0.25, p = 0.043), and air-bone gap at 500 Hz (r = 0.27, p = 0.01) positively correlated with increasing size of dehiscence. An inverse relationship between cervical VEMP thresholds (r = -0.56, p < 0.0001) and surface area of the dehiscence was observed. No association between dizziness handicap and surface area was identified. Among patients with confirmed SCD, ocular and cervical VEMP amplitudes, cervical VEMP thresholds, and air conduction thresholds at 250 Hz are significantly correlated with the surface area of the dehiscence.

Application of spatially gridded temperature and land cover data sets for urban heat island analysis

USGS Publications Warehouse

Gallo, Kevin; Xian, George Z.

2014-01-01

Two gridded data sets that included (1) daily mean temperatures from 2006 through 2011 and (2) satellite-derived impervious surface area, were combined for a spatial analysis of the urban heat-island effect within the Dallas-Ft. Worth Texas region. The primary advantage of using these combined datasets included the capability to designate each 1 × 1 km grid cell of available temperature data as urban or rural based on the level of impervious surface area within the grid cell. Generally, the observed differences in urban and rural temperature increased as the impervious surface area thresholds used to define an urban grid cell were increased. This result, however, was also dependent on the size of the sample area included in the analysis. As the spatial extent of the sample area increased and included a greater number of rural defined grid cells, the observed urban and rural differences in temperature also increased. A cursory comparison of the spatially gridded temperature observations with observations from climate stations suggest that the number and location of stations included in an urban heat island analysis requires consideration to assure representative samples of each (urban and rural) environment are included in the analysis.

Changes in surface area of the Böön Tsagaan and Orog lakes (Mongolia, Valley of the Lakes, 1974-2013) compared to climate and permafrost changes

NASA Astrophysics Data System (ADS)

Szumińska, Danuta

2016-07-01

The main aim of the study is the analysis of changes in surface area of lake Böön Tsagaan (45°35‧N, 99°8‧E) and lake Orog (45°3‧N, 100°44‧E) taking place in the last 40 years in the context of climate conditions and permafrost degradation. The lakes, located in Central Mongolia, at the borderline of permafrost range are fed predominantly by river waters and groundwater from the surrounding mountain areas, characterized by continuous and discontinuous permafrost occurrence - mostly the Khangai. The analysis of the Böön Tsagaan and Orog lake surface area in 1974-2013 was conducted based on satellite images, whereas climate conditions were analysed using the NOAA climate data and CRU dataset. Principal Component Analysis (PCA) was used to study the relationship patterns between the climatic factors and changes in the surface area of the lakes. A tendency for a decrease in surface area, intermittent with short episodes of resupply, was observed in both studied lakes. Climate changes recorded in the analysed period had both direct and indirect impacts on water supply to lakes. Taking into account the results of PCA analysis, the most significant factors include: fluctuation of annual precipitation, increase in air temperature and thickness of snow cover. The extended duration of snow cover in the last decades of the 20th century may constitute a key factor in relation to permafrost degradation.

Evaluation of accessible mineral surface areas for improved prediction of mineral reaction rates in porous media

NASA Astrophysics Data System (ADS)

Beckingham, Lauren E.; Steefel, Carl I.; Swift, Alexander M.; Voltolini, Marco; Yang, Li; Anovitz, Lawrence M.; Sheets, Julia M.; Cole, David R.; Kneafsey, Timothy J.; Mitnick, Elizabeth H.; Zhang, Shuo; Landrot, Gautier; Ajo-Franklin, Jonathan B.; DePaolo, Donald J.; Mito, Saeko; Xue, Ziqiu

2017-05-01

The rates of mineral dissolution reactions in porous media are difficult to predict, in part because of a lack of understanding of mineral reactive surface area in natural porous media. Common estimates of mineral reactive surface area used in reactive transport models for porous media are typically ad hoc and often based on average grain size, increased to account for surface roughness or decreased by several orders of magnitude to account for reduced surface reactivity of field as opposed to laboratory samples. In this study, accessible mineral surface areas are determined for a sample from the reservoir formation at the Nagaoka pilot CO2 injection site (Japan) using a multi-scale image analysis based on synchrotron X-ray microCT, SEM QEMSCAN, XRD, SANS, and FIB-SEM. This analysis not only accounts for accessibility of mineral surfaces to macro-pores, but also accessibility through connected micro-pores in smectite, the most abundant clay mineral in this sample. While the imaging analysis reveals that most of the micro- and macro-pores are well connected, some pore regions are unconnected and thus inaccessible to fluid flow and diffusion. To evaluate whether mineral accessible surface area accurately reflects reactive surface area a flow-through core experiment is performed and modeled at the continuum scale. The core experiment is performed under conditions replicating the pilot site and the evolution of effluent solutes in the aqueous phase is tracked. Various reactive surface area models are evaluated for their ability to capture the observed effluent chemistry, beginning with parameter values determined as a best fit to a disaggregated sediment experiment (Beckingham et al., 2016) described previously. Simulations that assume that all mineral surfaces are accessible (as in the disaggregated sediment experiment) over-predict the observed mineral reaction rates, suggesting that a reduction of RSA by a factor of 10-20 is required to match the core flood experimental data. While the fit of the effluent chemistry (and inferred mineral dissolution rates) greatly improve when the pore-accessible mineral surface areas are used, it was also necessary to include highly reactive glass phases to match the experimental observations, in agreement with conclusions from the disaggregated sediment experiment. It is hypothesized here that the 10-20 reduction in reactive surface areas based on the limited pore accessibility of reactive phases in core flood experiment may be reasonable for poorly sorted and cemented sediments like those at the Nagaoka site, although this reflects pore rather than larger scale heterogeneity.

The impact of surface area, volume, curvature, and Lennard-Jones potential to solvation modeling.

PubMed

Nguyen, Duc D; Wei, Guo-Wei

2017-01-05

This article explores the impact of surface area, volume, curvature, and Lennard-Jones (LJ) potential on solvation free energy predictions. Rigidity surfaces are utilized to generate robust analytical expressions for maximum, minimum, mean, and Gaussian curvatures of solvent-solute interfaces, and define a generalized Poisson-Boltzmann (GPB) equation with a smooth dielectric profile. Extensive correlation analysis is performed to examine the linear dependence of surface area, surface enclosed volume, maximum curvature, minimum curvature, mean curvature, and Gaussian curvature for solvation modeling. It is found that surface area and surfaces enclosed volumes are highly correlated to each other's, and poorly correlated to various curvatures for six test sets of molecules. Different curvatures are weakly correlated to each other for six test sets of molecules, but are strongly correlated to each other within each test set of molecules. Based on correlation analysis, we construct twenty six nontrivial nonpolar solvation models. Our numerical results reveal that the LJ potential plays a vital role in nonpolar solvation modeling, especially for molecules involving strong van der Waals interactions. It is found that curvatures are at least as important as surface area or surface enclosed volume in nonpolar solvation modeling. In conjugation with the GPB model, various curvature-based nonpolar solvation models are shown to offer some of the best solvation free energy predictions for a wide range of test sets. For example, root mean square errors from a model constituting surface area, volume, mean curvature, and LJ potential are less than 0.42 kcal/mol for all test sets. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Quantitative Detection of Prostatic-Specific Antigens by Using Scanning Electron Microscopy for the Analysis of Protein Chips.

PubMed

Lee, Jisu; Jung, Moon Youn; Park, Hyung Ju

2017-04-01

We reported that quantitative detection of prostatic-specific antigen (PSA), which is the biomarker of prostate cancer, could be carried out by calculating the number density and the area ratio of gold nanoparticle probes on the surface of silicon oxide chips. When chips selectively activated with PSA were immersed in the gold nanoparticles conjugated with prostatic specific antigens-poly clonal antibodies (PSA-pAb), it was possible to observe changes in the number density and the area ratio of gold nanoparticles on the surface of the chips according to the concentration of PSA with scanning electron microscopy (SEM) images. As PSA concentration increased, the number density and the area ratio of gold nanoparticle probes on the surfaces of the chips increased accordingly. Conversely, with lower concentration, the number density and the area ratio of gold nanoparticle probes on the surfaces decreased at a certain ratio. We observed the correlations between PSA concentration and number density, area ratio of gold nanoparticle probes through the analysis of SEM images. In addition, it was confirmed that the sizes of the gold nanoparticles affected the detection limit of the number density and the area ratio of gold nanoparticle probes on the surface.

Finite element analysis (FEA) of dental implant fixture for mechanical stability and rapid osseointegration

NASA Astrophysics Data System (ADS)

Tabassum, Shafia; Murtaza, Ahmar; Ali, Hasan; Uddin, Zia Mohy; Zehra, Syedah Sadaf

2017-10-01

For rapid osseointegration of dental implant fixtures, various surface treatments including plasma spraying, hydroxyapatite coating, acid-etching, and surface grooving are used. However undesirable effects such as chemical modifications, loss of mechanical properties, prolonged processing times and post production treatment steps are often associated with these techniques. The osseointegration rate of the dental implants can be promoted by increasing the surface area of the dental implant, thus increasing the bone cells - implant material contact and allow bone tissues to grow rapidly. Additive Manufacturing (AM) techniques can be used to fabricate dental implant fixtures with desirable surface area in a single step manufacturing process. AM allows the use of Computer Aided Designing (CAD) for customised rapid prototyping of components with precise control over geometry. In this study, the dental implant fixture that replaces the tooth root was designed on commercially available software COMSOL. Nickel - titanium alloy was selected as build materials for dental implant. The geometry of the dental fixture was varied by changing the interspacing distance (thread pitch) and number of threads to increase the total surface area. Three different microstructures were introduced on the surface of dental implant. The designed models were used to examine the effect of changing geometries on the total surface area. Finite Element Analysis (FEA) was performed to investigate the effect of changing geometries on the mechanical properties of the dental implant fixtures using stress analysis.

Sea surface temperature of the coastal zones of France. Heat Capacity Mapping Mission (HCMM)

NASA Technical Reports Server (NTRS)

Deschamps, P. Y.; Frouin, R.; Cassanet, G.; Verger, F. (Principal Investigator)

1979-01-01

The author has identified the following significant results. HCMM data analysis shows some mesoscale features which were previously expected to occur: summer coastal upwellings in the Gulf of Lions, tidal fronts bordering the English Channel, and cooler surface waters at the continental shelf break. The analysis of the spectral variance density spectra show that the interpretation of the data usually is limited by the HCMM radiometric performance (noise levels) at wavenumbers below 5 km in the oceanic areas; from this analysis it may also be concluded that a decrease of the radiometric noise level down to 0.1 k against an increase of the ground resolution up to 2 km would give a better optimum of the radiometric performances in the oceanic areas. HCMM data appear to be useful for analysis of the sea surface temperature field, particularly in the very coastal area by profiting from the ground resolution of 500 m.

Data Point Averaging for Computational Fluid Dynamics Data

NASA Technical Reports Server (NTRS)

Norman, Jr., David (Inventor)

2016-01-01

A system and method for generating fluid flow parameter data for use in aerodynamic heating analysis. Computational fluid dynamics data is generated for a number of points in an area on a surface to be analyzed. Sub-areas corresponding to areas of the surface for which an aerodynamic heating analysis is to be performed are identified. A computer system automatically determines a sub-set of the number of points corresponding to each of the number of sub-areas and determines a value for each of the number of sub-areas using the data for the sub-set of points corresponding to each of the number of sub-areas. The value is determined as an average of the data for the sub-set of points corresponding to each of the number of sub-areas. The resulting parameter values then may be used to perform an aerodynamic heating analysis.

Data Point Averaging for Computational Fluid Dynamics Data

NASA Technical Reports Server (NTRS)

Norman, David, Jr. (Inventor)

2014-01-01

A system and method for generating fluid flow parameter data for use in aerodynamic heating analysis. Computational fluid dynamics data is generated for a number of points in an area on a surface to be analyzed. Sub-areas corresponding to areas of the surface for which an aerodynamic heating analysis is to be performed are identified. A computer system automatically determines a sub-set of the number of points corresponding to each of the number of sub-areas and determines a value for each of the number of sub-areas using the data for the sub-set of points corresponding to each of the number of sub-areas. The value is determined as an average of the data for the sub-set of points corresponding to each of the number of sub-areas. The resulting parameter values then may be used to perform an aerodynamic heating analysis.

The role of advanced reactive surface area characterization in improving predictions of mineral reaction rates

NASA Astrophysics Data System (ADS)

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

2014-12-01

Geologic sequestration of CO2 in deep sedimentary formations is a promising means of mitigating carbon emissions from coal-fired power plants but the long-term fate of injected CO2 is challenging to predict. Reactive transport models are used to gain insight over long times but rely on laboratory determined mineral reaction rates that have been difficult to extrapolate to field systems. This, in part, is due to a lack of understanding of mineral reactive surface area. Many models use an arbitrary approximation of reactive surface area, applying orders of magnitude scaling factors to measured BET or geometric surface areas. Recently, a few more sophisticated approaches have used 2D and 3D image analyses to determine mineral-specific reactive surface areas that account for the accessibility of minerals. However, the ability of these advanced surface area estimates to improve predictions of mineral reaction rates has yet to be determined. In this study, we fuse X-ray microCT, SEM QEMSCAN, XRD, SANS, and SEM-FIB analysis to determine mineral-specific accessible reactive surface areas for a core sample from the Nagaoka pilot CO2 injection site (Japan). This sample is primarily quartz, plagioclase, smectite, K-feldspar, and pyroxene. SEM imaging shows abundant smectite cement and grain coatings that decrease the fluid accessibility of other minerals. However, analysis of FIB-SEM images reveals that smectite nano-pores are well connected such that access to underlying minerals is not occluded by smectite coatings. Mineral-specific accessible surfaces are determined, accounting for the connectivity of the pore space with and without connected smectite nano-pores. The large-scale impact of variations in accessibility and dissolution rates are then determined through continuum scale modeling using grid-cell specific information on accessible surface areas. This approach will be compared with a traditional continuum scale model using mineral abundances and common surface area estimates. Ultimately, the effectiveness of advanced surface area characterization to improve mineral dissolution rates will be evaluated by comparison of model results with dissolution rates measured from a flow-through column experiment.

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.

3D surface perception from motion involves a temporal–parietal network

PubMed Central

Beer, Anton L.; Watanabe, Takeo; Ni, Rui; Sasaki, Yuka; Andersen, George J.

2010-01-01

Previous research has suggested that three-dimensional (3D) structure-from-motion (SFM) perception in humans involves several motion-sensitive occipital and parietal brain areas. By contrast, SFM perception in nonhuman primates seems to involve the temporal lobe including areas MT, MST and FST. The present functional magnetic resonance imaging study compared several motion-sensitive regions of interest including the superior temporal sulcus (STS) while human observers viewed horizontally moving dots that defined either a 3D corrugated surface or a 3D random volume. Low-level stimulus features such as dot density and velocity vectors as well as attention were tightly controlled. Consistent with previous research we found that 3D corrugated surfaces elicited stronger responses than random motion in occipital and parietal brain areas including area V3A, the ventral and dorsal intraparietal sulcus, the lateral occipital sulcus and the fusiform gyrus. Additionally, 3D corrugated surfaces elicited stronger activity in area MT and the STS but not in area MST. Brain activity in the STS but not in area MT correlated with interindividual differences in 3D surface perception. Our findings suggest that area MT is involved in the analysis of optic flow patterns such as speed gradients and that the STS in humans plays a greater role in the analysis of 3D SFM than previously thought. PMID:19674088

Central Facilities Area Sewage Lagoon Evaluation

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

Giesbrecht, Alan

2015-03-01

The Central Facilities Area (CFA) located in Butte County, Idaho at Idaho National Laboratory (INL) 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 utilizes a center pivot irrigation sprinkler system. The purpose ofmore » this current study is to update the analysis and conclusions of the December 2013 study. In this current study, the new seepage rate and influent flow rate data have been used to update the calculations, model, and analysis.« less

Airport Surface Traffic Control Systems Deployment Analysis

DOT National Transportation Integrated Search

1974-01-01

The report summarizes the findings of an analysis of ASTC (Airport Surface Traffic Control) system requirements and develops estimates of the deployment potential of proposed system alternatives. The tower control problem areas were investigated by a...

Anatomical and morphological study of the subcoracoacromial canal.

PubMed

Le Reun, O; Lebhar, J; Mateos, F; Voisin, J L; Thomazeau, H; Ropars, M

2016-12-01

Many clinical anatomy studies have looked into how variations in the acromion, coracoacromial ligament (CAL) and subacromial space are associated with rotator cuff injuries. However, no study up to now had defined anatomically the fibro-osseous canal that confines the supraspinatus muscle in the subcoracoacromial space. Through an anatomical study of the scapula, we defined the bone-related parameters of this canal and its anatomical variations. This study on dry bones involved 71 scapulas. With standardised photographs in two orthogonal views (superior and lateral), the surface area of the subcoracoacromial canal and the anatomical parameters making up this canal were defined and measured using image analysis software. The primary analysis evaluated the anatomical parameters of the canal as a function of three canal surface area groups; the secondary analysis looked into how variations in the canal surface area were related to the type of acromion according to the Bigliani classification. Relative to glenoid width, the group with a large canal surface area (L) had significantly less lateral overhang of the acromion than the group with a small canal surface area (S), with ratios of 0.41±0.23 and 0.58±0.3, respectively (P=0.04). The mean length of the CAL was 46±8mm in the L group and 39±9mm in the S group (P=0.003). The coracoacromial arch angle was 38°±11° in the L group and 34°±9° in the S group; the canal surface area was smaller in specimens with a smaller coracoacromial arch angle (P=0.20). Apart from acromial morphology, there could be innate anatomical features of the scapula that predispose people to extrinsic lesions to the supraspinatus tendon (lateral overhang, coracoacromial arch angle) by reducing the subcoracoacromial canal's surface area. Anatomical descriptive study. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Prior-knowledge-based spectral mixture analysis for impervious surface mapping

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

Zhang, Jinshui; He, Chunyang; Zhou, Yuyu

2014-01-03

In this study, we developed a prior-knowledge-based spectral mixture analysis (PKSMA) to map impervious surfaces by using endmembers derived separately for high- and low-density urban regions. First, an urban area was categorized into high- and low-density urban areas, using a multi-step classification method. Next, in high-density urban areas that were assumed to have only vegetation and impervious surfaces (ISs), the Vegetation-Impervious model (V-I) was used in a spectral mixture analysis (SMA) with three endmembers: vegetation, high albedo, and low albedo. In low-density urban areas, the Vegetation-Impervious-Soil model (V-I-S) was used in an SMA analysis with four endmembers: high albedo, lowmore » albedo, soil, and vegetation. The fraction of IS with high and low albedo in each pixel was combined to produce the final IS map. The root mean-square error (RMSE) of the IS map produced using PKSMA was about 11.0%, compared to 14.52% using four-endmember SMA. Particularly in high-density urban areas, PKSMA (RMSE = 6.47%) showed better performance than four-endmember (15.91%). The results indicate that PKSMA can improve IS mapping compared to traditional SMA by using appropriately selected endmembers and is particularly strong in high-density urban areas.« less

Echelon approach to areas of concern in synoptic regional monitoring

USGS Publications Warehouse

Myers, Wayne; Patil, Ganapati P.; Joly, Kyle

1997-01-01

Echelons provide an objective approach to prospecting for areas of potential concern in synoptic regional monitoring of a surface variable. Echelons can be regarded informally as stacked hill forms. The strategy is to identify regions of the surface which are elevated relative to surroundings (Relative ELEVATIONS or RELEVATIONS). These are areas which would continue to expand as islands with receding (virtual) floodwaters. Levels where islands would merge are critical elevations which delimit echelons in the vertical dimension. Families of echelons consist of surface sectors constituting separate islands for deeper waters that merge as water level declines. Pits which would hold water are disregarded in such a progression, but a complementary analysis of pits is obtained using the surface as a virtual mould to cast a counter-surface (bathymetric analysis). An echelon tree is a family tree of echelons with peaks as terminals and the lowest level as root. An echelon tree thus provides a dendrogram representation of surface topology which enables graph theoretic analysis and comparison of surface structures. Echelon top view maps show echelon cover sectors on the base plane. An echelon table summarizes characteristics of echelons as instances or cases of hill form surface structure. Determination of echelons requires only ordinal strength for the surface variable, and is thus appropriate for environmental indices as well as measurements. Since echelons are inherent in a surface rather than perceptual, they provide a basis for computer-intelligent understanding of surfaces. Echelons are given for broad-scale mammalian species richness in Pennsylvania.

Role of Induced and Natural Imbibition in Frac Fluid Transport and Fate in Gas Shales, March 28-29, 2011

EPA Pesticide Factsheets

Hydraulic fracture modeling and fracture surface area calculations determined from pressure decay analysis and reservoir numerical flow simulation support estimates of created hydraulic fracture surface areas of 24-60 MM sq ft.

Analysis of the sorption properties of different soils using water vapour adsorption and potentiometric titration methods

NASA Astrophysics Data System (ADS)

Skic, Kamil; Boguta, Patrycja; Sokołowska, Zofia

2016-07-01

Parameters of specific surface area as well as surface charge were used to determine and compare sorption properties of soils with different physicochemical characteristics. The gravimetric method was used to obtain water vapour isotherms and then specific surface areas, whereas surface charge was estimated from potentiometric titration curves. The specific surface area varied from 12.55 to 132.69 m2 g-1 for Haplic Cambisol and Mollic Gleysol soil, respectively, and generally decreased with pH (R=0.835; α = 0.05) and when bulk density (R=-0.736; α = 0.05) as well as ash content (R=-0.751; α = 0.05) increased. In the case of surface charge, the values ranged from 63.00 to 844.67 μmol g-1 Haplic Fluvisol and Mollic Gleysol, respecively. Organic matter gave significant contributions to the specific surface area and cation exchange capacity due to the large surface area and numerous surface functional groups, containing adsorption sites for water vapour molecules and for ions. The values of cation exchange capacity and specific surface area correlated linearly at the level of R=0.985; α = 0.05.

On-the-fly Numerical Surface Integration for Finite-Difference Poisson-Boltzmann Methods.

PubMed

Cai, Qin; Ye, Xiang; Wang, Jun; Luo, Ray

2011-11-01

Most implicit solvation models require the definition of a molecular surface as the interface that separates the solute in atomic detail from the solvent approximated as a continuous medium. Commonly used surface definitions include the solvent accessible surface (SAS), the solvent excluded surface (SES), and the van der Waals surface. In this study, we present an efficient numerical algorithm to compute the SES and SAS areas to facilitate the applications of finite-difference Poisson-Boltzmann methods in biomolecular simulations. Different from previous numerical approaches, our algorithm is physics-inspired and intimately coupled to the finite-difference Poisson-Boltzmann methods to fully take advantage of its existing data structures. Our analysis shows that the algorithm can achieve very good agreement with the analytical method in the calculation of the SES and SAS areas. Specifically, in our comprehensive test of 1,555 molecules, the average unsigned relative error is 0.27% in the SES area calculations and 1.05% in the SAS area calculations at the grid spacing of 1/2Å. In addition, a systematic correction analysis can be used to improve the accuracy for the coarse-grid SES area calculations, with the average unsigned relative error in the SES areas reduced to 0.13%. These validation studies indicate that the proposed algorithm can be applied to biomolecules over a broad range of sizes and structures. Finally, the numerical algorithm can also be adapted to evaluate the surface integral of either a vector field or a scalar field defined on the molecular surface for additional solvation energetics and force calculations.

Percent area coverage through image analysis

NASA Astrophysics Data System (ADS)

Wong, Chung M.; Hong, Sung M.; Liu, De-Ling

2016-09-01

The notion of percent area coverage (PAC) has been used to characterize surface cleanliness levels in the spacecraft contamination control community. Due to the lack of detailed particle data, PAC has been conventionally calculated by multiplying the particle surface density in predetermined particle size bins by a set of coefficients per MIL-STD-1246C. In deriving the set of coefficients, the surface particle size distribution is assumed to follow a log-normal relation between particle density and particle size, while the cross-sectional area function is given as a combination of regular geometric shapes. For particles with irregular shapes, the cross-sectional area function cannot describe the true particle area and, therefore, may introduce error in the PAC calculation. Other errors may also be introduced by using the lognormal surface particle size distribution function that highly depends on the environmental cleanliness and cleaning process. In this paper, we present PAC measurements from silicon witness wafers that collected fallouts from a fabric material after vibration testing. PAC calculations were performed through analysis of microscope images and compare them to values derived through the MIL-STD-1246C method. Our results showed that the MIL-STD-1246C method does provide a reasonable upper bound to the PAC values determined through image analysis, in particular for PAC values below 0.1.

An analysis of urban thermal characteristics and associated land cover in Tampa Bay and Las Vegas using Landsat satellite data

USGS Publications Warehouse

Xian, George; Crane, Mike

2006-01-01

Remote sensing data from both Landsat 5 and Landsat 7 systems were utilized to assess urban area thermal characteristics in Tampa Bay watershed of west-central Florida, and the Las Vegas valley of southern Nevada. To quantitatively determine urban land use extents and development densities, sub-pixel impervious surface areas were mapped for both areas. The urban–rural boundaries and urban development densities were defined by selecting certain imperviousness threshold values and Landsat thermal bands were used to investigate urban surface thermal patterns. Analysis results suggest that urban surface thermal characteristics and patterns can be identified through qualitatively based urban land use and development density data. Results show the urban area of the Tampa Bay watershed has a daytime heating effect (heat-source), whereas the urban surface in Las Vegas has a daytime cooling effect (heat-sink). These thermal effects strongly correlated with urban development densities where higher percent imperviousness is usually associated with higher surface temperature. Using vegetation canopy coverage information, the spatial and temporal distributions of urban impervious surface and associated thermal characteristics are demonstrated to be very useful sources in quantifying urban land use, development intensity, and urban thermal patterns.

Detecting Changes of Thermal Environment over the Bohai Coastal Region by Spectral Change Vector Analysis

NASA Astrophysics Data System (ADS)

Hu, Y.; Jia, G.

2009-12-01

Change vector analysis (CVA) is an effective approach for detecting and characterizing land-cover change by comparing pairs of multi-spectral and multi-temporal datasets over certain area derived from various satellite platforms. NDVI is considered as an effective detector for biophysical changes due to its sensitivity to red and near infrared signals, while land surface temperature (LST) is considered as a valuable indicator for changes of ground thermal conditions. Here we try to apply CVA over satellite derived LST datasets to detect changes of land surface thermal properties parallel to climate change and anthropogenic influence in a city cluster since 2001. In this study, monthly land surface temperature datasets from 2001-2008 derived from MODIS collection 5 were used to examine change pattern of thermal environment over the Bohai coastal region by using spectral change vector analysis. The results from principle component analysis (PCA) for LST show that the PC 1-3 contain over 80% information on monthly variations and these PCA components represent the main processes of land thermal environment change over the study area. Time series of CVA magnitude combined with land cover information show that greatest change occurred in urban and heavily populated area, featured with expansion of urban heat island, while moderate change appeared in grassland area in the north. However few changes were observed over large plain area and forest area. Strong signals also are related to economy level and especially the events of surface cover change, such as emergence of railway and port. Two main processes were also noticed about the changes of thermal environment. First, weak signal was detected in mostly natural area influenced by interannual climate change in temperate broadleaf forest area. Second, land surface temperature changes were controlled by human activities as 1) moderate change of LST happened in grassland influenced by grazing and 2) urban heat island was intensifier in major cities, such as Beijing and Tianjin. Further, the continual drier climate combined with human actions over past fifties years have intensified land thermal pattern change and the continuation will be an important aspects to understand land surface processes and local climate change. Land surface temperature trends from 2000-2008 over the Bohai coastal region

Evaluation of the Biological Sampling Kit (BiSKit) for Large-Area Surface Sampling

PubMed Central

Buttner, Mark P.; Cruz, Patricia; Stetzenbach, Linda D.; Klima-Comba, Amy K.; Stevens, Vanessa L.; Emanuel, Peter A.

2004-01-01

Current surface sampling methods for microbial contaminants are designed to sample small areas and utilize culture analysis. The total number of microbes recovered is low because a small area is sampled, making detection of a potential pathogen more difficult. Furthermore, sampling of small areas requires a greater number of samples to be collected, which delays the reporting of results, taxes laboratory resources and staffing, and increases analysis costs. A new biological surface sampling method, the Biological Sampling Kit (BiSKit), designed to sample large areas and to be compatible with testing with a variety of technologies, including PCR and immunoassay, was evaluated and compared to other surface sampling strategies. In experimental room trials, wood laminate and metal surfaces were contaminated by aerosolization of Bacillus atrophaeus spores, a simulant for Bacillus anthracis, into the room, followed by settling of the spores onto the test surfaces. The surfaces were sampled with the BiSKit, a cotton-based swab, and a foam-based swab. Samples were analyzed by culturing, quantitative PCR, and immunological assays. The results showed that the large surface area (1 m2) sampled with the BiSKit resulted in concentrations of B. atrophaeus in samples that were up to 10-fold higher than the concentrations obtained with the other methods tested. A comparison of wet and dry sampling with the BiSKit indicated that dry sampling was more efficient (efficiency, 18.4%) than wet sampling (efficiency, 11.3%). The sensitivities of detection of B. atrophaeus on metal surfaces were 42 ± 5.8 CFU/m2 for wet sampling and 100.5 ± 10.2 CFU/m2 for dry sampling. These results demonstrate that the use of a sampling device capable of sampling larger areas results in higher sensitivity than that obtained with currently available methods and has the advantage of sampling larger areas, thus requiring collection of fewer samples per site. PMID:15574898

Effects of surface area and inflow on the performance of stormwater best management practices with uncertainty analysis.

PubMed

Park, Daeryong; Roesner, Larry A

2013-09-01

The performance of stormwater best management practices (BMPs) is affected by BMP geometric and hydrologic factors. The objective of this study was to investigate the effect of BMP surface area and inflow on BMP performance using the k-C* model with uncertainty analysis. Observed total suspended solids (TSS) from detention basins and retention ponds data sets in the International Stormwater BMP Database were used to build and evaluate the model. Detention basins are regarded as dry ponds because they do not always have water, whereas retention ponds have a permanent pool and are considered wet ponds. In this study, Latin hypercube sampling (LHS) was applied to consider uncertainty in both influent event mean concentration (EMC), C(in), and the areal removal constant, k. The latter was estimated from the hydraulic loading rate, q, through use of a power function relationship. Results show that effluent EMC, C(out), decreased as inflow decreased and as BMP surface area increased in both detention basins and retention ponds. However, the change in C(out), depending on inflow and BMP surface area for detention basins, differed from the change in C(out) for retention ponds. Specifically, C(in) was more dominantly associated with the performance of the k-C* model of detention basins than were BMP surface area and inflow. For retention ponds, however, results suggest that BMP surface area and inflow both influenced changes in C(out) as well as C(in). These results suggest that sensitive factors in the performance of the k-C* model are limited to C(in) for detention basins, whereas BMP surface area, inflow, and C(in) are important for retention ponds.

Stochastic response surface methodology: A study in the human health area

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

Oliveira, Teresa A., E-mail: teresa.oliveira@uab.pt; Oliveira, Amílcar, E-mail: amilcar.oliveira@uab.pt; Centro de Estatística e Aplicações, Universidade de Lisboa

2015-03-10

In this paper we review Stochastic Response Surface Methodology as a tool for modeling uncertainty in the context of Risk Analysis. An application in the survival analysis in the breast cancer context is implemented with R software.

Pulmonary diffusional screening and the scaling laws of mammalian metabolic rates

NASA Astrophysics Data System (ADS)

Hou, Chen; Mayo, Michael

2011-12-01

Theoretical considerations suggest that the mammalian metabolic rate is linearly proportional to the surface areas of mitochondria, capillary, and alveolar membranes. However, the scaling exponents of these surface areas to the mammals' body mass (approximately 0.9-1) are higher than exponents of the resting metabolic rate (RMR) to body mass (approximately 0.75), although similar to the one of exercise metabolic rate (EMR); the underlying physiological cause of this mismatch remains unclear. The analysis presented here shows that discrepancies between the scaling exponents of RMR and the relevant surface areas may originate from, at least for the system of alveolar membranes in mammalian lungs, the facts that (i) not all of the surface area is involved in the gas exchange and (ii) that larger mammals host a smaller effective surface area that participates in the material exchange rate. A result of these facts is that lung surface areas unused at rest are activated under heavy breathing conditions (e.g., exercise), wherein larger mammals support larger activated surface areas that provide a higher capability to increase the gas-exchange rate, allowing for mammals to meet, for example, the high energetic demands of foraging and predation.

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

Area-averaged evapotranspiration over a heterogeneous land surface: aggregation of multi-point EC flux measurements with a high-resolution land-cover map and footprint analysis

NASA Astrophysics Data System (ADS)

Xu, Feinan; Wang, Weizhen; Wang, Jiemin; Xu, Ziwei; Qi, Yuan; Wu, Yueru

2017-08-01

The determination of area-averaged evapotranspiration (ET) at the satellite pixel scale/model grid scale over a heterogeneous land surface plays a significant role in developing and improving the parameterization schemes of the remote sensing based ET estimation models and general hydro-meteorological models. The Heihe Watershed Allied Telemetry Experimental Research (HiWATER) flux matrix provided a unique opportunity to build an aggregation scheme for area-averaged fluxes. On the basis of the HiWATER flux matrix dataset and high-resolution land-cover map, this study focused on estimating the area-averaged ET over a heterogeneous landscape with footprint analysis and multivariate regression. The procedure is as follows. Firstly, quality control and uncertainty estimation for the data of the flux matrix, including 17 eddy-covariance (EC) sites and four groups of large-aperture scintillometers (LASs), were carefully done. Secondly, the representativeness of each EC site was quantitatively evaluated; footprint analysis was also performed for each LAS path. Thirdly, based on the high-resolution land-cover map derived from aircraft remote sensing, a flux aggregation method was established combining footprint analysis and multiple-linear regression. Then, the area-averaged sensible heat fluxes obtained from the EC flux matrix were validated by the LAS measurements. Finally, the area-averaged ET of the kernel experimental area of HiWATER was estimated. Compared with the formerly used and rather simple approaches, such as the arithmetic average and area-weighted methods, the present scheme is not only with a much better database, but also has a solid grounding in physics and mathematics in the integration of area-averaged fluxes over a heterogeneous surface. Results from this study, both instantaneous and daily ET at the satellite pixel scale, can be used for the validation of relevant remote sensing models and land surface process models. Furthermore, this work will be extended to the water balance study of the whole Heihe River basin.

Geospatial analysis of spaceborne remote sensing data for assessing disaster impacts and modeling surface runoff in the built-environment

NASA Astrophysics Data System (ADS)

Wodajo, Bikila Teklu

Every year, coastal disasters such as hurricanes and floods claim hundreds of lives and severely damage homes, businesses, and lifeline infrastructure. This research was motivated by the 2005 Hurricane Katrina disaster, which devastated the Mississippi and Louisiana Gulf Coast. The primary objective was to develop a geospatial decision-support system for extracting built-up surfaces and estimating disaster impacts using spaceborne remote sensing satellite imagery. Pre-Katrina 1-m Ikonos imagery of a 5km x 10km area of Gulfport, Mississippi, was used as source data to develop the built-up area and natural surfaces or BANS classification methodology. Autocorrelation of 0.6 or higher values related to spectral reflectance values of groundtruth pixels were used to select spectral bands and establish the BANS decision criteria of unique ranges of reflectance values. Surface classification results using GeoMedia Pro geospatial analysis for Gulfport sample areas, based on BANS criteria and manually drawn polygons, were within +/-7% of the groundtruth. The difference between the BANS results and the groundtruth was statistically not significant. BANS is a significant improvement over other supervised classification methods, which showed only 50% correctly classified pixels. The storm debris and erosion estimation or SDE methodology was developed from analysis of pre- and post-Katrina surface classification results of Gulfport samples. The SDE severity level criteria considered hurricane and flood damages and vulnerability of inhabited built-environment. A linear regression model, with +0.93 Pearson R-value, was developed for predicting SDE as a function of pre-disaster percent built-up area. SDE predictions for Gulfport sample areas, used for validation, were within +/-4% of calculated values. The damage cost model considered maintenance, rehabilitation and reconstruction costs related to infrastructure damage and community impacts of Hurricane Katrina. The developed models were implemented for a study area along I-10 considering the predominantly flood-induced damages in New Orleans. The BANS methodology was calibrated for 0.6-m QuickBird2 multispectral imagery of Karachi Port area in Pakistan. The results were accurate within +/-6% of the groundtruth. Due to its computational simplicity, the unit hydrograph method is recommended for geospatial visualization of surface runoff in the built-environment using BANS surface classification maps and elevations data. Key words. geospatial analysis, satellite imagery, built-environment, hurricane, disaster impacts, runoff.

Microplastics and polycyclic aromatic hydrocarbons (PAHs) in Xiamen coastal areas: Implications for anthropogenic impacts.

PubMed

Tang, Guowen; Liu, Mengyang; Zhou, Qian; He, Haixia; Chen, Kai; Zhang, Haibo; Hu, Jiahui; Huang, Qinghui; Luo, Yongming; Ke, Hongwei; Chen, Bin; Xu, Xiangrong; Cai, Minggang

2018-09-01

Microplastics and polycyclic aromatic hydrocarbons (PAHs) were investigated to study the influence of human activities and to find their possible relationship on the coastal environments, where the coastal areas around Xiamen are undergoing intensive processes of industrialization and urbanization in the southeast China. The abundance of microplastics in Xiamen coastal areas was 103 to 2017particles/m 3 in surface seawater and 76 to 333 particles/kg in sediments. Concentrations of dissolved PAHs varied from 18.1 to 248ng/L in surface seawater. The abundances of microplastics from the Western Harbor in surface seawater and sediments were higher than those from other areas. Foams were dominated in surface seawater samples, however, no foams were found in sediments samples. The microscope selection and FTIR analysis suggested that polyethylene (PE) and polypropylene (PP) were dominant microplastics. The cluster analysis results demonstrated that fibers and granules had the similar sources, and films had considerably correlation with all types of PAHs (3 or 4-ring PAHs and alkylated PAHs). Plastic film mulch from agriculture practice might be a potential source of microplastics in study areas. Results of our study support that river runoff, watershed area, population and urbanization rate influence the distribution of microplastics in estuarine surface water, and the prevalence of microplastic pollution calls for monitoring microplastics at a national scale. Copyright © 2018 Elsevier B.V. All rights reserved.

Technology of surface wastewater purification, including high-rise construction areas

NASA Astrophysics Data System (ADS)

Tsyba, Anna; Skolubovich, Yury

2018-03-01

Despite on the improvements in the quality of high-rise construction areas and industrial wastewater treatment, the pollution of water bodies continues to increase. This is due to the organized and unorganized surface untreated sewage entry into the reservoirs. The qualitative analysis of some cities' surface sewage composition is carried out in the work. Based on the published literature review, the characteristic contamination present in surface wastewater was identified. The paper proposes a new technology for the treatment of surface sewage and presents the results of preliminary studies.

Nanosilver particle formation on a high surface area titanate.

PubMed

Shi, Meng; Lin, Christopher C H; Wu, Lan; Holt, Christopher M B; Mitlin, David; Kuznicki, Steven M

2010-12-01

Titanium based molecular sieves, such as ETS-10, have the ability to exchange silver ions and subsequently support self assembly of stable silver nanoparticles when heated. We report that a high surface area sodium titanate (resembling ETS-2) displays a similar ability to self template silver nanoparticles on its surface. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show high concentrations of silver nanoparticles on the surface of this sodium titanate, formed by thermal reduction of exchanged silver cations. The nanoparticles range in size from 4 to 12 nm, centered at around 6 nm. In addition to SEM and TEM, XRD and surface area analysis were used to characterize the material. The results indicate that this sodium titanate has a high surface area (>263 m2/g), and high ion exchange capacity for silver (30+ wt%) making it an excellent substrate for the exchange and generation of uniform, high-density silver nanoparticles.

Quantitative X-ray computed tomography peritoneography in malignant peritoneal mesothelioma patients receiving intraperitoneal chemotherapy.

PubMed

Leinwand, Joshua C; Zhao, Binsheng; Guo, Xiaotao; Krishnamoorthy, Saravanan; Qi, Jing; Graziano, Joseph H; Slavkovic, Vesna N; Bates, Gleneara E; Lewin, Sharyn N; Allendorf, John D; Chabot, John A; Schwartz, Lawrence H; Taub, Robert N

2013-12-01

Intraperitoneal chemotherapy is used to treat peritoneal surface-spreading malignancies. We sought to determine whether volume and surface area of the intraperitoneal chemotherapy compartments are associated with overall survival and posttreatment glomerular filtration rate (GFR) in malignant peritoneal mesothelioma (MPM) patients. Thirty-eight MPM patients underwent X-ray computed tomography peritoneograms during outpatient intraperitoneal chemotherapy. We calculated volume and surface area of contrast-filled compartments by semiautomated computer algorithm. We tested whether these were associated with overall survival and posttreatment GFR. Decreased likelihood of mortality was associated with larger surface areas (p = 0.0201) and smaller contrast-filled compartment volumes (p = 0.0341), controlling for age, sex, histologic subtype, and presence of residual disease >0.5 cm postoperatively. Larger volumes were associated with higher posttreatment GFR, controlling for pretreatment GFR, body surface area, surface area, and the interaction between body surface area and volume (p = 0.0167). Computed tomography peritoneography is an appropriate modality to assess for maldistribution of intraperitoneal chemotherapy. In addition to identifying catheter failure and frank loculation, quantitative analysis of the contrast-filled compartment's surface area and volume may predict overall survival and cisplatin-induced nephrotoxicity. Prospective studies should be undertaken to confirm and extend these findings to other diseases, including advanced ovarian carcinoma.

Surface area and pore size characteristics of nanoporous gold subjected to thermal, mechanical, or surface modification studied using gas adsorption isotherms, cyclic voltammetry, thermogravimetric analysis, and scanning electron microscopy

PubMed Central

Tan, Yih Horng; Davis, Jason A.; Fujikawa, Kohki; Ganesh, N. Vijaya; Demchenko, Alexei V.

2012-01-01

Nitrogen adsorption/desorption isotherms are used to investigate the Brunauer, Emmett, and Teller (BET) surface area and Barrett-Joyner-Halenda (BJH) pore size distribution of physically modified, thermally annealed, and octadecanethiol functionalized np-Au monoliths. We present the full adsorption-desorption isotherms for N2 gas on np-Au, and observe type IV isotherms and type H1 hysteresis loops. The evolution of the np-Au under various thermal annealing treatments was examined using scanning electron microscopy (SEM). The images of both the exterior and interior of the thermally annealed np-Au show that the porosity of all free standing np-Au structures decreases as the heat treatment temperature increases. The modification of the np-Au surface with a self-assembled monolayer (SAM) of C18-SH (coverage of 2.94 × 1014 molecules cm−2 based from the decomposition of the C18-SH using thermogravimetric analysis (TGA)), was found to reduce the strength of the interaction of nitrogen gas with the np-Au surface, as reflected by a decrease in the ‘C’ parameter of the BET equation. From cyclic voltammetry studies, we found that the surface area of the np-Au monoliths annealed at elevated temperatures followed the same trend with annealing temperature as found in the BET surface area study and SEM morphology characterization. The study highlights the ability to control free-standing nanoporous gold monoliths with high surface area, and well-defined, tunable pore morphology. PMID:22822294

High surface area electrodes by template-free self-assembled hierarchical porous gold architecture.

PubMed

Morag, Ahiud; Golub, Tatiana; Becker, James; Jelinek, Raz

2016-06-15

The electrode active surface area is a crucial determinant in many electrochemical applications and devices. Porous metal substrates have been employed in electrode design, however construction of such materials generally involves multistep processes, generating in many instances electrodes exhibiting incomplete access to internal pore surfaces. Here we describe fabrication of electrodes comprising hierarchical, nano-to-microscale porous gold matrix, synthesized through spontaneous crystallization of gold thiocyanate in water. Cyclic voltammetry analysis revealed that the specific surface area of the conductive nanoporous Au microwires was very high and depended only upon the amount of gold used, not electrode areas or geometries. Application of the electrode in a pseudo-capacitor device is presented. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO2 adsorption performance

NASA Astrophysics Data System (ADS)

Sargazi, Ghasem; Afzali, Daryoush; Mostafavi, Ali; Ebrahimipour, S. Yousef

2017-06-01

This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2k-1 factorial design experiments, and the response surface optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m2/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO2 adsorption.

Dye adsorption onto activated carbons from tyre rubber waste using surface coverage analysis.

PubMed

Mui, Edward L K; Cheung, W H; Valix, Marjorie; McKay, Gordon

2010-07-15

Two types of activated carbons from tyre char (with or without sulphuric acid treatment) were produced via carbon dioxide activation with BET surface areas in the range 59-1118 m(2)/g. Other characterisation tests include micropore and mesopore surface areas and volumes, pH, and elemental compositions, particularly heteroatoms such as nitrogen and sulphur. They were correlated to the adsorption capacity which were in the range of 0.45-0.71 mmol/g (untreated) and 0.62-0.84 mmol/g (acid-treated) for Acid Blue 25. In the case of larger-sized molecules like Acid Yellow 117, capacities were in the range of 0.23-0.42 mmol/g (untreated) and 0.29-0.40 mmol/g (acid-treated). Some tyre carbons exhibit a more superior performance than a microporous, commercial activated carbon (Calgon F400). By modelling the dye adsorption equilibrium data, the Redlich-Peterson isotherm is adopted as it has the lowest SSE. Based on the surface coverage analysis, a novel molecular orientation modelling of adsorbed dyes has been proposed and correlated with surface area and surface charge. For the acid dyes used in this study, molecules were likely to be adsorbed by the mesopore areas. Copyright 2010 Elsevier Inc. All rights reserved.

Enhanced reactivity of nanoscale iron particles through a vacuum annealing process

NASA Astrophysics Data System (ADS)

Riba, Olga; Barnes, Robert J.; Scott, Thomas B.; Gardner, Murray N.; Jackman, Simon A.; Thompson, Ian P.

2011-10-01

A reactivity study was undertaken to compare and assess the rate of dechlorination of chlorinated aliphatic hydrocarbons (CAHs) by annealed and non-annealed nanoscale iron particles. The current study aims to resolve the uncertainties in recently published work studying the effect of the annealing process on the reduction capability of nanoscale Fe particles. Comparison of the normalized rate constants (m2/h/L) obtained for dechlorination reactions of trichloroethene (TCE) and cis-1,2-dichloroethene (cis-1,2-DCE) indicated that annealing nanoscale Fe particles increases their reactivity 30-fold. An electron transfer reaction mechanism for both types of nanoscale particles was found to be responsible for CAH dechlorination, rather than a reduction reaction by activated H2 on the particle surface (i.e., hydrogenation, hydrogenolysis). Surface analysis of the particulate material using X-ray diffraction (XRD) and transmission electron microscopy (TEM) together with surface area measurement by Brunauer, Emmett, Teller (BET) indicate that the vacuum annealing process decreases the surface area and increases crystallinity. BET surface area analysis recorded a decrease in nanoscale Fe particle surface area from 19.0 to 4.8 m2/g and crystallite dimensions inside the particle increased from 8.7 to 18.2 nm as a result of annealing.

New Generation Materials and Structures for Nanophotonics and Nanoelectronics

DTIC Science & Technology

2006-04-30

been investigated using thermogravimetric analysis and FTIR spectroscopy. The nanoparticles appear to have excess surfactants on their surface, but...processes. We continued analysis of the vibrational modes of the InP/II- VI core-shell nanoparticles determined by IR and Raman studies, and initiated...photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), BET surface area analysis , transmission electron microscopy (TEM), and SQUID magnetometry. In

Development of an Interactive Shoreline Management Tool for the Lower Wood River Valley, Oregon - Phase I: Stage-Volume and Stage-Area Relations

USGS Publications Warehouse

Haluska, Tana L.; Snyder, Daniel T.

2007-01-01

This report presents the parcel and inundation area geographic information system (GIS) layers for various surface-water stages. It also presents data tables containing the water stage, inundation area, and water volume relations developed from analysis of detailed land surface elevation derived from Light Detection and Ranging (LiDAR) data recently collected for the Wood River Valley at the northern margin of Agency Lake in Klamath County, Oregon. Former shoreline wetlands that have been cut off from Upper Klamath and Agency Lakes by dikes might in the future be reconnected to Upper Klamath and Agency Lakes by breaching the dikes. Issues of interest associated with restoring wetlands in this way include the area that will be inundated, the volume of water that may be stored, the change in wetland habitat, and the variation in these characteristics as surface-water stage is changed. Products from this analysis can assist water managers in assessing the effect of breaching dikes and changing surface-water stage. The study area is in the approximate former northern margins of Upper Klamath and Agency Lakes in the Wood River Valley.

Potential Bone to Implant Contact Area of Short Versus Standard Implants: An In Vitro Micro-Computed Tomography Analysis.

PubMed

Quaranta, Alessandro; DʼIsidoro, Orlando; Bambini, Fabrizio; Putignano, Angelo

2016-02-01

To compare the available potential bone-implant contact (PBIC) area of standard and short dental implants by micro-computed tomography (μCT) assessment. Three short implants with different diameters (4.5 × 6 mm, 4.1 × 7 mm, and 4.1 × 6 mm) and 2 standard implants (3.5 × 10 mm and 3.3 × 9 mm) with diverse design and surface features were scanned with μCT. Cross-sectional images were obtained. Image data were manually processed to find the plane that corresponds to the most coronal contact point between the crestal bone and implant. The available PBIC was calculated for each sample. Later on, the cross-sectional slices were processed by a 3-dimensional (3D) software, and 3D images of each sample were used for descriptive analysis and display the microtopography and macrotopography. The wide-diameter short implant (4.5 × 6 mm) showed the higher PBIC (210.89 mm) value followed by the standard (178.07 mm and 185.37 mm) and short implants (130.70 mm and 110.70 mm). Wide-diameter short implants show a surface area comparable with standard implants. Micro-CT analysis is a promising technique to evaluate surface area in dental implants with different macrodesign, microdesign, and surface features.

Spatially variable stage-driven groundwater-surface water interaction inferred from time-frequency analysis of distributed temperature sensing data

USGS Publications Warehouse

Mwakanyamale, Kisa; Slater, Lee; Day-Lewis, Frederick D.; Elwaseif, Mehrez; Johnson, Carole D.

2012-01-01

Characterization of groundwater-surface water exchange is essential for improving understanding of contaminant transport between aquifers and rivers. Fiber-optic distributed temperature sensing (FODTS) provides rich spatiotemporal datasets for quantitative and qualitative analysis of groundwater-surface water exchange. We demonstrate how time-frequency analysis of FODTS and synchronous river stage time series from the Columbia River adjacent to the Hanford 300-Area, Richland, Washington, provides spatial information on the strength of stage-driven exchange of uranium contaminated groundwater in response to subsurface heterogeneity. Although used in previous studies, the stage-temperature correlation coefficient proved an unreliable indicator of the stage-driven forcing on groundwater discharge in the presence of other factors influencing river water temperature. In contrast, S-transform analysis of the stage and FODTS data definitively identifies the spatial distribution of discharge zones and provided information on the dominant forcing periods (≥2 d) of the complex dam operations driving stage fluctuations and hence groundwater-surface water exchange at the 300-Area.

Dynamic technique for measuring adsorption in a gas chromatograph

NASA Technical Reports Server (NTRS)

Deuel, C. L.; Hultgren, N. W.; Mobert, M. L.

1973-01-01

Gas-chromatographic procedure, together with mathematical analysis of adsorption isotherm, allows relative surface areas and adsorptive powers for trace concentrations to be determined in a few minutes. Technique may be used to evaluate relative surface areas of different adsorbates, expressed as volume of adsorbent/gram of adsorbate, and to evaluate their relative adsorptive power.

Multiscale Simulations of ALD in Cross Flow Reactors

DOE PAGES

Yanguas-Gil, Angel; Libera, Joseph A.; Elam, Jeffrey W.

2014-08-13

In this study, we have developed a multiscale simulation code that allows us to study the impact of surface chemistry on the coating of large area substrates with high surface area/high aspect-ratio features. Our code, based on open-source libraries, takes advantage of the ALD surface chemistry to achieve an extremely efficient two-way coupling between reactor and feature length scales, and it can provide simulated quartz crystal microbalance and mass spectrometry data at any point of the reactor. By combining experimental surface characterization with simple analysis of growth profiles in a tubular cross flow reactor, we are able to extract amore » minimal set of reactions to effectively model the surface chemistry, including the presence of spurious CVD, to evaluate the impact of surface chemistry on the coating of large, high surface area substrates.« less

Estimation of the specific surface area for a porous carrier.

PubMed

Levstek, Meta; Plazl, Igor; Rouse, Joseph D

2010-03-01

In biofilm systems, treatment performance is primarily dependent upon the available biofilm growth surface area in the reactor. Specific surface area is thus a parameter that allows for making comparisons between different carrier technologies used for wastewater treatment. In this study, we estimated the effective surface area for a spherical, porous polyvinyl alcohol (PVA) gel carrier (Kuraray) that has previously demonstrated effectiveness for retention of autotrophic and heterotrophic biomass. This was accomplished by applying the GPS-X modeling tool (Hydromantis) to a comparative analysis of two moving-bed biofilm reactor (MBBR) systems. One system consisted of a lab-scale reactor that was fed synthetic wastewater under autotrophic conditions where only the nitrification process was studied. The other was a pre-denitrification pilot-scale plant that was fed real, primary-settled wastewater. Calibration of an MBBR process model for both systems indicated an effective specific surface area for PVA gel of 2500 m2/m3, versus a specific surface area of 1000 m2/m3 when only the outer surface of the gel beads is considered. In addition, the maximum specific growth rates for autotrophs and heterotrophs were estimated to be 1.2/day and 6.0/day, respectively.

New Technology-Large-Area Three- Dimensional Surface Profiling Using Only Focused Air-Coupled Ultrasound-Given 1999 R&D 100 Award

NASA Technical Reports Server (NTRS)

Roth, Don J.; Kautz, Harold E.; Abel, Phillip B.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

2000-01-01

Surface topography, which significantly affects the performance of many industrial components, is normally measured with diamond-tip profilometry over small areas or with optical scattering methods over larger areas. To develop air-coupled surface profilometry, the NASA Glenn Research Center at Lewis Field initiated a Space Act Agreement with Sonix, Inc., through two Glenn programs, the Advanced High Temperature Engine Materials Program (HITEMP) and COMMTECH. The work resulted in quantitative surface topography profiles obtained using only high-frequency, focused ultrasonic pulses in air. The method is nondestructive, noninvasive, and noncontact, and it does not require light-reflective surfaces. Air surface profiling may be desirable when diamond-tip or laserbased methods are impractical, such as over large areas, when a significant depth range is required, or for curved surfaces. When the configuration is optimized, the method is reasonably rapid and all the quantitative analysis facilities are online, including two- and three-dimensional visualization, extreme value filtering (for faulty data), and leveling.

Surface Heat Balance Analysis of Tainan City on March 6, 2001 Using ASTER and Formosat-2 Data

PubMed Central

Kato, Soushi; Yamaguchi, Yasushi; Liu, Cheng-Chien; Sun, Chen-Yi

2008-01-01

The urban heat island phenomenon occurs as a mixed result of anthropogenic heat discharge, decreased vegetation, and increased artificial impervious surfaces. To clarify the contribution of each factor to the urban heat island, it is necessary to evaluate the surface heat balance. Satellite remote sensing data of Tainan City, Taiwan, obtained from Terra ASTER and Formosat-2 were used to estimate surface heat balance in this study. ASTER data is suitable for analyzing heat balance because of the wide spectral range. We used Formosat-2 multispectral data to classify the land surface, which was used to interpolate some surface parameters for estimating heat fluxes. Because of the high spatial resolution of the Formosat-2 image, more roads, open spaces and small vegetation areas could be distinguished from buildings in urban areas; however, misclassifications of land cover in such areas using ASTER data would overestimate the sensible heat flux. On the other hand, the small vegetated areas detected from the Formosat-2 image slightly increased the estimation of latent heat flux. As a result, the storage heat flux derived from Formosat-2 is higher than that derived from ASTER data in most areas. From these results, we can conclude that the higher resolution land coverage map increases accuracy of the heat balance analysis. Storage heat flux occupies about 60 to 80% of the net radiation in most of the artificial surface areas in spite of their usages. Because of the homogeneity of the building roof materials, there is no contrast between the storage heat flux in business and residential areas. In sparsely vegetated urban areas, more heat is stored and latent heat is smaller than that in the forested suburbs. This result implies that density of vegetation has a significant influence in decreasing temperatures. PMID:27873856

Effect of specific surface area of MWCNTS on surface roughness and delamination in drilling Epoxy/Glass Fabric Composite

NASA Astrophysics Data System (ADS)

Ponnuvel, S.; Ananth, M. Prem

2018-03-01

In this study the effect of specific surface area of the MWCNTs on the drilled hole qualities was investigated. Epoxy araldite LY556 with hardener HY951 and E-glass coarse plain weave fabric are used for the fabrication of reference material (specimen A). Multi-WalledCarbon Nanotubes (MWCNTs) with diameters <8 nm and 20–30 nm are used for the fabrication of study materials, namely specimen B and specimen C respectively. In specimen B the epoxy resin was filled with MWCNTs having a specific surface area >500 m2 g‑1. MWCNTs in specimen C had a specific surface area >110 m2 g‑1. Drilling experiments were conducted on all the three specimens. Two dimensional delamination factor and the surface roughness of the inner wall of the drilled holes were investigated using Grey Relational Analysis (GRA) and Analysis of variance (ANOVA). Two dimensional delamination factor showed better performance from specimen B and specimen C in comparison with specimen A suggesting improvement in the bonding between epoxy and the glass fiber in the presence of MWCNTs. Similar observations were made for surface roughness of the inner wall of the drilled holes at 1250 rpm. Whereas the presence of MWCNTs (Specimen B and specimen C) produced poor surface finish at 500 rpm in comparison with specimen A. Variations in the hole quality characteristics between specimen B and specimen C was marginal with better observations in specimen C.

The Genetic Association Between Neocortical Volume and General Cognitive Ability Is Driven by Global Surface Area Rather Than Thickness.

PubMed

Vuoksimaa, Eero; Panizzon, Matthew S; Chen, Chi-Hua; Fiecas, Mark; Eyler, Lisa T; Fennema-Notestine, Christine; Hagler, Donald J; Fischl, Bruce; Franz, Carol E; Jak, Amy; Lyons, Michael J; Neale, Michael C; Rinker, Daniel A; Thompson, Wesley K; Tsuang, Ming T; Dale, Anders M; Kremen, William S

2015-08-01

Total gray matter volume is associated with general cognitive ability (GCA), an association mediated by genetic factors. It is expectable that total neocortical volume should be similarly associated with GCA. Neocortical volume is the product of thickness and surface area, but global thickness and surface area are unrelated phenotypically and genetically in humans. The nature of the genetic association between GCA and either of these 2 cortical dimensions has not been examined. Humans possess greater cognitive capacity than other species, and surface area increases appear to be the primary driver of the increased size of the human cortex. Thus, we expected neocortical surface area to be more strongly associated with cognition than thickness. Using multivariate genetic analysis in 515 middle-aged twins, we demonstrated that both the phenotypic and genetic associations between neocortical volume and GCA are driven primarily by surface area rather than thickness. Results were generally similar for each of 4 specific cognitive abilities that comprised the GCA measure. Our results suggest that emphasis on neocortical surface area, rather than thickness, could be more fruitful for elucidating neocortical-GCA associations and identifying specific genes underlying those associations. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO{sub 2} adsorption performance

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

Sargazi, Ghasem, E-mail: g.sargazi@gmail.com; Young Researchers Society, Shahid Bahonar University of Kerman, Kerman, Iran; Afzali, Daryoush, E-mail: daryoush_afzali@yahoo.com

2017-06-15

This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2{sup k-1} factorial design experiments, and the response surfacemore » optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m{sup 2}/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO{sub 2} adsorption. - Graphical abstract: A facile route was used for fabrication of a new metal -organic framework based on tantalum nanostructures that have high surface area, considerable porosity, homogenous morphology, and small size distribution.« less

Why mushrooms form gills: efficiency of the lamellate morphology

PubMed Central

FISCHER, Mark W. F.; MONEY, Nicholas P.

2009-01-01

Gilled mushrooms are produced by multiple orders within the Agaricomycetes. Some species form a single array of unbranched radial gills beneath their caps, many others produce multiple files of lamellulae between the primary gills, and branched gills are also common. In this largely theoretical study we modeled the effects of different gill arrangements on the total surface area for spore production. Relative to spore production over a flat surface, gills achieve a maximum 20-fold increase in surface area. The branching of gills produces the same increase in surface area as the formation of freestanding lamellulae (short gills). The addition of lamellulae between every second gill would offer a slightly greater increase in surface area in comparison to the addition of lamellulae between every pair of opposing gills, but this morphology does not appear in nature. Analysis of photographs of mushrooms demonstrates an excellent match between natural gill arrangements and configurations predicted by our model. PMID:20965062

Retrospective analysis of pulsed radiofrequency energy therapy use in the treatment of chronic pressure ulcers.

PubMed

Conner-Kerr, Teresa; Isenberg, Richard A

2012-06-01

: The purpose of the study was to evaluate the benefit of using pulsed radiofrequency energy (PRFE) therapy in the treatment of chronic pressure ulcers. : A retrospective analysis was performed using case series data from the Provant Wound Registry, which consists of demographic characteristics and wound healing outcomes for patients treated with the Provant Therapy System. : The analysis subset consisted of data from 39 distinct centers, including both residential and ambulatory care facilities. : The analysis included data from 89 patients. The majority of patients (89%) were cared for in residential facilities, whereas 11% of patients were cared for in ambulatory care facilities. : Specific outcomes that assessed wound healing between the initial time point and at the 4-week follow-up were as follows: percent wound surface area reduction (PWAR), proportion of wounds achieving 50% reduction or greater in wound surface area (50% PWAR), and the rate of wound healing (wound healing trajectory in centimeters squared per day). : Overall, there was a 51% median reduction in wound surface area (PWAR) after 4 weeks of PRFE therapy for wounds in the study, with 51% of wounds (56/110) achieving 50% reduction or greater in wound surface area (50% PWAR). Rate of healing measurements for the overall study group showed a median wound healing trajectory of 0.13 cm/d at 4 weeks. : Compared with historical controls and other studies using similar surrogate wound healing markers, these results suggest PRFE therapy is a beneficial adjuvant treatment option for healing chronic pressure ulcers.

14 CFR Appendix B to Part 91 - Authorizations To Exceed Mach 1 (§ 91.817)

Code of Federal Regulations, 2010 CFR

2010-01-01

..., including an environmental analysis of that area meeting the requirements of paragraph (b) of this section... reach the surface outside of the designated test area. (d) An application is denied if the Administrator... number of 1 will not cause a measurable sonic boom overpressure to reach the surface. (b) For a flight...

14 CFR Appendix B to Part 91 - Authorizations To Exceed Mach 1 (§ 91.817)

Code of Federal Regulations, 2011 CFR

2011-01-01

..., including an environmental analysis of that area meeting the requirements of paragraph (b) of this section... reach the surface outside of the designated test area. (d) An application is denied if the Administrator... number of 1 will not cause a measurable sonic boom overpressure to reach the surface. (b) For a flight...

Examination of Spectral Transformations on Spectral Mixture Analysis

NASA Astrophysics Data System (ADS)

Deng, Y.; Wu, C.

2018-04-01

While many spectral transformation techniques have been applied on spectral mixture analysis (SMA), few study examined their necessity and applicability. This paper focused on exploring the difference between spectrally transformed schemes and untransformed scheme to find out which transformed scheme performed better in SMA. In particular, nine spectrally transformed schemes as well as untransformed scheme were examined in two study areas. Each transformed scheme was tested 100 times using different endmember classes' spectra under the endmember model of vegetation- high albedo impervious surface area-low albedo impervious surface area-soil (V-ISAh-ISAl-S). Performance of each scheme was assessed based on mean absolute error (MAE). Statistical analysis technique, Paired-Samples T test, was applied to test the significance of mean MAEs' difference between transformed and untransformed schemes. Results demonstrated that only NSMA could exceed the untransformed scheme in all study areas. Some transformed schemes showed unstable performance since they outperformed the untransformed scheme in one area but weakened the SMA result in another region.

Comparative studies of industrial grade carbon black powders

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

Chawla, Komal, E-mail: komalchawla.rs@gmail.com; Chauhan, Alok P. S., E-mail: chauhan.alok@gmail.com, E-mail: alok.chauhan@alumni.stonybrook.edu

Comparative studies of two dissimilar industrial grade Carbon Black (CB) powders (N375 and N405) were conducted. The structure, surface area and particle size are the three important characteristics of CB powder that determine their processability and application as filler in preparing rubber compounds. The powders were characterized for their structure using dibutyl phthalate absorption (DBPA), particle size via laser particle size analyzer and surface area by nitrogen adsorption method. The structural characterization showed that N405 had lower DBPA in comparison to N375, confirming low structure of N405 grade CB powder. It was observed from the particle size analysis that N375more » was coarser than N405 grade CB. The total surface area values were determined by the BET method based on the cross sectional area of the nitrogen molecule. N375, a coarse grade CB powder with high structure, depicted less surface area as compared to N405.« less

On the theory of drainage area for regular and non-regular points.

PubMed

Bonetti, S; Bragg, A D; Porporato, A

2018-03-01

The drainage area is an important, non-local property of a landscape, which controls surface and subsurface hydrological fluxes. Its role in numerous ecohydrological and geomorphological applications has given rise to several numerical methods for its computation. However, its theoretical analysis has lagged behind. Only recently, an analytical definition for the specific catchment area was proposed (Gallant & Hutchinson. 2011 Water Resour. Res. 47 , W05535. (doi:10.1029/2009WR008540)), with the derivation of a differential equation whose validity is limited to regular points of the watershed. Here, we show that such a differential equation can be derived from a continuity equation (Chen et al. 2014 Geomorphology 219 , 68-86. (doi:10.1016/j.geomorph.2014.04.037)) and extend the theory to critical and singular points both by applying Gauss's theorem and by means of a dynamical systems approach to define basins of attraction of local surface minima. Simple analytical examples as well as applications to more complex topographic surfaces are examined. The theoretical description of topographic features and properties, such as the drainage area, channel lines and watershed divides, can be broadly adopted to develop and test the numerical algorithms currently used in digital terrain analysis for the computation of the drainage area, as well as for the theoretical analysis of landscape evolution and stability.

On the theory of drainage area for regular and non-regular points

NASA Astrophysics Data System (ADS)

Bonetti, S.; Bragg, A. D.; Porporato, A.

2018-03-01

The drainage area is an important, non-local property of a landscape, which controls surface and subsurface hydrological fluxes. Its role in numerous ecohydrological and geomorphological applications has given rise to several numerical methods for its computation. However, its theoretical analysis has lagged behind. Only recently, an analytical definition for the specific catchment area was proposed (Gallant & Hutchinson. 2011 Water Resour. Res. 47, W05535. (doi:10.1029/2009WR008540)), with the derivation of a differential equation whose validity is limited to regular points of the watershed. Here, we show that such a differential equation can be derived from a continuity equation (Chen et al. 2014 Geomorphology 219, 68-86. (doi:10.1016/j.geomorph.2014.04.037)) and extend the theory to critical and singular points both by applying Gauss's theorem and by means of a dynamical systems approach to define basins of attraction of local surface minima. Simple analytical examples as well as applications to more complex topographic surfaces are examined. The theoretical description of topographic features and properties, such as the drainage area, channel lines and watershed divides, can be broadly adopted to develop and test the numerical algorithms currently used in digital terrain analysis for the computation of the drainage area, as well as for the theoretical analysis of landscape evolution and stability.

Trend-surface analysis of the structure of the Ste. Genevieve limestone in the Effingham, Illinois, area

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

Stevenson, D.

1970-01-01

Recent studies of oil accumulations in the Ste. Genevieve Limestone Formation in Illinois demonstrate the usefulness of fitting third-order trend surfaces to structural data and analyzing the residuals calculated by subtracting the trend surface from the structure surface. Known oil pools are located in areas having positive residual values. This type of investigation, supplemented by conventional structural and stratigraphic studies, was performed on a 9-township (approx. 324 sq miles) area in Effingham and Shelby counties, Illinois. The known oil pools in the oolite and sandstone lenses of the Ste. Genevieve Formation lie within positive residuals resulting from the difference betweenmore » a third-order trend surface and the structural surface on top of the Ste. Genevieve. A composite map outlining areas where present anticlinal noses, sandstone lenses, and positive residuals lie in close proximity to each other is included in this report to indicate places where future exploration for Ste. Genevieve oil would have the greatest chance for success.« less

Evaluation of surface water resources from machine-processing of ERTS multispectral data

NASA Technical Reports Server (NTRS)

Mausel, P. W.; Todd, W. J.; Baumgardner, M. F.; Mitchell, R. A.; Cook, J. P.

1976-01-01

The surface water resources of a large metropolitan area, Marion County (Indianapolis), Indiana, are studied in order to assess the potential value of ERTS spectral analysis to water resources problems. The results of the research indicate that all surface water bodies over 0.5 ha were identified accurately from ERTS multispectral analysis. Five distinct classes of water were identified and correlated with parameters which included: degree of water siltiness; depth of water; presence of macro and micro biotic forms in the water; and presence of various chemical concentrations in the water. The machine processing of ERTS spectral data used alone or in conjunction with conventional sources of hydrological information can lead to the monitoring of area of surface water bodies; estimated volume of selected surface water bodies; differences in degree of silt and clay suspended in water and degree of water eutrophication related to chemical concentrations.

Breast Implant-Associated Anaplastic Large Cell Lymphoma in Australia and New Zealand: High-Surface-Area Textured Implants Are Associated with Increased Risk.

PubMed

Loch-Wilkinson, Anna; Beath, Kenneth J; Knight, Robert John William; Wessels, William Louis Fick; Magnusson, Mark; Papadopoulos, Tim; Connell, Tony; Lofts, Julian; Locke, Michelle; Hopper, Ingrid; Cooter, Rodney; Vickery, Karen; Joshi, Preeti Avinash; Prince, H Miles; Deva, Anand K

2017-10-01

The association between breast implants and breast implant-associated anaplastic large cell lymphoma (ALCL) has been confirmed. Implant-related risk has been difficult to estimate to date due to incomplete datasets. All cases in Australia and New Zealand were identified and analyzed. Textured implants reported in this group were subjected to surface area analysis. Sales data from three leading breast implant manufacturers (i.e., Mentor, Allergan, and Silimed) dating back to 1999 were secured to estimate implant-specific risk. Fifty-five cases of breast implant-associated ALCL were diagnosed in Australia and New Zealand between 2007 and 2016. The mean age of patients was 47.1 years and the mean time of implant exposure was 7.46 years. There were four deaths in the series related to mass and/or metastatic presentation. All patients were exposed to textured implants. Surface area analysis confirmed that higher surface area was associated with 64 of the 75 implants used (85.3 percent). Biocell salt loss textured (Allergan, Inamed, and McGhan) implants accounted for 58.7 percent of the implants used in this series. Comparative analysis showed the risk of developing breast implant-associated ALCL to be 14.11 times higher with Biocell textured implants and 10.84 higher with polyurethane (Silimed) textured implants compared with Siltex textured implants. This study has calculated implant-specific risk of breast implant-associated ALCL. Higher-surface-area textured implants have been shown to significantly increase the risk of breast implant-associated ALCL in Australia and New Zealand. The authors present a unifying hypothesis to explain these observations.

A fundamental approach to adhesion: Synthesis, surface analysis, thermodynamics and mechanics. [acid-base properties of titanium 6-4 surfaces

NASA Technical Reports Server (NTRS)

Siriwardane, R.; Wightman, J. P.

1980-01-01

The acid-base properties of titanium 6-4 plates (low surface area) were investigated after three different pretreatments, namely Turco, phosphate-fluoride and Pasa-Jell. A series of indicators was used and color changes were detected using diffuse reflectance visible spectroscopy. Electron spectroscopy for chemical analysis was used to examine the indicator on the Ti 6-4 surface. Specular reflectance infra-red spectroscopy was used to study the adsorption of stearic acid from cyclohexane solutions on the Ti 6-4 surface.

The effect of a defective BSF layer on solar cell open circuit voltage. [Back Surface Field

NASA Technical Reports Server (NTRS)

Weizer, V. G.

1985-01-01

A straightforward analysis of special limiting cases has permitted the determination of the range of possible open circuit voltage losses due to a defective BSF (back surface field) layer. An important result of the analysis is the finding that it is possible to have a fully effective BSF region, regardless of the spatial distribution of the defective areas, as long as the total defective area is reduced below certain limits. Distributed defects were found to be much more harmful than lumped defects.

Contact Analysis of Nominally Flat Surfaces

DTIC Science & Technology

2008-06-01

to analyze the simple case of Hertz-contact (a spherical body in contact with a rigid flat plane) and determine the change in contact area with...next major area was in the Hertz Contact Theory. This area allowed the authors to develop an analytical solution. The third major area was in the... bodies came into contact with one another. This research concluded with the development and testing of the Finite Element Analysis Program (FEAP) using

Apollo 15 time and motion study

NASA Technical Reports Server (NTRS)

Kubis, J. F.; Elrod, J. T.; Rusnak, R.; Barnes, J. E.

1972-01-01

A time and motion study of Apollo 15 lunar surface activity led to examination of four distinct areas of crewmen activity. These areas are: an analysis of lunar mobility, a comparative analysis of tasks performed in 1-g training and lunar EVA, an analysis of the metabolic cost of two activities that are performed in several EVAs, and a fall/near-fall analysis. An analysis of mobility showed that the crewmen used three basic mobility patterns (modified walk, hop, side step) while on the lunar surface. These mobility patterns were utilized as adaptive modes to compensate for the uneven terrain and varied soil conditions that the crewmen encountered. A comparison of the time required to perform tasks at the final 1-g lunar EVA training sessions and the time required to perform the same task on the lunar surface indicates that, in almost all cases, it took significantly more time (on the order of 40%) to perform tasks on the moon. This increased time was observed even after extraneous factors (e.g., hardware difficulties) were factored out.

Investigation of the low-depression velocity layer in desert area by multichannel analysis of surface-wave method

USGS Publications Warehouse

Cheng, S.; Tian, G.; Xia, J.; He, H.; Shi, Z.; ,

2004-01-01

The multichannel analysis of surface-wave method (MASW) is a newly development method. The method has been employed in various applications in environmental and engineering geophysics overseas. However, It can only be found a few case studies in China. Most importantly, there is no application of the MASW in desert area in China or abroad. We present a case study of investigating the low-depression velocity in Temple of North Taba Area in Erdos Basin. The MASW method successfully defined the low-depression velocity layer in the desert area. Comparing results obtained by the MASW method with results by refraction seismic method, we discussed efficiency and simplicity of applying the MASW method in the desert area. It is proved that the maximum investigation depth can reach 60m in the study area when the acquisition and procession parameters are carefully chosen. The MASW method can remedy the incompetence of the refraction method and the micro-seismograph log method in low-depression velocity layer's investigation. The MASW method is also a powerful tool in investigation of near-surface complicated materials and possesses many unique advantages.

Analysis of Global Urban Temperature Trends and Urbanization Impacts

NASA Astrophysics Data System (ADS)

Lee, K. I.; Ryu, J.; Jeon, S. W.

2018-04-01

Due to urbanization, urban areas are shrinking green spaces and increasing concrete, asphalt pavement. So urban climates are different from non-urban areas. In addition, long-term macroscopic studies of urban climate change are becoming more important as global urbanization affects global warming. To do this, it is necessary to analyze the effect of urbanization on the temporal change in urban temperature with the same temperature data and standards for urban areas around the world. In this study, time series analysis was performed with the maximum, minimum, mean and standard values of surface temperature during the from 1980 to 2010 and analyzed the effect of urbanization through linear regression analysis with variables (population, night light, NDVI, urban area). As a result, the minimum value of the surface temperature of the urban area reflects an increase by a rate of 0.28K decade-1 over the past 31 years, the maximum value reflects an increase by a rate of 0.372K decade-1, the mean value reflects an increase by a rate of 0.208 decade-1, and the standard deviation reflects a decrease by rate of 0.023K decade-1. And the change of surface temperature in urban areas is affected by urbanization related to land cover such as decrease of greenery and increase of pavement area, but socioeconomic variables are less influential than NDVI in this study. This study are expected to provide an approach to future research and policy-planning for urban temperature change and urbanization impacts.

Preparation and Characterization of Impregnated Commercial Rice Husks Activated Carbon with Piperazine for Carbon Dioxide (CO2) Capture

NASA Astrophysics Data System (ADS)

Masoum Raman, S. N.; Ismail, N. A.; Jamari, S. S.

2017-06-01

Development of effective materials for carbon dioxide (CO2) capture technology is a fundamental importance to reduce CO2 emissions. This work establishes the addition of amine functional group on the surface of activated carbon to further improve the adsorption capacity of CO2. Rice husks activated carbon were modified using wet impregnation method by introducing piperazine onto the activated carbon surfaces at different concentrations and mixture ratios. These modified activated carbons were characterized by using X-Ray Diffraction (XRD), Brunauer, Emmett and Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy (FESEM). The results from XRD analysis show the presence of polyethylene butane at diffraction angles of 21.8° and 36.2° for modified activated carbon with increasing intensity corresponding to increase in piperazine concentration. BET results found the surface area and pore volume of non-impregnated activated carbon to be 126.69 m2/g and 0.081 cm3/g respectively, while the modified activated carbons with 4M of piperazine have lower surface area and pore volume which is 6.77 m2/g and 0.015 cm3/g respectively. At 10M concentration, the surface area and pore volume are the lowest which is 4.48 m2/g and 0.0065 cm3/g respectively. These results indicate the piperazine being filled inside the activated carbon pores thus, lowering the surface area and pore volume of the activated carbon. From the FTIR analysis, the presence of peaks at 3312 cm-1 and 1636 cm-1 proved the existence of reaction between carboxyl groups on the activated carbon surfaces with piperazine. The surface morphology of activated carbon can be clearly seen through FESEM analysis. The modified activated carbon contains fewer pores than non-modified activated carbon as the pores have been covered with piperazine.

Geostatistical Analysis of Surface Temperature and In-Situ Soil Moisture Using LST Time-Series from Modis

NASA Astrophysics Data System (ADS)

Sohrabinia, M.; Rack, W.; Zawar-Reza, P.

2012-07-01

The objective of this analysis is to provide a quantitative estimate of the fluctuations of land surface temperature (LST) with varying near surface soil moisture (SM) on different land-cover (LC) types. The study area is located in the Canterbury Plains in the South Island of New Zealand. Time series of LST from the MODerate resolution Imaging Spectro-radiometer (MODIS) have been analysed statistically to study the relationship between the surface skin temperature and near-surface SM. In-situ measurements of the skin temperature and surface SM with a quasi-experimental design over multiple LC types are used for validation. Correlations between MODIS LST and in-situ SM, as well as in-situ surface temperature and SM are calculated. The in-situ measurements and MODIS data are collected from various LC types. Pearson's r correlation coefficient and linear regression are used to fit the MODIS LST and surface skin temperature with near-surface SM. There was no significant correlation between time-series of MODIS LST and near-surface SM from the initial analysis, however, careful analysis of the data showed significant correlation between the two parameters. Night-time series of the in-situ surface temperature and SM from a 12 hour period over Irrigated-Crop, Mixed-Grass, Forest, Barren and Open- Grass showed inverse correlations of -0.47, -0.68, -0.74, -0.88 and -0.93, respectively. These results indicated that the relationship between near-surface SM and LST in short-terms (12 to 24 hours) is strong, however, remotely sensed LST with higher temporal resolution is required to establish this relationship in such time-scales. This method can be used to study near-surface SM using more frequent LST observations from a geostationary satellite over the study area.

Comparison of Exposure in the Kaplan Versus the Kocher Approach in the Treatment of Radial Head Fractures.

PubMed

Barnes, Leslie Fink; Lombardi, Joseph; Gardner, Thomas R; Strauch, Robert J; Rosenwasser, Melvin P

2018-01-01

The aim of this study was to compare the complete visible surface area of the radial head, neck, and coronoid in the Kaplan and Kocher approaches to the lateral elbow. The hypothesis was that the Kaplan approach would afford greater visibility due to the differential anatomy of the intermuscular planes. Ten cadavers were dissected with the Kaplan and Kocher approaches, and the visible surface area was measured in situ using a 3-dimensional digitizer. Six measurements were taken for each approach by 2 surgeons, and the mean of these measurements were analyzed. The mean surface area visible with the lateral collateral ligament (LCL) preserved in the Kaplan approach was 616.6 mm 2 in comparison with the surface area of 136.2 mm 2 visible in the Kocher approach when the LCL was preserved. Using a 2-way analysis of variance, the difference between these 2 approaches was statistically significant. When the LCL complex was incised in the Kocher approach, the average visible surface area of the Kocher approach was 456.1 mm 2 and was statistically less than the Kaplan approach. The average surface area of the coronoid visible using a proximally extended Kaplan approach was 197.8 mm 2 . The Kaplan approach affords significantly greater visible surface area of the proximal radius than the Kocher approach.

User's manual for University of Arizona APART program (Analysis Program - Arizona Radiation Trace)

NASA Technical Reports Server (NTRS)

Breault, R. P.

1975-01-01

A description and operating instructions for the Analysis Program Arizona Radiation Trace (APART) are given. This is a computer program that is able to efficiently and accurately predict the off-axis rejection characteristics of unwanted stray radiation for complex rotationally symmetric optical systems. The program first determines the critical objects or areas that scatter radiation to the image plane either directly or through imaging elements: this provides the opportunity to modify, if necessary, the design so that the number of critical areas seen by the image plane is reduced or the radiation to these critical areas is minimized. Next, the power distribution reaching the image plane and a sectional power map of all internal surfaces are computed. Angular information is also provided that relates the angle by which the radiation came into a surface to the angle by which the radiation is scattered out of the surface.

Precise montaging and metric quantification of retinal surface area from ultra-widefield fundus photography and fluorescein angiography.

PubMed

Croft, Daniel E; van Hemert, Jano; Wykoff, Charles C; Clifton, David; Verhoek, Michael; Fleming, Alan; Brown, David M

2014-01-01

Accurate quantification of retinal surface area from ultra-widefield (UWF) images is challenging due to warping produced when the retina is projected onto a two-dimensional plane for analysis. By accounting for this, the authors sought to precisely montage and accurately quantify retinal surface area in square millimeters. Montages were created using Optos 200Tx (Optos, Dunfermline, U.K.) images taken at different gaze angles. A transformation projected the images to their correct location on a three-dimensional model. Area was quantified with spherical trigonometry. Warping, precision, and accuracy were assessed. Uncorrected, posterior pixels represented up to 79% greater surface area than peripheral pixels. Assessing precision, a standard region was quantified across 10 montages of the same eye (RSD: 0.7%; mean: 408.97 mm(2); range: 405.34-413.87 mm(2)). Assessing accuracy, 50 patients' disc areas were quantified (mean: 2.21 mm(2); SE: 0.06 mm(2)), and the results fell within the normative range. By accounting for warping inherent in UWF images, precise montaging and accurate quantification of retinal surface area in square millimeters were achieved. Copyright 2014, SLACK Incorporated.

Color analysis and image rendering of woodblock prints with oil-based ink

NASA Astrophysics Data System (ADS)

Horiuchi, Takahiko; Tanimoto, Tetsushi; Tominaga, Shoji

2012-01-01

This paper proposes a method for analyzing the color characteristics of woodblock prints having oil-based ink and rendering realistic images based on camera data. The analysis results of woodblock prints show some characteristic features in comparison with oil paintings: 1) A woodblock print can be divided into several cluster areas, each with similar surface spectral reflectance; and 2) strong specular reflection from the influence of overlapping paints arises only in specific cluster areas. By considering these properties, we develop an effective rendering algorithm by modifying our previous algorithm for oil paintings. A set of surface spectral reflectances of a woodblock print is represented by using only a small number of average surface spectral reflectances and the registered scaling coefficients, whereas the previous algorithm for oil paintings required surface spectral reflectances of high dimension at all pixels. In the rendering process, in order to reproduce the strong specular reflection in specific cluster areas, we use two sets of parameters in the Torrance-Sparrow model for cluster areas with or without strong specular reflection. An experiment on a woodblock printing with oil-based ink was performed to demonstrate the feasibility of the proposed method.

Thermal Desorption Analysis of Effective Specific Soil Surface Area

NASA Astrophysics Data System (ADS)

Smagin, A. V.; Bashina, A. S.; Klyueva, V. V.; Kubareva, A. V.

2017-12-01

A new method of assessing the effective specific surface area based on the successive thermal desorption of water vapor at different temperature stages of sample drying is analyzed in comparison with the conventional static adsorption method using a representative set of soil samples of different genesis and degree of dispersion. The theory of the method uses the fundamental relationship between the thermodynamic water potential (Ψ) and the absolute temperature of drying ( T): Ψ = Q - aT, where Q is the specific heat of vaporization, and a is the physically based parameter related to the initial temperature and relative humidity of the air in the external thermodynamic reservoir (laboratory). From gravimetric data on the mass fraction of water ( W) and the Ψ value, Polyanyi potential curves ( W(Ψ)) for the studied samples are plotted. Water sorption isotherms are then calculated, from which the capacity of monolayer and the target effective specific surface area are determined using the BET theory. Comparative analysis shows that the new method well agrees with the conventional estimation of the degree of dispersion by the BET and Kutilek methods in a wide range of specific surface area values between 10 and 250 m2/g.

Electrodeposition of Highly Porous Pt Nanoparticles Studied by Quantitative 3D Electron Tomography: Influence of Growth Mechanisms and Potential Cycling on the Active Surface Area.

PubMed

Ustarroz, Jon; Geboes, Bart; Vanrompay, Hans; Sentosun, Kadir; Bals, Sara; Breugelmans, Tom; Hubin, Annick

2017-05-17

Nanoporous Pt nanoparticles (NPs) are promising fuel cell catalysts due to their large surface area and increased electrocatalytic activity toward the oxygen reduction reaction (ORR). Herein, we report on the influence of the growth mechanisms on the surface properties of electrodeposited Pt dendritic NPs with large surface areas. The electrochemically active surface was studied by hydrogen underpotential deposition (H UPD) and compared for the first time to high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) quantitative 3D electron tomography of individual nanoparticles. Large nucleation overpotential leads to a large surface coverage of roughened spheroids, which provide a large roughness factor (R f ) but low mass-specific electrochemically active surface area (EASA). Lowering the nucleation overpotential leads to highly porous Pt NPs with pores stretching to the center of the structure. At the expense of smaller R f , the obtained EASA values of these structures are in the range of those of large surface area supported fuel cell catalysts. The active surface area of the Pt dendritic NPs was measured by electron tomography, and it was found that the potential cycling in the H adsorption/desorption and Pt oxidation/reduction region, which is generally performed to determine the EASA, leads to a significant reduction of that surface area due to a partial collapse of their dendritic and porous morphology. Interestingly, the extrapolation of the microscopic tomography results in macroscopic electrochemical parameters indicates that the surface properties measured by H UPD are comparable to the values measured on individual NPs by electron tomography after the degradation caused by the H UPD measurement. These results highlight that the combination of electrochemical and quantitative 3D surface analysis techniques is essential to provide insights into the surface properties, the electrochemical stability, and, hence, the applicability of these materials. Moreover, it indicates that care must be taken with widely used electrochemical methods of surface area determination, especially in the case of large surface area and possibly unstable nanostructures, since the measured surface can be strongly affected by the measurement itself.

Occupational Exposure to Cobalt and Tungsten in the Swedish Hard Metal Industry: Air Concentrations of Particle Mass, Number, and Surface Area

PubMed Central

Bryngelsson, Ing-Liss; Pettersson, Carin; Husby, Bente; Arvidsson, Helena; Westberg, Håkan

2016-01-01

Exposure to cobalt in the hard metal industry entails severe adverse health effects, including lung cancer and hard metal fibrosis. The main aim of this study was to determine exposure air concentration levels of cobalt and tungsten for risk assessment and dose–response analysis in our medical investigations in a Swedish hard metal plant. We also present mass-based, particle surface area, and particle number air concentrations from stationary sampling and investigate the possibility of using these data as proxies for exposure measures in our study. Personal exposure full-shift measurements were performed for inhalable and total dust, cobalt, and tungsten, including personal real-time continuous monitoring of dust. Stationary measurements of inhalable and total dust, PM2.5, and PM10 was also performed and cobalt and tungsten levels were determined, as were air concentration of particle number and particle surface area of fine particles. The personal exposure levels of inhalable dust were consistently low (AM 0.15mg m−3, range <0.023–3.0mg m−3) and below the present Swedish occupational exposure limit (OEL) of 10mg m−3. The cobalt levels were low as well (AM 0.0030mg m−3, range 0.000028–0.056mg m−3) and only 6% of the samples exceeded the Swedish OEL of 0.02mg m−3. For continuous personal monitoring of dust exposure, the peaks ranged from 0.001 to 83mg m−3 by work task. Stationary measurements showed lower average levels both for inhalable and total dust and cobalt. The particle number concentration of fine particles (AM 3000 p·cm−3) showed the highest levels at the departments of powder production, pressing and storage, and for the particle surface area concentrations (AM 7.6 µm2·cm−3) similar results were found. Correlating cobalt mass-based exposure measurements to cobalt stationary mass-based, particle area, and particle number concentrations by rank and department showed significant correlations for all measures except for particle number. Linear regression analysis of the same data showed statistically significant regression coefficients only for the mass-based aerosol measures. Similar results were seen for rank correlation in the stationary rig, and linear regression analysis implied significant correlation for mass-based and particle surface area measures. The mass-based air concentration levels of cobalt and tungsten in the hard metal plant in our study were low compared to Swedish OELs. Particle number and particle surface area concentrations were in the same order of magnitude as for other industrial settings. Regression analysis implied the use of stationary determined mass-based and particle surface area aerosol concentration as proxies for various exposure measures in our study. PMID:27143598

New Variance-Reducing Methods for the PSD Analysis of Large Optical Surfaces

NASA Technical Reports Server (NTRS)

Sidick, Erkin

2010-01-01

Edge data of a measured surface map of a circular optic result in large variance or "spectral leakage" behavior in the corresponding Power Spectral Density (PSD) data. In this paper we present two new, alternative methods for reducing such variance in the PSD data by replacing the zeros outside the circular area of a surface map by non-zero values either obtained from a PSD fit (method 1) or taken from the inside of the circular area (method 2).

Atmospheric structure favoring high sea surface temperatures in the western equatorial Pacific

NASA Astrophysics Data System (ADS)

Wirasatriya, Anindya; Kawamura, Hiroshi; Shimada, Teruhisa; Hosoda, Kohtaro

2016-10-01

We investigated the atmospheric processes over high sea surface temperature called Hot Event (HE) in the western equatorial Pacific from climatological analysis and a case study of the HE which began on 28 May 2003 (hereafter, HE030528). Climatological analysis shows that during the development stage of HE, solar radiation inside the HE area is higher than its climatology and wind speed is lower than the decay stage. During the decay stage, strong westerly wind often occurs inside HE area. The case study of HE030528 shows that the suppressed convection above high SST area resulted from the deep convection from the northern and southern areas outside HE. The suppressed convection created a band-shaped structure of low cloud cover along HE area increasing solar radiation during the development stage. Thus, the theory of "remote convection" was supported for the HE030528 formation mechanisms. The large sea level pressure gradient magnitude between the southern side of the terrain gap and the northern coast of the Solomon Islands, through which strong wind blew, indicated the role of land topography for the increase of wind speed during the decay of HE030528. Moreover, surface wind had an important role to influence the variability of solar radiation during the occurrence of HE030528 by controlling the water vapor supply in the upper troposphere through surface evaporation and surface convergence variation. Thus, surface wind was the key factor for HE030528 occurrence. The representativeness of HE030528 and the possible relation between HE and Madden-Julian Oscillation are also discussed.

Cooling effect of rivers on metropolitan Taipei using remote sensing.

PubMed

Chen, Yen-Chang; Tan, Chih-Hung; Wei, Chiang; Su, Zi-Wen

2014-01-23

This study applied remote sensing technology to analyze how rivers in the urban environment affect the surface temperature of their ambient areas. While surface meteorological stations can supply accurate data points in the city, remote sensing can provide such data in a two-dimensional (2-D) manner. The goal of this paper is to apply the remote sensing technique to further our understanding of the relationship between the surface temperature and rivers in urban areas. The 2-D surface temperature data was retrieved from Landsat-7 thermal infrared images, while data collected by Formosat-2 was used to categorize the land uses in the urban area. The land surface temperature distribution is simulated by a sigmoid function with nonlinear regression analysis. Combining the aforementioned data, the range of effect on the surface temperature from rivers can be derived. With the remote sensing data collected for the Taipei Metropolitan area, factors affecting the surface temperature were explored. It indicated that the effect on the developed area was less significant than on the ambient nature zone; moreover, the size of the buffer zone between the river and city, such as the wetlands or flood plain, was found to correlate with the affected distance of the river surface temperature.

Cooling Effect of Rivers on Metropolitan Taipei Using Remote Sensing

PubMed Central

Chen, Yen-Chang; Tan, Chih-Hung; Wei, Chiang; Su, Zi-Wen

2014-01-01

This study applied remote sensing technology to analyze how rivers in the urban environment affect the surface temperature of their ambient areas. While surface meteorological stations can supply accurate data points in the city, remote sensing can provide such data in a two-dimensional (2-D) manner. The goal of this paper is to apply the remote sensing technique to further our understanding of the relationship between the surface temperature and rivers in urban areas. The 2-D surface temperature data was retrieved from Landsat-7 thermal infrared images, while data collected by Formosat-2 was used to categorize the land uses in the urban area. The land surface temperature distribution is simulated by a sigmoid function with nonlinear regression analysis. Combining the aforementioned data, the range of effect on the surface temperature from rivers can be derived. With the remote sensing data collected for the Taipei Metropolitan area, factors affecting the surface temperature were explored. It indicated that the effect on the developed area was less significant than on the ambient nature zone; moreover, the size of the buffer zone between the river and city, such as the wetlands or flood plain, was found to correlate with the affected distance of the river surface temperature. PMID:24464232

Use of aerial photos and field reconnaissance to predict groundwater flow of a karst area in the Inner Bluegrass Region of Kentucky

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

Gremos, K.; Sendlein, L.V.A.

1993-03-01

Significant areas of the continental US (Kentucky included) are underlain by karstified limestone. In many of these areas agriculture is a leading business and a potential non-point source of pollution to the groundwater. A study is underway to assess the Best Management Practices (BMP) on a farm in north-central Woodford County in Kentucky. As part of the study, various computer-based decision models for integrated farm operation will be assessed. Because surface area and run off are integral parts of all of these models, diversion of surface run off through karst features such as sinkholes will modify predictions from these models.more » This study utilizes areal photographs to identify all sinkholes on the property and characterize their morphometric parameters such as length, width, depth, and area and distribution. Sink hole areas represent approximately 10 percent of the area and all but a few discharge within the basin monitored as part of the model. The bedrock geology and fractures of the area have been defined using fracture trace analysis and a rectified drainage linear analysis. Surface drainage patterns, spring distribution, and stream and spring discharge data have been collected. Dye tracing has identified groundwater basins whose catchment area is outside the boundaries of the study site.« less

Distributions of clay minerals in surface sediments of the middle Bay of Bengal: Source and transport pattern

NASA Astrophysics Data System (ADS)

Li, Jingrui; Liu, Shengfa; Shi, Xuefa; Feng, Xiuli; Fang, Xisheng; Cao, Peng; Sun, Xingquan; Wenxing, Ye; Khokiattiwong, Somkiat; Kornkanitnan, Narumol

2017-08-01

The clay mineral contents in 110 surface sediment samples collected from the middle of the Bay of Bengal were analyzed by X-ray diffraction (XRD) to investigate the provenance and transport patterns. The illite content was highest, followed by chlorite, kaolinite and then smectite, with average weight percent distributions of 52%, 22%, 14% and 12%, respectively. Illite and chlorite had similar distribution pattern, with higher contents in the northern and central areas and lower contents in the southern area, whereas smectite showed the opposite distribution pattern. Kaolinite show no obvious higher or lower areas and the southern ;belt; was one of the highest content areas. Based on the spatial distribution characteristics and cluster analysis results, the study area can be classified into two provinces. Province I covers the southwestern area and contains high concentrations of illite and smectite sediments. Province II covers most sites and is also characterized by high concentrations of illite, but the weight percent of smectite is only half of that of province I. According to a quantitative estimate using end-member clay minerals contents, the relative contributions from the Himalayan source and the Indian source are 63% and 37% on average, respectively. Integrative analysis indicates that the hydrodynamic environment in the study area, especially the turbidity and surface monsoonal circulation, plays an important role in the spatial distribution and dispersal of the clay fraction in the sediments. The sediments in province I are mainly from the Indian source transported by the East Indian Coastal Current (EICC) and the surface monsoon circulation with minor contributions from the Himalayan source while the sediments in province II are mainly from the Himalayan source transported by turbidity and surface monsoonal circulation with little contribution from Indian river materials.

Quantitative analysis of surface characteristics and morphology in Death Valley, California using AIRSAR data

NASA Technical Reports Server (NTRS)

Kierein-Young, K. S.; Kruse, F. A.; Lefkoff, A. B.

1992-01-01

The Jet Propulsion Laboratory Airborne Synthetic Aperture Radar (JPL-AIRSAR) is used to collect full polarimetric measurements at P-, L-, and C-bands. These data are analyzed using the radar analysis and visualization environment (RAVEN). The AIRSAR data are calibrated using in-scene corner reflectors to allow for quantitative analysis of the radar backscatter. RAVEN is used to extract surface characteristics. Inversion models are used to calculate quantitative surface roughness values and fractal dimensions. These values are used to generate synthetic surface plots that represent the small-scale surface structure of areas in Death Valley. These procedures are applied to a playa, smooth salt-pan, and alluvial fan surfaces in Death Valley. Field measurements of surface roughness are used to verify the accuracy.

LANDSAT inventory of surface-mined areas using extendible digital techniques

NASA Technical Reports Server (NTRS)

Anderson, A. T.; Schultz, D. T.; Buchman, N.

1975-01-01

Multispectral LANDSAT imagery was analyzed to provide a rapid and accurate means of identification, classification, and measurement of strip-mined surfaces in Western Maryland. Four band analysis allows distinction of a variety of strip-mine associated classes, but has limited extendibility. A method for surface area measurements of strip mines, which is both geographically and temporally extendible, has been developed using band-ratioed LANDSAT reflectance data. The accuracy of area measurement by this method, averaged over three LANDSAT scenes taken between September 1972 and July 1974, is greater than 93%. Total affected acreage of large (50 hectare/124 acre) mines can be measured to within 1.0%.

Soil water erosion processes in mountain forest catchment - analysis by using terrestrial laser scanning

NASA Astrophysics Data System (ADS)

Dąbek, Paweł; Żmuda, Romuald; Szczepański, Jakub; Ćmielewski, Bartłomiej; Patrzałek, Ciechosław

2013-04-01

The paper presents the results of the analysis of the water erosion processes of soil occurring in forestry mountain catchment area in the region of West Sudetes Mountain in Poland. The research was carried out within the experimental area of skid trails (operational trails), which were used to the end of 2010 in obtaining wood and its mechanical transport to the place of storage. As a consequence of forestry works that were carried out it was changing the natural structure of ground and its surface on the wooded slopes, which, combined with the favorable hydro-meteorological conditions contributed to the intensification of the water erosion processes of soil on surface of trails. For the implementation of the research project of the analysis of water erosion processes in the forestry catchment area innovative was used terrestrial laser scanning. Using terrestrial laser scanning has enabled the analysis of the dynamics of erosion processes both in time, as well as in spatial and quantitative terms. Scanning was performed at a resolution of 4 mm, resulting in 62 500 points per 1 square meter. After filtering the data were interpolated to other resolution of 1 cm, which can identify even the smallest linear and surface effects of erosion. While installed on the experimental area, along the skid trails, anti-erosion barriers in order to reduce transport eroded material and allow its accumulation. Allowed to precisely determine the location of areas of accumulation, the rate and amount of accumulated material. The result of the analyses that was carried out is identification areas of denudation of the eroded material, and also determine the intensity of the erosion processes and their quantitative analysis. The long-term researches on hydrological conditions and forest complexes functioning show that forest effectively stores water, limits linear and surface flow and delays water outflow from a catchment. Carried out a research project using the terrestrial laser scanning shows that anthropogenic activities in the form of forest management and their effects in the form of dense network of forest roads and skid trails and obtaining wood diminish correct functioning of a forest or even increase the phenomenon of erosion. Submit the results of the analysis consider the problem of dynamics and intensity of erosion processes in mountain areas, and show the effectiveness of the methodology of research.

The Urban Heat Island Impact in Consideration of Spatial Pattern of Urban Landscape and Structure

NASA Astrophysics Data System (ADS)

Kim, J.; Lee, D. K.; Jeong, W.; Sung, S.; Park, J.

2015-12-01

Preceding study has established a clear relationship between land surface temperature and area of land covers. However, only few studies have specifically examined the effects of spatial patterns of land covers and urban structure. To examine how much the local climate is affected by the spatial pattern in highly urbanized city, we investigated the correlation between land surface temperature and spatial patterns of land covers. In the analysis of correlation, we categorized urban structure to four different land uses: Apartment residential area, low rise residential area, industrial area and central business district. Through this study, we aims to examine the types of residential structure and land cover pattern for reducing urban heat island and sustainable development. Based on land surface temperature, we investigated the phenomenon of urban heat island through using the data of remote sensing. This study focused on Daegu in Korea. This city, one of the hottest city in Korea has basin form. We used high-resolution land cover data and land surface temperature by using Landsat8 satellite image to examine 100 randomly selected sample sites of 884.15km2 (1)In each land use, we quantified several landscape-levels and class-level landscape metrics for the sample study sites. (2)In addition, we measured the land surface temperature in 3 year hot summer seasons (July to September). Then, we investigated the pattern of land surface temperature for each land use through Ecognition package. (3)We deducted the Pearson correlation coefficients between land surface temperature and each landscape metrics. (4)We analyzed the variance among the four land uses. (5)Using linear regression, we determined land surface temperature model for each land use. (6)Through this analysis, we aims to examine the best pattern of land cover and artificial structure for reducing urban heat island effect in highly urbanized city. The results of linear regression showed that proportional land cover of grass, tree, water and impervious surfaces well explained the temperature in apartment residential areas. In contrast, the changes in the pattern of water, grass, tree and impervious surfaces were the best to determine the temperature in low rise residential area, central business district and industrial area.

The influence of Y-TZP surface treatment on topography and ceramic/resin cement interfacial fracture toughness.

PubMed

Paes, P N G; Bastian, F L; Jardim, P M

2017-09-01

Consider the efficacy of glass infiltration etching (SIE) treatment as a procedure to modify the zirconia surface resulting in higher interfacial fracture toughness. Y-TZP was subjected to 5 different surface treatments conditions consisting of no treatment (G1), SIE followed by hydrofluoric acid treatment (G2), heat treated at 750°C (G3), hydrofluoric acid treated (G4) and airborne-particle abrasion with alumina particles (G5). The effect of surface treatment on roughness was evaluated by Atomic Force Microscopy providing three different parameters: R a , R sk and surface area variation. The ceramic/resin cement interface was analyzed by Fracture Mechanics K I test with failure mode determined by fractographic analysis. Weibull's analysis was also performed to evaluate the structural integrity of the adhesion zone. G2 and G4 specimens showed very similar, and high R a values but different surface area variation (33% for G2 and 13% for G4) and they presented the highest fracture toughness (K IC ). Weibull's analysis showed G2 (SIE) tendency to exhibit higher K IC values than the other groups but with more data scatter and a higher early failure probability than G4 specimens. Selective glass infiltration etching surface treatment was effective in modifying the zirconia surface roughness, increasing the bonding area and hence the mechanical imbrications at the zirconia/resin cement interface resulting in higher fracture toughness (K IC ) values with higher K IC values obtained when failure probability above 20% was expected (Weibull's distribution) among all the experimental groups. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

[The design and implementation of the web typical surface object spectral information system in arid areas based on .NET and SuperMap].

PubMed

Xia, Jun; Tashpolat, Tiyip; Zhang, Fei; Ji, Hong-jiang

2011-07-01

The characteristic of object spectrum is not only the base of the quantification analysis of remote sensing, but also the main content of the basic research of remote sensing. The typical surface object spectral database in arid areas oasis is of great significance for applied research on remote sensing in soil salinization. In the present paper, the authors took the Ugan-Kuqa River Delta Oasis as an example, unified .NET and the SuperMap platform with SQL Server database stored data, used the B/S pattern and the C# language to design and develop the typical surface object spectral information system, and established the typical surface object spectral database according to the characteristics of arid areas oasis. The system implemented the classified storage and the management of typical surface object spectral information and the related attribute data of the study areas; this system also implemented visualized two-way query between the maps and attribute data, the drawings of the surface object spectral response curves and the processing of the derivative spectral data and its drawings. In addition, the system initially possessed a simple spectral data mining and analysis capabilities, and this advantage provided an efficient, reliable and convenient data management and application platform for the Ugan-Kuqa River Delta Oasis's follow-up study in soil salinization. Finally, It's easy to maintain, convinient for secondary development and practically operating in good condition.

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.; Trost, Jared J.; Erickson, Melinda L.

2016-10-19

OverviewThis study assessed lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes applying three approaches: statistical analysis, field study, and groundwater-flow modeling.  Statistical analyses of lake levels were completed to assess the effect of physical setting and climate on lake-level fluctuations of selected lakes. A field study of groundwater and surface-water interactions in selected lakes was completed to (1) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (2) estimate general ages for waters extracted from the wells, and (3) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake.  Groundwater flow was simulated using a steady-state, groundwater-flow model to assess regional groundwater and surface-water exchanges and the effects of groundwater withdrawals, climate, and other factors on water levels of northeast Twin Cities Metropolitan Area lakes.

Why mushrooms form gills: efficiency of the lamellate morphology.

PubMed

Fischer, Mark W F; Money, Nicholas P

2010-01-01

Gilled mushrooms are produced by multiple orders within the Agaricomycetes. Some species form a single array of unbranched radial gills beneath their caps, many others produce multiple files of lamellulae between the primary gills, and branched gills are also common. In this largely theoretical study we modeled the effects of different gill arrangements on the total surface area for spore production. Relative to spore production over a flat surface, gills achieve a maximum 20-fold increase in surface area. The branching of gills produces the same increase in surface area as the formation of free-standing lamellulae (short gills). The addition of lamellulae between every second gill would offer a slightly greater increase in surface area in comparison to the addition of lamellulae between every pair of opposing gills, but this morphology does not appear in nature. Analysis of photographs of mushrooms demonstrates an excellent match between natural gill arrangements and configurations predicted by our model. Copyright © 2009 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Electro and Magneto-Electropolished Surface Micro-Patterning on Binary and Ternary Nitinol

PubMed Central

Munroe, Norman; McGoron, Anthony

2012-01-01

In this study, an Atomic Force Microscopy (AFM) roughness analysis was performed on non-commercial Nitinol alloys with Electropolished (EP) and Magneto-Electropolished (MEP) surface treatments and commercially available stents by measuring Root-Mean-Square (RMS), Average Roughness (Ra), and Surface Area (SA) values at various dimensional areas on the alloy surfaces, ranging from (800 × 800 nm) to (115 × 115μm), and (800 × 800 nm) to (40 × 40 μm) on the commercial stents. Results showed that NiTi-Ta 10 wt% with an EP surface treatment yielded the highest overall roughness, while the NiTi-Cu 10 wt% alloy had the lowest roughness when analyzed over (115 × 115 μm). Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analysis revealed unique surface morphologies for surface treated alloys, as well as an aggregation of ternary elements Cr and Cu at grain boundaries in MEP and EP surface treated alloys, and non-surface treated alloys. Such surface micro-patterning on ternary Nitinol alloys could increase cellular adhesion and accelerate surface endothelialization of endovascular stents, thus reducing the likelihood of in-stent restenosis and provide insight into hemodynamic flow regimes and the corrosion behavior of an implantable device influenced from such surface micro-patterns. PMID:22754200

Geometry program for aerodynamic lifting surface theory

NASA Technical Reports Server (NTRS)

Medan, R. T.

1973-01-01

A computer program that provides the geometry and boundary conditions appropriate for an analysis of a lifting, thin wing with control surfaces in linearized, subsonic, steady flow is presented. The kernel function method lifting surface theory is applied. The data which is generated by the program is stored on disk files or tapes for later use by programs which calculate an influence matrix, plot the wing planform, and evaluate the loads on the wing. In addition to processing data for subsequent use in a lifting surface analysis, the program is useful for computing area and mean geometric chords of the wing and control surfaces.

Characterization of technical surfaces by structure function analysis

NASA Astrophysics Data System (ADS)

Kalms, Michael; Kreis, Thomas; Bergmann, Ralf B.

2018-03-01

The structure function is a tool for characterizing technical surfaces that exhibits a number of advantages over Fourierbased analysis methods. So it is optimally suited for analyzing the height distributions of surfaces measured by full-field non-contacting methods. The structure function is thus a useful method to extract global or local criteria like e. g. periodicities, waviness, lay, or roughness to analyze and evaluate technical surfaces. After the definition of line- and area-structure function and offering effective procedures for their calculation this paper presents examples using simulated and measured data of technical surfaces including aircraft parts.

Lunar mission safety and rescue: Escape/rescue analysis and plan

NASA Technical Reports Server (NTRS)

1971-01-01

The results are presented of the technical analysis of escape/rescue/survival situations, crew survival techniques, alternate escape/rescue approaches and vehicles, and the advantages and disadvantages of each for advanced lunar exploration. Candidate escape/rescue guidelines are proposed and elements of a rescue plan developed. The areas of discussions include the following: lunar arrival/departure operations, lunar orbiter operations, lunar surface operations, lunar surface base escape/rescue analysis, lander tug location operations, portable airlock, emergency pressure suit, and the effects of no orbiting lunar station, no lunar surface base, and no foreign lunar orbit/surface operations on the escape/rescue plan.

Hydrology, description of computer models, and evaluation of selected water-management alternatives in the San Bernardino area, California

USGS Publications Warehouse

Danskin, Wesley R.; McPherson, Kelly R.; Woolfenden, Linda R.

2006-01-01

The San Bernardino area of southern California has complex water-management issues. As an aid to local water managers, this report provides an integrated analysis of the surface-water and ground-water systems, documents ground-water flow and constrained optimization models, and provides seven examples using the models to better understand and manage water resources of the area. As an aid to investigators and water managers in other areas, this report provides an expanded description of constrained optimization techniques and how to use them to better understand the local hydrogeology and to evaluate inter-related water-management problems. In this report, the hydrology of the San Bernardino area, defined as the Bunker Hill and Lytle Creek basins, is described and quantified for calendar years 1945-98. The major components of the surface-water system are identified, and a routing diagram of flow through these components is provided. Annual surface-water inflow and outflow for the area are tabulated using gaged measurements and estimated values derived from linear-regression equations. Average inflow for the 54-year period (1945-98) was 146,452 acre-feet per year; average outflow was 67,931 acre-feet per year. The probability of exceedance for annual surface-water inflow is calculated using a Log Pearson Type III analysis. Cumulative surface-water inflow and outflow and ground-water-level measurements indicate that the relation between the surface-water system and the ground-water system changed in about 1951, in about 1979, and again in about 1992. Higher ground-water levels prior to 1951 and between 1979 and 1992 induced ground-water discharge to Warm Creek. This discharge was quantified using streamflow measurements and can be estimated for other time periods using ground-water levels from a monitoring well (1S/4W-3Q1) and a logarithmic-regression equation. Annual wastewater discharge from the area is tabulated for the major sewage and power-plant facilities. More...

Exploring the Influence of Impervious Surface Density and Shape on Urban Heat Islands in the Northeast USA Using MODIS and Landsat

NASA Technical Reports Server (NTRS)

Zhang, Ping; Imhoff, Marc L.; Bounoua, Lahouri; Wolfe, Robert E.

2011-01-01

Impervious surface area (ISA) from the National Land Cover Database (NLCD) 2001 and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) signature and its relationship to settlement size and shape, development intensity distribution, and land cover composition for 42 urban settlements embedded in forest biomes in the Northeastern United States. Development intensity zones, based on percent ISA, are defined for each urban area emanating outward from the urban core to nearby rural areas and are used to stratify land surface temperature. The stratification is further constrained by biome type and elevation to insure objective intercomparisons between urban zones within an urban settlement and between settlements. Stratification based on ISA allows the definition of hierarchically ordered urban zones that are consistent across urban settlements and scales. In addition to the surrounding ecological context, we find that the settlement size and shape as well as the development intensity distribution significantly influence the amplitude of summer daytime UHI. Within the Northeastern US temperate broadleaf mixed forest, UHI magnitude is positively related to the logarithm of the urban area size. Our study indicates that for similar urban area sizes, the development intensity distribution is one of the major drivers of UHI. In addition to urban area size and development intensity distribution, this analysis shows that both the shape of the urban area and the land cover composition in the surrounding rural area play an important role in modulating the UHI magnitude in different urban settlements. Our results indicate that remotely sensed urban area size and shape as well as the development intensity distribution influence UHI amplitude across regional scales.

Regeneration of Waste Edible Oil by the Use of Virgin and Calcined Magnesium Hydroxide as Adsorbents.

PubMed

Ogata, Fumihiko; Kawasaki, Naohito

2016-01-01

In this study, we prepared virgin (S, L) and calcined (S-380, S-1000, L-380, L-1000) magnesium hydroxide for regeneration of waste edible oil. Deterioration of soybean oil, rapeseed oil, and olive oil was achieved by heat and aeration treatment. The properties of the different adsorbents were investigated using specific surface area measurements, scanning electron microscopy, X-ray diffraction analysis, thermogravimetric-differential thermal analysis, and surface pH measurement. Moreover, the relationship between the changes in acid value (AV) and carbonyl value (CV) and the adsorbent properties were evaluated. The specific surface areas of S-380 and L-380 were greater than that of other adsorbents. In addition, the XRD results show that S-380 and L-380 contain both magnesium hydroxide and magnesium oxide structures. The decreases in AV and CV using S-380 and L-380 were greater than achieved using other adsorbents. The correlation coefficients between the decrease in AV and CV and specific surface area were 0.947 for soybean oil, 0.649 for rapeseed oil, and 0.773 for olive oil, respectively. The results obtained in this study suggest that a physical property of the adsorbent, namely specific surface area, was primarily responsible for the observed decreases in AV and CV. Overall, the results suggest that S-380 and L-380 are useful for the regeneration of waste edible oil.

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

fMRI evidence for areas that process surface gloss in the human visual cortex

PubMed Central

Sun, Hua-Chun; Ban, Hiroshi; Di Luca, Massimiliano; Welchman, Andrew E.

2015-01-01

Surface gloss is an important cue to the material properties of objects. Recent progress in the study of macaque’s brain has increased our understating of the areas involved in processing information about gloss, however the homologies with the human brain are not yet fully understood. Here we used human functional magnetic resonance imaging (fMRI) measurements to localize brain areas preferentially responding to glossy objects. We measured cortical activity for thirty-two rendered three-dimensional objects that had either Lambertian or specular surface properties. To control for differences in image structure, we overlaid a grid on the images and scrambled its cells. We found activations related to gloss in the posterior fusiform sulcus (pFs) and in area V3B/KO. Subsequent analysis with Granger causality mapping indicated that V3B/KO processes gloss information differently than pFs. Our results identify a small network of mid-level visual areas whose activity may be important in supporting the perception of surface gloss. PMID:25490434

Surface water polycyclic aromatic hydrocarbons (PAH) in urban areas of Nanjing, China.

PubMed

Wang, Chunhui; Zhou, Shenglu; Wu, Shaohua; Song, Jing; Shi, Yaxing; Li, Baojie; Chen, Hao

2017-10-01

The concentration, sources and environmental risks of polycyclic aromatic hydrocarbons (PAHs) in surface water in urban areas of Nanjing were investigated. The range of ∑ 16 PAHs concentration is between 4,076 and 29,455 ng/L, with a mean of 17,212 ng/L. The composition of PAHs indicated that 2- and 3-ring PAHs have the highest proportion in all PAHs, while the 5- and 6-ring PAHs were the least in proportion. By diagnostic ratio analysis, combustion and petroleum were a mixture input that contributed to the water PAH in urban areas of Nanjing. Positive matrix factorization quantitatively identified four factors, including coke oven, coal combustion, oil source, and vehicle emission, as the main sources. Toxic equivalency factors of BaP (BaP eq ) evaluate the environmental risks of PAHs and indicate the PAH concentration in surface water in urban areas of Nanjing had been polluted and might cause potential environmental risks. Therefore, the PAH contamination in surface water in urban areas of Nanjing should draw considerable attention.

Synthesis of mesoporous cerium compound for CO2 capture

NASA Astrophysics Data System (ADS)

Liu, Guiqing; Tatsuda, Kou; Yoneyama, Yoshiharu; Tsubaki, Noritatsu

2017-11-01

A mesoporous adsorbent was simply synthesized by adding alkaline substances to cerium(III) nitric hydrate. The surface characteristics of the synthesized cerium compound were determined with BET, XRD and TEM analysis. It was found that although the specific surface areas of the synthesized cerium compounds were among about 120-200m2 per gram (BET area) which were smaller than the common used zeolite 13X (BET area 743 m2/g) and activated carbon (BET area 1079 m2/g), but the cerium compounds had excellent performances for CO2 adsorption as well as the CO2 desorption.

Ability of barrier coat S-PRG coating to arrest artificial enamel lesions in primary teeth.

PubMed

Hosoya, Yumiko; Ando, Susumu; Otani, Hideji; Yukinari, Tetsuhiro; Miyazaki, Masashi; Garcia-Godoy, Franklin

2013-10-01

To evaluate the effects of a surface pre-reacted glass-ionomer (S-PRG) filled coating material to arrest artificial enamel lesions in primary teeth. Buccal and lingual enamel was demineralized in 0.1 M lactic acid buffer solution (pH 4.75) for 5 days and then divided in the PRG-applied and non-PRG areas. Proximal surfaces were used as a control area without demineralization and coating application. Teeth were divided into three groups (n = 4) according to the 1-week immersion in different solutions: Group 1 (distilled water), Group 2 (demineralizing solution) and Group 3 (artificial saliva). Hardness and Young's modulus by nano-indentation test, and elemental contents and ultrastructure by SEM/EDX analysis were obtained. Data were statistically analyzed using ANOVA and Fisher's PLSD at alpha = 0.05. Only for the non-PRG area in Group 1, the hardness and Young's modulus of the demineralized surface enamel were significantly lower than those of the enamel 30-60 microm beneath the surface. Demineralized enamel of non-PRG and PRG-applied areas showed similar SEM views. Only for the non-PRG area in Group 2 and control area in Group 3, the Ca/P of the surface enamel was significantly higher than that of the enamel 5-10 microm beneath the surface. There was no significant difference of the Ca/P among the measuring points from the surface to 10 microm depth of enamel for the PRG applied area in Group 2.

Understanding spatial-temporal urban expansion pattern (1990-2009) using impervious surface data and landscape indexes: a case study in Guangzhou (China)

NASA Astrophysics Data System (ADS)

Fan, Fenglei; Fan, Wei

2014-01-01

A new viewpoint for understanding the urban expansion using impervious surface information, which is obtained using remote sensing imagery is presented. The purpose of this study is to understand and describe the urban expansion pattern with the view of impervious surfaces instead of the conventional view of land use/land cover. Six years' worth of impervious surface data (1990-2009) of Guangzhou are extracted via linear spectral unmixing analysis methods and spatial and temporal characteristics are discussed in detail. The area, density, and gravity centers changes of the impervious surfaces are analyzed to explain internal/external urban expansion. Meanwhile, five landscape indexes, such as patch density, edge density, mean patch size, area-weighted, and fragmentation index, are utilized to describe landscape changes of Guangzhou in past 20 years, which are influenced deeply by the impervious surface expansion. In order to detail landscape changes, two transects corresponding to the two urban expansion directions are designed and five landscape metrics in these two transects are reported. Conclusions can be drawn and shown as following: (1) temporally, the area of impervious surfaces increases from 12,998 to 59,911 ha from 1990 to 2009. The amount of impervious surface varies in different periods. The annual growth rates of impervious surface area during 1990-1995, 1995-1998, and 1998-2000 are 10.16%, 11.61%, and 10.78%, respectively; (2) annual growth rates decrease from 10.78% (1998-2000) to 5.67% (2000-2003). Nevertheless, from 2003-2009, the annual growth rate has a slight increase compared to a former period. The rate is 5.91% (3) spatially, gravity centers of medium and high percentage impervious surfaces migrate slightly; and (4) according to the gradient analysis in the two transects, it can be observed that the high percentage of impervious surface increases gradually in new city districts (from west to east and from south to north).

Land Surface Properties near Terra Nova Bay, East Antarctica, Analyzed by Time-series Height, Coherence and Amplitude Maps Derived from COSMO-SkyMed One-day Tandem Pairs

NASA Astrophysics Data System (ADS)

Ji, Y.; Han, H.; Lee, H.

2014-12-01

Analysis of the surface properties of Antarctica is very important to study the change of environment and climate in the polar region. Synthetic aperture radar (SAR) has been widely used to study Antarctic surface properties because it is independent of sun altitude and atmospheric conditions. Interferometric SAR (InSAR) observes surface topography and deformation, by calculating the phase differences between two or more SAR images obtained over same area. InSAR technique can be used for height mapping in stable areas with a few meter accuracy. However, the InSAR-derived height map can have errors if the phase differences due to surface deformation or change of the scattering center by microwave penetration into snow are misinterpreted as the elevation. In this study, we generated the height maps around Terra Nova Bay in East Antarctica from 13 COSMO-SkyMed one-day tandem InSAR pairs obtained from December 2010 to January 2012. By analyzing the height maps averaged over the 13 interferograms and its standard deviation (STD) map, we could classify the surface types into glacier, mountains and basin areas covered with snow. The mountain areas showed very small STD because its surface property is unchanged with time, except for the small STD values caused by the errors from the unwrapping processing, satellite orbit or atmospheric phase distortion. Over the basin areas, however, the STD of the height was much larger than the mountain area due to the variation of scattering center either from the change in surface property such as snowfall and sublimation or by the surface displacement of snow mass that are too slow. A year-long constant motion of such slow-creeping snow body was positively identified by its linear relationship between the misinterpreted elevation and the baseline perpendicular component of InSAR pair. Analysis of time-series coherence maps and amplitude maps have also contributed to clarify the surface properties and its changes due to various environmental factors such as snow fall, wind, sublimation, and the freezing-thawing processes in this Antarctic land surface. Acknowledgement - This research was supported by National Research Foundation of Korea through NRF-2013R1A1A2008062 and NRF-2013M1A3A3A02041853.

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.

Automated mapping of impervious surfaces in urban and suburban areas: Linear spectral unmixing of high spatial resolution imagery

NASA Astrophysics Data System (ADS)

Yang, Jian; He, Yuhong

2017-02-01

Quantifying impervious surfaces in urban and suburban areas is a key step toward a sustainable urban planning and management strategy. With the availability of fine-scale remote sensing imagery, automated mapping of impervious surfaces has attracted growing attention. However, the vast majority of existing studies have selected pixel-based and object-based methods for impervious surface mapping, with few adopting sub-pixel analysis of high spatial resolution imagery. This research makes use of a vegetation-bright impervious-dark impervious linear spectral mixture model to characterize urban and suburban surface components. A WorldView-3 image acquired on May 9th, 2015 is analyzed for its potential in automated unmixing of meaningful surface materials for two urban subsets and one suburban subset in Toronto, ON, Canada. Given the wide distribution of shadows in urban areas, the linear spectral unmixing is implemented in non-shadowed and shadowed areas separately for the two urban subsets. The results indicate that the accuracy of impervious surface mapping in suburban areas reaches up to 86.99%, much higher than the accuracies in urban areas (80.03% and 79.67%). Despite its merits in mapping accuracy and automation, the application of our proposed vegetation-bright impervious-dark impervious model to map impervious surfaces is limited due to the absence of soil component. To further extend the operational transferability of our proposed method, especially for the areas where plenty of bare soils exist during urbanization or reclamation, it is still of great necessity to mask out bare soils by automated classification prior to the implementation of linear spectral unmixing.

Testing of stack-unit/aquifer sensitivity analysis using contaminant plume distribution in the subsurface of Savannah River Site, South Carolina, USA

USGS Publications Warehouse

Rine, J.M.; Shafer, J.M.; Covington, E.; Berg, R.C.

2006-01-01

Published information on the correlation and field-testing of the technique of stack-unit/aquifer sensitivity mapping with documented subsurface contaminant plumes is rare. The inherent characteristic of stack-unit mapping, which makes it a superior technique to other analyses that amalgamate data, is the ability to deconstruct the sensitivity analysis on a unit-by-unit basis. An aquifer sensitivity map, delineating the relative sensitivity of the Crouch Branch aquifer of the Administrative/Manufacturing Area (A/M) at the Savannah River Site (SRS) in South Carolina, USA, incorporates six hydrostratigraphic units, surface soil units, and relevant hydrologic data. When this sensitivity map is compared with the distribution of the contaminant tetrachloroethylene (PCE), PCE is present within the Crouch Branch aquifer within an area classified as highly sensitive, even though the PCE was primarily released on the ground surface within areas classified with low aquifer sensitivity. This phenomenon is explained through analysis of the aquifer sensitivity map, the groundwater potentiometric surface maps, and the plume distributions within the area on a unit-by- unit basis. The results of this correlation show how the paths of the PCE plume are influenced by both the geology and the groundwater flow. ?? Springer-Verlag 2006.

Disaster risk management in prospect mining area Blitar district, East Java, using microtremor analysis and ANP (analytical network processing) approach

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

Parwatiningtyas, Diyan, E-mail: diane.tyas@gmail.com, E-mail: erlinunindra@gmail.com; Ambarsari, Erlin Windia, E-mail: diane.tyas@gmail.com, E-mail: erlinunindra@gmail.com; Marlina, Dwi, E-mail: diane.tyas@gmail.com, E-mail: erlinunindra@gmail.com

Indonesia has a wealth of natural assets is so large to be managed and utilized, either from its own local government and local communities, especially in the mining sector. However, mining activities can change the state of the surface layer of the earth that have a high impact disaster risk. This could threaten the safety and disrupt human life, environmental damage, loss of property, and the psychological impact, sulking to the rule of law no 24 of 2007. That's why we strive to manage and minimize the risk of mine disasters in the region, how to use the method ofmore » calculation of Amplification Factor (AF) from the analysis based microtremor sulking Kanai and Nakamura, and decision systems were tested by analysis of ANP. Based on the amplification factor and Analytical Network Processing (ANP) obtained, some points showed instability in the surface layer of a mining area include the site of the TP-7, TP-8, TP-9, TP-10, (Birowo2). If in terms of structure, location indicated unstable due to have a sloping surface layer, resulting in the occurrence of landslides and earthquake risk is high. In the meantime, other areas of the mine site can be said to be a stable area.« less

Disaster risk management in prospect mining area Blitar district, East Java, using microtremor analysis and ANP (analytical network processing) approach

NASA Astrophysics Data System (ADS)

Parwatiningtyas, Diyan; Ambarsari, Erlin Windia; Marlina, Dwi; Wiratomo, Yogi

2014-03-01

Indonesia has a wealth of natural assets is so large to be managed and utilized, either from its own local government and local communities, especially in the mining sector. However, mining activities can change the state of the surface layer of the earth that have a high impact disaster risk. This could threaten the safety and disrupt human life, environmental damage, loss of property, and the psychological impact, sulking to the rule of law no 24 of 2007. That's why we strive to manage and minimize the risk of mine disasters in the region, how to use the method of calculation of Amplification Factor (AF) from the analysis based microtremor sulking Kanai and Nakamura, and decision systems were tested by analysis of ANP. Based on the amplification factor and Analytical Network Processing (ANP) obtained, some points showed instability in the surface layer of a mining area include the site of the TP-7, TP-8, TP-9, TP-10, (Birowo2). If in terms of structure, location indicated unstable due to have a sloping surface layer, resulting in the occurrence of landslides and earthquake risk is high. In the meantime, other areas of the mine site can be said to be a stable area.

An Evaluation of Sea Surface Temperature as Measured by the Nimbus 1 High Resolution Infrared Radiometer

NASA Technical Reports Server (NTRS)

Allison, Lewis J.; Kennedy, James S.

1967-01-01

An analysis of Nimbus I HRIR data over various parts of the world indicated limited success in deriving sea surface temperatures to within 3 to 6 K of aircraft radiation measurements (8- 13 microns) and synoptic-climatological ship sea surface temperature data. The areas studied included the east, west and Gulf coasts of the United States, West Greenland, Nova Scotia, southern Japan, the eastern Mediterranean Sea, Caspian Sea, Persian Gulf, and the Indian Ocean. At night, thin clouds which may fill the radiometer's field of view make it difficult to interpret the absolute values of derived sea surface temperature. During the daytime, the HRIR data is unusable for oceanographic temperature analysis because the contamination by reflected solar radiation mixes with the emitted radiation. Future satellite instrumentation, consisting of a HFUR radiometer (10-11 microns) when used in conjunction with television. data, will delineate cloud free ocean areas and permit the daily derivation of sea surface temperatures from approximately 10 to 30 Percent of the world's oceanic regions.

Surface characterization and chemical analysis of bamboo substrates pretreated by alkali hydrogen peroxide.

PubMed

Song, Xueping; Jiang, Yan; Rong, Xianjian; Wei, Wei; Wang, Shuangfei; Nie, Shuangxi

2016-09-01

The surface characterization and chemical analysis of bamboo substrates by alkali hydrogen peroxide pretreatment (AHPP) were investigated in this study. The results tended to manifest that AHPP prior to enzymatic and chemical treatment was potential for improving accessibility and reactivity of bamboo substrates. The inorganic components, organic solvent extractives and acid-soluble lignin were effectively removed by AHPP. X-ray photoelectron spectroscopy (XPS) analysis indicated that the surface of bamboo chips had less lignin but more carbohydrate after pre-treatment. Fiber surfaces became etched and collapsed, and more pores and debris on the substrate surface were observed with Scanning Electron Microscopy (SEM). Brenauer-Emmett-Teller (BET) results showed that both of pore volume and surface area were increased after AHPP. Although XRD analysis showed that AHPP led to relatively higher crystallinity, pre-extraction could overall enhance the accessibility of enzymes and chemicals into the bamboo structure. Copyright © 2016. Published by Elsevier Ltd.

Subsurface structure imaging of the Sembalun-Propok area, West Nusa Tenggara, Indonesia by using the audio-frequency magnetotelluric data

NASA Astrophysics Data System (ADS)

Febriani, F.; Widarto, D. S.; Gaffar, E.; Nasution, A.; Grandis, H.

2017-07-01

We have investigated the subsurface structure of the Sembalun-Propok Area, West Nusa Tenggara, by using the audio-frequency magnetotelluric (AMT) method. This area is one of the geothermal prospect areas in eastern Indonesia. There are 38 AMT observation points, which were deployed along three profiles. We applied the phase tensor analysis on all observation points to determine both the dimensionality of and the regional strike of the study area. The results of the phase tensor analysis show that the study area can be assumed as 2-D and the regional strike of the study area is about N330°E. Then, after rotating the impedance tensor data to the regional strike, we carried out the 2-D inversion modeling to know more detail the subsurface structure of the study area. The results of the 2-D MT inversion are consistent with the geology of the study area. The near surface along all profiles is dominated by the higher resistivity layer (> 500 Ωm). It is highly associated with the surface geology of the study area which is characterized by the volcanic rock and mostly consist of andesitic to dacitic rocks of a calc-alkaline suite. Below the resistive layer at the near surface, the modelings show the layer which has the lower-moderate resistivity layer. It is possibly a cap rock layer of geothermal system of the Sembalun-Propok area. Lastly, the third layer is the very conductive layer and possibly associated with the presence of thermal fluids in the study area.

Estimating regional evapotranspiration from remotely sensed data by surface energy balance models

NASA Technical Reports Server (NTRS)

Asrar, Ghassem; Kanemasu, Edward; Myneni, R. B.; Lapitan, R. L.; Harris, T. R.; Killeen, J. M.; Cooper, D. I.; Hwang, C.

1987-01-01

Spatial and temporal variations of surface radiative temperatures of the burned and unburned areas of the Konza tallgrass prairie were studied. The role of management practices, topographic conditions and the uncertainties associated with in situ or airborne surface temperature measurements were assessed. Evaluation of diurnal and seasonal spectral characteristics of the burned and unburned areas of the prairie was also made. This was accomplished based on the analysis of measured spectral reflectance of the grass canopies under field conditions, and modelling their spectral behavior using a one dimensional radiative transfer model.

High-fidelity large area nano-patterning of silicon with femtosecond light sheet

NASA Astrophysics Data System (ADS)

Sidhu, Mehra S.; Munjal, Pooja; Singh, Kamal P.

2018-01-01

We employ a femtosecond light sheet generated by a cylindrical lens to rapidly produce high-fidelity nano-structures over large area on silicon surface. The Fourier analysis of electron microscopy images of the laser-induced surface structures reveals sharp peaks indicating good homogeneity. We observed an emergence of second-order spatial periodicity on increasing the scan speed. Our reliable approach may rapidly nano-pattern curved solid surfaces and tiny objects for diverse potential applications in optical devices, structural coloring, plasmonic substrates and in high-harmonic generation.

Correlating Humidity-Dependent Ionically Conductive Surface Area with Transport Phenomena in Proton-Exchange Membranes

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

He, Qinggang; Kusoglu, Ahmet; Lucas, Ivan T.

2011-08-01

The objective of this effort was to correlate the local surface ionic conductance of a Nafion? 212 proton-exchange membrane with its bulk and interfacial transport properties as a function of water content. Both macroscopic and microscopic proton conductivities were investigated at different relative humidity levels, using electrochemical impedance spectroscopy and current-sensing atomic force microscopy (CSAFM). We were able to identify small ion-conducting domains that grew with humidity at the surface of the membrane. Numerical analysis of the surface ionic conductance images recorded at various relative humidity levels helped determine the fractional area of ion-conducting active sites. A simple square-root relationshipmore » between the fractional conducting area and observed interfacial mass-transport resistance was established. Furthermore, the relationship between the bulk ionic conductivity and surface ionic conductance pattern of the Nafion? membrane was examined.« less

Subsidence Induced Faulting Hazard risk maps in Mexico City and Morelia, central Mexico

NASA Astrophysics Data System (ADS)

Cabral-Cano, E.; Solano-Rojas, D.; Hernández-Espriu, J.; Cigna, F.; Wdowinski, S.; Osmanoglu, B.; Falorni, G.; Bohane, A.; Colombo, D.

2012-12-01

Subsidence and surface faulting have affected urban areas in Central Mexico for decades and the process has intensified as a consequence of urban sprawl and economic growth. This process causes substantial damages to the urban infrastructure and housing structures and in several cities it is becoming a major factor to be considered when planning urban development, land use zoning and hazard mitigation strategies in the next decades. Subsidence is usually associated with aggressive groundwater extraction rates and a general decrease of aquifer static level that promotes soil consolidation, deformation and ultimately, surface faulting. However, local stratigraphic and structural conditions also play an important role in the development and extension of faults. Despite its potential for damaging housing, and other urban infrastructure, the economic impact of this phenomena is poorly known, in part because detailed, city-wide subsidence induced faulting risk maps have not been published before. Nevertheless, modern remote sensing techniques are most suitable for this task. We present the results of a risk analysis for subsidence induced surface faulting in two cities in central Mexico: Morelia and Mexico City. Our analysis in Mexico City and Morelia is based on a risk matrix using the horizontal subsidence gradient from a Persistent Scatterer InSAR (Morelia) and SqueeSAR (Mexico City) analysis and 2010 census population distribution data from Mexico's National Institute of Statistics and Geography. Defining subsidence induced surface faulting vulnerability within these urbanized areas is best determined using both magnitude and horizontal subsidence gradient. Our Morelia analysis (597,000 inhabitants with localized subsidence rates up to 80 mm/yr) shows that 7% of the urbanized area is under a high to very high risk level, and 14% of its population (11.7% and 2.3% respectively) lives within these areas. In the case of the Mexico City (15'490,000 inhabitants for the Mexico city Metropolitan area included within our map, and up to 370 mm/yr subsidence rate) our risk map shows that 13.5% of the urbanized area is under a high to very high risk level, and 26.2% of its population (22.1% and 4.4% respectively) lives within these areas.

Temporal and spatial changes of land use and landscape in a coal mining area in Xilingol grassland

NASA Astrophysics Data System (ADS)

Guan, Chunzhu; Zhang, Baolin; Li, Jiannan; Zhao, Junling

2017-01-01

Coal mining, particularly surface mining, inevitably disturbs land. According to Landsat images acquired over Xilingol grassland in 2005, 2009 and 2015, land uses were divided into seven classes, i. e., open stope, stripping area, waste-dump area, mine industrial area, farmland, urban area and the original landscape (grassland), using supervised classification and human-computer interactive interpretation. The overall classification accuracies were 97.72 %, 98.43 % and 96.73 %, respectively; the Kappa coefficients were 0.95, 0.97 and 0.95, respectively. Analysis on LUCC (Land Use and Cover Change) showed that surface coal mining disturbed grassland ecosystem: grassland decreased by 8661.15 hm2 in 2005-2015. The area and proportion of mining operation areas (open stope, stripping area, waste-dump area, mine industrial field) increased, but those of grassland decreased continuously. Transfer matrix of land use changes showed that waste-dump had the largest impacts in mining disturbance, and that effective reclamation of waste-dump areas would mitigate eco-environment destruction, as would be of great significance to protect fragile grassland eco-system. Six landscape index showed that landscape fragmentation increased, and the influences of human activity on landscape was mainly reflected in the expansion of mining area and urban area. Remote sensing monitoring of coal surface mining in grassland would accurately demonstrate the dynamics and trend of LUCC, providing scientific supports for ecological reconstruction in surface mining area.

Geothermal area detection using Landsat ETM+ thermal infrared data and its mechanistic analysis—A case study in Tengchong, China

NASA Astrophysics Data System (ADS)

Qin, Qiming; Zhang, Ning; Nan, Peng; Chai, Leilei

2011-08-01

Thermal infrared (TIR) remote sensing is an important technique in the exploration of geothermal resources. In this study, a geothermal survey is conducted in Tengchong area of Yunnan province in China using TIR data from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) sensor. Based on radiometric calibration, atmospheric correction and emissivity calculation, a simple but efficient single channel algorithm with acceptable precision is applied to retrieve the land surface temperature (LST) of study area. The LST anomalous areas with temperature about 4-10 K higher than background area are discovered. Four geothermal areas are identified with the discussion of geothermal mechanism and the further analysis of regional geologic structure. The research reveals that the distribution of geothermal areas is consistent with the fault development in study area. Magmatism contributes abundant thermal source to study area and the faults provide thermal channels for heat transfer from interior earth to land surface and facilitate the present of geothermal anomalies. Finally, we conclude that TIR remote sensing is a cost-effective technique to detect LST anomalies. Combining TIR remote sensing with geological analysis and the understanding of geothermal mechanism is an accurate and efficient approach to geothermal area detection.

Water quality responses to the interaction between surface water and groundwater along the Songhua River, NE China

NASA Astrophysics Data System (ADS)

Teng, Yanguo; Hu, Bin; Zheng, Jieqiong; Wang, Jinsheng; Zhai, Yuanzheng; Zhu, Chen

2018-03-01

Investigation of surface water and groundwater interaction (SW-GW interaction) provides basic information for regional water-resource protection, management, and development. In this survey of a 10-km-wide area along both sides of the Songhua River, northeast China, the hydrogeochemical responses to different SW-GW interactions were studied. Three types of SW-GW interactions were identified—"recharge", "discharge", and "flow-through"—according to the hydraulic connection between the surface water and groundwater. The single factor index, principal component analysis, and hierarchical cluster analysis of the hydrogeochemistry and pollutant data illuminated the hydrogeochemical response to the various SW-GW interactions. Clear SW-GW interactions along the Songhua River were revealed: (1) upstream in the study area, groundwater usually discharges into the surface water, (2) groundwater is recharged by surface water downstream, and (3) discharge and flow-through coexist in between. Statistical analysis indicated that the degree of hydrogeochemical response in different types of hydraulic connection varied, being clear in recharge and flow-through modes, and less obvious in discharge mode. During the interaction process, dilution, adsorption, redox reactions, nitrification, denitrification, and biodegradation contributed to the pollutant concentration and affected hydrogeochemical response in the hyporheic zone.

Integration of geological remote-sensing techniques in subsurface analysis

USGS Publications Warehouse

Taranik, James V.; Trautwein, Charles M.

1976-01-01

Geological remote sensing is defined as the study of the Earth utilizing electromagnetic radiation which is either reflected or emitted from its surface in wavelengths ranging from 0.3 micrometre to 3 metres. The natural surface of the Earth is composed of a diversified combination of surface cover types, and geologists must understand the characteristics of surface cover types to successfully evaluate remotely-sensed data. In some areas landscape surface cover changes throughout the year, and analysis of imagery acquired at different times of year can yield additional geological information. Integration of different scales of analysis allows landscape features to be effectively interpreted. Interpretation of the static elements displayed on imagery is referred to as an image interpretation. Image interpretation is dependent upon: (1) the geologist's understanding of the fundamental aspects of image formation, and (2.) his ability to detect, delineate, and classify image radiometric data; recognize radiometric patterns; and identify landscape surface characteristics as expressed on imagery. A geologic interpretation integrates surface characteristics of the landscape with subsurface geologic relationships. Development of a geologic interpretation from imagery is dependent upon: (1) the geologist's ability to interpret geomorphic processes from their static surface expression as landscape characteristics on imagery, (2) his ability to conceptualize the dynamic processes responsible for the evolution 6f interpreted geologic relationships (his ability to develop geologic models). The integration of geologic remote-sensing techniques in subsurface analysis is illustrated by development of an exploration model for ground water in the Tucson area of Arizona, and by the development of an exploration model for mineralization in southwest Idaho.

Surface water sampling and analysis plan for environmental monitoring in Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

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

Not Available

1994-06-01

This Sampling and Analysis Plan addresses surface water monitoring, sampling, and analysis activities that will be conducted in support of the Environmental Monitoring Plan for Waste Area Grouping (WAG) 6. WAG 6 is a shallow-burial land disposal facility for low-level radioactive waste at the Oak Ridge National Laboratory, a research facility owned by the US Department of Energy and managed by Martin Marietta Energy Systems, Inc. Surface water monitoring will be conducted at nine sites within WAG 6. Activities to be conducted will include the installation, inspection, and maintenance of automatic flow-monitoring and sampling equipment and manual collection of variousmore » water and sediment samples. The samples will be analyzed for various organic, inorganic, and radiological parameters. The information derived from the surface water monitoring, sampling, and analysis will aid in evaluating risk associated with contaminants migrating off-WAG, and will be used in calculations to establish relationships between contaminant concentration (C) and flow (Q). The C-Q relationship will be used in calculating the cumulative risk associated with the off-WAG migration of contaminants.« less

Application and Evaluation of ALOS PALSAR Data for Monitoring of Mining Induced Surface Deformations Using Interferometric Techniques

NASA Astrophysics Data System (ADS)

Walter, Diana; Wegmuller, Urs; Spreckels, Volker; Busch, Wolfgang

2008-11-01

The main objective of the projects "Determination of ground motions in mining areas by interferometric analyses of ALOS data" (ALOS ADEN 3576, ESA) and "Monitoring of mining induced surface deformation" (ALOS-RA-094, JAXA) is to evaluate PALSAR data for surface deformation monitoring, using interferometric techniques. We present monitoring results of surface movements for an active hard coal colliery of the German hard coal mining company RAG Deutsche Steinkohle (RAG). Underground mining activities lead to ground movements at the surface with maximum subsidence rates of about 10cm per month for the test site. In these projects the L-band sensor clearly demonstrates the good potential for deformation monitoring in active mining areas, especially in rural areas. In comparison to C-band sensors we clearly observe advantages in resolving the high deformation gradients that are present in this area and we achieve a more complete spatial coverage than with C-band. Extensive validation data based on levelling data and GPS measurements are available within RAǴs GIS based database "GeoMon" and thus enable an adequate analysis of the quality of the interferometric results. Previous analyses confirm the good accuracy of PALSAR data for deformation monitoring in mining areas. Furthermore, we present results of special investigations like precision geocoding of PALSAR data and corner reflector analysis. At present only DInSAR results are obtained due to the currently available number of PALSAR scenes. For the future we plan to also apply Persistent Scatterer Interferometry (PSI) using longer series of PALSAR data.

Does pelvicaliceal system anatomy affect success of percutaneous nephrolithotomy?

PubMed

Binbay, Murat; Akman, Tolga; Ozgor, Faruk; Yazici, Ozgur; Sari, Erhan; Erbin, Akif; Kezer, Cem; Sarilar, Omer; Berberoglu, Yalcın; Muslumanoglu, Ahmet Yaser

2011-10-01

To investigate the effect of the pelvicaliceal system (PCS) anatomy on the percutaneous nephrolithotomy (PCNL) success rate. Although the caliceal anatomy is effective for stone clearance after shock wave lithotripsy and retrograde intrarenal lithotripsy, the effect of the caliceal anatomy after PCNL has not been evaluated to date. A total of 498 patients who had undergone PCNL and preoperative intravenous urography were enrolled in our study. Kidney-related anatomic factors, such as the PCS surface area and type, degree of hydronephrosis, infundibulopelvic angle, upper-lower calix angle, infundibular length, and infundibular width were calculated using intravenous urography. The association between the PCNL success rate and kidney-related anatomic factors was retrospectively analyzed using chi-square tests, Fisher's exact test, Mann-Whitney U test, and forward stepwise regression analysis. A success rate of 78.1% was achieved. No difference was seen the success rates among the PCS types. The mean PCS surface area was 20.1 ± 9.7 cm(2) in patients with successful outcomes and 24.5 ± 10.2 cm(2) in patients with remaining stones (P = .001). The mean infundibulopelvic angle, upper-lower calix angle, infundibular length, and infundibular width were similar in both groups. Multivariate binary logistic regression analysis showed that stone configuration and PCS surface area were independent factors affecting the PCNL success rates. The results of our study have shown that the PCS surface area is the only anatomic factor that affects the PCNL success rate and patients with a PCS surface area <20.5 cm(2) have greater PCNL success. Copyright © 2011 Elsevier Inc. All rights reserved.

The spatial-temporal dynamics of open surface water bodies in CONUS during 1984-2016

NASA Astrophysics Data System (ADS)

Zou, Z.; Xiao, X.; Dong, J.; Qin, Y.; Doughty, R.; Menarguez, M.; Wang, J.

2017-12-01

Open surface water bodies provided 80% of the total water withdrawals in the Contiguous United States (CONUS) in 1985-2010. The inter-annual variability and changing trends of surface water body areas have various impacts on the human society and ecosystems. This study made use of all Landsat 5, 7, and 8 surface reflectance archives ( 370,000 images) during 1984-2016 and a water index- and pixel-based approach to detect and map open surface water bodies in the cloud-based platform of Google Earth Engine. The year-long water body area and annual average water body area were calculated for each of the last 33 years and their inter-annual variations during 1984-2016 were analyzed through anomaly analysis while their changing trends were analyzed through linear regressions. The national annual average water body areas varied from 265,000 to 281,000 km2 during 1984-2016, which is 3% below to 3% above the mean value 274,000 km2. In state level, significant decreasing trends were found in both year-long and annual average water body areas in some states of dry climates in west and southwest U.S., including Oregon, Nevada, Utah, Arizona, New Mexico, and Oklahoma. In comparison, significant increasing trends were found in some states of wet climates in the southeast and north U.S., including Indiana, Ohio, New Jersey, Delaware, Virginia, Tennessee, North Carolina, South Carolina, Louisiana, Alabama, Georgia, North Dakota and South Dakota. Open surface water body areas in CONUS decreased in relatively dry areas but increased in relatively wet areas. The relationships between open surface water body area variability and climate factors (precipitation, temperature) and human impacts (water exploitation) were also analyzed.

A comparison of stereology, structural rigidity and a novel 3D failure surface analysis method in the assessment of torsional strength and stiffness in a mouse tibia fracture model.

PubMed

Wright, David A; Nam, Diane; Whyne, Cari M

2012-08-31

In attempting to develop non-invasive image based measures for the determination of the biomechanical integrity of healing fractures, traditional μCT based measurements have been limited. This study presents the development and evaluation of a tool for assessment of fracture callus mechanical properties through determination of the geometric characteristics of the fracture callus, specifically along the surface of failure identified during destructive mechanical testing. Fractures were created in tibias of ten male mice and subjected to μCT imaging and biomechanical torsion testing. Failure surface analysis, along with previously described image based measures was calculated using the μCT image data, and correlated with mechanical strength and stiffness. Three-dimensional measures along the surface of failure, specifically the surface area and torsional rigidity of bone, were shown to be significantly correlating with mechanical strength and stiffness. It was also shown that surface area of bone along the failure surface exhibits stronger correlations with both strength and stiffness than measures of average and minimum torsional rigidity of the entire callus. Failure surfaces observed in this study were generally oriented at 45° to the long axis of the bone, and were not contained exclusively within the callus. This work represents a proof of concept study, and shows the potential utility of failure surface analysis in the assessment of fracture callus stability. Copyright © 2012 Elsevier Ltd. All rights reserved.

Can foot anthropometric measurements predict dynamic plantar surface contact area?

PubMed

McPoil, Thomas G; Vicenzino, Bill; Cornwall, Mark W; Collins, Natalie

2009-10-28

Previous studies have suggested that increased plantar surface area, associated with pes planus, is a risk factor for the development of lower extremity overuse injuries. The intent of this study was to determine if a single or combination of foot anthropometric measures could be used to predict plantar surface area. Six foot measurements were collected on 155 subjects (97 females, 58 males, mean age 24.5 +/- 3.5 years). The measurements as well as one ratio were entered into a stepwise regression analysis to determine the optimal set of measurements associated with total plantar contact area either including or excluding the toe region. The predicted values were used to calculate plantar surface area and were compared to the actual values obtained dynamically using a pressure sensor platform. A three variable model was found to describe the relationship between the foot measures/ratio and total plantar contact area (R2 = 0.77, p < 0.0001)). A three variable model was also found to describe the relationship between the foot measures/ratio and plantar contact area minus the toe region (R2 = 0.76, p < 0.0001). The results of this study indicate that the clinician can use a combination of simple, reliable, and time efficient foot anthropometric measurements to explain over 75% of the plantar surface contact area, either including or excluding the toe region.

Can foot anthropometric measurements predict dynamic plantar surface contact area?

PubMed Central

2009-01-01

Background Previous studies have suggested that increased plantar surface area, associated with pes planus, is a risk factor for the development of lower extremity overuse injuries. The intent of this study was to determine if a single or combination of foot anthropometric measures could be used to predict plantar surface area. Methods Six foot measurements were collected on 155 subjects (97 females, 58 males, mean age 24.5 ± 3.5 years). The measurements as well as one ratio were entered into a stepwise regression analysis to determine the optimal set of measurements associated with total plantar contact area either including or excluding the toe region. The predicted values were used to calculate plantar surface area and were compared to the actual values obtained dynamically using a pressure sensor platform. Results A three variable model was found to describe the relationship between the foot measures/ratio and total plantar contact area (R2 = 0.77, p < 0.0001)). A three variable model was also found to describe the relationship between the foot measures/ratio and plantar contact area minus the toe region (R2 = 0.76, p < 0.0001). Conclusion The results of this study indicate that the clinician can use a combination of simple, reliable, and time efficient foot anthropometric measurements to explain over 75% of the plantar surface contact area, either including or excluding the toe region. PMID:19863799

Potential impacts of the Deepwater Horizon oil spill on large pelagic fishes

NASA Astrophysics Data System (ADS)

Frias-Torres, Sarrah; Bostater, Charles R., Jr.

2011-11-01

Biogeographical analyses provide insights on how the Deepwater Horizon oil spill impacted large pelagic fishes. We georeferenced historical ichthyoplankton surveys and published literature to map the spawning and larval areas of bluefin tuna, swordfish, blue marlin and whale shark sightings in the Gulf of Mexico with daily satellite-derived images detecting surface oil. The oil spill covered critical areas used by large pelagic fishes. Surface oil was detected in 100% of the northernmost whale shark sightings, in 32.8 % of the bluefin tuna spawning area and 38 % of the blue marlin larval area. No surface oil was detected in the swordfish spawning and larval area. Our study likely underestimates the extend of the oil spill due to satellite sensors detecting only the upper euphotic zone and the use of dispersants altering crude oil density, but provides a previously unknown spatio-temporal analysis.

Experiment Study on Determination of Surface Area of Finegrained Soils by Mercury Intrusion Porosimetry

NASA Astrophysics Data System (ADS)

Yan, X. Q.; Zhou, C. Y.; Fang, Y. G.; Lin, L. S.

2017-12-01

The specific surface area (SSA) has a great influence on the physical and chemical properties of fine-grained soils. Determination of specific surface area is an important content for fine-grained soils micro-meso analysis and characteristic research. In this paper, mercury intrusion porosimetry (MIP) was adopted to determine the SSA of fine-grained soils including quartz, kaolinite, bentonite and natural Shenzhen soft clay. The test results show that the average values of SSA obtained by MIP are 0.78m2/g, 11.31m2/g, 57.28m2/g and 27.15m2/g respectively for very fine-grained quartz, kaolin, bentonite and natural Shenzhen soft clay, and that it is feasible to apply MIP to obtain the SSA of fine-grained soils through statistical analysis of 97 samples. Through discussion, it is necessary to consider the state of fine-grained soils such as pore ratio when the SSA of fine-grained soils is determined by MIP.

Representation of vegetation by continental data sets derived from NOAA-AVHRR data

NASA Technical Reports Server (NTRS)

Justice, C. O.; Townshend, J. R. G.; Kalb, V. L.

1991-01-01

Images of the normalized difference vegetation index (NDVI) are examined with specific attention given to the effect of spatial scales on the understanding of surface phenomena. A scale variance analysis is conducted on NDVI annual and seasonal images of Africa taken from 1987 NOAA-AVHRR data at spatial scales ranging from 8-512 km. The scales at which spatial variation takes place are determined and the relative magnitude of the variations are considered. Substantial differences are demonstrated, notably an increase in spatial variation with coarsening spatial resolution. Different responses in scale variance as a function of spatial resolution are noted in an analysis of maximum value composites for February and September; the difference is most marked in areas with very seasonal vegetation. The spatial variation at different scales is attributed to different factors, and methods involving the averaging of areas of transition and surface heterogeneity can oversimplify surface conditions. The spatial characteristics and the temporal variability of areas should be considered to accurately apply satellite data to global models.

Water quality studied in areas of unconventional oil and gas development, including areas where hydraulic fracturing techniques are used, in the United States

USGS Publications Warehouse

Susong, David D.; Gallegos, Tanya J.; Oelsner, Gretchen P.

2012-01-01

The U.S. Geological Survey (USGS) John Wesley Powell Center for Analysis and Synthesis is hosting an interdisciplinary working group of USGS scientists to conduct a temporal and spatial analysis of surface-water and groundwater quality in areas of unconventional oil and gas development. The analysis uses existing national and regional datasets to describe water quality, evaluate water-quality changes over time where there are sufficient data, and evaluate spatial and temporal data gaps.

Surface roughness formation during shot peen forming

NASA Astrophysics Data System (ADS)

Koltsov, V. P.; Vinh, Le Tri; Starodubtseva, D. A.

2018-03-01

Shot peen forming (SPF) is used for forming panels and skins, and for hardening. As a rule, shot peen forming is performed after milling. Surface roughness is a complex structure, a combination of an original microrelief and shot peen forming indentations of different depths and chaotic distribution along the surface. As far as shot peen forming is a random process, surface roughness resulted from milling and shot peen forming is random too. During roughness monitoring, it is difficult to determine the basic surface area which would ensure accurate results. It can be assumed that the basic area depends on the random roughness which is characterized by the degree of shot peen forming coverage. The analysis of depth and shot peen forming indentations distribution along the surface made it possible to identify the shift of an original center profile plane and create a mathematical model for the arithmetic mean deviation of the profile. Experimental testing proved model validity and determined an inversely proportional dependency of the basic area on the degree of coverage.

Exploring Surface Analysis Techniques for the Detection of Molecular Contaminants on Spacecraft

NASA Technical Reports Server (NTRS)

Rutherford, Gugu N.; Seasly, Elaine; Thornblom, Mark; Baughman, James

2016-01-01

Molecular contamination is a known area of concern for spacecraft. To mitigate this risk, projects involving space flight hardware set requirements in a contamination control plan that establishes an allocation budget for the exposure of non-volatile residues (NVR) onto critical surfaces. The purpose of this work will focus on non-contact surface analysis and in situ monitoring to mitigate molecular contamination on space flight hardware. By using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (SEM-EDS) with Raman Spectroscopy, an unlikely contaminant was identified on space flight hardware. Using traditional and surface analysis methods provided the broader view of the contamination sources allowing for best fit solutions to prevent any future exposure.

Impact of Baseline Disease Severity Over 26 and 52 Weeks of Treatment with Calcitriol Ointment 3µg/g in Patients with Mild-to-moderate Plaque Psoriasis.

PubMed

Lebwohl, Mark; Preston, Norman; Gottschalk, Ronald W

2012-02-01

Calcitriol 3µg/g ointment has been shown to be a safe and effective treatment for adults with mild-to-moderate plaque psoriasis. This analysis evaluated the response to calcitriol 3µg/g ointment relative to baseline disease. Retrospective analysis of data from a 12-month safety and tolerability trial. At baseline, 40.1 percent (130/324) of patients had an affected body surface area of 11 to 20 percent, and 55.2 percent (179/324) had moderate and 25.9 percent (84/324) had severe disease according to global severity score. Patients applied calcitriol 3µg/g ointment twice daily for up to 52 weeks. Change in investigator's global severity scores and involved body surface area at Week 26 (N=249) and Week 52 (N=130) relative to baseline. Compared with baseline, most patients experienced at least a 1-grade improvement in global severity score at Weeks 26 (195/249, 78.3%) and 52 (109/130, 83.8%). Stabilization (i.e., no change in global severity score) was reported in 19.3 percent (48/249) at Week 26 and in 12.3 percent (16/130) at Week 52. Most patients also experienced at least a 1-grade improvement in body surface area involved at Weeks 26 (152/249, 61.0%) and 52 (95/130, 73.1%). Stabilization (no change in affected body surface area) was reported in 32.5 percent (81/249) at Week 26 and 24.6 percent (32/130) at Week 52. The proportion of patients experiencing improvement in global severity score and body surface area was comparable across all categories of severity and disease extent at baseline. This analysis suggests that calcitriol 3µg/g ointment use for 26 weeks (N=249) and 52 weeks (N=130) was associated with disease improvement or stabilization in most patients with plaque psoriasis.

Fractography of ceramic and metal failures

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

Not Available

1984-01-01

STP 827 is organized into the two broad areas of ceramics and metals. The ceramics section covers fracture analysis techniques, surface analysis techniques, and applied fractography. The metals section covers failure analysis techniques, and latest approaches to fractography, and applied fractography.

Comparison of four methods of surface roughness assessment of corneal stromal bed after lamellar cutting

PubMed Central

Jumelle, Clotilde; Hamri, Alina; Egaud, Gregory; Mauclair, Cyril; Reynaud, Stephanie; Dumas, Virginie; Pereira, Sandrine; Garcin, Thibaud; Gain, Philippe; Thuret, Gilles

2017-01-01

Corneal lamellar cutting with a blade or femtosecond laser (FSL) is commonly used during refractive surgery and corneal grafts. Surface roughness of the cutting plane influences postoperative visual acuity but is difficult to assess reliably. For the first time, we compared chromatic confocal microscopy (CCM) with scanning electron microscopy, atomic force microscopy (AFM) and focus-variation microscopy (FVM) to characterize surfaces of variable roughness after FSL cutting. The small area allowed by AFM hinders conclusive roughness analysis, especially with irregular cuts. FVM does not always differentiate between smooth and rough surfaces. Finally, CCM allows analysis of large surfaces and differentiates between surface states. PMID:29188095

High-resolution surface analysis for extended-range downscaling with limited-area atmospheric models

NASA Astrophysics Data System (ADS)

Separovic, Leo; Husain, Syed Zahid; Yu, Wei; Fernig, David

2014-12-01

High-resolution limited-area model (LAM) simulations are frequently employed to downscale coarse-resolution objective analyses over a specified area of the globe using high-resolution computational grids. When LAMs are integrated over extended time frames, from months to years, they are prone to deviations in land surface variables that can be harmful to the quality of the simulated near-surface fields. Nudging of the prognostic surface fields toward a reference-gridded data set is therefore devised in order to prevent the atmospheric model from diverging from the expected values. This paper presents a method to generate high-resolution analyses of land-surface variables, such as surface canopy temperature, soil moisture, and snow conditions, to be used for the relaxation of lower boundary conditions in extended-range LAM simulations. The proposed method is based on performing offline simulations with an external surface model, forced with the near-surface meteorological fields derived from short-range forecast, operational analyses, and observed temperatures and humidity. Results show that the outputs of the surface model obtained in the present study have potential to improve the near-surface atmospheric fields in extended-range LAM integrations.

[Size distribution characteristics of particulate matter in the top areas of coke oven].

PubMed

Xie, Qiuyan; Zhao, Hongwei; Yu, Tao; Ning, Zhaojun; Li, Jinmu; Niu, Yong; Zheng, Yuxin; Zhao, Xiulan; Duan, Huawei

2015-03-01

To systematically evaluate the environmental exposure information of coke oven workers, we investigated the concentration and size distribution characteristics of the particle matter (PM) in the top working area of coke oven. The aerodynamic particle sizer spectrometer was employed to collect the concentration and size distribution information of PM at a top working area. The PM was divided into PM ≤ 1.0 µm, 1.0 µm < PM ≤ 2.5 µm, 2.5 µm < PM ≤ 5.0 µm, 5.0 µm < PM ≤ 10.0 µm and PM>10.0 µm based on their aerodynamic diameters. The number concentration, surface area concentration, and mass concentration were analyzed between different groups. We also conducted the correlation analysis on these parameters among groups. We found the number and surface area concentration of top area particulate was negatively correlated with particle size, but mass concentration curve showed bimodal type with higher point at PM = 1.0 µm and PM = 5.0 µm. The average number concentration of total particulate matter in the top working area was 661.27 number/cm³, surface area concentration was 523.92 µm²/cm³, and mass concentration was 0.12 mg/m³. The most number of particulate matter is not more than 1 µm (PM(1.0)), and its number concentration and surface area concentration accounted for 96.85% and 67.01% of the total particles respectively. In the correlation analysis, different particle size correlated with the total particulate matter differently. And the characteristic parameters of PM2.5 cannot fully reflect the total information of particles. The main particulate matter pollutants in the top working area of coke oven is PM1.0, and it with PM(5.0) can account for a large proportion in the mass concentration of PM. It suggest that PM1.0 and PM(5.0) should be considered for occupational health surveillance on the particulate matter in the top area of coke oven.

Physical Activation of Oil Palm Empty Fruit Bunch via CO2 Activation Gas for CO2 Adsorption

NASA Astrophysics Data System (ADS)

Joseph, C. G.; Quek, K. S.; Daud, W. M. A. W.; Moh, P. Y.

2017-06-01

In this study, different parameters for the preparation of activated carbon were investigated for their yield and CO2 capture capabilities. The activated carbon was prepared from Oil Palm Empty Fruit Bunch (OPEFB) via a 2-step physical activation process. The OPEFB was pyrolyzed under inert conditions at 500 °C and activated via CO2. A 2-factorial design was employed and the effects of activation temperature, activation dwell time and gas flow rate on yield and CO2 capture capabilities were compared and studied. The yield obtained ranged from between 20 - 26, whereby the temperature was determined to be the most significant factor in influencing CO2 uptake. The CO2 capture capacity was determined using Temperature Programmed Desorption (TPD) technique. The CO2 uptake of EFB activated carbon achieved was between 1.85 - 2.09 mmol/g. TPD analysis has shown that the surface of AC were of basic nature. AC was found to be able to withhold the CO2 up to 663°C before maximum desorption occurs. The surface area and pore size of OPEFB obtained from BET analysis is 2.17 m2 g-1 and 0.01 cm3 g-1. After activation, both surface area and pore size increased with a maximum observed surface area and pore size of 548.07 m2 g-1 and 0.26 cm3 g-1. Surface morphology, functional groups, pore size and surface area were analyzed using SEM, FT-IR, TPD and BET.

Groundwater recharge in suburban areas of Hanoi, Vietnam: effect of decreasing surface-water bodies and land-use change

NASA Astrophysics Data System (ADS)

Kuroda, Keisuke; Hayashi, Takeshi; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Funabiki, Ayako; Takizawa, Satoshi

2017-05-01

Over-exploited groundwater is expected to remain the predominant source of domestic water in suburban areas of Hanoi, Vietnam. In order to evaluate the effect on groundwater recharge, of decreasing surface-water bodies and land-use change caused by urbanization, the relevant groundwater systems and recharge pathways must be characterized in detail. To this end, water levels and water quality were monitored for 3 years regarding groundwater and adjacent surface-water bodies, at two typical suburban sites in Hanoi. Stable isotope (δ18O, δD of water) analysis and hydrochemical analysis showed that the water from both aquifers and aquitards, including the groundwater obtained from both the monitoring wells and the neighboring household tubewells, was largely derived from evaporation-affected surface-water bodies (e.g., ponds, irrigated farmlands) rather than from rivers. The water-level monitoring results suggested distinct local-scale flow systems for both a Holocene unconfined aquifer (HUA) and Pleistocene confined aquifer (PCA). That is, in the case of the HUA, lateral recharge through the aquifer from neighboring ponds and/or irrigated farmlands appeared to be dominant, rather than recharge by vertical rainwater infiltration. In the case of the PCA, recharge by the above-lying HUA, through areas where the aquitard separating the two aquifers was relatively thin or nonexistent, was suggested. As the decrease in the local surface-water bodies will likely reduce the groundwater recharge, maintaining and enhancing this recharge (through preservation of the surface-water bodies) is considered as essential for the sustainable use of groundwater in the area.

Dissolution process analysis using model-free Noyes-Whitney integral equation.

PubMed

Hattori, Yusuke; Haruna, Yoshimasa; Otsuka, Makoto

2013-02-01

Drug dissolution process of solid dosages is theoretically described by Noyes-Whitney-Nernst equation. However, the analysis of the process is demonstrated assuming some models. Normally, the model-dependent methods are idealized and require some limitations. In this study, Noyes-Whitney integral equation was proposed and applied to represent the drug dissolution profiles of a solid formulation via the non-linear least squares (NLLS) method. The integral equation is a model-free formula involving the dissolution rate constant as a parameter. In the present study, several solid formulations were prepared via changing the blending time of magnesium stearate (MgSt) with theophylline monohydrate, α-lactose monohydrate, and crystalline cellulose. The formula could excellently represent the dissolution profile, and thereby the rate constant and specific surface area could be obtained by NLLS method. Since the long time blending coated the particle surface with MgSt, it was found that the water permeation was disturbed by its layer dissociating into disintegrant particles. In the end, the solid formulations were not disintegrated; however, the specific surface area gradually increased during the process of dissolution. The X-ray CT observation supported this result and demonstrated that the rough surface was dominant as compared to dissolution, and thus, specific surface area of the solid formulation gradually increased. Copyright © 2012 Elsevier B.V. All rights reserved.

Synthesis and catalytic activity of polysaccharide templated nanocrystalline sulfated zirconia

NASA Astrophysics Data System (ADS)

Sherly, K. B.; Rakesh, K.

2014-01-01

Nanoscaled materials are of great interest due to their unique enhanced optical, electrical and magnetic properties. Sulfate-promoted zirconia has been shown to exhibit super acidic behavior and high activity for acid catalyzed reactions. Nanocrystalline zirconia was prepared in the presence of polysaccharide template by interaction between ZrOCl2ṡ8H2O and chitosan template. The interaction was carried out in aqueous phase, followed by the removal of templates by calcination at optimum temperature and sulfation. The structural and textural features were characterized by powder XRD, TG, SEM and TEM. XRD patterns showed the peaks of the diffractogram were in agreement with the theoretical data of zirconia with the catalytically active tetragonal phase and average crystalline size of the particles was found to be 9 nm, which was confirmed by TEM. TPD using ammonia as probe, FTIR and BET surface area analysis were used for analyzing surface features like acidity and porosity. The BET surface area analysis showed the sample had moderately high surface area. FTIR was used to find the type species attached to the surface of zirconia. UV-DRS found the band gap of the zirconia was found to be 2.8 eV. The benzylation of o-xylene was carried out batchwise in atmospheric pressure and 433K temperature using sulfated zirconia as catalyst.

Experimental study of crack initiation and propagation in high- and gigacycle fatigue in titanium alloys

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

Bannikov, Mikhail, E-mail: mbannikov@icmm.ru, E-mail: oborin@icmm.ru, E-mail: naimark@icmm.ru; Oborin, Vladimir, E-mail: mbannikov@icmm.ru, E-mail: oborin@icmm.ru, E-mail: naimark@icmm.ru; Naimark, Oleg, E-mail: mbannikov@icmm.ru, E-mail: oborin@icmm.ru, E-mail: naimark@icmm.ru

Fatigue (high- and gigacycle) crack initiation and its propagation in titanium alloys with coarse and fine grain structure are studied by fractography analysis of fracture surface. Fractured specimens were analyzed by interferometer microscope and SEM to improve methods of monitoring of damage accumulation during fatigue test and to verify the models for fatigue crack kinetics. Fatigue strength was estimated for high cycle fatigue regime using the Luong method [1] by “in-situ” infrared scanning of the sample surface for the step-wise loading history for different grain size metals. Fine grain alloys demonstrated higher fatigue resistance for both high cycle fatigue andmore » gigacycle fatigue regimes. Fracture surface analysis for plane and cylindrical samples was carried out using optical and electronic microscopy method. High resolution profilometry (interferometer-profiler New View 5010) data of fracture surface roughness allowed us to estimate scale invariance (the Hurst exponent) and to establish the existence of two characteristic areas of damage localization (different values of the Hurst exponent). Area 1 with diameter ∼300 μm has the pronounced roughness and is associated with damage localization hotspot. Area 2 shows less amplitude roughness, occupies the rest fracture surface and considered as the trace of the fatigue crack path corresponding to the Paris kinetics.« less

Satellite data for surface-mine inventory. [in Maryland

NASA Technical Reports Server (NTRS)

Anderson, A. T.; Schultz, D.; Buchman, N.; Nock, M.

1976-01-01

To determine the feasibility of satellite data for surface-mine inventory, particularly as it applies to coal, a case study was conducted in Maryland. A band-ratio method was developed to measure disturbed surface areas, and it proved to be extendible both temporally and geographically. This method was used to measure area changes in the region over three time periods from September 1972 through July 1974 and to map the entire two-county area for 1973. For mines ranging between 31 and 244 acres (12 to 98 hectares) the measurement accuracy of total affected acreage was determined to be 92%. Mines of 120 acres (50 hectares) and larger were measured with greater accuracy, some within one percent of the actual area. The ability to identify, classify, and measure strip-mine surfaces in a two-county area (1,541 square kilometers - 595 square miles) of western Maryland was demonstrated through the use of computer processing. On the basis of these results the use of LANDSAT satellite data and multilevel sampling of aircraft and field verification inspections, multispectral analysis of digital data is shown to be an effective, rapid, and accurate means of monitoring the surface mining cycle.

PIXE analysis of caries related trace elements in tooth enamel

NASA Astrophysics Data System (ADS)

Annegarn, H. J.; Jodaikin, A.; Cleaton-Jones, P. E.; Sellschop, J. P. F.; Madiba, C. C. P.; Bibby, D.

1981-03-01

PIXE analysis has been applied to a set of twenty human teeth to determine trace element concentration in enamel from areas susceptible to dental caries (mesial and distal contact points) and in areas less susceptible to the disease (buccal surfaces), with the aim of determining the possible roles of trace elements in the curious process. The samples were caries-free anterior incisors extracted for periodontal reasons from subjects 10-30 years of age. Prior to extraction of the sample teeth, a detailed dental history and examination was carried out in each individual. PIXE analysis, using a 3 MeV proton beam of 1 mm diameter, allowed the determination of Ca, Mn, Fe, Cu, Zn, Sr and Pb above detection limits. As demonstrated in this work, the enhanced sensitivity of PIXE analysis over electron microprobe analysis, and the capability of localised surface analysis compared with the pooled samples required for neutron activation analysis, makes it a powerful and useful technique in dental analysis.

A Surface-based Analysis of Language Lateralization and Cortical Asymmetry

PubMed Central

Greve, Douglas N.; Van der Haegen, Lise; Cai, Qing; Stufflebeam, Steven; Sabuncu, Mert R.; Fischl, Bruce; Bysbaert, Marc

2013-01-01

Among brain functions, language is one of the most lateralized. Cortical language areas are also some of the most asymmetrical in the brain. An open question is whether the asymmetry in function is linked to the asymmetry in anatomy. To address this question, we measured anatomical asymmetry in 34 participants shown with fMRI to have language dominance of the left hemisphere (LLD) and 21 participants shown to have atypical right hemisphere dominance (RLD). All participants were healthy and left-handed, and most (80%) were female. Gray matter (GM) volume asymmetry was measured using an automated surface-based technique in both ROIs and exploratory analyses. In the ROI analysis, a significant difference between LLD and RLD was found in the insula. No differences were found in planum temporale (PT), pars opercularis (POp), pars triangularis (PTr), or Heschl’s gyrus (HG). The PT, POp, insula, and HG were all significantly left lateralized in both LLD and RLD participants. Both the positive and negative ROI findings replicate a previous study using manually labeled ROIs in a different cohort [Keller, S. S., Roberts, N., Garcia-Finana, M., Mohammadi, S., Ringelstein, E. B., Knecht, S., et al. Can the language-dominant hemisphere be predicted by brain anatomy? Journal of Cognitive Neuroscience, 23, 2013–2029, 2011]. The exploratory analysis was accomplished using a new surface-based registration that aligns cortical folding patterns across both subject and hemisphere. A small but significant cluster was found in the superior temporal gyrus that overlapped with the PT. A cluster was also found in the ventral occipitotemporal cortex corresponding to the visual word recognition area. The surface-based analysis also makes it possible to disentangle the effects of GM volume, thickness, and surface area while removing the effects of curvature. For both the ROI and exploratory analyses, the difference between LLD and RLD volume laterality was most strongly driven by differences in surface area and not cortical thickness. Overall, there were surprisingly few differences in GM volume asymmetry between LLD and RLD indicating that gross morphometric asymmetry is only subtly related to functional language laterality. PMID:23701459

Synthesis and characterization of Co3O4 prepared from atmospheric pressure acid leach liquors of nickel laterite ores

NASA Astrophysics Data System (ADS)

Meng, Long; Guo, Zhan-cheng; Qu, Jing-kui; Qi, Tao; Guo, Qiang; Hou, Gui-hua; Dong, Peng-yu; Xi, Xin-guo

2018-01-01

A chemical precipitation-thermal decomposition method was developed to synthesize Co3O4 nanoparticles using cobalt liquor obtained from the atmospheric pressure acid leaching process of nickel laterite ores. The effects of the precursor reaction temperature, the concentration of Co2+, and the calcination temperature on the specific surface area, morphology, and the electrochemical behavior of the obtained Co3O4 particles were investigated. The precursor basic cobaltous carbonate and cobaltosic oxide products were characterized and analyzed by Fourier transform infrared spectroscopy, thermogravimetric differential thermal analysis, X-ray diffraction, field-emission scanning electron microscopy, specific surface area analysis, and electrochemical analysis. The results indicate that the specific surface area of the Co3O4 particles with a diameter of 30 nm, which were obtained under the optimum conditions of a precursor reaction temperature of 30°C, 0.25 mol/L Co2+, and a calcination temperature of 350°C, was 48.89 m2/g. Electrodes fabricated using Co3O4 nanoparticles exhibited good electrochemical properties, with a specific capacitance of 216.3 F/g at a scan rate of 100 mV/s.

Remote sensing and GIS for mapping groundwater recharge and discharge areas in salinity prone catchments, southeastern Australia

NASA Astrophysics Data System (ADS)

Tweed, Sarah O.; Leblanc, Marc; Webb, John A.; Lubczynski, Maciek W.

2007-02-01

Identifying groundwater recharge and discharge areas across catchments is critical for implementing effective strategies for salinity mitigation, surface-water and groundwater resource management, and ecosystem protection. In this study, a synergistic approach has been developed, which applies a combination of remote sensing and geographic information system (GIS) techniques to map groundwater recharge and discharge areas. This approach is applied to an unconfined basalt aquifer, in a salinity and drought prone region of southeastern Australia. The basalt aquifer covers ~11,500 km2 in an agriculturally intensive region. A review of local hydrogeological processes allowed a series of surface and subsurface indicators of groundwater recharge and discharge areas to be established. Various remote sensing and GIS techniques were then used to map these surface indicators including: terrain analysis, monitoring of vegetation activity, and mapping of infiltration capacity. All regions where groundwater is not discharging to the surface were considered potential recharge areas. This approach, applied systematically across a catchment, provides a framework for mapping recharge and discharge areas. A key component in assigning surface and subsurface indicators is the relevance to the dominant recharge and discharge processes occurring and the use of appropriate remote sensing and GIS techniques with the capacity to identify these processes.

Final report of CCQM-K136 measurement of porosity properties (specific adsorption, BET specific surface area, specific pore volume and pore diameter) of nanoporous Al2O3

NASA Astrophysics Data System (ADS)

Sobina, E.; Zimathis, A.; Prinz, C.; Emmerling, F.; Unger, W.; de Santis Neves, R.; Galhardo, C. E.; De Robertis, E.; Wang, H.; Mizuno, K.; Kurokawa, A.

2016-01-01

CCQM key comparison K-136 Measurement of porosity properties (specific adsorption, BET specific surface area, specific pore volume and pore diameter) of nanoporous Al2O3 has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The objective of this key comparison is to compare the equivalency of the National Metrology Institutes (NMIs) and Designated Institutes (DIs) for the measurement of specific adsorption, BET specific surface area, specific pore volume and pore diameter) of nanoporous substances (sorbents, catalytic agents, cross-linkers, zeolites, etc) used in advanced technology. In this key comparison, a commercial sorbent (aluminum oxide) was supplied as a sample. Five NMIs participated in this key comparison. All participants used a gas adsorption method, here nitrogen adsorption at 77.3 K, for analysis according to the international standards ISO 15901-2 and 9277. In this key comparison, the degrees of equivalence uncertainties for specific adsorption, BET specific surface area, specific pore volume and pore diameter was established. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Nano- to Formation-Scale Estimates of Mineral-Specific Reactive Surface Area

NASA Astrophysics Data System (ADS)

Cole, D. R.; Swift, A.; Sheets, J.; Anovitz, L. M.

2017-12-01

Predictions of changes in fluid composition, coupled with the evolution of the solid matrix, include the generation and testing of reactive transport models. However, translating a heterogeneous natural system into physical and chemical model parameters, including the critical but poorly-constrained metric of fluid-accessible surface area, continues to challenge Earth scientists. Studies of carbon storage capacity, permeability, rock strain due to mineral dissolution and precipitation, or the prediction of rock evolution through diagenesis and weathering each consider macroscale outcomes of processes that often are critically impacted by rock surface geometry at the nanoscale. The approach taken here is to consider the whole vertical extent of a saline reservoir and then to address two questions. First, what is the accessible surface area for each major mineral, and for all adjacent pore sizes from <2 nm on up, within each major lithofacies in that formation? Second, with the formation thus divided into units of analysis, parameterized, and placed into geologic context, what constraints can be placed on reactive surface area as a function of mineral composition? A complex sandstone covering a substantial fraction of the quartz-K-feldspar-illite ternary is selected and mineral-specific surface area quantified using neutron scattering, nitrogen and mercury porosimetry, multi-signal high-resolution mineral mapping, and other techniques. For neutron scattering, scale-specific pore geometries enable more accurate translation of volume into surface area. By applying this workflow to all end-member lithologies of this reservoir formation, equations and maps of surface area as a function of position on a quartz-feldspar-clay ternary plot are developed for each major mineral. Results from this work therefore advance our ability to parameterize models not just for the particular formation studied, but for similar geologic units as well.

São Paulo urban heat islands have a higher incidence of dengue than other urban areas.

PubMed

Araujo, Ricardo Vieira; Albertini, Marcos Roberto; Costa-da-Silva, André Luis; Suesdek, Lincoln; Franceschi, Nathália Cristina Soares; Bastos, Nancy Marçal; Katz, Gizelda; Cardoso, Vivian Ailt; Castro, Bronislawa Ciotek; Capurro, Margareth Lara; Allegro, Vera Lúcia Anacleto Cardoso

2015-01-01

Urban heat islands are characterized by high land surface temperature, low humidity, and poor vegetation, and considered to favor the transmission of the mosquito-borne dengue fever that is transmitted by the Aedes aegypti mosquito. We analyzed the recorded dengue incidence in Sao Paulo city, Brazil, in 2010-2011, in terms of multiple environmental and socioeconomic variables. Geographical information systems, thermal remote sensing images, and census data were used to classify city areas according to land surface temperature, vegetation cover, population density, socioeconomic status, and housing standards. Of the 7415 dengue cases, a majority (93.1%) mapped to areas with land surface temperature >28°C. The dengue incidence rate (cases per 100,000 inhabitants) was low (3.2 cases) in high vegetation cover areas, but high (72.3 cases) in low vegetation cover areas where the land surface temperature was 29±2°C. Interestingly, a multiple cluster analysis phenogram showed more dengue cases clustered in areas of land surface temperature >32°C, than in areas characterized as low socioeconomic zones, high population density areas, or slum-like areas. In laboratory experiments, A. aegypti mosquito larval development, blood feeding, and oviposition associated positively with temperatures of 28-32°C, indicating these temperatures to be favorable for dengue transmission. Thus, among all the variables studied, dengue incidence was most affected by the temperature. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

Partitioning coefficients of polycyclic aromatic hydrocarbons in stack gas from a municipal incinerator

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

Lee, W.M.G.; Chen, J.C.

1995-12-31

In this study, solid-gas partitioning coefficients of PAHs on fly ash in stack gas from a municipal incinerator were determined according to elution analysis with gas-solid chromatography. The fly ash from the electrostatic precipitator was sieved and packed into a 1/4 inch (6.3 mm) pyrex column. Elution analysis with gas-solid chromatography was conducted for three PAEs, Napthalene, Anthracene, and Pyrene. The temperature for elution analysis was in the range of 100{degrees}C to 300{degrees}C. Vg, specific retention volume obtained from elution analysis, and S, specific surface area of fly ash measured by a surface area measurement instrument were used to estimatemore » the solid-gas partitioning coefficient KR. In addition, the relationships between KR and temperature and KR and PAH concentrations were investigated.« less

Changing surface-atmosphere energy exchange and refreezing capacity of the lower accumulation area, West Greenland

NASA Astrophysics Data System (ADS)

Charalampidis, C.; van As, D.; Box, J. E.; van den Broeke, M. R.; Colgan, W. T.; Doyle, S. H.; Hubbard, A. L.; MacFerrin, M.; Machguth, H.; Smeets, C. J. P. P.

2015-11-01

We present 5 years (2009-2013) of automatic weather station measurements from the lower accumulation area (1840 m a.s.l. - above sea level) of the Greenland ice sheet in the Kangerlussuaq region. Here, the summers of 2010 and 2012 were both exceptionally warm, but only 2012 resulted in a strongly negative surface mass budget (SMB) and surface meltwater run-off. The observed run-off was due to a large ice fraction in the upper 10 m of firn that prevented meltwater from percolating to available pore volume below. Analysis reveals an anomalously low 2012 summer-averaged albedo of 0.71 (typically ~ 0.78), as meltwater was present at the ice sheet surface. Consequently, during the 2012 melt season, the ice sheet surface absorbed 28 % (213 MJ m-2) more solar radiation than the average of all other years. A surface energy balance model is used to evaluate the seasonal and interannual variability of all surface energy fluxes. The model reproduces the observed melt rates as well as the SMB for each season. A sensitivity analysis reveals that 71 % of the additional solar radiation in 2012 was used for melt, corresponding to 36 % (0.64 m) of the 2012 surface lowering. The remaining 64 % (1.14 m) of surface lowering resulted from high atmospheric temperatures, up to a +2.6 °C daily average, indicating that 2012 would have been a negative SMB year at this site even without the melt-albedo feedback. Longer time series of SMB, regional temperature, and remotely sensed albedo (MODIS) show that 2012 was the first strongly negative SMB year, with the lowest albedo, at this elevation on record. The warm conditions of recent years have resulted in enhanced melt and reduction of the refreezing capacity in the lower accumulation area. If high temperatures continue, the current lower accumulation area will turn into a region with superimposed ice in coming years.

Finite element analysis on influence of implant surface treatments, connection and bone types.

PubMed

Santiago Junior, Joel Ferreira; Verri, Fellippo Ramos; Almeida, Daniel Augusto de Faria; de Souza Batista, Victor Eduardo; Lemos, Cleidiel Aparecido Araujo; Pellizzer, Eduardo Piza

2016-06-01

The aim of this study is to assess the effect of different dental implant designs, bone type, loading, and surface treatment on the stress distribution around the implant by using the 3D finite-element method. Twelve 3D models were developed with Invesalius 3.0, Rhinoceros 4.0, and Solidworks 2010 software. The analysis was processed using the FEMAP 10.2 and NeiNastran 10.0 software. The applied oblique forces were 200 N and 100 N. The results were analyzed using maps of maximum principal stress and bone microstrain. Statistical analysis was performed using ANOVA and Tukey's test. The results showed that the Morse taper design was most efficient in terms of its distribution of stresses (p<0.05); the external hexagon with platform switching did not show a significant difference from an external hexagon with a standard platform (p>0.05). The different bone types did not show a significant difference in the stress/strain distribution (p>0.05). The surface treatment increased areas of stress concentration under axial loading (p<0.05) and increased areas of microstrain under axial and oblique loading (p<0.05) on the cortical bone. The Morse taper design behaved better biomechanically in relation to the bone tissue. The treated surface increased areas of stress and strain on the cortical bone tissue. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface atomic structure characterization of SnSe and black phosphorus using selected area uLEED-IV via LEEM

NASA Astrophysics Data System (ADS)

Dai, Zhongwei; Grady, Maxwell; Yu, Jiexiang; Zang, Jiadong; Pohl, Karsten; Jin, Wencan; Kim, Young Duck; Hone, James; Dadap, Jerry; Osgood, Richard; Sadowski, Jerzy; Vishwanath, Suresh; Xing, Huili

Selected area diffraction intensity-voltage (μLEED-IV) analysis via low energy electron microscopy (LEEM) has the combined functionality of atomic surface structure determination and μm area selectivity, making it ideal for structural investigations of 2-D materials. SnSe thin films have been predicted and observed to be topological crystalline insulators. Previous studies suggested that SnSe has a preferred Se-terminated surface configuration. Using μLEED-IV, we determined that SnSe has, on the contrary, a stable Sn termination. This surface is stabilized through an oscillatory interlayer relaxation, which agrees with previous DFT predictions. Black phosphorus (BP) has an intrinsic layer-dependent bandgap ranging from 0.3 eV to 2 eV. Previous STM and DFT studies suggested BP surfaces have a buckling of 0.02 Å to 0.06 Å. We experimentally determined that the surface buckling of BP to be near 0.2 Å. We further propose, using DFT calculations, that this large surface buckling is induced by the presence of surface defects. The influence of this surface buckling on the electronic structures of BP is under investigation.

High surface area mesoporous activated carbon-alginate beads for efficient removal of methylene blue.

PubMed

Nasrullah, Asma; Bhat, A H; Naeem, Abdul; Isa, Mohamed Hasnain; Danish, Mohammed

2018-02-01

High surface area mesoporous activated carbon-alginate (AC-alginate) beads were successfully synthesized by entrapping activated carbon powder derived from Mangosteen fruit peel into calcium-alginate beads for methylene blue (MB) removal from aqueous solution. The structure and surface characteristics of AC-alginate beads were analyzed using Fourier transform infra-red (FTIR) spectroscopy, scanning electron microscopy (SEM) and surface area analysis (S BET ), while thermal properties were tested using thermogravimetric analysis (TGA). The effect of AC-alginate dose, pH of solution, contact time, initial concentration of MB solution and temperature on MB removal was elucidated. The results showed that the maximum adsorption capacity of 230mg/g was achieved for 100mg/L of MB solution at pH 9.5 and temperature 25°C. Furthermore, the adsorption of MB on AC-alginate beads followed well pseudo-second order equation and equilibrium adsorption data were better fitted by the Freundlich isotherm model. The findings reveal the feasibility of AC-alginate beads composite to be used as a potential and low cost adsorbent for removal of cationic dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

Sex differences in the relationship between planum temporale asymmetry and corpus callosum morphology in chimpanzees (Pan troglodytes): A combined MRI and DTI analysis.

PubMed

Hopkins, William D; Hopkins, Anna M; Misiura, Maria; Latash, Elitaveta M; Mareno, Mary Catherine; Schapiro, Steven J; Phillips, Kimberley A

2016-12-01

Increases brain size has been hypothesized to be inversely associated with the expression of behavioral and brain asymmetries within and between species. We tested this hypothesis by analyzing the relation between asymmetries in the planum temporale (PT) and different measures of the corpus callosum (CC) including surface area, streamline count as measured from diffusion tensor imaging, fractional anisotropy values and the ratio in the number of fibers to surface area in a sample of chimpanzees. We found that chimpanzees with larger PT asymmetries in absolute terms had smaller CC surface areas, fewer streamlines and a smaller ratio of fibers to surface area. These results were largely specific to male but not female chimpanzees. Our results partially support the hypothesis that brain asymmetries are linked to variation in corpus callosum morphology, although these associations may be sex-dependent. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reciprocal-space and real-space neutron investigation of nanostructured Mo 2C and WC

NASA Astrophysics Data System (ADS)

Page, Katharine; Li, Jun; Savinelli, Robert; Szumila, Holly N.; Zhang, Jinping; Stalick, Judith K.; Proffen, Thomas; Scott, Susannah L.; Seshadri, Ram

2008-11-01

As possible substitute materials for platinum group metal heterogeneous catalysts, high surface area carbides of the early transition metals Mo and W are of great interest. Here we report nanostructured, high surface area Mo 2C and WC prepared by decomposing and carburizing ammonium paramolybdate [(NH 4) 6Mo 7O 24·4H 2O] and ammonium paratungstate [(NH 4) 10W 12O 41·5H 2O] in flowing 50%CH 4/50%H 2. Surface areas as high as 52 m 2/g for Mo 2C and 24 m 2/g for WC were obtained, with both structures crystallizing in structures appropriate for catalytic activity. We have studied these materials using a combination of neutron diffraction Rietveld refinement, X-ray photoelectron spectroscopy, surface area measurements, and scanning transmission electron microscopy. In addition, we have used pair-distribution function (PDF) analysis of the neutron total scattering data as a means of establishing the presence of graphitic carbon in the as-prepared materials.

INTERFRAGMENTARY SURFACE AREA AS AN INDEX OF COMMINUTION SEVERITY IN CORTICAL BONE IMPACT

PubMed Central

Beardsley, Christina L.; Anderson, Donald D.; Marsh, J. Lawrence; Brown, Thomas D.

2008-01-01

Summary A monotonic relationship is expected between energy absorption and fracture surface area generation for brittle solids, based on fracture mechanics principles. It was hypothesized that this relationship is demonstrable in bone, to the point that on a continuous scale, comminuted fractures created with specific levels of energy delivery could be discriminated from one another. Using bovine cortical bone segments in conjunction with digital image analysis of CT fracture data, the surface area freed by controlled impact fracture events was measured. The results demonstrated a statistically significant (p<0.0001) difference in measured de novo surface area between three specimen groups, over a range of input energies from 0.423 to 0.702 J/g. Local material properties were also incorporated into these measurements via CT Hounsfield intensities. This study confirms that comminution severity of bone fractures can indeed be measured on a continuous scale, based on energy absorption. This lays a foundation for similar assessments in human injuries. PMID:15885492

Comparative analysis of different underlying surfaces using a high-resolution assimilation dataset in semi-arid areas in China

NASA Astrophysics Data System (ADS)

Ruan, Jinshuai; Wen, Xiaohang; Fan, Guangzhou; Li, Deqin; Hua, Wei; Wang, Bingyun; Zhang, Yi; Zhang, Mingjun; Wang, Chao; Wang, Lei

2017-11-01

To study the land surface and atmospheric meteorological characteristics of non-uniform underlying surfaces in the semi-arid area of Northeast China, we use a "High-Resolution Assimilation Dataset of the water-energy cycle in China (HRADC)". The grid points of three different underlying surfaces were selected, and their meteorological elements were averaged for each type (i.e., mixed forest, grassland, and cropland). For 2009, we compared and analyzed the different components of leaf area index (LAI), soil temperature and moisture, surface albedo, precipitation, and surface energy for various underlying surfaces in Northeast China. The results indicated that the LAI of mixed forest and cropland during the summer is greater than 5 m2 m-2 and below 2.5 m2 m-2 for grassland; in the winter and spring seasons, the Green Vegetation Fraction (GVF) is below 30%. The soil temperature and moisture both vary greatly. Throughout the year, the mixed forest is dominated by latent heat evaporation; in grasslands and croplands, the sensible heat flux and the latent heat flux are approximately equal, and the GVF contributed more to latent heat flux than sensible heat flux in the summer. This study compares meteorological characteristics between three different underlying surfaces of the semi-arid area of Northeast China and makes up for the insufficiency of purely using observations for the study. This research is important for understanding the water-energy cycle and transport in the semi-arid area.

Landslide hazard mapping with selected dominant factors: A study case of Penang Island, Malaysia

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

Tay, Lea Tien; Alkhasawneh, Mutasem Sh.; Ngah, Umi Kalthum

Landslide is one of the destructive natural geohazards in Malaysia. In addition to rainfall as triggering factos for landslide in Malaysia, topographical and geological factors play important role in the landslide susceptibility analysis. Conventional topographic factors such as elevation, slope angle, slope aspect, plan curvature and profile curvature have been considered as landslide causative factors in many research works. However, other topographic factors such as diagonal length, surface area, surface roughness and rugosity have not been considered, especially for the research work in landslide hazard analysis in Malaysia. This paper presents landslide hazard mapping using Frequency Ratio (FR) and themore » study area is Penang Island of Malaysia. Frequency ratio approach is a variant of probabilistic method that is based on the observed relationships between the distribution of landslides and each landslide-causative factor. Landslide hazard map of Penang Island is produced by considering twenty-two (22) landslide causative factors. Among these twenty-two (22) factors, fourteen (14) factors are topographic factors. They are elevation, slope gradient, slope aspect, plan curvature, profile curvature, general curvature, tangential curvature, longitudinal curvature, cross section curvature, total curvature, diagonal length, surface area, surface roughness and rugosity. These topographic factors are extracted from the digital elevation model of Penang Island. The other eight (8) non-topographic factors considered are land cover, vegetation cover, distance from road, distance from stream, distance from fault line, geology, soil texture and rainfall precipitation. After considering all twenty-two factors for landslide hazard mapping, the analysis is repeated with fourteen dominant factors which are selected from the twenty-two factors. Landslide hazard map was segregated into four categories of risks, i.e. Highly hazardous area, Hazardous area, Moderately hazardous area and Not hazardous area. The maps was assessed using ROC (Rate of Curve) based on the area under the curve method (AUC). The result indicates an increase of accuracy from 77.76% (with all 22 factors) to 79.00% (with 14 dominant factors) in the prediction of landslide occurrence.« less

GC/MS analysis of pesticides in the Ferrara area (Italy) surface water: a chemometric study.

PubMed

Pasti, Luisa; Nava, Elisabetta; Morelli, Marco; Bignami, Silvia; Dondi, Francesco

2007-01-01

The development of a network to monitor surface waters is a critical element in the assessment, restoration and protection of water quality. In this study, concentrations of 42 pesticides--determined by GC-MS on samples from 11 points along the Ferrara area rivers--have been analyzed by chemometric tools. The data were collected over a three-year period (2002-2004). Principal component analysis of the detected pesticides was carried out in order to define the best spatial locations for the sampling points. The results obtained have been interpreted in view of agricultural land use. Time series data regarding pesticide contents in surface waters has been analyzed using the Autocorrelation function. This chemometric tool allows for seasonal trends and makes it possible to optimize sampling frequency in order to detect the effective maximum pesticide content.

An analysis of sitting areas and pressures of man.

DOT National Transportation Integrated Search

1962-01-01

Studies of sitting area on a plane rigid surface for a group of 104 male subjects were made. Area was found to vary with height and weight and to increase with age up to 40 years after which there is a steady decline. Means were 179.4 sq. in. for are...

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.

Dynamic factor modeling of ground and surface water levels in an agricultural area adjacent to Everglades National Park

NASA Astrophysics Data System (ADS)

Ritter, A.; Muñoz-Carpena, R.

2006-02-01

The extensive eastern boundary of Everglades National Park (ENP) in south Florida (USA) is subject to one the most expensive and ambitious environmental restoration projects in history. Understanding and predicting the interaction between the shallow aquifer and surface water is a key component for fine-tuning the process. The Frog Pond is an intensively instrumented agricultural 2023 ha area adjacent to ENP. The interactions among 21 multivariate daily time series (ground and surface water elevations, rainfall and evapotranspiration) available from this area were studied by means of dynamic factor analysis, a novel technique in the field of hydrology. This method is designed to determine latent or background effects governing variability or fluctuations in non-stationary time series. Water levels in 16 wells and two drainage ditch locations inside the area were selected as response variables, and canal levels and net recharge as explanatory variables. Elevations in the two canals delimiting the Frog Pond area were found to be the main factors explaining the response variables. This influence of canal elevations on water levels inside the area was complementary and inversely related to the distance between the observation point and each canal. Rainfall events do not affect daily water levels significantly but are responsible for instantaneous or localized groundwater responses that in some cases can be directly associated with the risk of flooding. This close coupling between surface and groundwater levels, that corroborates that found by other authors using different methods, could hinder on-going environmental restoration efforts in the area by bypassing the function of wetlands and other surface features. An empirical model with a reduced set of parameters was successfully developed and validated in the area by interpolating the results from the dynamic factor analysis across the spatial domain (coefficient of efficiency across the domain: 0.66-0.99). Although specific to the area, the resulting model is deemed useful for water management within the wide range of conditions similar to those present during the experimental period.

Refined methods of aeroelastic analysis and optimization. [swept wings, propeller theory, and subsonic flutter

NASA Technical Reports Server (NTRS)

Ashley, H.

1984-01-01

Graduate research activity in the following areas is reported: the divergence of laminated composite lifting surfaces, subsonic propeller theory and aeroelastic analysis, and cross sectional resonances in wind tunnels.

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

Jomekian, A.; Faculty of Chemical Engineering, Iran University of Science and Technology; Behbahani, R.M., E-mail: behbahani@put.ac.ir

Ultra porous ZIF-8 particles synthesized using PEO/PA6 based poly(ether-block-amide) (Pebax 1657) as structure directing agent. Structural properties of ZIF-8 samples prepared under different synthesis parameters were investigated by laser particle size analysis, XRD, N{sub 2} adsorption analysis, BJH and BET tests. The overall results showed that: (1) The mean pore size of all ZIF-8 samples increased remarkably (from 0.34 nm to 1.1–2.5 nm) compared to conventionally synthesized ZIF-8 samples. (2) Exceptional BET surface area of 1869 m{sup 2}/g was obtained for a ZIF-8 sample with mean pore size of 2.5 nm. (3) Applying high concentrations of Pebax 1657 to themore » synthesis solution lead to higher surface area, larger pore size and smaller particle size for ZIF-8 samples. (4) Both, Increase in temperature and decrease in molar ratio of MeIM/Zn{sup 2+} had increasing effect on ZIF-8 particle size, pore size, pore volume, crystallinity and BET surface area of all investigated samples. - Highlights: • The pore size of ZIF-8 samples synthesized with Pebax 1657 increased remarkably. • The BET surface area of 1869 m{sup 2}/gr obtained for a ZIF-8 synthesized sample with Pebax. • Increase in temperature had increasing effect on textural properties of ZIF-8 samples. • Decrease in MeIM/Zn{sup 2+} had increasing effect on textural properties of ZIF-8 samples.« less

Volume and contact surface area analysis of bony tunnels in single and double bundle anterior cruciate ligament reconstruction using autograft tendons: in vivo three-dimensional imaging analysis.

PubMed

Yang, Jae-Hyuk; Chang, Minho; Kwak, Dai-Soon; Wang, Joon Ho

2014-09-01

Regarding reconstruction surgery of the anterior cruciate ligament (ACL), there is still a debate whether to perform a single bundle (SB) or double bundle (DB) reconstruction. The purpose of this study was to analyze and compare the volume and surface area of femoral and tibial tunnels during transtibial SB versus transportal DB ACL reconstruction. A consecutive series of 26 patients who underwent trantibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft from January 2010 to October 2010 were included in this study. Three-dimensional computed tomography (3D-CT) was taken within one week after operation. The CT bone images were segmented with use of Mimics software v14.0. The obtained digital images were then imported in the commercial package Geomagic Studio v10.0 and SketchUp Pro v8.0 for processing. The femoral and tibial tunnel lengths, diameters, volumes and surface areas were evaluated. A comparison between the two groups was performed using the independent-samples t-test. A p-value less than the significance value of 5% (p < 0.05) was considered statistically significant. Regarding femur tunnels, a significant difference was not found between the tunnel volume for SB technique (1,496.51 ± 396.72 mm(3)) and the total tunnel volume for DB technique (1,593.81 ± 469.42 mm(3); p = 0.366). However, the total surface area for femoral tunnels was larger in DB technique (919.65 ± 201.79 mm(2)) compared to SB technique (810.02 ± 117.98 mm(2); p = 0.004). For tibia tunnels, there was a significant difference between tunnel volume for the SB technique (2,070.43 ± 565.07 mm(3)) and the total tunnel volume for the DB technique (2,681.93 ± 668.09 mm(3); p ≤ 0.001). The tibial tunnel surface area for the SB technique (958.84 ± 147.50 mm(2)) was smaller than the total tunnel surface area for the DB technique (1,493.31 ± 220.79 mm(2); p ≤ 0.001). Although the total femoral tunnel volume was similar between two techniques, the total surface area was larger in the DB technique. For the tibia, both total tunnel volume and the surface area were larger in DB technique.

Retinotopic Maps, Spatial Tuning, and Locations of Human Visual Areas in Surface Coordinates Characterized with Multifocal and Blocked fMRI Designs

PubMed Central

Henriksson, Linda; Karvonen, Juha; Salminen-Vaparanta, Niina; Railo, Henry; Vanni, Simo

2012-01-01

The localization of visual areas in the human cortex is typically based on mapping the retinotopic organization with functional magnetic resonance imaging (fMRI). The most common approach is to encode the response phase for a slowly moving visual stimulus and to present the result on an individual's reconstructed cortical surface. The main aims of this study were to develop complementary general linear model (GLM)-based retinotopic mapping methods and to characterize the inter-individual variability of the visual area positions on the cortical surface. We studied 15 subjects with two methods: a 24-region multifocal checkerboard stimulus and a blocked presentation of object stimuli at different visual field locations. The retinotopic maps were based on weighted averaging of the GLM parameter estimates for the stimulus regions. In addition to localizing visual areas, both methods could be used to localize multiple retinotopic regions-of-interest. The two methods yielded consistent retinotopic maps in the visual areas V1, V2, V3, hV4, and V3AB. In the higher-level areas IPS0, VO1, LO1, LO2, TO1, and TO2, retinotopy could only be mapped with the blocked stimulus presentation. The gradual widening of spatial tuning and an increase in the responses to stimuli in the ipsilateral visual field along the hierarchy of visual areas likely reflected the increase in the average receptive field size. Finally, after registration to Freesurfer's surface-based atlas of the human cerebral cortex, we calculated the mean and variability of the visual area positions in the spherical surface-based coordinate system and generated probability maps of the visual areas on the average cortical surface. The inter-individual variability in the area locations decreased when the midpoints were calculated along the spherical cortical surface compared with volumetric coordinates. These results can facilitate both analysis of individual functional anatomy and comparisons of visual cortex topology across studies. PMID:22590626

High Surface Area of Porous Silicon Drives Desorption of Intact Molecules

PubMed Central

Northen, Trent R.; Woo, Hin-Koon; Northen, Michael T.; Nordström, Anders; Uritboonthail, Winnie; Turner, Kimberly L.; Siuzdak, Gary

2007-01-01

The surface structure of porous silicon used in desorption/ionization on porous silicon (DIOS) mass analysis is known to play a primary role in the desorption/ionization (D/I) process. In this study, mass spectrometry and scanning electron microscopy (SEM) are used to examine the correlation between intact ion generation with surface ablation, and surface morphology. The DIOS process is found to be highly laser energy dependent and correlates directly with the appearance of surface ions (Sin+ and OSiH+). A threshold laser energy for DIOS is observed (10 mJ/cm2), which supports that DIOS is driven by surface restructuring and is not a strictly thermal process. In addition, three DIOS regimes are observed which correspond to surface restructuring and melting. These results suggest that higher surface area silicon substrates may enhance DIOS performance. A recent example which fits into this mechanism is silicon nanowires surface which have a high surface energy and concomitantly requires lower laser energy for analyte desorpton. PMID:17881245

The use of ERTS/LANDSAT imagery in relation to airborne remote sensing for terrain analysis in western Queensland, Australia

NASA Technical Reports Server (NTRS)

Cole, M. M. (Principal Investigator); Owen-Jones, S.

1976-01-01

The author has identified the following significant results. Distinctive spectral signatures were found associated with areas of near surface bedrock with covered ground east of Dugald River and along the Thorntonia River valley west of Lady Annie. Linears identified in the Dugald River area on LANDSAT 2 imagery taken in March and July 1975 over the Cloncurry-Dobbyn area, displayed preferred orientation. A linear group with NE-SW orientation was identified in the Lady Annie area. In this area, the copper mineralization in the Mt. Kelly area occurs along a well marked linear with NNW/SSE direction apparent on images for March, September, and November 1975. Geobotanical anomalies provided surface expression of the copper deposits in Mt. Kelley.

NCEP SST Analysis

Science.gov Websites

Branches Global Climate & Weather Modeling Mesoscale Modeling Marine Modeling and Analysis Contact EMC , state and local government Web resources and services. Real-time, global, sea surface temperature (RTG_SST_HR) analysis For a regional map, click the desired area in the global SST analysis and anomaly maps

Surface structure of bulk 2H-MoS2(0001) and exfoliated suspended monolayer MoS2: A selected area low energy electron diffraction study

NASA Astrophysics Data System (ADS)

Dai, Zhongwei; Jin, Wencan; Grady, Maxwell; Sadowski, Jerzy T.; Dadap, Jerry I.; Osgood, Richard M.; Pohl, Karsten

2017-06-01

We have used selected area low energy electron diffraction intensity-voltage (μLEED-IV) analysis to investigate the surface structure of crystalline 2H molybdenum disulfide (MoS2) and mechanically exfoliated and suspended monolayer MoS2. Our results show that the surface structure of bulk 2H-MoS2 is distinct from its bulk and that it has a slightly smaller surface relaxation at 320 K than previously reported at 95 K. We concluded that suspended monolayer MoS2 shows a large interlayer relaxation compared to the MoS2 sandwich layer terminating the bulk surface. The Debye temperature of MoS2 was concluded to be about 600 K, which agrees with a previous theoretical study. Our work has shown that the dynamical μLEED-IV analysis performed with a low energy electron microscope (LEEM) is a powerful technique for determination of the local atomic structures of currently extensively studied two-dimensional (2-D) materials.

Surface structure of bulk 2H-MoS 2 (0001) and exfoliated suspended monolayer MoS 2 : A selected area low energy electron diffraction study

DOE PAGES

Dai, Zhongwei; Jin, Wencan; Grady, Maxwell; ...

2017-02-10

Here, we used selected area low energy electron diffraction intensity-voltage (μLEED-IV) analysis to investigate the surface structure of crystalline 2H molybdenum disulfide (MoS 2) and mechanically exfoliated and suspended monolayer MoS 2. Our results show that the surface structure of bulk 2H-MoS 2 is distinct from its bulk and that it has a slightly smaller surface relaxation at 320 K than previously reported at 95 K. We concluded that suspended monolayer MoS 2 shows a large interlayer relaxation compared to the MoS 2 sandwich layer terminating the bulk surface. The Debye temperature of MoS 2 was concluded to be aboutmore » 600 K, which agrees with a previous theoretical study. Our work has shown that the dynamical μLEED-IV analysis performed with a low energy electron microscope (LEEM) is a powerful technique for determination of the local atomic structures of currently extensively studied two-dimensional (2-D) materials.« less

Spatial and Temporal Variation of Land Surface Temperature in Fujian Province from 2001 TO 2015

NASA Astrophysics Data System (ADS)

Li, Y.; Wang, X.; Ding, Z.

2018-04-01

Land surface temperature (LST) is an essential parameter in the physics of land surface processes. The spatiotemporal variations of LST on the Fujian province were studied using AQUA Moderate Resolution Imaging Spectroradiometer LST data. Considering the data gaps in remotely sensed LST products caused by cloud contamination, the Savitzky-Golay (S-G) filter method was used to eliminate the influence of cloud cover and to describe the periodical signals of LST. Observed air temperature data from 27 weather stations were employed to evaluate the fitting performance of the S-G filter method. Results indicate that S-G can effectively fit the LST time series and remove the influence of cloud cover. Based on the S-G-derived result, Spatial and temporal Variations of LST in Fujian province from 2001 to 2015 are analysed through slope analysis. The results show that: 1) the spatial distribution of annual mean LST generally exhibits consistency with altitude in the study area and the average of LST was much higher in the east than in the west. 2) The annual mean temperature of LST declines slightly among 15 years in Fujian. 3) Slope analysis reflects the spatial distribution characteristics of LST changing trend in Fujian.Improvement areas of LST are mainly concentrated in the urban areas of Fujian, especially in the eastern urban areas. Apparent descent areas are mainly distributed in the area of Zhangzhou and eastern mountain area.

Characterization of a Louisiana Bay Bottom

NASA Astrophysics Data System (ADS)

Freeman, A. M.; Roberts, H. H.

2016-02-01

This study correlates side-scan sonar and CHIRP water bottom-subbottom acoustic amplitudes with cone penetrometer data to expand the limited understanding of the geotechnical properties of sediments in coastal Louisiana's bays. Standardized analysis procedures were developed to characterize the bay bottom and shallow subsurface of the Sister Lake bay bottom. The CHIRP subbottom acoustic data provide relative amplitude information regarding reflection horizons of the bay bottom and shallow subsurface. An amplitude analysis technique was designed to identify different reflectance regions within the lake from the CHIRP subbottom profile data. This amplitude reflectivity analysis technique provides insight into the relative hardness of the bay bottom and shallow subsurface, useful in identifying areas of erosion versus deposition from storms, as well as areas suitable for cultch plants for state oyster seed grounds, or perhaps other restoration projects. Side-scan and CHIRP amplitude reflectivity results are compared to penetrometer data that quantifies geotechnical properties of surface and near-surface sediments. Initial results indicate distinct penetrometer signatures that characterize different substrate areas including soft bottom, storm-deposited silt-rich sediments, oyster cultch, and natural oyster reef areas. Although amplitude analysis of high resolution acoustic data does not directly quantify the geotechnical properties of bottom sediments, our analysis indicates a close relationship. The analysis procedures developed in this study can be applied in other dynamic coastal environments, "calibrating" the use of synoptic acoustic methods for large-scale water bottom characterization.

The digital step edge

NASA Technical Reports Server (NTRS)

Haralick, R. M.

1982-01-01

The facet model was used to accomplish step edge detection. The essence of the facet model is that any analysis made on the basis of the pixel values in some neighborhood has its final authoritative interpretation relative to the underlying grey tone intensity surface of which the neighborhood pixel values are observed noisy samples. Pixels which are part of regions have simple grey tone intensity surfaces over their areas. Pixels which have an edge in them have complex grey tone intensity surfaces over their areas. Specially, an edge moves through a pixel only if there is some point in the pixel's area having a zero crossing of the second directional derivative taken in the direction of a non-zero gradient at the pixel's center. To determine whether or not a pixel should be marked as a step edge pixel, its underlying grey tone intensity surface was estimated on the basis of the pixels in its neighborhood.

The surface abundance and stratigraphy of lunar rocks from data about their albedo

NASA Technical Reports Server (NTRS)

Shevchenko, V. V.

1977-01-01

The data pf ground-based studies and surveys of the lunar surface by the Zond and Apollo spacecraft have been used to construct an albedo map covering 80 percent of the lunar sphere. Statistical analysis of the distribution of areas with various albedos shows several types of lunar surface. Comparison of albedo data for maria and continental areas with the results of geochemical orbital surveys allows the identification of the types of surface with known types of lunar rock. The aluminum/silcon and magnesium/silicon ratios as measured by the geochemical experiments on the Apollo 15 and Apollo 16 spacecraft were used as an indication of the chemical composition of the rock. The relationship of the relative aluminum content to the age of crystalline rocks allows a direct dependence to be constructed between the mean albedo of areas and the age of the rocks of which they are composed.

User's Manual: Routines for Radiative Heat Transfer and Thermometry

NASA Technical Reports Server (NTRS)

Risch, Timothy K.

2016-01-01

Determining the intensity and spectral distribution of radiation emanating from a heated surface has applications in many areas of science and engineering. Areas of research in which the quantification of spectral radiation is used routinely include thermal radiation heat transfer, infrared signature analysis, and radiation thermometry. In the analysis of radiation, it is helpful to be able to predict the radiative intensity and the spectral distribution of the emitted energy. Presented in this report is a set of routines written in Microsoft Visual Basic for Applications (VBA) (Microsoft Corporation, Redmond, Washington) and incorporating functions specific to Microsoft Excel (Microsoft Corporation, Redmond, Washington) that are useful for predicting the radiative behavior of heated surfaces. These routines include functions for calculating quantities of primary importance to engineers and scientists. In addition, the routines also provide the capability to use such information to determine surface temperatures from spectral intensities and for calculating the sensitivity of the surface temperature measurements to unknowns in the input parameters.

Multichannel analysis of the surface waves of earth materials in some parts of Lagos State, Nigeria

NASA Astrophysics Data System (ADS)

Adegbola, R. B.; Oyedele, K. F.; Adeoti, L.; Adeloye, A. B.

2016-09-01

We present a method that utilizes multichannel analysis of surface waves (MASW), which was used to measure shear wave velocities, with a view to establishing the probable causes of road failure, subsidence and weakening of structures in some local government areas in Lagos, Nigeria. MASW data were acquired using a 24-channel seismograph. The acquired data were processed and transformed into a two-dimensional (2-D) structure reflective of the depth and surface wave velocity distribution within a depth of 0-15 m beneath the surface using SURFSEIS software. The shear wave velocity data were compared with other geophysical/ borehole data that were acquired along the same profile. The comparison and correlation illustrate the accuracy and consistency of MASW-derived shear wave velocity profiles. Rigidity modulus and N-value were also generated. The study showed that the low velocity/ very low velocity data are reflective of organic clay/ peat materials and thus likely responsible for the failure, subsidence and weakening of structures within the study areas.

A new method for the assessment of the surface topography of NiTi rotary instruments.

PubMed

Ferreira, F; Barbosa, I; Scelza, P; Russano, D; Neff, J; Montagnana, M; Zaccaro Scelza, M

2017-09-01

To describe a new method for the assessment of nanoscale alterations in the surface topography of nickel-titanium endodontic instruments using a high-resolution optical method and to verify the accuracy of the technique. Noncontact three-dimensional optical profilometry was used to evaluate defects on a size 25, .08 taper reciprocating instrument (WaveOne ® ), which was subjected to a cyclic fatigue test in a simulated root canal in a clear resin block. For the investigation, an original procedure was established for the analysis of similar areas located 3 mm from the tip of the instrument before and after canal preparation to enable the repeatability and reproducibility of the measurements with precision. All observations and analysis were taken in areas measuring 210 × 210 μm provided by the software of the equipment. The three-dimensional high-resolution image analysis showed clear alterations in the surface topography of the examined cutting blade and flute of the instrument, before and after use, with the presence of surface irregularities such as deformations, debris, grooves, cracks, steps and microcavities. Optical profilometry provided accurate qualitative nanoscale evaluation of similar surfaces before and after the fatigue test. The stability and repeatability of the technique enables a more comprehensive understanding of the effects of wear on the surface of endodontic instruments. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Surface radiant flux densities inferred from LAC and GAC AVHRR data

NASA Astrophysics Data System (ADS)

Berger, F.; Klaes, D.

To infer surface radiant flux densities from current (NOAA-AVHRR, ERS-1/2 ATSR) and future meteorological (Envisat AATSR, MSG, METOP) satellite data, the complex, modular analysis scheme SESAT (Strahlungs- und Energieflüsse aus Satellitendaten) could be developed (Berger, 2001). This scheme allows the determination of cloud types, optical and microphysical cloud properties as well as surface and TOA radiant flux densities. After testing of SESAT in Central Europe and the Baltic Sea catchment (more than 400scenes U including a detailed validation with various surface measurements) it could be applied to a large number of NOAA-16 AVHRR overpasses covering the globe.For the analysis, two different spatial resolutions U local area coverage (LAC) andwere considered. Therefore, all inferred results, like global area coverage (GAC) U cloud cover, cloud properties and radiant properties, could be intercompared. Specific emphasis could be made to the surface radiant flux densities (all radiative balance compoments), where results for different regions, like Southern America, Southern Africa, Northern America, Europe, and Indonesia, will be presented. Applying SESAT, energy flux densities, like latent and sensible heat flux densities could also be determined additionally. A statistical analysis of all results including a detailed discussion for the two spatial resolutions will close this study.

Device and method for enhanced collection and assay of chemicals with high surface area ceramic

DOEpatents

Addleman, Raymond S.; Li, Xiaohong Shari; Chouyyok, Wilaiwan; Cinson, Anthony D.; Bays, John T.; Wallace, Krys

2016-02-16

A method and device for enhanced capture of target analytes is disclosed. This invention relates to collection of chemicals for separations and analysis. More specifically, this invention relates to a solid phase microextraction (SPME) device having better capability for chemical collection and analysis. This includes better physical stability, capacity for chemical collection, flexible surface chemistry and high affinity for target analyte.

Using the Image Analysis Method for Describing Soil Detachment by a Single Water Drop Impact

PubMed Central

Ryżak, Magdalena; Bieganowski, Andrzej

2012-01-01

The aim of the present work was to develop a method based on image analysis for describing soil detachment caused by the impact of a single water drop. The method consisted of recording tracks made by splashed particles on blotting paper under an optical microscope. The analysis facilitated division of the recorded particle tracks on the paper into drops, “comets” and single particles. Additionally, the following relationships were determined: (i) the distances of splash; (ii) the surface areas of splash tracks into relation to distance; (iii) the surface areas of the solid phase transported over a given distance; and (iv) the ratio of the solid phase to the splash track area in relation to distance. Furthermore, the proposed method allowed estimation of the weight of soil transported by a single water drop splash in relation to the distance of the water drop impact. It was concluded that the method of image analysis of splashed particles facilitated analysing the results at very low water drop energy and generated by single water drops.

High-content analysis of single cells directly assembled on CMOS sensor based on color imaging.

PubMed

Tanaka, Tsuyoshi; Saeki, Tatsuya; Sunaga, Yoshihiko; Matsunaga, Tadashi

2010-12-15

A complementary metal oxide semiconductor (CMOS) image sensor was applied to high-content analysis of single cells which were assembled closely or directly onto the CMOS sensor surface. The direct assembling of cell groups on CMOS sensor surface allows large-field (6.66 mm×5.32 mm in entire active area of CMOS sensor) imaging within a second. Trypan blue-stained and non-stained cells in the same field area on the CMOS sensor were successfully distinguished as white- and blue-colored images under white LED light irradiation. Furthermore, the chemiluminescent signals of each cell were successfully visualized as blue-colored images on CMOS sensor only when HeLa cells were placed directly on the micro-lens array of the CMOS sensor. Our proposed approach will be a promising technique for real-time and high-content analysis of single cells in a large-field area based on color imaging. Copyright © 2010 Elsevier B.V. All rights reserved.

Analyzing Visibility Configurations.

PubMed

Dachsbacher, C

2011-04-01

Many algorithms, such as level of detail rendering and occlusion culling methods, make decisions based on the degree of visibility of an object, but do not analyze the distribution, or structure, of the visible and occluded regions across surfaces. We present an efficient method to classify different visibility configurations and show how this can be used on top of existing methods based on visibility determination. We adapt co-occurrence matrices for visibility analysis and generalize them to operate on clusters of triangular surfaces instead of pixels. We employ machine learning techniques to reliably classify the thus extracted feature vectors. Our method allows perceptually motivated level of detail methods for real-time rendering applications by detecting configurations with expected visual masking. We exemplify the versatility of our method with an analysis of area light visibility configurations in ray tracing and an area-to-area visibility analysis suitable for hierarchical radiosity refinement. Initial results demonstrate the robustness, simplicity, and performance of our method in synthetic scenes, as well as real applications.

On-Plate Self-Desalting and Matrix-Free LDI MS Analysis of Peptides With a Surface Patterned Sample Support

NASA Astrophysics Data System (ADS)

Zeng, Zhoufang; Wang, Yandong; Guo, Xinhua; Wang, Ling; Lu, Nan

2014-05-01

A hydrophobic-hydrophilic-hydrophobic pattern has been produced on the surface of a silicon substrate for selective enrichment, self-desalting, and matrix-free analysis of peptides in a single step. Upon sample application, the sample solution is first confined in a small area by a hydrophobic F-SAM outer area, after which salt contaminants and peptides are selectively enriched in the hydrophilic and hydrophobic areas, respectively. Simultaneously, matrix background noise is significantly reduced or eliminated because of immobilization of matrix molecules. As a result, the detection sensitivity is enhanced 20-fold compared with that obtained using the usual MALDI plate, and interference-free detection is achieved in the low m/z range. In addition, peptide ions can be identified unambiguously in the presence of NH4HCO3 (100 mM), urea (1 M), and NaCl (1 M). When the device was applied to the analysis of BSA digests, the peptide recovery and protein identification confidence were greatly improved.

Analysis of Surface and Subsurface Damage Morphology in Rotary Ultrasonic Machining of BK7 Glass

NASA Astrophysics Data System (ADS)

Hong-xiang, Wang; Chu, Wang; Jun-liang, Liu; Shi, Gao; Wen-Jie, Zhai

2017-11-01

This paper investigates the formation process of surface/subsurface damage in the rotary ultrasonic machining of BK7 glass. The results show that during the milling using the end face of the tool, the cutting depth and the residual height between the abrasive grains constantly change with the high-frequency vibration, generating lots of cracks on both sides of the scratches. The high-frequency vibration accelerates the chips falling from the surface, so that the chips and thermal damage are reduced, causing the grinding surface quality better. A plastic deformation area is formed during the grinding, due to the non-uniform cutting force on the material surface, and the residual stress is produced in the deformation area, inducing the median/lateral cracks.

Histopathological Validation of the Surface-Intermediate-Base Margin Score for Standardized Reporting of Resection Technique during Nephron Sparing Surgery.

PubMed

Minervini, Andrea; Campi, Riccardo; Kutikov, Alexander; Montagnani, Ilaria; Sessa, Francesco; Serni, Sergio; Raspollini, Maria Rosaria; Carini, Marco

2015-10-01

The surface-intermediate-base margin score is a novel standardized reporting system of resection techniques during nephron sparing surgery. We validated the surgeon assessed surface-intermediate-base score with microscopic histopathological assessment of partial nephrectomy specimens. Between June and August 2014 data were prospectively collected from 40 consecutive patients undergoing nephron sparing surgery. The surface-intermediate-base score was assigned to all cases. The score specific areas were color coded with tissue margin ink and sectioned for histological evaluation of healthy renal margin thickness. Maximum, minimum and mean thickness of healthy renal margin for each score specific area grade (surface [S] = 0, S = 1 ; intermediate [I] or base [B] = 0, I or B = 1, I or B = 2) was reported. The Mann-Whitney U and Kruskal-Wallis tests were used to compare the thickness of healthy renal margin in S = 0 vs 1 and I or B = 0 vs 1 vs 2 grades, respectively. Maximum, minimum and mean thickness of healthy renal margin was significantly different among score specific area grades S = 0 vs 1, and I or B = 0 vs 1, 0 vs 2 and 1 vs 2 (p <0.001). The main limitations of the study are the low number of the I or B = 1 and I or B = 2 samples and the assumption that each microscopic slide reflects the entire score specific area for histological analysis. The surface-intermediate-base scoring method can be readily harnessed in real-world clinical practice and accurately mirrors histopathological analysis for quantification and reporting of healthy renal margin thickness removed during tumor excision. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Investigating failure behavior and origins under supposed "shear bond" loading.

PubMed

Sultan, Hassam; Kelly, J Robert; Kazemi, Reza B

2015-07-01

This study evaluated failure behavior when resin-composite cylinders bonded to dentin fractured under traditional "shear" testing. Failure was assessed by scaling of failure loads to changes in cylinder radii and fracture surface analysis. Three stress models were examined including failure by: bonded area; flat-on-cylinder contact; and, uniformly-loaded, cantilevered-beam. Nine 2-mm dentin occlusal dentin discs for each radii tested were embedded in resin and bonded to resin-composite cylinders; radii (mm)=0.79375; 1.5875; 2.38125; 3.175. Samples were "shear" tested at 1.0mm/min. Following testing, disks were finished with silicone carbide paper (240-600grit) to remove residual composite debris and tested again using different radii. Failure stresses were calculated for: "shear"; flat-on-cylinder contact; and, bending of a uniformly-loaded cantilevered beam. Stress equations and constants were evaluated for each model. Fracture-surface analysis was performed. Failure stresses calculated as flat-on-cylinder contact scaled best with its radii relationship. Stress equation constants were constant for failure from the outside surface of the loaded cylinders and not with the bonded surface area or cantilevered beam. Contact failure stresses were constant over all specimen sizes. Fractography reinforced that failures originated from loaded cylinder surface and were unrelated to the bonded surface area. "Shear bond" testing does not appear to test the bonded interface. Load/area "stress" calculations have no physical meaning. While failure is related to contact stresses, the mechanism(s) likely involve non-linear damage accumulation, which may only indirectly be influenced by the interface. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Novel use of a Dektak 150 surface profiler unmasks differences in resorption pit profiles between control and Charcot patient osteoclasts.

PubMed

Petrova, Nina L; Petrov, Peter K; Edmonds, Michael E; Shanahan, Catherine M

2014-04-01

We hypothesized that newly formed osteoclasts from patients with acute Charcot osteoarthropathy can resorb surfaces of bone more extensively compared with controls. Peripheral blood monocytes, isolated from eight Charcot patients and nine controls, were cultured in vitro on 24-well plates and bovine bone discs in duplicate with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor κβ ligand (RANKL). Osteoclast formation was assessed by tartrate-resistant acid phosphatase staining (TRAcP) at day 17. Resorption was measured at day 21 after toluidine blue staining by two methods: (1) area of resorption at the surface by image analysis (%) and (2) area of resorption under the surface (μm(2)) measured by a Dektak 150 Surface Profiler. Ten 1,000 μm-long scans were performed per disc. Pits were classified as unidented, bidented, and multidented according to their shape. Although the number of newly formed TRAcP positive multinucleated cells (>3 nuclei) was similar in M-CSF + RANKL-treated cultures between controls and Charcot patients, the latter exhibited increased resorbing activity. The area of resorption on the surface by image analysis was significantly greater in Charcot patients compared with controls (21.1 % [14.5-26.2] vs. 40.8 % [35.4-46.0], median [25-75th percentile], p < 0.01), as was the area of resorption under the surface (2.7 x 10(3) μm(2) [1.6 x 10(3)- 3.9 x 10(3)] vs. 8.3 x 10(3) μm (2) [5.6 x 10(3)- 10.6 x 10(3), [corrected] p < 0.01) after profilometry. In Charcot patients pits were deeper and wider and more frequently presented as multidented pits. This application of the Dektak 150 Surface Profiler revealed novel differences in resorption pit profile from osteoclasts derived from Charcot patients compared with controls. Resorption in Charcot patients was mediated by highly aggressive newly formed osteoclasts from monocytes eroding large and deep areas of bone.

Evaluation of the Surface Treatment on Bone Healing in a Transmucosal 1-mm Area of Implant Abutment: An Experimental Study in the Rabbit Tibia.

PubMed

Gehrke, Sergio Alexandre; da Silva Neto, Ulisses Tavares

2016-06-01

The objective of the present study was to investigate the effect on bone tissue healing patterns in 1-mm area treated in the transmucosal surface of the abutment in the tibia of rabbits. Forty-six abutments were divided into two groups: control group (CG) with 14 abutments with smooth surface and experimental group (EG) with 32 abutments presenting a 1-mm area of the transmucosal surface treated through sandblasting with microparticles of titanium oxide followed by acid etching. Five samples of each group were analyzed using an optical laser profilometer for surface roughness characterization. Thirty-six Morse taper implants (3.5 mm in diameter and 7 mm in length) were inserted 1.5 mm subcrestal into the tibiae of nine rabbits. The implants were removed after 8, 10, and 12 weeks for histological analysis. The histological slides were prepared and analyzed qualitatively in relation to the new bone at the interface bone-abutment and quantitatively, in relation to bone height from the base of the implant. These data were computed and statistically compared inside the groups using analysis of variance and the U-test between groups for same time. Both groups exhibited bone growth in the direction and over the surface of the abutments, with good healing. However, the EG group showed an increased height of bone formation in the crestal direction, and highly significant differences were observed (p < .001) between these measured values. Under the limitations of the present study, histological follow-up at 8, 10, and 12 weeks showed that transmucosal 1-mm area of implant abutment with treatment of the surface facilitated the maintenance of bone height around the abutment compared with the same abutment with the totally smooth surface. © 2015 Wiley Periodicals, Inc.

Can static foot posture measurements predict regional plantar surface area?

PubMed

McPoil, Thomas G; Haager, Mathew; Hilt, John; Klapheke, John; Martinez, Ray; VanSteenwyk, Cory; Weber, Nicholas; Cornwall, Mark W; Bade, Michael

2014-12-01

The intent of this study was to determine if the use of a single or combination of static foot posture measurements can be used to predict rearfoot, midfoot, and forefoot plantar surface area in individuals with pronated or normal foot types. Twelve foot measurements were collected on 52 individuals (mean age 25.8 years) with the change in midfoot width used to place subjects in a pronated or normal foot mobility group. Dynamic plantar contact area was collected during walking with a pressure sensor platform. The 12 measures were entered into a stepwise regression analysis to determine the optimal set of measures associated with regional plantar surface area. A two variable model was found to describe the relationship between the foot measurements and forefoot plantar contact area (r(2)=0.79, p<0.0001). A four variable model was found to describe the relationship between the foot measurements and midfoot plantar contact area (r(2)=0.85, p<0.0001) in those individuals with a 1.26cm or greater change in midfoot width. The results indicate that clinicians can use a combination of simple, reliable and time efficient foot measures to explain 79% and 85% of the plantar surface area in the forefoot and midfoot, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of turbulence and surface growth models on the estimation of soot level in ethylene non-premixed flames

NASA Astrophysics Data System (ADS)

Yunardi, Y.; Munawar, Edi; Rinaldi, Wahyu; Razali, Asbar; Iskandar, Elwina; Fairweather, M.

2018-02-01

Soot prediction in a combustion system has become a subject of attention, as many factors influence its accuracy. An accurate temperature prediction will likely yield better soot predictions, since the inception, growth and destruction of the soot are affected by the temperature. This paper reported the study on the influences of turbulence closure and surface growth models on the prediction of soot levels in turbulent flames. The results demonstrated that a substantial distinction was observed in terms of temperature predictions derived using the k-ɛ and the Reynolds stress models, for the two ethylene flames studied here amongst the four types of surface growth rate model investigated, the assumption of the soot surface growth rate proportional to the particle number density, but independent on the surface area of soot particles, f ( A s ) = ρ N s , yields in closest agreement with the radial data. Without any adjustment to the constants in the surface growth term, other approaches where the surface growth directly proportional to the surface area and square root of surface area, f ( A s ) = A s and f ( A s ) = √ A s , result in an under- prediction of soot volume fraction. These results suggest that predictions of soot volume fraction are sensitive to the modelling of surface growth.

ANALYSIS OF ATMOSPHERE DEPOSITION SAMPLES FROM EASTON, PA

EPA Science Inventory

The report gives results of an analysis of samples of tenacious atmospheric deposits on exposed surfaces (e.g., automobiles and houses) in an industrial area near Easton, PA. The analysis was made at the request of the State of Pennsylvania. The Pennsylvania Department of Environ...

ANALYSIS OF ATMOSPHERE DEPOSITION SAMPLES FROM EASTON, PA

EPA Science Inventory

The report gives results of an analysis of samples of tenacious atmospheric deposits on exposed surfaces (e.g., automobiles and houses) in an industrial area near Easton, PA. he analysis was made at the request of the State of Pennsylvania. he Pennsylvania Department of Environme...

Serial Surgical Debridement of Common Pressure Injuries in the Nursing Home Setting: Outcomes and Findings.

PubMed

Anvar, Bardia; Okonkwo, Henry

2017-07-01

This study examined the efficacy of bedside surgical debridement in a nursing home population. A retrospective chart review was performed of sacrum, sacrococcyx, coccyx, ischium, and trochanter (SSCIT) region pressure injuries in the Skilled Wound Care practice (Los Angeles, CA). The patient population was refined from 2128 to 227 patients visited 8 or more times during nursing home stays found to have 1 or more SSCIT pressure injuries. Of the 227 patients, there were approximately 319 individual SSCIT wounds, with an average of 1.4 SSCIT wounds per patient. Bedside surgical debridement was performed using a sharp excisional technique on 190 of 319 (59.5%) SSCIT wounds. An analysis of the square surface area of the 190 debrided wound sites revealed a mean ulcer surface area of 20.76 cm2. Of those 190 wound sites, 138 (73%) had a reduction in square surface area, and 52 (27%) had no change or an increase in square surface area and were categorized as nonresponders. Of the wounds that did improve by a reduction in wound surface area, the average wound surface area reduction was 6.81 cm2 at 4 weeks (25%), 8.91 cm2 reduction at 8 weeks (33%), and 10.87 cm2 reduction at 12 weeks (40%). From the 190 wound sites, there were a total of 43 (23%) wounds that had a square surface area of 0 (reepithelialized), which has a healing rate of 23%. Traditional bedside debridement provides excellent results in reducing the square surface area for a majority of wounds. Whether used alone or as an adjunct to any treatment plan, the use of surgical sharp equipment aids in achieving good wound healing and advancing the rate of wound closure. Although wound healing requires many components, sharp debridement can effectively remove devitalized tissue and is a proven significant component to advancing wound closure.

High-precision surface analysis of the roughness of Michelangelo's David

NASA Astrophysics Data System (ADS)

Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Marras, Luciano; Materazzi, Marzia; Pampaloni, Enrico; Pezzati, Luca

2003-10-01

The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a statue, roughness measurement is a very useful contribution to document its surface conditions, to assess either changes due to restoration intervention or surface decays due to wearing agents, and to monitor its time-evolution in terms of shape variations. In this work we present the preliminary results of the statistical analysis carried out on acquired data relative to six areas of the Michelangelo"s David marble statue, representative of differently degraded surfaces. Determination of the roughness and its relative characteristic wavelength is shown.

Comparative Analysis of InSAR Digital Surface Models for Test Area Bucharest

NASA Astrophysics Data System (ADS)

Dana, Iulia; Poncos, Valentin; Teleaga, Delia

2010-03-01

This paper presents the results of the interferometric processing of ERS Tandem, ENVISAT and TerraSAR- X for digital surface model (DSM) generation. The selected test site is Bucharest (Romania), a built-up area characterized by the usual urban complex pattern: mixture of buildings with different height levels, paved roads, vegetation, and water bodies. First, the DSMs were generated following the standard interferometric processing chain. Then, the accuracy of the DSMs was analyzed against the SPOT HRS model (30 m resolution at the equator). A DSM derived by optical stereoscopic processing of SPOT 5 HRG data and also the SRTM (3 arc seconds resolution at the equator) DSM have been included in the comparative analysis.

Study of Surface Cleaning Methods and Pyrolysis Temperature on Nano-Structured Carbon Films using X-ray Photoelectron Spectroscopy

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

Kerber, Pranita B.; Porter, Lisa M.; McCullough, L. A.

2012-10-12

Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of di-block copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, (2009) 177]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of di-block copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) (PAN-b-PBA) at two different temperaturesmore » were carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included: HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % of nitrogen present in the films pyrolyzed at 600 °C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration reduced significantly for films pyrolyzed at 900 °C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen sub-peaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic cluster, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 °C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.« less

Study of surface cleaning methods and pyrolysis temperatures on nanostructured carbon films using x-ray photoelectron spectroscopy

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

Kerber, Pranita; Porter, Lisa M.; McCullough, Lynne A.

2012-11-15

Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of diblock copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, 177 (2009)]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of diblock copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) at two different temperatures weremore » carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % nitrogen was present in the films pyrolyzed at 600 Degree-Sign C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration decreased significantly for films pyrolyzed at 900 Degree-Sign C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen subpeaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic clusters, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 Degree-Sign C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.« less

[Evolution pattern of impervious surface in the Yuqiao Reservoir Watershed, Tianjin, China during the process of urbanization.

PubMed

Xie, Hui Jun; Li, Chong Wei; Zhang, Ya Juan; Song, Ai Yun

2016-04-22

Imperviousness in watershed is a key index to measure urbanization status which exerts an important impact on both eco-hydrological process and spatio-temporal pattern. Taking Yuqiao Reservoir Watershed as a case study area, based on the ENVI 5.1 software, the basic impervious surface information was extracted from remote sensing images taken in 1984, 1994, 2004 and 2013. The linear spectral mixture analysis (LSMA) model was applied to extract the impervious surface area (ISA) in nine coverage classes of watershed in order to analyze its spatio-temporal varying trend in terms of the landscape pattern metrics. Results showed that the RMSE and IS pixel accuracy of all samples were 0.005 and 85.4% respectively, which indicated that the method of extracting impervious surface on a basin scale was feasible. The average of ISA showed a linear growth, from 0.16 to 0.23, the impervious surface area increased by 4.9% in the whole watershed, and the total impervious surface area increased by 1 time. In the sub-basin road network, the impervious surface area increased gradually with the density of the road network, and its expansion pattern was of infilling growth. The patch shape of the middle coverage degree was irregular, and its fragmentation degree was the highest. The fragmentation degree and diversity of the landscape in the whole river basin increased year by year due to increasing human disturbance.

Vegetation Coverage and Impervious Surface Area Estimated Based on the Estarfm Model and Remote Sensing Monitoring

NASA Astrophysics Data System (ADS)

Hu, Rongming; Wang, Shu; Guo, Jiao; Guo, Liankun

2018-04-01

Impervious surface area and vegetation coverage are important biophysical indicators of urban surface features which can be derived from medium-resolution images. However, remote sensing data obtained by a single sensor are easily affected by many factors such as weather conditions, and the spatial and temporal resolution can not meet the needs for soil erosion estimation. Therefore, the integrated multi-source remote sensing data are needed to carry out high spatio-temporal resolution vegetation coverage estimation. Two spatial and temporal vegetation coverage data and impervious data were obtained from MODIS and Landsat 8 remote sensing images. Based on the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM), the vegetation coverage data of two scales were fused and the data of vegetation coverage fusion (ESTARFM FVC) and impervious layer with high spatiotemporal resolution (30 m, 8 day) were obtained. On this basis, the spatial variability of the seepage-free surface and the vegetation cover landscape in the study area was measured by means of statistics and spatial autocorrelation analysis. The results showed that: 1) ESTARFM FVC and impermeable surface have higher accuracy and can characterize the characteristics of the biophysical components covered by the earth's surface; 2) The average impervious surface proportion and the spatial configuration of each area are different, which are affected by natural conditions and urbanization. In the urban area of Xi'an, which has typical characteristics of spontaneous urbanization, landscapes are fragmented and have less spatial dependence.

Synthesis and catalytic activity of polysaccharide templated nanocrystalline sulfated zirconia

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

Sherly, K. B.; Rakesh, K.

Nanoscaled materials are of great interest due to their unique enhanced optical, electrical and magnetic properties. Sulfate-promoted zirconia has been shown to exhibit super acidic behavior and high activity for acid catalyzed reactions. Nanocrystalline zirconia was prepared in the presence of polysaccharide template by interaction between ZrOCl{sub 2}⋅8H{sub 2}O and chitosan template. The interaction was carried out in aqueous phase, followed by the removal of templates by calcination at optimum temperature and sulfation. The structural and textural features were characterized by powder XRD, TG, SEM and TEM. XRD patterns showed the peaks of the diffractogram were in agreement with themore » theoretical data of zirconia with the catalytically active tetragonal phase and average crystalline size of the particles was found to be 9 nm, which was confirmed by TEM. TPD using ammonia as probe, FTIR and BET surface area analysis were used for analyzing surface features like acidity and porosity. The BET surface area analysis showed the sample had moderately high surface area. FTIR was used to find the type species attached to the surface of zirconia. UV-DRS found the band gap of the zirconia was found to be 2.8 eV. The benzylation of o-xylene was carried out batchwise in atmospheric pressure and 433K temperature using sulfated zirconia as catalyst.« less

Assessment of Potential Location of High Arsenic Contamination Using Fuzzy Overlay and Spatial Anisotropy Approach in Iron Mine Surrounding Area

PubMed Central

Wirojanagud, Wanpen; Srisatit, Thares

2014-01-01

Fuzzy overlay approach on three raster maps including land slope, soil type, and distance to stream can be used to identify the most potential locations of high arsenic contamination in soils. Verification of high arsenic contamination was made by collection samples and analysis of arsenic content and interpolation surface by spatial anisotropic method. A total of 51 soil samples were collected at the potential contaminated location clarified by fuzzy overlay approach. At each location, soil samples were taken at the depth of 0.00-1.00 m from the surface ground level. Interpolation surface of the analysed arsenic content using spatial anisotropic would verify the potential arsenic contamination location obtained from fuzzy overlay outputs. Both outputs of the spatial surface anisotropic and the fuzzy overlay mapping were significantly spatially conformed. Three contaminated areas with arsenic concentrations of 7.19 ± 2.86, 6.60 ± 3.04, and 4.90 ± 2.67 mg/kg exceeded the arsenic content of 3.9 mg/kg, the maximum concentration level (MCL) for agricultural soils as designated by Office of National Environment Board of Thailand. It is concluded that fuzzy overlay mapping could be employed for identification of potential contamination area with the verification by surface anisotropic approach including intensive sampling and analysis of the substances of interest. PMID:25110751

Infrastructure stability surveillance with high resolution InSAR

NASA Astrophysics Data System (ADS)

Balz, Timo; Düring, Ralf

2017-02-01

The construction of new infrastructure in largely unknown and difficult environments, as it is necessary for the construction of the New Silk Road, can lead to a decreased stability along the construction site, leading to an increase in landslide risk and deformation caused by surface motion. This generally requires a thorough pre-analysis and consecutive surveillance of the deformation patterns to ensure the stability and safety of the infrastructure projects. Interferometric SAR (InSAR) and the derived techniques of multi-baseline InSAR are very powerful tools for a large area observation of surface deformation patterns. With InSAR and deriver techniques, the topographic height and the surface motion can be estimated for large areas, making it an ideal tool for supporting the planning, construction, and safety surveillance of new infrastructure elements in remote areas.

Multisensor analysis of hydrologic features with emphasis on the Seasat SAR

NASA Technical Reports Server (NTRS)

Foster, J. L.; Hall, D. K.

1981-01-01

Synthetic aperture radar (SAR) imagery of the Wind River Range area in Wyoming is compared with visible and near-infrared imagery of the same area. Data from the Seasat L-Band SAR and an aircraft X-Band SAR are compared with Landsat Return Beam Vidicon (RBV) visible data and near-infrared aerial photography and topographic maps of the same area. It is noted that visible and near-infrared data provide more information than the SAR data when conditions are the most favorable. The SAR penetrates clouds and snow, however, and data can be acquired day or night. Drainage density detail is good on SAR imagery because individual streams show up well owing to riparian vegetation; this causes higher radar reflections which result from the 'rough' surface which vegetation creates. In the winter image, the X-Band radar data show high returns because of cracks on the lake ice surfaces. High returns can also be seen in the L-Band SAR imagery of the lakes due to ripples on the surface induced by wind. It is concluded that the use of multispectral data would optimize analysis of hydrologic features.

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.

Effect of Ionic Soil Stabilizers on Soil-Water Characteristic of Special Clay

NASA Astrophysics Data System (ADS)

Cui, D.; Xiang, W.

2011-12-01

The engineering properties of special clay are conventionally improved through the use of chemical additive such as ionic soil stabilizer (ISS). Such special clays are often referred to as stabilized or treated clays. The soil-water characteristic curves (SWCC) of special clays from Henan province and Hubei province were measured both in natural and stabilized conditions using the pressure plate apparatus in the suction range of 0-500 kPa. The SWCC results are used to interpret the special clays behavior due to stabilizer treatment. In addition, relationships were developed between the basic clay and stabilized properties such as specific surface area and pore size distribution. The analysis showed that specific surface area decreases, cumulative pore volume and average pore size diameter decrease, dehydration rate slows and the thickness of water film thins after treatment with Ionic Soil Stabilizer. The research data and interpretation analysis presented here can be extended to understand the water film change behaviors influencing the mechanical and physical properties of stabilized special clay soils. KEY WORDS: ionic soil stabilizer, special clay, pore size diameter, specific surface area, soil water characteristic curve, water film

Comparing digital data processing techniques for surface mine and reclamation monitoring

NASA Technical Reports Server (NTRS)

Witt, R. G.; Bly, B. G.; Campbell, W. J.; Bloemer, H. H. L.; Brumfield, J. O.

1982-01-01

The results of three techniques used for processing Landsat digital data are compared for their utility in delineating areas of surface mining and subsequent reclamation. An unsupervised clustering algorithm (ISOCLS), a maximum-likelihood classifier (CLASFY), and a hybrid approach utilizing canonical analysis (ISOCLS/KLTRANS/ISOCLS) were compared by means of a detailed accuracy assessment with aerial photography at NASA's Goddard Space Flight Center. Results show that the hybrid approach was superior to the traditional techniques in distinguishing strip mined and reclaimed areas.

Analysis of the geomorphology surrounding the Chang'e-3 landing site

NASA Astrophysics Data System (ADS)

Li, Chun-Lai; Mu, Ling-Li; Zou, Xiao-Duan; Liu, Jian-Jun; Ren, Xin; Zeng, Xing-Guo; Yang, Yi-Man; Zhang, Zhou-Bin; Liu, Yu-Xuan; Zuo, Wei; Li, Han

2014-12-01

Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surface environment. To better understand the environment of this region, this paper utilizes the available high-resolution topography data, image data and geological data to carry out a detailed analysis and research on the area surrounding the landing site (Sinus Iridum and 45 km×70 km of the landing area) as well as on the topography, landform, geology and lunar dust of the area surrounding the landing site. A general topographic analysis of the surrounding area is based on a digital elevation model and digital elevation model data acquired by Chang'e-2 that have high resolution; the geology analysis is based on lunar geological data published by USGS; the study on topographic factors and distribution of craters and rocks in the surrounding area covering 4 km×4 km or even smaller is based on images from the CE-3 landing camera and images from the topographic camera; an analysis is done of the effect of the CE-3 engine plume on the lunar surface by comparing images before and after the landing using data from the landing camera. A comprehensive analysis of the results shows that the landing site and its surrounding area are identified as typical lunar mare with flat topography. They are suitable for maneuvers by the rover, and are rich in geological phenomena and scientific targets, making it an ideal site for exploration.

Preliminary determination of geothermal working area based on Thermal Infrared and Synthetic Aperture Radar (SAR) remote sensing

NASA Astrophysics Data System (ADS)

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

2017-12-01

Remote sensing is one of the methods for geothermal exploration. This method can be used to map the geological structures, manifestations, and predict the geothermal potential area. The results from remote sensing were used as guidance for the next step exploration. Analysis of target in remote sensing is an efficient method to delineate geothermal surface manifestation without direct contact to the object. The study took a place in District Merangin, Jambi Province, Indonesia. The area was selected due to existing of Merangin volcanic complex composed by Mounts Sumbing and Hulunilo with surface geothermal manifestations presented by hot springs and hot pools. The location of surface manifestations could be related with local and regional structures of Great Sumatra Fault. The methods used in this study were included identification of volcanic products, lineament extraction, and lineament density quantification. The objective of this study is to delineate the potential zones for sitting the geothermal working site based on Thermal Infrared and Synthetic Aperture Radar (SAR) sensors. The lineament-related to geological structures, was aimed for high lineament density, is using ALOS - PALSAR (Advanced Land Observing Satellite - The Phased Array type L-band Synthetic Aperture Radar) level 1.1. The Normalized Difference Vegetation Index (NDVI) analysis was used to predict the vegetation condition using Landsat 8 OLI-TIRS (The Operational Land Imager - Thermal Infrared Sensor). The brightness temperature was extracted from TIR band to estimate the surface temperature. Geothermal working area identified based on index overlay method from extracted parameter of remote sensing data was located at the western part of study area (Graho Nyabu area). This location was identified because of the existence of high surface temperature about 30°C, high lineament density about 4 - 4.5 km/km2 and low NDVI values less than 0.3.

Implications of contamination and surface area ratios for Langmuir probe diagnostics on CubeSats

NASA Astrophysics Data System (ADS)

Suresh, P.; Swenson, C.

2009-12-01

Theories describing the current collected by a biased probe under various conditions are necessary for such observation to be used to accurately determine plasma properties. Langmuir probes are routinely used on spacecraft to measure plasma parameters such as density, temperature, and vehicle charging. The collected current is a function of the potential between the surrounding plasma and probe surface. There have been both observations of and concepts for unaccounted variations of this potential which limit the application of Langmuir probe theory for determining plasma properties. These variations occur due to spatial variations of the work function across the probe surface due to non-uniformity of the crystalline surface properties and surface contamination of the probe. Currently we do not have theoretical expressions which consider these factors as first principles in their derivation. In the event of these surface potential variations, the analysis of the plasma using the currently available theories of the Langmuir probe yield erroneous results. We present a theory which models the current as a function of the surface potential variations. Another consideration for Langmuir probes on CubeSats is the ratio of the probe area to the return current collection area. If the area ratio is unfavorable this can also lead to erroneous results in the interpretation of observations. A mathematical formulation of the current collected by the probe for contaminated surfaces is presented and compared with data from a Langmuir probe flown on a sounding rocket mission. The implications of using Langmuir probes on CubeSats given the engineering limitations of probe cleanliness and area ratios are reviewed.

Degradation of surfactant-associated protein B (SP-B) during in vitro conversion of large to small surfactant aggregates.

PubMed Central

Veldhuizen, R A; Inchley, K; Hearn, S A; Lewis, J F; Possmayer, F

1993-01-01

Pulmonary surfactant obtained from lung lavages can be separated by differential centrifugation into two distinct subfractions known as large surfactant aggregates and small surfactant aggregates. The large-aggregate fraction is the precursor of the small-aggregate fraction. The ratio of the small non-surface-active to large surface-active surfactant aggregates increases after birth and in several types of lung injury. We have utilized an in vitro system, surface area cycling, to study the conversion of large into small aggregates. Small aggregates generated by surface area cycling were separated from large aggregates by centrifugation at 40,000 g for 15 min rather than by the normal sucrose gradient centrifugation. This new separation method was validated by morphological studies. Surface-tension-reducing activity of total surfactant extracts, as measured with a pulsating-bubble surfactometer, was impaired after surface area cycling. This impairment was related to the generation of small aggregates. Immunoblot analysis of large and small aggregates separated by sucrose gradient centrifugation revealed the presence of detectable amounts of surfactant-associated protein B (SP-B) in large aggregates but not in small aggregates. SP-A was detectable in both large and small aggregates. PAGE of cycled and non-cycled surfactant showed a reduction in SP-B after surface area cycling. We conclude that SP-B is degraded during the formation of small aggregates in vitro and that a change in surface area appears to be necessary for exposing SP-B to protease activity. Images Figure 2 Figure 5 Figure 6 Figure 7 PMID:8216208

Analysis of Thematic Mapper data for studying the suspended matter distribution in the coastal area of the German Bight (North Sea)

NASA Technical Reports Server (NTRS)

Doerffer, R.; Fischer, J.; Stoessel, M.; Brockmann, C.; Grassl, H.

1989-01-01

Thematic Mapper data were analyzed with respect to its capability for mapping the complex structure and dynamics of suspended matter distribution in the coastal area of the German Bight (North Sea). Three independent pieces of information were found by factor analysis of all seven TM channels: suspended matter concentration, atmospheric scattering, and sea surface temperature. For the required atmospheric correction, the signal-to-noise ratios of Channels 5 and 7 have to be improved by averaging over 25 x 25 pixels, which also makes it possible to monitor the aerosol optical depth and aerosol type over cloud-free water surfaces. Near-surface suspended matter concentrations may be detected with an accuracy of factor less than 2 by using an algorithm derived from radiative transfer model calculation. The patchiness of suspended matter and its relation to underwater topography was analyzed with autocorrelation and cross-correlation.

A Probabilistic Analysis of Surface Water Flood Risk in London.

PubMed

Jenkins, Katie; Hall, Jim; Glenis, Vassilis; Kilsby, Chris

2018-06-01

Flooding in urban areas during heavy rainfall, often characterized by short duration and high-intensity events, is known as "surface water flooding." Analyzing surface water flood risk is complex as it requires understanding of biophysical and human factors, such as the localized scale and nature of heavy precipitation events, characteristics of the urban area affected (including detailed topography and drainage networks), and the spatial distribution of economic and social vulnerability. Climate change is recognized as having the potential to enhance the intensity and frequency of heavy rainfall events. This study develops a methodology to link high spatial resolution probabilistic projections of hourly precipitation with detailed surface water flood depth maps and characterization of urban vulnerability to estimate surface water flood risk. It incorporates probabilistic information on the range of uncertainties in future precipitation in a changing climate. The method is applied to a case study of Greater London and highlights that both the frequency and spatial extent of surface water flood events are set to increase under future climate change. The expected annual damage from surface water flooding is estimated to be to be £171 million, £343 million, and £390 million/year under the baseline, 2030 high, and 2050 high climate change scenarios, respectively. © 2017 Society for Risk Analysis.

Correlations between brain structure and symptom dimensions of psychosis in schizophrenia, schizoaffective, and psychotic bipolar I disorders.

PubMed

Padmanabhan, Jaya L; Tandon, Neeraj; Haller, Chiara S; Mathew, Ian T; Eack, Shaun M; Clementz, Brett A; Pearlson, Godfrey D; Sweeney, John A; Tamminga, Carol A; Keshavan, Matcheri S

2015-01-01

Structural alterations may correlate with symptom severity in psychotic disorders, but the existing literature on this issue is heterogeneous. In addition, it is not known how cortical thickness and cortical surface area correlate with symptom dimensions of psychosis. Subjects included 455 individuals with schizophrenia, schizoaffective, or bipolar I disorders. Data were obtained as part of the Bipolar Schizophrenia Network for Intermediate Phenotypes study. Diagnosis was made through the Structured Clinical Interview for DSM-IV. Positive and negative symptom subscales were assessed using the Positive and Negative Syndrome Scale. Structural brain measurements were extracted from T1-weight structural MRIs using FreeSurfer v5.1 and were correlated with symptom subscales using partial correlations. Exploratory factor analysis was also used to identify factors among those regions correlating with symptom subscales. The positive symptom subscale correlated inversely with gray matter volume (GMV) and cortical thickness in frontal and temporal regions, whereas the negative symptom subscale correlated inversely with right frontal cortical surface area. Among regions correlating with the positive subscale, factor analysis identified four factors, including a temporal cortical thickness factor and frontal GMV factor. Among regions correlating with the negative subscale, factor analysis identified a frontal GMV-cortical surface area factor. There was no significant diagnosis by structure interactions with symptom severity. Structural measures correlate with positive and negative symptom severity in psychotic disorders. Cortical thickness demonstrated more associations with psychopathology than cortical surface area. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Surface-emitting circular DFB, disk- and ring- Bragg resonator lasers with chirped gratings: a unified theory and comparative study.

PubMed

Sun, Xiankai; Yariv, Amnon

2008-06-09

We have developed a theory that unifies the analysis of the modal properties of surface-emitting chirped circular grating lasers. This theory is based on solving the resonance conditions which involve two types of reflectivities of chirped circular gratings. This approach is shown to be in agreement with previous derivations which use the characteristic equations. Utilizing this unified analysis, we obtain the modal properties of circular DFB, disk-, and ring- Bragg resonator lasers. We also compare the threshold gain, single mode range, quality factor, emission efficiency, and modal area of these types of circular grating lasers. It is demonstrated that, under similar conditions, disk Bragg resonator lasers have the highest quality factor, the highest emission efficiency, and the smallest modal area, indicating their suitability in low-threshold, high-efficiency, ultracompact laser design, while ring Bragg resonator lasers have a large single mode range, high emission efficiency, and large modal area, indicating their suitability for high-efficiency, large-area, high-power applications.

Thermal Band Analysis of Agricultural Land Use and its Effects on Bioclimatic Comfort: The Case of Pasinler

NASA Astrophysics Data System (ADS)

Avdan, Uǧur; Demircioglu Yildiz, Nalan; Dagliyar, Ayse; Yigit Avdan, Zehra; Yilmaz, Sevgi

2014-05-01

Resolving the problems that arise due to the land use are not suitable for the purpose in the rural and urban areas most suitable for land use of parameters to be determined. Unintended and unplanned developments in the use of agricultural land in our country caused increases the losses by soil erosion. In this study, Thermal Band analysis is made in Pasinler city center with the aim of identifying bioclimatic comfort values of the different agricultural area. Satellite images can be applied for assessing the thermal urban environment as well as for defining heat islands in agricultural areas. In this context, temperature map is tried to be produced with land surface temperature (LST) analysis made on Landsat TM5 satellite image. The Landsat 5 images was obtained from USGS for the study area. Using Landsat bands of the study area was mapped by supervised classification with the maximum likelihood classification algorithm of ERDAS imagine 2011 software. Normalized Difference Vegetation Index (NDVI) image was produced by using Landsat images. The digital number of the Landsat thermal infrared band (10.40 - 12.50 µm) is converted to the spectral radiance. The surface emissivity was calculated by using NDVI. The spatial pattern of land surface temperature in the study area is taken to characterize their local effects on agricultural land. Areas having bioclimatic comfort and ecologically urbanized, are interpreted with different graphical presentation technics. The obtained results are important because they create data bases for sustainable urban planning and provide a direction for planners and governors. As a result of rapid changes in land use, rural ecosystems and quality of life are deteriorated and decreased. In the presence of increased building density, for the comfortable living of people natural and cultural resources should be analyzed in detail. For that reason, optimal land use planning should be made in rural area.

Mud Flow Characteristics Occurred in Izuoshima Island, 2013

NASA Astrophysics Data System (ADS)

Takebayashi, H.; Egashira, S.; Fujita, M.

2015-12-01

Landslides and mud flows were occurred in the west part of the Izuoshima Island, Japan on 16 October 2013. The Izuoshima Island is a volcanic island and the land surface is covered by the volcanic ash sediment in 1m depth. Hence, the mud flow with high sediment concentration was formed. The laminar layer is formed in the debris flow from the bed to the fluid surface. On the other hand, the laminar flow is restricted near the bed in the mud flow and the turbulence flow is formed on the laminar flow layer. As a result, the equilibrium slope of the mud flow becomes smaller comparing to the debris flow. In this study, the numerical analysis mud flow model considering the effect of turbulence flow on the equilibrium slope of the mud flow is developed. Subsequently, the model is applied to the mud flow occurred in the Izuoshima Island and discussed the applicability of the model and the flow characteristics of the mud flow. The differences of the horizontal flow areas between the simulated results and the field data are compared and it was found that the outline of the horizontal shape of the flow areas is reproduced well. Furthermore, the horizontal distribution of the erosion and deposition area is reproduced by the numerical analysis well except for the residential area (Kandachi area). Kandachi area is judged as the erosion area by the field observation, but the sediment was deposited in the numerical analysis. It is considered that the 1.5hour heavy rain over 100mm/h after the mud flow makes the discrepancy. The difference of the horizontal distribution of the maximum flow surface elevation between the simulated results and the field data are compared and it was found that the simulated flow depth is overestimated slightly, because of the wider erosion area due to the coarse resolution elevation data. The averaged velocity and the depth of the mud flow was enough large to collapse the houses.

InterProSurf: a web server for predicting interacting sites on protein surfaces

PubMed Central

Negi, Surendra S.; Schein, Catherine H.; Oezguen, Numan; Power, Trevor D.; Braun, Werner

2009-01-01

Summary A new web server, InterProSurf, predicts interacting amino acid residues in proteins that are most likely to interact with other proteins, given the 3D structures of subunits of a protein complex. The prediction method is based on solvent accessible surface area of residues in the isolated subunits, a propensity scale for interface residues and a clustering algorithm to identify surface regions with residues of high interface propensities. Here we illustrate the application of InterProSurf to determine which areas of Bacillus anthracis toxins and measles virus hemagglutinin protein interact with their respective cell surface receptors. The computationally predicted regions overlap with those regions previously identified as interface regions by sequence analysis and mutagenesis experiments. PMID:17933856

Using the conservative nature of fresh leaf surface density to measure foliar area

NASA Astrophysics Data System (ADS)

Castillo, Omar S.; Zaragoza, Esther M.; Alvarado, Carlos J.; Barrera, Maria G.; Dasgupta-Schubert, Nabanita

2014-10-01

For a herbaceous species, the inverse of the fresh leaf surface density, the Hughes constant, is nearly conserved. We apply the Hughes constant to develop an absolute method of leafarea measurement that requires no regression fits, prior calibrations or oven-drying. The Hughes constant was determined in situ using a known geometry and weights of a sub-set obtained from the fresh leaves whose areas are desired. Subsequently, the leaf-areas (at any desired stratification level), were derived by utilizing the Hughes constant and the masses of the fresh leaves. The proof of concept was established for leaf-discs of the plants Mandevilla splendens and Spathiphyllum wallisii. The conservativeness of the Hughes constant over individual leaf-zones and different leaftypes from the leaves of each species was quantitatively validated. Using the globally averaged Hughes constant for each species, the leaf-area of these and additional co-species plants, were obtained. The leaf-area-measurement-by-mass was cross-checked with standard digital image analysis. There were no statistically significant differences between the leaf-area-measurement-by-mass and the digital image analysis measured leaf-areas and the linear correlation between the two methods was very good. Leaf-areameasurement- by-mass was found to be rapid and simple with accuracies comparable to the digital image analysis method. The greatly reduced cost of leaf-area-measurement-by-mass could be beneficial for small agri-businesses in developing countries.

The use of fractography to supplement analysis of bone mechanical properties in different strains of mice.

PubMed

Wise, L M; Wang, Z; Grynpas, M D

2007-10-01

Fractography has not been fully developed as a useful technique in assessing failure mechanisms of bone. While fracture surfaces of osteonal bone have been explored, this may not apply to conventional mechanical testing of mouse bone. Thus, the focus of this work was to develop and evaluate the efficacy of a fractography protocol for use in supplementing the interpretation of failure mechanisms in mouse bone. Micro-computed tomography and three-point bending were performed on femora of two groups of 6-month-old mice (C57BL/6 and a mixed strain background of 129SV/C57BL6). SEM images of fracture surfaces were collected, and areas of "tension", "compression" and "transition" were identified. Percent areas of roughness were identified and estimated within areas of "tension" and "compression" and subsequently compared to surface roughness measurements generated from an optical profiler. Porosity parameters were determined on the tensile side. Linear regression analysis was performed to evaluate correlations between certain parameters. Results show that 129 mice exhibit significantly increased bone mineral density (BMD), number of "large" pores, failure strength, elastic modulus and energy to failure compared to B6 mice (p<0.001). Both 129 and B6 mice exhibit significantly (p<0.01) more percent areas of tension (49+/-1%, 42+/-2%; respectively) compared to compression (26+/-2%, 31+/-1%; respectively). In terms of "roughness", B6 mice exhibit significantly less "rough" areas (30+/-4%) compared to "smooth" areas (70+/-4%) on the tensile side only (p<0.001). Qualitatively, 129 mice demonstrate more evidence of bone toughening through fiber bridging and loosely connected fiber bundles. The number of large pores is positively correlated with failure strength (p=0.004), elastic modulus (p=0.002) and energy to failure (p=0.041). Percent area of tensile surfaces is positively correlated with failure strength (p<0.001), elastic modulus (p=0.016) and BMD (p=0.037). Percent area of rough compressive surfaces is positively correlated with energy to failure (p=0.039). Evaluation of fracture surfaces has helped to explain why 129 mice have increased mechanical properties compared to B6 mice, namely via toughening mechanisms on the compressive side of failure. Several correlations exist between fractography parameters and mechanical behavior, supporting the utility of fractography with skeletal mouse models.

Ablation article and method

NASA Technical Reports Server (NTRS)

Erickson, W. D.; Sullivan, E. M. (Inventor)

1973-01-01

An ablation article, such as a conical heat shield, having an ablating surface is provided with at least one discrete area of at least one seed material, such as aluminum. When subjected to ablation conditions, the seed material is ablated. Radiation emanating from the ablated seed material is detected to analyze ablation effects without disturbing the ablation surface. By providing different seed materials having different radiation characteristics, the ablating effects on various areas of the ablating surface can be analyzed under any prevailing ablation conditions. The ablating article can be provided with means for detecting the radiation characteristics of the ablated seed material to provide a self-contained analysis unit.

Estimating the relationship between urban 3D morphology and land surface temperature using airborne LiDAR and Landsat-8 Thermal Infrared Sensor data

NASA Astrophysics Data System (ADS)

Lee, J. H.

2015-12-01

Urban forests are known for mitigating the urban heat island effect and heat-related health issues by reducing air and surface temperature. Beyond the amount of the canopy area, however, little is known what kind of spatial patterns and structures of urban forests best contributes to reducing temperatures and mitigating the urban heat effects. Previous studies attempted to find the relationship between the land surface temperature and various indicators of vegetation abundance using remote sensed data but the majority of those studies relied on two dimensional area based metrics, such as tree canopy cover, impervious surface area, and Normalized Differential Vegetation Index, etc. This study investigates the relationship between the three-dimensional spatial structure of urban forests and urban surface temperature focusing on vertical variance. We use a Landsat-8 Thermal Infrared Sensor image (acquired on July 24, 2014) to estimate the land surface temperature of the City of Sacramento, CA. We extract the height and volume of urban features (both vegetation and non-vegetation) using airborne LiDAR (Light Detection and Ranging) and high spatial resolution aerial imagery. Using regression analysis, we apply empirical approach to find the relationship between the land surface temperature and different sets of variables, which describe spatial patterns and structures of various urban features including trees. Our analysis demonstrates that incorporating vertical variance parameters improve the accuracy of the model. The results of the study suggest urban tree planting is an effective and viable solution to mitigate urban heat by increasing the variance of urban surface as well as evaporative cooling effect.

Reliability and statistical power analysis of cortical and subcortical FreeSurfer metrics in a large sample of healthy elderly.

PubMed

Liem, Franziskus; Mérillat, Susan; Bezzola, Ladina; Hirsiger, Sarah; Philipp, Michel; Madhyastha, Tara; Jäncke, Lutz

2015-03-01

FreeSurfer is a tool to quantify cortical and subcortical brain anatomy automatically and noninvasively. Previous studies have reported reliability and statistical power analyses in relatively small samples or only selected one aspect of brain anatomy. Here, we investigated reliability and statistical power of cortical thickness, surface area, volume, and the volume of subcortical structures in a large sample (N=189) of healthy elderly subjects (64+ years). Reliability (intraclass correlation coefficient) of cortical and subcortical parameters is generally high (cortical: ICCs>0.87, subcortical: ICCs>0.95). Surface-based smoothing increases reliability of cortical thickness maps, while it decreases reliability of cortical surface area and volume. Nevertheless, statistical power of all measures benefits from smoothing. When aiming to detect a 10% difference between groups, the number of subjects required to test effects with sufficient power over the entire cortex varies between cortical measures (cortical thickness: N=39, surface area: N=21, volume: N=81; 10mm smoothing, power=0.8, α=0.05). For subcortical regions this number is between 16 and 76 subjects, depending on the region. We also demonstrate the advantage of within-subject designs over between-subject designs. Furthermore, we publicly provide a tool that allows researchers to perform a priori power analysis and sensitivity analysis to help evaluate previously published studies and to design future studies with sufficient statistical power. Copyright © 2014 Elsevier Inc. All rights reserved.

Micromorphological characterization of zinc/silver particle composite coatings.

PubMed

Méndez, Alia; Reyes, Yolanda; Trejo, Gabriel; StĘpień, Krzysztof; Ţălu, Ştefan

2015-12-01

The aim of this study was to evaluate the three-dimensional (3D) surface micromorphology of zinc/silver particles (Zn/AgPs) composite coatings with antibacterial activity prepared using an electrodeposition technique. These 3D nanostructures were investigated over square areas of 5 μm × 5 μm by atomic force microscopy (AFM), fractal, and wavelet analysis. The fractal analysis of 3D surface roughness revealed that (Zn/AgPs) composite coatings have fractal geometry. Triangulation method, based on the linear interpolation type, applied for AFM data was employed in order to characterise the surfaces topographically (in amplitude, spatial distribution and pattern of surface characteristics). The surface fractal dimension Df , as well as height values distribution have been determined for the 3D nanostructure surfaces. © 2015 The Authors published by Wiley Periodicals, Inc.

Geology and surface geochemistry of the Roosevelt Springs Known Geothermal Resource Area, Utah

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

Lovell, J.S.; Meyer, W.T.; Atkinson, D.J.

1980-01-01

Available data on the Roosevelt area were synthesized to determine the spatial arrangement of the rocks, and the patterns of mass and energy flow within them. The resulting model lead to a new interpretation of the geothermal system, and provided ground truth for evaluating the application of soil geochemistry to exploration for concealed geothermal fields. Preliminary geochemical studies comparing the surface microlayer to conventional soil sampling methods indicated both practical and chemical advantages for the surface microlayer technique, which was particularly evident in the case of As, Sb and Cs. Subsequent multi-element analyses of surface microlayer samples collected over anmore » area of 100 square miles were processed to produce single element contour maps for 41 chemical parameters. Computer manipulation of the multi-element data using R-mode factor analysis provided the optimum method of interpretation of the surface microlayer data. A trace element association of As, Sb and Cs in the surface microlayer provided the best indication of the leakage of geothermal solutions to the surface, while regional mercury trends may reflect the presence of a mercury vapour anomaly above a concealed heat source.« less

Analysis of The Surface Radiative Budget Using ATLAS Data for San Juan, Puerto Rico

NASA Technical Reports Server (NTRS)

Luvall, Jeffrey C.; Rickman, D. L.; Gonzalez, J.; Comarazamy, Daniel; Picon, Ana

2007-01-01

The additional beating of the air over the city is the result of the replacement of naturally vegetated surfaces with those composed of asphalt, concrete, rooftops and other man-made materials. The temperatures of these artificial surfaces can be 20 to 40 C higher than vegetated surfaces. This produces a dome of elevated air temperatures 5 to 8 C greater over the city, compared to the air temperatures over adjacent rural areas. Urban landscapes are a complex mixture of vegetated and nonvegetated surfaces. It is difficult to take enough temperature measurements over a large city area to characterize the complexity of urban radiant surface temperature variability. The NASA Airborne Thermal and Land Applications Sensor (ATLAS) operates in the visual and IR bands was used in February 2004 to collect data from San Juan, Puerto Rico with the main objective of investigating the Urban Heat Island (UHI) in tropical cities.

APPLICATIONS OF SURFACE ANALYSIS IN THE ENVIRONMENTAL SCIENCES: DEHALOGENATION OF CHLOROCARBONS WITH ZERO-VALENT IRON AND IRON-CONTAINING MINERAL SURFACES. (R828164)

EPA Science Inventory

Halogenated organic compounds are common pollutants in groundwater. Consequently, there is widespread interest in understanding the reactions of these compounds in the environment and developing remediation strategies. One area of ongoing research involves the reductive dechlo...

An interdisciplinary analysis of ERTS data for Colorado mountain environments using ADP Techniques

NASA Technical Reports Server (NTRS)

Hoffer, R. M. (Principal Investigator)

1972-01-01

Author identified significant preliminary results from the Ouachita portion of the Texoma frame of data indicate many potentials in the analysis and interpretation of ERTS data. It is believed that one of the more significant aspects of this analysis sequence has been the investigation of a technique to relate ERTS analysis and surface observation analysis. At present a sequence involving (1) preliminary analysis based solely upon the spectral characteristics of the data, followed by (2) a surface observation mission to obtain visual information and oblique photography to particular points of interest in the test site area, appears to provide an extremely efficient technique for obtaining particularly meaningful surface observation data. Following such a procedure permits concentration on particular points of interest in the entire ERTS frame and thereby makes the surface observation data obtained to be particularly significant and meaningful. The analysis of the Texoma frame has also been significant from the standpoint of demonstrating a fast turn around analysis capability. Additionally, the analysis has shown the potential accuracy and degree of complexity of features that can be identified and mapped using ERTS data.

[Phytoremediation of Petroleum Contaminated Soils with Iris pseudacorus L. and the Metabolic Analysis in Roots].

PubMed

Wang, Ya-nan; Cheng, Li-juan; Zhou, Qi-xing

2016-04-15

In this study, we performed a greenhouse pot-culture experiment to investigate the potential of a wild ornamental plant Iris pseudacorus L. in remediating petroleum contaminated soils from the Dagang Oilfield in Tianjin, China. The results suggested that Iris pseudacorus L. had great resistance to ≤ 40,000 mg · kg(⁻¹ of total petroleum hydrocarbons (TPHs). The removal rate of TPHs with concentrations of 10,000 mg · kg⁻¹, 20,000 mg · kg⁻¹ and 40,000 mg · kg⁻¹ in soils by Iris pseudacorus L. was 42.1%, 33.1% 31.2%, respectively, much higher than those in the corresponding controls (31.8%, 21.3% 11.9%, respectively) (P < 0.05). The root specific surface area of Iris pseudacorus L. was determined by the root scanner. The results suggested that TPHs with concentrations of 10,000 mg · kg⁻¹, 20,000 mg · kg⁻¹ and 40,000 mg · kg⁻¹ in soils increased the root specific surface area comparing with the controls. Additionally, the metabolic analysis showed that root metabolism changed to different degrees under the stress of TPHs, and the levels or species of metabolites had a significant change (P < 0.001). Furthermore, the results showed that 5 of 11 metabolites (VIP value > 1.2) with the root specific surface area from the PLS-DA model analysis, including ethanedioic acid, lactic acid, 2-butenedioic acid, phosphate and propanedioic acid, were positively correlated with the root specific surface area, but the others, gluconic acid, uridine, butanoic acid, maltose, 9,12-octadecadienoic acid, phenylalanine, were negatively correlated with it. In conclusion, using Iris pseudacorus L. to remediate petroleum contaminated soils is feasible, and the metabolic analysis in roots is useful to better understand the metabolic response of plants exposure to petroleum contaminated soils, and then reveals its remediated mechanisms.

In situ atomic force microscopy analysis of morphology and particle size changes in lithium iron phosphate cathode during discharge.

PubMed

Demirocak, Dervis Emre; Bhushan, Bharat

2014-06-01

Li-ion batteries offer great promise for future plug-in hybrid electric vehicles (PHEVs) and pure electric vehicles (EVs). One of the challenges is to improve the cycle life of Li-ion batteries which requires detailed understanding of the aging phenomenon. In situ techniques are especially valuable to understand aging since it allows monitoring the physical and chemical changes in real time. In this study, in situ atomic force microscopy (AFM) is utilized to study the changes in morphology and particle size of LiFePO4 cathode during discharge. The guidelines for in situ AFM cell design for accurate and reliable measurements based on different designs are presented. The effect of working electrode to counter electrode surface area ratio on cycling data of an in situ cell is also discussed. Analysis of the surface area change in LiFePO4 particles when the cell was cycled between 100% and 70% state of charge is presented. Among four particles analyzed, surface area increase of particles during Li intercalation of LiFePO4 spanned from 1.8% to 14.3% indicating the inhomogeneous nature of the cathode surface. Copyright © 2014 Elsevier Inc. All rights reserved.

Periodic minimal surfaces

NASA Astrophysics Data System (ADS)

Mackay, Alan L.

1985-04-01

A minimal surface is one for which, like a soap film with the same pressure on each side, the mean curvature is zero and, thus, is one where the two principal curvatures are equal and opposite at every point. For every closed circuit in the surface, the area is a minimum. Schwarz1 and Neovius2 showed that elements of such surfaces could be put together to give surfaces periodic in three dimensions. These periodic minimal surfaces are geometrical invariants, as are the regular polyhedra, but the former are curved. Minimal surfaces are appropriate for the description of various structures where internal surfaces are prominent and seek to adopt a minimum area or a zero mean curvature subject to their topology; thus they merit more complete numerical characterization. There seem to be at least 18 such surfaces3, with various symmetries and topologies, related to the crystallographic space groups. Recently, glyceryl mono-oleate (GMO) was shown by Longley and McIntosh4 to take the shape of the F-surface. The structure postulated is shown here to be in good agreement with an analysis of the fundamental geometry of periodic minimal surfaces.

Hypogeal geological survey in the "Grotta del Re Tiberio" natural cave (Apennines, Italy): a valid tool for reconstructing the structural setting

NASA Astrophysics Data System (ADS)

Ghiselli, Alice; Merazzi, Marzio; Strini, Andrea; Margutti, Roberto; Mercuriali, Michele

2011-06-01

As karst systems are natural windows to the underground, speleology, combined with geological surveys, can be useful tools for helping understand the geological evolution of karst areas. In order to enhance the reconstruction of the structural setting in a gypsum karst area (Vena del Gesso, Romagna Apennines), a detailed analysis has been carried out on hypogeal data. Structural features (faults, fractures, tectonic foliations, bedding) have been mapped in the "Grotta del Re Tiberio" cave, in the nearby gypsum quarry tunnels and open pit benches. Five fracture systems and six fault systems have been identified. The fault systems have been further analyzed through stereographic projections and geometric-kinematic evaluations in order to reconstruct the relative chronology of these structures. This analysis led to the detection of two deformation phases. The results permitted linking of the hypogeal data with the surface data both at a local and regional scale. At the local scale, fracture data collected in the underground have been compared with previous authors' surface data coming from the quarry area. The two data sets show a very good correspondence, as every underground fracture system matches with one of the surface fracture system. Moreover, in the cave, a larger number of fractures belonging to each system could be mapped. At the regional scale, the two deformation phases detected can be integrated in the structural setting of the study area, thereby enhancing the tectonic interpretation of the area ( e.g., structures belonging to a new deformation phase, not reported before, have been identified underground). The structural detailed hypogeal survey has, thus, provided very useful data, both by integrating the existing information and revealing new data not detected at the surface. In particular, some small structures ( e.g., displacement markers and short fractures) are better preserved in the hypogeal environment than on the surface where the outcropping gypsum is more exposed to dissolution and recrystallization. The hypogeal geological survey, therefore, can be considered a powerful tool for integrating the surface and log data in order to enhance the reconstruction of the deformational history and to get a three-dimensional model of the bedrock in karst areas.

City landscape changes effects on land surface temperature in Bucharest metropolitan area

NASA Astrophysics Data System (ADS)

Savastru, Dan M.; Zoran, Maria A.; Savastru, Roxana S.; Dida, Adrian I.

2017-10-01

This study investigated the influences of city land cover changes and extreme climate events on land surface temperature in relationship with several biophysical variables in Bucharest metropolitan area of Romania through satellite and in-situ monitoring data. Remote sensing data from IKONOS, Landsat TM/ETM+ and time series MODIS Terra/Aqua and NOAA AVHRR sensors have been used to assess urban land cover- temperature interactions over 2000 - 2016 period. Time series Thermal InfraRed (TIR) satellite remote sensing data in synergy with meteorological data (air temperatureAT, precipitations, wind, solar radiation, etc.) were applied mainly for analyzing land surface temperature (LST) pattern and its relationship with surface landscape characteristics, assessing urban heat island (UHI), and relating urban land cover temperatures (LST). The land surface temperature, a key parameter for urban thermal characteristics analysis, was also analyzed in relation with the Normalized Difference Vegetation Index (NDVI) at city level. Results show that in the metropolitan area ratio of impervious surface in Bucharest increased significantly during investigated period, the intensity of urban heat island and heat wave events being most significant. The correlation analyses revealed that, at the pixel-scale, LST and AT possessed a strong positive correlation with percent impervious surfaces and negative correlation with vegetation abundances at metropolitan scale respectively. The NDVI was significantly correlated with precipitation. The spatial average air temperatures in urban test areas rise with the expansion of the urban size.

New high-efficiency silicon solar cells

NASA Technical Reports Server (NTRS)

Daud, T.; Crotty, G. T.

1985-01-01

A design for silicon solar cells was investigated as an approach to increasing the cell open-circuit voltage and efficiency for flat-plate terrestrial photovoltaic applications. This deviates from past designs, where either the entire front surface of the cell is covered by a planar junction or the surface is textured before junction formation, which results in an even greater (up to 70%) junction area. The heavily doped front region and the junction space charge region are potential areas of high recombination for generated and injected minority carriers. The design presented reduces junction area by spreading equidiameter dot junctions across the surface of the cell, spaced about a diffusion length or less from each other. Various dot diameters and spacings allowed variations in total junction area. A simplified analysis was done to obtain a first-order design optimization. Efficiencies of up to 19% can be obtained. Cell fabrication involved extra masking steps for selective junction diffusion, and made surface passivation a key element in obtaining good collection. It also involved photolithography, with line widths down to microns. A method is demonstrated for achieving potentially high open-circuit voltages and solar-cell efficiencies.

Isotopic Analysis and Evolved Gases

NASA Technical Reports Server (NTRS)

Swindle, Timothy D.; Boynton, William V.; Chutjian, Ara; Hoffman, John H.; Jordan, Jim L.; Kargel, Jeffrey S.; McEntire, Richard W.; Nyquist, Larry

1996-01-01

Precise measurements of the chemical, elemental, and isotopic composition of planetary surface material and gases, and observed variations in these compositions, can contribute significantly to our knowledge of the source(s), ages, and evolution of solar system materials. The analyses discussed in this paper are mostly made by mass spectrometers or some other type of mass analyzer, and address three broad areas of interest: (1) atmospheric composition - isotopic, elemental, and molecular, (2) gases evolved from solids, and (3) solids. Current isotopic data on nine elements, mostly from in situ analysis, but also from meteorites and telescopic observations are summarized. Potential instruments for isotopic analysis of lunar, Martian, Venusian, Mercury, and Pluto surfaces, along with asteroid, cometary and icy satellites, surfaces are discussed.

NASA diagonal-braked test vehicle evaluation of traction characteristics of grooved and ungrooved runway surfaces at Miami International Airport, Miami, Florida, 8-9 May 1973

NASA Technical Reports Server (NTRS)

Horne, W. B.

1977-01-01

Two runways were evaluated under artificially wetted conditions with the NASA diagonal-braked vehicle (DBV). Results of the evaluation which included a pavement drainage analysis, a pavement skid resistance analysis, and a DBV wet/dry stopping distance ratio analysis indicated that the ungrooved runway surfaces had poor water drainage characteristics and poor skid resistance under wet conditions at high speeds especially in rubbercoated areas of the runways. Grooving runways to a transverse 1-1/4 x 1/4 x 1/4 inch pattern greatly improved both the water drainage and pavement skid resistance capability of these asphaltic concrete surfaces.

Trend-surface analysis of morphometric parameters: A case study in southeastern Brazil

NASA Astrophysics Data System (ADS)

Grohmann, Carlos Henrique

2005-10-01

Trend-surface analysis was carried out on data from morphometric parameters isobase and hydraulic gradient. The study area, located in the eastern border of Quadrilátero Ferrífero, southeastern Brazil, presents four main geomorphological units, one characterized by fluvial dissection, two of mountainous relief, with a scarp of hundreds of meters of fall between them, and a flat plateau in the central portion of the fluvially dissected terrains. Morphometric maps were evaluated in GRASS-GIS and statistics were made on R statistical language, using the spatial package. Analysis of variance (ANOVA) was made to test the significance of each surface and the significance of increasing polynomial degree. The best results were achieved with sixth-order surface for isobase and second-order surface for hydraulic gradient. Shape and orientation of residual maps contours for selected trends were compared with structures inferred from several morphometric maps, and a good correlation is present.

Determining Surface Roughness in Urban Areas Using Lidar Data

NASA Technical Reports Server (NTRS)

Holland, Donald

2009-01-01

An automated procedure has been developed to derive relevant factors, which can increase the ability to produce objective, repeatable methods for determining aerodynamic surface roughness. Aerodynamic surface roughness is used for many applications, like atmospheric dispersive models and wind-damage models. For this technique, existing lidar data was used that was originally collected for terrain analysis, and demonstrated that surface roughness values can be automatically derived, and then subsequently utilized in disaster-management and homeland security models. The developed lidar-processing algorithm effectively distinguishes buildings from trees and characterizes their size, density, orientation, and spacing (see figure); all of these variables are parameters that are required to calculate the estimated surface roughness for a specified area. By using this algorithm, aerodynamic surface roughness values in urban areas can then be extracted automatically. The user can also adjust the algorithm for local conditions and lidar characteristics, like summer/winter vegetation and dense/sparse lidar point spacing. Additionally, the user can also survey variations in surface roughness that occurs due to wind direction; for example, during a hurricane, when wind direction can change dramatically, this variable can be extremely significant. In its current state, the algorithm calculates an estimated surface roughness for a square kilometer area; techniques using the lidar data to calculate the surface roughness for a point, whereby only roughness elements that are upstream from the point of interest are used and the wind direction is a vital concern, are being investigated. This technological advancement will improve the reliability and accuracy of models that use and incorporate surface roughness.

Estimated Flood Discharges and Map of Flood-Inundated Areas for Omaha Creek, near Homer, Nebraska, 2005

USGS Publications Warehouse

Dietsch, Benjamin J.; Wilson, Richard C.; Strauch, Kellan R.

2008-01-01

Repeated flooding of Omaha Creek has caused damage in the Village of Homer. Long-term degradation and bridge scouring have changed substantially the channel characteristics of Omaha Creek. Flood-plain managers, planners, homeowners, and others rely on maps to identify areas at risk of being inundated. To identify areas at risk for inundation by a flood having a 1-percent annual probability, maps were created using topographic data and water-surface elevations resulting from hydrologic and hydraulic analyses. The hydrologic analysis for the Omaha Creek study area was performed using historical peak flows obtained from the U.S. Geological Survey streamflow gage (station number 06601000). Flood frequency and magnitude were estimated using the PEAKFQ Log-Pearson Type III analysis software. The U.S. Army Corps of Engineers' Hydrologic Engineering Center River Analysis System, version 3.1.3, software was used to simulate the water-surface elevation for flood events. The calibrated model was used to compute streamflow-gage stages and inundation elevations for the discharges corresponding to floods of selected probabilities. Results of the hydrologic and hydraulic analyses indicated that flood inundation elevations are substantially lower than from a previous study.

New England salt marsh pools: A quantitative analysis of geomorphic and geographic features

USGS Publications Warehouse

Adamowicz, S.C.; Roman, C.T.

2005-01-01

New England salt marsh pools provide important wildlife habitat and are the object of on-going salt marsh restoration projects; however, they have not been quantified in terms of their basic geomorphic and geographic traits. An examination of 32 ditched and unditched salt marshes from the Connecticut shore of Long Island Sound to southern Maine, USA, revealed that pools from ditched and unditched marshes had similar average sizes of about 200 m2, averaged 29 cm in depth, and were located about 11 m from the nearest tidal flow. Unditched marshes had 3 times the density (13 pools/ha), 2.5 times the pool coverage (83 m pool/km transect), and 4 times the total pool surface area per hectare (913 m2 pool/ha salt marsh) of ditched sites. Linear regression analysis demonstrated that an increasing density of ditches (m ditch/ha salt marsh) was negatively correlated with pool density and total pool surface area per hectare. Creek density was positively correlated with these variables. Thus, it was not the mere presence of drainage channels that were associated with low numbers of pools, but their type (ditch versus creek) and abundance. Tidal range was not correlated with pool density or total pool surface area, while marsh latitude had only a weak relationship to total pool surface area per hectare. Pools should be incorporated into salt marsh restoration planning, and the parameters quantified here may be used as initial design targets.

Analysis of Instrumentation Selection and Placement to Monitor the Hydrologic Performance of Permeable Pavement Systems and Bioinfiltration Areas at the Edison Environmental Center in New Jersey

EPA Science Inventory

In 2009, the U.S. Environmental Protection Agency constructed a 0.4-ha (1-ac) parking lot surfaced with three different permeable pavement types (interlocking concrete pavers, porous concrete, and porous asphalt) and six bioinfiltration areas with three different drainage area to...

Thyroid Volume and Its Relation to Anthropometric Measures in a Healthy Cuban Population

PubMed Central

Turcios, Silvia; Lence-Anta, Juan J.; Santana, Jose-Luis; Pereda, Celia M.; Velasco, Milagros; Chappe, Mae; Infante, Idalmis; Bustillo, Marlene; García, Anabel; Clero, Enora; Maillard, Stephane; Rodriguez, Regla; Xhaard, Constance; Ren, Yan; Rubino, Carole; Ortiz, Rosa M.; de Vathaire, Florent

2015-01-01

Objectives The aim of this study was to describe the thyroid volume in healthy adults by ultrasound and to correlate this volume with some anthropometric measures and other differentiated thyroid cancer risk factors. Study Design Thyroid volume and anthropometric measures were recorded in a sample of 100 healthy adults, including 21 men and 79 women aged 18-50 years, living in a non-iodine-deficient area of Havana city. Results The average thyroid volume was 6.6 ± 0.26 ml; it was higher in men (7.3 ml) than in women (6.4 ml; p = 0.15). In the univariate analysis, thyroid volume was correlated with all anthropometric measures, but in the multivariate analysis, body surface area was found to be the only significant anthropometric parameter. Thyroid volume was also higher in current or former smokers and in persons with blood group AB or B. Conclusion Specific reference values of thyroid volume as a function of body surface area could be used for evaluating thyroid volume in clinical practice. The relation between body surface area and thyroid volume is coherent with what is known about the relation of thyroid volume to thyroid cancer risk, but the same is not true about the relation between thyroid volume and smoking habit. PMID:25960963

A global analysis of the urban heat island effect based on multisensor satellite data

NASA Astrophysics Data System (ADS)

Xiao, J.; Frolking, S. E.; Milliman, T. E.; Schneider, A.; Friedl, M. A.

2017-12-01

Human population is rapidly urbanizing. In much of the world, cities are prone to hotter weather than surrounding rural areas - so-called `urban heat islands' - and this effect can have mortal consequences during heat waves. During the daytime, when the surface energy balance is driven by incoming solar radiation, the magnitude of urban warming is strongly influenced by surface albedo and the capacity to evaporate water (i.e., there is a strong relationship between vegetated land fraction and the ratio of sensible to latent heat loss or Bowen ratio). At nighttime, urban cooling is often inhibited by the thermal inertia of the built environment and anthropogenic heat exhaust from building and transportation energy use. We evaluated a suite of global remote sensing data sets representing a range of urban characteristics against MODIS-derived land-surface temperature differences between urban and surrounding rural areas. We included two new urban datasets in this analysis - MODIS-derived change in global urban extent and global urban microwave backscatter - along with several MODIS standard products and DMSP/OLS nighttime lights time series data. The global analysis spanned a range of urban characteristics that likely influence the magnitude of daytime and/or nighttime urban heat islands - urban size, population density, building density, state of development, impervious fraction, eco-climatic setting. Specifically, we developed new satellite datasets and synthesizing these with existing satellite data into a global database of urban land surface parameters, used two MODIS land surface temperature products to generate time series of daytime and nighttime urban heat island effects for 30 large cities across the globe, and empirically analyzed these data to determine specifically which remote sensing-based characterizations of global urban areas have explanatory power with regard to both daytime and nighttime urban heat islands.

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

Change Analysis of Laser Scans of Laboratory Rock Slopes Subject to Wave Attack Testing

NASA Astrophysics Data System (ADS)

Shen, Y.; Lindenbergh, R.; Hofland, B.; Kramer, R.

2017-09-01

For better understanding how coastal structures with gentle slopes behave during high energy events, a wave attack experiment representing a storm of 3000 waves was performed in a flume facility. Two setups with different steepness of slope were compared under the same conditions. In order to quantify changes in the rock slopes after the wave attack, a terrestrial laser scanner was used to obtain 3D coordinates of the rock surface before and after each experiment. Next, through a series of processing steps, the point clouds were converted to a suitable 2D raster for change analysis. This allowed to estimate detailed and quantitative change information. The results indicate that the area around the artificial coast line, defined as the intersection between sloped surface and wave surface, is most strongly affected by wave attacks. As the distances from the sloped surface to the waves are shorter, changes for the mildly sloped surface, slope 1 (1 : 10), are distributed over a larger area compared to the changes for the more steeply sloped surface, slope 2 (1 : 5). The results of this experiment show that terrestrial laser scanning is an effective and feasible method for change analysis of rock slopes in a laboratory setting. Most striking results from a process point of view is that the transport direction of the rocks change between the two different slopes: from seaward transport for the steeper slope to landward transport for the milder slope.

Analysis of relationships between land surface temperature and land use changes in the Yellow River Delta

NASA Astrophysics Data System (ADS)

Ning, Jicai; Gao, Zhiqiang; Meng, Ran; Xu, Fuxiang; Gao, Meng

2018-06-01

This study analyzed land use and land cover changes and their impact on land surface temperature using Landsat 5 Thematic Mapper and Landsat 8 Operational Land Imager and Thermal Infrared Sensor imagery of the Yellow River Delta. Six Landsat images comprising two time series were used to calculate the land surface temperature and correlated vegetation indices. The Yellow River Delta area has expanded substantially because of the deposited sediment carried from upstream reaches of the river. Between 1986 and 2015, approximately 35% of the land use area of the Yellow River Delta has been transformed into salterns and aquaculture ponds. Overall, land use conversion has occurred primarily from poorly utilized land into highly utilized land. To analyze the variation of land surface temperature, a mono-window algorithm was applied to retrieve the regional land surface temperature. The results showed bilinear correlation between land surface temperature and the vegetation indices (i.e., Normalized Difference Vegetation Index, Adjusted-Normalized Vegetation Index, Soil-Adjusted Vegetation Index, and Modified Soil-Adjusted Vegetation Index). Generally, values of the vegetation indices greater than the inflection point mean the land surface temperature and the vegetation indices are correlated negatively, and vice versa. Land surface temperature in coastal areas is affected considerably by local seawater temperature and weather conditions.

Tailored Rh surface facilitates, enhancement of Raman scattering in trimetallic AuPt core/Rh shell composites: Experimental and theoretical evidences

NASA Astrophysics Data System (ADS)

Loganathan, B.; Chandraboss, V. L.; Senthilvelan, S.; Karthikeyan, B.

2016-01-01

We present a detailed analysis of surface-enhanced Raman scattering of 7-azaindole and L-cysteine adsorbed on a tailored Rh surface by using experimental and density functional theoretical (DFT) calculations. DFT with the B3LYP/Lanl2DZ basis set was used for the optimization of the ground state geometries and simulation of the surface-enhanced Raman spectrum of probe molecules adsorbed on Rh6 cluster. 7-azaindole and L-cysteine adsorption at the shell interface was ascertained from first-principles. In addition, characterization of synthesized trimetallic AuPt core/Rh shell colloidal nanocomposites has been analyzed by UV-visible spectroscopy, high-resolution transmission and scanning electron microscopy, selected area electron diffraction pattern analysis, energy-dispersive X-ray spectroscopy, atomic force, confocal Raman microscopy, FT-Raman and surface-enhanced Raman spectroscopic analysis. This analysis serves as the first step in gaining an accurate understanding of specific interactions at the interface of organic and biomolecules and to gain knowledge on the surface composition of trimetallic Au/Pt/Rh colloidal nanocomposites.

Estimation of Surface Deformation due to Pasni Earthquake Using SAR Interferometry

NASA Astrophysics Data System (ADS)

Ali, M.; Shahzad, M. I.; Nazeer, M.; Kazmi, J. H.

2018-04-01

Earthquake cause ground deformation in sedimented surface areas like Pasni and that is a hazard. Such earthquake induced ground displacements can seriously damage building structures. On 7 February 2017, an earthquake with 6.3 magnitudes strike near to Pasni. We have successfully distinguished widely spread ground displacements for the Pasni earthquake by using InSAR-based analysis with Sentinel-1 satellite C-band data. The maps of surface displacement field resulting from the earthquake are generated. Sentinel-1 Wide Swath data acquired from 9 December 2016 to 28 February 2017 was used to generate displacement map. The interferogram revealed the area of deformation. The comparison map of interferometric vertical displacement in different time period was treated as an evidence of deformation caused by earthquake. Profile graphs of interferogram were created to estimate the vertical displacement range and trend. Pasni lies in strong earthquake magnitude effected area. The major surface deformation areas are divided into different zones based on significance of deformation. The average displacement in Pasni is estimated about 250 mm. Maximum pasni area is uplifted by earthquake and maximum uplifting occurs was about 1200 mm. Some of areas was subsidized like the areas near to shoreline and maximum subsidence was estimated about 1500 mm. Pasni is facing many problems due to increasing sea water intrusion under prevailing climatic change where land deformation due to a strong earthquake can augment its vulnerability.

Sampling theory and automated simulations for vertical sections, applied to human brain.

PubMed

Cruz-Orive, L M; Gelšvartas, J; Roberts, N

2014-02-01

In recent years, there have been substantial developments in both magnetic resonance imaging techniques and automatic image analysis software. The purpose of this paper is to develop stereological image sampling theory (i.e. unbiased sampling rules) that can be used by image analysts for estimating geometric quantities such as surface area and volume, and to illustrate its implementation. The methods will ideally be applied automatically on segmented, properly sampled 2D images - although convenient manual application is always an option - and they are of wide applicability in many disciplines. In particular, the vertical sections design to estimate surface area is described in detail and applied to estimate the area of the pial surface and of the boundary between cortex and underlying white matter (i.e. subcortical surface area). For completeness, cortical volume and mean cortical thickness are also estimated. The aforementioned surfaces were triangulated in 3D with the aid of FreeSurfer software, which provided accurate surface area measures that served as gold standards. Furthermore, a software was developed to produce digitized trace curves of the triangulated target surfaces automatically from virtual sections. From such traces, a new method (called the 'lambda method') is presented to estimate surface area automatically. In addition, with the new software, intersections could be counted automatically between the relevant surface traces and a cycloid test grid for the classical design. This capability, together with the aforementioned gold standard, enabled us to thoroughly check the performance and the variability of the different estimators by Monte Carlo simulations for studying the human brain. In particular, new methods are offered to split the total error variance into the orientations, sectioning and cycloid components. The latter prediction was hitherto unavailable--one is proposed here and checked by way of simulations on a given set of digitized vertical sections with automatically superimposed cycloid grids of three different sizes. Concrete and detailed recommendations are given to implement the methods. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

Biostereometric analysis of body form - The second manned Skylab mission

NASA Technical Reports Server (NTRS)

Whittle, M. W.; Herron, R. E.; Cuzzi, J. R.

1976-01-01

Results of biostereometric analyses of the body form of the Skylab 3 crew before and after flight. The Cartesian coordinates of numerous points on the body surface were derived by stereophotogrammetry, and mathematical analysis of the coordinate description allowed computation of the surface area and volume of the body, the volume of body segments, and the area and shape of cross sections. The weight loss in all three crew members was accompanied by a loss in volume distributed between the trunk and legs, with the legs showing the greatest proportional loss. The observed loss of volume apparently resulted from a combined loss of fluid in the abdomen and legs, of muscle in the legs and paraspinal region, and of fat in the abdomen and buttocks.

An operational air quality objective analysis of surface pollutants

NASA Astrophysics Data System (ADS)

Menard, R.; Robichaud, A.

2013-05-01

As of December 2012 a surface analysis of O3, PM2.5 at a resolution of 10 km over Canada and USA has become an operational product of Environment Canada. Analyses based an optimum interpolation scheme adapted to the variability of surface pollutant is run each hour. We will briefly discuss the specifics of the scheme, the technical implementation that lead to an operational implementation, a description and validation of the product as it stands today. An analysis of NO2 and a map of an air quality health index is also under way. We are now developing a high resolution analysis, 2.5 km over major cities over the Montreal-Toronto area and over the Oil sands region. The effect of state-dependent error covariance modeling will be present with some early results of the high resolutions analysis/assimilation.

Using pan-sharpened high resolution satellite data to improve impervious surfaces estimation

NASA Astrophysics Data System (ADS)

Xu, Ru; Zhang, Hongsheng; Wang, Ting; Lin, Hui

2017-05-01

Impervious surface is an important environmental and socio-economic indicator for numerous urban studies. While a large number of researches have been conducted to estimate the area and distribution of impervious surface from satellite data, the accuracy for impervious surface estimation (ISE) is insufficient due to high diversity of urban land cover types. This study evaluated the use of panchromatic (PAN) data in very high resolution satellite image for improving the accuracy of ISE by various pan-sharpening approaches, with a further comprehensive analysis of its scale effects. Three benchmark pan-sharpening approaches, Gram-Schmidt (GS), PANSHARP and principal component analysis (PCA) were applied to WorldView-2 in three spots of Hong Kong. The on-screen digitization were carried out based on Google Map and the results were viewed as referenced impervious surfaces. The referenced impervious surfaces and the ISE results were then re-scaled to various spatial resolutions to obtain the percentage of impervious surfaces. The correlation coefficient (CC) and root mean square error (RMSE) were adopted as the quantitative indicator to assess the accuracy. The accuracy differences between three research areas were further illustrated by the average local variance (ALV) which was used for landscape pattern analysis. The experimental results suggested that 1) three research regions have various landscape patterns; 2) ISE accuracy extracted from pan-sharpened data was better than ISE from original multispectral (MS) data; and 3) this improvement has a noticeable scale effects with various resolutions. The improvement was reduced slightly as the resolution became coarser.

Actuated coordinated signalized system : Phase I oversaturated conditions : Phase II cycle-by-cycle analysis

DOT National Transportation Integrated Search

2001-11-01

The role of the vehicle is more important today than ever before in history, and its increased usage has led to congestion, not only in urban metropolitan areas, but also in rural small and mid-size cities. In most areas, the surface transportation n...

Correlation between surface topography and lubricant migration in steel sheets for the autobody manufacturing process

NASA Astrophysics Data System (ADS)

Benati, F.; Sacerdotti, F.; Griffiths, B. J.; Butler, C.; Karila, J. M.; Vermeulen, M.; Holtkamp, H.; Gatti, S.

2002-05-01

Material for the production of autobody panels is usually dispatched in the form of coils. Because of their weight, they tend to `compress' the lubricant applied for rust protection and some of it leaks from the coil. Those areas affected by lubricant starvation are known as `dry-spots' and are a cause of a number of product rejections during the subsequent forming operation. A test was deployed with the combined work of Ocas, CORUS IJmuiden and Renault that proved that surface topography controls, amongst other factors, affects lubricant migration. The test consists of compressing a stack of lubricated steel sheets at known pressure for a known time using different lubricants in different amounts. It was observed that, because of the `compression', the lubricant tends to migrate to the side of the sheet, and its migration was quantified using a Fischer Betascope MMS module. Analysis consisted of analysis of variance on several designs of experiments and subsequent correlation with surface topography 3D parameters. These experiments showed the importance of standard amplitude surface parameters and new closed area surface parameters to characterize lubricant migration under pressure.

One Step Assembly of Thin Films of Carbon Nanotubes on Screen Printed Interface for Electrochemical Aptasensing of Breast Cancer Biomarker.

PubMed

Nawaz, Muhammad Azhar Hayat; Rauf, Sajid; Catanante, Gaelle; Nawaz, Mian Hasnain; Nunes, Gilvanda; Marty, Jean Louis; Hayat, Akhtar

2016-10-06

Thin films of organic moiety functionalized carbon nanotubes (CNTs) from a very well-dispersed aqueous solution were designed on a screen printed transducer surface through a single step directed assembly methodology. Very high density of CNTs was obtained on the screen printed electrode surface, with the formation of a thin and uniform layer on transducer substrate. Functionalized CNTs were characterized by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Brunauer-Emmett- Teller (BET) surface area analyzer methodologies, while CNT coated screen printed transducer platform was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed methodology makes use of a minimum amount of CNTs and toxic solvents, and is successfully demonstrated to form thin films over macroscopic areas of screen printed carbon transducer surface. The CNT coated screen printed transducer surface was integrated in the fabrication of electrochemical aptasensors for breast cancer biomarker analysis. This CNT coated platform can be applied to immobilize enzymes, antibodies and DNA in the construction of biosensor for a broad spectrum of applications.

One Step Assembly of Thin Films of Carbon Nanotubes on Screen Printed Interface for Electrochemical Aptasensing of Breast Cancer Biomarker

PubMed Central

Nawaz, Muhammad Azhar Hayat; Rauf, Sajid; Catanante, Gaelle; Nawaz, Mian Hasnain; Nunes, Gilvanda; Louis Marty, Jean; Hayat, Akhtar

2016-01-01

Thin films of organic moiety functionalized carbon nanotubes (CNTs) from a very well-dispersed aqueous solution were designed on a screen printed transducer surface through a single step directed assembly methodology. Very high density of CNTs was obtained on the screen printed electrode surface, with the formation of a thin and uniform layer on transducer substrate. Functionalized CNTs were characterized by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller (BET) surface area analyzer methodologies, while CNT coated screen printed transducer platform was analyzed by scanning electron microscopy (SEM), atomic force microscopy (AFM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed methodology makes use of a minimum amount of CNTs and toxic solvents, and is successfully demonstrated to form thin films over macroscopic areas of screen printed carbon transducer surface. The CNT coated screen printed transducer surface was integrated in the fabrication of electrochemical aptasensors for breast cancer biomarker analysis. This CNT coated platform can be applied to immobilize enzymes, antibodies and DNA in the construction of biosensor for a broad spectrum of applications. PMID:27782067

Applications of Computer Graphics in Engineering

NASA Technical Reports Server (NTRS)

1975-01-01

Various applications of interactive computer graphics to the following areas of science and engineering were described: design and analysis of structures, configuration geometry, animation, flutter analysis, design and manufacturing, aircraft design and integration, wind tunnel data analysis, architecture and construction, flight simulation, hydrodynamics, curve and surface fitting, gas turbine engine design, analysis, and manufacturing, packaging of printed circuit boards, spacecraft design.

Evaluation of high temperature structural adhesives for extended service. [supersonic cruise aircraft research

NASA Technical Reports Server (NTRS)

Hill, S. G.

1981-01-01

Eight different Ti-6Al-4V surface treatments were investigated for each of 10 candidate resins. Primers (two for each resin) were studied for appropriate cure and thickness and initial evaluation of bond joints began using various combinations of the adhesive resins and surface treatments. Surface failure areas of bonded titanium coupons were analyzed by electron microscopy and surface chemical analysis techniques. Results of surface characterization and failure analysis are described for lap shear bond joints occurring with adhesive systems consisting of: (1) LARC-13 adhesive, Pasa jell surface treatment; (2) LARC-13 adhesive, 10 volt CAA treatment; (3) PPQ adhesive, 10 volt CAA treatment; and (4) PPQ adhesive, 5 volt CAA treatment. The failure analysis concentrated on the 10,000 hr 505K (450 F) exposed specimens which exhibited adhesive failure. Environmental exposure data being generated on the PPQ-10 volt CAA and the LARC-TPI-10 volt CAA adhesive systems is included.

Monitoring of surface movement in a large area of the open pit iron mines (Carajás, Brazil) based on A-DInSAR techniques using TerraSAR-X data

NASA Astrophysics Data System (ADS)

Mura, José C.; Paradella, Waldir R.; Gama, Fabio F.; Silva, Guilherme G.

2016-10-01

PSI (Persistent Scatterer Interferometry) analysis of large area is always a challenging task regarding the removal of the atmospheric phase component. This work presents an investigation of ground deformation measurements based on a combination of DInSAR Time-Series (DTS) and PSI techniques, applied in a large area of open pit iron mines located in Carajás (Brazilian Amazon Region), aiming at detect high rates of linear and nonlinear ground deformation. These mines have presented a historical of instability and surface monitoring measurements over sectors of the mines (pit walls) have been carried out based on ground based radar and total station (prisms). By using a priori information regarding the topographic phase error and phase displacement model derived from DTS, temporal phase unwrapping in the PSI processing and the removal of the atmospheric phases can be performed more efficiently. A set of 33 TerraSAR-X-1 images, acquired during the period from March 2012 to April 2013, was used to perform this investigation. The DTS analysis was carried out on a stack of multi-look unwrapped interferogram using an extension of SVD to obtain the Least-Square solution. The height errors and deformation rates provided by the DTS approach were subtracted from the stack of interferogram to perform the PSI analysis. This procedure improved the capability of the PSI analysis to detect high rates of deformation as well as increased the numbers of point density of the final results. The proposed methodology showed good results for monitoring surface displacement in a large mining area, which is located in a rain forest environment, providing very useful information about the ground movement for planning and risks control.

Nitrogen-doped hierarchical lamellar porous carbon synthesized from the fish scale as support material for platinum nanoparticle electrocatalyst toward the oxygen reduction reaction.

PubMed

Liu, Haijing; Cao, Yinliang; Wang, Feng; Huang, Yaqin

2014-01-22

Novel hierarchical lamellar porous carbon (HLPC) with high BET specific surface area of 2730 m(2) g(-1) and doped by nitrogen atoms has been synthesized from the fish scale without any post-synthesis treatment, and applied to support the platinum (Pt) nanoparticle (NP) catalysts (Pt/HLPC). The Pt NPs could be highly dispersed on the porous surface of HLPC with a narrow size distribution centered at ca. 2.0 nm. The results of the electrochemical analysis reveal that the electrochemical active surface area (ECSA) of Pt/HLPC is larger than the Pt NP electrocatalyst supported on the carbon black (Pt/Vulcan XC-72). Compared with the Pt/Vulcan XC-72, the Pt/HLPC exhibits larger current density, lower overpotential, and enhanced catalytic activity toward the oxygen reduction reaction (ORR) through the direct four-electron pathway. The improved catalytic activity is mainly attributed to the high BET specific surface area, hierarchical porous structures and the nitrogen-doped surface property of HLPC, indicating the superiority of HLPC as a promising support material for the ORR electrocatalysts.

Grain boundaries at the surface of consolidated MgO nanocrystals and acid-base functionality.

PubMed

Vingurt, Dima; Fuks, David; Landau, Miron V; Vidruk, Roxana; Herskowitz, Moti

2013-09-21

The increase of the surface basicity-acidity of MgO material by factors of 1.8-3.0 due to consolidation of its nanocrystals was demonstrated by the indicator titration. It was shown that the parallel increase of surface acidity and basicity is attributed to the formation of grain boundaries (GB) after MgO aerogel densification. A simple model predicting the increase of surface acidity-basicity of MgO that correlates with the results of direct measurements was proposed. The model is based on the study of the fine atomic structure at GB surface areas in consolidated MgO nanocrystals in the framework of Density Functional Theory. It is found that the displacements of coordinatively unsaturated surface ions near the GB are significant at the distances ~3-4 atomic layers from the geometrical contact plane between nanocrystals. The detailed analysis of atomic positions inside GB demonstrated the coordination deficiency of surface atoms at the GB areas leading to the formation of stretched bonds and to creation of low coordinated surface ions due to splitting of coordination numbers of surface atoms belonging to GB areas. Density of states for electrons shows the existence of additional states in the band gap close to the bottom of the conduction band. The adsorption energy of CO2 molecules atop oxygen atoms exposed at surface GB areas is of the same order of magnitude as that reported for oxygen atoms at crystallographic edges and corners of MgO crystals. It provides additional options for bonding of molecules at the surface of nanocrystalline MgO increasing the adsorption capacity and catalytic activity.

Extraction of Suspended Sediments from Landsat Imagery in the Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Hardin, D. M.; Drewry, M.; He, M. Y.; Ebersole, S.

2011-12-01

The Sediment Analysis Network for Decision Support (SANDS) project is utilizing enhancement methods to highlight suspended sediment in remotely sensed data and imagery of the Northern Gulf of Mexico. The analysis thus far has shown that areas of suspended sediments can be extracted from Landsat imagery. In addition, although not an original goal of SANDS, the analysis techniques have revealed oil floating on the water's surface. Detection of oil floating on the surface through remotely sensed imagery can be helpful in identifying and understanding the geographic distribution and movement of oil for environmental concerns. Data from Landsat, and MODIS were obtained from NASA Earth Science Data Centers by the Information Technology and Systems Center at the University of Alabama in Huntsville and prepared for analysis by subsetting to the region of interest and converting from HDF-EOS format (in the case of MODIS) to GeoTiff. Analysts at the Geological Survey of Alabama (GSA) working with Landsat data initially, employed enhancement methods, including false color composites, spectral ratios, and other spectral enhancements based on the mineral composition of sediments, to combinations of visible and infrared bands of data. Initial results of this approach revealed suspended sediments. The analysis technique also revealed areas of oil floating on the surface of the Gulf near Chandeleur Island immediately after Hurricane Katrina in 2005. True color Landsat imagery compares the original Landsat scene to the same region after enhancement. The areas of floating oil are clearly visible. The oil washed out from oil spills on land. This paper will present the intermediate result of the SANDS project thus far.

Correlative bacteriologic and micro-computed tomographic analysis of mandibular molar mesial canals prepared by self-adjusting file, reciproc, and twisted file systems.

PubMed

Siqueira, José F; Alves, Flávio R F; Versiani, Marco A; Rôças, Isabela N; Almeida, Bernardo M; Neves, Mônica A S; Sousa-Neto, Manoel D

2013-08-01

This ex vivo study evaluated the disinfecting and shaping ability of 3 protocols used in the preparation of mesial root canals of mandibular molars by means of correlative bacteriologic and micro-computed tomographic (μμCT) analysis. The mesial canals of extracted mandibular molars were contaminated with Enterococcus faecalis for 30 days and assigned to 3 groups based on their anatomic configuration as determined by μCT analysis according to the preparation technique (Self-Adjusting File [ReDent-Nova, Ra'anana, Israel], Reciproc [VDW, Munich, Germany], and Twisted File [SybronEndo, Orange, CA]). In all groups, 2.5% NaOCl was the irrigant. Canal samples were taken before (S1) and after instrumentation (S2), and bacterial quantification was performed using culture. Next, mesial roots were subjected to additional μCT analysis in order to evaluate shaping of the canals. All instrumentation protocols promoted a highly significant intracanal bacterial reduction (P < .001). Intergroup quantitative and qualitative comparisons disclosed no significant differences between groups (P > .05). As for shaping, no statistical difference was observed between the techniques regarding the mean percentage of volume increase, the surface area increase, the unprepared surface area, and the relative unprepared surface area (P > .05). Correlative analysis showed no statistically significant relationship between bacterial reduction and the mean percentage increase of the analyzed parameters (P > .05). The 3 instrumentation systems have similar disinfecting and shaping performance in the preparation of mesial canals of mandibular molars. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Estimation of small reservoir storage capacities in the São Francisco, Limpopo, Bandama and Volta river basins using remotely sensed surface areas

NASA Astrophysics Data System (ADS)

Rodrigues, Lineu; Senzanje, Aidan; Cecchi, Philippe; Liebe, Jens

2010-05-01

People living in areas with highly variable rainfall, experience droughts and floods and often have insecure livelihoods. Small multi-purpose reservoirs (SR) are a widely used form of infrastructures to provide people in such areas with water during the dry season, e.g. in the basins of São Francisco, Brazil, Limpopo, Zimbabwe, Bandama, Ivory Coast and Volta, Ghana. In these areas, the available natural flow in the streams is sometimes less than the flow required for water supply or irrigation, however water can be stored in times of surplus, for example, from a wet season to a dry season. Efficient water management and sound reservoir planning are hindered by the lack of information about the functioning of these reservoirs. Reservoirs in these regions were constructed in a series of projects funded by different agencies, at different times, with little or no coordination among the implementing partners. Poor record keeping and the lack of appropriate institutional support result in deficiencies of information on the capacity, operation, and maintenance of these structures. Estimating the storage capacity of dams is essential to the responsible management of water diversion. Most of SR in these basins have never been evaluated, possibly because the tools currently used for such measurement are labor-intensive, costly and time-consuming. The objective of this research was to develop methodology to estimate small reservoir capacities as a function of their remotely sensed surface areas in the São Francisco, Limpopo, Bandama and Volta basins, as a way to contribute to improve the water resource management in those catchments. Remote sensing was used to identify, localize and characterize small reservoirs. The surface area of each was calculated from satellite images. A sub-set of reservoirs was selected. For each reservoir in the sub-set, the surface area was estimated from field surveys, and storage capacity was estimated using information on reservoir surface area, depth and shape. Depth was measured using a stadia rod or a manual echosounder. For reservoirs in the sub-set, estimated surface area was used as an input into the triangulated irregular network model. With the surface area and depth, measured volume was calculated. Comparisons were made between estimates of surface area from field surveys and estimates of surface area from remote sensing. A linear regression analysis was carried out to establish the relationship between surface area and storage capacities. Within geomorphologically homogenous regions, one may expect a good correlation between the surface area, which may be determined through satellite observations, and the stored volume. Such a relation depends on the general shape of the slopes (convex, through straight, to concave). The power relationships between remotely sensed surface areas (m^2) and storage capacities of reservoirs (m^3) obtained were - Limpopo basin (Lower Mzingwane sub-catchment): Volume = 0.023083 x Area^1.3272 (R2 = 95%); Bandama basin (North of the basin in Ivory Coast): Volume = 0.00405 x Area^1.4953 (R2 = 88.9%); Volta basin (Upper East region of the Volta Basin in Ghana): Volume = 0.00857 × Area^1.43 (R2 = 97.5%); São Francisco basin (Preto river sub-catchment): Volume = 0.2643 x Area^1.1632 (R2 = 92.1%). Remote sensing was found to be a suitable means to detect small reservoirs and accurately measure their surface areas. The general relationship between measured reservoir volumes and their remotely sensed surface areas showed good accuracy for all four basins. Combining such relationships with periodical satellite-based reservoir area measurements may allow hydrologists and planners to have clear picture of water resource system in the Basins, especially in ungauged sub-basins.

Grinding efficiency of abutment tooth with both dentin and core composite resin on axial plane.

PubMed

Miho, Otoaki; Sato, Toru; Matsukubo, Takashi

2015-01-01

The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed direction were also analyzed. Using a non-ground surface as a reference, areas comprising only dentin, both dentin and core composite resin, or only core composite resin were analyzed to determine the angle of the grinding surface. Composite resins were subjected to the Vickers hardness test and scanning electron microscopy. Data were statistically analyzed using a one-way analysis of variance and multiple comparison tests. Multiple regression analysis was performed for load, feed rate, and Vickers hardness of the build-up material depending on number of runs. When grinding was performed at a constant load and feed rate, a greater grinding angle was observed in areas comprising both dentin and composite resin or only composite resin than in areas consisting of dentin alone. A correlation was found between machinability and load or feed rate in areas comprising both dentin and composite resin or composite resin alone, with a particularly high correlation being observed between machinability and load. These results suggest that great caution should be exercised in a clinical setting when the boundary between the dentin and composite resin is to be ground, as the angle of the grinding surface changes when the rotating diamond point begins grinding the composite resin.

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.

Cortical morphometry in frontoparietal and default mode networks in math-gifted adolescents.

PubMed

Navas-Sánchez, Francisco J; Carmona, Susana; Alemán-Gómez, Yasser; Sánchez-González, Javier; Guzmán-de-Villoria, Juan; Franco, Carolina; Robles, Olalla; Arango, Celso; Desco, Manuel

2016-05-01

Math-gifted subjects are characterized by above-age performance in intelligence tests, exceptional creativity, and high task commitment. Neuroimaging studies reveal enhanced functional brain organization and white matter microstructure in the frontoparietal executive network of math-gifted individuals. However, the cortical morphometry of these subjects remains largely unknown. The main goal of this study was to compare the cortical morphometry of math-gifted adolescents with that of an age- and IQ-matched control group. We used surface-based methods to perform a vertex-wise analysis of cortical thickness and surface area. Our results show that math-gifted adolescents present a thinner cortex and a larger surface area in key regions of the frontoparietal and default mode networks, which are involved in executive processing and creative thinking, respectively. The combination of reduced cortical thickness and larger surface area suggests above-age neural maturation of these networks in math-gifted individuals. Hum Brain Mapp 37:1893-1902, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Pollutant loads of surface runoff in Wuhan City Zoo, an urban tourist area.

PubMed

Zhao, Jian-wei; Shan, Bao-qing; Yin, Cheng-qing

2007-01-01

The pollutant loads of surface runoff in an urban tourist area have been investigated for two years in the Wuhan City Zoo, China. Eight sampling sites, including two woodlands, three animal yards, two roofs and one road, were selected for sampling and study. The results indicate that pollutants ranked in a predictable order of decreasing load (e.g. animal yard > roof > woodland > road), with animal yards acting as the key pollution source in the zoo. Pollutants were transported mainly by particulate form in runoff. Particulate nitrogen and particulate phosphorous accounted on average for 61%, 78% of total pollutant, respectively, over 13 monitored rainfall events. These results indicate the treatment practices should be implemented to improve particulate nutrient removal. Analysis of the M(V) curve indicate that no first flush effect existed in the surface runoff from pervious areas (e.g. woodland, animal ground yard), whereas a first flush effect was evident in runoff from impervious surfaces (e.g. animal cement yard, roof, road).

Trace metal pollution assessment in the surface sediments of nearshore area, off Calicut, southwest coast of India.

PubMed

Srinivas, Reji; Shynu, R; Sreeraj, M K; Ramachandran, K K

2017-07-15

Metal concentrations (Al, Cr, Ni, Cu, Zn, and Pb), grain size, and total organic carbon content in 29 surface sediment samples from the nearshore area off Calicut were analyzed to determine their distribution and pollution status. Surface sediments were dominantly silts with low percentage of clay and sand at nearshore and offshore areas. The mean metal concentrations were in the following order: Cr>Ni>Zn>Pb>Cu. The enrichment factor and geo-accumulation index of metals suggest that the surface sediments were not polluted by Zn and moderately polluted by Cu and Ni. By contrast, Cr and Pb showed significant enrichment levels. Results from a multivariate statistical analysis suggested that the spatial enrichment of these heavy metals was related to sediment type. Thus, the sediment distribution and their metal enrichment were mainly controlled by local hydrodynamic conditions that caused the winnowing of fine-grained sediments. Copyright © 2017. Published by Elsevier Ltd.

Sunlight reflection off the spacecraft with a solar sail on the surface of mars

NASA Astrophysics Data System (ADS)

Starinova, O. L.; Rozhkov, M. A.; Gorbunova, I. V.

2018-05-01

Modern technologies make it possible to fulfill many projects in the field of space exploration. One such project is the colonization of Mars and providing favorable conditions for living on it. Authors propose principles of functioning of the spacecraft with a solar sail, intended to create a thermal and light spot in a predetermined area of the Martian surface. This additional illumination can maintain and support certain climatic conditions on a small area where a Mars base could be located. This paper investigate the possibility of the spacecraft continuously reflect the sunlight off the solar sail on the small area of the Mars surface. The mathematical motion model in such condition of the solar sail's orientation is considered and used for motion simulation session. Moreover, the analysis of this motion is performed. Thus, were obtained parameters of the synchronic non-Keplerian orbit and spacecraft construction. In addition, were given recommendations for further applying satellites to reflect the sunlight on a planet's surface.

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

Self-Assembled Gold Nano-Ripple Formation by Gas Cluster Ion Beam Bombardment.

PubMed

Tilakaratne, Buddhi P; Chen, Quark Y; Chu, Wei-Kan

2017-09-08

In this study, we used a 30 keV argon cluster ion beam bombardment to investigate the dynamic processes during nano-ripple formation on gold surfaces. Atomic force microscope analysis shows that the gold surface has maximum roughness at an incident angle of 60° from the surface normal; moreover, at this angle, and for an applied fluence of 3 × 10 16 clusters/cm², the aspect ratio of the nano-ripple pattern is in the range of ~50%. Rutherford backscattering spectrometry analysis reveals a formation of a surface gradient due to prolonged gas cluster ion bombardment, although the surface roughness remains consistent throughout the bombarded surface area. As a result, significant mass redistribution is triggered by gas cluster ion beam bombardment at room temperature. Where mass redistribution is responsible for nano-ripple formation, the surface erosion process refines the formed nano-ripple structures.

Biochar characteristics produced from rice husks and their sorption properties for the acetanilide herbicide metolachlor.

PubMed

Wei, Lan; Huang, Yufen; Li, Yanliang; Huang, Lianxi; Mar, Nyo Nyo; Huang, Qing; Liu, Zhongzhen

2017-02-01

Rice husk biochar (RHBC) was prepared for use as adsorbents for the herbicide metolachlor. The characteristics and sorption properties of metolachlor adsorbed by the RHBC prepared at different pyrolysis temperatures were determined by analysis of physico-chemical characteristics, Fourier transform infrared spectroscopy (FTIR), Boehm titration, scanning electron microscopy (SEM), and thermodynamics and kinetics adsorption. With increasing pyrolysis temperature, the RHBC surface area greatly increased (from 2.57 to 53.08 m 2  g -1 ). RHBC produced at the highest temperature (750 °C) had the greatest surface area; SEM also showed the formation of a porous surface on RH-750 biochar. The sorption capacity of RHBC also increased significantly with increasing pyrolysis temperature and was characterized by the Freundlich constant K f for the adsorption capacity increasing from 125.17-269.46 (pyrolysis at 300 °C) to 339.94-765.24 (pyrolysis at 750 °C). The results indicated that the surface area and pore diameter of RHBC produced with high pyrolysis temperature (i.e., 750 °C) had the greatest impact on the adsorption of metolachlor. The FTIR, Boehm titration, and SEM analysis showed that the greatest number of surface groups were on RHBC produced at the lowest temperature (300 °C). The biochars produced at different pyrolysis temperatures had different mechanisms of adsorbing metolachlor, which exhibited a transition from hydrogen bonds dominant at low pyrolytic temperature to pore-filling dominant at higher pyrolytic temperature.

Edge profiles and limiter tests in Extrap T2

NASA Astrophysics Data System (ADS)

Bergsåker, H.; Hedin, G.; Ilyinsky, L.; Larsson, D.; Möller, A.

New edge profile measurements, including calorimetric measurements of the parallel heat flux, were made in Extrap T2. Test limiters of pure molybdenum and the TZM molybdenum alloy have been exposed in the edge plasma. The surface damage was studied, mainly by microscopy. Tungsten coated graphite probes were also exposed, and the surfaces were studied by microscopy, ion beam analysis and XPS. In this case cracking and mixing of carbon and tungsten at the interface was observed in the most heated areas, whereas carbide formation at the surface was seen in less heated areas. In these tests pure Mo generally fared better than TZM, and thin and cleaner coatings fared better than thicker and less clean.

Micro patterned surfaces: an effective tool for long term digital holographic microscopy cell imaging

NASA Astrophysics Data System (ADS)

Mues, Sarah; Lilge, Inga; Schönherr, Holger; Kemper, Björn; Schnekenburger, Jürgen

2017-02-01

The major problem of Digital Holographic Microscopy (DHM) long term live cell imaging is that over time most of the tracked cells move out of the image area and other ones move in. Therefore, most of the cells are lost for the evaluation of individual cellular processes. Here, we present an effective solution for this crucial problem of long-term microscopic live cell analysis. We have generated functionalized slides containing areas of 250 μm per 200 μm. These micropatterned biointerfaces consist of passivating polyaclrylamide brushes (PAAm). Inner areas are backfilled with octadecanthiol (ODT), which allows cell attachment. The fouling properties of these surfaces are highly controllable and therefore the defined areas designed for the size our microscopic image areas were effective in keeping all cells inside the rectangles over the selected imaging period.

Reconstruction of the thermal environment evolution in urban areas from underground temperature distribution.

PubMed

Yamano, Makoto; Goto, Shusaku; Miyakoshi, Akinobu; Hamamoto, Hideki; Lubis, Rachmat Fajar; Monyrath, Vuthy; Taniguchi, Makoto

2009-04-15

It is possible to estimate the ground surface temperature (GST) history of the past several hundred years from temperature profiles measured in boreholes because the temporal variation in GST propagates into the subsurface by thermal diffusion. This "geothermal method" of reconstructing GST histories can be applied to studies of thermal environment evolution in urban areas, including the development of "heat islands." Temperatures in boreholes were logged at 102 sites in Bangkok, Jakarta, Taipei, Seoul and their surrounding areas in 2004 to 2007. The effects of recent surface warming can be recognized in the shapes of most of the obtained temperature profiles. The preliminary results of reconstruction of GST histories through inversion analysis show that GST increased significantly in the last century. Existing temperature profile data for the areas in and around Tokyo and Osaka can also be used to reconstruct GST histories. Because most of these cities are located on alluvial plains in relatively humid areas, it is necessary to use a model with groundwater flow and a layered subsurface structure for reconstruction analysis. Long-term records of subsurface temperatures at multiple depths may demonstrate how the GST variation propagates downward through formations. Time series data provide information on the mechanism of heat transfer (conduction or advection) and the thermal diffusivity. Long-term temperature monitoring has been carried out in a borehole located on the coast of Lake Biwa, Japan. Temperatures at 30 and 40 m below the ground surface were measured for 4 years and 2 years, respectively, with a resolution of 1 mK. The obtained records indicate steady increases at both depths with different rates, which is probably the result of some recent thermal event(s) near the surface. Borehole temperatures have also been monitored at selected sites in Bangkok, Jakarta, and Taiwan.

A comparison of spectral mixture analysis an NDVI for ascertaining ecological variables

NASA Technical Reports Server (NTRS)

Wessman, Carol A.; Bateson, C. Ann; Curtiss, Brian; Benning, Tracy L.

1993-01-01

In this study, we compare the performance of spectral mixture analysis to the Normalized Difference Vegetation Index (NDVI) in detecting change in a grassland across topographically-induced nutrient gradients and different management schemes. The Konza Prairie Research Natural Area, Kansas, is a relatively homogeneous tallgrass prairie in which change in vegetation productivity occurs with respect to topographic positions in each watershed. The area is the site of long-term studies of the influence of fire and grazing on tallgrass production and was the site of the First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE) from 1987 to 1989. Vegetation indices such as NDVI are commonly used with imagery collected in few (less than 10) spectral bands. However, the use of only two bands (e.g. NDVI) does not adequately account for the complex of signals making up most surface reflectance. Influences from background spectral variation and spatial heterogeneity may confound the direct relationship with biological or biophysical variables. High dimensional multispectral data allows for the application position of techniques such as derivative analysis and spectral curve fitting, thereby increasing the probability of successfully modeling the reflectance from mixed surfaces. The higher number of bands permits unmixing of a greater number of surface components, separating the vegetation signal for further analyses relevant to biological variables.

Measurement of In Vivo Three-Dimensional Corneal Cell Density and Size Using Two-Photon Imaging in C57BL/6 Mice.

PubMed

Zhang, Hongmin; He, Siyu; Liu, Susu; Xie, Yanting; Chen, Guoming; Zhang, Junjie; Sun, Shengtao; Liang, David; Wang, Liya

2016-04-01

To measure the cell size and cell density in five layers of the central cornea in the widely used inbred C57BL/6 mouse strain using in vivo three-dimensional (3D) two-photon (2PH) imaging. Corneas were scanned using a 2PH laser scanning fluorescence microscope after staining with plasma membrane stain and Hoechst 33342. Good quality 3D images were selected for the cell density and cell size analysis. Cell density was determined by counting the cell nuclei in a predefined cube of 3D images. Cell size measurements, including cell surface area, cell volume, nuclear surface area and nuclear volume, were automatically quantified using the Imaris software. The cell and nuclear surface-area-to-volume ratio (S:V ratio) and the cell nuclear-cytoplasmic ratio (N:C ratio) were calculated. The highest cell density was observed in the basal epithelium and the lowest in the posterior stroma. The highest cell surface area was found in the anterior stroma, and the highest cell volume was observed in the superficial epithelium. The lowest cell surface area and cell volume were both found in the basal epithelium. The highest S:V ratio was observed in the basal epithelium and the lowest in the superficial epithelium. The highest cell nuclear surface area and volume were both observed in the superficial epithelium and the lowest in the basal epithelium. The highest cell nuclear S:V ratio was observed in the basal epithelium and the lowest in the superficial epithelium. The highest N:C ratio was found in the basal epithelial cells and the lowest in the posterior keratocytes. We are the first to quantify the cell density and size parameters, including cell surface area and volume, cell nuclear surface area and volume, and the S:V ratio, in the five layers of the central cornea. These data provide important cell morphology features for the study of corneal physiology, pathology and disease in mice, particularly in C57BL/6 mice.

Optical mapping of surface roughness by implementation of a spatial light modulator

NASA Astrophysics Data System (ADS)

Aulbach, Laura; Pöller, Franziska; Lu, Min; Wang, Shengjia; Koch, Alexander W.

2017-08-01

It is well-known that the surface roughness of materials plays an important role in the operation and performance of technological systems. The roughness influences key parameters, such as friction and wear, and is directly connected to the functionality and durability of the respective system. Tactile methods are widely used for the measurement of surface roughness, but a destructive measurement procedure and the lack of feasibility of online monitoring are crucial drawbacks. In the last decades, several non-contact, usually optical systems for surface roughness measurements have been developed, e.g., white light interferometry, light scatter analysis, or speckle correlation. These techniques are in turn often unable to assign the roughness to a certain surface area or involve inappropriate adjustment procedures. One promising and straightforward optical measurement method is the surface roughness measurement by analyzing the fringe visibility of an interferometric fringe pattern. In our work, we employed a spatial light modulator in the interferometric setup to vary the fringe visibility and provide a stable and reliable measurement system. In previous research, either the averaged fringe visibility or the fringe visibility along a defined observation profile were analyzed. In this article, the analysis of the fringe visibility is extended to generate a complete roughness map of the measurement target. Thus, surface defects or areas of different roughness can be easily located.

Confocal laser scanning microscopy and area-scale analysis used to quantify enamel surface textural changes from citric acid demineralization and salivary remineralization in vitro.

PubMed

Austin, R S; Giusca, C L; Macaulay, G; Moazzez, R; Bartlett, D W

2016-02-01

This paper investigates the application of confocal laser scanning microscopy to determine the effect of acid-mediated erosive enamel wear on the micro-texture of polished human enamel in vitro. Twenty polished enamel samples were prepared and subjected to a citric acid erosion and pooled human saliva remineralization model. Enamel surface microhardness was measured using a Knoop hardness tester, which confirmed that an early enamel erosion lesion was formed which was then subsequently completely remineralized. A confocal laser scanning microscope was used to capture high-resolution images of the enamel surfaces undergoing demineralization and remineralization. Area-scale analysis was used to identify the optimal feature size following which the surface texture was determined using the 3D (areal) texture parameter Sa. The Sa successfully characterized the enamel erosion and remineralization for the polished enamel samples (P<0.001). Areal surface texture characterization of the surface events occurring during enamel demineralization and remineralization requires optical imaging instrumentation with lateral resolution <2.5 μm, applied in combination with appropriate filtering in order to remove unwanted waviness and roughness. These techniques will facilitate the development of novel methods for measuring early enamel erosion lesions in natural enamel surfaces in vivo. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Early postoperative changes of the foveal surface in epiretinal membranes: comparison of 23-gauge macular surgery with air vs. balanced salt solution.

PubMed

Leitritz, Martin A; Ziemssen, Focke; Voykov, Bogomil; Dimopoulos, Spyridon; Zobor, Ditta; Bartz-Schmidt, Karl U; Gelisken, Faik

2014-08-01

To analyze the foveal surface using binary image analysis after spectral-domain optical coherence tomography (SD-OCT) following 23-gauge macular surgery in epiretinal membranes (ERM) using either air tamponade (AIR) or balanced salt solution (BSS). One hundred twenty-four eyes (124 patients) with ERM that had undergone membrane peeling with installation of air or BSS were analyzed retrospectively. Ophthalmic examination was performed at baseline and 3 months. The foveal area and surface symmetry, area matched thickness, area matched contour, and best-corrected visual acuity (BCVA). The OCT images were analyzed after binary conversion with ImageJ software. Eighty eyes (80 patients) of 124 screened patients were included (AIR group: 39 patients, BSS group: 41 patients). Median follow-up time was 14 weeks (range, 9-19 weeks). Three months after surgery, the median horizontal area decreased significantly in both groups (p < 0.0001). At follow-up, the foveal surface symmetry values for the BSS group (median, 22.73 μm, range, 0-153) were significantly lower than for the AIR group (median, 23.95 μm, range, 0-160.43) (p < 0.0001). The area-matched thickness increased significantly in both groups (p < 0.001). The AIR group showed a significant increase of the area matched contour for the nasal located measurement-areas N1 (p < 0.0003), N2 (p < 0.0079), N3 (p < 0.007). The BSS group showed a significant increase of the area-matched contour for the measurement areas N1 (p < 0.019), N2 (p < 0.0014), and N4 (p < 0.022). After surgery, median BCVA for both groups increased significantly to 0.3 logMAR. The analysis of early contour changes after ERM surgery was technically possible. Long-term data have to be looked at before the clinical impact of this methodology can be estimated. Although there were no big differences between both groups (AIR vs. BSS), this could change within a longer and more representative follow-up.

Optimum BET surface areas for activated carbon produced from textile sewage sludges and its application as dye removal.

PubMed

Kacan, Erdal

2016-01-15

The purpose of this experimental study is to determine optimum preparation conditions for activated carbons obtained from textile sewage sludge (TSS) for removal of dyes from aqueous solutions. The textile sewage sludge activated carbon (TSSAC) was prepared by chemical activation with potassium hydroxide using Response Surface Methodology (RSM). The most influential factor on each experimental design responses was identified via ANNOVA analysis. Based on the central composite design (CCD), quadratic model was developed to correlate the preparation variables for one response which is the Brunauer-Emmelt-Teller (BET) surface area. RSM based on a three-variable CCD was used to determine the effect of pyrolyzed temperature (400-700 °C), carbonization time (45-180 min) and KOH: weight of TSS (wt%) impregnation ratio (0.5:1-1.5:1) on BET surface area. According to the results, pyrolyzed temperature and impregnation ratio were found as the significant factors for maximizing the BET surface area. The major effect which influences the BET surface area was found as pyrolyzed temperature. Both carbonization time and impregnation ratio of KOH had no significant effect. The optimum conditions for preparing TSSAC, based on response surface and contour plots, were found as follows: pyrolyzed temperature 700 °C, carbonization time of 45 min and chemical impregnation ratio of 0.5. The maximum and optimum BET surface area of TSSAC were found as 336 m(2)/g and 310.62 m(2)/g, respectively. Synozol Blue reactive (RSB) and Setapers Yellow-Brown (P2RFL) industrial textile dyes adsorption capacities were investigated. As expected the TSSAC which has the biggest BET surface area (336 m(2)/g) adsorbed dye best. The maximum (RSB) and (P2RFL) uptake capacities were found as 8.5383 mg/g and 5.4 mg/g, respectively. The results of this study indicated the applicability of TSSAC for removing industrial dyes from aqueous solution. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impedance analysis of PbS colloidal quantum dot solar cells with different ZnO nanowire lengths

NASA Astrophysics Data System (ADS)

Fukuda, Takeshi; Takahashi, Akihiro; Wang, Haibin; Takahira, Kazuya; Kubo, Takaya; Segawa, Hiroshi

2018-03-01

The photoconversion efficiency of colloidal quantum dot (QD) solar cells has been markedly improved by optimizing the surface passivation and device structure, and details of device physics are now under investigation. In this study, we investigated the resistance and capacitance components at the ZnO/PbS-QD interface and inside a PbS-QD layer by measuring the impedance spectrum while the interface area was controlled by changing the ZnO nanowire length. By evaluating the dependence of optical intensity and DC bias voltage on the ZnO nanowire length, only the capacitance was observed to be influenced by the interface area, and this indicates that photoinduced carriers are generated at the surface of PbS-QD. In addition, since the capacitance is proportional to the surface area of the QD, the interface area can be evaluated from the capacitance. Finally, photovoltaic performance was observed to increase with increasing ZnO nanowire length owing to the large interface area, and this result is in good agreement with the capacitance measurement.

Roles of surface water areas for water and solute cycle in Hanoi city, Viet Nam

NASA Astrophysics Data System (ADS)

Hayashi, Takeshi; Kuroda, Keisuke; Do Thuan, An; Tran Thi Viet, Nga; Takizawa, Satoshi

2013-04-01

Hanoi city, the capital of Viet Nam, has developed beside the Red river. Recent rapid urbanization of this city has reduced a large number of natural water areas such as lakes, ponds and canals not only in the central area but the suburban area. Contrary, the urbanization has increased artificial water areas such as pond for fish cultivation and landscaping. On the other hand, the urbanization has induced the inflow of waste water from households and various kinds of factories to these water areas because of delay of sewerage system development. Inflow of the waste water has induced eutrophication and pollution of these water areas. Also, there is a possibility of groundwater pollution by infiltration of polluted surface water. However, the role of these water areas for water cycle and solute transport is not clarified. Therefore, this study focuses on the interaction between surface water areas and groundwater in Hanoi city to evaluate appropriate land development and groundwater resource management. We are carrying out three approaches: a) understanding of geochemical characteristics of surface water and groundwater, b) monitoring of water levels of pond and groundwater, c) sampling of soil and pond sediment. Correlation between d18O and dD of precipitation (after GNIP), the Red River (after GNIR) and the water samples of this study showed that the groundwater is composed of precipitation, the Red River and surface water that has evaporation process. Contribution of the surface water with evaporation process was widely found in the study area. As for groundwater monitoring, the Holocene aquifers at two sites were in unconfined condition in dry season and the groundwater levels in the aquifer continued to increase through rainy season. The results of isotopic analysis and groundwater level monitoring showed that the surface water areas are one of the major groundwater sources. On the other hand, concentrations of dissolved Arsenic (filtered by 0.45um) in the pore water of the pond sediments were much higher than the pond water and closed to that of groundwater. Also, other metal elements showed the same trend. This result suggested that Arsenic and other metal elements recharged to these ponds is probably adsorbed and removed by sediments (including organic matters). That is, pond sediment plays an important role for solute transport as a filter of Arsenic and metal elements. The results of this study strongly suggest that the natural and artificial surface water areas have important roles for water cycle and solute transport in Hanoi city. Although the number of the natural water areas is decreasing, dredging of artificial water areas increases the infiltration from the surface to aquifers. Therefore, qualitative and quantitative preservation of the surface water areas is important for conservation of groundwater environment and contribute to sustainable groundwater management in Hanoi city.

The Sensitivity of Tropical Squall Lines (GATE and TOGA COARE) to Surface Fluxes: Cloud Resolving Model Simulations

NASA Technical Reports Server (NTRS)

Wang, Yansen; Tao, Wei-Kuo; Simpson, Joanne; Lang, Stephen

1999-01-01

Two tropical squall lines from TOGA COARE and GATE were simulated using a two-dimensional cloud-resolving model to examine the impact of surface fluxes on tropical squall line development and associated precipitation processes. The important question of how CAPE in clear and cloudy areas is maintained in the tropics is also investigated. Although the cloud structure and precipitation intensity are different between the TOGA COARE and GATE squall line cases, the effects of the surface fluxes on the amount of rainfall and on the cloud development processes are quite similar. The simulated total surface rainfall amount in the runs without surface fluxes is about 67% of the rainfall simulated with surface fluxes. The area where surface fluxes originated was categorized into clear and cloudy regions according to whether there was cloud in the vertical column. The model results indicated that the surface fluxes from the large clear air environment are the dominant moisture source for tropical squall line development even though the surface fluxes in the cloud region display a large peak. The high-energy air from the boundary layer in the clear area is what feeds the convection while the CAPE is removed by the convection. The surface rainfall was only reduced 8 to 9% percent in the simulations without surface fluxes in the cloud region. Trajectory and water budget analysis also indicated that most moisture (92%) was from the boundary layer of the clear air environment.

Rapid culture-independent microbial analysis aboard the International Space Station (ISS).

PubMed

Maule, Jake; Wainwright, Norm; Steele, Andrew; Monaco, Lisa; Morris, Heather; Gunter, Daniel; Damon, Michael; Wells, Mark

2009-10-01

A new culture-independent system for microbial monitoring, called the Lab-On-a-Chip Application Development Portable Test System (LOCAD-PTS), was operated aboard the International Space Station (ISS). LOCAD-PTS was launched to the ISS aboard Space Shuttle STS-116 on December 9, 2006, and has since been used by ISS crews to monitor endotoxin on cabin surfaces. Quantitative analysis was performed within 15 minutes, and sample return to Earth was not required. Endotoxin (a marker of Gram-negative bacteria) was distributed throughout the ISS, despite previous indications that mostbacteria on ISS surfaces were Gram-positive [corrected].Endotoxin was detected at 24 out of 42 surface areas tested and at every surface site where colony-forming units (cfu) were observed, even at levels of 4-120 bacterial cfu per 100 cm(2), which is below NASA in-flight requirements (<10,000 bacterial cfu per 100 cm(2)). Absent to low levels of endotoxin (<0.24 to 1.0 EU per 100 cm(2); defined in endotoxin units, or EU) were found on 31 surface areas, including on most panels in Node 1 and the US Lab. High to moderate levels (1.01 to 14.7 EU per 100 cm(2)) were found on 11 surface areas, including at exercise, hygiene, sleeping, and dining facilities. Endotoxin was absent from airlock surfaces, except the Extravehicular Hatch Handle (>3.78 EU per 100 cm(2)). Based upon data collected from the ISS so far, new culture-independent requirements (defined in EU) are suggested, which are verifiable in flight with LOCAD-PTS yet high enough to avoid false alarms. The suggested requirements are intended to supplement current ISS requirements (defined in cfu) and would serve a dual purpose of safeguarding crew health (internal spacecraft surfaces <20 EU per 100 cm(2)) and monitoring forward contamination during Constellation missions (surfaces periodically exposed to the external environment, including the airlock and space suits, <0.24 EU per 100 cm(2)).

Rapid Culture-Independent Microbial Analysis Aboard the International Space Station (ISS)

NASA Astrophysics Data System (ADS)

Maule, Jake; Wainwright, Norm; Steele, Andrew; Monaco, Lisa; Morris, Heather; Gunter, Daniel; Damon, Michael; Wells, Mark

2009-10-01

A new culture-independent system for microbial monitoring, called the Lab-On-a-Chip Application Development Portable Test System (LOCAD-PTS), was operated aboard the International Space Station (ISS). LOCAD-PTS was launched to the ISS aboard Space Shuttle STS-116 on December 9, 2006, and has since been used by ISS crews to monitor endotoxin on cabin surfaces. Quantitative analysis was performed within 15 minutes, and sample return to Earth was not required. Endotoxin (a marker of Gram-negative bacteria and fungi) was distributed throughout the ISS, despite previous indications that most bacteria on ISS surfaces were Gram-positive. Endotoxin was detected at 24 out of 42 surface areas tested and at every surface site where colony-forming units (cfu) were observed, even at levels of 4-120 bacterial cfu per 100 cm2, which is below NASA in-flight requirements (<10,000 bacterial cfu per 100 cm2). Absent to low levels of endotoxin (<0.24 to 1.0 EU per 100 cm2; defined in endotoxin units, or EU) were found on 31 surface areas, including on most panels in Node 1 and the US Lab. High to moderate levels (1.01 to 14.7 EU per 100 cm2) were found on 11 surface areas, including at exercise, hygiene, sleeping, and dining facilities. Endotoxin was absent from airlock surfaces, except the Extravehicular Hatch Handle (>3.78 EU per 100 cm2). Based upon data collected from the ISS so far, new culture-independent requirements (defined in EU) are suggested, which are verifiable in flight with LOCAD-PTS yet high enough to avoid false alarms. The suggested requirements are intended to supplement current ISS requirements (defined in cfu) and would serve a dual purpose of safeguarding crew health (internal spacecraft surfaces <20 EU per 100 cm2) and monitoring forward contamination during Constellation missions (surfaces periodically exposed to the external environment, including the airlock and space suits, <0.24 EU per 100 cm2).

Influence of snow cover changes on surface radiation and heat balance based on the WRF model

NASA Astrophysics Data System (ADS)

Yu, Lingxue; Liu, Tingxiang; Bu, Kun; Yang, Jiuchun; Chang, Liping; Zhang, Shuwen

2017-10-01

The snow cover extent in mid-high latitude areas of the Northern Hemisphere has significantly declined corresponding to the global warming, especially since the 1970s. Snow-climate feedbacks play a critical role in regulating the global radiation balance and influencing surface heat flux exchange. However, the degree to which snow cover changes affect the radiation budget and energy balance on a regional scale and the difference between snow-climate and land use/cover change (LUCC)-climate feedbacks have been rarely studied. In this paper, we selected Heilongjiang Basin, where the snow cover has changed obviously, as our study area and used the WRF model to simulate the influences of snow cover changes on the surface radiation budget and heat balance. In the scenario simulation, the localized surface parameter data improved the accuracy by 10 % compared with the control group. The spatial and temporal analysis of the surface variables showed that the net surface radiation, sensible heat flux, Bowen ratio, temperature and percentage of snow cover were negatively correlated and that the ground heat flux and latent heat flux were positively correlated with the percentage of snow cover. The spatial analysis also showed that a significant relationship existed between the surface variables and land cover types, which was not obviously as that for snow cover changes. Finally, six typical study areas were selected to quantitatively analyse the influence of land cover types beneath the snow cover on heat absorption and transfer, which showed that when the land was snow covered, the conversion of forest to farmland can dramatically influence the net radiation and other surface variables, whereas the snow-free land showed significantly reduced influence. Furthermore, compared with typical land cover changes, e.g., the conversion of forest into farmland, the influence of snow cover changes on net radiation and sensible heat flux were 60 % higher than that of land cover changes, indicating the importance of snow cover changes in the surface-atmospheric feedback system.

Electrochemical characterisation and anodic stripping voltammetry at mesoporous platinum rotating disc electrodes.

PubMed

Lozano-Sanchez, Pablo; Elliott, Joanne M

2008-02-01

Using the technique of liquid crystal templating a rotating disc electrode (RDE) was modified with a high surface area mesoporous platinum film. The surface area of the electrode was characterised by acid voltammetry, and found to be very high (ca. 86 cm(2)). Acid characterisation of the electrode produced distorted voltammograms was interpreted as being due to the extremely large surface area which produced a combination of effects such as localised pH change within the pore environment and also ohmic drop effects. Acid voltammetry in the presence of two different types of surfactant, namely Tween 20 and Triton X-100, suggested antifouling properties associated with the mesoporous deposit. Further analysis of the modified electrode using a redox couple in solution showed typical RDE behaviour although extra capacitive currents were observed due to the large surface area of the electrode. The phenomenon of underpotential deposition was exploited for the purpose of anodic stripping voltammetry and results were compared with data collected for microelectrodes. Underpotential deposition of metal ions at the mesoporous RDE was found to be similar to that at conventional platinum electrodes and mesoporous microelectrodes although the rate of surface coverage was found to be slower at a mesoporous RDE. It was found that a mesoporous RDE forms a suitable system for quantification of silver ions in solution.

Imaging and chemical surface analysis of biomolecular functionalization of monolithically integrated on silicon Mach-Zehnder interferometric immunosensors

NASA Astrophysics Data System (ADS)

Gajos, Katarzyna; Angelopoulou, Michailia; Petrou, Panagiota; Awsiuk, Kamil; Kakabakos, Sotirios; Haasnoot, Willem; Bernasik, Andrzej; Rysz, Jakub; Marzec, Mateusz M.; Misiakos, Konstantinos; Raptis, Ioannis; Budkowski, Andrzej

2016-11-01

Time-of-flight secondary ion mass spectrometry (imaging, micro-analysis) has been employed to evaluate biofunctionalization of the sensing arm areas of Mach-Zehnder interferometers monolithically integrated on silicon chips for the immunochemical (competitive) detection of bovine κ-casein in goat milk. Biosensor surfaces are examined after: modification with (3-aminopropyl)triethoxysilane, application of multiple overlapping spots of κ-casein solutions, blocking with 100-times diluted goat milk, and reaction with monoclonal mouse anti-κ-casein antibodies in blocking solution. The areas spotted with κ-casein solutions of different concentrations are examined and optimum concentration providing homogeneous coverage is determined. Coverage of biosensor surfaces with biomolecules after each of the sequential steps employed in immunodetection is also evaluated with TOF-SIMS, supplemented by Atomic force microscopy and X-ray photoelectron spectroscopy. Uniform molecular distributions are observed on the sensing arm areas after spotting with optimum κ-casein concentration, blocking and immunoreaction. The corresponding biomolecular compositions are determined with a Principal Component Analysis that distinguished between protein amino acids and milk glycerides, as well as between amino acids characteristic for Mabs and κ-casein, respectively. Use of the optimum conditions (κ-casein concentration) for functionalization of chips with arrays of ten Mach-Zehnder interferometers provided on-chips assays with dramatically improved both intra-chip response repeatability and assay detection sensitivity.

Vitrification and xenografting of human ovarian tissue.

PubMed

Amorim, Christiani Andrade; Dolmans, Marie-Madeleine; David, Anu; Jaeger, Jonathan; Vanacker, Julie; Camboni, Alessandra; Donnez, Jacques; Van Langendonckt, Anne

2012-11-01

To assess the efficiency of two vitrification protocols to cryopreserve human preantral follicles with the use of a xenografting model. Pilot study. Gynecology research unit in a university hospital. Ovarian biopsies were obtained from seven women aged 30-41 years. Ovarian tissue fragments were subjected to one of three cryopreservation protocols (slow freezing, vitrification protocol 1, and vitrification protocol 2) and xenografted for 1 week to nude mice. The number of morphologically normal follicles after cryopreservation and grafting and fibrotic surface area were determined by histologic analysis. Apoptosis was assessed by the TUNEL method. Morphometric analysis of TUNEL-positive surface area also was performed. Follicle proliferation was evaluated by immunohistochemistry. After xenografting, a difference was observed between the cryopreservation procedures applied. According to TUNEL analysis, both vitrification protocols showed better preservation of preantral follicles than the conventional freezing method. Moreover, histologic evaluation showed a significantly higher proportion of primordial follicles in vitrified (protocol 2)-warmed ovarian tissue than in frozen-thawed tissue. The proportion of growing follicles and fibrotic surface area was similar in all groups. Vitrification procedures appeared to preserve not only the morphology and survival of preantral follicles after 1 week of xenografting, but also their ability to resume folliculogenesis. In addition, vitrification protocol 2 had a positive impact on the quiescent state of primordial follicles after xenografting. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

A visiting scientist program in atmospheric sciences for the Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Davis, M. H.

1989-01-01

A visiting scientist program was conducted in the atmospheric sciences and related areas at the Goddard Laboratory for Atmospheres. Research was performed in mathematical analysis as applied to computer modeling of the atmospheres; development of atmospheric modeling programs; analysis of remotely sensed atmospheric, surface, and oceanic data and its incorporation into atmospheric models; development of advanced remote sensing instrumentation; and related research areas. The specific research efforts are detailed by tasks.

Analysis of airborne MAIS imaging spectrometric data for mineral exploration

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

Wang Jinnian; Zheng Lanfen; Tong Qingxi

1996-11-01

The high spectral resolution imaging spectrometric system made quantitative analysis and mapping of surface composition possible. The key issue will be the quantitative approach for analysis of surface parameters for imaging spectrometer data. This paper describes the methods and the stages of quantitative analysis. (1) Extracting surface reflectance from imaging spectrometer image. Lab. and inflight field measurements are conducted for calibration of imaging spectrometer data, and the atmospheric correction has also been used to obtain ground reflectance by using empirical line method and radiation transfer modeling. (2) Determining quantitative relationship between absorption band parameters from the imaging spectrometer data andmore » chemical composition of minerals. (3) Spectral comparison between the spectra of spectral library and the spectra derived from the imagery. The wavelet analysis-based spectrum-matching techniques for quantitative analysis of imaging spectrometer data has beer, developed. Airborne MAIS imaging spectrometer data were used for analysis and the analysis results have been applied to the mineral and petroleum exploration in Tarim Basin area china. 8 refs., 8 figs.« less

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.

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.

Mapping of explosive contamination using GC/chemiluminescence and ion mobility spectrometry techniques

NASA Astrophysics Data System (ADS)

Miller, Carla J.; Glenn, D. F.; Hartenstein, Steven D.; Hallowell, Susan F.

1998-12-01

Recent efforts at the Idaho National Engineering and Environmental Laboratory (INEEL) have included mapping explosive contamination resulting from manufacturing and carrying improvised explosive devices (IEDs). Two types of trace detection equipment were used to determine levels of contamination from designated sampling areas. A total of twenty IEDs were constructed: ten using TNT and ten using C-4. Two test scenarios were used. The first scenario tracked the activities of a manufacturer who straps the device onto an independent courier. The courier then performed a series of activities to simulate waiting in an airport. The second scenario tracked the activities of a manufacturer who also served as the courier. A sample set for each test consisted of thirty samples from various locations on each IED manufacturer, thirty from each IED courier, twenty-five from the manufacturing area, and twenty-five from the courier area. Pre-samples and post-samples were collected for analysis with each detection technique. Samples analyzed by gc/chemiluminescence were taken by swiping a teflon- coated sampling swipe across the surface of the sampling area to pick up any explosive particles. Samples analyzed by ion mobility spectrometry (IMS) were taken from the clothing of the manufacturer and courier by vacuuming the surface and collecting particulates on a fiberglass filter. Samples for IMS analysis from the manufacturing and courier rooms were taken by wiping a cotton sampling swipe across the surface area. Currently, building IEDs and monitoring the explosive contamination is being directed toward detection with portal monitors.

Spatially distributed rockfall activity inferred from talus deposits and corresponding rockwall areas in the Gradenbach catchment (Schober Mountains, Austria)

NASA Astrophysics Data System (ADS)

Götz, Joachim; Buckel, Johannes; Heckmann, Tobias

2013-04-01

The analysis of alpine sediment cascades requires the identification, differentiation and quantification of sediment sources, storages, and transport processes. This study deals with the origin of alpine sediment transfer and relates primary talus deposits to corresponding rockwall source areas within the Gradenbach catchment (Schober Mountains, Austrian Alps). Sediment storage landforms are based on a detailed geomorphological map of the catchment which was generated to analyse the sediment transfer system. Mapping was mainly performed in the field and supplemented by post-mapping analysis using LIDAR data and digital orthophotos. A fundamental part of the mapping procedure was to capture additional landform-based information with respect to morphometry, activity and connectivity. The applied procedure provides a detailed inventory of sediment storage landforms including additional information on surface characteristics, dominant and secondary erosion and deposition processes, process activity and sediment storage coupling. We develop the working hypothesis that the present-day surface area ratio between rockfall talus (area as a proxy for volume, backed by geophysical analysis of selected talus cones) and corresponding rockwall source area is a measure of rockfall activity since deglaciation; large talus cones derived from small rockwall catchments indicate high activity, while low activity can be inferred where rockfall from large rock faces has created only small deposits. The surface area ratio of talus and corresponding rockwalls is analysed using a landform-based and a process-based approach. For the landform-based approach, we designed a GIS procedure which derives the (hydrological) catchment area of the contact lines of talus and rockwall landforms in the geomorphological map. The process-based approach simulates rockfall trajectories from steep (>45°) portions of a DEM generated by a random-walk rockfall model. By back-tracing those trajectories that end on a selected talus landform, the 'rockfall contributing area' is delineated; this approach takes account of the stochastic nature of rockfall trajectories and is able to identify, for example, rockfall delivery from one rockwall segment to multiple talus landforms (or from multiple rockfall segments to the same deposit, respectively). Using both approaches, a total of 290 rockwall-talus-subsystems are statistically analysed indicating a constant relationship between rockfall source areas and corresponding areas of talus deposits of almost 1:1. However, certain rockwall-talus-subsystems deviate from this correlation since sediment storage landforms of similar size originate from varying rockwall source areas and vice versa. This varying relationship is assumed to be strongly controlled by morphometric parameters, such as rockwall slope, altitudinal interval, and aspect. The impact of these parameters on the surface area ratio will be finally discussed.

Medium Caliber Lead-Free Electric Primer. Version 2

DTIC Science & Technology

2012-09-01

Toxic Substance Control Act TGA Thermogravimetric Analysis TNR Trinitroresorcinol V Voltage VDC Voltage Direct Current WSESRB Weapons System...variety of techniques including Thermogravimetric Analysis (TGA), base-hydrolysis, Surface Area Analysis using Brunauer, Emmett, Teller (BET...Distribution From Thermogravimetric Analysis Johnson, C. E.; Fallis, S.; Chafin, A. P.; Groshens, T. J.; Higa, K. T.; Ismail, I. M. K. and Hawkins, T. W

Deformation mechanics of deep surface flaw cracks

NASA Technical Reports Server (NTRS)

Francis, P. H.; Nagy, A.; Beissner, R. E.

1972-01-01

A combined analytical and experimental program was conducted to determine the deformation characteristics of deep surface cracks in Mode I loading. An approximate plane finite element analysis was performed to make a parameter study on the influence of crack depth, crack geometry, and stress level on plastic zones, crack opening displacement, and back surface dimpling in Fe-3Si steel and 2219-T87 aluminum. Surface replication and profiling techniques were used to examine back surface dimple configurations in 2219-T87 aluminum. Interferometry and holography were used to evaluate the potential of various optical techniques to detect small surface dimples on large surface areas.

Differential processing of binocular and monocular gloss cues in human visual cortex

PubMed Central

Di Luca, Massimiliano; Ban, Hiroshi; Muryy, Alexander; Fleming, Roland W.

2016-01-01

The visual impression of an object's surface reflectance (“gloss”) relies on a range of visual cues, both monocular and binocular. Whereas previous imaging work has identified processing within ventral visual areas as important for monocular cues, little is known about cortical areas involved in processing binocular cues. Here, we used human functional MRI (fMRI) to test for brain areas selectively involved in the processing of binocular cues. We manipulated stereoscopic information to create four conditions that differed in their disparity structure and in the impression of surface gloss that they evoked. We performed multivoxel pattern analysis to find areas whose fMRI responses allow classes of stimuli to be distinguished based on their depth structure vs. material appearance. We show that higher dorsal areas play a role in processing binocular gloss information, in addition to known ventral areas involved in material processing, with ventral area lateral occipital responding to both object shape and surface material properties. Moreover, we tested for similarities between the representation of gloss from binocular cues and monocular cues. Specifically, we tested for transfer in the decoding performance of an algorithm trained on glossy vs. matte objects defined by either binocular or by monocular cues. We found transfer effects from monocular to binocular cues in dorsal visual area V3B/kinetic occipital (KO), suggesting a shared representation of the two cues in this area. These results indicate the involvement of mid- to high-level visual circuitry in the estimation of surface material properties, with V3B/KO potentially playing a role in integrating monocular and binocular cues. PMID:26912596

Analysis of Loss of Ignition of Root Zone of Bioretention Units at the Edison Environmental Center

EPA Science Inventory

Six bioretention units (widths 7.1 m) at USEPA’s Edison Environmental Center were constructed to evaluate sizing of surface area to watershed area. Three sizes were tested in duplicate with changes in aspect ratio of length from inlet (northern) wall by doubling successive ...

White Sands Missile Range Main Cantonment and NASA Area Faults, New Mexico

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

Nash, Greg

This is a zipped ArcGIS shapefile containing faults mapped for the Tularosa Basin geothermal play fairway analysis project. The faults were interpolated from gravity and seismic (NASA area) data, and from geomorphic features on aerial photography. Field work was also done for validation of faults which had surface expressions.

Preliminary Water-Table Map and Water-Quality Data for Part of the Matanuska-Susitna Valley, Alaska, 2005

USGS Publications Warehouse

Moran, Edward H.; Solin, Gary L.

2006-01-01

The Matanuska-Susitna Valley is in the northeastern part of the Cook Inlet Basin, Alaska, an area experiencing rapid population growth and development proximal to many lakes. Here water commonly flows between lakes and ground water, indicating interrelation between water quantity and quality. Thus concerns exist that poorer quality ground water may degrade local lake ecosystems. This concern has led to water-quality sampling in cooperation with the Alaska Department of Environmental Conservation and the Matanuska-Susitna Borough. A map showing the estimated altitude of the water table illustrates potential ground-water flow directions and areas where ground- and surface-water exchanges and interactions might occur. Water quality measured in selected wells and lakes indicates some differences between ground water and surface water. 'The temporal and spatial scarcity of ground-water-level and water-quality data limits the analysis of flow direction and water quality. Regionally, the water-table map indicates that ground water in the eastern and southern parts of the study area flows southerly. In the northcentral area, ground water flows predominately westerly then southerly. Although ground and surface water in most areas of the Matanuska-Susitna Valley are interconnected, they are chemically different. Analyses of the few water-quality samples collected in the area indicate that dissolved nitrite plus nitrate and orthophosphorus concentrations are higher in ground water than in surface water.'

Integration of remote sensing based surface information into a three-dimensional microclimate model

NASA Astrophysics Data System (ADS)

Heldens, Wieke; Heiden, Uta; Esch, Thomas; Mueller, Andreas; Dech, Stefan

2017-03-01

Climate change urges cities to consider the urban climate as part of sustainable planning. Urban microclimate models can provide knowledge on the climate at building block level. However, very detailed information on the area of interest is required. Most microclimate studies therefore make use of assumptions and generalizations to describe the model area. Remote sensing data with area wide coverage provides a means to derive many parameters at the detailed spatial and thematic scale required by urban climate models. This study shows how microclimate simulations for a series of real world urban areas can be supported by using remote sensing data. In an automated process, surface materials, albedo, LAI/LAD and object height have been derived and integrated into the urban microclimate model ENVI-met. Multiple microclimate simulations have been carried out both with the dynamic remote sensing based input data as well as with manual and static input data to analyze the impact of the RS-based surface information and the suitability of the applied data and techniques. A valuable support of the integration of the remote sensing based input data for ENVI-met is the use of an automated processing chain. This saves tedious manual editing and allows for fast and area wide generation of simulation areas. The analysis of the different modes shows the importance of high quality height data, detailed surface material information and albedo.

Trends in surface ozone over Europe, 1978-1990

NASA Technical Reports Server (NTRS)

Low, Pak Sum; Kelly, P. Michael; Davies, Trevor D.

1994-01-01

It has been suggested that surface ozone concentrations in rural areas of Europe have been increasing at a rate of 1 to 3 percent per year over the past two to three decades, presumably due to human influences (Feister and Warmbt, 1987; Bojkov, 1988; Penkett, 1989). Recently, we have analyzed surface ozone data from 20 European stations of differing character (remote, rural, suburban and urban) for a common period of 1978-1988 (Low et al., 1992). It was found that there were pronounced annual and seasonal variations in the linear trends in different areas, and there was no dominant region-wide trend. In spring and, most notably, summer, stations on the maritime fringe of the network generally exhibited negative trends whilst those located further into the continental interior exhibited positive trends. In winter, most of the stations in the network exhibited positive trends. Relatively few of these trends were statistically significant. This paper updates our earlier analysis by extending the data sets of the network up to the year 1990. The spatial variations in surface ozone trends over the extended period 1978-1990 are examined and discussed in comparison to the 1978-1988 patterns. The update confirms the overall conclusions of the earlier analysis, specifically that caution should be exercised in interpreting the results of trend analyses based on station data representative of a limited period of time and/or geographical area.

Histochemical changes of occlusal surface enamel of permanent teeth, where dental caries is questionable vs sound enamel surfaces.

PubMed

Michalaki, M; Oulis, C J; Pandis, N; Eliades, G

2016-12-01

This in vitro study was to classify questionable for caries occlusal surfaces (QCOS) of permanent teeth according to ICDAS codes 1, 2, and 3 and to compare them in terms of enamel mineral composition with the areas of sound tissue of the same tooth. Partially impacted human molars (60) extracted for therapeutic reasons with QCOS were used in the study, photographed via a polarised light microscope and classified according to the ICDAS II (into codes 1, 2, or 3). The crowns were embedded in clear self-cured acrylic resin and longitudinally sectioned at the levels of the characterised lesions and studied by SEM/EDX, to assess enamel mineral composition of the QCOS. Univariate and multivariate random effect regressions were used for Ca (wt%), P (wt%), and Ca/P (wt%). The EDX analysis indicated changes in the Ca and P contents that were more prominent in ICDAS-II code 3 lesions compared to codes 1 and 2 lesions. In these lesions, Ca (wt%) and P (wt%) concentrations were significantly decreased (p = 0.01) in comparison with sound areas. Ca and P (wt%) contents were significantly lower (p = 0.02 and p = 0.01 respectively) for code 3 areas in comparison with codes 1 and 2 areas. Significantly higher (p = 0.01) Ca (wt%) and P (wt%) contents were found on sound areas compared to the lesion areas. The enamel of occlusal surfaces of permanent teeth with ICDAS 1, 2, and 3 lesions was found to have different Ca/P compositions, necessitating further investigation on whether these altered surfaces might behave differently on etching preparation before fissure sealant placement, compared to sound surfaces.

Solvothermal synthesis of hierarchical TiO2 nanostructures with tunable morphology and enhanced photocatalytic activity

NASA Astrophysics Data System (ADS)

Fan, Zhenghua; Meng, Fanming; Zhang, Miao; Wu, Zhenyu; Sun, Zhaoqi; Li, Aixia

2016-01-01

This paper presents controllable growth and photocatalytic activity of TiO2 hierarchical nanostructures by solvothermal method at different temperatures. It is revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that the morphology of TiO2 can be effectively controlled as rose-like, chrysanthemum-like and sea-urchin-like only changing solvothermal temperature. BET surface area analysis confirms the presence of a mesoporous network in all the nanostructures, and shows high surface area at relatively high temperature. The photocatalytic activities of the photocatalysts are evaluated by the photodegradation of RhB under UV light irradiation. The TiO2 samples exhibit high activity on the photodegradation of RhB, which is higher than that of the commercial P25. The enhancement in photocatalytic performance can be attributed to the synergetic effect of the surface area, crystallinity, band gap and crystalline size.

Quantitative analysis of the extensional tectonics of Tharsis bulge, Mars - Geodynamic implications

NASA Astrophysics Data System (ADS)

Thomas, P. G.; Allemand, P.

1993-07-01

The amount of horizontal strain on the Martian Tharsis bulge is quantified in order to provide further information on the tectonic evolution of this province. About 10 percent of the Tharsis surface bulge exhibits elliptical impact craters, which are the largest strain markers in the solar system. It is shown that these strain ellipses indicate more strain than could be due to the bulge building alone. The existence of such intensely deformed areas, the direction of the extensive strain, the localization of these areas on the bulge crest or on the top of topographic slopes, and the evidence of nonthinned crust under these areas may all be explained by gravitational slidings of the bulge surface over the topographic slope. This sliding would be possible because of the presence of a decollement level two kilometers below the surface, and because of the prefracturation which have made the detachment possible.

Effect of SrO content on Zeolite Structure

NASA Astrophysics Data System (ADS)

Widiarti, N.; Sari, U. S.; Mahatmanti, F. W.; Harjito; Kurniawan, C.; Prasetyoko, D.; Suprapto

2018-04-01

The aims of current studies is to investigate the effect of strontium oxide content (SrO) on synthesized zeolite. Zeolite was synthesized from Tetraethyl orthosilicate (TEOS) as precursors of SiO2 and aluminum isopropoxide (AIP) precursors. The mixture was aged for 3 days and hydrothermally treated for 6 days. The SrO content was added by impregnation method. The products were then characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), and Surface Area Analyzer (SAA). The diffractogram confirmed the formation of Faujasite-like zeolite. However, after the addition of SrO, the crystallinity of zeolite was deformed. The diffractograms shows the amorphous phase of zeolite were decrease as the SrO content is increase. The structural changes was also observed from FTIR spectra which shows the shifting and peak formation. The surface area analysis showed that the increasing loading of SrO/Zeolites reduced the catalyst surface area.

Study on temporal and spatial variations of urban land use based on land change data

NASA Astrophysics Data System (ADS)

Jiang, Ping; Liu, Yanfang; Fan, Min; Zhang, Yang

2009-10-01

With the rapid development of urbanization, demands of urban land increase in succession, hence, to analyze temporal and spatial variations of urban land use becomes more and more important. In this paper, the principle of trend surface analysis and formula of urban land sprawl index ( ULSI) are expatiated at first, and then based on land change data of Jiayu county, the author fits quadratic trend surface by choosing urban land area as dependent variable and urbanization and GDP as independent variables from 1996 to 2006, draws isoline of trend surface and residual values; and then urban land sprawl indexes of towns are calculated on the basis of urban land area of 1996 and 2006 and distribution map of ULSI is plotted. After analyzing those results, we can conclude that there is consanguineous relationship between urban land area and urbanization, economic level etc.

On the formation of nanocrystalline active zinc oxide from zinc hydroxide carbonate

NASA Astrophysics Data System (ADS)

Moezzi, Amir; Cortie, Michael; Dowd, Annette; McDonagh, Andrew

2014-04-01

The decomposition of zinc hydroxide carbonate, Zn5(CO3)2(OH)6 (ZHC), into the high surface area form of ZnO known as "active zinc oxide" is examined. In particular, the nucleation and evolution of the ZnO nanocrystals is of interest as the size of these particles controls the activity of the product. The decomposition process was studied using X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy and BET surface area measurements. At about 240 °C ZHC decomposes to porous ZnO in a single step. The product material has a specific surface area in the range of 47-65 m2 g-1 and initially has a crystallite size that is of the order of 10 nm. A further increase in temperature, however, causes the particles to coarsen to over 25 nm in diameter. In principle, the coarsening phenomenon may be interrupted to control the particle size.

Impedance spectroscopy study on graphene wrapped nanocrystalline V{sub 2}O{sub 5}

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

Bhaskaram, D. Surya, E-mail: dsurya.b@gmail.com; Govindaraj, G.; Cheruku, Rajesh

2016-05-23

Nanocrystalline V{sub 2}O{sub 5} was synthesized by solvothermal technique, which has potential application as electrode material in supercapacitors. The graphene oxide (GO) was prepared by modified Hummer’s method. The V{sub 2}O{sub 5}/ reduced graphene oxide (RGO) composite was synthesized using surfactant free hydrothermal technique to enhance the functionality in terms of conductivity and surface area of V{sub 2}O{sub 5}. The structural characterization was accomplished through X-ray diffraction and Raman spectroscopy. Morphology was identified by SEM and surface area of VRGO was enhanced by 8 times in comparison with V{sub 2}O{sub 5} nano particles, as confirmed through BET surface area analysis.more » Electrical characterization was done through impedance spectroscopy and the results showed decrease in sample resistance after wrapping V{sub 2}O{sub 5} with RGO.« less

Navy Tactical Applications Guide, Volume 8 Part 2: Arctic - East Siberian/Chukchi/Beaufort Seas. Weather Analysis and Forecast Applications

DTIC Science & Technology

1992-12-01

storm. The southernmost vortex does not appear as a closed circulation in the surface analysis (Fig. lA-9b) whereas the central Alaskan vortex seems...rise to an enhanced cloud trail. lA-40 FNOC surface analysis . 27 January 1989, 0600 GMT. lA-40 / /■■■■ / / ’’ / I ’:/, d m ,MeSOSCALE VORTEX AND...emphasized to clarify that this is a different system than the cloud vortex we have been describing, yet is close to the same area. A careful assessment of

Fracture surface analysis of a quenched (α+β)-metastable titanium alloy

NASA Astrophysics Data System (ADS)

Illarionov, A. G.; Stepanov, S. I.; Demakov, S. L.

2017-12-01

Fracture surface analysis is conducted by means of SEM for VT16 titanium alloy specimens solution-treated at temperatures ranging from 700 to 875 °C, water-quenched and subjected to tensile testing. A cup and cone shape failure and dimple microstructure of the fracture surface indicates the ductile behavior of the alloy. Dimple dimensions correlated with the β-grain size of the alloy in quenched condition. The fracture area (namely, the size; the cup and cone shape) depends on the volume fraction of the primary α-phase in the quenched sample. However, the fracture surface changes considerably when the strain-induced β-αʺ-transformation takes place during tensile testing, resulting in the increase of alloy ductility.

Is the planum temporale surface area a marker of hemispheric or regional language lateralization?

PubMed

Tzourio-Mazoyer, Nathalie; Crivello, Fabrice; Mazoyer, Bernard

2018-04-01

We investigated the association between the left planum temporale (PT) surface area or asymmetry and the hemispheric or regional functional asymmetries during language production and perception tasks in 287 healthy adults (BIL&GIN) who were matched for sex and handedness. The measurements of the PT surface area were performed after manually delineating the region using brain magnetic resonance images (MRI) and considering the Heschl's gyrus (HG) duplication pattern; the measurements either included (PT tot ) or did not include (PT post ) the second gyrus. A region encompassing both the PT and HG (HGPT) was also studied. Regardless of the ROI measured, 80% of the sample had a positive left minus right PT asymmetry. We first tested whether the PT tot , PT post and HGPT surface areas in the left or right hemispheres or PT asymmetries differed in groups of individuals varying in language lateralization by assessing their hemispheric index during a sentence production minus word list production task. We then investigated the association between these different measures of the PT anatomy and the regional asymmetries measured during the task. Regardless of the anatomical definition used, we observed no correlations between the left surface areas or asymmetries and the hemispheric or regional functional asymmetries during the language production task. We then performed a similar analysis using the same sample measuring language functional lateralization during speech listening tasks (i.e., listening to sentences and lists of words). Although the hemispheric lateralization during speech listening was not correlated with the left PT tot , PT post or HGPT surface areas or the PT asymmetries, significant positive correlations were observed between the asymmetries in these regions and the regional functional asymmetries measured in areas adjacent to the end of the Sylvian fissure while participants listened to the word lists or sentences. The PT asymmetry thus appears to be associated with the local functional asymmetries in auditory areas but is not a marker of inter-individual variability in language dominance.

Hydrological Response to Land Cover Changes and Human Activities in Arid Regions Using a Geographic Information System and Remote Sensing

PubMed Central

Mahmoud, Shereif H.; Alazba, A. A.

2015-01-01

The hydrological response to land cover changes induced by human activities in arid regions has attracted increased research interest in recent decades. The study reported herein assessed the spatial and quantitative changes in surface runoff resulting from land cover change in the Al-Baha region of Saudi Arabia between 1990 and 2000 using an ArcGIS-surface runoff model and predicted land cover and surface runoff depth in 2030 using Markov chain analysis. Land cover maps for 1990 and 2000 were derived from satellite images using ArcGIS 10.1. The findings reveal a 26% decrease in forest and shrubland area, 28% increase in irrigated cropland, 1.5% increase in sparsely vegetated land and 0.5% increase in bare soil between 1990 and 2000. Overall, land cover changes resulted in a significant decrease in runoff depth values in most of the region. The decrease in surface runoff depth ranged from 25-106 mm/year in a 7020-km2 area, whereas the increase in such depth reached only 10 mm/year in a 243-km2 area. A maximum increase of 73 mm/year was seen in a limited area. The surface runoff depth decreased to the greatest extent in the central region of the study area due to the huge transition in land cover classes associated with the construction of 25 rainwater harvesting dams. The land cover prediction revealed a greater than twofold increase in irrigated cropland during the 2000-2030 period, whereas forest and shrubland are anticipated to occupy just 225 km2 of land area by 2030, a significant decrease from the 747 km2 they occupied in 2000. Overall, changes in land cover are predicted to result in an annual increase in irrigated cropland and dramatic decline in forest area in the study area over the next few decades. The increase in surface runoff depth is likely to have significant implications for irrigation activities. PMID:25923712

An analytical framework for extracting hydrological information from time series of small reservoirs in a semi-arid region

NASA Astrophysics Data System (ADS)

Annor, Frank; van de Giesen, Nick; Bogaard, Thom; Eilander, Dirk

2013-04-01

Small water reservoirs for water resources management have as important socio-economic advantage that they bring water close to villages and households. This proximity allows for many water uses in addition to irrigation, such as fisheries, household water, building materials (loam, reeds), tourism and recreation, and cattle watering. These positive aspects are offset by the relatively large evaporative losses in comparison to larger reservoirs, although, it is not exactly known how large these losses are. For decision makers, investors and donors, the decision to construct a small reservoir should be multifactored; and based on economic, socio-cultural and environmental factors. For the latter, getting the water balance and the energy budget of small reservoirs right is key for any environmental impact analyses. For Northern Ghana, the relation between volume of a small reservoir and its' surface area has been established in a robust equation as: Volume = 0.00857Area1.4367 with the surface area explaining more than 95% of the variation in water volume of the reservoirs. This allows the use of remote sensing observations for estimating water volume of small reservoirs in northern Ghana. Hydrological analyses of time series of small reservoir areas comprises estimates of evaporation fluxes and cumulative surface runoff curves. Once the reservoirs are full, spillage will occur and volumes and surface areas remain stable at their maximum extents. This implies that the time series of reservoir surface area contains information concerning the on-set of downstream surface runoff. This on-set does not coincide with the on-set of the rainy season but largely depends on the distribution of rainfall events and storage capacity in the subsurface. The main requirement for this analysis is that the reservoir has negligible seepage losses or water influx from the underlying subsurface. In our research, we carried out a time series analysis of surface area extent for about 45 small reservoirs in the Upper East Region of Ghana. Reservoirs without obvious large seepage losses (field survey) were selected. To verify this, stable water isotopic samples are collected from groundwater upstream and downstream from the reservoir. By looking at possible enrichment of downstream groundwater, a good estimate of seepage can be made in addition to estimates on evaporation. We estimated the evaporative losses and compared those with field measurements using eddy correlation measurements. Lastly, we determined the cumulative surface runoff curves for the small reservoirs .We will present this analytical framework for extracting hydrological information from time series of small reservoirs and show the first results for our study region of northern Ghana.

Geologic Map of the Helen Planitia Quadrangle (V-52), Venus

USGS Publications Warehouse

Lopez, Ivan; Hansen, Vicki L.

2008-01-01

The Magellan spacecraft orbited Venus from August 10, 1990, until it plunged into the Venusian atmosphere on October 12, 1994. Magellan Mission objectives included (1) improving the knowledge of the geological processes, surface properties, and geologic history of Venus by analysis of surface radar characteristics, topography, and morphology and (2) improving the knowledge of the geophysics of Venus by analysis of Venusian gravity. The Helen Planitia quadrangle (V-52), located in the southern hemisphere of Venus between lat 25 deg S. and 50 deg S. and between long 240 deg E. and 270 deg E., covers approximately 8,000,000 km2. Regionally, the map area is located at the southern limit of an area of enhanced tectonomagmatic activity and extensional deformation, marked by a triangle that has highland apexes at Beta, Atla, and Themis Regiones (BAT anomaly) and is connected by the large extensional belts of Devana, Hecate, and Parga Chasmata. The BAT anomaly covers approximately 20 percent of the Venusian surface.

Aerodynamic design and analysis system for supersonic aircraft. Part 3: Computer program description

NASA Technical Reports Server (NTRS)

Middleton, W. D.; Lundry, J. L.; Coleman, R. G.

1975-01-01

The computer program for the design and analysis of supersonic aircraft configurations is presented. The schematics of the program structure are provided. The individual overlays and subroutines are described. The system is useful in determining surface pressures and supersonic area rule concepts.

Spatial variability of specific surface area of arable soils in Poland

NASA Astrophysics Data System (ADS)

Sokolowski, S.; Sokolowska, Z.; Usowicz, B.

2012-04-01

Evaluation of soil spatial variability is an important issue in agrophysics and in environmental research. Knowledge of spatial variability of physico-chemical properties enables a better understanding of several processes that take place in soils. In particular, it is well known that mineralogical, organic, as well as particle-size compositions of soils vary in a wide range. Specific surface area of soils is one of the most significant characteristics of soils. It can be not only related to the type of soil, mainly to the content of clay, but also largely determines several physical and chemical properties of soils and is often used as a controlling factor in numerous biological processes. Knowledge of the specific surface area is necessary in calculating certain basic soil characteristics, such as the dielectric permeability of soil, water retention curve, water transport in the soil, cation exchange capacity and pesticide adsorption. The aim of the present study is two-fold. First, we carry out recognition of soil total specific surface area patterns in the territory of Poland and perform the investigation of features of its spatial variability. Next, semivariograms and fractal analysis are used to characterize and compare the spatial variability of soil specific surface area in two soil horizons (A and B). Specific surface area of about 1000 samples was determined by analyzing water vapor adsorption isotherms via the BET method. The collected data of the values of specific surface area of mineral soil representatives for the territory of Poland were then used to describe its spatial variability by employing geostatistical techniques and fractal theory. Using the data calculated for some selected points within the entire territory and along selected directions, the values of semivariance were determined. The slope of the regression line of the log-log plot of semi-variance versus the distance was used to estimate the fractal dimension, D. Specific surface area in A and B horizons was space-dependent, with the range of spatial dependence of about 2.5°. Variogram surfaces showed anisotropy of the specific surface area in both horizons with a trend toward the W to E directions. The smallest fractal dimensions were obtained for W to E directions and the highest values - for S to N directions. * The work was financially supported in part by the ESA Programme for European Cooperating States (PECS), No.98084 "SWEX-R, Soil Water and Energy Exchange/Research", AO3275.

Combining Landform Thematic Layer and Object-Oriented Image Analysis to Map the Surface Features of Mountainous Flood Plain Areas

NASA Astrophysics Data System (ADS)

Chuang, H.-K.; Lin, M.-L.; Huang, W.-C.

2012-04-01

The Typhoon Morakot on August 2009 brought more than 2,000 mm of cumulative rainfall in southern Taiwan, the extreme rainfall event caused serious damage to the Kaoping River basin. The losses were mostly blamed on the landslides along sides of the river, and shifting of the watercourse even led to the failure of roads and bridges, as well as flooding and levees damage happened around the villages on flood bank and terraces. Alluvial fans resulted from debris flow of stream feeders blocked the main watercourse and debris dam was even formed and collapsed. These disasters have highlighted the importance of identification and map the watercourse alteration, surface features of flood plain area and artificial structures soon after the catastrophic typhoon event for natural hazard mitigation. Interpretation of remote sensing images is an efficient approach to acquire spatial information for vast areas, therefore making it suitable for the differentiation of terrain and objects near the vast flood plain areas in a short term. The object-oriented image analysis program (Definiens Developer 7.0) and multi-band high resolution satellite images (QuickBird, DigitalGlobe) was utilized to interpret the flood plain features from Liouguei to Baolai of the the Kaoping River basin after Typhoon Morakot. Object-oriented image interpretation is the process of using homogenized image blocks as elements instead of pixels for different shapes, textures and the mutual relationships of adjacent elements, as well as categorized conditions and rules for semi-artificial interpretation of surface features. Digital terrain models (DTM) are also employed along with the above process to produce layers with specific "landform thematic layers". These layers are especially helpful in differentiating some confusing categories in the spectrum analysis with improved accuracy, such as landslides and riverbeds, as well as terraces, riverbanks, which are of significant engineering importance in disaster mitigation. In this study, an automatic and fast image interpretation process for eight surface features including main channel, secondary channel, sandbar, flood plain, river terrace, alluvial fan, landslide, and the nearby artificial structures in the mountainous flood plain is proposed. Images along timelines can even be compared in order to differentiate historical events such as village inundations, failure of roads, bridges and levees, as well as alternation of watercourse, and therefore can be used as references for safety evaluation of engineering structures near rivers, disaster prevention and mitigation, and even future land-use planning. Keywords: Flood plain area, Remote sensing, Object-oriented, Surface feature interpretation, Terrain analysis, Thematic layer, Typhoon Morakot

Colour change evaluation on UV radiation exposure for Păun-Repedea calcareous geomaterial

NASA Astrophysics Data System (ADS)

Pelin, V.; Sandu, I.; Munteanu, M.; Iurcovschi, C. T.; Gurlui, S.; Sandu, AV; Vasilache, V.; Brȃnzilă, M.; Sandu, I. G.

2016-06-01

When talking about the preservation treatments that can be applied to natural stones used in different constructions, the surface hydrophobization plays an important part, especially when referring to porous surfaces like the calcareous oolithic stones specific to Repedea area, Iasi County, Romania. The present paper presents a method that evaluates the hydrophobization efficiency of two types of pellicles, involving UV artificial ageing and colorimetric analysis of the treated surfaces. The evaluation was done through continuous colorimetric monitoring and by comparing the evolution of the chromatic modifications of the two treated surfaces with the original colorimetric values and with the witness area, which was exposed to UV radiations under the same conditions, but left chemical untreated. The techniques used during this experiment were: CIE L*a*b* colorimetry, OM, SEM-EDX, UV radiation exposure and Spectrum Irradiance Measurement.

A Study of Land Surface Temperature Retrieval and Thermal Environment Distribution Based on Landsat-8 in Jinan City

NASA Astrophysics Data System (ADS)

Dong, Fang; Chen, Jian; Yang, Fan

2018-01-01

Based on the medium resolution Landsat 8 OLI/TIRS, the temperature distribution in four seasons of urban area in Jinan City was obtained by using atmospheric correction method for the retrieval of land surface temperature. Quantitative analysis of the spatio-temporal distribution characteristics, development trend of urban thermal environment, the seasonal variation and the relationship between surface temperature and normalized difference vegetation index (NDVI) was studied. The results show that the distribution of high temperature areas is concentrated in Jinan, and there is a tendency to expand from east to west, revealing a negative correlation between land surface temperature distribution and NDVI. So as to provide theoretical references and scientific basis of improving the ecological environment of Jinan City, strengthening scientific planning and making overall plan addressing climate change.

Micromorphological characterization of zinc/silver particle composite coatings

PubMed Central

Méndez, Alia; Reyes, Yolanda; Trejo, Gabriel; StĘpień, Krzysztof

2015-01-01

ABSTRACT The aim of this study was to evaluate the three‐dimensional (3D) surface micromorphology of zinc/silver particles (Zn/AgPs) composite coatings with antibacterial activity prepared using an electrodeposition technique. These 3D nanostructures were investigated over square areas of 5 μm × 5 μm by atomic force microscopy (AFM), fractal, and wavelet analysis. The fractal analysis of 3D surface roughness revealed that (Zn/AgPs) composite coatings have fractal geometry. Triangulation method, based on the linear interpolation type, applied for AFM data was employed in order to characterise the surfaces topographically (in amplitude, spatial distribution and pattern of surface characteristics). The surface fractal dimension D f, as well as height values distribution have been determined for the 3D nanostructure surfaces. Microsc. Res. Tech. 78:1082–1089, 2015. © 2015 The Authors published by Wiley Periodicals, Inc. PMID:26500164

Subsidence Induced Faulting Hazard Zonation Using Persistent Scatterer Interferometry and Horizontal Gradient Mapping in Mexican Urban Areas

NASA Astrophysics Data System (ADS)

Cabral-Cano, E.; Cigna, F.; Osmanoglu, B.; Dixon, T.; Wdowinski, S.

2011-12-01

Subsidence and faulting have affected Mexico city for more than a century and the process is becoming widespread throughout larger urban areas in central Mexico. This process causes substantial damages to the urban infrastructure and housing structures and will certainly become a major factor to be considered when planning urban development, land use zoning and hazard mitigation strategies in the next decades. Subsidence is usually associated with aggressive groundwater extraction rates and a general decrease of aquifer static level that promotes soil consolidation, deformation and ultimately, surface faulting. However, local stratigraphic and structural conditions also play an important role in the development and extension of faults. In all studied cases stratigraphy of the uppermost sediment strata and the structure of the underlying volcanic rocks impose a much different subsidence pattern which is most suitable for imaging through satellite geodetic techniques. We present examples from several cities in central Mexico: a) Mexico-Chalco. Very high rates of subsidence, up to 370 mm/yr are observed within this lacustrine environment surrounded by Pliocene-Quaternary volcanic structures. b) Aguascalientes where rates up to 90 mm/yr in the past decade are observed, is controlled by a stair stepped N-S trending graben that induces nucleation of faults along the edges of contrasting sediment package thicknesses. c) Morelia presents subsidence rates as high as 80 mm/yr. Differential deformation is observed across major basin-bounding E-W trending faults and with higher subsidence rates on their hanging walls, where the thickest sequences of compressible Quaternary sediments crop out. Our subsidence and faulting study in urban areas of central Mexico is based on a horizontal gradient analysis using displacement maps from Persistent Scatterer InSAR that allows definition of areas with high vulnerability to surface faulting. Correlation of the surface subsidence pattern through satellite geodesy and surface faults show that the principal factor for defining these hazardous areas is best determined not by solely using the subsidence magnitude rates but rather by using a combined magnitude and horizontal subsidence gradient analysis. This approach is used as the basis for the generation of subsidence-induced surface faulting hazard maps for the studied urban areas.

Exergy analysis of large-scale helium liquefiers: Evaluating design trade-offs

NASA Astrophysics Data System (ADS)

Thomas, Rijo Jacob; Ghosh, Parthasarathi; Chowdhury, Kanchan

2014-01-01

It is known that higher heat exchanger area, more number of expanders with higher efficiency and more involved configuration with multi-pressure compression system increase the plant efficiency of a helium liquefier. However, they involve higher capital investment and larger size. Using simulation software Aspen Hysys v 7.0 and exergy analysis as the tool of analysis, authors have attempted to identify various trade-offs while selecting the number of stages, the pressure levels in compressor, the cold-end configuration, the heat exchanger surface area, the maximum allowable pressure drop in heat exchangers, the efficiency of expanders, the parallel/series connection of expanders etc. Use of more efficient cold ends reduces the number of refrigeration stages and the size of the plant. For achieving reliability along with performance, a configuration with a combination of expander and Joule-Thomson valve is found to be a better choice for cold end. Use of multi-pressure system is relevant only when the number of refrigeration stages is more than 5. Arrangement of expanders in series reduces the number of expanders as well as the heat exchanger size with slight expense of plant efficiency. Superior heat exchanger (having less pressure drop per unit heat transfer area) results in only 5% increase of plant performance even when it has 100% higher heat exchanger surface area.

Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces

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

Pruna, R., E-mail: rpruna@el.ub.edu; Palacio, F.; López, M.

2016-08-08

The electroactivity of nanostructured indium tin oxide (ITO) has been investigated for its further use in applications such as sensing biological compounds by the analysis of redox active molecules. ITO films were fabricated by using electron beam evaporation at different substrate temperatures and subsequently annealed for promoting their crystallization. The morphology of the deposited material was monitored by scanning electron microscopy, confirming the deposition of either thin films or nanowires, depending on the substrate temperature. Electrochemical surface characterization revealed a 45 % increase in the electroactive surface area of nanostructured ITO with respect to thin films, one third lower than themore » geometrical surface area variation determined by atomic force microscopy. ITO surfaces were functionalized with a model organic molecule known as 6-(ferrocenyl)hexanethiol. The chemical attachment was done by means of a glycidoxy compound containing a reactive epoxy group, the so-called 3-glycidoxypropyltrimethoxy-silane. ITO functionalization was useful for determining the benefits of nanostructuration on the surface coverage of active molecules. Compared to ITO thin films, an increase in the total peak height of 140 % was observed for as-deposited nanostructured electrodes, whereas the same measurement for annealed electrodes resulted in an increase of more than 400 %. These preliminary results demonstrate the ability of nanostructured ITO to increase the surface-to-volume ratio, conductivity and surface area functionalization, features that highly benefit the performance of biosensors.« less

Microscopic asperity contact and deformation of ultrahigh molecular weight polyethylene bearing surfaces.

PubMed

Wang, F C; Jin, Z M; McEwen, H M J; Fisher, J

2003-01-01

The effect of the roughness and topography of ultrahigh molecular weight polyethylene (UHMWPE) bearing surfaces on the microscopic contact mechanics with a metallic counterface was investigated in the present study. Both simple sinusoidal roughness forms, with a wide range of amplitudes and wavelengths, and real surface topographies, measured before and after wear testing in a simple pin-on-plate machine, were considered in the theoretical analysis. The finite difference method was used to solve the microscopic contact between the rough UHMWPE bearing surface and a smooth hard counterface. The fast Fourier transform (FFT) was used to cope with the large number of mesh points required to represent the surface topography of the UHMWPE bearing surface. It was found that only isolated asperity contacts occurred under physiological loading, and the real contact area was only a small fraction of the nominal contact area. Consequently, the average contact pressure experienced at the articulating surfaces was significantly higher than the nominal contact pressure. Furthermore, it was shown that the majority of asperities on the worn UHMWPE pin were deformed in the elastic region, and consideration of the plastic deformation only resulted in a negligible increase in the predicted asperity contact area. Microscopic asperity contact and deformation mechanisms may play an important role in the understanding of the wear mechanisms of UHMWPE bearing surfaces.

Effect of surface ozone exposures on vegetation grown in the southern Appalachian Mountains: identification of possible areas of concern

Treesearch

Allen S. Lefohn; William Jackson; Douglas S. Shadwick; H. Peter Knudsen

1997-01-01

The results described in this paper are derived from an analysis, for the 8-yr period 1983-1990, that combined experimental exposure-response effects data for deciduous and coniferous seedlings and/or trees with characterized O3 ambient exposure data for a local area and soil moisture to identify areas that may be at risk in the Southern...

Environmental Inventory and Analysis for Pine Bluff, Arkansas. Volume I. Pine Bluff Metropolitan Area, Arkansas Urban Water Management Study.

DTIC Science & Technology

1975-10-03

surface water systems include bacteria which cause typhoid fever, gastro- intestinal disorders, diarrheal diseases, nausea, dehydration , and kidney...industrial activity, although natural seepage, runoff from residential areas and decomposition of aquatic organisms may also be contributors. Waters with...Study Area. The movement of pesticides, however, is complex and dependent upon biological and photo-degradation, chemical oxidation and hydrolysis

Computer-aided analysis of LANDSAT data for surveying Texas coastal zone environments. [Pass Cavallo and Port O'Conner

NASA Technical Reports Server (NTRS)

Kristof, S. J. (Principal Investigator); Weismiller, R. A.

1977-01-01

The author has identified the following significant results. The study areas were Pass Cavallo and Port O'Connor. The following terrestrial and aquatic environments were discriminated: alternating beach ridges, swales, sand dunes, beach birms, deflation surfaces, land-water interface, urban, spoil areas, fresh and salt water marshes, grass and woodland, recently burned or grazed areas, submerged vegetation, and waterways.

Munsell color analysis of Landsat color-ratio-composite images of limonitic areas in southwest New Mexico

NASA Technical Reports Server (NTRS)

Kruse, F. A.

1985-01-01

The causes of color variations in the green areas on Landsat 4/5-4/6-6/7 (red-blue-green) color-ratio-composite (CRC) images, defined as limonitic areas, were investigated by analyzing the CRC images of the Lordsburg, New Mexico area. The red-blue-green additive color system was mathematically transformed into the cylindrical Munsell color coordinates (hue, saturation, and value), and selected areas were digitally analyzed for color variation. The obtained precise color characteristics were then correlated with properties of surface material. The amount of limonite (L) visible to the sensor was found to be the primary cause of the observed color differences. The visible L is, is turn, affected by the amount of L on the material's surface and by within-pixel mixing of limonitic and nonlimonitic materials. The secondary cause of variation was vegetation density, which shifted CRC hues towards yellow-green, decreased saturation, and increased value.

[Influence of surface chemical properties and pore structure characteristics of activated carbon on the adsorption of nitrobenzene from aqueous solution].

PubMed

Liu, Shou-Xin; Chen, Xi; Zhang, Xian-Quan

2008-05-01

Commercial activated carbon was treated by HNO3 oxidation and then subsequently heat treated under N2 atmosphere. Effect of surface chemical properties and pore structure on the adsorption performance of nitrobenzene was investigated. N2/77K adsorption isotherm and scanning electron microscopy (SEM) were used to characterize the pore structure and surface morphology of carbon. Boehm titration, Fourier transform infrared spectroscopy (FTIR), the point of zero charge (pH(PZC)) measurement and elemental analysis were used to characterize the surface properties. The results reveal that HNO3 oxidation can modify the surface chemical properties, increase the number of acidic surface oxygen-containing groups and has trivial effect on the pore structure of carbon. Further heat treatment can cause the decomposition of surface oxygen-containing groups, and increase the external surface area and the number of mesopores. Adsorption capacity of nitrobenzene on AC(NO-T), AC(raw) and AC(NO) was 1011.31, 483.09 and 321.54 mg x g(-1), respectively. Larger external surface area and the number of meso-pores, together with the less acid surface oxygen-containing groups were the main reason for the larger adsorption capacity AC(NO-T).

A high volume cost efficient production macrostructuring process. [for silicon solar cell surface treatment

NASA Technical Reports Server (NTRS)

Chitre, S. R.

1978-01-01

The paper presents an experimentally developed surface macro-structuring process suitable for high volume production of silicon solar cells. The process lends itself easily to automation for high throughput to meet low-cost solar array goals. The tetrahedron structure observed is 0.5 - 12 micron high. The surface has minimal pitting with virtually no or very few undeveloped areas across the surface. This process has been developed for (100) oriented as cut silicon. Chemi-etched, hydrophobic and lapped surfaces were successfully texturized. A cost analysis as per Samics is presented.

A GIS and statistical approach to identify variables that control water quality in hydrothermally altered and mineralized watersheds, Silverton, Colorado, USA

USGS Publications Warehouse

Yager, Douglas B.; Johnson, Raymond H.; Rockwell, Barnaby W.; Caine, Jonathan S.; Smith, Kathleen S.

2013-01-01

Hydrothermally altered bedrock in the Silverton mining area, southwest Colorado, USA, contains sulfide minerals that weather to produce acidic and metal-rich leachate that is toxic to aquatic life. This study utilized a geographic information system (GIS) and statistical approach to identify watershed-scale geologic variables in the Silverton area that influence water quality. GIS analysis of mineral maps produced using remote sensing datasets including Landsat Thematic Mapper, advanced spaceborne thermal emission and reflection radiometer, and a hybrid airborne visible infrared imaging spectrometer and field-based product enabled areas of alteration to be quantified. Correlations between water quality signatures determined at watershed outlets, and alteration types intersecting both total watershed areas and GIS-buffered areas along streams were tested using linear regression analysis. Despite remote sensing datasets having varying watershed area coverage due to vegetation cover and differing mineral mapping capabilities, each dataset was useful for delineating acid-generating bedrock. Areas of quartz–sericite–pyrite mapped by AVIRIS have the highest correlations with acidic surface water and elevated iron and aluminum concentrations. Alkalinity was only correlated with area of acid neutralizing, propylitically altered bedrock containing calcite and chlorite mapped by AVIRIS. Total watershed area of acid-generating bedrock is more significantly correlated with acidic and metal-rich surface water when compared with acid-generating bedrock intersected by GIS-buffered areas along streams. This methodology could be useful in assessing the possible effects that alteration type area has in either generating or neutralizing acidity in unmined watersheds and in areas where new mining is planned.

Morphology-Driven Control of Metabolite Selectivity Using Nanostructure-Initiator Mass Spectrometry

DOE PAGES

Gao, Jian; Louie, Katherine B.; Steinke, Philipp; ...

2017-05-26

Nanostructure-initiator mass spectrometry (NIMS) is a laser desorption/ionization analysis technique based on the vaporization of a nanostructure-trapped liquid "initiator" phase. Here we report an intriguing relationship between NIMS surface morphology and analyte selectivity. Scanning electron microscopy and spectroscopic ellipsometry were used to characterize the surface morphologies of a series of NIMS substrates generated by anodic electrochemical etching. Mass spectrometry imaging was applied to compare NIMS sensitivity of these various surfaces toward the analysis of diverse analytes. The porosity of NIMS surfaces was found to increase linearly with etching time where the pore size ranged from 4 to 12 nm withmore » corresponding porosities estimated to be 7-70%. Surface morphology was found to significantly and selectively alter NIMS sensitivity. The small molecule ( < 2k Da) sensitivity was found to increase with increased porosity, whereas low porosity had the highest sensitivity for the largest molecules examined. Estimation of molecular sizes showed that this transition occurs when the pore size is < 3× the maximum of molecular dimensions. While the origins of selectivity are unclear, increased signal from small molecules with increased surface area is consistent with a surface area restructuring-driven desorption/ionization process where signal intensity increases with porosity. In contrast, large molecules show highest signal for the low-porosity and small-pore-size surfaces. We attribute this to strong interactions between the initiator-coated pore structures and large molecules that hinder desorption/ionization by trapping large molecules. This finding may enable us to design NIMS surfaces with increased specificity to molecules of interest.« less

Preliminary study of Songa-Wayaua geothermal prospect area using volcanostratigraphy and remote sensing analysis

NASA Astrophysics Data System (ADS)

Asokawaty, Ribka; Nugroho, Indra; Satriana, Joshua; Hafidz, Muhamad; Suryantini

2017-12-01

Songa-Wayaua geothermal prospect area is located on Bacan Island, Northern Molluca Province. Geothermal systems in this area associated with three Quartenary volcanoes, such as Mt. Pele-pele, Mt. Lansa, and Mt. Bibinoi. Based on literature study, five surface manifestations such as hot springs and alteration occurred within this area. The active manifestations indicate that Songa-Wayaua area has potential geothermal resource. This study objective is to evaluate Songa-Wayaua geothermal system on preliminary study stage by using volcanostratigraphy and remote sensing analysis to delineate the boundary of geothermal system area. The result of this study showed that Songa-Wayaua prospect area has four heat sources potential (e.g. Pele-pele Hummock, Lansa Hummock, Songa Hummock, and Bibinoi Hummock), controlled by geological structure presented by Pele-pele Normal Fault, and had three places as the recharge and discharge area which are very fulfilling as a geothermal system.

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.

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.

Temporal and spatial assessment of river surface water quality using multivariate statistical techniques: a study in Can Tho City, a Mekong Delta area, Vietnam.

PubMed

Phung, Dung; Huang, Cunrui; Rutherford, Shannon; Dwirahmadi, Febi; Chu, Cordia; Wang, Xiaoming; Nguyen, Minh; Nguyen, Nga Huy; Do, Cuong Manh; Nguyen, Trung Hieu; Dinh, Tuan Anh Diep

2015-05-01

The present study is an evaluation of temporal/spatial variations of surface water quality using multivariate statistical techniques, comprising cluster analysis (CA), principal component analysis (PCA), factor analysis (FA) and discriminant analysis (DA). Eleven water quality parameters were monitored at 38 different sites in Can Tho City, a Mekong Delta area of Vietnam from 2008 to 2012. Hierarchical cluster analysis grouped the 38 sampling sites into three clusters, representing mixed urban-rural areas, agricultural areas and industrial zone. FA/PCA resulted in three latent factors for the entire research location, three for cluster 1, four for cluster 2, and four for cluster 3 explaining 60, 60.2, 80.9, and 70% of the total variance in the respective water quality. The varifactors from FA indicated that the parameters responsible for water quality variations are related to erosion from disturbed land or inflow of effluent from sewage plants and industry, discharges from wastewater treatment plants and domestic wastewater, agricultural activities and industrial effluents, and contamination by sewage waste with faecal coliform bacteria through sewer and septic systems. Discriminant analysis (DA) revealed that nephelometric turbidity units (NTU), chemical oxygen demand (COD) and NH₃ are the discriminating parameters in space, affording 67% correct assignation in spatial analysis; pH and NO₂ are the discriminating parameters according to season, assigning approximately 60% of cases correctly. The findings suggest a possible revised sampling strategy that can reduce the number of sampling sites and the indicator parameters responsible for large variations in water quality. This study demonstrates the usefulness of multivariate statistical techniques for evaluation of temporal/spatial variations in water quality assessment and management.

Morphological Properties of Siloxane-Hydrogel Contact Lens Surfaces.

PubMed

Stach, Sebastian; Ţălu, Ştefan; Trabattoni, Silvia; Tavazzi, Silvia; Głuchaczka, Alicja; Siek, Patrycja; Zając, Joanna; Giovanzana, Stefano

2017-04-01

The aim of this study was to quantitatively characterize the micromorphology of contact lens (CL) surfaces using atomic force microscopy (AFM) and multifractal analysis. AFM and multifractal analysis were used to characterize the topography of new and worn siloxane-hydrogel CLs made of Filcon V (I FDA group). CL surface roughness was studied by AFM in intermittent-contact mode, in air, on square areas of 25 and 100 μm 2 , by using a Nanoscope V MultiMode (Bruker). Detailed surface characterization of the surface topography was obtained using statistical parameters of 3-D (three-dimensional) surface roughness, in accordance with ISO 25178-2: 2012. Before wear, the surface was found to be characterized by out-of-plane and sharp structures, whilst after a wear of 8 h, two typical morphologies were observed. One morphology (sharp type) has a similar aspect as the unworn CLs and the other morphology (smooth type) is characterized by troughs and bumpy structures. The analysis of the AFM images revealed a multifractal geometry. The generalized dimension D q and the singularity spectrum f(α) provided quantitative values that characterize the local scale properties of CL surface geometry at nanometer scale. Surface statistical parameters deduced by multifractal analysis can be used to assess the CL micromorphology and can be used by manufacturers in developing CLs with improved surface characteristics. These parameters can also be used in understanding the tribological interactions of the back surface of the CL with the corneal surface and the front surface of the CL with the under-surface of the eyelid (friction, wear, and micro-elastohydrodynamic lubrication at a nanometer scale).

Comparison of Spacecraft Contamination Models with Well-Defined Flight Experiment

NASA Technical Reports Server (NTRS)

Pippin, G. H.

1998-01-01

The report presents analyzed surface areas on particular experiment trays from the Long Duration Exposure Facility (LDEF) for silicone-based molecular contamination. The trays for examination were part of the Ultra-Heavy Cosmic Ray Experiment (UHCRE). These particular trays were chosen because each tray was identical to the others in construction, and the materials on each tray were well known, documented, and characterized. In particular, a known specific source of silicone contamination was present on each tray. Only the exposure conditions varied from tray to tray. The results of post-flight analyses of surfaces of three trays were compared with the predictions of the three different spacecraft molecular contamination models. Phase one tasks included: 1) documenting the detailed geometry of the hardware; 2) determining essential properties of the anodized aluminum, Velcro(Tm), silverized Teflon(Tm), silicone gaskets, and DC6-1104(Tm) silicone adhesive materials used to make the trays, tray covers, and thermal control blankets; 3) selecting and removing areas from each tray; and 4) beginning surface analysis of the selected tray walls. Phase two tasks included: 1) completion of surface analysis measurements of the selected tray surface, 2) obtaining auger depth profiles at selected locations, and 3) running versions of the ISEM, MOFLUX, and PLIMP (Plume Impingement) contamination prediction models and making comparisons with experimental results.

The Circumpolar Arctic Vegetation Map: A tool for analysis of change in permafrost regions

NASA Astrophysics Data System (ADS)

Walker, D. A.; Raynolds, M. K.; Maier, H. A.

2003-12-01

Arctic vegetation occurs beyond the northern limit of trees, in areas that have an Arctic climate and Arctic flora. Here we present an overview of the recently published Circumpolar Arctic Vegetation Map (CAVM), an area analysis of the vegetation map, and a discussion of its potential for analysis of change in the Arctic. Six countries have Arctic tundra vegetation, Canada, Greenland, Iceland, Russia, Norway (Svalbard), and the US (Total Arctic area = 7.1 million km2). Some treeless areas, such as most of Iceland and the Aluetian Islands are excluded from the map because they lack an Arctic climate. The CAVM divides the Arctic into five bioclimate subzones, A thru E (Subzone A is the coldest and Subzone E is the warmest), based on a combination of summer temperature and vegetation. Fifteen vegetation types are mapped based on the dominant plant growth forms. More detailed, plant-community-level, information is contained in the database used to construct the map. The reverse side of the vegetation map has a false-color infrared image constructed from Advanced Very-High Resolution (AVHRR) satellite-derived raster data, and maps of bioclimate subzones, elevation, landscape types, lake cover, substrate chemistry, floristic provinces, the maximum normalized difference vegetation index (NDVI), and aboveground phytomass. The vegetation map was analyzed by vegetation type and biomass for each county, bioclimate subzone, and floristic province. Biomass distribution was analyzed by means of a correlation between aboveground phytomass and the normalized difference vegetation index (NDVI), a remote-sensing index of surface greenness. Biomass on zonal surfaces roughly doubles within each successively warmer subzone, from about 50 g m-2 in Subzone A to 800 g m-2- in Subzone E. But the pattern of vegetation increase is highly variable, and depends on a number of other factors. The most important appears to be the glacial history of the landscape. Areas that were glaciated during the late-Pleistocene, such as Canada, Svalbard, and Greenland, do not show such strong increases in NDVI with temperature as do areas that were not glaciated. Abundant lakes and rocky surfaces limit the greenness of these recently glaciated surfaces. The highest NDVI and phytomass are found in non-glaciated regions of Alaska and Russia. Soil acidity also affects NDVI patterns. In Subzone D, where the NDVI/ soil acidity relationship has been studied most closely, NDVI is lower on nonacidic surfaces. This has been attributed to fewer shrubs and higher proportion of graminoids (more standing dead sedge leaves) in nonacidic areas. This trend is probably caused by generally drier soils, with less production, on limestone-derived soils. The trend is less clear in Subzone E because of fewer nonacidic surfaces, and the abundance of glacial lakes with low NDVI on the acidic shield areas of Canada. Time series analysis of trends in NDVI in Subzones C, D, and E in Alaska have shown a 17% increase in the NDVI over the 21-year record. The increases have been greatest in moist nonacidic tundra. Future analyses of the circumpolar database will be directed at examining which geographic regions and vegetation types have shown the strongest increases, and how these are correlated with temperature changes.

What Is a Hill? An Analysis of the Meanings of Generic Topographic Terms

DTIC Science & Technology

1985-08-01

to describe the di,.ferent characters of forms. FLAT: An area or surface with gantle, non-varying slope, that is highly platykurtic but not...Slo;e Change Index value of zero. ROLLING: A surface without elevated or Inverted forms, with platykurtic slo a Slope Ctange Index value of zero and...and contour planes of similar extent. POCKMARKEC (pitted): A surface that has within its contour repeated, small, circular or elliptical platykurtic

Coastal groundwater/surface-water interactions: a Great Lakes case study

USGS Publications Warehouse

Neff, Brian P.; Haack, Sheridan K.; Rosenberry, Donald O.; Savino, Jacqueline F.; Lundstrom, Scott C.

2006-01-01

Key similarities exist between marine and Great Lakes coastal environments. Water and nutrient fluxes across lakebeds in the Great Lakes are influenced by seiche and wind set-up and set-down, analogous to tidal influence in marine settings. Groundwater/surface-water interactions also commonly involve a saline-fresh water interface, although in the Great-Lakes cases, it is groundwater that is commonly saline and surface water that is fresh. Evapotranspiration also affects nearshore hydrology in both settings. Interactions between groundwater and surface water have recently been identified as an important component of ecological processes in the Great Lakes. Water withdrawals and the reversal of the groundwater/surface water seepage gradient are also common to many coastal areas around the Great Lakes. As compared to surface water, regional groundwater that discharges to western Lake Erie from Michigan is highly mineralized. Studies conducted by the U.S. Geological Survey at Erie State Game Area in southeastern Michigan, describe groundwater flow dynamics and chemistry, shallow lake-water chemistry, and fish and invertebrate communities. Results presented here provide an overview of recent progress of ongoing interdisciplinary studies of Great Lakes nearshore systems and describe a conceptual model that identifies relations among geologic, hydrologic, chemical, and biological processes in the coastal habitats of Lake Erie. This conceptual model is based on analysis of hydraulic head in piezometers at the study site and chemical analysis of deep and shallow coastal groundwater.

Analysis

NASA Astrophysics Data System (ADS)

Abdelazeem, Maha; El-Sawy, El-Sawy K.; Gobashy, Mohamed M.

2013-06-01

Ar Rika fault zone constitutes one of the two major parts of the NW-SE Najd fault system (NFS), which is one of the most prominent structural features located in the east of the center of the Arabian Shield, Saudi Arabia. By using Enhancement Thematic Mapper data (ETM+) and Principle Component Analysis (PCA), surface geological characteristics, distribution of rock types, and the different trends of linear features and faults are determined in the study area. First and second order magnetic gradients of the geomagnetic field at the North East of Wadi Ar Rika have been calculated in the frequency domain to map both surface and subsurface lineaments and faults. Lineaments as deduced from previous studies, suggest an extension of the NFS beneath the cover rocks in the study area. In the present study, integration of magnetic gradients and remote sensing analysis that resulted in different valuable derivative maps confirm the subsurface extension of some of the surface features. The 3D Euler deconvolution, the total gradient, and the tilt angle maps have been utilized to determine accurately the distribution of shear zones, the tectonic implications, and the internal structures of the terranes in the Ar Rika quadrangle in three dimensions.

Different Patterns of the Urban Heat Island Intensity from Cluster Analysis

NASA Astrophysics Data System (ADS)

Silva, F. B.; Longo, K.

2014-12-01

This study analyzes the different variability patterns of the Urban Heat Island intensity (UHII) in the Metropolitan Area of Rio de Janeiro (MARJ), one of the largest urban agglomerations in Brazil. The UHII is defined as the difference in the surface air temperature between the urban/suburban and rural/vegetated areas. To choose one or more stations that represent those areas we used the technique of cluster analysis on the air temperature observations from 14 surface weather stations in the MARJ. The cluster analysis aims to classify objects based on their characteristics, gathering similar groups. The results show homogeneity patterns between air temperature observations, with 6 homogeneous groups being defined. Among those groups, one might be a natural choice for the representative urban area (Central station); one corresponds to suburban area (Afonsos station); and another group referred as rural area is compound of three stations (Ecologia, Santa Cruz and Xerém) that are located in vegetated regions. The arithmetic mean of temperature from the three rural stations is taken to represent the rural station temperature. The UHII is determined from these homogeneous groups. The first UHII is estimated from urban and rural temperature areas (Case 1), whilst the second UHII is obtained from suburban and rural temperature areas (Case 2). In Case 1, the maximum UHII occurs in two periods, one in the early morning and the other at night, while the minimum UHII occurs in the afternoon. In Case 2, the maximum UHII is observed during afternoon/night and the minimum during dawn/early morning. This study demonstrates that the stations choice reflects different UHII patterns, evidencing that distinct behaviors of this phenomenon can be identified.

Investigation of possible effects of surface coal mining on hydrology and landscape stability in part of the Powder River structural basin, northeastern Wyoming

USGS Publications Warehouse

Bloyd, R.M.; Daddow, P.B.; Jordon, P.R.; Lowham, H.W.

1986-01-01

The effects of surface coal mining on the surface- and groundwater systems in a 5,400 sq mi area in the Powder River Basin, Wyoming, that includes 20 major coal mines were evaluated using three approaches: A surface water model, a landscape-stability analysis, and a groundwater model. A surface water model was developed for the Belle Fourche River basin. The Hydrological Simulation Program-Fortran model was used to simulate changes in streamflow and changes in dissolved-solids and sulfate concentrations. Simulated streamflows resulting from less than average rainfall were small, changes in flow from premining to during-mining and postmining conditions were less than 2.5%, and changes in mean dissolved-solids and sulfate concentrations ranged from 1 to 7%. A landscape-stability analysis resulted in regression relations to aid in the reconstruction of reclaimed drainage networks. Hypsometric analyses indicate the larger basins are relatively stable, and statistical data from these basins may be used to design the placement of material within a mined basin to approximate natural, stable landscapes in the area. The attempt to define and simulate the groundwater system in the area using a groundwater-flow model was unsuccessful. The steady-state groundwater-flow model could not be calibrated. The modeling effort failed principally because of insufficient quantity and quality of data to define the spatial distribution of aquifer properties; the hydraulic-head distribution within and between aquifers; and the rates of groundwater recharge and discharge, especially for steady-state conditions. (USGS)

Systematic determination of thyroid volume by ultrasound examination from infancy to adolescence in Japan: the Fukushima Health Management Survey.

PubMed

Suzuki, Satoru; Midorikawa, Sanae; Fukushima, Toshihiko; Shimura, Hiroki; Ohira, Tetsuya; Ohtsuru, Akira; Abe, Masafumi; Shibata, Yoshisada; Yamashita, Shunichi; Suzuki, Shinichi

2015-01-01

Although several reports have defined normal thyroid volume depending on either age or body surface, there are no sequential reference values on childhood thyroid volume evaluated by using ultrasonography and epidemiological analysis in Japan. The aim of the present study was to establish updated reference values for thyroid volume by ultrasound examination and epidemiological analysis in 0-19 year-old Japanese children. It is based on a cross-sectional study conducted from October 9, 2011 to March 31, 2012. The subjects were 38,063 children who were examined by ultrasonography as the initial preliminary survey of the Fukushima Health Management Survey in October 9, 2011 to March 31, 2012. The width, thickness, and height of each lobe were measured and the volume of each lobe was calculated by the mean of the elliptical shape volume formula. The values of thyroid volume at the 2.5 and 97.5 percentiles of age and body surface area for each gender group were obtained from 0-19 year-old children. Positive correlation was observed between thyroid volume and either age or body surface. The right lobe was significantly larger than the left lobe. The thyroid volume in females was larger than that in males after adjusting body surface area. The reference values of childhood thyroid for each age or body surface area were obtained by this extensive survey using ultrasound. These reference values may be used to define the normal size of thyroid gland by echosonography in Japanese children, although thyroid volume may be affected by dimorphic factors such as sex hormones.

Hydrogeology and analysis of ground-water withdrawal in the Mendenhall-D'Lo area, Simpson County, Mississippi

USGS Publications Warehouse

Strom, E.W.; Oakley, W.T.

1995-01-01

The cities of Mendenhall and D'Lo, located in Simpson County, rely on ground water for their public supply and industrial needs. Most of the ground water comes from an aquifer of Miocene age. A study began in 1991 to describe the hydrogeology, analyze effects of ground-water withdrawal by making a drawdown map, and estimate the effects increased ground-water withdrawal might have on water levels in the Miocene age aquifer in the Mendenhall-D'Lo area. The most significant withdrawals of ground water in the study area are from 10 wells screened in the lower sand of the Catahoula Formation of Miocene age. Analysis of the effect of withdrawals from the 10 wells was made using the Theis non- equilibrium equation and applying the principle of superposition. Analysis of 1994 conditions was based on the pumpage history and aquifer properties deter- mined for each well. The drawdown surface resulting from the analysis indicates three general cones of depression. One cone is in the northwestern D'Lo area, one in the south-central Mendenhall area, and one about 1-1/2 miles east of Mendenhall. Calculated drawdown ranges from 21 to 47 feet. Potential drawdown-surface maps were made for 10 years and 20 years beyond 1994 using a constant pumpage. The map made for 10 years beyond 1994 indicates an average total increase in drawdown of about 5.3 feet. The map made for 20 years beyond 1994 indicates an average total increase in drawdown of about 7.3 feet.

Exploration for fossil and nuclear fuels from orbital altitudes

NASA Technical Reports Server (NTRS)

Short, N. M.

1975-01-01

A review of satellite-based photographic (optical and infrared) and microwave exploration and large-area mapping of the earth's surface in the ERTS program. Synoptic cloud-free coverage of large areas has been achieved with planimetric vertical views of the earth's surface useful in compiling close-to-orthographic mosaics. Radar penetration of cloud cover and infrared penetration of forest cover have been successful to some extent. Geological applications include map editing (with corrections in scale and computer processing of images), landforms analysis, structural geology studies, lithological identification, and exploration for minerals and fuels. Limitations of the method are noted.

Acute and subchronic toxicity analysis of surface modified paclitaxel attached hydroxyapatite and titanium dioxide nanoparticles.

PubMed

Venkatasubbu, Gopinath Devanand; Ramasamy, S; Gaddam, Pramod Reddy; Kumar, J

2015-01-01

Nanoparticles are widely used for targeted drug delivery applications. Surface modification with appropriate polymer and ligands is carried out to target the drug to the affected area. Toxicity analysis is carried out to evaluate the safety of the surface modified nanoparticles. In this study, paclitaxel attached, folic acid functionalized, polyethylene glycol modified hydroxyapatite and titanium dioxide nanoparticles were used for targeted drug delivery system. The toxicological behavior of the system was studied in vivo in rats and mice. Acute and subchronic studies were carried out. Biochemical, hematological, and histopathological analysis was also done. There were no significant alterations in the biochemical parameters at a low dosage. There was a small change in alkaline phosphatase (ALP) level at a high dosage. The results indicate a safe toxicological profile.

Modelling the degree of porosity of the ceramic surface intended for implants.

PubMed

Stach, Sebastian; Kędzia, Olga; Garczyk, Żaneta; Wróbel, Zygmunt

2018-05-18

The main goal of the study was to develop a model of the degree of surface porosity of a biomaterial intended for implants. The model was implemented using MATLAB. A computer simulation was carried out based on the developed model, which resulted in a two-dimensional image of the modelled surface. Then, an algorithm for computerised image analysis of the surface of the actual oxide bioceramic layer was developed, which enabled determining its degree of porosity. In order to obtain the confocal micrographs of a few areas of the biomaterial, measurements were performed using the LEXT OLS4000 confocal laser microscope. The image analysis was carried out using MountainsMap Premium and SPIP. The obtained results allowed determining the input parameters of the program, on the basis of which porous biomaterial surface images were generated. The last part of the study involved verification of the developed model. The modelling method was tested by comparing the obtained results with the experimental data obtained from the analysis of surface images of the test material.

Study of application of ERTS-A imagery to fracture-related mine safety hazards in the coal mining industry

NASA Technical Reports Server (NTRS)

Wier, C. E.; Wobber, F. J.; Russell, O. R.; Martin, K. R. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Mined land reclamation analysis procedures developed within the Indiana portion of the Illinois Coal Basin were independently tested in Ohio utilizing 1:80,000 scale enlargements of ERTS-1 image 1029-15361-7 (dated August 21, 1972). An area in Belmont County was selected for analysis due to the extensive surface mining and the different degrees of reclamation occurring in this area. Contour mining in this area provided the opportunity to extend techniques developed for analysis of relatively flat mining areas in Indiana to areas of rolling topography in Ohio. The analysts had no previous experience in the area. Field investigations largely confirmed office analysis results although in a few areas estimates of vegetation percentages were found to be too high. In one area this error approximated 25%. These results suggest that systematic ERTS-1 analysis in combination with selective field sampling can provide reliable vegetation percentage estimates in excess of 25% accuracy with minimum equipment investment and training. The utility of ERTS-1 for practical and reasonably reliable update of mined lands information for groups with budget limitations is suggested. Many states can benefit from low cost updates using ERTS-1 imagery from public sources.

Bubbles and Dust: Dissolution Rates of Unhydrated Volcanic Ash as a Function of Morphology, Composition, and Particle Size

NASA Astrophysics Data System (ADS)

Wygel, C. M.; Sahagian, D. L.

2017-12-01

Volcanic eruptions are natural hazards due to their explosive nature and widespread transportation and deposition of ash particles. After deposition and subsequent leaching in soils or water bodies, ash deposition positively (nutrients) and negatively (contaminants) impacts the health of flora and fauna, including humans. The effects of ash leachates have been difficult to replicate in field and laboratory studies due to the many complexities and differences between ash particles. Ash morphology is characteristic for each eruption, dependent upon eruption energy, and should play a critical role in determining leaching rates. Morphology reflects overall particle surface area, which is strongly influenced by the presence of surface dust. In addition, ash composition, which in part controls morphology and particle size, may also affect leaching rates. This study determines the extent to which ash morphology, surface area, composition, and particle size control ash dissolution rates. Further, it is necessary to determine whether compound vesicular ash particles permit water into their interior structures to understand if both the internal and external surface areas are available for leaching. To address this, six fresh, unhydrated ash samples from diverse volcanic environments and a large range in morphology, from Pele's spheres to vesicular compound ash, are tested in the laboratory. Ash morphology was characterized on the Scanning Electron Microscope (SEM) before and after leaching and surface area was quantified by Brunauer Emmett Teller (BET) analysis and with geometric calculations. Column Leachate Tests (CLT) were conducted to compare leaching rates over a range of basaltic to silicic ashes as a function of time and surface area, to recreate the effects of ash deposition in diverse volcanic environments. After the CLT, post-leaching water analyses were conducted by Ion Coupled Plasma-Mass Spectrometry (ICP-MS) and Ion Chromatography (IC). We find that leaching rates are correlated to characteristic surface area of ash particles.

Toward surface quantification of liver fibrosis progression

NASA Astrophysics Data System (ADS)

He, Yuting; Kang, Chiang Huen; Xu, Shuoyu; Tuo, Xiaoye; Trasti, Scott; Tai, Dean C. S.; Raja, Anju Mythreyi; Peng, Qiwen; So, Peter T. C.; Rajapakse, Jagath C.; Welsch, Roy; Yu, Hanry

2010-09-01

Monitoring liver fibrosis progression by liver biopsy is important for certain treatment decisions, but repeated biopsy is invasive. We envision redefinition or elimination of liver biopsy with surface scanning of the liver with minimally invasive optical methods. This would be possible only if the information contained on or near liver surfaces accurately reflects the liver fibrosis progression in the liver interior. In our study, we acquired the second-harmonic generation and two-photon excitation fluorescence microscopy images of liver tissues from bile duct-ligated rat model of liver fibrosis. We extracted morphology-based features, such as total collagen, collagen in bile duct areas, bile duct proliferation, and areas occupied by remnant hepatocytes, and defined the capsule and subcapsular regions on the liver surface based on image analysis of features. We discovered a strong correlation between the liver fibrosis progression on the anterior surface and interior in both liver lobes, where biopsy is typically obtained. The posterior surface exhibits less correlation with the rest of the liver. Therefore, scanning the anterior liver surface would obtain similar information to that obtained from biopsy for monitoring liver fibrosis progression.

Landscape functionality of plant communities in the Impala Platinum mining area, Rustenburg.

PubMed

van der Walt, L; Cilliers, S S; Kellner, K; Tongway, D; van Rensburg, L

2012-12-30

The tremendous growth of the platinum mining industry in South Africa has affected the natural environment adversely. The waste produced by platinum mineral processing is alkaline, biologically sterile and has a low water-holding capacity. These properties in the environment may constitute dysfunctional areas that will create 'leaky' and dysfunctional landscapes, limiting biological development. Landscape Function Analysis (LFA) is a monitoring procedure that assesses the degradation of landscapes, as brought about by human, animal and natural activities, through rapidly assessing certain soil surface indicators which indicate the biophysical functionality of the system. The "Trigger-Transfer-Reserve-Pulse" (TTRP) conceptual framework forms the foundation for assessing landscape function when using LFA. The two main aspects of this framework are the loss of resources from the system and the utilisation of resources by the system. After a survey of landscape heterogeneity to reflect the spatial organisation of the landscape, soil surface indicators are assessed within different patch types (identifiable units that retains resources that pass through the system) and interpatches (units between patches where vital resources are not retained, but lost) to assess the capacity of patches with various physical properties in regulating the effectiveness of resource control in the landscape. Indices describing landscape organisation are computed by a spreadsheet analysis, as well as soil surface quality indices. When assembled in different combinations, three indices emerge that reflect soil productive potential, namely: the (1) surface stability, (2) infiltration capacity, and (3) the nutrient cycling potential of the landscape. In this study we compared the landscape functionality of natural thornveld areas, rehabilitated opencast mines and rehabilitated slopes of tailings dams in the area leased for mining in the Rustenburg area. Our results show that the rehabilitated areas had a higher total SSA functionality due to higher infiltration and nutrient cycling indices than the natural thornveld landscapes. The length of interpatches and the width of patches greatly influenced the landscape function of the studied areas. The natural thornveld areas had a marginally higher total patch area than the rehabilitated areas. Vegetated patches (grass-, sparse grass-, grassy forb-, and grassy shrub-patches) generally scored the highest functionality indices, whilst bare soil interpatches contributed to the landscape functionality of the various plant communities the least. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

The use of LANDSAT imagery in relation to air survey imagery for terrain analysis in northwest Queensland, Australia, volume 1

NASA Technical Reports Server (NTRS)

Cole, M. M.; Owen-Jones, E. S. (Principal Investigator)

1977-01-01

The author has identified the following significant results. Distinctive spectral signatures discriminated areas underlain by distinctive lithological/stratigraphical units where bedrock either outcrops or is relatively near to surface in the Lady Annie-Mt. Gordon fault zone, the Mary Kathleen, and Dugald River-Naraku areas. Spectral signatures associated with discrete plant communities distinguished different types of superficial deposits over the Cloncurry Plains. Distinctive spectral signatures also revealed the presence and nature of concealed bedrock beneath cover of residuum and superficial deposits where this is relatively thin in the Cloncurry Plains. Major faults were clearly displayed in areas of outcropping and near surface bedrock. Sets of lineaments with preferred orientations were identified in the Lady Annie and Dugald River areas. Known base metal deposits occur along these features.

Measuring toothbrush interproximal penetration using image analysis

NASA Astrophysics Data System (ADS)

Hayworth, Mark S.; Lyons, Elizabeth K.

1994-09-01

An image analysis method of measuring the effectiveness of a toothbrush in reaching the interproximal spaces of teeth is described. Artificial teeth are coated with a stain that approximates real plaque and then brushed with a toothbrush on a brushing machine. The teeth are then removed and turned sideways so that the interproximal surfaces can be imaged. The areas of stain that have been removed within masked regions that define the interproximal regions are measured and reported. These areas correspond to the interproximal areas of the tooth reached by the toothbrush bristles. The image analysis method produces more precise results (10-fold decrease in standard deviation) in a fraction (22%) of the time as compared to our prior visual grading method.

Constellation Architecture Team-Lunar: Lunar Habitat Concepts

NASA Technical Reports Server (NTRS)

Toups, Larry; Kennedy, Kriss J.

2008-01-01

This paper will describe lunar habitat concepts that were defined as part of the Constellation Architecture Team-Lunar (CxAT-Lunar) in support of the Vision for Space Exploration. There are many challenges to designing lunar habitats such as mission objectives, launch packaging, lander capability, and risks. Surface habitats are required in support of sustaining human life to meet the mission objectives of lunar exploration, operations, and sustainability. Lunar surface operations consist of crew operations, mission operations, EVA operations, science operations, and logistics operations. Habitats are crewed pressurized vessels that include surface mission operations, science laboratories, living support capabilities, EVA support, logistics, and maintenance facilities. The challenge is to deliver, unload, and deploy self-contained habitats and laboratories to the lunar surface. The CxAT-Lunar surface campaign analysis focused on three primary trade sets of analysis. Trade set one (TS1) investigated sustaining a crew of four for six months with full outpost capability and the ability to perform long surface mission excursions using large mobility systems. Two basic habitat concepts of a hard metallic horizontal cylinder and a larger inflatable torus concept were investigated as options in response to the surface exploration architecture campaign analysis. Figure 1 and 2 depicts the notional outpost configurations for this trade set. Trade set two (TS2) investigated a mobile architecture approach with the campaign focused on early exploration using two small pressurized rovers and a mobile logistics support capability. This exploration concept will not be described in this paper. Trade set three (TS3) investigated delivery of a "core' habitation capability in support of an early outpost that would mature into the TS1 full outpost capability. Three core habitat concepts were defined for this campaign analysis. One with a four port core habitat, another with a 2 port core habitat, and the third investigated leveraging commonality of the lander ascent module and airlock pressure vessel hard shell. The paper will describe an overview of the various habitat concepts and their functionality. The Crew Operations area includes basic crew accommodations such as sleeping, eating, hygiene and stowage. The EVA Operations area includes additional EVA capability beyond the suit-port airlock function such as redundant airlock(s), suit maintenance, spares stowage, and suit stowage. The Logistics Operations area includes the enhanced accommodations for 180 days such as closed loop life support systems hardware, consumable stowage, spares stowage, interconnection to the other Hab units, and a common interface mechanism for future growth and mating to a pressurized rover. The Mission & Science Operations area includes enhanced outpost autonomy such as an IVA glove box, life support, and medical operations.

Modelling Mean Albedo of Individual Roofs in Complex Urban Areas Using Satellite Images and Airborne Laser Scanning Point Clouds

NASA Astrophysics Data System (ADS)

Kalantar, B.; Mansor, S.; Khuzaimah, Z.; Sameen, M. Ibrahim; Pradhan, B.

2017-09-01

Knowledge of surface albedo at individual roof scale is important for mitigating urban heat islands and understanding urban climate change. This study presents a method for quantifying surface albedo of individual roofs in a complex urban area using the integration of Landsat 8 and airborne LiDAR data. First, individual roofs were extracted from airborne LiDAR data and orthophotos using optimized segmentation and supervised object based image analysis (OBIA). Support vector machine (SVM) was used as a classifier in OBIA process for extracting individual roofs. The user-defined parameters required in SVM classifier were selected using v-fold cross validation method. After that, surface albedo was calculated for each individual roof from Landsat images. Finally, thematic maps of mean surface albedo of individual roofs were generated in GIS and the results were discussed. Results showed that the study area is covered by 35% of buildings varying in roofing material types and conditions. The calculated surface albedo of buildings ranged from 0.16 to 0.65 in the study area. More importantly, the results indicated that the types and conditions of roofing materials significantly effect on the mean value of surface albedo. Mean albedo of new concrete, old concrete, new steel, and old steel were found to be equal to 0.38, 0.26, 0.51, and 0.44 respectively. Replacing old roofing materials with new ones should highly prioritized.

AFM AND XPS Characterization of Zinc-Aluminum Alloy Coatings with Attention to Surface Dross and Flow Lines

NASA Astrophysics Data System (ADS)

Harding, Felipe A.; Alarcon, Nelson A.; Toledo, Pedro G.

Surfaces of various zinc-aluminum alloy (Zn-Al) coated steel samples are studied with attention to foreign surface dross by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS/ESCA). AFM topographic maps of zinc-aluminum alloy surfaces free of dross reveal the perfect nanoscale details of two kinds of dendrites: branched and globular. In all magnifications the dendrites appear smooth and, in general, very clean. XPS analysis of the extreme surface of a Zn-Al sample reveals Al, Zn, Si and O as the main components. The XPS results show no segregation or separation of phases other than those indicated by the ternary Al-Zn-Si diagram. For surfaces of Zn-Al plagued with impurities, high resolution AFM topographic maps reveal three situations: (1) areas with well-defined dendrites, relatively free of dross; (2) areas with small, millimeter-sized black spots known as dross; and (3) areas with large black stains, known as flow lines. Dendrite deformation and dross accumulation increase notably in the neighborhood, apparently clean to the naked eye, of dross or flow lines. XPS results of areas with dross and flow lines indicate unacceptable high concentration of Si and important Si phase separation. These results, in the light of AFM work, reveal that dross and flow lines are a consequence of a high local concentration of Si from high melting point silica and silicate impurities in the Zn-Al alloy source.

Terrain profiling from Seasat altimetry

NASA Technical Reports Server (NTRS)

Brooks, R. L.

1981-01-01

To determine their applicability for terrain profiling, Seasat altimeter measurements were analyzed for the following geographic areas: (1) Andean salars of southern Bolivia; (2) Alaska; (3) south-central Arizona; (4) imperial Valley of California; (5) Yuma Valley of Arizona; and (6) Great Salt Lake Desert. Analysis of the data over all of these geographic areas shows that the satellite altimeter servo did not respond quickly enough to changing terrain features. However, it is demonstrated that retracking of the archived surface return waveforms yields surface elevations over smooth terrain accurate to + or - 1 m when correlated with large scale maps. The retracking algorithm used and its verification over the salars of southern Bolivia are described. Results are presented for each of the six geographic areas.

Atmospheric Dispersion Modeling of 137Cs generated from Nuclear Spent Fuel under Hypothetic Accidental Condition in the BNPP Area

NASA Astrophysics Data System (ADS)

Lee, Jongkuk; Lee, Kwan-Hee; Yook, Daesik; Kim, Sung Il; Lee, Byung Soo

2016-04-01

This study presents the results of atmosphere dispersion modeling using CALPUFF code that are based on computational simulation to evaluate the environmental characteristics of the Barakah nuclear power plant (BNPP) in west area of UAE. According to meteorological data analysis (2012~2013), the winds from the north(7.68%) and west(9.05%) including NNW(41.63%), NW(28.55%), and WNW(6.31%) winds accounted for more than 90% of the wind directions. East(0.2%) and south(0.6%) direction wind, including ESE(0.31%), SE(0.38%), and SSE(0.38%) were rarely distributed during the simulation period. Seasonal effects were not showed. However, a discrepancy in the tendency between daytime and night-time was observed. Approximately 87% of the wind speed was distributed below 5.4m/s (17%, 47% and 23% between the speeds of 0.5-1.8m/s 1.8-3.3m/s and 3.3-5.4m/s, respectively) during the annual period. Seasonal wind speed distribution results presented very similar pattern of annual distribution. Wind speed distribution of day and night, on the other hand, had a discrepancy with annual modeling results than seasonal distribution in some sections. The results for high wind speed (more than 10.8m/s) showed that this wind blew from the west. This high wind speed is known locally as the 'Shamal', which occurs rarely, lasting one or two days with the strongest winds experienced in association with gust fronts and thunderstorms. Six variations of cesium-137 (137Cs) dispersion test were simulated under hypothetic severe accidental condition. The 137Cs dispersion was strongly influenced by the direction and speed of the main wind. From the test cases, east-south area of the BNPP site was mainly influenced by 137Cs dispersion. A virtual receptor was set and calculated for observation of the 137Cs movement and accumulation. Surface roughness tests were performed for the analysis of topographic conditions. According to the surface condition, there are various surface roughness length. Four types of surface conditions were selected, including city area, hedge area, cut grass, and desert area. Four cases of simulations were performed under the same conditions except for surface the roughness factor. The results indicated that relatively high concentrations were found at the high surface roughness near the origin of the source point. The city area contained approximately four times 137Cs concentration than that of desert area. The atmospheric dispersion of 137Cs was affected by the surface condition in the proximal area. Moreover, movement of the radioactive material had a tendency to be dispersed in a relatively wide range in the desert areas compared to in the higher surface roughness areas. The results of these study offer useful information for developing environmental radiation monitoring systems (ERMSs) and evacuation plan under unexpected emergency condition for the BNPP and can be used to assess the environmental effects of new nuclear power plant. This work was supported by the Nuclear Safety Research Program through the Korea Nuclear Safety Foundation(KORSAFe), granted financial resource from the Nuclear Safety and Security Commission(NSSC), Republic of Korea (No. 1503003).

An analysis of spatial representativeness of air temperature monitoring stations

NASA Astrophysics Data System (ADS)

Liu, Suhua; Su, Hongbo; Tian, Jing; Wang, Weizhen

2018-05-01

Surface air temperature is an essential variable for monitoring the atmosphere, and it is generally acquired at meteorological stations that can provide information about only a small area within an r m radius ( r-neighborhood) of the station, which is called the representable radius. In studies on a local scale, ground-based observations of surface air temperatures obtained from scattered stations are usually interpolated using a variety of methods without ascertaining their effectiveness. Thus, it is necessary to evaluate the spatial representativeness of ground-based observations of surface air temperature before conducting studies on a local scale. The present study used remote sensing data to estimate the spatial distribution of surface air temperature using the advection-energy balance for air temperature (ADEBAT) model. Two target stations in the study area were selected to conduct an analysis of spatial representativeness. The results showed that one station (AWS 7) had a representable radius of about 400 m with a possible error of less than 1 K, while the other station (AWS 16) had the radius of about 250 m. The representable radius was large when the heterogeneity of land cover around the station was small.

Predicting water-surface fluctuation of continental lakes: A RS and GIS based approach in Central Mexico

USGS Publications Warehouse

Mendoza, M.E.; Bocco, G.; Bravo, M.; Lopez, Granados E.; Osterkamp, W.R.

2006-01-01

Changes in the water-surface area occupied by the Cuitzeo Lake, Mexico, during the 1974-2001 period are analysed in this study. The research is based on remote sensing and geographic information techniques, as well as statistical analysis. High-resolution satellite image data were used to analyse the 1974-2000 period, and very low-resolution satellite image data were used for the 1997-2001 period. The long-term analysis (1974-2000) indicated that there were temporal changes in the surface area of the Cuitzeo Lake and that these changes were related to precipitation and temperatures that occurred in the previous year. Short-term monitoring (1997-2001) showed that the Cuitzeo Lake surface is lowering. Field observations demonstrated also that yearly desiccation is recurrent, particularly, in the western section of the lake. Results suggested that this behaviour was probably due to a drought period in the basin that began in the mid 1990s. Regression models constructed from long-term data showed that fluctuations of lake level can be estimated by monthly mean precipitation and temperatures of the previous year. ?? Springer Science + Business Media, Inc. 2006.

Surfactant adsorption and aggregate structure of silica nanoparticles: a versatile stratagem for the regulation of particle size and surface modification

NASA Astrophysics Data System (ADS)

Chaudhary, Savita; Rohilla, Deepak; Mehta, S. K.

2014-03-01

The area of silica nanoparticles is incredibly polygonal. Silica particles have aroused exceptional deliberation in bio-analysis due to great progress in particular arenas, for instance, biocompatibility, unique properties of modifiable pore size and organization, huge facade areas and pore volumes, manageable morphology and amendable surfaces, elevated chemical and thermal stability. Currently, silica nanoparticles participate in crucial utilities in daily trade rationales such as power storage, chemical and genetic sensors, groceries dispensation and catalysis. Herein, the size-dependent interfacial relation of anionic silica nanoparticles with twelve altered categories of cationic surfactants has been carried out in terms of the physical chemical facets of colloid and interface science. The current analysis endeavours to investigate the virtual consequences of different surfactants through the development of the objective composite materials. The nanoparticle size controls, the surface-to-volume ratio and surface bend relating to its interaction with surfactant will also be addressed in this work. More importantly, the simulated stratagem developed in this work can be lengthened to formulate core-shell nanostructures with functional nanoparticles encapsulated in silica particles, making this approach valuable and extensively pertinent for employing sophisticated materials for catalysis and drug delivery.

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.

Investigation of subsidence event over multiple seam mining area

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

Kohli, K.K.

1999-07-01

An investigation was performed to determine the sequence of events which caused the 1987 surface subsidence and related damage to several homes in Walker County, Alabama, USA. Surface affects compared to mine maps indicated the subsidence to be mine related. However, two coal seams had been worked under this area. The upper seam, the American seam, ranged from 250 to 280 feet beneath the surface in the area in question. It was mined-out before 1955 by room-and-pillar method leaving in place narrow-long pillars to support the overburden strata, and abandoned in 1955. The lower seam, the Mary Lee seam, rangedmore » from 650 to 700 feet beneath the surface. The Mary Lee seam had been abandoned in 1966 and subsequently became flooded. The dewatering of the Mary Lee seam workings in 1985 caused the submerged pillars to be exposed to the atmosphere. Due to multiple seam mining and the fact that workings had been inundated then dewatered, a subsurface investigation ensued to determine the sequence and ultimate cause of surface subsidence. Core sample tests with fracture analysis in conjunction with down-the-hole TV camera inspections provided necessary information to determine that the subsidence started in the lower seam and progressed through the upper coal seam to the surface. Evidence from the investigation program established that dewatering of the lower seam workings caused the marginally stable support pillars and the roof to collapse. This failure triggered additional subsidence in the upper seam which broadened the area of influence at the surface.« less

Verification of finite element analysis of fixed partial denture with in vitro electronic strain measurement.

PubMed

Wang, Gaoqi; Zhang, Song; Bian, Cuirong; Kong, Hui

2016-01-01

The purpose of the study was to verify the finite element analysis model of three-unite fixed partial denture with in vitro electronic strain analysis and analyze clinical situation with the verified model. First, strain gauges were attached to the critical areas of a three-unit fixed partial denture. Strain values were measured under 300 N load perpendicular to the occlusal plane. Secondly, a three-dimensional finite element model in accordance with the electronic strain analysis experiment was constructed from the scanning data. And the strain values obtained by finite element analysis and in vitro measurements were compared. Finally, the clinical destruction of the fixed partial denture was evaluated with the verified finite element analysis model. There was a mutual agreement and consistency between the finite element analysis results and experimental data. The finite element analysis revealed that failure will occur in the veneer layer on buccal surface of the connector under occlusal force of 570 N. The results indicate that the electronic strain analysis is an appropriate and cost saving method to verify the finite element model. The veneer layer on buccal surface of the connector is the weakest area in the fixed partial denture. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Fabrication mechanism of friction-induced selective etching on Si(100) surface

PubMed Central

2012-01-01

As a maskless nanofabrication technique, friction-induced selective etching can easily produce nanopatterns on a Si(100) surface. Experimental results indicated that the height of the nanopatterns increased with the KOH etching time, while their width increased with the scratching load. It has also found that a contact pressure of 6.3 GPa is enough to fabricate a mask layer on the Si(100) surface. To understand the mechanism involved, the cross-sectional microstructure of a scratched area was examined, and the mask ability of the tip-disturbed silicon layer was studied. Transmission electron microscope observation and scanning Auger nanoprobe analysis suggested that the scratched area was covered by a thin superficial oxidation layer followed by a thick distorted (amorphous and deformed) layer in the subsurface. After the surface oxidation layer was removed by HF etching, the residual amorphous and deformed silicon layer on the scratched area can still serve as an etching mask in KOH solution. The results may help to develop a low-destructive, low-cost, and flexible nanofabrication technique suitable for machining of micro-mold and prototype fabrication in micro-systems. PMID:22356699

Fabrication mechanism of friction-induced selective etching on Si(100) surface.

PubMed

Guo, Jian; Song, Chenfei; Li, Xiaoying; Yu, Bingjun; Dong, Hanshan; Qian, Linmao; Zhou, Zhongrong

2012-02-23

As a maskless nanofabrication technique, friction-induced selective etching can easily produce nanopatterns on a Si(100) surface. Experimental results indicated that the height of the nanopatterns increased with the KOH etching time, while their width increased with the scratching load. It has also found that a contact pressure of 6.3 GPa is enough to fabricate a mask layer on the Si(100) surface. To understand the mechanism involved, the cross-sectional microstructure of a scratched area was examined, and the mask ability of the tip-disturbed silicon layer was studied. Transmission electron microscope observation and scanning Auger nanoprobe analysis suggested that the scratched area was covered by a thin superficial oxidation layer followed by a thick distorted (amorphous and deformed) layer in the subsurface. After the surface oxidation layer was removed by HF etching, the residual amorphous and deformed silicon layer on the scratched area can still serve as an etching mask in KOH solution. The results may help to develop a low-destructive, low-cost, and flexible nanofabrication technique suitable for machining of micro-mold and prototype fabrication in micro-systems.

Differential processing of binocular and monocular gloss cues in human visual cortex.

PubMed

Sun, Hua-Chun; Di Luca, Massimiliano; Ban, Hiroshi; Muryy, Alexander; Fleming, Roland W; Welchman, Andrew E

2016-06-01

The visual impression of an object's surface reflectance ("gloss") relies on a range of visual cues, both monocular and binocular. Whereas previous imaging work has identified processing within ventral visual areas as important for monocular cues, little is known about cortical areas involved in processing binocular cues. Here, we used human functional MRI (fMRI) to test for brain areas selectively involved in the processing of binocular cues. We manipulated stereoscopic information to create four conditions that differed in their disparity structure and in the impression of surface gloss that they evoked. We performed multivoxel pattern analysis to find areas whose fMRI responses allow classes of stimuli to be distinguished based on their depth structure vs. material appearance. We show that higher dorsal areas play a role in processing binocular gloss information, in addition to known ventral areas involved in material processing, with ventral area lateral occipital responding to both object shape and surface material properties. Moreover, we tested for similarities between the representation of gloss from binocular cues and monocular cues. Specifically, we tested for transfer in the decoding performance of an algorithm trained on glossy vs. matte objects defined by either binocular or by monocular cues. We found transfer effects from monocular to binocular cues in dorsal visual area V3B/kinetic occipital (KO), suggesting a shared representation of the two cues in this area. These results indicate the involvement of mid- to high-level visual circuitry in the estimation of surface material properties, with V3B/KO potentially playing a role in integrating monocular and binocular cues. Copyright © 2016 the American Physiological Society.

Biopolymer protected silver nanoparticles on the support of carbon nanotube as interface for electrocatalytic applications

NASA Astrophysics Data System (ADS)

Satyanarayana, M.; Kumar, V. Sunil; Gobi, K. Vengatajalabathy

2016-04-01

In this research, silver nanoparticles (SNPs) are prepared on the surface of carbon nanotubes via chitosan, a biopolymer linkage. Here chitosan act as stabilizing agent for nanoparticles and forms a network on the surface of carbon nanotubes. Synthesized silver nanoparticles-MWCNT hybrid composite is characterized by UV-Visible spectroscopy, XRD analysis, and FESEM with EDS to evaluate the structural and chemical properties of the nanocomposite. The electrocatalytic activity of the fabricated SNP-MWCNT hybrid modified glassy carbon electrode has been evaluated by cyclic voltammetry and electrochemical impedance analysis. The silver nanoparticles are of size ˜35 nm and are well distributed on the surface of carbon nanotubes with chitosan linkage. The prepared nanocomposite shows efficient electrocatalytic properties with high active surface area and excellent electron transfer behaviour.

Preliminary results of the comparative study between EO-1/Hyperion and ALOS/PALSAR

NASA Astrophysics Data System (ADS)

Koizumi, E.; Furuta, R.; Yamamoto, A.

2011-12-01

[Introduction]Hyper-spectral remote sensing images have been used for land-cover classification due to their high spectral resolutions. Synthetic Aperture Radar (SAR) remote sensing data are also useful to probe surface condition because radar image reflects surface geometry, although there are not so many reports about the land-cover detection with combination use of both hyper-spectral data and SAR data. Among SAR sensors, L-band SAR is thought to be useful tool to find physical properties because its comparatively long wave length can through small objects on surface. We are comparing the result of land cover classification and/or physical values from hyper-spectral and L-band SAR data to find the relationship between these two quite different sensors and to confirm the possibility of the combined analysis of hyper-spectral and L-band SAR data, and in this presentation we will report the preliminary result of this study. There are only few sources of both hyper-spectral and L-band SAR data from the space in this time, however, several space organizations plan to launch new satellites on which hyper-spectral or L-band SAR equipments are mounted in next few years. So, the importance of the combined analysis will increase more than ever. [Target Area]We are performing and planning analyses on the following areas in this study. (a)South of Cairo, Nile river area, Egypt, for sand, sandstone, limestone, river, crops. (b)Mount Sakurajima, Japan, for igneous rock and other related geological property. [Methods and Results]EO-1 Hyperion data are analyzed in this study as hyper-spectral data. The Hyperion equipment has 242 channels but some of them include full noise or have no data. We selected channels for analysis by checking each channel, and select about 150 channels (depend on the area). Before analysis, the atmospheric correction of ATCOR-3 was applied for the selected channels. The corrected data were analyzed by unsupervised classification or principal component analysis (PCA). We also did the unsupervised classification with the several components from PCA. According to the analysis results, several classifications can be extracted for each category (vegetation, sand and rocks, and water). One of the interesting results is that there are a few classes for sand as those of other categories, and these classes seem to reflect artificial and natural surface changes that are some result of excavation or scratching. ALOS PALSAR data are analyzed as L-band SAR data. We selected the Dual Polarization data for each target area. The data were converted to backscattered images, and then calculated some image statistic values. The topographic information also calculates with SAR interferometry technique as reference. Comparing the Hyperion classification results with the result of the calculation of statistic values from PALSAR, there are some areas where relativities seem to be confirmed. To confirm the combined analysis between hyper-spectral and L-band SAR data to detect and classify the surface material, further studies are still required. We will continue to investigate more efficient analytic methods and to examine other functions like the adopted channels, the number of class in classification, the kind of statistic information, and so on, to refine the method.

Adsorption and desorption of carbaryl on hexadecyl trimethyl ammonium bromide modified zeolite NaY using RGB portable photometer

NASA Astrophysics Data System (ADS)

Patdhanagul, Nopbhasinthu; Chanpaka, Saiphon; Intharaksa, Orapan; Sirival, Rujikarn; Thanomsith, Kannikar; Wongkwanklom, Sarayuth

2018-04-01

The carbaryl adsorption-desorption isotherms of zeolite NaY and hexadecyl trimethyl ammonium bromide (HTAB) modified zeolite NaY were investigated. Zeolite NaY was synthesized and modified by HTAB in the concentration range 0.1 - 10.0 mM. The adsorption isotherms indicated that zeolite modified with HTAB could significantly enhance the carbaryl adsorption capacity. Zeolite NaY modified with 5.0 mM HTAB gave great carbaryl adsorption because of hydrophilic surface. The 5.0 mM HTAB could adsorb up to 145.75 ppm g-1 of carbaryl which was equivalent to a 36.7% increase. The Surface area characterization showed the remaining of pore volume and pore size diameter and external surface area whereas the BET surface area and micropore surface area of modified zeolite slightly decreased. The XRD results indicate that modification of zeolite NaY with HTAB does not change the crystallinity of the starting zeolite. The elemental analysis indicated that the Si/Al ratio of synthesized zeolite NaY was close to 2.43. Desorption of carbaryl was tested by organic solvents such as methanol, ethanol, tetrahydrofuran, hexane and Deionized water. The results demonstrated that the percentage desorption of methanol is the highest. Carbaryl was quantitatively desorbed with percentage desorption of 82-100 %. It indicated sorption mechanism of carbaryl on the modified sorbent which was principally driven by hydrophobic forces.

Evaluation of algorithms for point cloud surface reconstruction through the analysis of shape parameters

NASA Astrophysics Data System (ADS)

Cao, Lu; Verbeek, Fons J.

2012-03-01

In computer graphics and visualization, reconstruction of a 3D surface from a point cloud is an important research area. As the surface contains information that can be measured, i.e. expressed in features, the application of surface reconstruction can be potentially important for application in bio-imaging. Opportunities in this application area are the motivation for this study. In the past decade, a number of algorithms for surface reconstruction have been proposed. Generally speaking, these methods can be separated into two categories: i.e., explicit representation and implicit approximation. Most of the aforementioned methods are firmly based in theory; however, so far, no analytical evaluation between these methods has been presented. The straightforward way of evaluation has been by convincing through visual inspection. Through evaluation we search for a method that can precisely preserve the surface characteristics and that is robust in the presence of noise. The outcome will be used to improve reliability in surface reconstruction of biological models. We, therefore, use an analytical approach by selecting features as surface descriptors and measure these features in varying conditions. We selected surface distance, surface area and surface curvature as three major features to compare quality of the surface created by the different algorithms. Our starting point has been ground truth values obtained from analytical shapes such as the sphere and the ellipsoid. In this paper we present four classical surface reconstruction methods from the two categories mentioned above, i.e. the Power Crust, the Robust Cocone, the Fourier-based method and the Poisson reconstruction method. The results obtained from our experiments indicate that Poisson reconstruction method performs the best in the presence of noise.

Large catchment area recharges Titan's Ontario Lacus

NASA Astrophysics Data System (ADS)

Dhingra, Rajani D.; Barnes, Jason W.; Yanites, Brian J.; Kirk, Randolph L.

2018-01-01

We seek to address the question of what processes are at work to fill Ontario Lacus while other, deeper south polar basins remain empty. Our hydrological analysis indicates that Ontario Lacus has a catchment area spanning 5.5% of Titan's surface and a large catchment area to lake surface area ratio. This large catchment area translates into large volumes of liquid making their way to Ontario Lacus after rainfall. The areal extent of the catchment extends to at least southern mid-latitudes (40°S). Mass conservation calculations indicate that runoff alone might completely fill Ontario Lacus within less than half a Titan year (1 Titan year = 29.5 Earth years) assuming no infiltration. Cassini Visual and Infrared Mapping Spectrometer (VIMS) observations of clouds over the southern mid and high-latitudes are consistent with precipitation feeding Ontario's large catchment area. This far-flung rain may be keeping Ontario Lacus filled, making it a liquid hydrocarbon oasis in the relatively dry south polar region.

Complex interaction of subsequent surface streamers via deposited charge: a high-resolution experimental study

NASA Astrophysics Data System (ADS)

Hoder, T.; Synek, P.; Chorvát, D.; Ráhel', J.; Brandenburg, R.; Černák, M.

2017-07-01

The coplanar barrier discharge in synthetic air at 30 kPa pressure was studied by time-correlated single photon counting enhanced optical emission spectroscopy, far-field microscopy enhanced intensified CCD camera and sensitive current measurements. The discharge operated in a regime where two subsequent microdischarges appeared within the same voltage half-period. The electrical analysis of the barrier discharge setup enabled us to quantify charge transfer and the effective electric field development. During the second microdischarge the positive surface streamers follow the interface (triple-line) between the area of deposited charge from the previous one and the area of uncharged dielectric surface. It is shown that additional branching and flashes of surface streamers are responsible for the increased spatial complexity of the deposited surface charges at high overvoltage. A suppressed streamer propagating over the area of deposited surface charge was tracked and the evidence of surface streamer reconnection is presented. A spatiotemporal distribution (resolution of 120 ps and 100 μm) of the reduced electric field strength was obtained for both microdischarges from the recorded luminosities of the molecular nitrogen. The reduced electric field of positive streamers in the first microdischarge reached 1200 Td. For the second one, the electric field values for the streamer at the triple-line are slightly lower than that, while for the suppressed streamers are even higher.

[Applications of 2D and 3D landscape pattern indices in landscape pattern analysis of mountainous area at county level].

PubMed

Lu, Chao; Qi, Wei; Li, Le; Sun, Yao; Qin, Tian-Tian; Wang, Na-Na

2012-05-01

Landscape pattern indices are the commonly used tools for the quantitative analysis of landscape pattern. However, the traditional 2D landscape pattern indices neglect the effects of terrain on landscape, existing definite limitations in quantitatively describing the landscape patterns in mountains areas. Taking the Qixia City, a typical mountainous and hilly region in Shandong Province of East China, as a case, this paper compared the differences between 2D and 3D landscape pattern indices in quantitatively describing the landscape patterns and their dynamic changes in mountainous areas. On the basis of terrain structure analysis, a set of landscape pattern indices were selected, including area and density (class area and mean patch size), edge and shape (edge density, landscape shape index, and fractal dimension of mean patch), diversity (Shannon's diversity index and evenness index) , and gathering and spread (contagion index). There existed obvious differences between the 3D class area, mean patch area, and edge density and the corresponding 2D indices, but no significant differences between the 3D landscape shape index, fractal dimension of mean patch, and Shannon' s diversity index and evenness index and the corresponding 2D indices. The 3D contagion index and 2D contagion index had no difference. Because the 3D landscape pattern indices were calculated by using patch surface area and surface perimeter whereas the 2D landscape pattern indices were calculated by adopting patch projective area and projective perimeter, the 3D landscape pattern indices could be relative accurate and efficient in describing the landscape area, density and borderline, in mountainous areas. However, there were no distinct differences in describing landscape shape, diversity, and gathering and spread between the 3D and 2D landscape pattern indices. Generally, by introducing 3D landscape pattern indices to topographic pattern, the description of landscape pattern and its dynamic change would be relatively accurate.

Characterization of the adsorption of water vapor and chlorine on microcrystalline silica

NASA Technical Reports Server (NTRS)

Skiles, J. A.; Wightman, J. P.

1979-01-01

The characterization of water adsorption on silica is necessary to an understanding of how hydrogen chloride interacts with silica. The adsorption as a function of outgas temperatures of silica and as a function of the isotherm temperature was studied. Characterization of the silica structure by infrared analysis, X-ray diffraction and differential scanning calorimetry, surface area determinations, characterization of the sample surface by electron spectroscopy for chemical analysis (ESCA), and determinations of the heat of immersion in water of silica were investigated. The silica with a scanning electron microscope was examined.

Profiled Roller Stress/Fatigue Life Analysis Methodology and Establishment of an Appropriate Stress/Life Exponent

NASA Technical Reports Server (NTRS)

1997-01-01

The objective of this work was to determine the three dimensional volumetric stress field, surface pressure distribution and actual contact area between a 0.50" square roller with different crown profiles and a flat raceway surface using Finite Element Analysis. The 3-dimensional stress field data was used in conjunction with several bearing fatigue life theories to extract appropriate values for stress-life exponents. Also, results of the FEA runs were used to evaluate the laminated roller model presently used for stress and life prediction.

Investigating the role of the land surface in explaining the interannual variation of the net radiation balance over the Western Sahara and sub-Sahara

NASA Technical Reports Server (NTRS)

Smith, Eric A.; Nicholson, Sharon

1987-01-01

The status of the data sets is discussed. Progress was made in both data analysis and modeling areas. The atmospheric and land surface contributions to the net radiation budget over the Sahara-Sahel region is being decoupled. The interannual variability of these two processes was investigated and this variability related to seasonal rainfall fluctuations. A modified Barnes objective analysis scheme was developed which uses an eliptic scan pattern and a 3-pass iteration of the difference fields.

Analysis of scattering behavior and radar penetration in AIRSAR data

NASA Technical Reports Server (NTRS)

Rignot, Eric; Van Zyl, Jakob

1992-01-01

A technique is presented to physically characterize changes in radar backscatter with frequency in multifrequency single polarization radar images that can be used as a first step in the analysis of the data and the retrieval of geophysical parameters. The technique is automatic, relatively independent of the incidence angle, and only requires a good calibration accuracy between the different frequencies. The technique reveals large areas where scattering changes significantly with frequency and whether the surface has the characteristics of a smooth, slightly rough, rough, or very rough surface.

Field Sampling Plan/Quality Assurance Project Plan Volume I of III

EPA Pesticide Factsheets

This document contains procedures related to the collection and analysis of soil, sediment, groundwater, surface water, air and biota samples at GE’s Pittsfield, Massachusetts facility and at other areas.

Heavy metal contamination of surface soil in electronic waste dismantling area: site investigation and source-apportionment analysis.

PubMed

Jinhui Li; Huabo Duan; Pixing Shi

2011-07-01

The dismantling and disposal of electronic waste (e-waste) in developing countries is causing increasing concern because of its impacts on the environment and risks to human health. Heavy-metal concentrations in the surface soils of Guiyu (Guangdong Province, China) were monitored to determine the status of heavy-metal contamination on e-waste dismantling area with a more than 20 years history. Two metalloids and nine metals were selected for investigation. This paper also attempts to compare the data among a variety of e-waste dismantling areas, after reviewing a number of heavy-metal contamination-related studies in such areas in China over the past decade. In addition, source apportionment of heavy metal in the surface soil of these areas has been analysed. Both the MSW open-burning sites probably contained invaluable e-waste and abandoned sites formerly involved in informal recycling activities are the new sources of soil-based environmental pollution in Guiyu. Although printed circuit board waste is thought to be the main source of heavy-metal emissions during e-waste processing, requirement is necessary to soundly manage the plastic separated from e-waste, which mostly contains heavy metals and other toxic substances.

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.

Surface deformation monitoring of Sinabung volcano using multi temporal InSAR method and GIS analysis for affected area assessment

NASA Astrophysics Data System (ADS)

Aditiya, A.; Aoki, Y.; Anugrah, R. D.

2018-04-01

Sinabung Volcano which located in northern part of Sumatera island is part of a hundred active volcano in Indonesia. Surface deformation is detected over Sinabung Volcano and surrounded area since the first eruption in 2010 after 400 years long rest. We present multi temporal Interferometric Synthetic Aperture Radar (InSAR) time-series method of ALOS-2 L-band SAR data acquired from December 2014 to July 2017 to reveal surface deformation with high spatial resolution. The method includes focusing the SAR data, generating interferogram and phase unwrapping using SNAPHU tools. The result reveal significant deformation over Sinabung Volcano areas at rates up to 10 cm during observation period and the highest deformation occurs in western part which is trajectory of lava. We concluded the observed deformation primarily caused by volcanic activity respectively after long period of rest. In addition, Geographic Information System (GIS) analysis produces disaster affected areas of Sinabung eruption. GIS is reliable technique to estimate the impact of the hazard scenario to the exposure data and develop scenarios of disaster impacts to inform their contingency and emergency plan. The GIS results include the estimated affected area divided into 3 zones based on pyroclastic lava flow and pyroclastic fall (incandescent rock and ash). The highest impact is occurred in zone II due to many settlements are scattered in this zone. This information will be support stakeholders to take emergency preparation for disaster reduction. The continuation of this high rate of decline tends to endanger the population in next periods.

A fast and reliable readout method for quantitative analysis of surface-enhanced Raman scattering nanoprobes on chip surface

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

Chang, Hyejin; Jeong, Sinyoung; Ko, Eunbyeol

2015-05-15

Surface-enhanced Raman scattering techniques have been widely used for bioanalysis due to its high sensitivity and multiplex capacity. However, the point-scanning method using a micro-Raman system, which is the most common method in the literature, has a disadvantage of extremely long measurement time for on-chip immunoassay adopting a large chip area of approximately 1-mm scale and confocal beam point of ca. 1-μm size. Alternative methods such as sampled spot scan with high confocality and large-area scan method with enlarged field of view and low confocality have been utilized in order to minimize the measurement time practically. In this study, wemore » analyzed the two methods in respect of signal-to-noise ratio and sampling-led signal fluctuations to obtain insights into a fast and reliable readout strategy. On this basis, we proposed a methodology for fast and reliable quantitative measurement of the whole chip area. The proposed method adopted a raster scan covering a full area of 100 μm × 100 μm region as a proof-of-concept experiment while accumulating signals in the CCD detector for single spectrum per frame. One single scan with 10 s over 100 μm × 100 μm area yielded much higher sensitivity compared to sampled spot scanning measurements and no signal fluctuations attributed to sampled spot scan. This readout method is able to serve as one of key technologies that will bring quantitative multiplexed detection and analysis into practice.« less

Multipolarization P-, L-, and C-band radar for coastal zone mapping - The Louisiana example

NASA Technical Reports Server (NTRS)

Wu, Shih-Tseng

1989-01-01

Multipolarization P-, L-, and C-band airborne SAR data sets were acquired over a coastal zone and a forested wetland of southern Louisiana. The data sets were used with field-collected surface-parameter data in order to determine the value of SAR systems in assessing and mapping coastal-zone surface features. The coastal-zone surface features in this study are sediments, sediment distribution, and the formation of new isles and banks. Results of the data analysis indicate that the P-band radar with 68-cm wavelength is capable of detecting the submerged sediment if the area is very shallow (i.e., a water depth of less than one meter). The penetration capability of P-band radar is also demonstrated in the forested wetland area. The composition and condition of the ground surface can be detected, as well as the standing water beneath dense tree leaves.

Adsorption of cadmium by activated carbon cloth: influence of surface oxidation and solution pH.

PubMed

Rangel-Mendez, J R; Streat, M

2002-03-01

The surface of activated carbon cloth (ACC), based on polyacrylonitrile fibre as a precursor, was oxidised using nitric acid, ozone and electrochemical oxidation to enhance cadmium ion exchange capacity. Modified adsorbents were physically and chemically characterised by pH titration, direct titration, X-ray photoelectron spectroscopy, elemental analysis, surface area and porosimetry, and scanning electron microscopy. BET surface area decreased after oxidation, however, the total ion exchange capacity increased by a factor of approximately 3.5 compared to the commercial as-received ACC. A very significant increase in cadmium uptake, by a factor of 13, was observed for the electrochemically oxidised ACC. Equilibrium sorption isotherms were determined at pH 4, 5 and 6 and these showed that cadmium uptake increased with increasing pH. There was clear evidence of physical damage to ozone-oxidised fibre, however, acid and electrochemically oxidised samples were completely stable.

The production of premixed flame surface area in turbulent shear flow

NASA Technical Reports Server (NTRS)

Trouve, A.

1993-01-01

In the present work, we use three-dimensional Direct Numerical Simulation (DNS) of premixed flames in turbulent shear flow to characterize the effect of a mean shear motion on flame surface production. The shear is uniform in the unburnt gas, and simulations are performed for different values of the mean shear rate, S. The data base is then used to estimate and compare the different terms appearing in the Sigma-equation as a function of S. The analysis gives in particular the relative weights f the turbulent flow and mean flow components, a(sub T) and A(sub T), of the flame surface production term. This comparison indicates whether the dominant effects of a mean flow velocity gradient on flame surface area are implicit and scale with the modified turbulent flow parameters, kappa and epsilon, or explicit and scale directly with the rate of deformation.

Synthesis of porous nanocrystalline NiO with hexagonal sheet-like morphology by homogeneous precipitation method

NASA Astrophysics Data System (ADS)

Sharma, Ravi Kant; Ghose, Ranjana

2015-04-01

Porous nanocrystalline NiO has been synthesized by a simple homogeneous precipitation method in short time at low calcination temperature without using any surfactant, chelating or gelating agents. The porous nanocrystalline NiO with a hexagonal sheet-like morphology were obtained by calcination of Ni(OH)2 nanoflakes at 500 °C. The calcination temperature strongly influences the morphology, crystallite size, specific surface area, pore volume and optical band gap of the samples. The samples were characterized using powder X-ray diffraction, thermal gravimetric analysis, FT-IR spectroscopy, UV-Visible diffuse reflectance spectroscopy, surface area measurements, field emission scanning electron microscopy coupled with energy dispersive X-ray analysis and transmission electron microscopy. The chemical activity of the samples was tested by catalytic reduction of 4-nitrophenol with NaBH4.

The digestive adaptation of flying vertebrates: high intestinal paracellular absorption compensates for smaller guts.

PubMed

Caviedes-Vidal, Enrique; McWhorter, Todd J; Lavin, Shana R; Chediack, Juan G; Tracy, Christopher R; Karasov, William H

2007-11-27

Anecdotal evidence suggests that birds have smaller intestines than mammals. In the present analysis, we show that small birds and bats have significantly shorter small intestines and less small intestine nominal (smooth bore tube) surface area than similarly sized nonflying mammals. The corresponding >50% reduction in intestinal volume and hence mass of digesta carried is advantageous because the energetic costs of flight increase with load carried. But, a central dilemma is how birds and bats satisfy relatively high energy needs with less absorptive surface area. Here, we further show that an enhanced paracellular pathway for intestinal absorption of water-soluble nutrients such as glucose and amino acids may compensate for reduced small intestines in volant vertebrates. The evidence is that l-rhamnose and other similarly sized, metabolically inert, nonactively transported monosaccharides are absorbed significantly more in small birds and bats than in nonflying mammals. To broaden our comparison and test the veracity of our finding we surveyed the literature for other similar studies of paracellular absorption. The patterns found in our focal species held up when we included other species surveyed in our analysis. Significantly greater amplification of digestive surface area by villi in small birds, also uncovered by our analysis, may provide one mechanistic explanation for the observation of higher paracellular absorption relative to nonflying mammals. It appears that reduced intestinal size and relatively enhanced intestinal paracellular absorption can be added to the suite of adaptations that have evolved in actively flying vertebrates.

[Efficient Pharmaceutical Formulation Designs and Their Development Using Mathematical and Statistical Analysis].

PubMed

Iwao, Yasunori

2015-01-01

With the aim of directly predicting the functionality and mechanism of pharmaceutical excipients, we investigated an analysis method based on available surface area (S(t)), which is the surface area of a drug in direct contact with the external solvent during dissolution. First, to study the effect of lubricant concentration on the dissolution rate of acetaminophen (APAP), the dissolution behaviors as well as the change over time in S(t) of APAP tablets were examined. In the dissolution tests, a retarded dissolution of APAP was not observed with new lubricant triglycerin full behenate (TR-FB), whereas magnesium stearate (Mg-St) retarded the dissolution. The S(t) profiles for APAP with Mg-St at>0.5% showed downward curvature indicating a gradual decrease in surface area over time. Conversely, with TR-FB, even when its concentration was increased, the S(t) profile for APAP had a maximum value. The differences between Mg-St and TR-FB could be explained by the differences in extensibility deriving from their morphology. Next, we evaluated the effect of disintegtant concentration using five disintegrants. When disintegrant was added to ethenzamide tablet formulation, an increase in the dissolution rate and S(t) dependent on disintegrant concentration was observed, according to the type of disintegrant. It was found that the water absorption ability of disintegrants had strong correlations with the parameters of S(t). Taken together, this study demonstrates that analysis of S(t) can directly provide useful information, especially about the functionality of pharmaceutical excipients.

Digital data base application to porphyry copper mineralization in Alaska; case study summary

USGS Publications Warehouse

Trautwein, Charles M.; Greenlee, David D.; Orr, Donald G.

1982-01-01

The purpose of this report is to summarize the progress in use of digital image analysis techniques in developing a conceptual model for assessing porphyry copper mineral potential. The study area consists of approximately the southern one-half of the 1? by 3? Nabesna quadrangle in east-central Alaska. The digital geologic data base consists of data compiled under the Alaskan Mineral Resource Assessment Program (AMRAP) as well as digital elevation data and Landsat spectral reflectance data from the Multispectral Scanner System. The digital data base used to develop and implement a conceptual model for porphyry-type copper mineralization consisted of 16 original data types and 18 derived data sets formatted in a grid-cell (raster) structure and registered to a map base in the Universal Transverse Mercator (UTM) projection. Minimum curvature and inverse distance squared interpolation techniques were used to generate continuous surfaces from sets of irregularly spaced data points. Processing requirements included: (1) merging or overlaying of data sets, (2) display and color coding of maps and images, (3) univariate and multivariate statistical analyses, and (4) compound overlaying operations. Data sets were merged and processed to create stereoscopic displays of continuous surfaces. The ratio of several data sets were calculated to evaluate relative variations and to enhance the display of surface alteration (gossans). Factor analysis and principal components analysis techniques were used to determine complex relationships and correlations between data sets. The resultant model consists of 10 parameters that identify three areas most likely to contain porphyry copper mineralization; two of these areas are known occurrences of mineralization and the third is not well known. Field studies confirmed that the three areas identified by the model have significant copper potential.

Analysis of water-surface profiles in Leon County and the city of Tallahassee, Florida

USGS Publications Warehouse

Franklin, M.A.; Orr, R.A.

1987-01-01

Water surface profiles for the 10-, 25-, 50-, and 100-yr recurrence interval floods for most of the streams that drain developing areas of Leon County and the city of Tallahassee are presented. The principal streams studied are in the Lake Munson, Lake Lafayette, and Lake Jackson basins Peak discharges were computed from regression equations based on information gained from 15 streamflow stations in the area. Standard step-backwater procedures were used to determine the water-surface elevations for the streams. The flood elevations were generally higher than those in the Flood Insurance Studies for Tallahassee (1976) and Leon County (1982). The primary reason for the higher profiles is that peak discharges used in this report are larger than those used previously, largely due to changes in land use. The flood profiles for Bradford Brook, North Branch Gum Creek, and West Branch Gum Creek generally match those in the Leon County Flood Insurance Studies. Channel improvements in some areas would lower the flood elevation in that area, but would probably increase flooding downstream. (Lantz-PTT)

Coastal surface sediment quality assessment in Leizhou Peninsula (South China Sea) based on SEM-AVS analysis.

PubMed

Li, Feng; Lin, Jin-qin; Liang, Yan-yan; Gan, Hua-yang; Zeng, Xiang-yun; Duan, Zhi-peng; Liang, Kai; Liu, Xing; Huo, Zhen-hai; Wu, Chang-hua

2014-07-15

Surface sediments from the coastal area of the Leizhou Peninsula in the South China Sea were collected and analyzed and the potential ecological risks in the area were assessed based on acid-volatile sulfide (AVS) model. The AVS levels are between 0.109 and 55.6 μmol g(-1), with the average at 4.45 μmol g(-1). The high AVS-concentration zones include the aquaculture areas of Liusha Bay and the densely populated areas of Zhanjiang Bay. The simultaneously extracted metals (SEM) range from 0.026 μmol g(-1) to 8.61 μmol g(-1), with the average at 0.843 μmol g(-1). Most of high SEM-concentration stations were located in ports or aquaculture zones. Most of the coastal surface sediments of the Leizhou Peninsula (90%) had no adverse biological effects according to the criterion proposed by USEPA (2005); while adverse effects were uncertain in some stations (8%); even in 2 stations (2%) adverse biological effects may be expected. Copyright © 2014 Elsevier Ltd. All rights reserved.

New methods for image collection and analysis in scanning Auger microscopy

NASA Technical Reports Server (NTRS)

Browning, R.

1985-01-01

While scanning Auger micrographs are used extensively for illustrating the stoichiometry of complex surfaces and for indicating areas of interest for fine point Auger spectroscopy, there are many problems in the quantification and analysis of Auger images. These problems include multiple contrast mechanisms and the lack of meaningful relationships with other Auger data. Collection of multielemental Auger images allows some new approaches to image analysis and presentation. Information about the distribution and quantity of elemental combinations at a surface are retrievable, and particular combinations of elements can be imaged, such as alloy phases. Results from the precipitate hardened alloy Al-2124 illustrate multispectral Auger imaging.

Effect of electrode contact area on the information content of the recorded electrogastrograms: An analysis based on Rényi entropy and Teager-Kaiser Energy

NASA Astrophysics Data System (ADS)

Alagumariappan, Paramasivam; Krishnamurthy, Kamalanand; Kandiah, Sundravadivelu; Ponnuswamy, Mannar Jawahar

2017-06-01

Electrogastrograms (EGG) are electrical signals originating from the digestive system, which are closely correlated with its mechanical activity. Electrogastrography is an efficient non-invasive method for examining the physiological and pathological states of the human digestive system. There are several factors such as fat conductivity, abdominal thickness, change in electrode surface area etc, which affects the quality of the recorded EGG signals. In this work, the effect of variations in the contact area of surface electrodes on the information content of the measured electrogastrograms is analyzed using Rényi entropy and Teager-Kaiser Energy (TKE). Two different circular cutaneous electrodes with approximate contact areas of 201.14 mm2 and 283.64 mm2, have been adopted and EGG signals were acquired using the standard three electrode protocol. Further, the information content of the measured EGG signals were analyzed using the computed values of entropy and energy. Results demonstrate that the information content of the measured EGG signals increases by 6.72% for an increase in the contact area of the surface electrode by 29.09%. Further, it was observed that the average energy increases with increase in the contact surface area. This work appears to be of high clinical significance since the accurate measurement of EGG signals without loss in its information content, is highly useful for the design of diagnostic assistance tools for automated diagnosis and mass screening of digestive disorders.

Relationship Between Landcover Pattern and Surface Net Radiation in AN Coastal City

NASA Astrophysics Data System (ADS)

Zhao, X.; Liu, L.; Liu, X.; Zhao, Y.

2016-06-01

Taking Xiamen city as the study area this research first retrieved surface net radiation using meteorological data and Landsat 5 TM images of the four seasons in the year 2009. Meanwhile the 65 different landscape metrics of each analysis unit were acquired using landscape analysis method. Then the most effective landscape metrics affecting surface net radiation were determined by correlation analysis, partial correlation analysis, stepwise regression method, etc. At both class and landscape levels, this paper comprehensively analyzed the temporal and spatial variations of the surface net radiation as well as the effects of land cover pattern on it in Xiamen from a multi-seasonal perspective. The results showed that the spatial composition of land cover pattern shows significant influence on surface net radiation while the spatial allocation of land cover pattern does not. The proportions of bare land and forest land are effective and important factors which affect the changes of surface net radiation all the year round. Moreover, the proportion of forest land is more capable for explaining surface net radiation than the proportion of bare land. So the proportion of forest land is the most important and continuously effective factor which affects and explains the cross-seasonal differences of surface net radiation. This study is helpful in exploring the formation and evolution mechanism of urban heat island. It also gave theoretical hints and realistic guidance for urban planning and sustainable development.

Use of a Sampling Area-Adjusted Adenosine Triphosphate Bioluminescence Assay Based on Digital Image Quantification to Assess the Cleanliness of Hospital Surfaces.

PubMed

Ho, Yu-Huai; Wang, Lih-Shinn; Jiang, Hui-Li; Chang, Chih-Hui; Hsieh, Chia-Jung; Chang, Dan-Chi; Tu, Hsin-Yu; Chiu, Tan-Yun; Chao, Huei-Jen; Tseng, Chun-Chieh

2016-06-09

Contaminated surfaces play an important role in the transmission of pathogens. We sought to establish a criterion that could indicate "cleanliness" using a sampling area-adjusted adenosine triphosphate (ATP) assay. In the first phase of the study, target surfaces were selected for swab sampling before and after daily cleaning; then, an aerobic colony count (ACC) plate assay of bacteria and antibiotic-resistant bacteria was conducted. ATP swabs were also tested, and the ATP readings were reported as relative light units (RLUs). The results of the ACC and ATP assays were adjusted according to the sampling area. During the second phase of the study, a new cleaning process employing sodium dichloroisocyanurate (NaDCC) was implemented for comparison. Using the criterion of 2.5 colony-forming units (CFU)/cm², 45% of the sampled sites were successfully cleaned during phase one of the study. During phase two, the pass rates of the surface samples (64%) were significantly improved, except under stringent (5 RLU/cm²) and lax (500 RLU) ATP criteria. Using receiver-operating characteristic curve analysis, the best cut-off point for an area-adjusted ATP level was 7.34 RLU/cm², which corresponded to culture-assay levels of <2.5 CFU/cm². An area adjustment of the ATP assay improved the degree of correlation with the ACC-assay results from weak to moderate.

A Mass Computation Model for Lightweight Brayton Cycle Regenerator Heat Exchangers

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.

2010-01-01

Based on a theoretical analysis of convective heat transfer across large internal surface areas, this paper discusses the design implications for generating lightweight gas-gas heat exchanger designs by packaging such areas into compact three-dimensional shapes. Allowances are made for hot and cold inlet and outlet headers for assembly of completed regenerator (or recuperator) heat exchanger units into closed cycle gas turbine flow ducting. Surface area and resulting volume and mass requirements are computed for a range of heat exchanger effectiveness values and internal heat transfer coefficients. Benefit cost curves show the effect of increasing heat exchanger effectiveness on Brayton cycle thermodynamic efficiency on the plus side, while also illustrating the cost in heat exchanger required surface area, volume, and mass requirements as effectiveness is increased. The equations derived for counterflow and crossflow configurations show that as effectiveness values approach unity, or 100 percent, the required surface area, and hence heat exchanger volume and mass tend toward infinity, since the implication is that heat is transferred at a zero temperature difference. To verify the dimensional accuracy of the regenerator mass computational procedure, calculation of a regenerator specific mass, that is, heat exchanger weight per unit working fluid mass flow, is performed in both English and SI units. Identical numerical values for the specific mass parameter, whether expressed in lb/(lb/sec) or kg/(kg/sec), show the dimensional consistency of overall results.

A Mass Computation Model for Lightweight Brayton Cycle Regenerator Heat Exchangers

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.

2010-01-01

Based on a theoretical analysis of convective heat transfer across large internal surface areas, this paper discusses the design implications for generating lightweight gas-gas heat exchanger designs by packaging such areas into compact three-dimensional shapes. Allowances are made for hot and cold inlet and outlet headers for assembly of completed regenerator (or recuperator) heat exchanger units into closed cycle gas turbine flow ducting. Surface area and resulting volume and mass requirements are computed for a range of heat exchanger effectiveness values and internal heat transfer coefficients. Benefit cost curves show the effect of increasing heat exchanger effectiveness on Brayton cycle thermodynamic efficiency on the plus side, while also illustrating the cost in heat exchanger required surface area, volume, and mass requirements as effectiveness is increased. The equations derived for counterflow and crossflow configurations show that as effectiveness values approach unity, or 100 percent, the required surface area, and hence heat exchanger volume and mass tend toward infinity, since the implication is that heat is transferred at a zero temperature difference. To verify the dimensional accuracy of the regenerator mass computational procedure, calculation of a regenerator specific mass, that is, heat exchanger weight per unit working fluid mass flow, is performed in both English and SI units. Identical numerical values for the specific mass parameter, whether expressed in lb/(lb/sec) or kg/ (kg/sec), show the dimensional consistency of overall results.

Związek rozmieszczenia powierzchniowych form krasowych międzyrzecza środkowego Wieprza i Bugu z tektoniką dysjunktywną w świetle analizy statystycznej

NASA Astrophysics Data System (ADS)

Kamińska, Anna

2010-01-01

The relationship between karst of chalk and tectonics in the interfluve of the middle Wieprz and Bug Rivers has been already examined by Maruszczak (1966), Harasimiuk (1980) and Dobrowolski (1998). Investigating the connection of the karst formation course and the substratum structure, the direction of the landforms and their spatial pattern were analysed and compared later to the structural pattern. The obvious completion of the collected data is a quantity analysis using statistical methods. This paper deals with the characteristics of such quantity analysis. By using the tools of the directional statistics, the following indexes have been calculated: the mean vector orientation, the length of the vector mean, strength of the vector mean, the Batschelet variance, as well as determined confidence intervals for the mean vector. In order to examine the distribution structure of these forms, the selected methods of the spatial statistics have been used-angular wavelet analysis (Rosenberg 2004) and the semivariogram analysis (Namysłowska-Wilczyńska 2006). On the basis of conducted analyses, it is possible to describe in detail the regularities in spatial distribution of the surface karst forms in the interfluve of the middle Wieprz and Bug Rivers. The orientation analysis reveals an important feature of their direction-along with a rise in the size of surface karst forms, the level of concentration around the mean vector orientation increases. Primary karst forms point out poor concentration along the longitudinal direction whereas complex forms are clearly concentrated along the WNW-ESE direction. Hence, only after clumping of the primary forms into the complex ones, the convergence of the surface karst forms direction with the direction of the main faults in the Meso-Cenozoic complex is visible (after A. Henkiel 1984). The results of the wavelet analysis modified by Rosenberg (2004) have indicated significant directions of the clumping of the surface karst forms. A clear difference in the distribution of these forms in west and east areas is noticed. Whereas the west area is dominated by the W-E, NW-SE, N-S directions, the karst forms in the east are concentrated along the NE-SW direction. The semivariogram analysis has confirmed the importance of the W-E and NE-SW directions. Moreover, this analysis has indicated which areas are characterized by the poor karst forms direction. It is a region where the Kock-Wasylów dislocation zone crosses the Święcica dislocation zone in the north-east part of the analysed area. The south-east region is the second such area. The picture of the spatial pattern one confirms the previous results (Dobrowolski 1998) and refers clearly to the structural pattern of this area. Nevertheless, the analyses mentioned above have shown the dominance of the W-E direction over the NW-SE one. The obtained results of the spatial and direction analyses expand and confirm hitherto information about the relation between the spatial pattern of the karst landforms and the tectonics in the interfluve of the middle Wieprz and Bug Rivers.

Medicine Delivery Device with Integrated Sterilization and Detection

NASA Technical Reports Server (NTRS)

Shearn, Michael J.; Greer, Harold F.; Manohara, Harish

2013-01-01

Sterile delivery devices can be created by integrating a medicine delivery instrument with surfaces that are coated with germicidal and anti-fouling material. This requires that a large-surface-area template be developed within a constrained volume to ensure good contact between the delivered medicine and the germicidal material. Both of these can be integrated using JPL-developed silicon nanotip or cryo-etch black silicon technologies with atomic layer deposition (ALD) coating of specific germicidal layers. The application of semiconductor processing techniques and technologies to the problems of fluid manipulation and delivery has enabled the integration of chemical, electrical, and mechanical manipulation of samples all within a single microfluidic device. This approach has been successfully applied at JPL to the automated processing, detection, and analysis of minute quantities (parts per trillion level) of biomaterials to develop instruments for in situ exploration or extraterrestrial bodies. The same nanofabrication techniques that are used to produce a microfluidics device are also capable of synthesizing extremely high-surface-area templates in precise locations, and coating those surfaces with conformal films to manipulate their surface properties. This methodology has been successfully applied at JPL to produce patterned and coated silicon nanotips (also known as black silicon) to manipulate the hydrophilicity of surfaces to direct the spreading of fluids in microdevices. JPL's ALD technique is an ideal method to produce the highly conformal coatings required for this type of application. Certain materials, such as TiO2, have germicidal and anti-fouling properties when they are illuminated with UV light. The proposed delivery device contacts medicine with this high-surface-area black silicon surface coated with a thin-film germicidal deposited conformally with ALD. The coating can also be illuminated with ultraviolet light for the purpose of sterilization or identification of the medicine itself. This constrained volume that is located immediately prior to delivery into a patient, ensures that the medicine delivery device is inherently sterile. An additional benefit to integrating a high-surface-area template within the fluid channel of a medicine delivery device is that one can envision a number of different functional coatings that could facilitate the capture and analysis of either microbial contaminants or the medicine itself. For example, one could attach antibodies or some other binding agent with a specific affinity to the silicon nanotip template. Once a target molecule or microbe is bound to the high-surface- area template, one could use an optical analytical technique such as fluorescence or adsorption to determine the identity and potentially the concentration of the species of interest. By illuminating the bound species from the back, it may also be possible to probe only the molecules with an evanescent wave, making detection of the species from the front side of the device much simpler.

Changing Surface-Atmosphere Energy Exchange and Refreezing Capacity of the Lower Accumulation Area, West Greenland

NASA Astrophysics Data System (ADS)

Charalampidis, C.; van As, D.; Machguth, H.; Smeets, P.; van den Broeke, M. R.; Box, J. E.

2014-12-01

We present five years (2009-2013) of automatic weather station (AWS) data from the lower accumulation area (1840 m above sea level) of the Kangerlussuaq region, western Greenland ice sheet. The summers of 2010 and 2012 were both exceptionally warm, but only 2012 resulted in negative surface mass budget (SMB) and surface runoff. The observed runoff was due to a large ice fraction in the upper 10 m of firn that prevented melt water from percolating to available pore space below. Analysis of the in situ data reveals a relatively low 2012 summer albedo of ~0.7 as melt water was present at the surface. Consequently, during the 2012 melt season the surface absorbed 30% (213 MJ m-2) more solar radiation than in 2010. We drive a surface energy balance model with the AWS data to evaluate the seasonal and interannual variability of all surface energy fluxes. The model is able to reproduce the observed melt rates as well as the SMB for each season. While the drive for melt is solar radiation, year-to-year differences are controlled by terrestrial radiation, apart from 2012 when solar radiation dominated melt. Sensitivity tests reveal that 72% of the excess solar energy in 2012 was used for melt, corresponding to 40% (0.67 m) of the 2012 surface ablation. The remaining ablation (0.99 m) was primarily due to the relatively high atmospheric temperatures up to +2.6 °C daily average, indicating that 2012 would have been a negative SMB year in the lower accumulation area even without the melt-albedo feedback. Longer time series of SMB, regional temperature and remotely sensed albedo (MODIS) suggest that 2012 was the first negative SMB year with the lowest albedo at this elevation on record. The warming conditions of the last years resulted in enhanced melt and reduction of the refreezing capacity of the lower accumulation area. If the warming continues the lower accumulation area will be transformed into superimposed ice.

Variations of surface ozone concentration across the Klang Valley, Malaysia

NASA Astrophysics Data System (ADS)

Latif, Mohd Talib; Huey, Lim Shun; Juneng, Liew

2012-12-01

Hourly air quality data covering the period 2004-2008 was obtained from the Air Quality Division, the Department of Environment (DOE) through long-term monitoring by Alam Sekitar Sdn. Bhd. (ASMA) were analysed to investigate the variations of surface ozone (O3) in the Klang Valley, Malaysia. A total of nine monitoring stations were selected for analysis in this study and the results show that there are distinct seasonal patterns in the surface O3 across the Klang Valley. A high surface O3 concentration is usually observed between January and April, while a low surface O3 concentration is found between June and August. Analysis of daily variations in surface O3 and the precursors - NO, NO2, CO, NMHC and UVb, indicate that the surface O3 photochemistry in this study area exhibits a positive response to the intensity and wavelength in UVb while being influenced by the concentration of NOx, particularly through tritration processes. Although results from our study suggested that NMHCs may influence the maximum O3 concentration, further investigation is required. Wind direction during different monsoons was found to influence the concentration of O3 around the Klang Valley. HYSPLIT back trajectories (-72 h) were used to indicate the air-mass transport patterns on days with high concentrations of surface O3 in the study area. Results show that 47% of the high O3 days was associated with the localized circulation. The remaining 32% and 22% were associated with mid-range and long-range transport across the South China Sea from the northeast.

Ion and laser microprobes applied to the measurement of corrosion produced hydrogen on a microscopic scale.

NASA Technical Reports Server (NTRS)

Gray, H. R.

1972-01-01

Use of an ion microprobe and a laser microprobe to measure concentrations of corrosion-produced hydrogen on a microscopic scale. Hydrogen concentrations of several thousand ppm were measured by both analytical techniques below corroded and fracture surfaces of hot salt stress corroded titanium alloy specimens. This extremely high concentration compares with only about 100 ppm hydrogen determined by standard vacuum fusion chemical analyses of bulk samples. Both the ion and laser microprobes were used to measure hydrogen concentration profiles in stepped intervals to substantial depths below the original corroded and fracture surfaces. For the ion microprobe, the area of local analysis was 22 microns in diameter and for the laser microprobe, the area of local analysis was about 300 microns in diameter. The segregation of hydrogen below fracture surfaces supports a previously proposed theory that corrosion-produced hydrogen is responsible for hot salt stress corrosion embrittlement and cracking of titanium alloys. These advanced analytical techniques suggest great potential for many areas of stress corrosion and hydrogen embrittlement research, quality control, and field inspection of corrosion problems. For example, it appears possible that a contour map of hydrogen distribution at notch roots and crack tips could be quantitatively determined. Such information would be useful in substantiating current theories of stress corrosion and hydrogen embrittlement.

Mapping cortical brain asymmetry in 17,141 healthy individuals worldwide via the ENIGMA Consortium.

PubMed

Kong, Xiang-Zhen; Mathias, Samuel R; Guadalupe, Tulio; Glahn, David C; Franke, Barbara; Crivello, Fabrice; Tzourio-Mazoyer, Nathalie; Fisher, Simon E; Thompson, Paul M; Francks, Clyde

2018-05-29

Hemispheric asymmetry is a cardinal feature of human brain organization. Altered brain asymmetry has also been linked to some cognitive and neuropsychiatric disorders. Here, the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Consortium presents the largest-ever analysis of cerebral cortical asymmetry and its variability across individuals. Cortical thickness and surface area were assessed in MRI scans of 17,141 healthy individuals from 99 datasets worldwide. Results revealed widespread asymmetries at both hemispheric and regional levels, with a generally thicker cortex but smaller surface area in the left hemisphere relative to the right. Regionally, asymmetries of cortical thickness and/or surface area were found in the inferior frontal gyrus, transverse temporal gyrus, parahippocampal gyrus, and entorhinal cortex. These regions are involved in lateralized functions, including language and visuospatial processing. In addition to population-level asymmetries, variability in brain asymmetry was related to sex, age, and intracranial volume. Interestingly, we did not find significant associations between asymmetries and handedness. Finally, with two independent pedigree datasets ( n = 1,443 and 1,113, respectively), we found several asymmetries showing significant, replicable heritability. The structural asymmetries identified and their variabilities and heritability provide a reference resource for future studies on the genetic basis of brain asymmetry and altered laterality in cognitive, neurological, and psychiatric disorders.

Clay mineralogy in different geomorphic surfaces in sugarcane areas

NASA Astrophysics Data System (ADS)

Camargo, L.; Marques, J., Jr.

2012-04-01

The crystallization of the oxides and hydroxides of iron and aluminum and kaolinite of clay fraction is the result of pedogenetic processes controlled by the relief. These minerals have influence on the physical and chemical attributes of soil and exhibit spatial dependence. The pattern of spatial distribution is influenced by forms of relief as the geomorphic surfaces. In this sense, the studies aimed at understanding the relationship between relief and the distribution pattern of the clay fraction attributes contribute to the delineation of specific areas of management in the field. The objective of this study was to evaluate the spatial distribution of oxides and hydroxides of iron and aluminum and kaolinite of clay fraction and its relationship with the physical and chemical attributes in different geomorphic surfaces. Soil samples were collected in a transect each 25 m (100 samples) and in the sides of the same (200 samples) as well as an area of 500 ha (1 sample each six hectare). Geomorphic surfaces (GS) in the transect were mapped in detail to support mapping the entire area. The soil samples were taken to the laboratory for chemical, physical, and mineralogical analysis, and the pattern of spatial distribution of soil attributes was obtained by statistics and geostatistics. The GS I is considered the oldest surface of the study area, with depositional character, and a slope ranging from 0 to 4%. GS II and III are considered to be eroded, and the surface II plan a gentle slope that extends from the edge of the surface until the beginning of I and III. The crystallographic characteristics of the oxides and hydroxides of iron and aluminum and kaolinite showed spatial dependence and the distribution pattern corresponding to the limits present of the GS in the field. Surfaces I and II showed the best environments to the degree of crystallinity of hematite and the surface III to the greatest degree of crystallinity of goethite agreeing to the pedoenvironment conditions of each surface. The rate goethite/(goethite+hematite) decreases the surface I to III this result is the variation of the source material that has an increase of clay which is characteristic of sandstone rock (Adamantine Formation) in the surface III. The rate kaolinite/(kaolinite+gibbsite) also shows a decrease of the surface I to the surface III. The spatial distribution pattern of mineralogy influenced the pattern of physical and chemical properties. On the surface III (with higher iron and gibbsite) had the best physical condition (lower density, higher porosity and aggregates) and greater phosphorus sorption. In this sense, the identification and mapping of the GSs, allowed a better understanding of cause and effect of the distribution of soils in the area, and the recognition of areas of controlled variability of soil attributes. These areas can be considered specific areas of management, useful for planning and management practices in the culture of sugarcane. Besides, suggesting criteria for the recognition of map units that would be equivalent to the future series of soils of the Brazilian System of Soil Classification.

Reduction of spatial distribution of risk factors for transportation of contaminants released by coal mining activities.

PubMed

Karan, Shivesh Kishore; Samadder, Sukha Ranjan

2016-09-15

It is reported that water-energy nexus composes two of the biggest development and human health challenges. In the present study we presented a Risk Potential Index (RPI) model which encapsulates Source, Vector (Transport), and Target risks for forecasting surface water contamination. The main aim of the model is to identify critical surface water risk zones for an open cast mining environment, taking Jharia Coalfield, India as the study area. The model also helps in feasible sampling design. Based on spatial analysis various risk zones were successfully delineated. Monthly RPI distribution revealed that the risk of surface water contamination was highest during the monsoon months. Surface water samples were analysed to validate the model. A GIS based alternative management option was proposed to reduce surface water contamination risk and observed 96% and 86% decrease in the spatial distribution of very high risk areas for the months June and July respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Framework for Analyzing the Whole Body Surface Area from a Single View

PubMed Central

Doretto, Gianfranco; Adjeroh, Donald

2017-01-01

We present a virtual reality (VR) framework for the analysis of whole human body surface area. Usual methods for determining the whole body surface area (WBSA) are based on well known formulae, characterized by large errors when the subject is obese, or belongs to certain subgroups. For these situations, we believe that a computer vision approach can overcome these problems and provide a better estimate of this important body indicator. Unfortunately, using machine learning techniques to design a computer vision system able to provide a new body indicator that goes beyond the use of only body weight and height, entails a long and expensive data acquisition process. A more viable solution is to use a dataset composed of virtual subjects. Generating a virtual dataset allowed us to build a population with different characteristics (obese, underweight, age, gender). However, synthetic data might differ from a real scenario, typical of the physician’s clinic. For this reason we develop a new virtual environment to facilitate the analysis of human subjects in 3D. This framework can simulate the acquisition process of a real camera, making it easy to analyze and to create training data for machine learning algorithms. With this virtual environment, we can easily simulate the real setup of a clinic, where a subject is standing in front of a camera, or may assume a different pose with respect to the camera. We use this newly designated environment to analyze the whole body surface area (WBSA). In particular, we show that we can obtain accurate WBSA estimations with just one view, virtually enabling the possibility to use inexpensive depth sensors (e.g., the Kinect) for large scale quantification of the WBSA from a single view 3D map. PMID:28045895

Rubber friction on road surfaces: Experiment and theory for low sliding speeds

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

Lorenz, B.; Persson, B. N. J.; Oh, Y. R.

We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, theremore » is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.« less

Concentration transient analysis of antimony surface segregation during Si(100) molecular beam epitaxy

NASA Technical Reports Server (NTRS)

Markert, L. C.; Greene, J. E.; Ni, W.-X.; Hansson, G. V.; Sundgren, J.-E.

1991-01-01

Antimony surface segregation during Si(100) molecular beam epitaxy (MBE) was investigated at temperatures T(sub s) = 515 - 800 C using concentration transient analysis (CTA). The dopant surface coverage Theta, bulk fraction gamma, and incorporation probability sigma during MBE were determined from secondary-ion mass spectrometry depth profiles of modulation-doped films. Programmed T(sub s) changes during growth were used to trap the surface-segregated dopant overlayer, producing concentration spikes whose integrated area corresponds to Theta. Thermal antimony doping by coevaporation was found to result in segregation strongly dependent on T(sub s) with Theta(sub Sb) values up to 0.9 monolayers (ML): in films doped with Sb(+) ions accelerated by 100 V, Theta(sub Sb) was less than or equal to 4 x 10(exp -3) ML. Surface segregation of coevaporated antimony was kinematically limited for the film growth conditions in these experiments.

Neural representation of form-contingent color filling-in in the early visual cortex.

PubMed

Hong, Sang Wook; Tong, Frank

2017-11-01

Perceptual filling-in exemplifies the constructive nature of visual processing. Color, a prominent surface property of visual objects, can appear to spread to neighboring areas that lack any color. We investigated cortical responses to a color filling-in illusion that effectively dissociates perceived color from the retinal input (van Lier, Vergeer, & Anstis, 2009). Observers adapted to a star-shaped stimulus with alternating red- and cyan-colored points to elicit a complementary afterimage. By presenting an achromatic outline that enclosed one of the two afterimage colors, perceptual filling-in of that color was induced in the unadapted central region. Visual cortical activity was monitored with fMRI, and analyzed using multivariate pattern analysis. Activity patterns in early visual areas (V1-V4) reliably distinguished between the two color-induced filled-in conditions, but only higher extrastriate visual areas showed the predicted correspondence with color perception. Activity patterns allowed for reliable generalization between filled-in colors and physical presentations of perceptually matched colors in areas V3 and V4, but not in earlier visual areas. These findings suggest that the perception of filled-in surface color likely requires more extensive processing by extrastriate visual areas, in order for the neural representation of surface color to become aligned with perceptually matched real colors.

Thematic mapper research in the earth sciences: Small scale patches of suspended matter and phytoplankton in the Elbe River Estuary, German Bight and Tidal Flats

NASA Technical Reports Server (NTRS)

Grassl, H.; Doerffer, R.; Fischer, J.; Brockmann, C.; Stoessel, M.

1987-01-01

A Thematic Mapper (TM) field experiment was followed by a data analysis to determine TM capabilities for analysis of suspended matter and phytoplankton. Factor analysis showed that suspended matter concentration, atmospheric scattering, and sea surface temperature can be retrieved as independent factors which determine the variation in the TM data over water areas. Spectral channels in the near infrared open the possibility of determining the Angstrom exponent better than for the coastal zone color scanner. The suspended matter distribution may then be calculated by the absolute radiance of channel 2 or 3 or the ratio of both. There is no indication of whether separation of chlorophyll is possible. The distribution of suspended matter and sea surface temperature can be observed with the expected fine structure. A good correlation between water depth and suspended matter distribution as found from ship data can now be analyzed for an entire area by the synoptic view of the TM scenes.

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.

Sterols as biomarkers in the surface microlayer of the estuarine areas.

PubMed

Alsalahi, Murad Ali; Latif, Mohd Talib; Ali, Masni Mohd; Dominick, Doreena; Khan, Md Firoz; Mustaffa, Nur Ili Hamizah; Nadzir, Mohd Shahrul Mohd; Nasher, Essam; Zakaria, Mohamad Pauzi

2015-04-15

This study aims to determine the concentration of sterols used as biomarkers in the surface microlayer (SML) in estuarine areas of the Selangor River, Malaysia. Samples were collected during different seasons through the use of a rotation drum. The analysis of sterols was performed using gas chromatography equipped with a flame ionisation detector (GC-FID). The results showed that the concentrations of total sterols in the SML ranged from 107.06 to 505.55 ng L(-1). The total sterol concentration was found to be higher in the wet season. Cholesterol was found to be the most abundant sterols component in the SML. The diagnostic ratios of sterols show the influence of natural sources and waste on the contribution of sterols in the SML. Further analysis, using principal component analysis (PCA), showed distinct inputs of sterols derived from human activity (40.58%), terrigenous and plant inputs (22.59%) as well as phytoplankton and marine inputs (17.35%). Copyright © 2015 Elsevier Ltd. All rights reserved.

Characteristics of rapeseed oil cake using nitrogen adsorption

NASA Astrophysics Data System (ADS)

Sokołowska, Z.; Bowanko, G.; Boguta, P.; Tys, J.; Skiba, K.

2013-09-01

Adsorption of nitrogen on the rapeseed oil cake and rapeseed oil cake with wheat meal extrudates was investigated. The results are presented as adsorption-desorption isotherms. The Brunauer-Emmet and Teller equation was used to analyse the experimental sorption data. To obtain estimates of the surface area and surface fractal dimension, the sorption isotherms were analyzed using the Brunauer-Emmet and Teller and Frenkel-Halsey-Hill equations. Mesopore analysis was carried out using the Dollimore and Heal method. The properties and surface characteristic of rapeseed oil cake extrudates are related to different basic properties of particular samples and duration of the extrusion process. Extrusion conditions lead to essential differences in particular products. For all kinds of rapeseed oil cakes the amount of adsorbed nitrogen was different, but for the rapeseed oil cake extrudates a large amount of adsorbed nitrogenwas observed. The average surface area of the rapeseed oil cake extrudates was about 6.5-7.0 m2 g-1, whereas it was equal to about 4.0-6.0 m2 g-1 for rapeseed oil cake with the wheat meal extrudates. In the case of non-extruded rapeseed oil cake and wheat meal, the dominant group included ca. 2 and 5 nmpores. The values of surface fractal dimension suggested that the surface of the extrudates was more homogenous than that of the raw material. Duration of the extrusion process to 80 s resulted in a decrease in the specific surface area, surface fractal dimension, and porosity of the extrudates.

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.

Trend analysis of time-series phenology of North America derived from satellite data

USGS Publications Warehouse

Reed, B.C.

2006-01-01

Remote sensing information has been used in studies of the seasonal dynamics (phenology) of the land surface since the 1980s. While our understanding of remote sensing phenology is still in development, it is regarded as a key to understanding land-surface processes over large areas. Phenologic metrics, including start of season, end of season, duration of season, and seasonally integrated greenness, were derived from 8 km advanced very high resolution radiometer (AVHRR) data over North America spanning the years 1982-2003. Trend analysis was performed on annual summaries of the metrics to determine areas with increasing or decreasing growing season trends for the time period under study. Results show a trend toward earlier starts of season in limited areas of the mixed boreal forest, and a trend toward later end of season in well-defined areas of New England and southeastern Canada. Results in Saskatchewan, Canada, include a trend toward longer duration of season over a well-defined area, principally as a result of regional changes in land use practices. Changing seasonality appears to be an integrated response to a complex of factors, including climate change, but also, in many places, changes in land use practices. Copyright ?? 2006 by V. H. Winston & Son, Inc. All rights reserved.

Improving the corrosion resistance of proton exchange membrane fuel cell carbon supports by pentafluorophenyl surface functionalization

NASA Astrophysics Data System (ADS)

Forouzandeh, Farisa; Li, Xiaoan; Banham, Dustin W.; Feng, Fangxia; Joseph Kakanat, Abraham; Ye, Siyu; Birss, Viola

2018-02-01

In this study, the effect of surface functionalization on the electrochemical corrosion resistance of a high surface area, mesoporous colloid imprinted carbon powder (CIC), as well as microporous Vulcan carbon (VC, serving as the benchmark), was demonstrated, primarily for PEM fuel cell applications. CIC-22, which is highly hydrophilic and was synthesized with 22 nm silica colloid templates, and as-received, mildly hydrophobic, VC powders, were functionalized with 2,3,4,5,6-pentafluorophenyl (-PhF5) surface groups using a straightforward diazonium reduction reaction. These carbons were then subjected to corrosion testing, involving a potential cycling-step sequence in room temperature 0.5 M H2SO4. Using cyclic voltammetry and charge/time analysis, the double layer and pseudo-capacitive gravimetric charges of the carbons, prior to and after the application of these potential steps, were tracked in order to obtain information about surface area changes and the extent of carbon oxidation, respectively. It is shown that the corrosion resistance was improved by ca. 50-80% by surface functionalization, likely due to a combination of surface passivation (loss of carbon active sites) and increased surface hydrophobicity.

Method and system for near-field spectroscopy using targeted deposition of nanoparticles

NASA Technical Reports Server (NTRS)

Anderson, Mark S. (Inventor)

2012-01-01

There is provided in one embodiment of the invention a method for analyzing a sample material using surface enhanced spectroscopy. The method comprises the steps of imaging the sample material with an atomic force microscope (AFM) to select an area of interest for analysis, depositing nanoparticles onto the area of interest with an AFM tip, illuminating the deposited nanoparticles with a spectrometer excitation beam, and disengaging the AFM tip and acquiring a localized surface enhanced spectrum. The method may further comprise the step of using the AFM tip to modulate the spectrometer excitation beam above the deposited nanoparticles to obtain improved sensitivity data and higher spatial resolution data from the sample material. The invention further comprises in one embodiment a system for analyzing a sample material using surface enhanced spectroscopy.

Correlation of lung surface area to apoptosis and proliferation in human emphysema.

PubMed

Imai, K; Mercer, B A; Schulman, L L; Sonett, J R; D'Armiento, J M

2005-02-01

Pulmonary emphysema is associated with alterations in matrix proteins and protease activity. These alterations may be linked to programmed cell death by apoptosis, potentially influencing lung architecture and lung function. To evaluate apoptosis in emphysema, lung tissue was analysed from 10 emphysema patients and six individuals without emphysema (normal). Morphological analysis revealed alveolar cells in emphysematous lungs with convoluted nuclei characteristic of apoptosis. DNA fragmentation was detected using terminal deoxynucleotide transferase-mediated dUTP nick-end labelling (TUNEL) and gel electrophoresis. TUNEL revealed higher apoptosis in emphysematous than normal lungs. Markers of apoptosis, including active caspase-3, proteolytic fragment of poly (ADP-ribose) polymerase, Bax and Bad, were detected in emphysematous lungs. Linear regression showed that apoptosis was inversely correlated with surface area. Emphysematous lungs demonstrated lower surface areas and increased cell proliferation. There was no correlation between apoptosis and proliferation, suggesting that, although both events increase during emphysema, they are not in equilibrium, potentially contributing to reduced lung surface area. In summary, cell-based mechanisms associated with emphysematous parenchymal damage include increased apoptosis and cell proliferation. Apoptosis correlated with airspace enlargement, supporting epidemiological evidence of the progressive nature of emphysema. These data extend the understanding of cell dynamics and structural changes within the lung during emphysema pathogenesis.

The application of LANDSAT-1 imagery for monitoring strip mines in the new river watershed in northeast Tennessee, part 2

NASA Technical Reports Server (NTRS)

Shahrokhi, F. (Principal Investigator); Sharber, L. A.

1977-01-01

The author has identified the following significant results. LANDSAT imagery and supplementary aircraft photography of the New River drainage basin were subjected to a multilevel analysis using conventional photointerpretation methods, densitometric techniques, multispectral analysis, and statistical tests to determine the accuracy of LANDSAT-1 imagery for measuring strip mines of common size. The LANDSAT areas were compared with low altitude measurements. The average accuracy over all the mined land sample areas mapped from LANDSAT-1 was 90%. The discrimination of strip mine subcategories is somewhat limited on LANDSAT imagery. A mine site, whether active or inactive, can be inferred by lack of vegetation, by shape, or image texture. Mine ponds are difficult or impossible to detect because of their small size and turbidity. Unless bordered and contrasted with vegetation, haulage roads are impossible to delineate. Preparation plants and refuge areas are not detectable. Density slicing of LANDSAT band 7 proved most useful in the detection of reclamation progress within the mined areas. For most state requirements for year-round monitoring of surface mined land, LANDSAT is of limited value. However, for periodic updating of regional surface maps, LANDSAT may provide sufficient accuracies for some users.

A diffusive ink transport model for lipid dip-pen nanolithography

NASA Astrophysics Data System (ADS)

Urtizberea, A.; Hirtz, M.

2015-09-01

Despite diverse applications, phospholipid membrane stacks generated by dip-pen nanolithography (DPN) still lack a thorough and systematic characterization that elucidates the whole ink transport process from writing to surface spreading, with the aim of better controlling the resulting feature size and resolution. We report a quantitative analysis and modeling of the dependence of lipid DPN features (area, height and volume) on dwell time and relative humidity. The ink flow rate increases with humidity in agreement with meniscus size growth, determining the overall feature size. The observed time dependence indicates the existence of a balance between surface spreading and the ink flow rate that promotes differences in concentration at the meniscus/substrate interface. Feature shape is controlled by the substrate surface energy. The results are analyzed within a modified model for the ink transport of diffusive inks. At any humidity the dependence of the area spread on the dwell time shows two diffusion regimes: at short dwell times growth is controlled by meniscus diffusion while at long dwell times surface diffusion governs the process. The critical point for the switch of regime depends on the humidity.Despite diverse applications, phospholipid membrane stacks generated by dip-pen nanolithography (DPN) still lack a thorough and systematic characterization that elucidates the whole ink transport process from writing to surface spreading, with the aim of better controlling the resulting feature size and resolution. We report a quantitative analysis and modeling of the dependence of lipid DPN features (area, height and volume) on dwell time and relative humidity. The ink flow rate increases with humidity in agreement with meniscus size growth, determining the overall feature size. The observed time dependence indicates the existence of a balance between surface spreading and the ink flow rate that promotes differences in concentration at the meniscus/substrate interface. Feature shape is controlled by the substrate surface energy. The results are analyzed within a modified model for the ink transport of diffusive inks. At any humidity the dependence of the area spread on the dwell time shows two diffusion regimes: at short dwell times growth is controlled by meniscus diffusion while at long dwell times surface diffusion governs the process. The critical point for the switch of regime depends on the humidity. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04352b

[Spatial variability of surface soil nutrients in the landslide area of Beichuan County, South- west China, after 5 · 12 Wenchuan Earthquake].

PubMed

Mai, Ji-shan; Zhao, Ting-ning; Zheng, Jiang-kun; Shi, Chang-qing

2015-12-01

Based on grid sampling and laboratory analysis, spatial variability of surface soil nutrients was analyzed with GS⁺ and other statistics methods on the landslide area of Fenghuang Mountain, Leigu Town, Beichuan County. The results showed that except for high variability of available phosphorus, other soil nutrients exhibited moderate variability. The ratios of nugget to sill of the soil available phosphorus and soil organic carbon were 27.9% and 28.8%, respectively, showing moderate spatial correlation, while the ratios of nugget to sill of the total nitrogen (20.0%), total phosphorus (24.3%), total potassium (11.1%), available nitrogen (11.2%), and available potassium (22.7%) suggested strong spatial correlation. The total phosphorus had the maximum range (1232.7 m), followed by available nitrogen (541.27 m), total nitrogen (468.35 m), total potassium (136.0 m), available potassium (128.7 m), available phosphorus (116.6 m), and soil organic carbon (93.5 m). Soil nutrients had no significant variation with the increase of altitude, but gradually increased from the landslide area, the transition area, to the little-impacted area. The total and available phosphorus contents of the landslide area decreased by 10.3% and 79.7% compared to that of the little-impacted area, respectively. The soil nutrient contents in the transition area accounted for 31.1%-87.2% of that of the little-impacted area, with the nant reason for the spatial variability of surface soil nutrients.

Acute and subchronic toxicity analysis of surface modified paclitaxel attached hydroxyapatite and titanium dioxide nanoparticles

PubMed Central

Venkatasubbu, Gopinath Devanand; Ramasamy, S; Gaddam, Pramod Reddy; Kumar, J

2015-01-01

Nanoparticles are widely used for targeted drug delivery applications. Surface modification with appropriate polymer and ligands is carried out to target the drug to the affected area. Toxicity analysis is carried out to evaluate the safety of the surface modified nanoparticles. In this study, paclitaxel attached, folic acid functionalized, polyethylene glycol modified hydroxyapatite and titanium dioxide nanoparticles were used for targeted drug delivery system. The toxicological behavior of the system was studied in vivo in rats and mice. Acute and subchronic studies were carried out. Biochemical, hematological, and histopathological analysis was also done. There were no significant alterations in the biochemical parameters at a low dosage. There was a small change in alkaline phosphatase (ALP) level at a high dosage. The results indicate a safe toxicological profile. PMID:26491315

Three-dimensional analysis of elbow soft tissue footprints and anatomy.

PubMed

Capo, John T; Collins, Christopher; Beutel, Bryan G; Danna, Natalie R; Manigrasso, Michaele; Uko, Linda A; Chen, Linda Y

2014-11-01

Tendinous and ligamentous injuries commonly occur in the elbow. This study characterized the location, surface areas, and origin and insertional footprints of major elbow capsuloligamentous and tendinous structures in relation to bony landmarks with the use of a precision 3-dimensional modeling system. Nine unpaired cadaveric elbow specimens were dissected and mounted on a custom jig. Mapping of the medial collateral ligament (MCL), lateral ulnar collateral ligament (LUCL), triceps, biceps, brachialis, and capsular reflections was then performed with 3-dimensional digitizing technology. The location, surface areas, and footprints of the soft tissues were calculated. The MCL had a mean origin (humeral) footprint of 216 mm(2), insertional footprint of 154 mm(2), and surface area of 421 mm(2). The LUCL had a mean origin footprint of 136 mm(2), an insertional footprint of 142 mm(2), and a surface area of 532 mm(2). Of the tendons, the triceps maintained the largest insertional footprint, followed by the brachialis and the biceps (P < .001-.03). The MCL, LUCL, and biceps footprint locations were consistent, with little variability. The surface areas of the anterior (1251 mm(2)) and posterior (1147 mm(2)) capsular reflections were similar (P = .82), and the anterior capsule extended farther proximally. Restoring the normal anatomy of key elbow capsuloligamentous and tendinous structures is crucial for effective reconstruction after bony or soft tissue trauma. This study provides the upper extremity surgeon with information that may aid in restoring elbow biomechanics and preserving range of motion in these patients. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

High surface area neodymium phosphate nano particles by modified aqueous sol-gel method

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

Sankar, Sasidharan; Warrier, Krishna Gopakumar, E-mail: wwarrierkgk@yahoo.co.in; Komban, Rajesh

2011-12-15

Graphical abstract: Synthesis of nano rod shaped neodymium phosphate particles with specific surface area as high as 107 m{sup 2} g{sup -1} and particles could be compacted and sintered at as low as 1300 Degree-Sign C to a density of 98.5% (theoretical) with an average grain size of {approx}1 {mu}m. Highlights: Black-Right-Pointing-Pointer Nano size neodymium phosphate is synthesized and characterized using a novel modified aqueous sol gel process. Black-Right-Pointing-Pointer Specific surface area above 100 m{sup 2} g{sup -1} achieved without the addition of any complexing agents. Black-Right-Pointing-Pointer High sintered density reported than the density obtained for powder synthesized through conventionalmore » solid state reaction. Black-Right-Pointing-Pointer The particles are nano sized and have rod shape morphology and are retained at higher temperatures. Black-Right-Pointing-Pointer An average grain size of {approx}1 {mu}m obtained for sintered NdPO{sub 4} after thermal etching at 1400 Degree-Sign C. -- Abstract: Synthesis of nano rod shaped neodymium phosphate (NdPO{sub 4}) particles with specific surface area as high as 107 m{sup 2}g{sup -1} and an average length of 50 nm with aspect ratio 5 was achieved using modified sol gel method. Crystallite size calculated from the X-ray diffraction data by applying Scherer equation was 5 nm for the precursor gel after calcination at 400 Degree-Sign C. NdPO{sub 4} was first precipitated from neodymium nitrate solution using phosphoric acid followed by peptization using dilute nitric acid and further gelation in ammonia atmosphere. The calcined gel powders were further characterized by surface area (Brunauer-Emmet-Teller nitrogen adsorption analysis), Transmission electron microscopy, scanning electron microscopy, UV-vis and FT-IR analysis. Transmission electron microscopy confirms the formation of rod like morphology from the sol, gel and the calcined particles in nano size range. These particles could be compacted and sintered at as low as 1300 Degree-Sign C to a density of 98.5% (theoretical) with an average grain size of {approx}1 {mu}m.« less

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.

Landslide prediction using combined deterministic and probabilistic methods in hilly area of Mt. Medvednica in Zagreb City, Croatia

NASA Astrophysics Data System (ADS)

Wang, Chunxiang; Watanabe, Naoki; Marui, Hideaki

2013-04-01

The hilly slopes of Mt. Medvednica are stretched in the northwestern part of Zagreb City, Croatia, and extend to approximately 180km2. In this area, landslides, e.g. Kostanjek landslide and Črešnjevec landslide, have brought damage to many houses, roads, farmlands, grassland and etc. Therefore, it is necessary to predict the potential landslides and to enhance landslide inventory for hazard mitigation and security management of local society in this area. We combined deterministic method and probabilistic method to assess potential landslides including their locations, size and sliding surfaces. Firstly, this study area is divided into several slope units that have similar topographic and geological characteristics using the hydrology analysis tool in ArcGIS. Then, a GIS-based modified three-dimensional Hovland's method for slope stability analysis system is developed to identify the sliding surface and corresponding three-dimensional safety factor for each slope unit. Each sliding surface is assumed to be the lower part of each ellipsoid. The direction of inclination of the ellipsoid is considered to be the same as the main dip direction of the slope unit. The center point of the ellipsoid is randomly set to the center point of a grid cell in the slope unit. The minimum three-dimensional safety factor and corresponding critical sliding surface are also obtained for each slope unit. Thirdly, since a single value of safety factor is insufficient to evaluate the slope stability of a slope unit, the ratio of the number of calculation cases in which the three-dimensional safety factor values less than 1.0 to the total number of trial calculation is defined as the failure probability of the slope unit. If the failure probability is more than 80%, the slope unit is distinguished as 'unstable' from other slope units and the landslide hazard can be mapped for the whole study area.

The influence of muscle pennation angle and cross-sectional area on contact forces in the ankle joint.

PubMed

Sopher, Ran S; Amis, Andrew A; Davies, D Ceri; Jeffers, Jonathan Rt

2017-01-01

Data about a muscle's fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep pennation angles. Inter-subject variability in muscle architecture affected ankle muscle and contact loads only slightly. The link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.

Tungsten Disulfide Nanotubes Reinforced Biodegradable Polymers for Bone Tissue Engineering

PubMed Central

Lalwani, Gaurav; Henslee, Allan M.; Farshid, Behzad; Parmar, Priyanka; Lin, Liangjun; Qin, Yi-Xian; Kasper, F. Kurtis; Mikos, Antonios G.; Sitharaman, Balaji

2013-01-01

In this study, we have investigated the efficacy of inorganic nanotubes as reinforcing agents to improve the mechanical properties of poly(propylene fumarate) (PPF) composites as a function of nanomaterial loading concentration (0.01-0.2 wt%). Tungsten disulfide nanotubes (WSNTs) were used as reinforcing agents in the experimental groups. Single- and multi- walled carbon nanotubes (SWCNTs and MWCNTs) were used as positive controls, and crosslinked PPF composites were used as baseline control. Mechanical testing (compression and three-point bending) shows a significant enhancement (up to 28-190%) in the mechanical properties (compressive modulus, compressive yield strength, flexural modulus, and flexural yield strength) of WSNT reinforced PPF nanocomposites compared to the baseline control. In comparison to positive controls, at various concentrations, significant improvements in the mechanical properties of WSNT nanocomposites were also observed. In general, the inorganic nanotubes (WSNTs) showed a better (up to 127%) or equivalent mechanical reinforcement compared to carbon nanotubes (SWCNTs and MWCNTs). Sol fraction analysis showed significant increases in the crosslinking density of PPF in the presence of WSNTs (0.01-0.2 wt%). Transmission electron microscopy (TEM) analysis on thin sections of crosslinked nanocomposites showed the presence of WSNTs as individual nanotubes in the PPF matrix, whereas SWCNTs and MWCNTs existed as micron sized aggregates. The trend in the surface area of nanostructures obtained by BET surface area analysis was SWCNTs > MWCNTs > WSNTs. The BET surface area analysis, TEM analysis, and sol fraction analysis results taken together suggest that chemical composition (inorganic vs. carbon nanomaterials), presence of functional groups (such as sulfide and oxysulfide), and individual dispersion of the nanomaterials in the polymer matrix (absence of aggregation of the reinforcing agent) are the key parameters affecting the mechanical properties of nanostructure-reinforced PPF composites, and the reason for the observed increases in the mechanical properties compared to the baseline and positive controls. PMID:23727293

Human hair-derived high surface area porous carbon material for the adsorption isotherm and kinetics of tetracycline antibiotics.

PubMed

Ahmed, M J; Islam, Md Azharul; Asif, M; Hameed, B H

2017-11-01

In this work, a human hair-derived high surface area porous carbon material (HHC) was prepared using potassium hydroxide activation. The morphology and textural properties of the HHC structure, along with its adsorption performance for tetracycline (TC) antibiotics, were evaluated. HHC showed a high surface area of 1505.11m 2 /g and 68.34% microporosity. The effects of most important variables, such as initial concentration (25-355mg/L), solution pH (3-13), and temperatures (30-50°C), on the HHC adsorption performance were investigated. Isotherm data analysis revealed the favorable application of the Langmuir model, with maximum TC uptakes of 128.52, 162.62, and 210.18mg/g at 30, 40, and 50°C, respectively. The experimental data of TC uptakes versus time were analyzed efficiently using a pseudo-first order model. Porous HHC could be an efficient adsorbent for eliminating antibiotic pollutants in wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Surface Roughness Relief

NASA Astrophysics Data System (ADS)

Marras, L.; Fontana, R.; Gambino, M. C.; Greco, M.; Materazzi, M.; Pampaloni, E.; Pezzati, L.; Poggi, P.

The knowledge of the shape of an artwork is an important element for its study and conservation. When dealing with a stone statue, roughness measurement is a very useful contribution to document its surface conditions, to assess either changes due to restoration intervention or surface decays due to weathering agents, and to monitor its time-evolution in terms of shape variations. In this work we present the preliminary results of the statistical analysis carried out on acquired data relative to six areas of the Michelangelo's David marble statue, representative of differently degraded surfaces. Determination of the roughness and its relative characteristic wavelength is shown.

Finding glenoid surface on scapula in 3D medical images for shoulder joint implant operation planning: 3D OCR

NASA Astrophysics Data System (ADS)

Mohammad Sadeghi, Majid; Kececi, Emin Faruk; Bilsel, Kerem; Aralasmak, Ayse

2017-03-01

Medical imaging has great importance in earlier detection, better treatment and follow-up of diseases. 3D Medical image analysis with CT Scan and MRI images has also been used to aid surgeries by enabling patient specific implant fabrication, where having a precise three dimensional model of associated body parts is essential. In this paper, a 3D image processing methodology for finding the plane on which the glenoid surface has a maximum surface area is proposed. Finding this surface is the first step in designing patient specific shoulder joint implant.

Statistical analysis of $sup 239-240$Pu and $sup 241$Am contamination of soil and vegetation on NAEG study sites

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

Gilbert, R.O.; Eberhardt, L.L.; Fowler, E.B.

Reported here are results of the statistical design and analysis work conducted during Calendar Year 1974 for the Nevada Applied Ecology Group (NAEG) at plutonium study sites on the Nevada Test Site (NTS) and the Tonopah Test Range (TTR). Estimates of $sup 239-240$Pu inventory in surface soil (0 to 5-cm depth) are given for each of the NAEG intensive study sites, together with activity maps based on FIDLER surveys showing the field areas to which these estimates apply. There is evidence of a preliminary nature to suggest that the plutonium present in surface soil may be covered by a thinmore » (less than 2.5 cm) layer of soil whose alpha activity is considerably less than that directly below. Computer-drawn $sup 239-240$Pu concentration contours and three-dimensional surfaces in soil and vegetation are given for Area 13 and GMX as a first attempt at estimating the geographical distribution of $sup 239-240$Pu at these sites. (CH)« less

X-Band wave radar system for monitoring and risk management of the coastal infrastructures

NASA Astrophysics Data System (ADS)

Ludeno, Giovanni; Soldovieri, Francesco; Serafino, Francesco

2017-04-01

The presence of the infrastructures in coastal region entails an increase of the sea level and the shift of the sediment on the bottom with a continuous change of the coastline. In order to preserve the coastline, it has been necessary to resort the use of applications coastal engineering, as the construction of the breakwaters for preventing the coastal erosion. In this frame, the knowledge of the sea state parameters, as wavelength, period and significant wave height and of surface current and bathymetry can be used for the harbor operations and to prevent environmental disasters. In the last years, the study of the coastal phenomena and monitoring of the sea waves impact on the coastal infrastructures through the analysis of images acquired by marine X-band radars is of great interest [1-3]. The possibility to observe the sea surface from radar images is due to the fact that the X-band electromagnetic waves interact with the sea capillary waves (Bragg resonance), which ride on the gravity waves. However, the image acquired by a X-band radar is not the direct representation of the sea state, but it represents the sea surface as seen by the radar. Accordingly, to estimate the sea state parameters as, direction, wavelength, period of dominant waves, the significant wave height as well as the bathymetry and surface current, through a time stack of radar data are required advanced data processing procedures. In particular, in the coastal areas due to the non-uniformity of sea surface current and bathymetry fields is necessary a local analysis of the sea state parameters. In order to analyze the data acquired in coastal area an inversion procedure defined "Local Method" is adopted, which is based on the spatial partitioning of the investigated area in partially overlapping sub-areas. In addition, the analysis of the sea spectrum of each sub-area allows us to retrieve the local sea state parameters. In particular, this local analysis allows us to detect the reflected waves from the coastal infrastructures, e.g. from the harbor jetties. In fact, the reflected waves may significantly complicate the harbour activities (e.g., berthing operations), as they interfere with the oncoming waves thus creating a confused sea [2]. References [1] G. Ludeno, C. Brandini, C. Lugni, D. Arturi, A. Natale, F. Soldovieri, B. Gozzini, F. Serafino, "Remocean System for the Detection of the Reflected Waves from the Costa Concordia Ship Wreck", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, Vol.7, no.3, pp.3011-3018, July 2014. [2] G. Ludeno, F. Reale, F. Dentale, E. Pugliese Carratelli, A. Natale, F. Soldovieri, F. Serafino "An X-Band Radar System for Bathymetry and Wave Field Analysis in Harbor Area", Sensors, Vol.15, no.1, pp. 1691-1707, January 2015. [3] F. Raffa, G. Ludeno, B. Patti, F. Soldovieri, S. Mazzola, and F. Serafino, "X-band wave radar for coastal upwelling detection off the southern coast of Sicily.", Journal of Atmospheric and Oceanic Technology, January 2017, Vol. 34, No. 1, Published online on 22 Dec 2016.

Error reduction in three-dimensional metrology combining optical and touch probe data

NASA Astrophysics Data System (ADS)

Gerde, Janice R.; Christens-Barry, William A.

2010-08-01

Analysis of footwear under the Harmonized Tariff Schedule of the United States (HTSUS) is partly based on identifying the boundary ("parting line") between the "external surface area upper" (ESAU) and the sample's sole. Often, that boundary is obscured. We establish the parting line as the curved intersection between the sample outer surface and its insole surface. The outer surface is determined by discrete point cloud coordinates obtained using a laser scanner. The insole surface is defined by point cloud data, obtained using a touch probe device-a coordinate measuring machine (CMM). Because these point cloud data sets do not overlap spatially, a polynomial surface is fitted to the insole data and extended to intersect a mesh fitted to the outer surface point cloud. This line of intersection defines the ESAU boundary, permitting further fractional area calculations to proceed. The defined parting line location is sensitive to the polynomial used to fit experimental data. Extrapolation to the intersection with the ESAU can heighten this sensitivity. We discuss a methodology for transforming these data into a common reference frame. Three scenarios are considered: measurement error in point cloud coordinates, from fitting a polynomial surface to a point cloud then extrapolating beyond the data set, and error from reference frame transformation. These error sources can influence calculated surface areas. We describe experiments to assess error magnitude, the sensitivity of calculated results on these errors, and minimizing error impact on calculated quantities. Ultimately, we must ensure that statistical error from these procedures is minimized and within acceptance criteria.

A Mathematical Model for Pathogen Cross-Contamination Dynamics during the Postharvest Processing of Leafy Greens.

PubMed

Mokhtari, Amir; Oryang, David; Chen, Yuhuan; Pouillot, Regis; Van Doren, Jane

2018-01-08

We developed a probabilistic mathematical model for the postharvest processing of leafy greens focusing on Escherichia coli O157:H7 contamination of fresh-cut romaine lettuce as the case study. Our model can (i) support the investigation of cross-contamination scenarios, and (ii) evaluate and compare different risk mitigation options. We used an agent-based modeling framework to predict the pathogen prevalence and levels in bags of fresh-cut lettuce and quantify spread of E. coli O157:H7 from contaminated lettuce to surface areas of processing equipment. Using an unbalanced factorial design, we were able to propagate combinations of random values assigned to model inputs through different processing steps and ranked statistically significant inputs with respect to their impacts on selected model outputs. Results indicated that whether contamination originated on incoming lettuce heads or on the surface areas of processing equipment, pathogen prevalence among bags of fresh-cut lettuce and batches was most significantly impacted by the level of free chlorine in the flume tank and frequency of replacing the wash water inside the tank. Pathogen levels in bags of fresh-cut lettuce were most significantly influenced by the initial levels of contamination on incoming lettuce heads or surface areas of processing equipment. The influence of surface contamination on pathogen prevalence or levels in fresh-cut bags depended on the location of that surface relative to the flume tank. This study demonstrates that developing a flexible yet mathematically rigorous modeling tool, a "virtual laboratory," can provide valuable insights into the effectiveness of individual and combined risk mitigation options. © 2018 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

Implementation of whole body scanner for determining somatotype index at Chang Gung Memorial Hospital.

PubMed

Liu, T H; Chiou, W K; Lin, J D; Yu, C Y

2001-11-01

Body mass index (BMI) and waist-hip ratio (WHR) using 1-dimensional circumference data have been proven to be highly related to blood pressure and total cholesterol; these 2 indices have been widely used as health indicators in preventive diagnosis and health examination. Sophisticated software, which allows calculation of the triangular mesh related to the body surface in 3D space, is capable of computing the circumference, width, sectional surface, volume, and surface area of the body. Chang Gung Whole Body Scanner (CGWBS) was used to capture 3D whole body surface images. In this study, the human body was divided into 10 segments consisting of the head, breast, wrist, hip, upper arm, forearm, hand, thigh, calf, and foot. Five independent assessments were made on a total of 32 anthropometric sites, including 12 circumferences, 3 widths, 3 profile areas, 7 surface areas, and 7 volumes. In this study, the somatotype index (SI) was computed through anthropometric data after 1,323 subjects were investigated. Correlation analysis was used to describe the relationship between BMI, WHR, SI, and anthropometric data. One-way analysis of variance (ANOVA) and Duncan's multiple range tests were used to examine differences between examination variables across sex and SI groups. This study found 4 somatotypes from anthropometric data. SI determined by CGWBS has better correlation with anthropometry than WHR or BMI. Of the 644 male subjects, 155 were in the ectomorph group, 232 in the semi-mesomorph group, 136 in the full-mesomorph group, and 121 in the endomorph group. Of the 679 female subjects, 160 were in the ectomorph group, 235 in the semi-mesomorph group, 168 in the full-mesomorph group, and 116 in the endomorph group. The results show that SI has great potential to perform precise somatotype classification.

Optimal Mass Transport for Shape Matching and Comparison

PubMed Central

Su, Zhengyu; Wang, Yalin; Shi, Rui; Zeng, Wei; Sun, Jian; Luo, Feng; Gu, Xianfeng

2015-01-01

Surface based 3D shape analysis plays a fundamental role in computer vision and medical imaging. This work proposes to use optimal mass transport map for shape matching and comparison, focusing on two important applications including surface registration and shape space. The computation of the optimal mass transport map is based on Monge-Brenier theory, in comparison to the conventional method based on Monge-Kantorovich theory, this method significantly improves the efficiency by reducing computational complexity from O(n2) to O(n). For surface registration problem, one commonly used approach is to use conformal map to convert the shapes into some canonical space. Although conformal mappings have small angle distortions, they may introduce large area distortions which are likely to cause numerical instability thus resulting failures of shape analysis. This work proposes to compose the conformal map with the optimal mass transport map to get the unique area-preserving map, which is intrinsic to the Riemannian metric, unique, and diffeomorphic. For shape space study, this work introduces a novel Riemannian framework, Conformal Wasserstein Shape Space, by combing conformal geometry and optimal mass transport theory. In our work, all metric surfaces with the disk topology are mapped to the unit planar disk by a conformal mapping, which pushes the area element on the surface to a probability measure on the disk. The optimal mass transport provides a map from the shape space of all topological disks with metrics to the Wasserstein space of the disk and the pullback Wasserstein metric equips the shape space with a Riemannian metric. We validate our work by numerous experiments and comparisons with prior approaches and the experimental results demonstrate the efficiency and efficacy of our proposed approach. PMID:26440265

[The use of nucleolar morphological characteristics of birch seedlings for the assessment of environmental pollution].

PubMed

Karpova, S S; Kalaev, V N; Artiukov, V G; Trofimova, V A; OstashkovaL G, A D; Savko

2006-01-01

Micronucleus frequency in buccal mucosa from the oral cavity of children as well as nucleolar structural characteristics (surface area of single nucleoli as well as their number and type) in the root meristem of seed progeny of birch (Betula pendula Roth) were studied in some districts of Voronezh City and Voronezh Region (Novovoronezh Town, Zemlyansk Village). Similar trends of changes in cytogenetic parameters have been revealed for both subjects. Regression analysis allowed us to generate an equation relating the cytogenetic parameters of birch seed progeny (surface area of single nucleoli) and humans (frequency of micronuclei in buccal mucosa of children). This study can be considered as a result of cytogenetic monitoring of environmental pollution in some areas of Voronezh City and Voronezh Region.

Near surface geophysics techniques and geomorphological approach to reconstruct the hazard cave map in historical and urban areas

NASA Astrophysics Data System (ADS)

Lazzari, M.; Loperte, A.; Perrone, A.

2010-03-01

This work, carried out with an integrated methodological approach, focuses on the use of near surface geophysics techniques, such as ground penetrating radar and electrical resistivity tomography (ERT), and geomorphological analysis, in order to reconstruct the cave distribution and geometry in a urban context and, in particular, in historical centres. The interaction during recent centuries between human activity (caves excavation, birth and growth of an urban area) and the characters of the natural environment were the reasons of a progressive increase in hazard and vulnerability levels of several sites. The reconstruction of a detailed cave map distribution is the first step to define the anthropic and geomorphological hazard in urban areas, fundamental basis for planning and assessing the risk.

Surficial geology of Mars: A study in support of a penetrator mission to Mars

NASA Technical Reports Server (NTRS)

Spudis, P.; Greeley, R.

1976-01-01

Physiographic and surficial cover information were combined into unified surficial geology maps (30 quadrangles and 1 synoptic map). The surface of Mars is heterogeneous and is modified by wind, water, volcanism, tectonism, mass wasting and other processes. Surficial mapping identifies areas modified by these processes on a regional basis. Viking I mission results indicate that, at least in the landing site area, the surficial mapping based on Mariner data is fairly accurate. This area was mapped as a lightly cratered plain with thin or discontinuous eolian sediment. Analysis of lander images indicates that this interpretation is very close to actual surface conditions. These initial results do not imply that all surficial units are mapped correctly, but they do increase confidence in estimates based on photogeologic interpretations of orbital pictures.

Bi-scale analysis of multitemporal land cover fractions for wetland vegetation mapping

NASA Astrophysics Data System (ADS)

Michishita, Ryo; Jiang, Zhiben; Gong, Peng; Xu, Bing

2012-08-01

Land cover fractions (LCFs) derived through spectral mixture analysis are useful in understanding sub-pixel information. However, few studies have been conducted on the analysis of time-series LCFs. Although multi-scale comparisons of spectral index, hard classification, and land surface temperature images have received attention, rarely have these approaches been applied to LCFs. This study compared the LCFs derived through Multiple Endmember Spectral Mixture Analysis (MESMA) using the time-series Landsat Thematic Mapper (TM) and Terra Moderate Resolution Imaging Spectroradiometer (MODIS) data acquired in the Poyang Lake area, China between 2004 and 2005. Specifically, we aimed to: (1) propose an approach for optimal endmember (EM) selection in time-series MESMA; (2) understand the trends in time-series LCFs derived from the TM and MODIS data; and (3) examine the trends in the correlation between the bi-scale LCFs derived from the time-series TM and MODIS data. Our results indicated: (1) the EM spectra chosen according to the proposed hierarchical three-step approach (overall, seasonal, and individual) accurately modeled the both the TM and MODIS images; (2) green vegetation (GV) and NPV/soil/impervious surface (N/S/I) classes followed sine curve trends in the overall area, while the two water classes displayed the water level change pattern in the areas primarily covered with wetland vegetation; and (3) GV, N/S/I, and bright water classes indicated a moderately high agreement between the TM and MODIS LCFs in the whole area (adjusted R2 ⩾ 0.6). However, low levels of correlations were found in the areas primarily dominated by wetland vegetation for all land cover classes.

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.

Optical surface properties and their RF limitations of European XFEL cavities

NASA Astrophysics Data System (ADS)

Wenskat, Marc

2017-10-01

The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. The industrial fabrication of cavities for the European X-ray Free Electron Laser and the International Linear Collider HiGrade Research Project allowed for an investigation of this interplay. For the serial inspection of the inner surface, the optical inspection robot ’optical bench for automated cavity inspection with high resolution on short timescales’ OBACHT was constructed and to analyze the large amount of data, represented in the images of the inner surface, an image processing and analysis code was developed and new variables to describe the cavity surface were obtained. This quantitative analysis identified vendor-specific surface properties which allow the performance of quality control and assurance during production. In addition, a strong negative correlation of ρ =-0.93 with a significance of 6 σ of the integrated grain boundary area \\sum {A} versus the maximal achievable accelerating field {{E}}{acc,\\max } has been found.

Simulation of the shallow groundwater-flow system in the Forest County Potawatomi Community, Forest County, Wisconsin

USGS Publications Warehouse

Fienen, Michael N.; Saad, David A.; Juckem, Paul F.

2013-01-01

The shallow groundwater system in the Forest County Potawatomi Comminity, Forest County, Wisconsin, was simulated by expanding and recalibrating a previously calibrated regional model. The existing model was updated using newly collected water-level measurements, inclusion of surface-water features beyond the previous near-field boundary, and refinements to surface-water features. The updated model then was used to calculate the area contributing recharge for seven existing and three proposed pumping locations on lands of the Forest County Potawatomi Community. The existing wells were the subject of a 2004 source-water evaluation in which areas contributing recharge were calculated using the fixed-radius method. The motivation for the present (2012) project was to improve the level of detail of areas contributing recharge for the existing wells and to provide similar analysis for the proposed wells. Delineated 5- and 10-year areas contributing recharge for existing and proposed wells extend from the areas of pumping to delineate the area at the surface contributing recharge to the wells. Steady-state pumping was simulated for two scenarios: a base-pumping scenario using pumping rates that reflect what the Community currently (2012) pumps (or plans to in the case of proposed wells), and a high-pumping scenario in which the rate was set to the maximum expected from wells installed in this area, according to the Forest County Potawatomi Community Natural Resources Department. In general, the 10-year areas contributing recharge did not intersect surface-water bodies. The 5- and 10-year areas contributing recharge simulated at the maximum pumping rate at Bug Lake Road may intersect Bug Lake. At the casino near the Town of Carter, Wisconsin, the 10-year areas contributing recharge intersect infiltration ponds. At the Devils Lake and Lois Crow Drive wells, areas contributing recharge are near cultural features, including residences.

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

Delineation of marine ecosystem zones in the northern Arabian Sea during winter

NASA Astrophysics Data System (ADS)

Shalin, Saleem; Samuelsen, Annette; Korosov, Anton; Menon, Nandini; Backeberg, Björn C.; Pettersson, Lasse H.

2018-03-01

The spatial and temporal variability of marine autotrophic abundance, expressed as chlorophyll concentration, is monitored from space and used to delineate the surface signature of marine ecosystem zones with distinct optical characteristics. An objective zoning method is presented and applied to satellite-derived Chlorophyll a (Chl a) data from the northern Arabian Sea (50-75° E and 15-30° N) during the winter months (November-March). Principal component analysis (PCA) and cluster analysis (CA) were used to statistically delineate the Chl a into zones with similar surface distribution patterns and temporal variability. The PCA identifies principal components of variability and the CA splits these into zones based on similar characteristics. Based on the temporal variability of the Chl a pattern within the study area, the statistical clustering revealed six distinct ecological zones. The obtained zones are related to the Longhurst provinces to evaluate how these compared to established ecological provinces. The Chl a variability within each zone was then compared with the variability of oceanic and atmospheric properties viz. mixed-layer depth (MLD), wind speed, sea-surface temperature (SST), photosynthetically active radiation (PAR), nitrate and dust optical thickness (DOT) as an indication of atmospheric input of iron to the ocean. The analysis showed that in all zones, peak values of Chl a coincided with low SST and deep MLD. The rate of decrease in SST and the deepening of MLD are observed to trigger the algae bloom events in the first four zones. Lagged cross-correlation analysis shows that peak Chl a follows peak MLD and SST minima. The MLD time lag is shorter than the SST lag by 8 days, indicating that the cool surface conditions might have enhanced mixing, leading to increased primary production in the study area. An analysis of monthly climatological nitrate values showed increased concentrations associated with the deepening of the mixed layer. The input of iron seems to be important in both the open-ocean and coastal areas of the northern and north-western parts of the northern Arabian Sea, where the seasonal variability of the Chl a pattern closely follows the variability of iron deposition.

Mitigating the surface urban heat island: Mechanism study and sensitivity analysis

NASA Astrophysics Data System (ADS)

Meng, Chunlei

2017-08-01

In a surface urban heat island (SUHI), the urban land surface temperature (LST) is usually higher than the temperature of the surrounding rural areas due to human activities and surface characteristics. Because a SUHI has many adverse impacts on urban environment and human health, SUHI mitigation strategies are very important. This paper investigates the mechanism of a SUHI based on the basic physical laws that control the formation of a SUHI; five mitigation strategies are proposed, namely: sprinkling and watering; paving a pervious surface; reducing the anthropogenic heat (AH) release; using a "white roof"; increasing the fractional vegetation cover or leaf area index (LAI). To quantify the effect of these mitigation strategies, 26 sets of experiments are designed and implemented by running the integrated urban land model (IUM). The results of the sensitivity analysis indicate that sprinkling and watering is an effective measure for mitigating a SUHI for an entire day. Decreasing the AH release is also useful for both night- and daytime SUHI mitigation; however, the cooling extent is proportional to the diurnal cycle of AH. Increasing the albedo can reduce the LST in the daytime, especially when the solar radiation is significant; the cooling extent is approximately proportional to the diurnal cycle of the net radiation. Increasing the pervious surface percentage can mitigate the SUHI especially in the daytime. Increasing the fractional vegetation cover can mitigate the SUHI in the daytime but may aggravate the SUHI at night.

Biopolymer protected silver nanoparticles on the support of carbon nanotube as interface for electrocatalytic applications

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

Satyanarayana, M.; Kumar, V. Sunil; Gobi, K. Vengatajalabathy, E-mail: drkvgobi@gmail.com, E-mail: satyam.nitw@gmail.com

In this research, silver nanoparticles (SNPs) are prepared on the surface of carbon nanotubes via chitosan, a biopolymer linkage. Here chitosan act as stabilizing agent for nanoparticles and forms a network on the surface of carbon nanotubes. Synthesized silver nanoparticles-MWCNT hybrid composite is characterized by UV-Visible spectroscopy, XRD analysis, and FESEM with EDS to evaluate the structural and chemical properties of the nanocomposite. The electrocatalytic activity of the fabricated SNP-MWCNT hybrid modified glassy carbon electrode has been evaluated by cyclic voltammetry and electrochemical impedance analysis. The silver nanoparticles are of size ∼35 nm and are well distributed on the surface ofmore » carbon nanotubes with chitosan linkage. The prepared nanocomposite shows efficient electrocatalytic properties with high active surface area and excellent electron transfer behaviour.« less

Laser confocal microscope for analysis of 3013 inner container closure weld region

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

Martinez-Rodriguez, M. J.

As part of the protocol to investigate the corrosion in the inner container closure weld region (ICCWR) a laser confocal microscope (LCM) was used to perform close visual examination of the surface and measurements of corrosion features on the surface. However, initial analysis of selected destructively evaluated (DE) containers using the LCM revealed several challenges for acquiring, processing and interpreting the data. These challenges include topography of the ICCWR sample, surface features, and the amount of surface area for collecting data at high magnification conditions. In FY17, the LCM parameters were investigated to identify the appropriate parameter values for datamore » acquisition and identification of regions of interest. Using these parameter values, selected DE containers were analyzed to determine the extent of the ICCWR to be examined.« less

A comparative evaluation of the increase in root canal surface area and canal transportation in curved root canals by three rotary systems: A cone-beam computed tomographic study

PubMed Central

Prasanthi, Nalam NVD; Rambabu, Tanikonda; Sajjan, Girija S; Varma, K Madhu; Satish, R Kalyan; Padmaja, M

2016-01-01

Aim: The aim of this study was to measure the increase in root canal surface area and canal transportation after biomechanical preparation at 1, 3, and 5 mm short of the apex with three different rotary systems in both continuous rotary and reciprocating rotary motions. Materials and Methods: Sixty freshly extracted human mandibular molars with mesial root canal curvatures between 20° and 30° were included in the study. Teeth were randomly distributed into three groups (n = 20). Biomechanical preparations were done in all the mesial canals. In Group 1, instrumentation was done with ProTaper universal rotary files, Group 2, with K3XF rotary files, and Group 3, with LSX rotary files. Each group was further subdivided into subgroups A and B (n = 10) where instrumentation was done by continuous rotary and reciprocating rotary techniques, respectively. Increase in root canal surface area and canal transportation was measured using the preoperative and postoperative cone-beam computed tomography scans. Statistical Analysis: The data were analyzed by one-way ANOVA followed by Tukey pairwise multiple comparison tests. Results: Increase in root canal surface area was significantly more (P < 0.05) in ProTaper and K3XF groups when compared to LSX group. Canal transportation was significantly more (P < 0.05) in ProTaper group when compared to K3XF and LSX groups. There was no significant difference (P > 0.05) in increase of root canal surface area and canal transportation between continuous rotary and reciprocating rotary techniques for ProTaper Universal, K3XF and LSX groups. Conclusion: LSX rotary system showed minimal increase of root canal surface area and minimal canal transportation when compared to ProTaper and K3XF rotary systems. PMID:27656062

A high surface area Zr(IV)-based metal–organic framework showing stepwise gas adsorption and selective dye uptake

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

Lv, Xiu-Liang; Tong, Minman; Huang, Hongliang

2015-03-15

Exploitation of new metal–organic framework (MOF) materials with high surface areas has been attracting great attention in related research communities due to their broad potential applications. In this work, a new Zr(IV)-based MOF, [Zr{sub 6}O{sub 4}(OH){sub 4}(eddb){sub 6}] (BUT-30, H{sub 2}eddb=4,4′-(ethyne-1,2-diyl)dibenzoic acid) has been solvothermally synthesized, characterized, and explored for gases and dyes adsorptions. Single-crystal X-ray diffraction analysis demonstrates a three-dimensional cubic framework structure of this MOF, in which each Zr{sub 6}O{sub 4}(OH){sub 4} building unit is linked by 12 linear eddb ligands. BUT-30 has been found stable up to 400 °C and has a Brunauer–Emmett–Teller (BET) surface area asmore » high as 3940.6 m{sup 2} g{sup −1} (based on the N{sub 2} adsorption at 77 K) and total pore volume of 1.55 cm{sup 3} g{sup −1}. It is more interesting that this MOF exhibits stepwise adsorption behaviors for Ar, N{sub 2}, and CO{sub 2} at low temperatures, and selective uptakes towards different ionic dyes. - Graphical abstract: A new Zr(IV)-based MOF with high surface area has been synthesized and structurally characterized, which shows stepwise gas adsorption at low temperature and selective dye uptake from solution. - Highlights: • A new Zr-based MOF was synthesized and structurally characterized. • This MOF shows a higher surface area compared with its analogous UiO-67 and 68. • This MOF shows a rare stepwise adsorption towards light gases at low temperature. • This MOF performs selective uptakes towards cationic dyes over anionic ones. • Using triple-bond spacer is confirmed feasible in enhancing MOF surface areas.« less

Aquifer configuration and geostructural links control the groundwater quality in thin-bedded carbonate-siliciclastic alternations of the Hainich CZE, central Germany

NASA Astrophysics Data System (ADS)

Kohlhepp, Bernd; Lehmann, Robert; Seeber, Paul; Küsel, Kirsten; Trumbore, Susan E.; Totsche, Kai U.

2017-12-01

The quality of near-surface groundwater reservoirs is controlled, but also threatened, by manifold surface-subsurface interactions. Vulnerability studies typically evaluate the variable interplay of surface factors (land management, infiltration patterns) and subsurface factors (hydrostratigraphy, flow properties) in a thorough way, but disregard the resulting groundwater quality. Conversely, hydrogeochemical case studies that address the chemical evolution of groundwater often lack a comprehensive analysis of the structural buildup. In this study, we aim to reconstruct the actual spatial groundwater quality pattern from a synoptic analysis of the hydrostratigraphy, lithostratigraphy, pedology and land use in the Hainich Critical Zone Exploratory (Hainich CZE). This CZE represents a widely distributed yet scarcely described setting of thin-bedded mixed carbonate-siliciclastic strata in hillslope terrains. At the eastern Hainich low-mountain hillslope, bedrock is mainly formed by alternated marine sedimentary rocks of the Upper Muschelkalk (Middle Triassic) that partly host productive groundwater resources. Spatial patterns of the groundwater quality of a 5.4 km long well transect are derived by principal component analysis and hierarchical cluster analysis. Aquifer stratigraphy and geostructural links were deduced from lithological drill core analysis, mineralogical analysis, geophysical borehole logs and mapping data. Maps of preferential recharge zones and recharge potential were deduced from digital (soil) mapping, soil survey data and field measurements of soil hydraulic conductivities (Ks). By attributing spatially variable surface and subsurface conditions, we were able to reconstruct groundwater quality clusters that reflect the type of land management in their preferential recharge areas, aquifer hydraulic conditions and cross-formational exchange via caprock sinkholes or ascending flow. Generally, the aquifer configuration (spatial arrangement of strata, valley incision/outcrops) and related geostructural links (enhanced recharge areas, karst phenomena) control the role of surface factors (input quality and locations) vs. subsurface factors (water-rock interaction, cross-formational flow) for groundwater quality in the multi-layered aquifer system. Our investigation reveals general properties of alternating sequences in hillslope terrains that are prone to forming multi-layered aquifer systems. This synoptic analysis is fundamental and indispensable for a mechanistic understanding of ecological functioning, sustainable resource management and protection.

Use of Several Thermal Analysis Techniques to Study the Cracking of an Nitrile Butadiene Rubber (NBR) Insulator on the Booster Separation Motor (BSM) of the Space Shuttle

NASA Technical Reports Server (NTRS)

Wingard, Charles D.; Whitaker, Ann F. (Technical Monitor)

2000-01-01

Two different vendor rubber formulations have been used to produce the silica-filled NBR insulators for the BSM used on both of the Solid Rocket Boosters (SRBs) of the Space Shuttle. A number of lots of the BSM insulator in 1998-99 exhibited surface cracks and/or crazing. Each insulator is bonded to the BSM aluminum aft closure with an epoxy adhesive. Induced insulator stresses from adhesive cure are likely greatest where the insulator/adhesive contour is the greatest, thus showing increased insulator surface cracking in this area. Thermal analysis testing by Dynamic Mechanical Analyzer (DMA) and Thermomechanical Analysis (TMA) was performed on one each of the two vendor BSM insulators previously bonded that exhibited the surface cracking. The TMA data from the film/fiber technique yielded the most meaningful results, with thin insulator surface samples containing cracks having roughly the same modulus (stiffness) as thin insulator bulk samples just underneath.

Spatial scale analysis in geophysics - Integrating surface and borehole geophysics in groundwater studies

USGS Publications Warehouse

Paillet, Frederick L.; Singhroy, V.H.; Hansen, D.T.; Pierce, R.R.; Johnson, A.I.

2002-01-01

Integration of geophysical data obtained at various scales can bridge the gap between localized data from boreholes and site-wide data from regional survey profiles. Specific approaches to such analysis include: 1) comparing geophysical measurements in boreholes with the same measurement made from the surface; 2) regressing geophysical data obtained in boreholes with water-sample data from screened intervals; 3) using multiple, physically independent measurements in boreholes to develop multivariate response models for surface geophysical surveys; 4) defining subsurface cell geometry for most effective survey inversion methods; and 5) making geophysical measurements in boreholes to serve as independent verification of geophysical interpretations. Integrated analysis of surface electromagnetic surveys and borehole geophysical logs at a study site in south Florida indicates that salinity of water in the surficial aquifers is controlled by a simple wedge of seawater intrusion along the coast and by a complex pattern of upward brine seepage from deeper aquifers throughout the study area. This interpretation was verified by drilling three additional test boreholes in carefully selected locations.

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.

Application of classification methods for mapping Mercury's surface composition: analysis on Rudaki's Area

NASA Astrophysics Data System (ADS)

Zambon, F.; De Sanctis, M. C.; Capaccioni, F.; Filacchione, G.; Carli, C.; Ammanito, E.; Friggeri, A.

2011-10-01

During the first two MESSENGER flybys (14th January 2008 and 6th October 2008) the Mercury Dual Imaging System (MDIS) has extended the coverage of the Mercury surface, obtained by Mariner 10 and now we have images of about 90% of the Mercury surface [1]. MDIS is equipped with a Narrow Angle Camera (NAC) and a Wide Angle Camera (WAC). The NAC uses an off-axis reflective design with a 1.5° field of view (FOV) centered at 747 nm. The WAC has a re- fractive design with a 10.5° FOV and 12-position filters that cover a 395-1040 nm spectral range [2]. The color images can be used to infer information on the surface composition and classification meth- ods are an interesting technique for multispectral image analysis which can be applied to the study of the planetary surfaces. Classification methods are based on clustering algorithms and they can be divided in two categories: unsupervised and supervised. The unsupervised classifiers do not require the analyst feedback, and the algorithm automatically organizes pixels values into classes. In the supervised method, instead, the analyst must choose the "training area" that define the pixels value of a given class [3]. Here we will describe the classification in different compositional units of the region near the Rudaki Crater on Mercury.

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.

Pd/Cu-Oxide Nanoconjugate at Zeolite-Y Crystallite Crafting the Mesoporous Channels for Selective Oxidation of Benzyl-Alcohols.

PubMed

Sharma, Mukesh; Das, Biraj; Sharma, Mitu; Deka, Biplab K; Park, Young-Bin; Bhargava, Suresh K; Bania, Kusum K

2017-10-11

Solid-state grinding of palladium and copper salts allowed the growth of palladium/copper oxide interface at the zeolite-Y surface. The hybrid nanostructured material was used as reusable heterogeneous catalyst for selective oxidation of various benzyl alcohols. The large surface area provided by the zeolite-Y matrix highly influenced the catalytic activity, as well as the recyclability of the synthesized catalyst. Impregnation of PdO-CuO nanoparticles on zeolite crystallite leads to the generation of mesoporous channel that probably prevented the leaching of the metal-oxide nanoparticles and endorsed high mass transfer. Formation of mesoporous channel at the external surface of zeolite-Y was evident from transmission electron microscopy and surface area analysis. PdO-CuO nanoparticles were found to be within the range of 2-5 nm. The surface area of PdO-CuO-Y catalyst was found to be much lower than parent zeolite-Y. The decrease in surface area as well as the presence of hysteresis loop in the N 2 -adsoprtion isotherm further suggested successful encapsulation of PdO-CuO nanoparticles via the mesoporous channel formation. The high positive shifting in binding energy in both Pd and Cu was attributed to the influence of zeolite-Y framework on lattice contraction of metal oxides via confinement effect. PdO-CuO-Y catalyst was found to oxidize benzyl alcohol with 99% selectivity. On subjecting to microwave irradiation the same oxidation reaction was found to occur at ambient condition giving same conversion and selectivity.

Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

NASA Astrophysics Data System (ADS)

Yu, Liang; Rozemeijer, Joachim; van Breukelen, Boris M.; Ouboter, Maarten; van der Vlugt, Corné; Broers, Hans Peter

2018-01-01

The Amsterdam area, a highly manipulated delta area formed by polders and reclaimed lakes, struggles with high nutrient levels in its surface water system. The polders receive spatially and temporally variable amounts of water and nutrients via surface runoff, groundwater seepage, sewer leakage, and via water inlets from upstream polders. Diffuse anthropogenic sources, such as manure and fertiliser use and atmospheric deposition, add to the water quality problems in the polders. The major nutrient sources and pathways have not yet been clarified due to the complex hydrological system in lowland catchments with both urban and agricultural areas. In this study, the spatial variability of the groundwater seepage impact was identified by exploiting the dense groundwater and surface water monitoring networks in Amsterdam and its surrounding polders. A total of 25 variables (concentrations of total nitrogen (TN), total phosphorus (TP), NH4, NO3, HCO3, SO4, Ca, and Cl in surface water and groundwater, N and P agricultural inputs, seepage rate, elevation, land-use, and soil type) for 144 polders were analysed statistically and interpreted in relation to sources, transport mechanisms, and pathways. The results imply that groundwater is a large source of nutrients in the greater Amsterdam mixed urban-agricultural catchments. The groundwater nutrient concentrations exceeded the surface water environmental quality standards (EQSs) in 93 % of the polders for TP and in 91 % for TN. Groundwater outflow into the polders thus adds to nutrient levels in the surface water. High correlations (R2 up to 0.88) between solutes in groundwater and surface water, together with the close similarities in their spatial patterns, confirmed the large impact of groundwater on surface water chemistry, especially in the polders that have high seepage rates. Our analysis indicates that the elevated nutrient and bicarbonate concentrations in the groundwater seepage originate from the decomposition of organic matter in subsurface sediments coupled to sulfate reduction and possibly methanogenesis. The large loads of nutrient-rich groundwater seepage into the deepest polders indirectly affect surface water quality in the surrounding area, because excess water from the deep polders is pumped out and used to supply water to the surrounding infiltrating polders in dry periods. The study shows the importance of the connection between groundwater and surface water nutrient chemistry in the greater Amsterdam area. We expect that taking account of groundwater-surface water interaction is also important in other subsiding and urbanising deltas around the world, where water is managed intensively in order to enable agricultural productivity and achieve water-sustainable cities.

Classification and analysis of the Rudaki's Area

NASA Astrophysics Data System (ADS)

Zambon, F.; De sanctis, M.; Capaccioni, F.; Filacchione, G.; Carli, C.; Ammannito, E.; Frigeri, A.

2011-12-01

During the first two MESSENGER flybys the Mercury Dual Imaging System (MDIS) has mapped 90% of the Mercury's surface. An effective way to study the different terrain on planetary surfaces is to apply classification methods. These are based on clustering algorithms and they can be divided in two categories: unsupervised and supervised. The unsupervised classifiers do not require the analyst feedback and the algorithm automatically organizes pixels values into classes. In the supervised method, instead, the analyst must choose the "training area" that define the pixels value of a given class. We applied an unsupervised classifier, ISODATA, to the WAC filter images of the Rudaki's area where several kind of terrain have been identified showing differences in albedo, topography and crater density. ISODATA classifier divides this region in four classes: 1) shadow regions, 2) rough regions, 3) smooth plane, 4) highest reflectance area. ISODATA can not distinguish the high albedo regions from highly reflective illuminated edge of the craters, however the algorithm identify four classes that can be considered different units mainly on the basis of their reflectances at the various wavelengths. Is not possible, instead, to extrapolate compositional information because of the absence of clear spectral features. An additional analysis was made using ISODATA to choose the "training area" for further supervised classifications. These approach would allow, for example, to separate more accurately the edge of the craters from the high reflectance areas and the low reflectance regions from the shadow areas.