Hand burns surface area: A rule of thumb.

Science.gov (United States)

Dargan, Dallan; Mandal, Anirban; Shokrollahi, Kayvan

2018-03-11

Rapid estimation of acute hand burns is important for communication, standardisation of assessment, rehabilitation and research. Use of an individual's own thumbprint area as a fraction of their total hand surface area was evaluated to assess potential utility in hand burn evaluation. Ten health professionals used an ink-covered dominant thumb pulp to cover the surfaces of their own non-dominant hand using the contralateral thumb. Thumbprints were assessed on the web spaces, sides of digits and dorsum and palm beyond the distal wrist crease. Hand surface area was estimated using the Banerjee and Sen method, and thumbprint ellipse area calculated to assess correlation. Mean estimated total hand surface area was 390.0cm 2 ±SD 51.5 (328.3-469.0), mean thumbprint ellipse area was 5.5cm 2 ±SD 1.3 (3.7-8.4), and mean estimated print number was 73.5±SD 11.0 (range 53.1-87.8, 95% CI 6.8). The mean observed number of thumbprints on one hand was 80.1±SD 5.9 (range 70.0-88.0, 95% CI 3.7), χ 2 =0.009. The combined mean of digital prints was 42, comprising a mean of two prints each on volar, dorsal, radial and ulnar digit surfaces, except volar middle and ring (3 prints each). Palmar prints were 15 (11-19), dorsal 15 (11-19), ulnar palm border 3, first web space 2, and second, third and fourth web spaces one each. Using the surface of the palm alone, excluding digits, as 0.5% of total body surface area, the area of one thumbprint was approximated as 1/30th of 1%. We have demonstrated how thumbprint area serves as a simple method for evaluating hand burn surface area. Copyright © 2018 Elsevier Ltd and ISBI. All rights reserved.

Geomorphological and hydrological transformation of the landscape due to mining activity in the mining area Bana Dolina

International Nuclear Information System (INIS)

Balga, J.; Hroncova, E.

2010-01-01

After more than 150 year history of mining activity in the brown coal mining area Bana Dolina have been produced a range of anthropogenic forms of relief. For reasons of underground coal mining to make interventions in the hydrographic network. Significant changes due to surface mining of coal seams should result in subsidence basins of different sizes, damage to buildings and roads. Mining activity was influenced by agricultural and forestry fund, gardening settlements. All these factors have contributed to the change in relief of the surrounding area. This study aims to research the effects of the largest mining Bana Dolina mining area reflecting the structure of land area. (authors)

Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

Energy Technology Data Exchange (ETDEWEB)

Serra, R., E-mail: ricardo.serra@dem.uc.pt [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Oliveira, V. [ICEMS-Instituto de Ciência e Engenharia de Materiais e Superfícies, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Oliveira, J.C. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal); Kubart, T. [The Ångström Laboratory, Solid State Electronics, P.O. Box 534, SE-751 21 Uppsala (Sweden); Vilar, R. [Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro Emídio Navarro no 1, 1959-007 Lisbon (Portugal); Instituto Superior Técnico, Avenida Rovisco Pais no 1, 1049-001 Lisbon (Portugal); Cavaleiro, A. [SEG-CEMUC, Mechanical Engineering Department, University of Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra (Portugal)

2015-03-15

Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm{sup 2}. Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under

Large-area homogeneous periodic surface structures generated on the surface of sputtered boron carbide thin films by femtosecond laser processing

International Nuclear Information System (INIS)

Serra, R.; Oliveira, V.; Oliveira, J.C.; Kubart, T.; Vilar, R.; Cavaleiro, A.

2015-01-01

Highlights: • Large-area LIPSS were formed by femtosecond laser processing B-C films surface. • The LIPSS spatial period increases with laser fluence (140–200 nm). • Stress-related sinusoidal-like undulations were formed on the B-C films surface. • The undulations amplitude (down to a few nanometres) increases with laser fluence. • Laser radiation absorption increases with surface roughness. - Abstract: Amorphous and crystalline sputtered boron carbide thin films have a very high hardness even surpassing that of bulk crystalline boron carbide (≈41 GPa). However, magnetron sputtered B-C films have high friction coefficients (C.o.F) which limit their industrial application. Nanopatterning of materials surfaces has been proposed as a solution to decrease the C.o.F. The contact area of the nanopatterned surfaces is decreased due to the nanometre size of the asperities which results in a significant reduction of adhesion and friction. In the present work, the surface of amorphous and polycrystalline B-C thin films deposited by magnetron sputtering was nanopatterned using infrared femtosecond laser radiation. Successive parallel laser tracks 10 μm apart were overlapped in order to obtain a processed area of about 3 mm 2 . Sinusoidal-like undulations with the same spatial period as the laser tracks were formed on the surface of the amorphous boron carbide films after laser processing. The undulations amplitude increases with increasing laser fluence. The formation of undulations with a 10 μm period was also observed on the surface of the crystalline boron carbide film processed with a pulse energy of 72 μJ. The amplitude of the undulations is about 10 times higher than in the amorphous films processed at the same pulse energy due to the higher roughness of the films and consequent increase in laser radiation absorption. LIPSS formation on the surface of the films was achieved for the three B-C films under study. However, LIPSS are formed under different

Estimating surface area in early hominins.

Directory of Open Access Journals (Sweden)

Alan Cross

Full Text Available Height and weight-based methods of estimating surface area have played an important role in the development of the current consensus regarding the role of thermoregulation in human evolution. However, such methods may not be reliable when applied to early hominins because their limb proportions differ markedly from those of humans. Here, we report a study in which this possibility was evaluated by comparing surface area estimates generated with the best-known height and weight-based method to estimates generated with a method that is sensitive to proportional differences. We found that the two methods yield indistinguishable estimates when applied to taxa whose limb proportions are similar to those of humans, but significantly different results when applied to taxa whose proportions differ from those of humans. We also found that the discrepancy between the estimates generated by the two methods is almost entirely attributable to inter-taxa differences in limb proportions. One corollary of these findings is that we need to reassess hypotheses about the role of thermoregulation in human evolution that have been developed with the aid of height and weight-based methods of estimating body surface area. Another is that we need to use other methods in future work on fossil hominin body surface areas.

A Simple Proof of Cauchy's Surface Area Formula

OpenAIRE

Tsukerman, Emmanuel; Veomett, Ellen

2016-01-01

We give a short and simple proof of Cauchy's surface area formula, which states that the average area of a projection of a convex body is equal to its surface area up to a multiplicative constant in the dimension.

Quantifying object and material surface areas in residences

Energy Technology Data Exchange (ETDEWEB)

Hodgson, Alfred T.; Ming, Katherine Y.; Singer, Brett C.

2005-01-05

The dynamic behavior of volatile organic compounds (VOCs) in indoor environments depends, in part, on sorptive interactions between VOCs in the gas phase and material surfaces. Since information on the types and quantities of interior material surfaces is not generally available, this pilot-scale study was conducted in occupied residences to develop and demonstrate a method for quantifying surface areas of objects and materials in rooms. Access to 33 rooms in nine residences consisting of bathrooms, bedroom/offices and common areas was solicited from among research group members living in the East San Francisco Bay Area. A systematic approach was implemented for measuring rooms and objects from 300 cm{sup 2} and larger. The ventilated air volumes of the rooms were estimated and surface area-to-volume ratios were calculated for objects and materials, each segregated into 20 or more categories. Total surface area-to-volume ratios also were determined for each room. The bathrooms had the highest total surface area-to-volume ratios. Bedrooms generally had higher ratios than common areas consisting of kitchens, living/dining rooms and transitional rooms. Total surface area-to-volume ratios for the 12 bedrooms ranged between 2.3 and 4.7 m{sup 2} m{sup -3}. The importance of individual objects and materials with respect to sorption will depend upon the sorption coefficients for the various VOC/materials combinations. When combined, the highly permeable material categories, which may contribute to significant interactions, had a median ratio of about 0.5 m{sup 2} m{sup -3} for all three types of rooms.

Quantification of lung surface area using computed tomography

Directory of Open Access Journals (Sweden)

Xing Li

2010-10-01

Full Text Available Abstract Objective To refine the CT prediction of emphysema by comparing histology and CT for specific regions of lung. To incorporate both regional lung density measured by CT and cluster analysis of low attenuation areas for comparison with histological measurement of surface area per unit lung volume. Methods The histological surface area per unit lung volume was estimated for 140 samples taken from resected lung specimens of fourteen subjects. The region of the lung sampled for histology was located on the pre-operative CT scan; the regional CT median lung density and emphysematous lesion size were calculated using the X-ray attenuation values and a low attenuation cluster analysis. Linear mixed models were used to examine the relationships between histological surface area per unit lung volume and CT measures. Results The median CT lung density, low attenuation cluster analysis, and the combination of both were important predictors of surface area per unit lung volume measured by histology (p Conclusion Combining CT measures of lung density and emphysematous lesion size provides a more accurate estimate of lung surface area per unit lung volume than either measure alone.

An empirical method for estimating surface area of aggregates in hot mix asphalt

Directory of Open Access Journals (Sweden)

R.P. Panda

2016-04-01

Full Text Available Bitumen requirement in hot mix asphalt (HMA is directly dependent on the surface area of the aggregates in the mix, which in turn has effect on the asphalt film thickness and the flow characteristics. The surface area of aggregate blend in HMA is calculated using the specific surface area factors assigned to percentage passing through some specific standard sieve sizes and the imaging techniques. The first process is less capital intensive, but purely manual and labour intensive and prone to human errors. Imaging techniques though eliminating the human errors, still have limited use due to capital intensiveness and requirement of well-established laboratories with qualified technicians. Most of the developing countries like India are shortage of well-equipped laboratories and qualified technicians. To overcome these difficulties, the present mathematical model has been developed to estimate the surface area of aggregate blend of HMA from physical properties of aggregates evaluated using simple laboratory equipment. This model has been validated compared with the existing established methods of calculations and can be used as one of the tools in different developing and under developed countries for proper design of HMA.

Verification of surface source's characteristics using large-area 2π gas flow counter

International Nuclear Information System (INIS)

Abu Naser Waheed, M.M.; Mikami, S.; Kobayashi, H.; Noda, K.

1998-09-01

Power Reactor and Nuclear Fuel Development Corporation (PNC) has large-area 2π gas flow counter for the purpose of measuring activity of surface sources of alpha or beta ray emitter. Surface sources are used for the calibration of radiation measuring equipment for radiation control. Due to sequent use of sources, the surface of these sources are inclined to go in bad condition because of unwanted accidental incidents. For the better calibration achievement of radiation measuring instruments the rate of emission of these sources are to be checked periodically by the large-area 2π gas flow counter. In this paper described that eight U 3 O 8 surface sources were selected from many sources of PNC Tokai Works and activity of these sources was measured by the 2π gas flow counter. The results were compared with the values certified by Japan Radio Isotope Association (JRIA). It is evident from the result of comparison that the surface sources are in good condition, i.e., the sources are reliable to calibrate the radiation control instruments. (author)

Area densitometry using rotating Scheimpflug photography for posterior capsule opacification and surface light scattering analyses.

Science.gov (United States)

Minami, Keiichiro; Honbo, Masato; Mori, Yosai; Kataoka, Yasushi; Miyata, Kazunori

2015-11-01

To compare area densitometry analysis using rotating Scheimpflug photography in quantifications of posterior capsule opacification (PCO) and surface light scattering with previous anterior-segment analyzer measurement. Miyata Eye Hospital, Miyazaki, Japan. Prospective observational case series. Scheimpflug images of eyes with foldable intraocular lenses (IOLs) were obtained using rotating and fixed Scheimpflug photography. Area densitometry on the posterior and anterior surfaces was conducted for PCO and surface light scattering analyses, respectively, with an identical area size. Correlation between two measurements was analyzed using linear regression. The study included 105 eyes of 74 patients who received IOLs 1 to 18 years (mean, 4.9 ± 4.5 years) postoperatively. In the PCO analysis on the posterior IOL surface, there was a significant correlation between the two measurements (P photography exhibited saturation due to intensive scatterings. Area densitometry combined with a rotating Scheimpflug photography was exchangeable to previously established densitometry measurement, and allowed successive evaluation in longer-term observations. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Surface area considerations for corroding N reactor fuel

International Nuclear Information System (INIS)

Johnson, A.B. Jr.; Pitner, A.L.

1996-06-01

The N Reactor fuel is corroding at sites where the Zircaloy cladding was damaged when the fuel was discharged from the reactor. Corroding areas are clearly visible on the fuel stored in open cans in the K East Basin. There is a need to estimate the area of the corroding uranium to analyze aspects of fuel behavior as it is transitioned. from current wet storage to dry storage. In this report, the factors that contribute to open-quotes trueclose quotes surface area are analyzed in terms of what is currently known about the N Reactor fuel. Using observations from a visual examinations of the fuel in the K East wet storage facility, a value for the corroding geometric area is estimated. Based on observations of corroding uranium and surface roughness values for other metals, a surface roughness factor is also estimated and applied to the corroding K East fuel to provide an estimated open-quotes trueclose quotes surface area. While the estimated area may be modified as additional data become available from fuel characterization studies, the estimate provides a basis to assess effects of exposed uranium metal surfaces on fuel behavior in operations involved in transitioning from wet to dry storage, during shipment and staging, conditioning, and dry interim storage

High surface area carbon for bifunctional air electrodes applied in zinc-air batteries

Energy Technology Data Exchange (ETDEWEB)

Arai, H [on leave from NTT Laboratories (Japan); Mueller, S; Haas, O [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

Bifunctional air electrodes with high surface area carbon substrates showed low reduction overpotential, thus are promising for enhancing the energy efficiency and power capability of zinc-air batteries. The improved performance is attributed to lower overpotential due to diffusion of the reaction intermediate, namely the peroxide ion. (author) 1 fig., 2 refs.

Increased dose near the skin due to electromagnetic surface beacon transponder.

Science.gov (United States)

Ahn, Kang-Hyun; Manger, Ryan; Halpern, Howard J; Aydogan, Bulent

2015-05-08

The purpose of this study was to evaluate the increased dose near the skin from an electromagnetic surface beacon transponder, which is used for localization and tracking organ motion. The bolus effect due to the copper coil surface beacon was evaluated with radiographic film measurements and Monte Carlo simulations. Various beam incidence angles were evaluated for both 6 MV and 18 MV experimentally. We performed simulations using a general-purpose Monte Carlo code MCNPX (Monte Carlo N-Particle) to supplement the experimental data. We modeled the surface beacon geometry using the actual mass of the glass vial and copper coil placed in its L-shaped polyethylene terephthalate tubing casing. Film dosimetry measured factors of 2.2 and 3.0 enhancement in the surface dose for normally incident 6 MV and 18 MV beams, respectively. Although surface dose further increased with incidence angle, the relative contribution from the bolus effect was reduced at the oblique incidence. The enhancement factors were 1.5 and 1.8 for 6 MV and 18 MV, respectively, at an incidence angle of 60°. Monte Carlo simulation confirmed the experimental results and indicated that the epidermal skin dose can reach approximately 50% of the dose at dmax at normal incidence. The overall effect could be acceptable considering the skin dose enhancement is confined to a small area (~ 1 cm2), and can be further reduced by using an opposite beam technique. Further clinical studies are justified in order to study the dosimetric benefit versus possible cosmetic effects of the surface beacon. One such clinical situation would be intact breast radiation therapy, especially large-breasted women.

AN EXAMPLE IN SURFACE AREA*

Science.gov (United States)

Goffman, Casper

1969-01-01

For length and area, a central fact is that the value of the length of a curve or the area of a surface, as given by the Lebesgue theory, is at least as great as that given by the classical formula, whenever the latter has meaning. This is now found not to be valid in higher dimensions. We give an example of a continuous mapping of the unit cube into itself for which the value given by the formula exceeds the three-dimensional Lebesgue area of the corresponding suface. PMID:16591750

Effect of surface area of substrates aiming the optimization of carbon nanotube production from ferrocene

International Nuclear Information System (INIS)

Osorio, A.G.; Bergmann, C.P.

2013-01-01

Highlights: ► An optimized synthesis of CNTs by ferrocene is proposed. ► The surface area of substrates influences the nucleation of CNTs. ► The higher the surface area of substrates the lower the temperature of synthesis. ► Chemical composition of substrates has no influence on the growth of CNTs. - Abstract: Ferrocene is widely used for the synthesis of carbon nanotubes due to its ability to act as catalyst and precursor of the synthesis. This paper proposes an optimization of the synthesis of carbon nanotubes from ferrocene, using a substrate with high surface area for their nucleation. Four different surface areas of silica powder were tested: 0.5, 50, 200 and 300 m 2 /g. Raman spectroscopy and microscopy were used to characterize the product obtained and X-ray diffraction and thermal analysis were also performed to evaluate the phases of the material. It was observed that the silica powder with the highest surface area allowed the synthesis of carbon nanotubes to occur at a lower temperature (600 °C), whereas substrates with a surface area lower than 50 m 2 /g will only form carbon nanotubes at temperatures higher than 750 °C. In order to evaluate the influence of chemical composition of the substrate, three different ceramic powders were analyzed: alumina, silica and zirconia. carbon black and previously synthesized carbon nanotubes were also used as substrate for the synthesis and the results showed that the chemical composition of the substrate does not play a relevant role in the synthesis of carbon nanotubes, only the surface area showed an influence.

INTERNAL STRUCTURE OF ASTEROIDS HAVING SURFACE SHEDDING DUE TO ROTATIONAL INSTABILITY

Energy Technology Data Exchange (ETDEWEB)

Hirabayashi, Masatoshi [Research Associate, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States); Sánchez, Diego Paul [Senior Research Associate, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States); Scheeres, Daniel J., E-mail: masatoshi.hirabayashi@colorado.edu [Richard Seebass Chair, Professor, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States)

2015-07-20

Surface shedding of an asteroid is a failure mode where surface materials fly off due to strong centrifugal forces beyond the critical spin period, while the internal structure does not deform significantly. This paper proposes a possible structure of an asteroid interior that leads to surface shedding due to rapid rotation rates. A rubble pile asteroid is modeled as a spheroid composed of a surface shell and a concentric internal core, the entire assembly called the test body. The test body is assumed to be uniformly rotating around a constant rotation axis. We also assume that while the bulk density and the friction angle are constant, the cohesion of the surface shell is different from that of the internal core. First, developing an analytical model based on limit analysis, we provide the upper and lower bounds for the actual surface shedding condition. Second, we use a Soft-sphere Discrete Element Method (SSDEM) to study dynamical deformation of the test body due to a quasi-static spin-up. In this paper we show the consistency of both approaches. Additionally, the SSDEM simulations show that the initial failure always occurs locally and not globally. In addition, as the core becomes larger, the size of lofted components becomes smaller. These results imply that if there is a strong core in a progenitor body, surface shedding is the most likely failure mode.

INTERNAL STRUCTURE OF ASTEROIDS HAVING SURFACE SHEDDING DUE TO ROTATIONAL INSTABILITY

International Nuclear Information System (INIS)

Hirabayashi, Masatoshi; Sánchez, Diego Paul; Scheeres, Daniel J.

2015-01-01

Surface shedding of an asteroid is a failure mode where surface materials fly off due to strong centrifugal forces beyond the critical spin period, while the internal structure does not deform significantly. This paper proposes a possible structure of an asteroid interior that leads to surface shedding due to rapid rotation rates. A rubble pile asteroid is modeled as a spheroid composed of a surface shell and a concentric internal core, the entire assembly called the test body. The test body is assumed to be uniformly rotating around a constant rotation axis. We also assume that while the bulk density and the friction angle are constant, the cohesion of the surface shell is different from that of the internal core. First, developing an analytical model based on limit analysis, we provide the upper and lower bounds for the actual surface shedding condition. Second, we use a Soft-sphere Discrete Element Method (SSDEM) to study dynamical deformation of the test body due to a quasi-static spin-up. In this paper we show the consistency of both approaches. Additionally, the SSDEM simulations show that the initial failure always occurs locally and not globally. In addition, as the core becomes larger, the size of lofted components becomes smaller. These results imply that if there is a strong core in a progenitor body, surface shedding is the most likely failure mode

On the specific surface area of nanoporous materials

NARCIS (Netherlands)

Detsi, E.; De Jong, E.; Zinchenko, A.; Vukovic, Z.; Vukovic, I.; Punzhin, S.; Loos, K.; ten Brinke, G.; De Raedt, H. A.; Onck, P. R.; De Hosson, J. T. M.

2011-01-01

A proper quantification of the specific surface area of nanoporous materials is necessary for a better understanding of the properties that are affected by the high surface-area-to-volume ratio of nanoporous metals, nanoporous polymers and nanoporous ceramics. In this paper we derive an analytical

EFFECT OF RATIO OF SURFACE AREA ON THE CORROSION RATE

OpenAIRE

Dody Prayitno; M. Irsyad

2018-01-01

Aluminum and steel are used to be a construction for a building outdoor panel. Aluminum and steel are connected by bolt and nut. An atmosphere due to a corrosion of the aluminum. The corrosion possibly to cause the hole diameter of bolt and nut to become larger. Thus the bolt and nut can not enough strong to hold the panel. The panel may collapse. The aim of the research is first to answer a question where does the corrosion starts. The second is to know the effect of ratio surface area of st...

Surface runoff from urban areas. New aspects; Neue Aspekte in der Behandlung von Siedlungsabfluessen

Energy Technology Data Exchange (ETDEWEB)

Fuchs, Stephan [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Bereich Siedlungswasserwirtschaft und Wasserguetewirtschaft; Lambert, Benedikt [Bioplan Landeskulturgesellschaft, Sinsheim (Germany); Grotehusmann, Dieter [Ingenieurgesellschaft fuer Stadthydrologie, Hannover (Germany)

2010-12-15

The surface runoff from urban areas is one of the most important sources of pollutants emitted into surface waters. Suspended solids which act as a transport vehicle for many anthropogenic pollutants (e. g. heavy metals, PAH) are a key factor in this regard. The development of efficient measures of storm water runoff treatment thus requires a further differentiation of suspended solids in a fine (clay and silt) and coarse (sand and gravel) fraction. Both fractions show distinctly different characteristics in pollutant loading, transport and retention on urban surfaces and sewer systems. The primary aim of storm water runoff treatment is the reduction of the fine particles which are always highly loaded with anthropogenic pollutants. In contrast the coarse particles are almost unpolluted especially if they have a low organic share. The widespread sedimentation tanks with surface loadings between 10 and 2 m/h are very inefficient. A significant, save and lasting reduction of the emitted load of fine particles requires a considerable reduction of the surface loads. That can be achieved with the installation of lamellar settler or the utilization of the very large volumes of flood management tanks frequently present in urban areas. Filtration plants are highly efficient but there application in urban areas is limited due to their high space demands. (orig.)

ANALYSES OF ROCK SURFACE COLOUR CHANGES DUE TO WEATHERING

OpenAIRE

GOKAY, Mehmet Kemal

2018-01-01

Description parameters of rock masses and minerals include their colours as well. Colours appear in daylight for surfaced rock masses are changing slightly due to weathering layers which have been covering its surface gradually. Healthy human eyes can manage to differentiate visible light spectrum to identify colours of substances including rock masses. Then visible blackish colours of magnetite minerals, reddish colours of Terra- Rosa soils, greenish colours of weathered copper ore, pure whi...

ANALYSES OF ROCK SURFACE COLOUR CHANGES DUE TO WEATHERING

OpenAIRE

GÖKAY, Mehmet Kemal

2018-01-01

Description parameters of rock masses and minerals include their colours as well. Colours appear in daylight for surfaced rock masses are changing slightly due to weathering layers which have been covering its surface gradually. Healthy human eyes can manage to differentiate visible spectrum to identify the colours of substance including rock masses. Then visible blackish colours of magnetite minerals, reddish colours of Terra- Rosa soils, greenish colours of weathered copper ore, pure white ...

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

Energy Technology Data Exchange (ETDEWEB)

Tian, Huaiyu; Huang, Shanqian [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Zhou, Sen [Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing (China); Department of Pediatrics, Harvard Medical School, Boston, MA (United States); Bi, Peng [Discipline of Public Health, University of Adelaide, Adelaide (Australia); Yang, Zhicong, E-mail: yangzc@gzcdc.org.cn [Guangzhou Center for Disease Control and Prevention, Guangzhou (China); Li, Xiujun [School of Public Health, Shandong University, Jinan (China); Chen, Lifan [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Cazelles, Bernard [UMMISCO, UMI 209 IRD – UPMC, 93142 Bondy (France); Eco-Evolutionary Mathematic, IBENS UMR 8197, ENS, 75230 Paris Cedex 05 (France); Yang, Jing [State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Luo, Lei; Jing, Qinlong [Guangzhou Center for Disease Control and Prevention, Guangzhou (China); Yuan, Wenping [State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing (China); Pei, Yao; Sun, Zhe [Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing (China); Yue, Tianxiang [State Key Laboratory of Resources and Environment Information System, Chinese Academy of Sciences, Beijing (China); Kwan, Mei-Po [Department of Geography and Geographic Information Science, University of Illinois at Urbana-Champaign, Champaign, IL 61820 (United States); and others

2016-10-15

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

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

International Nuclear Information System (INIS)

Tian, Huaiyu; Huang, Shanqian; Zhou, Sen; Bi, Peng; Yang, Zhicong; Li, Xiujun; Chen, Lifan; Cazelles, Bernard; Yang, Jing; Luo, Lei; Jing, Qinlong; Yuan, Wenping; Pei, Yao; Sun, Zhe; Yue, Tianxiang; Kwan, Mei-Po

2016-01-01

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

Near-Field Spectral Effects due to Electromagnetic Surface Excitations

OpenAIRE

Shchegrov , Andrei ,; Joulain , Karl; Carminati , Rémi; Greffet , Jean-Jacques

2000-01-01

International audience; We demonstrate theoretically that the spectra of electromagnetic emission of surface systems can display remarkable differences in the near and the far zones. The spectral changes occur due to the loss of evanescent modes and are especially pronounced for systems which support surface waves. PACS numbers: 78.20. – e, 05.40. – a, 44.40. + a, 87.64.Xx Spectroscopy of electromagnetic radiation is perhaps the most powerful exploration tool employed in natural sciences: ast...

Influence of Alkali Treatment on the Surface Area of Aluminium Dross

Directory of Open Access Journals (Sweden)

N. S. Ahmad Zauzi

2016-01-01

Full Text Available Aluminium dross is an industrial waste from aluminium refining industry and classified as toxic substances. However, the disposal of dross as a waste is a burden to aluminium manufacturer industries due to its negative effects to the ecosystem, surface, and ground water. Therefore the purpose of this study is to evaluate the influence of sodium hydroxide (NaOH on the surface area and pore size of aluminium dross. There were 3 stages in the treatment activities, which were leaching, precipitation, and calcination process. The optimum result from this study was the surface area of aluminium dross increases from 10.1 m2/g up to 80.0 m2/g at 40°C, 1% NaOH, and 15-minute reaction time. Thus, aluminium dross has a potential to be converted into other useful material such as catalyst and absorbent. The benefit of this research is that the hazardous industrial waste can be turned into wealth to be used in other applications such as in catalytic activities and absorber in waste water treatment. Further investigation on the physicochemical of aluminium dross with different acid or alkali should be conducted to get deeper understanding on the aluminium dross as a catalyst-type material.

Indexing aortic valve area by body surface area increases the prevalence of severe aortic stenosis

DEFF Research Database (Denmark)

Jander, Nikolaus; Gohlke-Bärwolf, Christa; Bahlmann, Edda

2014-01-01

To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVAindex). Cut-off values for severe stenosis are......To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVAindex). Cut-off values for severe stenosis are...

OBSERVED ASTEROID SURFACE AREA IN THE THERMAL INFRARED

Energy Technology Data Exchange (ETDEWEB)

Nugent, C. R. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Mainzer, A.; Masiero, J.; Bauer, J.; Kramer, E.; Sonnett, S. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Wright, E. L. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Grav, T. [Planetary Science Institute, Tucson, AZ (United States)

2017-02-01

The rapid accumulation of thermal infrared observations and shape models of asteroids has led to increased interest in thermophysical modeling. Most of these infrared observations are unresolved. We consider what fraction of an asteroid’s surface area contributes the bulk of the emitted thermal flux for two model asteroids of different shapes over a range of thermal parameters. The resulting observed surface in the infrared is generally more fragmented than the area observed in visible wavelengths, indicating high sensitivity to shape. For objects with low values of the thermal parameter, small fractions of the surface contribute the majority of thermally emitted flux. Calculating observed areas could enable the production of spatially resolved thermal inertia maps from non-resolved observations of asteroids.

Assessment of dialyzer surface in online hemodiafiltration; objective choice of dialyzer surface area

Directory of Open Access Journals (Sweden)

Francisco Maduell

2015-05-01

Conclusion: The increase in 40% and 80% of dialyzer surface area entails an increase in convective volume of 6 and 16% respectively, showing minimal differences both in convective volume and clearance capacity when UFC was greater than 45 mL/h/mmHg. It is advisable to optimise dialyser efficiency to the smallest surface area possible, adjusting treatment prescription.

Surface States and Effective Surface Area on Photoluminescent P-Type Porous Silicon

Science.gov (United States)

Weisz, S. Z.; Porras, A. Ramirez; Resto, O.; Goldstein, Y.; Many, A.; Savir, E.

1997-01-01

The present study is motivated by the possibility of utilizing porous silicon for spectral sensors. Pulse measurements on the porous-Si/electrolyte system are employed to determine the surface effective area and the surface-state density at various stages of the anodization process used to produce the porous material. Such measurements were combined with studies of the photoluminescence spectra. These spectra were found to shift progressively to the blue as a function of anodization time. The luminescence intensity increases initially with anodization time, reaches a maximum and then decreases with further anodization. The surface state density, on the other hand, increases with anodization time from an initial value of about 2 x 10(exp 12)/sq cm surface to about 1013 sq cm for the anodized surface. This value is attained already after -2 min anodization and upon further anodization remains fairly constant. In parallel, the effective surface area increases by a factor of 10-30. This behavior is markedly different from the one observed previously for n-type porous Si.

Volume changes of Vatnajökull ice cap, Iceland, due to surface mass balance, ice flow, and subglacial melting at geothermal areas

DEFF Research Database (Denmark)

Magnússon, Eyjólfur; Björnson, Helgi; Dall, Jørgen

2005-01-01

We present observed changes in the geometry of western Vatnajökull over a period of about ten years which are caused by the surface mass balance, ice flow (both during surges and quiescent periods), and basal melting due to geothermal and volcanic activity. Comparison of two digital elevation...

STEREOLOGICAL ESTIMATION OF SURFACE AREA FROM DIGITAL IMAGES

Directory of Open Access Journals (Sweden)

Johanna Ziegel

2011-05-01

Full Text Available A sampling design of local stereology is combined with a method from digital stereology to yield a novel estimator of surface area based on counts of configurations observed in a digitization of an isotropic 2- dimensional slice with thickness s. As a tool, a result of the second author and J. Rataj on infinitesimal increase of volumes of morphological transforms is refined and used. The proposed surface area estimator is asymptotically unbiased in the case of sets contained in the ball centred at the origin with radius s and in the case of balls centred at the origin with unknown radius. For general shapes bounds for the asymptotic expected relative worst case error are given. A simulation example is discussed for surface area estimation based on 2×2×2-configurations.

Specific surface area evaluation method by using scanning electron microscopy

International Nuclear Information System (INIS)

Petrescu, Camelia; Petrescu, Cristian; Axinte, Adrian

2000-01-01

Ceramics are among the most interesting materials for a large category of applications, including both industry and health. Among the characteristic of the ceramic materials, the specific surface area is often difficult to evaluate.The paper presents a method of evaluation for the specific surface area of two ceramic powders by means of scanning electron microscopy measurements and an original method of computing the specific surface area.Cumulative curves are used to calculate the specific surface area under assumption that the values of particles diameters follow a normal logarithmic distribution. For two powder types, X7R and NPO the results are the following: - for the density ρ (g/cm 2 ), 5.5 and 6.0, respectively; - for the average diameter D bar (μm), 0.51 and 0.53, respectively; - for σ, 1.465 and 1.385, respectively; - for specific surface area (m 2 /g), 1.248 and 1.330, respectively. The obtained results are in good agreement with the values measured by conventional methods. (authors)

Detailed effects of particle size and surface area on 222Rn emanation of a phosphate rock.

Science.gov (United States)

Haquin, Gustavo; Yungrais, Zohar; Ilzycer, Danielle; Zafrir, Hovav; Weisbrod, Noam

2017-12-01

The dependency of radon emanation on soil texture was investigated using the closed chamber method. Ground phosphate rock with a large specific surface area was analyzed, and the presence of inner pores, as well as a high degree of roughness and heterogeneity in the phosphate particles, was found. The average radon emanation of the dry phosphate was 0.145 ± 0.016. The emanation coefficient was highest (0.169 ± 0.019) for the smallest particles (210 μm). The reduction rate followed an inverse power law. As expected, a linear dependence between the emanation coefficient and the specific surface area was found, being lower than predicted for the large specific surface area. This was most likely due to an increase in the embedding effect of radon atoms in adjacent grains separated by micropores. Results indicate that knowledge of grain radium distribution is crucial to making accurate emanation predictions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Clay mineralogy in different geomorphic surfaces in sugarcane areas

Science.gov (United States)

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

MCO gas composition for low reactive surface areas

International Nuclear Information System (INIS)

Packer, M.J.

1998-01-01

This calculation adjusts modeled output (HNF-SD-SNF-TI-040, Rev. 2) by considering lower reactive fuel surface areas and by increasing the input helium backfill overpressure from 0.5 to 1.5 atm (2.5 atm abs) to verify that MCO gas-phase oxygen concentrations can remain below 4 mole % over a 40 year interim period under a worst case condition of zero reactive surface area. Added backfill gas will dilute any gases generated during interim storage and is a strategy within the current design capability. The zero reactive surface area represents a hypothetical worst case example where there is no fuel scrap and/or damaged spent fuel rods in an MCO. Also included is a hypothetical case where only K East fuel exists in an MCO with an added backfill overpressure of 0.5 atm (1.5 atm abs)

Assessment of dialyzer surface in online hemodiafiltration; objective choice of dialyzer surface area

OpenAIRE

Francisco Maduell; Raquel Ojeda; Marta Arias-Guillén; Giannina Bazan; Manel Vera; Néstor Fontseré; Elisabeth Massó; Miquel Gómez; Lida Rodas; Mario Jiménez-Hernández; Gastón Piñeiro; Nayra Rico

2015-01-01

Introduction: Online haemodiafiltration (OL-HDF) is most effective technique; several randomised studies and meta-analyses have shown a reduction in mortality, with a directly related association with convective volume. At present, it is not properly established whether the increasing in dialyser surface area may suppose better outcomes in terms of convective and clearance efficacy. The purpose of the study was to assess the effect of increase in dialyser surface area on the convective volume...

Lage-area planar RF plasma productions by surface waves

International Nuclear Information System (INIS)

Nonaka, S.

1994-01-01

Large-area rf plasmas are confirmed to be produced by means of RF discharges inside a large-area dielectric tube. The plasma space is 73 cm x 176 cm and 2.5 cm. The plasma is thought to be produced by an odd plasma-surface wave (PSW ο ) in case of using large-area electrodes and by an even plasma-surface wave (PSW ο ) in case of without the electrodes. (author). 7 refs, 4 figs

Development of cortical thickness and surface area in autism spectrum disorder

Directory of Open Access Journals (Sweden)

Vincent T. Mensen

2017-01-01

Full Text Available Autism spectrum disorder (ASD is a neurodevelopmental disorder often associated with changes in cortical volume. The constituents of cortical volume – cortical thickness and surface area – have separable developmental trajectories and are related to different neurobiological processes. However, little is known about the developmental trajectories of cortical thickness and surface area in ASD. In this magnetic resonance imaging (MRI study, we used an accelerated longitudinal design to investigate the cortical development in 90 individuals with ASD and 90 typically developing controls, aged 9 to 20 years. We quantified cortical measures using the FreeSurfer software package, and then used linear mixed model analyses to estimate the developmental trajectories for each cortical measure. Our primary finding was that the development of surface area follows a linear trajectory in ASD that differs from typically developing controls. In typical development, we found a decline in cortical surface area between the ages of 9 and 20 that was absent in ASD. We found this pattern in all regions where developmental trajectories for surface area differed between groups. When we applied a more stringent correction that takes the interdependency of measures into account, this effect on cortical surface area retained significance for left banks of superior temporal sulcus, postcentral area, and right supramarginal area. These areas have previously been implicated in ASD and are involved in the interpretation and processing of audiovisual social stimuli and distinction between self and others. Although some differences in cortical volume and thickness were found, none survived the more stringent correction for multiple testing. This study underscores the importance of distinguishing between cortical surface area and thickness in investigating cortical development, and suggests the development of cortical surface area is of importance to ASD.

Rapid fabrication of large-area, corrosion-resistant superhydrophobic Mg alloy surfaces.

Science.gov (United States)

Xu, Wenji; Song, Jinlong; Sun, Jing; Lu, Yao; Yu, Ziyuan

2011-11-01

A superhydrophobic magnesium (Mg) alloy surface was successfully fabricated via a facile electrochemical machining process, and subsequently covered with a fluoroalkylsilane (FAS) film. The surface morphologies and chemical compositions were investigated using a scanning electron microscope (SEM) equipped with an energy-dispersive spectroscopy (EDS) and a Fourier-transform infrared spectrophotometer (FTIR). The results show hierarchal rough structures and an FAS film with a low surface energy on the Mg alloy surfaces, which confers good superhydrophobicity with a water contact angle of 165.2° and a water tilting angle of approximately 2°. The processing conditions, such as the processing time and removal rate per unit area at a constant removal mass per unit area, were investigated to determine their effects on the superhydrophobicity. Interestingly, when the removal mass per unit area is constant at approximately 11.10 mg/cm(2), the superhydrophobicity does not change with the removal rate per unit area. Therefore, a superhydrophobic Mg alloy surface can be rapidly fabricated based on this property. A large-area superhydrophobic Mg alloy surface was also fabricated for the first time using a small-area moving cathode. The corrosion resistance and durability of the superhydrophobic surfaces were also examined.

Microbiology of the surface water samples in the high background radiation areas of Ramsar, Iran

International Nuclear Information System (INIS)

Motamedifar, Mohammad; Zamani, Khosrow; Sedigh, Hadi; Mortazavi, Seyed Mohammad Javad; Taeb, Shahram; Haghani, M.; Mortazavi, Seyed Ali Reza; Soofi, Amir

2014-01-01

Residents of high background radiation areas of Ramsar have lived in these areas for many generations and received radiation doses much higher than the dose limit recommended by ICRP for radiation workers. The radioactivity of the high background radiation areas of Ramsar is reported to be due to 226 Ra and its decay products, which have been brought to the surface by the waters of hot springs. Over the past years the department has focused on different aspects of the health effects of the elevated levels of natural radiation in Ramsar. This study was aimed to perform a preliminary investigation on the bioeffects of exposure to elevated levels of natural radiation on the microbiology of surface water samples. Water samples were collected from surface water streams in Talesh Mahalleh district, Ramsar as well as a nearby area with normal levels of background radiation. Only two strains of bacteria, that is, Providencia stuartii and Shimwellia blattae, could be isolated from the water samples collected from high background radiation areas, while seven strains (Escherichia coli, Enterobacter asburiae, Klebsiella pneumoniae, Shigella dysenteriae, Buttiauxella agerstis, Tatumella punctuata and Raoultella ornithinolytica) were isolated from the water samples collected from normal background radiation areas. All the bacteria isolated from water samples of high and normal background radiation areas were sensitive to ultraviolet radiation, heat, betadine, alcohol, and deconex. Although other investigators have reported that bacteria isolated from hot springs show radioresistance, the results reported here do not reveal any adaptive response. (author)

A synthesis method for cobalt doped carbon aerogels with high surface area and their hydrogen storage properties

Energy Technology Data Exchange (ETDEWEB)

Tian, H.Y.; Buckley, C.E. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth 6845, WA (Australia); CSIRO National Hydrogen Materials Alliance, CSIRO Energy Centre, 10 Murray Dwyer Circuit, Steel River Estate, Mayfield West, NSW 2304 (Australia); Sheppard, D.A.; Paskevicius, M. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth 6845, WA (Australia); Hanna, N. [CSIRO Process Science and Engineering, Waterford, WA (Australia)

2010-12-15

Carbon aerogels doped with nanoscaled Co particles were prepared by first coating activated carbon aerogels using a wet-thin layer coating process. The resulting metal-doped carbon aerogels had a higher surface area ({proportional_to}1667 m{sup 2} g{sup -1}) and larger micropore volume ({proportional_to}0.6 cm{sup 3} g{sup -1}) than metal-doped carbon aerogels synthesised using other methods suggesting their usefulness in catalytic applications. The hydrogen adsorption behaviour of cobalt doped carbon aerogel was evaluated, displaying a high {proportional_to}4.38 wt.% H{sub 2} uptake under 4.6 MPa at -196 C. The hydrogen uptake capacity with respect to unit surface area was greater than for pure carbon aerogel and resulted in {proportional_to}1.3 H{sub 2} (wt. %) per 500 m{sup 2} g{sup -1}. However, the total hydrogen uptake was slightly reduced as compared to pure carbon aerogel due to a small reduction in surface area associated with cobalt doping. The improved adsorption per unit surface area suggests that there is a stronger interaction between the hydrogen molecules and the cobalt doped carbon aerogel than for pure carbon aerogel. (author)

Particle surface area and bacterial activity in recirculating aquaculture systems

DEFF Research Database (Denmark)

Pedersen, Per Bovbjerg; von Ahnen, Mathis; Fernandes, Paulo

2017-01-01

Suspended particles in recirculating aquaculture systems (RAS) provide surface area that can be colonized by bacteria. More particles accumulate as the intensity of recirculation increases thus potentially increasing the bacterial carrying capacity of the systems. Applying a recent, rapid, culture...... but may provide significant surface area. Hence, the study substantiates that particles in RAS provide surface area supporting bacterial activity, and that particles play a key role in controlling the bacterial carrying capacity at least in less intensive RAS. Applying fast, culture-independent techniques......-independent fluorometric detection method (Bactiquant®) for measuring bacterial activity, the current study explored the relationship between total particle surface area (TSA, derived from the size distribution of particles >5 μm) and bacterial activity in freshwater RAS operated at increasing intensity of recirculation...

Monitoring System for ALICE Surface Areas

CERN Document Server

Demirbasci, Oguz

2016-01-01

I have been at CERN for 12 weeks within the scope of Summer Student Programme working on a monitoring system project for surface areas of the ALICE experiment during this period of time. The development and implementation of a monitoring system for environmental parameters in the accessible areas where a cheap hardware setup can be deployed were aim of this project. This report explains how it was developed by using Arduino, Raspberry PI, WinCC OA and DIM protocol.

Determination of the surface area and sizes of supported copper nanoparticles through organothiol adsorption—ñhemisorption

Energy Technology Data Exchange (ETDEWEB)

Ndolomingo, Matumuene Joe; Meijboom, Reinout, E-mail: rmeijboom@uj.ac.za

2016-12-30

Highlights: • Cu on γ-Al{sub 2}O{sub 3} catalysts were prepared and characterized. • The ligand sorption-based technique was used for the determination of specific surface area and particle sizes. • The ligand packing density on Cu nanoparticles was quantified. • A fair agreement was found between the Cu particle sizes obtained from ligand adsorption and TEM methods. • The oxidation of morin by hydrogen peroxide was used to evaluate the catalytic activities of the Cu supported catalysts. - Abstract: The mechanisms involving the nanoparticle surfaces in catalytic reactions are more difficult to elucidate due to the nanoparticle surface unevenness, size distributions, and morphological irregularity. True surface area and particle sizes determination are key aspects of the activity of metal nanoparticle catalysts. Here we report on the organothiol adsorption-based technique for the determination of specific surface area of Cu nanoparticles, and their resultant sizes on γ-Al{sub 2}O{sub 3} supports. Quantification of ligand packing density on copper nanoparticles is also reported. The concentration of the probe ligand, 2-mercaptobenzimidazole (2-MBI) before and after immersion of supported copper catalysts was determined by ultraviolet-visible spectrometry (UV–vis). The amount of ligand adsorbed was found to be proportional to the copper nanoparticles surface area. Atomic absorption spectrometry (AAS), N{sub 2}-physisorption (BET), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) were used for the characterization of the catalysts. A fair agreement was found between particle sizes obtained from ligand adsorption and TEM methods. The catalytic activity of the copper nanoparticles related to their inherent surface area was evaluated using the model reaction of the oxidation of morin by hydrogen peroxide.

Probing hot-electron effects in wide area plasmonic surfaces using X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ayas, Sencer; Cupallari, Andi; Dana, Aykutlu, E-mail: aykutlu@unam.bilkent.edu.tr [UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey)

2014-12-01

Plasmon enhanced hot carrier formation in metallic nanostructures increasingly attracts attention due to potential applications in photodetection, photocatalysis, and solar energy conversion. Here, hot-electron effects in nanoscale metal-insulator-metal (MIM) structures are investigated using a non-contact X-ray photoelectron spectroscopy based technique using continuous wave X-ray and laser excitations. The effects are observed through shifts of the binding energy of the top metal layer upon excitation with lasers of 445, 532, and 650 nm wavelength. The shifts are polarization dependent for plasmonic MIM grating structures fabricated by electron beam lithography. Wide area plasmonic MIM surfaces fabricated using a lithography free route by the dewetting of evaporated Ag on HfO{sub 2} exhibit polarization independent optical absorption and surface photovoltage. Using a simple model and making several assumptions about the magnitude of the photoemission current, the responsivity and external quantum efficiency of wide area plasmonic MIM surfaces are estimated as 500 nA/W and 11 × 10{sup −6} for 445 nm illumination.

Nitrate and nitrite contamination of sub-surface water in some areas of North West Frontier Province (N.W.F.P.) Pakistan

International Nuclear Information System (INIS)

Khan, M.; Khawaja, M.A.; Imdadullah

1998-01-01

Over the past few years, nitrate and nitrite contamination of sub-surface water samples from Peshawar, Charsada, Mardan and Nowshera districts of NWFP has been studied. In all the areas under study, nitrate concentration of sub-surface water was found to be below WHO approved limit of 45 mg/l. Whereas city area after 1987 showed a decreasing level of nitrate contamination of sub-surface water, it appeared to be on the increase in water samples from the outskirts of Peshawar-Charsada road. No uniform increasing or decreasing patterns of nitrate contamination were observed for water samples from cantonment, University and Hayatabad, areas of Mardan, Charsada and Nowshera under study. The nitrate contamination of sub-surface water appeared to be due to both the agricultural activities as well as human and animal wastes. A few sub-surface water samples from Peshawar city, Mardan and Nowshera areas indicated high concentration of nitrite, which is alarming in view of the earlier reports showing absence of nitrite in water samples from these areas. However, since 1993, nitrite presence has not been detected in sub-surface water samples from all the areas under present investigation. (author)

Surface area, crystal morphology and characterization of transition alumina powders from a new gibbsite precursor

Directory of Open Access Journals (Sweden)

Antonio Carlos Vieira Coelho

2007-06-01

Full Text Available A new procedure was used to prepare a microcrystalline powder constituted by thin euhedral hexagonal gibbsite plates, 0.2 to 0.6 µm in diameter and 32 nm thick. The powder, fired between 200 and 1000 °C, produced chi and kappa transition aluminas. Alpha-alumina is formed from 1000 °C and recrystallized up to 1500 °C. At 1000 °C, kappa- and alpha-alumina coexisted, but kappa-alumina could only be characterized by SAED. The details of the internal organization of the transition alumina pseudomorphs were clearly observable in TEM due to the great thinness of the I-gibbsite plates. The specific surface area varied from pristine I-gibbsite (24.9 m².g-1 to chi- and kappa transition aluminas (25.4 m².g-1 at 1000 °C to alpha-alumina (4.0 m².g-1 at 1500 °C. The maximum value of specific surface area is 347 m².g-1 in chi-alumina powder at 300 °C, a difference from Bayer gibbsite, in which the chi-alumina highest surface area is 370 m².g-1 at 400 °C.

Surface Deformation Observed by InSAR due to Fluid Injection: a Test Study in the Central U.S.

Science.gov (United States)

Deng, F.; Dixon, T. H.

2017-12-01

The central and eastern U.S. has undergone a dramatic increase in seismicity over the past few years. Many of these recent earthquakes were likely induced by human activities, with underground fluid injection for oil and gas extraction being one of the main contributors. Surface deformation caused by fluid injection has been captured by GPS and InSAR observations in several areas. For example, surface uplift of up to 10 cm due to CO2 injection between 2007 and 2011 was measured by InSAR at an enhanced oil recovery site in west Texas. We are using Texas and Oklahoma as test areas to analyze the potential relationship between surface deformation, underground fluid injection and induced earthquakes. C-band SAR data from ENVISAT and Sentinel-1, and L-band SAR data from ALOS and ALOS-2 are used to form decade-long time series. Based on the surface deformation derived from the time series InSAR data, subsurface volume change and volumetric strain in an elastic half space are estimated. Seismic data provided by the USGS are used to analyze the spatial and temporal distribution pattern of earthquakes, and the potential link between surface deformation and induced earthquakes. The trigger mechanism will be combined with forward modeling to predict seismicity and assess related hazard for future study.

Potential Settlement Due to Seismic Effects in the Residential Area of Ilgin (Konya, Turkey

Directory of Open Access Journals (Sweden)

Adnan Ozdemir

2016-04-01

Full Text Available Ilgin lies on newly formed, loose, granular deposits, and there is a substantial risk for surface liquefaction and foundation settlements due to the seismic effects resulting from groundwater close to the surface. This study evaluates potential settlement due to seismic effects in the residential areas of Ilgin using the Standard Penetration Test (SPT performed on 45 geotechnical bores. In Turkey, where earthquakes occur frequently, the selection of residential areas is of great importance. In this research, the number of settlements was calculated considering an earthquake having a Local Magnitude of 6 (i.e., ML ≥ 6.0 and a ≥ 0.4 g under a 0.4 g seismic force, and a potential settlement map of the residential area was prepared. The amount of settlement exceeds 20 cm at locations near Ilgin Lake and in the northern section of Ilgin residential areas; downtown, the settlement ranges from 10-20 cm. The settlements presented here exceed the allowable threshold limits for structures constructed using adobe and brick in this district. Thus, improvements to minimize earthquake-induced damages are required for structures in Ilgin. Moreover, the selection of new residential areas, along with the proper design of the structures before construction, should be examined further to avoid ground liquefaction and structure damage due to settlement.    Resumen La localidad de Ilgin está ubicada sobre depósitos recién formados, granulares y no compactos, por lo que existe un riesgo sustancial de licuefacción de la superficie y la creación de asentamientos o deslizamientos debido a los efectos sísmicos resultantes del agua subterránea poco profunda. Este artículo evalúa el potencial de asentamiento debido a los efectos sísmicos en las áreas residenciales de Ilgin a través del Ensayo de Penetración Estándar (SPT, en inglés realizado en 45 perforaciones geotécnicas. En Turquía, donde los terremotos ocurren frecuentemente, la selección de �

Urban surface energy fluxes based on remotely-sensed data and micrometeorological measurements over the Kansai area, Japan

Science.gov (United States)

Sukeyasu, T.; Ueyama, M.; Ando, T.; Kosugi, Y.; Kominami, Y.

2017-12-01

The urban heat island is associated with land cover changes and increases in anthropogenic heat fluxes. Clear understanding of the surface energy budget at urban area is the most important for evaluating the urban heat island. In this study, we develop a model based on remotely-sensed data for the Kansai area in Japan and clarify temporal transitions and spatial distributions of the surface energy flux from 2000 to 2016. The model calculated the surface energy fluxes based on various satellite and GIS products. The model used land surface temperature, surface emissivity, air temperature, albedo, downward shortwave radiation and land cover/use type from the moderate resolution imaging spectroradiometer (MODIS) under cloud free skies from 2000 to 2016 over the Kansai area in Japan (34 to 35 ° N, 135 to 136 ° E). Net radiation was estimated by a radiation budget of upward/downward shortwave and longwave radiation. Sensible heat flux was estimated by a bulk aerodynamic method. Anthropogenic heat flux was estimated by the inventory data. Latent heat flux was examined with residues of the energy budget and parameterization of bulk transfer coefficients. We validated the model using observed fluxes from five eddy-covariance measurement sites: three urban sites and two forested sites. The estimated net radiation roughly agreed with the observations, but the sensible heat flux were underestimated. Based on the modeled spatial distributions of the fluxes, the daytime net radiation in the forested area was larger than those in the urban area, owing to higher albedo and land surface temperatures in the urban area than the forested area. The estimated anthropogenic heat flux was high in the summer and winter periods due to increases in energy-requirements.

Size and surface AREA analysis of some metallic and intermetallic powders

International Nuclear Information System (INIS)

Elmasry, M.A.A.; Elsayed, A.A.; Abadir, M.F.

1988-01-01

The powder characterization of three intermetallic compounds ( Cr B, B 4 c and S ib 4 ) and three metallic powders (Fe, Co, and Ni) has been performed. This included the determination of powder density, chemical analysis, impurity analysis, shape factor, particle size analysis and specific surface area. The particle size analysis for the six powders was carried out using three techniques, namely; the 0-23, the microtrac and the fisher sub sieve and size. It was found that the analysis of the two powders and deviates from the log-normal probability distribution and the deviation was corrected. The specific surface area of the powders was measured using the high speed surface area analysis (BET method), and it was also calculated from surface area analysis findings, the BET technique was found to give the highest specific surface area values, and was attributed to the inclusion of internal porosity in the measurement. 8 fig., 10 tab

Surface Area, and Oxidation Effects on Nitridation Kinetics of Silicon Powder Compacts

Science.gov (United States)

Bhatt, R. T.; Palczer, A. R.

1998-01-01

Commercially available silicon powders were wet-attrition-milled from 2 to 48 hr to achieve surface areas (SA's) ranging from 1.3 to 70 sq m/g. The surface area effects on the nitridation kinetics of silicon powder compacts were determined at 1250 or 1350 C for 4 hr. In addition, the influence of nitridation environment, and preoxidation on nitridation kinetics of a silicon powder of high surface area (approximately equals 63 sq m/g) was investigated. As the surface area increased, so did the percentage nitridation after 4 hr in N2 at 1250 or 1350 C. Silicon powders of high surface area (greater than 40 sq m/g) can be nitrided to greater than 70% at 1250 C in 4 hr. The nitridation kinetics of the high-surface-area powder compacts were significantly delayed by preoxidation treatment. Conversely, the nitridation environment had no significant influence on the nitridation kinetics of the same powder. Impurities present in the starting powder, and those accumulated during attrition milling, appeared to react with the silica layer on the surface of silicon particles to form a molten silicate layer, which provided a path for rapid diffusion of nitrogen and enhanced the nitridation kinetics of high surface area silicon powder.

Assessment of nanoparticle surface area by measuring unattached fraction of radon progeny

Energy Technology Data Exchange (ETDEWEB)

Ruzer, Lev S. [Ernest Orlando Lawrence Berkeley National Laboratory, Indoor Environment Department (United States)], E-mail: LSRuzer@lbl.gov

2008-05-15

A number of studies on the exposure of nanometer aerosols have indicated that health effects associated with low-solubility inhaled particles in the range of 1-100 nm may be more appropriately associated with particulate surface area than mass concentration. Such data on correlation between number, surface area and mass concentration are needed for exposure investigations, but the means for measuring aerosol surface area are not readily available. In this paper we propose a method for particle surface area assessment based on a new approach, deposition of the 'unattached fraction of radon progeny' onto nanometer aerosols.The proposed approach represents a synthesis of:(1) Derived direct analytical correlation between the 'unattached fraction' of radon progeny and surface area particle concentration in the range of 1-100 nm particle diameter;(2) Experimental data on correlation between the unattached fraction of radon progeny and particle surface area for particles with diameter in the range of 44 nm-2.1 {mu}m.

Porous silicon structures with high surface area/specific pore size

Science.gov (United States)

Northrup, M.A.; Yu, C.M.; Raley, N.F.

1999-03-16

Fabrication and use of porous silicon structures to increase surface area of heated reaction chambers, electrophoresis devices, and thermopneumatic sensor-actuators, chemical preconcentrates, and filtering or control flow devices. In particular, such high surface area or specific pore size porous silicon structures will be useful in significantly augmenting the adsorption, vaporization, desorption, condensation and flow of liquids and gases in applications that use such processes on a miniature scale. Examples that will benefit from a high surface area, porous silicon structure include sample preconcentrators that are designed to adsorb and subsequently desorb specific chemical species from a sample background; chemical reaction chambers with enhanced surface reaction rates; and sensor-actuator chamber devices with increased pressure for thermopneumatic actuation of integrated membranes. Examples that benefit from specific pore sized porous silicon are chemical/biological filters and thermally-activated flow devices with active or adjacent surfaces such as electrodes or heaters. 9 figs.

Can foot anthropometric measurements predict dynamic plantar surface contact area?

Directory of Open Access Journals (Sweden)

Collins Natalie

2009-10-01

Full Text Available Abstract 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 R2 = 0.76, p 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.

Stereological estimation of surface area from digital images

DEFF Research Database (Denmark)

Ziegel, Johanna; Kiderlen, Markus

2010-01-01

A sampling design of local stereology is combined with a method from digital stereology to yield a novel estimator of surface area based on counts of configurations observed in a digitization of an isotropic 2- dimensional slice with thickness s. As a tool, a result of the second author and J....... Rataj on infinitesimal increase of volumes of morphological transforms is refined and used. The proposed surface area estimator is asymptotically unbiased in the case of sets contained in the ball centred at the origin with radius s and in the case of balls centred at the origin with unknown radius...

On $L_p$ Affine Surface Area and Curvature Measures

OpenAIRE

Zhao, Yiming

2015-01-01

The relationship between $L_p$ affine surface area and curvature measures is investigated. As a result, a new representation of the existing notion of $L_p$ affine surface area depending only on curvature measures is derived. Direct proofs of the equivalence between this new representation and those previously known are provided. The proofs show that the new representation is, in a sense, "polar" to that of Lutwak's and "dual" to that of Sch\\"utt & Werner's.

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

DEFF Research Database (Denmark)

Charalampidis, C.; Van As, D.; Box, J. E.

2015-01-01

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...

High Surface Area Tunnels in Hexagonal WO₃.

Science.gov (United States)

Sun, Wanmei; Yeung, Michael T; Lech, Andrew T; Lin, Cheng-Wei; Lee, Chain; Li, Tianqi; Duan, Xiangfeng; Zhou, Jun; Kaner, Richard B

2015-07-08

High surface area in h-WO3 has been verified from the intracrystalline tunnels. This bottom-up approach differs from conventional templating-type methods. The 3.67 Å diameter tunnels are characterized by low-pressure CO2 adsorption isotherms with nonlocal density functional theory fitting, transmission electron microscopy, and thermal gravimetric analysis. These open and rigid tunnels absorb H(+) and Li(+), but not Na(+) in aqueous electrolytes without inducing a phase transformation, accessing both internal and external active sites. Moreover, these tunnel structures demonstrate high specific pseudocapacitance and good stability in an H2SO4 aqueous electrolyte. Thus, the high surface area created from 3.67 Å diameter tunnels in h-WO3 shows potential applications in electrochemical energy storage, selective ion transfer, and selective gas adsorption.

High-surface-area silica nanospheres (KCC-1) with a fibrous morphology

KAUST Repository

Polshettiwar, Vivek; Cha, Dong Kyu; Zhang, Xixiang; Basset, Jean-Marie

2010-01-01

Fibrous nanosilica: A new family of high-surface-area silica nanospheres (KCC-1) have been prepared (see picture). KCC-1 features excellent physical properties, including high surface area, unprecedented fibrous surface morphology, high thermal (up to 950 °C) and hydrothermal stabilities, and high mechanical stability. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-surface-area silica nanospheres (KCC-1) with a fibrous morphology

KAUST Repository

Polshettiwar, Vivek

2010-08-02

Fibrous nanosilica: A new family of high-surface-area silica nanospheres (KCC-1) have been prepared (see picture). KCC-1 features excellent physical properties, including high surface area, unprecedented fibrous surface morphology, high thermal (up to 950 °C) and hydrothermal stabilities, and high mechanical stability. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Why Do We Need the Derivative for the Surface Area?

Science.gov (United States)

Hristova, Yulia; Zeytuncu, Yunus E.

2016-01-01

Surface area and volume computations are the most common applications of integration in calculus books. When computing the surface area of a solid of revolution, students are usually told to use the frustum method instead of the disc method; however, a rigorous explanation is rarely provided. In this note, we provide one by using geometric…

Phenomenological study of aerosol dry deposition in urban area: surface properties, turbulence and local meteorology influences

International Nuclear Information System (INIS)

Roupsard, P.

2013-01-01

Aerosol dry deposition is not much known for urban areas due to the lack of data. Knowledge on this phenomenon is necessary to understand pollutant fluxes in cities and to estimate inhabitant exposition to ionizing radiation of radioactive aerosols. A data providing could enable to enhance dry deposition models for these areas. An original experimental approach is performed to study submicron aerosol dry deposition on urban surfaces. Wind tunnel coupled to in situ experiments give results to study different physical phenomenon governing dry deposition. Dry deposition velocities are measured using aerosol tracers. These data are associated to turbulent and meteorological measured conditions. This database permits to classify the principal physical phenomenon for each experiment type. Finally, different phenomenon must be considered for chronic and acute exposition of urban surfaces to atmospheric particles. (author)

AFM-based tribological study of nanopatterned surfaces: the influence of contact area instabilities.

Science.gov (United States)

Rota, A; Serpini, E; Gazzadi, G C; Valeri, S

2016-04-06

Although the importance of morphology on the tribological properties of surfaces has long been proved, an exhaustive understanding of nanopatterning effects is still lacking due to the difficulty in both fabricating 'really nano-' structures and detecting their tribological properties. In the present work we show how the probe-surface contact area can be a critical parameter due to its remarkable local variability, making a correct interpretation of the data very difficult in the case of extremely small nanofeatures. Regular arrays of parallel 1D straight nanoprotrusions were fabricated by means of a low-dose focused ion beam, taking advantage of the amorphization-related swelling effect. The tribological properties of the patterns were detected in the presence of air and in vacuum (dry ambient) by atomic force microscopy. We have introduced a novel procedure and data analysis to reduce the uncertainties related to contact instabilities. The real time estimation of the radius of curvature of the contacting asperity enables us to study the dependence of the tribological properties of the patterns from their geometrical characteristics. The effect of the patterns on both adhesion and the coefficient of friction strongly depends on the contact area, which is linked to the local radius of curvature of the probe. However, a detectable hydrophobic character induced on the hydrophilic native SiO2 has been observed as well. The results suggest a scenario for capillary formation on the patterns.

AFM-based tribological study of nanopatterned surfaces: the influence of contact area instabilities

International Nuclear Information System (INIS)

Rota, A; Serpini, E; Gazzadi, G C; Valeri, S

2016-01-01

Although the importance of morphology on the tribological properties of surfaces has long been proved, an exhaustive understanding of nanopatterning effects is still lacking due to the difficulty in both fabricating ‘really nano-’ structures and detecting their tribological properties. In the present work we show how the probe–surface contact area can be a critical parameter due to its remarkable local variability, making a correct interpretation of the data very difficult in the case of extremely small nanofeatures. Regular arrays of parallel 1D straight nanoprotrusions were fabricated by means of a low-dose focused ion beam, taking advantage of the amorphization-related swelling effect. The tribological properties of the patterns were detected in the presence of air and in vacuum (dry ambient) by atomic force microscopy. We have introduced a novel procedure and data analysis to reduce the uncertainties related to contact instabilities. The real time estimation of the radius of curvature of the contacting asperity enables us to study the dependence of the tribological properties of the patterns from their geometrical characteristics. The effect of the patterns on both adhesion and the coefficient of friction strongly depends on the contact area, which is linked to the local radius of curvature of the probe. However, a detectable hydrophobic character induced on the hydrophilic native SiO 2 has been observed as well. The results suggest a scenario for capillary formation on the patterns. (paper)

Assessment of mercury erosion by surface water in Wanshan mercury mining area.

Science.gov (United States)

Dai, ZhiHui; Feng, Xinbin; Zhang, Chao; Shang, Lihai; Qiu, Guangle

2013-08-01

Soil erosion is a main cause of land degradation, and in its accelerated form is also one of the most serious ecological environmental problems. Moreover, there are few studies on migration of mercury (Hg) induced by soil erosion in seriously Hg-polluted districts. This paper selected Wanshan Hg mining area, SW China as the study area. Revised universal soil loss equation (RUSLE) and Geographic information system (GIS) methods were applied to calculate soil and Hg erosion and to classify soil erosion intensity. Our results show that the soil erosion rate can reach up to 600,884tkm(-2)yr(-1). Surfaces associated with very slight and extremely severe erosion include 76.6% of the entire land in Wanshan. Furthermore, the cumulative erosion rates in the area impacted by extremely severe erosion make up 90.5% of the total. On an annual basis, Hg surface erosion load was predicted to be 505kgyr(-1) and the corresponding mean migration flux of Hg was estimated to be 3.02kgkm(-2)yr(-1). The erosion loads of Hg resulting from farmland and meadow soil were 175 and 319kgyr(-1) respectively, which were enhanced compared to other landscape types due to the fact that they are generally located in the steep zones associated with significant reclamation. Contributing to establish a mass balance of Hg in Wanshan Hg mining area, this study supplies a dependable scientific basis for controlling soil and water erosion in the local ecosystems. Land use change is the most effective way for reducing Hg erosion load in Wanshan mining area. Copyright © 2013 Elsevier Inc. All rights reserved.

Assessment of damage to the desert surfaces of Kuwait due to the Gulf War

International Nuclear Information System (INIS)

El-Baz, F.; Al-Ajmi, D.

1993-01-01

This is a preliminary report on a joint research project by Boston University and the Kuwait Institute for Scientific Research that commenced in April 1992. The project aim is to establish the extent and nature of environmental damage to the desert surface and coastal zone of Kuwait due to the Gulf War and its aftermath. Change detection image enhancement techniques were employed to enhance environmental change by comparison of Landsat Thematic Mapper images obtained before the wars and after the cessation of the oil and well fires. Higher resolution SPOT images were also utilized to evaluate the nature of the environmental damage to specific areas. The most prominent changes were due to: (1) the deposition of oil and course-grained soot on the desert surface as a result of ''oil rain'' from the plume that emanated from the oil well fires; (2) the formation of hundreds of oil lakes, from oil seepage at the damaged oil well heads; (3) the mobilization of sand and dust and (4) the pollution of segments of the coastal zone by the deposition of oil from several oil spills. Interpretation of satellite image data are checked in the field to confirm the observations, and to assess the nature of the damage. Final results will be utilized in establishing the needs for remedial action to counteract the harmful effects of the various types of damage to the environment of Kuwait

Decadal changes of surface elevation over permafrost area estimated using reflected GPS signals

Science.gov (United States)

Liu, Lin; Larson, Kristine M.

2018-02-01

Conventional benchmark-based survey and Global Positioning System (GPS) have been used to measure surface elevation changes over permafrost areas, usually once or a few times a year. Here we use reflected GPS signals to measure temporal changes of ground surface elevation due to dynamics of the active layer and near-surface permafrost. Applying the GPS interferometric reflectometry technique to the multipath signal-to-noise ratio data collected by a continuously operating GPS receiver mounted deep in permafrost in Barrow, Alaska, we can retrieve the vertical distance between the antenna and reflecting surface. Using this unique kind of observables, we obtain daily changes of surface elevation during July and August from 2004 to 2015. Our results show distinct temporal variations at three timescales: regular thaw settlement within each summer, strong interannual variability that is characterized by a sub-decadal subsidence trend followed by a brief uplift trend, and a secular subsidence trend of 0.26 ± 0.02 cm year-1 during 2004 and 2015. This method provides a new way to fully utilize data from continuously operating GPS sites in cold regions for studying dynamics of the frozen ground consistently and sustainably over a long time.

Raising surface water levels in peat areas with dairy farming upscaling hydrological, agronomical and economic effects from farm-scale to local scale.

NARCIS (Netherlands)

Vos, de J.A.; Bakel, van P.J.T.; Hoving, I.E.; Smidt, R.A.

2010-01-01

Raising surface water levels in peat areas is a measure to reduce soil subsidence, to prevent decay of wooden foundations and to stimulate wet nature restoration and reduce greenhouse gas emissions. However, in these areas dairy farms are present and farming at wetter soils is difficult due to lower

High surface area carbon and process for its production

Energy Technology Data Exchange (ETDEWEB)

Romanos, Jimmy; Burress, Jacob; Pfeifer, Peter; Rash, Tyler; Shah, Parag; Suppes, Galen

2016-12-13

Activated carbon materials and methods of producing and using activated carbon materials are provided. In particular, biomass-derived activated carbon materials and processes of producing the activated carbon materials with prespecified surface areas and pore size distributions are provided. Activated carbon materials with preselected high specific surface areas, porosities, sub-nm (<1 nm) pore volumes, and supra-nm (1-5 nm) pore volumes may be achieved by controlling the degree of carbon consumption and metallic potassium intercalation into the carbon lattice during the activation process.

Surface water and groundwater interaction in Marala - Khanki area, Punjab

International Nuclear Information System (INIS)

Akram, W.; Ahmad, M.; Latif, Z.; Tariq, J.A.; Malik, M.R.

2011-07-01

Isotope hydrological investigations were carried out in two selected areas of Indus Basin viz. Haripur Area and Chashma- Taunsa Area for elucidating various aspects of surface water and groundwater interaction. Groundwater samples were collected on seasonal basis (low and high river discharge periods) while surface water samples were collected more frequently (weekly or monthly basis). Isotopic data suggested that there is no contribution of surface water to groundwater recharge in Haripur Area and rain is the prevailing source of groundwater recharge. The data further revealed that isotopic values of the Haripur pocket of Tarbela Lake are higher than those of Main Lake / Indus River meaning that there is a significant contribution of base flow in this pocket. Indus River appeared to be the dominant source of groundwater recharge at most of the locations in Chashma- Taunsa Area. Isotopic data of Indus River showed an increase at Taunsa as compared to Chashma in low flow period indicating the high contribution of base flow at this point in time. Stable isotopes were successfully used to quantify the base flow contribution. (author)

Cortical Thickness, Surface Area and Subcortical Volume Differentially Contribute to Cognitive Heterogeneity in Parkinson's Disease.

Science.gov (United States)

Gerrits, Niels J H M; van Loenhoud, Anita C; van den Berg, Stan F; Berendse, Henk W; Foncke, Elisabeth M J; Klein, Martin; Stoffers, Diederick; van der Werf, Ysbrand D; van den Heuvel, Odile A

2016-01-01

Parkinson's disease (PD) is often associated with cognitive deficits, although their severity varies considerably between patients. Recently, we used voxel-based morphometry (VBM) to show that individual differences in gray matter (GM) volume relate to cognitive heterogeneity in PD. VBM does, however, not differentiate between cortical thickness (CTh) and surface area (SA), which might be independently affected in PD. We therefore re-analyzed our cohort using the surface-based method FreeSurfer, and investigated (i) CTh, SA, and (sub)cortical GM volume differences between 93 PD patients and 45 matched controls, and (ii) the relation between these structural measures and cognitive performance on six neuropsychological tasks within the PD group. We found cortical thinning in PD patients in the left pericalcarine gyrus, extending to cuneus, precuneus and lingual areas and left inferior parietal cortex, bilateral rostral middle frontal cortex, and right cuneus, and increased cortical surface area in the left pars triangularis. Within the PD group, we found negative correlations between (i) CTh of occipital areas and performance on a verbal memory task, (ii) SA and volume of the frontal cortex and visuospatial memory performance, and, (iii) volume of the right thalamus and scores on two verbal fluency tasks. Our primary findings illustrate that i) CTh and SA are differentially affected in PD, and ii) VBM and FreeSurfer yield non-overlapping results in an identical dataset. We argue that this discrepancy is due to technical differences and the subtlety of the PD-related structural changes.

Anomalous surface behavior of hydrated guanidinium ions due to ion pairing

Science.gov (United States)

Ekholm, Victor; Vazdar, Mario; Mason, Philip E.; Bialik, Erik; Walz, Marie-Madeleine; Öhrwall, Gunnar; Werner, Josephina; Rubensson, Jan-Erik; Jungwirth, Pavel; Björneholm, Olle

2018-04-01

Surface affinity of aqueous guanidinium chloride (GdmCl) is compared to that of aqueous tetrapropylammonium chloride (TPACl) upon addition of sodium chloride (NaCl) or disodium sulfate (Na2SO4). The experimental results have been acquired using the surface sensitive technique X-ray photoelectron spectroscopy on a liquid jet. Molecular dynamics simulations have been used to produce radial distribution functions and surface density plots. The surface affinities of both TPA+ and Gdm+ increase upon adding NaCl to the solution. With the addition of Na2SO4, the surface affinity of TPA+ increases, while that of Gdm+ decreases. From the results of MD simulations it is seen that Gdm+ and SO4 2 - ions form pairs. This finding can be used to explain the decreased surface affinity of Gdm+ when co-dissolved with SO4 2 - ions. Since SO4 2 - ions avoid the surface due to the double charge and strong water interaction, the Gdm+-SO4 2 - ion pair resides deeper in the solutions' bulk than the Gdm+ ions. Since TPA+ does not form ion pairs with SO4 2 -, the TPA+ ions are instead enriched at the surface.

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

Science.gov (United States)

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

2016-03-01

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

Robot Towed Shortwave Infrared Camera for Specific Surface Area Retrieval of Surface Snow

Science.gov (United States)

Elliott, J.; Lines, A.; Ray, L.; Albert, M. R.

2017-12-01

Optical grain size and specific surface area are key parameters for measuring the atmospheric interactions of snow, as well as tracking metamorphosis and allowing for the ground truthing of remote sensing data. We describe a device using a shortwave infrared camera with changeable optical bandpass filters (centered at 1300 nm and 1550 nm) that can be used to quickly measure the average SSA over an area of 0.25 m^2. The device and method are compared with calculations made from measurements taken with a field spectral radiometer. The instrument is designed to be towed by a small autonomous ground vehicle, and therefore rides above the snow surface on ultra high molecular weight polyethylene (UHMW) skis.

Nondestructive, stereological estimation of canopy surface area

DEFF Research Database (Denmark)

Wulfsohn, Dvora-Laio; Sciortino, Marco; Aaslyng, Jesper M.

2010-01-01

We describe a stereological procedure to estimate the total leaf surface area of a plant canopy in vivo, and address the problem of how to predict the variance of the corresponding estimator. The procedure involves three nested systematic uniform random sampling stages: (i) selection of plants from...... a canopy using the smooth fractionator, (ii) sampling of leaves from the selected plants using the fractionator, and (iii) area estimation of the sampled leaves using point counting. We apply this procedure to estimate the total area of a chrysanthemum (Chrysanthemum morifolium L.) canopy and evaluate both...... the time required and the precision of the estimator. Furthermore, we compare the precision of point counting for three different grid intensities with that of several standard leaf area measurement techniques. Results showed that the precision of the plant leaf area estimator based on point counting...

Lake Chad Total Surface Water Area as Derived from Land Surface Temperature and Radar Remote Sensing Data

Directory of Open Access Journals (Sweden)

Frederick Policelli

2018-02-01

Full Text Available Lake Chad, located in the middle of the African Sahel belt, underwent dramatic decreases in the 1970s and 1980s leaving less than ten percent of its 1960s surface water extent as open water. In this paper, we present an extended record (dry seasons 1988–2016 of the total surface water area of the lake (including both open water and flooded vegetation derived using Land Surface Temperature (LST data (dry seasons 2000–2016 from the NASA Terra MODIS sensor and EUMETSAT Meteosat-based LST measurements (dry seasons 1988–2001 from an earlier study. We also examine the total surface water area for Lake Chad using radar data (dry seasons 2015–2016 from the ESA Sentinel-1a mission. For the limited number of radar data sets available to us (18 data sets, we find on average a close match between the estimates from these data and the corresponding estimates from LST, though we find spatial differences in the estimates using the two types of data. We use these spatial differences to adjust the record (dry seasons 2000–2016 from MODIS LST. Then we use the adjusted record to remove the bias of the existing LST record (dry seasons 1988–2001 derived from Meteosat measurements and combine the two records. From this composite, extended record, we plot the total surface water area of the lake for the dry seasons of 1988–1989 through 2016–2017. We find for the dry seasons of 1988–1989 to 2016–2017 that the maximum total surface water area of the lake was approximately 16,800 sq. km (February and May, 2000, the minimum total surface water area of the lake was approximately 6400 sq. km (November, 1990, and the average was approximately 12,700 sq. km. Further, we find the total surface water area of the lake to be highly variable during this period, with an average rate of increase of approximately 143 km2 per year.

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

Directory of Open Access Journals (Sweden)

Cristina R. Perez

2014-05-01

Full Text Available 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.

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

Science.gov (United States)

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.

The Investigation of a Sinkhole Area in Germany by Near-Surface Active Seismic Tomography

Science.gov (United States)

Tschache, S.; Becker, D.; Wadas, S. H.; Polom, U.; Krawczyk, C. M.

2017-12-01

In November 2010, a 30 m wide and 17 m deep sinkhole occurred in a residential area of Schmalkalden, Germany, which fortunately did not harm humans, but led to damage of buildings and property. Subsequent geoscientific investigations showed that the collapse was naturally caused by the subrosion of sulfates in a depth of about 80 m. In 2012, an early warning system was established including 3C borehole geophones deployed in 50 m depth around the backfilled sinkhole. During the acquisition of two shallow 2D shear wave seismic profiles, the signals generated by a micro-vibrator at the surface were additionally recorded by the four borehole geophones of the early warning system and a VSP probe in a fifth borehole. The travel time analysis of the direct arrivals enhanced the understanding of wave propagation in the area. Seismic velocity anomalies were detected and related to structural seismic images of the 2D profiles. Due to the promising first results, the experiment was further extended by distributing vibration points throughout the whole area around the sinkhole. This time, micro-vibrators for P- and S-wave generation were used. The signals were recorded by the borehole geophones and temporary installed seismometers at surface positions close to the boreholes. The travel times and signal attenuations are evaluated to detect potential instable zones. Furthermore, array analyses are performed. The first results reveal features in the active tomography datasets consistent with structures observed in the 2D seismic images. The advantages of the presented method are the low effort and good repeatability due to the permanently installed borehole geophones. It has the potential to determine P-wave and S-wave velocities in 3D. It supports the interpretation of established investigation methods as 2D surface seismics and VSP. In our further research we propose to evaluate the suitability of the method for the time lapse monitoring of changes in the seismic wave

Osmosis and Surface Area to Volume Ratio.

Science.gov (United States)

Barrett, D. R. B.

1984-01-01

Describes an experiment designed to help students understand the concepts of osmosis and surface area to volume ratio (SA:VOL). The task for students is to compare water uptake in different sizes of potato cubes and relate differences to their SA:VOL ratios. (JN)

NEW CONCEPTS AND TEST METHODS OF CURVE PROFILE AREA DENSITY IN SURFACE: ESTIMATION OF AREAL DENSITY ON CURVED SPATIAL SURFACE

OpenAIRE

Hong Shen

2011-01-01

The concepts of curve profile, curve intercept, curve intercept density, curve profile area density, intersection density in containing intersection (or intersection density relied on intersection reference), curve profile intersection density in surface (or curve intercept intersection density relied on intersection of containing curve), and curve profile area density in surface (AS) were defined. AS expressed the amount of curve profile area of Y phase in the unit containing surface area, S...

Amylolytic hydrolysis of native starch granules affected by granule surface area.

Science.gov (United States)

Kim, J C; Kong, B W; Kim, M J; Lee, S H

2008-11-01

Initial stage of hydrolysis of native starch granules with various amylolytic enzymes, alpha-amylase from Bacillus subtilis, glucoamylase I (GA-I) and II (GA-II) from Aspergillus niger, and beta-amylase from sweet potato showed that the reaction was apparently affected by a specific surface area of the starch granules. The ratios of the reciprocal of initial velocity of each amylolytic hydrolysis for native potato and maize starch to that for rice with the amylolytic enzymes were nearly equivalent to the ratio of surface area per mass of the 2 starch granules to that of rice, that is, 6.94 and 2.25, respectively. Thus, the reciprocal of initial velocity of each enzymatic hydrolysis as expressed in a Lineweaver-Burk plot was a linear function of the reciprocal of surface area for each starch granule. As a result, it is concluded that amylolytic hydrolysis of native starch granules is governed by the specific surface area, not by the mass concentration, of each granule.

High surface area fibrous silica nanoparticles

KAUST Repository

Polshettiwar, Vivek; Basset, Jean-Marie

2014-01-01

Disclosed are high surface area nanoparticles that have a fibrous morphology. The nanoparticles have a plurality of fibers, wherein each fiber is in contact with one other fiber and each fiber has a length of between about 1 nm and about 5000 nm. Also disclosed are applications of the nanoparticles of the present invention, and methods of fabrication of the nanoparticles of the present invention.

High surface area fibrous silica nanoparticles

KAUST Repository

Polshettiwar, Vivek

2014-11-11

Disclosed are high surface area nanoparticles that have a fibrous morphology. The nanoparticles have a plurality of fibers, wherein each fiber is in contact with one other fiber and each fiber has a length of between about 1 nm and about 5000 nm. Also disclosed are applications of the nanoparticles of the present invention, and methods of fabrication of the nanoparticles of the present invention.

Root surface area measurement of permanent dentition in Indian population – CBCT analysis

Directory of Open Access Journals (Sweden)

Kanika Lakhani

2017-01-01

Full Text Available The area of the root surface of human teeth has been investigated extensively in the dental literature. All previous attempts mainly rely on the use of physical methods to calculate surface area on extracted teeth or use virtual 3D Models for the same. The aim is to develop an algorithm using MATLAB software that estimates the dimensions of 3-D image produced with the help of CBCT so that the same can be utilized to calculate the root surface area of teeth among Indian population. Present research utilizes CBCT images of samples of extracted teeth mounted on a customized jpg. A descriptive chart for statistical analysis has been prepared to obtain average root surface area of each tooth type. The currently developed algorithm has been successfully applied to the CBCT images of complete sample of teeth to obtain their root surface area. The algorithm developed to calculate root surface area of the teeth holds wide spread application in the field of dentistry pursuing its high expediency in even various specializations of dentistry including orthodontics, prosthodontics, periodontology and implantalogy. It is concluded that it has now become a reality to accurately determine the surface area of the root of human teeth without extracting them using the CBCT radiographs of the patients.

Surface area of antimony oxide by isotope exchange and other methods

Energy Technology Data Exchange (ETDEWEB)

Rao, Y.K.; Acharya, B.V.; Rangamannar, B.

1985-06-17

Specific surface areas of antimony oxide samples, one commercial, the other prepared from antimony trichloride were measured by heterogeneous isotope exchange, gas adsorption, air permeability and microscopic methods. Specific surface areas obtained by these four methods for the two samples were compared and the observed differences are explained.

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

Science.gov (United States)

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.

Evaluation of The Surface Ozone Concentrations In Greater Cairo Area With Emphasis On Helwan, Egypt

International Nuclear Information System (INIS)

Ramadan, A.; Kandil, A.T.; Abd Elmaged, S.M.; Mubarak, I.

2011-01-01

Various biogenic and anthropogenic sources emit huge quantities of surface ozone. The main purpose of this study is to evaluate the surface ozone levels present at Helwan area in order to improve the knowledge and understanding troposphere processes. Surface Ozone has been measured at 2 sites at Helwan; these sites cover the most populated area in Helwan. Ozone concentration is continuously monitored by UV absorption photometry using the equipment O 3 41 M UV Photometric Ozone Analyzer. The daily maximum values of the ozone concentration in the greater Cairo area have approached but did not exceeded the critical levels during the year 2008. Higher ozone concentrations at Helwan are mainly due to the transport of ozone from regions further to the north of greater Cairo and to a lesser extent of ozone locally generated by photochemical smog process. The summer season has the largest diurnal variation, with the tendency of the daily ozone maxima occur in the late afternoon. The night time concentration of ozone was significantly higher at Helwan because there are no fast acting sinks, destroying ozone since the average night time concentration of ozone is maintained at 40 ppb at the site. No correlation between the diurnal total suspended particulate (TSP) matter and the diurnal cumulative ozone concentration was observed during the Khamasin period

Surface-Casting Synthesis of Mesoporous Zirconia with a CMK-5-Like Structure and High Surface Area.

Science.gov (United States)

Gu, Dong; Schmidt, Wolfgang; Pichler, Christian M; Bongard, Hans-Josef; Spliethoff, Bernd; Asahina, Shunsuke; Cao, Zhengwen; Terasaki, Osamu; Schüth, Ferdi

2017-09-04

About 15 years ago, the Ryoo group described the synthesis of CMK-5, a material consisting of a hexagonal arrangement of carbon nanotubes. Extension of the surface casting synthesis to oxide compositions, however, was not possible so far, in spite of many attempts. Here it is demonstrated, that crystalline mesoporous hollow zirconia materials with very high surface areas up to 400 m 2  g -1 , and in selected cases in the form of CMK-5-like, are indeed accessible via such a surface casting process. The key for the successful synthesis is an increased interaction between the silica hard template surface and the zirconia precursor species by using silanol group-rich mesoporous silica as a hard template. The surface areas of the obtained zirconias exceed those of conventionally hard-templated ones by a factor of two to three. The surface casting process seems to be applicable also to other oxide materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Large area, surface discharge pumped, vacuum ultraviolet light source

Science.gov (United States)

Sze, R.C.; Quigley, G.P.

1996-12-17

Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source is disclosed. A contamination-free VUV light source having a 225 cm{sup 2} emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm{sup 2} at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing. 3 figs.

Determining eyeball surface area directly exposed to the effects of external factors.

Science.gov (United States)

Juliszewski, Tadeusz; Kadłuczka, Filip; Kiełbasa, Paweł

2016-01-01

This article discusses determining the surface area of eyeballs of men and women exposed to the direct effects of external factors in the working environment. For one eye, the mean surface is 172-182 mm(2). The determined surface area can be used in formulas for calculating the exposure of eyeballs to harmful chemical substances in workplace air.

Cortical surface area and cortical thickness in the precuneus of adult humans.

Science.gov (United States)

Bruner, E; Román, F J; de la Cuétara, J M; Martin-Loeches, M; Colom, R

2015-02-12

The precuneus has received considerable attention in the last decade, because of its cognitive functions, its role as a central node of the brain networks, and its involvement in neurodegenerative processes. Paleoneurological studies suggested that form changes in the deep parietal areas represent a major character associated with the origin of the modern human brain morphology. A recent neuroanatomical survey based on shape analysis suggests that the proportions of the precuneus are also a determinant source of overall brain geometrical differences among adult individuals, influencing the brain spatial organization. Here, we evaluate the variation of cortical thickness and cortical surface area of the precuneus in a sample of adult humans, and their relation with geometry and cognition. Precuneal thickness and surface area are not correlated. There is a marked individual variation. The right precuneus is thinner and larger than the left one, but there are relevant fluctuating asymmetries, with only a modest correlation between the hemispheres. Males have a thicker cortex but differences in cortical area are not significant between sexes. The surface area of the precuneus shows a positive allometry with the brain surface area, although the correlation is modest. The dilation/contraction of the precuneus, described as a major factor of variability within adult humans, is associated with absolute increase/decrease of its surface, but not with variation in thickness. Precuneal thickness, precuneal surface area and precuneal morphology are not correlated with psychological factors such as intelligence, working memory, attention control, and processing speed, stressing further possible roles of this area in supporting default mode functions. Beyond gross morphology, the processes underlying the large phenotypic variation of the precuneus must be further investigated through specific cellular analyses, aimed at considering differences in cellular size, density

Large-area uniform periodic microstructures on fused silica induced by surface phonon polaritons and incident laser

Science.gov (United States)

Zhang, Chuanchao; Liao, Wei; Zhang, Lijuan; Jiang, Xiaolong; Chen, Jing; Wang, Haijun; Luan, Xiaoyu; Yuan, Xiaodong

2018-06-01

A simple and convenient means to self-organize large-area uniform periodic microstructures on fused silica by using multiple raster scans of microsecond CO2 laser pulses with beam spot overlapping at normal incidence is presented, which is based on laser-induced periodic surface structures (LIPSS) attributed to the interference between surface phonon polaritons and incident CO2 laser. The evolution of fused silica surface morphologies with increasing raster scans indicates that the period of microstructures changed from 10.6 μm to 9 μm and the profiles of microstructures changed from a sinusoidal curve to a half-sinusoidal shape. Numerical simulation results suggest that the formation of the half-sinusoidal profile is due to the exponential relationship between evaporation rate and surface temperature inducing by the intensive interference between surface phonon polaritons and incident laser. The fabricated uniform periodic microstructures show excellent structural color effect in both forward-diffraction and back-diffraction.

Effect of impervious surface area and vegetation changes on mean ...

African Journals Online (AJOL)

adeniyi adeyemi

Land surface temperature (LST) is measured by the surface energy balance, .... climatic and environmental conditions (Cheng et al., 2006). ..... urban areas have generally resulted in a high reflection and emission of solar radiation and greater.

Ergodization of magnetic surfaces due to finite beta effect in a helical system

International Nuclear Information System (INIS)

Hayashi, Takaya.

1989-04-01

Breaking of magnetic surfaces due to finite beta effect in a l=2 heliotron/torsatron configuration is studied by using a newly developed three dimensional equilibrium code. Breaking can be suppressed by a larger aspect ratio configuration, shaping of magnetic surface (inward shift or prolate shape), pitch modulation of helical coils, or pressure profile control. (author)

Surface Area of Patellar Facets: Inferential Statistics in the Iraqi Population

Directory of Open Access Journals (Sweden)

Ahmed Al-Imam

2017-01-01

Full Text Available Background. The patella is the largest sesamoid bone in the body; its three-dimensional complexity necessitates biomechanical perfection. Numerous pathologies occur at the patellofemoral unit which may end in degenerative changes. This study aims to test the presence of statistical correlation between the surface areas of patellar facets and other patellar morphometric parameters. Materials and Methods. Forty dry human patellae were studied. The morphometry of each patella was measured using a digital Vernier Caliper, electronic balance, and image analyses software known as ImageJ. The patellar facetal surface area was correlated with patellar weight, height, width, and thickness. Results. Inferential statistics proved the existence of linear correlation of total facetal surface area and patellar weight, height, width, and thickness. The correlation was strongest for surface area versus patellar weight. The lateral facetal area was found persistently larger than the medial facetal area, the p value was found to be <0.001 (one-tailed t-test for right patellae, and another significant p value of < 0.001 (one-tailed t-test was found for left patellae. Conclusion. These data are vital for the restoration of the normal biomechanics of the patellofemoral unit; these are to be consulted during knee surgeries and implant designs and can be of an indispensable anthropometric, interethnic, and biometric value.

Evaluation of surface contamination due to alpha using large area contamination monitors

International Nuclear Information System (INIS)

Raghavayya, M.

1998-01-01

Radioactive contamination at work places is evaluated routinely using either the swipe sampling technique or a contamination monitor. Commercially available alpha probes used for the purpose are usually circular and have a face diameter of 50 or 100 mm. Square faced probes are also available. A thin aluminized mylar membrane of thickness 0.45 to 0.9 mg.cm -2 is used to screen the phosphor in the alpha probe to protect it from external light. The membrane cuts off more alphas from low energy emitters than from higher energy alpha emitters. Moreover the response of the detector for alphas originating at all points under the detector face is not uniform, especially when the large area alpha monitors are used. These factors can introduce errors as high as 40% into the measurements. This paper aims to quantify these errors and describe a procedure to overcome the limitations. (author)

Landuse change detection in a surface coal mine area using multi-temporal high resolution satellite images

Energy Technology Data Exchange (ETDEWEB)

Demirel, N.; Duzgun, S.; Kemal Emil, M. [Middle East Technical Univ., Ankara (Turkey). Dept. of Mining Engineering

2010-07-01

Changes in the landcover and landuse of a mine area can be caused by surface mining activities, exploitation of ore and stripping and dumping overburden. In order to identify the long-term impacts of mining on the environment and land cover, these changes must be continuously monitored. A facility to regularly observe the progress of surface mining and reclamation is important for effective enforcement of mining and environmental regulations. Remote sensing provides a powerful tool to obtain rigorous data and reduce the need for time-consuming and expensive field measurements. The purpose of this study was to conduct post classification change detection for identifying, quantifying, and analyzing the spatial response of landscape due to surface lignite coal mining activities in Goynuk, Bolu, Turkey, from 2004 to 2008. The paper presented the research algorithm which involved acquiring multi temporal high resolution satellite data; preprocessing the data; performing image classification using maximum likelihood classification algorithm and performing accuracy assessment on the classification results; performing post classification change detection algorithm; and analyzing the results. Specifically, the paper discussed the study area, data and methodology, and image preprocessing using radiometric correction. Image classification and change detection were also discussed. It was concluded that the mine and dump area decreased by 192.5 ha from 2004 to 2008 and was caused by the diminishing reserves in the area and decline in the required production. 5 refs., 2 tabs., 4 figs.

Enhancement of Friction against a Rough Surface by a Ridge-Channel Surface Microstructure.

Science.gov (United States)

Bai, Ying; Hui, Chung-Yuen; Levrard, Benjamin; Jagota, Anand

2015-07-14

We report on a study of the sliding friction of elastomeric surfaces patterned with ridges and channels (and unstructured flat controls), against both smooth and roughened spherical indenters. Against the smooth spherical indenter, all of the structured surfaces have highly reduced sliding friction due to the reduction in actual area of contact. Against roughened spherical indenters, however, the sliding force for structured samples can be up to 50% greater than that of an unstructured flat control. The mechanism of enhanced friction against a rough surface is due to a combination of increased actual area of contact, interlocking between roughness and the surface structure, and attendant dynamic instabilities that dissipate energy.

Thermal Desorption Analysis of Effective Specific Soil Surface Area

Science.gov (United States)

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.

Characteristics of surface O3 over Qinghai Lake area in Northeast Tibetan Plateau, China

International Nuclear Information System (INIS)

Shen, Zhenxing; Cao, Junji; Zhang, Leiming; Zhao, Zhuzi; Dong, Jungang; Wang, Linqing; Wang, Qiyuan; Li, Guohui; Liu, Suixin; Zhang, Qian

2014-01-01

Surface O 3 was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3200 m above sea level) in Qinghai Lake area (36°58′37″N, 99°53′56″E) in Northeast Tibetan Plateau, China. Daily average O 3 ranged from 21.8 ppbv to 65.3 ppbv with an annual average of 41.0 ppbv. Seasonal average of O 3 followed a decreasing order of summer > autumn > spring > winter. Diurnal variations of O 3 showed low concentrations during daytime and high concentrations during late night and early morning. An intensive campaign was also conducted during Aug. 13–31, 2010 to investigate correlations between meteorological or chemical conditions and O 3 . It was found that O 3 was poorly correlated with solar radiation due to the insufficient NO x in the ambient air, thus limiting O 3 formation under strong solar radiation. In contrast, high O 3 levels always coincided with strong winds, suggesting that stratospheric O 3 and long range transport might be the main sources of O 3 in this rural area. Back-trajectory analysis supported this hypothesis and further indicated the transport of air masses from northwest, northeast and southeast directions. - Highlights: • Surface O 3 was measured in Qinghai Lake area in Northeast Tibetan Plateau, China. • The O 3 chemical formation was under a strong NOx-limited in Qinghai Lake areas. • Stratospheric O 3 and transport might be the main sources of O 3 in this area

Body surface area determined by whole-body CT scanning: need for new formulae?

DEFF Research Database (Denmark)

Villa, Chiara; Primeau, Charlotte; Hesse, Ulrik

2017-01-01

Calculation of the estimated body surface area (BSA) by body height and weight has been a challenge in the past centuries due to lack of a well-documented gold standard. More recently, available techniques such as 3D laser surface scanning and CT scanning may be expected to quantify the BSA...... Mimics software, and BSA values were automatically extracted from the program. They were compared with nine predictive equations from the literature. Remarkably, close correlations (r > 0·90) were found between BSA values from CT scans and those from the predictive formulae. A mean BSA of the 54 cadavers...... equations, with the CT scan determination as gold standard. It is concluded that DuBois and DuBois' equation can be safely used in normal-weight male subjects with high accuracy, but it seems likely that BSA is underestimated in underweight subjects and overestimated in overweight individuals. Creation...

Preparation, Surface and Pore Structure of High Surface Area Activated Carbon Fibers from Bamboo by Steam Activation

Directory of Open Access Journals (Sweden)

Xiaojun Ma

2014-06-01

Full Text Available High surface area activated carbon fibers (ACF have been prepared from bamboo by steam activation after liquefaction and curing. The influences of activation temperature on the microstructure, surface area and porosity were investigated. The results showed that ACF from bamboo at 850 °C have the maximum iodine and methylene blue adsorption values. Aside from the graphitic carbon, phenolic and carbonyl groups were the predominant functions on the surface of activated carbon fiber from bamboo. The prepared ACF from bamboo were found to be mainly type I of isotherm, but the mesoporosity presented an increasing trend after 700 °C. The surface area and micropore volume of samples, which were determined by application of the Brunauer-Emmett-Teller (BET and t-plot methods, were as high as 2024 m2/g and 0.569 cm3/g, respectively. It was also found that the higher activation temperature produced the more ordered microcrystalline structure of ACF from bamboo.

Frictional behavior and BET surface-area changes of SAFOD gouge at intermediate to seismic slip rates

Science.gov (United States)

Sawai, Michiyo; Shimamoto, Toshihiko; Mitchell, Thomas; Kitajima, Hiroko; Hirose, Takehiro

2013-04-01

specific surface area (2.6-3.4 m2/g) increases to 14-24 m2/g for dry gouge deformed at intermediate slip rates and to 45-60 m2/g for wet gouge deformed at subseismic to seismic slip rates. The results suggest that approximately 2 % and less than 1 % of the frictional work is absorbed in grain crushing for dry and wet gouges, respectively, if the fracture surface energy of muscovite (0.38 J/m2) is used as the surface energy of phyllosilicate-rich SAFOD gouge. Thus grain crushing cannot be an important energy sink during seismic fault motion. The surface area tends to be lower for gouge deformed at high slip rates for both dry and wet gouges. This results and SEM observations of gouge strongly suggests that welding of grains takes place at high slip rate due to frictional heating and counteracts the surface-area increase due to grain crushing. Thus intrafault processes are more complex than in a simple scenario of "grain crushing and surface-area increase" assumed in recent studies. Surface area is greater for wet gouge than for dry gouge suggesting that pore water separating gouge particles suppresses grain welding.

Whole object surface area and volume of partial-view 3D models

International Nuclear Information System (INIS)

Mulukutla, Gopal K; Proussevitch, Alexander A; Genareau, Kimberly D; Durant, Adam J

2017-01-01

Micro-scale 3D models, important components of many studies in science and engineering, are often used to determine morphological characteristics such as shape, surface area and volume. The application of techniques such as stereoscopic scanning electron microscopy on whole objects often results in ‘partial-view’ models with a portion of object not within the field of view thus not captured in the 3D model. The nature and extent of the surface not captured is dependent on the complex interaction of imaging system attributes (e.g. working distance, viewing angle) with object size, shape and morphology. As a result, any simplistic assumptions in estimating whole object surface area or volume can lead to significant errors. In this study, we report on a novel technique to estimate the physical fraction of an object captured in a partial-view 3D model of an otherwise whole object. This allows a more accurate estimate of surface area and volume. Using 3D models, we demonstrate the robustness of this method and the accuracy of surface area and volume estimates relative to true values. (paper)

Measurement of the specific surface area of loose copper deposit by electrochemical methods

Directory of Open Access Journals (Sweden)

E. A. Dolmatova

2016-07-01

Full Text Available In the work the surface area of the electrode with dispersed copper deposit obtained within 30 seconds was evaluated by techniques of chronopotentiometry (CPM and impedance spectroscopy. In method CPM the electrode surface available for measurement depends on the value of the polarizing current. At high currents during the transition time there is a change of surface relief that can not determine the full surface of loose deposit. The electrochemical impedance method is devoid of this shortcoming since the measurements are carried out in indifferent electrolyte in the absence of current. The area measured by the impedance is tens of times higher than the value obtained by chronopotentiometry. It is found that from a solution containing sulfuric acid the deposits form with a high specific surface area. Based on these data it was concluded that the method of impedance spectroscopy can be used to measure in situ the surface area of the dispersed copper deposits.

Estimating surface fluxes over the north Tibetan Plateau area with ASTER imagery

Directory of Open Access Journals (Sweden)

Weiqiang Ma

2009-01-01

Full Text Available Surface fluxes are important boundary conditions for climatological modeling and Asian monsoon system. The recent availability of high-resolution, multi-band imagery from the ASTER (Advanced Space-borne Thermal Emission and Reflection radiometer sensor has enabled us to estimate surface fluxes to bridge the gap between local scale flux measurements using micrometeorological instruments and regional scale land-atmosphere exchanges of water and heat fluxes that are fundamental for the understanding of the water cycle in the Asian monsoon system. A parameterization method based on ASTER data and field observations has been proposed and tested for deriving surface albedo, surface temperature, Normalized Difference Vegetation Index (NDVI, Modified Soil Adjusted Vegetation Index (MSAVI, vegetation coverage, Leaf Area Index (LAI, net radiation flux, soil heat flux, sensible heat flux and latent heat flux over heterogeneous land surface in this paper. As a case study, the methodology was applied to the experimental area of the Coordinated Enhanced Observing Period (CEOP Asia-Australia Monsoon Project (CAMP on the Tibetan Plateau (CAMP/Tibet, located at the north Tibetan Plateau. The ASTER data of 24 July 2001, 29 November 2001 and 12 March 2002 was used in this paper for the case of summer, winter and spring. To validate the proposed methodology, the ground-measured surface variables (surface albedo and surface temperature and land surface heat fluxes (net radiation flux, soil heat flux, sensible heat flux and latent heat flux were compared to the ASTER derived values. The results show that the derived surface variables and land surface heat fluxes in three different months over the study area are in good accordance with the land surface status. Also, the estimated land surface variables and land surface heat fluxes are in good accordance with ground measurements, and all their absolute percentage difference (APD is less than 10% in the validation sites

Environmental and geochemical assessment of surface sediments on irshansk ilmenite deposit area

Directory of Open Access Journals (Sweden)

Наталия Олеговна Крюченко

2015-03-01

Full Text Available It is revealed the problem of pollution of surface sediments of Irshansk ilmenite deposit area of various chemical elements hazard class (Mn, V, Ba, Ni, Co, Cr, Mo, Cu, Pb, Zn. It is determined its average content in surface sediments of various functional areas (forest and agricultural land, flood deposits, reclaimed land, calculated geochemical criteria, so given ecological and geochemical assessment of area

Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields

Energy Technology Data Exchange (ETDEWEB)

Genenko, Yuri A., E-mail: genenko@mm.tu-darmstadt.de; Hirsch, Ofer [Technische Universität Darmstadt, Darmstadt (Germany); Erhart, Paul [Chalmers University of Technology, Gothenburg (Sweden)

2014-03-14

Nonlinear screening of electric depolarization fields, generated by a stripe domain structure in a ferroelectric grain of a polycrystalline material, is studied within a semiconductor model of ferroelectrics. It is shown that the maximum strength of local depolarization fields is rather determined by the electronic band gap than by the spontaneous polarization magnitude. Furthermore, field screening due to electronic band bending and due to presence of intrinsic defects leads to asymmetric space charge regions near the grain boundary, which produce an effective dipole layer at the surface of the grain. This results in the formation of a potential difference between the grain surface and its interior of the order of 1 V, which can be of either sign depending on defect transition levels and concentrations. Exemplary acceptor doping of BaTiO{sub 3} is shown to allow tuning of the said surface potential in the region between 0.1 and 1.3 V.

30 CFR 785.19 - Surface coal mining and reclamation operations on areas or adjacent to areas including alluvial...

Science.gov (United States)

2010-07-01

... alluvial valley floor exists if it finds that— (i) Unconsolidated streamlaid deposits holding streams are... on areas or adjacent to areas including alluvial valley floors in the arid and semiarid areas west of....19 Surface coal mining and reclamation operations on areas or adjacent to areas including alluvial...

Land Use Change and Agricultural Land Fragmentation due to Anthropogenic Activities in an Hot Spot Area: A Case Study for Thrace Region of Turkey

Science.gov (United States)

Altürk, Bahadır; Konukcu, Fatih

2017-04-01

Agricultural lands that supply food, energy and ecosystem services for human life have been lost due to anthropogenic activities such as construction of roads, urban and industry areas. The significant reasons for the increase of artificial surfaces were poorly planned economic decisions by the government and internal migration due to this poorly planning. Unplanned urban sprawl also give rise to land fragmentation. Fragmentation of agricultural land affects both the agricultural production capacity and rural sustainable employment. In this study: i) Land use changes between 1990-2014 period were assessed using remotely sensed data and ii) Spatial and temporal agricultural land fragmentation were investigated using landscape pattern indice (effective mesh size), Morphological Spatial Pattern Analysis (MSPA) and Entropy method for 25 years period. The selected"hot spot" study area is located on east Thrace region of Turkey, being the service and industrial development zone where agricultural activities, water resources and natural habitat have been damaged due to rapid urban and industrial development for about 25 years. The results showed that agricultural lands decreased 6.44%, urban areas increased 111.68% and industry areas increased 251.19% during this 25 years period. Additionally, fragmentation analyses demonstrated that core agricultural areas sharply decreased and relative fragmentation (effective mesh size) increased from 50.68% to 56.77% during 1990 and 2014.

Long-term studies on the effects of nonvolatile organic compounds on porous media surface areas.

Science.gov (United States)

Khachikian, Crist S; Harmon, Thomas C

2002-01-01

This paper investigates the long-term behavior of porous media contaminated by nonvolatile organic compounds (NVOC) in terms of specific interfacial surface area. Specifically, a natural sand, Moffett sand (MS), was contaminated with naphthalene and the surface area was measured repeatedly over time using nitrogen adsorption-desorption techniques. A field-contaminated sand affected by lamp-black material (LB) from former manufactured gas plant operations was also studied. Lampblack is a carbonaceous skeleton containing polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons. It is hypothesized that soils contaminated by these types of chemicals will exhibit significantly less surface area than their clean counterparts. The surface areas for the contaminated MS samples increased toward their clean-MS values during the 700-h aging period, but achieved the clean values only after pentane extraction or heating at 60 degrees C. Heating at 50 degrees C failed to achieve a similar recovery of the clean-MS surface area value. Nonspecific mass loss tracked the increase in surface area as indirect evidence that naphthalene loss was the cause of the surface area increase. For the LB samples, aging at 100 degrees C produced a slight decrease in surface area and mass while aging at 250 degrees C caused the surface area to increase roughly threefold while the mass decreased by approximately 1%. These results suggest that, under moderate heating and over the time scale of this investigation, there is a redistribution of the complex contaminant mixture on the solid matrix. Greater temperatures remove mass more efficiently and therefore exhibited the surface area increase expected in this experiment.

Evolution of the Contact Area with Normal Load for Rough Surfaces: from Atomic to Macroscopic Scales.

Science.gov (United States)

Huang, Shiping

2017-11-13

The evolution of the contact area with normal load for rough surfaces has great fundamental and practical importance, ranging from earthquake dynamics to machine wear. This work bridges the gap between the atomic scale and the macroscopic scale for normal contact behavior. The real contact area, which is formed by a large ensemble of discrete contacts (clusters), is proven to be much smaller than the apparent surface area. The distribution of the discrete contact clusters and the interaction between them are key to revealing the mechanism of the contacting solids. To this end, Green's function molecular dynamics (GFMD) is used to study both how the contact cluster evolves from the atomic scale to the macroscopic scale and the interaction between clusters. It is found that the interaction between clusters has a strong effect on their formation. The formation and distribution of the contact clusters is far more complicated than that predicted by the asperity model. Ignorance of the interaction between them leads to overestimating the contacting force. In real contact, contacting clusters are smaller and more discrete due to the interaction between the asperities. Understanding the exact nature of the contact area with the normal load is essential to the following research on friction.

A method of analyzing rectal surface area irradiated and rectal complications in prostate conformal radiotherapy

International Nuclear Information System (INIS)

Lu Yong; Song, Paul Y.; Li Shidong; Spelbring, Danny R.; Vijayakumar, Srinivasan; Haraf, Daniel J.; Chen, George T.Y.

1995-01-01

Purpose: To develop a method of analyzing rectal surface area irradiated and rectal complications in prostate conformal radiotherapy. Methods and Materials: Dose-surface histograms of the rectum, which state the rectal surface area irradiated to any given dose, were calculated for a group of 27 patients treated with a four-field box technique to a total (tumor minimum) dose ranging from 68 to 70 Gy. Occurrences of rectal toxicities as defined by the Radiation Therapy Oncology Group (RTOG) were recorded and examined in terms of dose and rectal surface area irradiated. For a specified end point of rectal complication, the complication probability was analyzed as a function of dose irradiated to a fixed rectal area, and as a function of area receiving a fixed dose. Lyman's model of normal tissue complication probability (NTCP) was used to fit the data. Results: The observed occurrences of rectal complications appear to depend on the rectal surface area irradiated to a given dose level. The patient distribution of each toxicity grade exhibits a maximum as a function of percentage surface area irradiated, and the maximum moves to higher values of percentage surface area as the toxicity grade increases. The dependence of the NTCP for the specified end point on dose and percentage surface area irradiated was fitted to Lyman's NTCP model with a set of parameters. The curvature of the NTCP as a function of the surface area suggests that the rectum is a parallel structured organ. Conclusions: The described method of analyzing rectal surface area irradiated yields interesting insight into understanding rectal complications in prostate conformal radiotherapy. Application of the method to a larger patient data set has the potential to facilitate the construction of a full dose-surface-complication relationship, which would be most useful in guiding clinical practice

Quality factor due to roughness scattering of shear horizontal surface acoustic waves in nanoresonators

NARCIS (Netherlands)

Palasantzas, G.

2008-01-01

In this work we study the quality factor associated with dissipation due to scattering of shear horizontal surface acoustic waves by random self-affine roughness. It is shown that the quality factor is strongly influenced by both the surface roughness exponent H and the roughness amplitude w to

A high surface area Zr(IV)-based metal–organic framework showing stepwise gas adsorption and selective dye uptake

Energy Technology Data Exchange (ETDEWEB)

Lv, Xiu-Liang [Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing 100124 (China); Tong, Minman; Huang, Hongliang [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wang, Bin; Gan, Lei [Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing 100124 (China); Yang, Qingyuan [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhong, Chongli [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Li, Jian-Rong, E-mail: jrli@bjut.edu.cn [Beijing Key Laboratory for Green Catalysis and Separation, Department of Chemistry and Chemical Engineering, Beijing University of Technology, Beijing 100124 (China); State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

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 as 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.

High-surface-area active carbon

International Nuclear Information System (INIS)

O'Grady, T.M.; Wennerberg, A.N.

1986-01-01

This paper describes the preparation and properties of a unique active carbon having exceptionally high surface areas, over 2500 m 2 /gm, and extraordinary adsorptive capacities. The carbon is made by a direct chemical activation route in which petroleum coke or other carbonaceous sources are reacted with excess potassium hydroxide at 400 0 to 500 0 C to an intermediate product that is subsequently pyrolyzed at 800 0 to 900 0 C to active carbon containing potassium salts. These are removed by water washing and the carbon is dried to produce a powdered product. A granular carbon can also be made by further processing the powdered carbon by using specialized granulation techniques. Typical properties of the carbon include Iodine Numbers of 3000 to 3600, methylene blue adsorption of 650 to 750 mg/gm, pore volumes of 2.0 to 2.6 cc/gm and less than 3.0% ash. This carbon's high adsorption capacities make it uniquely suited for numerous demanding applications in the medical area, purifications, removal of toxic substances, as catalyst carriers, etc

Spectral theory of infinite-area hyperbolic surfaces

CERN Document Server

Borthwick, David

2016-01-01

This text introduces geometric spectral theory in the context of infinite-area Riemann surfaces, providing a comprehensive account of the most recent developments in the field. For the second edition the context has been extended to general surfaces with hyperbolic ends, which provides a natural setting for development of the spectral theory while still keeping technical difficulties to a minimum. All of the material from the first edition is included and updated, and new sections have been added. Topics covered include an introduction to the geometry of hyperbolic surfaces, analysis of the resolvent of the Laplacian, scattering theory, resonances and scattering poles, the Selberg zeta function, the Poisson formula, distribution of resonances, the inverse scattering problem, Patterson-Sullivan theory, and the dynamical approach to the zeta function. The new sections cover the latest developments in the field, including the spectral gap, resonance asymptotics near the critical line, and sharp geometric constan...

Electrochemical Properties of High Surface Area Vanadium Oxide Aerogels

National Research Council Canada - National Science Library

Dong, Winny

2001-01-01

.... Traditional composite electrode structures have prevented truly quantitative analysis of surface area effects in nanoscale battery materials, as well as a study of their innate electrochemical behavior...

Surface area changes of Himalayan ponds as a proxy of hydrological climate-driven fluctuations

Science.gov (United States)

Salerno, Franco; Thakuri, Sudeep; Guyennon, Nicolas; Viviano, Gaetano; Tartari, Gianni

2016-04-01

The meteorological measurements at high-elevations of the Himalayan range are scarce due to the harsh conditions of these environments which limit the suitable maintenance of weather stations. As a consequence, the meager knowledge on how the climate is changed in the last decades at Himalayan high-elevations sets a serious limit upon the interpretation of relationships between causes and recent observed effects on the cryosphere. Although the glaciers masses reduction in Himalaya is currently sufficiently well described, how changes in climate drivers (precipitation and temperature) have influenced the melting and shrinkage processes are less clear. Consequently, the uncertainty related to the recent past amplifies when future forecasts are done, both for climate and impacts. In this context, a substantial body of research has already demonstrated the high sensitivity of lakes and ponds to climate. Some climate-related signals are highly visible and easily measurable in lakes. For example, climate-driven fluctuations in lake surface area have been observed in many remote sites. On interior Tibetan Plateau the lake growth since the late 1990s is mainly attributed to increased regional precipitation and weakened evaporation. Differently, other authors attribute at the observed increases of lake surfaces at the enhanced glacier melting. In our opinion these divergences found in literature are due to the type of glacial lakes considered in the study and in particular their relationship with glaciers. In general, in Himalaya three types of glacial lakes can be distinguished: (i) lakes that are not directly connected with glaciers, but that may have a glacier located in their basin (unconnected glacial lakes); (ii) supraglacial lakes, which develop on the surface of the glacier downstream; or (iii) proglacial lakes, which are moraine-dammed lakes that are in contact with the glacier front. Some of these lakes store large quantities of water and are susceptible to GLOFs

Low-Surface-Area Hard Carbon Anode for Na-Ion Batteries via Graphene Oxide as a Dehydration Agent

Energy Technology Data Exchange (ETDEWEB)

Luo, W; Bommier, C; Jian, ZL; Li, X; Carter, R; Vail, S; Lu, YH; Lee, JJ; Ji, XL

2015-02-04

Na-ion batteries are emerging as one of the most promising energy storage technologies, particularly for grid-level applications. Among anode candidate materials, hard carbon is very attractive due to its high capacity and low cost. However, hard carbon anodes often suffer a low first-cycle Coulombic efficiency and fast capacity fading. In this study, we discover that doping graphene oxide into sucrose, the precursor for hard carbon, can effectively reduce the specific surface area of hard carbon to as low as 5.4 m(2)/g. We further reveal that such doping can effectively prevent foaming during caramelization of sucrose and extend the pyrolysis burnoff of sucrose caramel over a wider temperature range. The obtained low-surface-area hard carbon greatly improves the first-cycle Coulombic efficiency from 74% to 83% and delivers a very stable cyclic life with 95% of capacity retention after 200 cycles.

Comparison of diffusion charging and mobility-based methods for measurement of aerosol agglomerate surface area.

Science.gov (United States)

Ku, Bon Ki; Kulkarni, Pramod

2012-05-01

We compare different approaches to measure surface area of aerosol agglomerates. The objective was to compare field methods, such as mobility and diffusion charging based approaches, with laboratory approach, such as Brunauer, Emmett, Teller (BET) method used for bulk powder samples. To allow intercomparison of various surface area measurements, we defined 'geometric surface area' of agglomerates (assuming agglomerates are made up of ideal spheres), and compared various surface area measurements to the geometric surface area. Four different approaches for measuring surface area of agglomerate particles in the size range of 60-350 nm were compared using (i) diffusion charging-based sensors from three different manufacturers, (ii) mobility diameter of an agglomerate, (iii) mobility diameter of an agglomerate assuming a linear chain morphology with uniform primary particle size, and (iv) surface area estimation based on tandem mobility-mass measurement and microscopy. Our results indicate that the tandem mobility-mass measurement, which can be applied directly to airborne particles unlike the BET method, agrees well with the BET method. It was also shown that the three diffusion charging-based surface area measurements of silver agglomerates were similar within a factor of 2 and were lower than those obtained from the tandem mobility-mass and microscopy method by a factor of 3-10 in the size range studied. Surface area estimated using the mobility diameter depended on the structure or morphology of the agglomerate with significant underestimation at high fractal dimensions approaching 3.

Surface Rupture Effects on Earthquake Moment-Area Scaling Relations

Science.gov (United States)

Luo, Yingdi; Ampuero, Jean-Paul; Miyakoshi, Ken; Irikura, Kojiro

2017-09-01

Empirical earthquake scaling relations play a central role in fundamental studies of earthquake physics and in current practice of earthquake hazard assessment, and are being refined by advances in earthquake source analysis. A scaling relation between seismic moment ( M 0) and rupture area ( A) currently in use for ground motion prediction in Japan features a transition regime of the form M 0- A 2, between the well-recognized small (self-similar) and very large (W-model) earthquake regimes, which has counter-intuitive attributes and uncertain theoretical underpinnings. Here, we investigate the mechanical origin of this transition regime via earthquake cycle simulations, analytical dislocation models and numerical crack models on strike-slip faults. We find that, even if stress drop is assumed constant, the properties of the transition regime are controlled by surface rupture effects, comprising an effective rupture elongation along-dip due to a mirror effect and systematic changes of the shape factor relating slip to stress drop. Based on this physical insight, we propose a simplified formula to account for these effects in M 0- A scaling relations for strike-slip earthquakes.

Land surface temperature representativeness in a heterogeneous area through a distributed energy-water balance model and remote sensing data

Directory of Open Access Journals (Sweden)

C. Corbari

2010-10-01

Full Text Available Land surface temperature is the link between soil-vegetation-atmosphere fluxes and soil water content through the energy water balance. This paper analyses the representativeness of land surface temperature (LST for a distributed hydrological water balance model (FEST-EWB using LST from AHS (airborne hyperspectral scanner, with a spatial resolution between 2–4 m, LST from MODIS, with a spatial resolution of 1000 m, and thermal infrared radiometric ground measurements that are compared with the representative equilibrium temperature that closes the energy balance equation in the distributed hydrological model.

Diurnal and nocturnal images are analyzed due to the non stable behaviour of the thermodynamic temperature and to the non linear effects induced by spatial heterogeneity.

Spatial autocorrelation and scale of fluctuation of land surface temperature from FEST-EWB and AHS are analysed at different aggregation areas to better understand the scale of representativeness of land surface temperature in a hydrological process.

The study site is the agricultural area of Barrax (Spain that is a heterogeneous area with a patchwork of irrigated and non irrigated vegetated fields and bare soil. The used data set was collected during a field campaign from 10 to 15 July 2005 in the framework of the SEN2FLEX project.

On semiautomatic estimation of surface area

DEFF Research Database (Denmark)

Dvorak, J.; Jensen, Eva B. Vedel

2013-01-01

and the surfactor. For ellipsoidal particles, it is shown that the flower estimator is equal to the pivotal estimator based on support function measurements along four perpendicular rays. This result makes the pivotal estimator a powerful approximation to the flower estimator. In a simulation study of prolate....... If the segmentation is correct the estimate is computed automatically, otherwise the expert performs the necessary measurements manually. In case of convex particles we suggest to base the semiautomatic estimation on the so-called flower estimator, a new local stereological estimator of particle surface area....... For convex particles, the estimator is equal to four times the area of the support set (flower set) of the particle transect. We study the statistical properties of the flower estimator and compare its performance to that of two discretizations of the flower estimator, namely the pivotal estimator...

Digital photography and transparency-based methods for measuring wound surface area.

Science.gov (United States)

Bhedi, Amul; Saxena, Atul K; Gadani, Ravi; Patel, Ritesh

2013-04-01

To compare and determine a credible method of measurement of wound surface area by linear, transparency, and photographic methods for monitoring progress of wound healing accurately and ascertaining whether these methods are significantly different. From April 2005 to December 2006, 40 patients (30 men, 5 women, 5 children) admitted to the surgical ward of Shree Sayaji General Hospital, Baroda, had clean as well as infected wound following trauma, debridement, pressure sore, venous ulcer, and incision and drainage. Wound surface areas were measured by these three methods (linear, transparency, and photographic methods) simultaneously on alternate days. The linear method is statistically and significantly different from transparency and photographic methods (P value transparency and photographic methods (P value >0.05). Photographic and transparency methods provided measurements of wound surface area with equivalent result and there was no statistically significant difference between these two methods.

Surface behaviour of first-wall materials due to the synergistic effect of helium and hydrogen isotopes

International Nuclear Information System (INIS)

Abramov, E.; Moreno, D.; Solovioff, G.; Eliezer, D.

1994-01-01

Scanning electron microscopy has been used to investigate changes in surface morphology due to helium implantation and hydrogen charging. Pure polycrystalline nickel, OFHC copper and Cu-1.8Be-0.2Co (CAD 172) alloy have been studied. The influence of helium implantation parameters on blister formation and growth was investigated. Hydrogen charging (cathodic or thermal-gas) was found to lower the helium content needed for blistering and surface exfoliation. The effect of heating, carried out after hydrogen charging, was also studied. For the copper samples, hydrogen damage was produced by oxide reduction at the oxide-metal interface. This damage was found to be lower when the sputtering due to helium implantation increased. The CuBe alloy showed a greater hydrogen resistance due to the stability of the surface BeO. ((orig.))

Surface-Enhanced Raman Spectroscopy Based Quantitative Bioassay on Aptamer-Functionalized Nanopillars Using Large-Area Raman Mapping

DEFF Research Database (Denmark)

Yang, Jaeyoung; Palla, Mirko; Bosco, Filippo

2013-01-01

Surface-enhanced Raman spectroscopy (SERS) has been used in a variety of biological applications due to its high sensitivity and specificity. Here, we report a SERS-based biosensing approach for quantitative detection of biomolecules. A SERS substrate bearing gold-decorated silicon nanopillars......-to-spot variation in conventional SERS quantification. Furthermore, we have developed an analytical model capable of predicting experimental intensity distributions on the substrates for reliable quantification of biomolecules. Lastly, we have calculated the minimum needed area of Raman mapping for efficient...

Gender differences in knee joint cartilage thickness, volume and articular surface areas: assessment with quantitative three-dimensional MR imaging

International Nuclear Information System (INIS)

Faber, S.C.; Reiser, M.; Englmeier, K.H.

2001-01-01

Objective: To compare the cartilage thickness, volume, and articular surface areas of the knee joint between young healthy, non-athletic female and male individuals. Subjects and design. MR imaging was performed in 18 healthy subjects without local or systemic joints disease (9 female, age 22.3±2.4 years, and 9 male, age 22.2.±1.9 years), using a fat-suppressed FLASH 3D pulse sequence (TR=41 ms, TE=11 ms, FA=30 ) with sagittal orientation and a spatial resolution of 2x0.31x0.31 mm 3 . After three-dimensional reconstruction and triangulation of the knee joint cartilage plates, the cartilage thickness (mean and maximal), volume, and size of the articular surface area were quantified, independent of the original section orientation. Results and conclusions: Women displayed smaller cartilage volumes than men, the percentage difference ranging from 19.9% in the patella, to 46.6% in the medial tibia. The gender differences of the cartilage thickness were smaller, ranging from 2.0% in the femoral trochlea to 13.3% in the medial tibia for the mean thickness, and from 4.3% in the medial femoral condyle to 18.3% in the medial tibia for the maximal cartilage thickness. The differences between the cartilage surface areas were similar to those of the volumes, with values ranging from 21.0% in the femur to 33.4% in the lateral tibia. Gender differences could be reduced for cartilage volume and surface area when normalized to body weight and body weight x body height. The study demonstrates significant gender differences in cartilage volume and surface area of men and women, which need to be taken into account when retrospectively estimating articular cartilage loss in patients with symptoms of degenerative joint disease. Differences in cartilage volume are primarily due to differences in joint surface areas (epiphyseal bone size), not to differences in cartilage thickness. (orig.)

Isopleths of surface air concentration and surface air kerma rate due to a radioactive cloud released from a stack (3)

International Nuclear Information System (INIS)

Tachibana, Haruo; Kikuchi, Masamitsu; Sekita, Tsutomu; Yamaguchi, Takenori

2004-06-01

This report is a revised edition of 'Isopleths of Surface Air Concentration and Surface Air Absorbed Dose Rate due to a Radioactive Cloud Released from a Stack(II) '(JAERI-M 90-206) and based on the revised Nuclear Safety Guidelines reflected the ICRP1990 Recommendation. Characteristics of this report are the use of Air Karma Rate (Gy/h) instead of Air Absorbed Dose Rate (Gy/h), and the record of isopleths of surface air concentration and surface air karma rate on CD-ROM. These recorded data on CD-ROM can be printed out on paper and/or pasted on digital map by personal computer. (author)

Nanoporous Ni with High Surface Area for Potential Hydrogen Storage Application.

Science.gov (United States)

Zhou, Xiaocao; Zhao, Haibo; Fu, Zhibing; Qu, Jing; Zhong, Minglong; Yang, Xi; Yi, Yong; Wang, Chaoyang

2018-06-01

Nanoporous metals with considerable specific surface areas and hierarchical pore structures exhibit promising applications in the field of hydrogen storage, electrocatalysis, and fuel cells. In this manuscript, a facile method is demonstrated for fabricating nanoporous Ni with a high surface area by using SiO₂ aerogel as a template, i.e., electroless plating of Ni into an SiO₂ aerogel template followed by removal of the template at moderate conditions. The effects of the prepared conditions, including the electroless plating time, temperature of the structure, and the magnetism of nanoporous Ni are investigated in detail. The resultant optimum nanoporous Ni with a special 3D flower-like structure exhibited a high specific surface area of about 120.5 m²/g. The special nanoporous Ni exhibited a promising prospect in the field of hydrogen storage, with a hydrogen capacity of 0.45 wt % on 4.5 MPa at room temperature.

Evaluating polymer degradation with complex mixtures using a simplified surface area method.

Science.gov (United States)

Steele, Kandace M; Pelham, Todd; Phalen, Robert N

2017-09-01

Chemical-resistant gloves, designed to protect workers from chemical hazards, are made from a variety of polymer materials such as plastic, rubber, and synthetic rubber. One material does not provide protection against all chemicals, thus proper polymer selection is critical. Standardized testing, such as chemical degradation tests, are used to aid in the selection process. The current methods of degradation ratings based on changes in weight or tensile properties can be expensive and data often do not exist for complex chemical mixtures. There are hundreds of thousands of chemical products on the market that do not have chemical resistance data for polymer selection. The method described in this study provides an inexpensive alternative to gravimetric analysis. This method uses surface area change to evaluate degradation of a polymer material. Degradation tests for 5 polymer types against 50 complex mixtures were conducted using both gravimetric and surface area methods. The percent change data were compared between the two methods. The resulting regression line was y = 0.48x + 0.019, in units of percent, and the Pearson correlation coefficient was r = 0.9537 (p ≤ 0.05), which indicated a strong correlation between percent weight change and percent surface area change. On average, the percent change for surface area was about half that of the weight change. Using this information, an equivalent rating system was developed for determining the chemical degradation of polymer gloves using surface area.

Assessment of surface and subsurface ground disturbance due to underground mining

International Nuclear Information System (INIS)

Khair, A.W.

1994-01-01

This paper presents highlights of the research carried out at West Virginia University in order to assess surface and subsurface ground disturbance due to longwall mining. Extensive instrumentation and measurements have been made over three longwall mines in northern West Virginia during a three-year period. Various monitoring techniques including full profile borehole extensometer, full profile borehole inclinometers, time domain reflectometry, sonic reflection technique, a unique mechanical grouting method, photographic and visual observations, standard surveying, and water-level measurements were utilized. The paper's emphasis is first on surface ground movement and its impact on integrity of surface ground and structures and second on type and magnitude of subsurface ground movements associated with mine geometry and geology. A subsidence prediction model based on implementation of both mechanisms of ground movement around the excavation and the geologic and geotechnical properties of the rock/coal surrounding the excavation has been developed. 8 refs., 14 figs., 1 tab

Optimization of operating variables for production of ultra-fine talc in a stirred mill. Specific surface area investigations

Directory of Open Access Journals (Sweden)

Toraman Oner Yusuf

2016-01-01

Full Text Available Due to its properties such as chemical inertness, softness, whiteness, high thermal conductivity, low electrical conductivity and adsorption properties talc has wide industrial applications in paper, cosmetics, paints, polymer, ceramics, refractory materials and pharmaceutical. The demand for ultra-fine talc is emerging which drives the mineral industry to produce value added products. In this study, it was investigated how certain grinding parameters such as mill speed, ball filling ratio, powder filling ratio and grinding time of dry stirred mill affect grindability of talc ore (d97=127 μm. A series of laboratory experiments using a 24 full factorial design was conducted to determine the optimal operational parameters of a stirred mill in order to minimize the specific surface area. The main and interaction effects on the volume specific surface area (SV, m2.cm−3 of the ground product were evaluated using the Yates analysis. Under the optimal conditions at the stirrer speed of 600 rpm, grinding time of 20 min, sample mass of 5% and ball ratio of 70%, the resulting talc powder had larger volume specific surface area (i.e., 3.48 m2.cm−3 than the starting material (i.e., 1.84 m2.cm−3.

Temporal sea-surface gravity changes observed near the source area prior to the 2011 Tohoku earthquake

Science.gov (United States)

Nakamura, T.; Tsuboi, S.

2013-12-01

Recent seismological studies suggested subsurface activities preceding the 2011 Tohoku earthquake; the occurrence of migration of seismicity (Kato et al., 2012) and slow slip events (Ito et al., 2013) in and around the source area one month before the mainshock. In this study, we investigated sea-surface gravity changes observed by the shipboard gravimeter mounted on research vessels before the mainshock. The vessels incidentally passed through the source area along almost the same cruise track twice, four months before and one month before the mainshock. Comparing the sea surface gravity in the former track with that in the latter after Bouguer correction, we find the gravity changes of approximately 7 mGal in coseismic slip areas near the trench axis during the three months. We find these gravity changes even in the crossing areas of the cruise tracks where seafloor topographies have no differences between the tracks. We also find that the topographic differences show positive changes but the gravity changes negative ones in other areas, which is a negative correlation inconsistent with the theoretical relationship between the topographic difference and the gravity change. These mean that the differences of seafloor topographies due to differences between the two cruise tracks are not main causes of the observed gravity changes there. The changes cannot also be explained by drifts of the gravimeter and geostrophic currents. Although we have not had any clear evidences, we speculate that the possible cause may be density increases around the seismogenic zone or uplifts of seafloor in order to explain the changes of this size. We estimate the density increases of 1.0 g/cm**3 in a disk with a radius of 40 km and a width of 200 m or the uplifts of several tens of meters in seafloor areas for the observed gravity changes. Our results indicate that sea-surface gravity observations may be one of valid approaches to monitor the approximate location of a possible great

Preparation of MgO with High Surface Area, and Modification of Its Pore Characteristics

Energy Technology Data Exchange (ETDEWEB)

Lee, Moon Hee; Park, Dong Gon [Sookmyung Women' s University, Seoul (Korea, Republic of)

2003-10-15

Thermal decomposition of hydrated surface layer of Mg(OH){sub 2} at 500 .deg. C in vacuum turned non-porous MgO into porous one with high surface area of around 270 m{sup 2}/g. Most of its surface area, 74 %, was from micropores, and rest of it was from mesopores in wedge-shaped slits, exhibiting bimodal size distribution centered around 30 and 90 A. Rehydration followed by subsequent dehydration at 300 .deg. C in dynamic vacuum further raised the surface area to 340 m{sup 2}/g. Fraction of microporous surface area was increased to 93%, and the shape of the mesopores was modified into parallel slits with a specific dimension of 32 A. Application of Fe{sub 2}O{sub 3} over MgO via iron complex formation did not alter the pore characteristics of MgO core, except slightly increased pore dimension. Over the course of the modification, Fe{sub 2}O{sub 3} stayed on the surface possibly via spill-over reaction.

Adsorption of water vapour and the specific surface area of arctic zone soils (Spitsbergen)

Science.gov (United States)

Cieśla, Jolanta; Sokołowska, Zofia; Witkowska-Walczak, Barbara; Skic, Kamil

2018-01-01

Water vapour/nitrogen adsorption were investigated and calculated the specific surface areas of arctic-zone soil samples (Turbic Cryosols) originating from different micro-relief forms (mud boils, cell forms and sorted circles) and from different depths. For the characterisation of the isotherms obtained for arctic soils, the Brunauer-Emmet-Teller model was then compared with the two other models (Aranovich-Donohue and Guggenheim-Anderson-de Boer) which were developed from Brunauer-Emmet-Teller. Specific surface area was calculated using the Brunauer-Emmet-Teller model at p p0-1 range of 0.05-0.35 for the water vapour desorption and nitrogen adsorption isotherms. The values of total specific surface area were the highest in Cryosols on mud boils, lower on cell forms, and the lowest on sorted circles. Such tendency was observed for the results obtained by both the water vapour and nitrogen adsorption. The differences in the values of specific surface area at two investigated layers were small. High determination coefficients were obtained for relationships between the specific surface areas and contents of clay and silt fraction in Cryosols. No statistically significant correlation between the total carbon amount and the values of specific surface area in Cryosols has been found.

High surface area V-Mo-N materials synthesized from amine intercalated foams

International Nuclear Information System (INIS)

Krawiec, Piotr; Narayan Panda, Rabi; Kockrick, Emanuel; Geiger, Dorin; Kaskel, Stefan

2008-01-01

Nanocrystalline ternary V-Mo nitrides were prepared via nitridation of amine intercalated oxide foams or bulk ternary oxides. Specific surface areas were in the range between 40 and 198 m 2 g -1 and strongly depended on the preparation method (foam or bulk oxide). Foamed precursors were favorable for vanadium rich materials, while for molybdenum rich samples bulk ternary oxides resulted in higher specific surface areas. The materials were characterized via nitrogen physisorption at 77 K, X-ray diffraction patterns, electron microscopy, and elemental analysis. - Graphical abstract: Nanocrystalline ternary V-Mo nitrides were prepared via nitridation of amine intercalated oxide foams or bulk ternary oxides. Foamed precursors were favorable for vanadium rich materials, while for molybdenum rich samples bulk ternary oxides resulted in higher specific surface areas

A longitudinal study: changes in cortical thickness and surface area during pubertal maturation.

Directory of Open Access Journals (Sweden)

Megan M Herting

Full Text Available Sex hormones have been shown to contribute to the organization and function of the brain during puberty and adolescence. Moreover, it has been suggested that distinct hormone changes in girls versus boys may contribute to the emergence of sex differences in internalizing and externalizing behavior during adolescence. In the current longitudinal study, the influence of within-subject changes in puberty (physical and hormonal on cortical thickness and surface area was examined across a 2-year span, while controlling for age. Greater increases in Tanner Stage predicted less superior frontal thinning and decreases in precuneus surface area in both sexes. Significant Tanner Stage and sex interactions were also seen, with less right superior temporal thinning in girls but not boys, as well as greater decreases in the right bank of the superior temporal sulcus surface area in boys compared to girls. In addition, within-subject changes in testosterone over the 2-year follow-up period were found to relate to decreases in middle superior frontal surface area in boys, but increases in surface area in girls. Lastly, larger increases in estradiol in girls predicted greater middle temporal lobe thinning. These results show that within-subject physical and hormonal markers of puberty relate to region and sex-specific changes in cortical development across adolescence.

A longitudinal study: changes in cortical thickness and surface area during pubertal maturation.

Science.gov (United States)

Herting, Megan M; Gautam, Prapti; Spielberg, Jeffrey M; Dahl, Ronald E; Sowell, Elizabeth R

2015-01-01

Sex hormones have been shown to contribute to the organization and function of the brain during puberty and adolescence. Moreover, it has been suggested that distinct hormone changes in girls versus boys may contribute to the emergence of sex differences in internalizing and externalizing behavior during adolescence. In the current longitudinal study, the influence of within-subject changes in puberty (physical and hormonal) on cortical thickness and surface area was examined across a 2-year span, while controlling for age. Greater increases in Tanner Stage predicted less superior frontal thinning and decreases in precuneus surface area in both sexes. Significant Tanner Stage and sex interactions were also seen, with less right superior temporal thinning in girls but not boys, as well as greater decreases in the right bank of the superior temporal sulcus surface area in boys compared to girls. In addition, within-subject changes in testosterone over the 2-year follow-up period were found to relate to decreases in middle superior frontal surface area in boys, but increases in surface area in girls. Lastly, larger increases in estradiol in girls predicted greater middle temporal lobe thinning. These results show that within-subject physical and hormonal markers of puberty relate to region and sex-specific changes in cortical development across adolescence.

Ultrahigh surface area carbon from carbonated beverages: Combining self-templating process and in situ activation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Pengfei; Zhang, Zhiyong; Chen, Jihua; Dai, Sheng

2015-11-01

Ultrahigh surface area carbons (USACs, e.g., >2000 m2/g) are attracting tremendous attention due to their outstanding performance in energy-related applications. The state-of-art approaches to USACs involve templating or activation methods and all these techniques show certain drawbacks. In this work, a series of USACs with specific surface areas up to 3633 m2/g were prepared in two steps: hydrothermal carbonization (200 °C) of carbonated beverages (CBs) and further thermal treatment in nitrogen (600–1000 °C). The rich inner porosity is formed by a self-templated process during which acids and polyelectrolyte sodium salts in the beverage formulas make some contribution. This strategy covers various CBs such as Coca Cola®, Pepsi Cola®, Dr. Pepper®, and Fanta® and it enables an acceptable product yield (based on sugars), for example: 21 wt% for carbon (2940 m2/g) from Coca Cola®. Being potential electrode materials for supercapacitors, those carbon materials possessed a good specific capacitance (57.2–185.7 F g-1) even at a scan rate of 1000 mV s-1. Thus, a simple and efficient strategy to USACs has been presented.

Infinitesimal-area 2D radiative analysis using parametric surface representation, through NURBS

Energy Technology Data Exchange (ETDEWEB)

Daun, K J; Hollands, K G.T.

1999-07-01

The use of form factors in the treatment of radiant enclosures requires that the radiosity and surface properties be treated as uniform over finite areas. This restriction can be relaxed by applying an infinitesimal-area analysis, where the radiant exchange is taken to be between infinitesimal areas, rather than finite areas. This paper presents a generic infinitesimal-area formulation that can be applied to two-dimensional enclosure problems. (Previous infinitesimal-area analyses have largely been restricted to specific, one-dimensional problems.) Specifically, the paper shows how the analytical expression for the kernel of the integral equation can be obtained without human intervention, once the enclosure surface has been defined parametrically. This can be accomplished by using a computer algebra package or by using NURBS algorithms, which are the industry standard for the geometrical representations used in CAD-CAM codes. Once the kernel has been obtained by this formalism, the 2D integral equation can be set up and solved numerically. The result is a single general-purpose infinitesimal-area analysis code that can proceed from surface specification to solution. The authors have implemented this 2D code and tested it on 1D problems, whose solutions have been given in the literature, obtaining agreement commensurate with the accuracy of the published solutions.

THE EFFECTS OF BUILT-UP AND GREEN AREAS ON THE LAND SURFACE TEMPERATURE OF THE KUALA LUMPUR CITY

Directory of Open Access Journals (Sweden)

N. A. Isa

2017-10-01

Full Text Available A common consequence of rapid and uncontrollable urbanization is Urban Heat Island (UHI. It occurs due to the negligence on climate behaviour which degrades the quality of urban climate condition. Recently, addressing urban climate in urban planning through mapping has received worldwide attention. Therefore, the need to identify the significant factors is a must. This study aims to analyse the relationships between Land Surface Temperature (LST and two urban parameters namely built-up and green areas. Geographical Information System (GIS and remote sensing techniques were used to prepare the necessary data layers required for this study. The built-up and the green areas were extracted from Landsat 8 satellite images either using the Normalized Difference Built-Up Index (NDBI, Normalized Difference Vegetation Index (NDVI or Modified Normalize Difference Water Index (MNDWI algorithms, while the mono-window algorithm was used to retrieve the Land Surface Temperature (LST. Correlation analysis and Multi-Linear Regression (MLR model were applied to quantitatively analyse the effects of the urban parameters. From the study, it was found that the two urban parameters have significant effects on the LST of Kuala Lumpur City. The built-up areas have greater influence on the LST as compared to the green areas. The built-up areas tend to increase the LST while green areas especially the densely vegetated areas help to reduce the LST within an urban areas. Future studies should focus on improving existing urban climatic model by including other urban parameters.

Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

Science.gov (United States)

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

Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

Directory of Open Access Journals (Sweden)

L. Yu

2018-01-01

Full Text Available 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

Nanotechnological Advances in Catalytic Thin Films for Green Large-Area Surfaces

Directory of Open Access Journals (Sweden)

Suzan Biran Ay

2015-01-01

Full Text Available Large-area catalytic thin films offer great potential for green technology applications in order to save energy, combat pollution, and reduce global warming. These films, either embedded with nanoparticles, shaped with nanostructuring techniques, hybridized with other systems, or functionalized with bionanotechnological methods, can include many different surface properties including photocatalytic, antifouling, abrasion resistant and mechanically resistive, self-cleaning, antibacterial, hydrophobic, and oleophobic features. Thus, surface functionalization with such advanced structuring methods is of significance to increase the performance and wide usage of large-area thin film coatings specifically for environmental remediation. In this review, we focus on methods to increase the efficiency of catalytic reactions in thin film and hence improve the performance in relevant applications while eliminating high cost with the purpose of widespread usage. However, we also include the most recent hybrid architectures, which have potential to make a transformational change in surface applications as soon as high quality and large area production techniques are available. Hence, we present and discuss research studies regarding both organic and inorganic methods that are used to structure thin films that have potential for large-area and eco-friendly coatings.

Influence of Ecological Factors on Estimation of Impervious Surface Area Using Landsat 8 Imagery

Directory of Open Access Journals (Sweden)

Yuqiu Jia

2017-07-01

Full Text Available Estimation of impervious surface area is important to the study of urban environments and social development, but surface characteristics, as well as the temporal, spectral, and spatial resolutions of remote sensing images, influence the estimation accuracy. To investigate the effects of regional environmental characteristics on the estimation of impervious surface area, we divided China into seven sub-regions based on climate, soil type, feature complexity, and vegetation phenology: arid and semi-arid areas, Huang-Huai-Hai winter wheat production areas, typical temperate regions, the Pearl River Delta, the middle and lower reaches of the Yangtze River, typical tropical and subtropical regions, and the Qinghai Tibet Plateau. Impervious surface area was estimated from Landsat 8 images of five typical cities, including Yinchuan, Shijiazhuang, Shenyang, Ningbo, and Kunming. Using the linear spectral unmixing method, impervious and permeable surface areas were determined at the pixel-scale based on end-member proportions. We calculated the producer’s accuracy, user’s accuracy, and overall accuracy to assess the estimation accuracy, and compared the accuracies among images acquired from different seasons and locations. In tropical and subtropical regions, vegetation canopies can confound the identification of impervious surfaces and, thus, images acquired in winter, early spring, and autumn are most suitable; estimations in the Pearl River Delta, the middle and lower reaches of the Yangtze River are influenced by soil, vegetation phenology, vegetation canopy, and water, and images acquired in spring, summer, and autumn provide the best results; in typical temperate areas, images acquired from spring to autumn are most effective for estimations; in winter wheat-growing areas, images acquired throughout the year are suitable; and in arid and semi-arid areas, summer and early autumn, during which vegetation is abundant, are the optimal seasons for

Hand surface area estimation formula using 3D anthropometry.

Science.gov (United States)

Hsu, Yao-Wen; Yu, Chi-Yuang

2010-11-01

Hand surface area is an important reference in occupational hygiene and many other applications. This study derives a formula for the palm surface area (PSA) and hand surface area (HSA) based on three-dimensional (3D) scan data. Two-hundred and seventy subjects, 135 males and 135 females, were recruited for this study. The hand was measured using a high-resolution 3D hand scanner. Precision and accuracy of the scanner is within 0.67%. Both the PSA and HSA were computed using the triangular mesh summation method. A comparison between this study and previous textbook values (such as in the U.K. teaching text and Lund and Browder chart discussed in the article) was performed first to show that previous textbooks overestimated the PSA by 12.0% and HSA by 8.7% (for the male, PSA 8.5% and HSA 4.7%, and for the female, PSA 16.2% and HSA 13.4%). Six 1D measurements were then extracted semiautomatically for use as candidate estimators for the PSA and HSA estimation formula. Stepwise regressions on these six 1D measurements and variable dependency test were performed. Results show that a pair of measurements (hand length and hand breadth) were able to account for 96% of the HSA variance and up to 98% of the PSA variance. A test of the gender-specific formula indicated that gender is not a significant factor in either the PSA or HSA estimation.

Ambient pressure dried tetrapropoxysilane-based silica aerogels with high specific surface area

Science.gov (United States)

Parale, Vinayak G.; Han, Wooje; Jung, Hae-Noo-Ree; Lee, Kyu-Yeon; Park, Hyung-Ho

2018-01-01

In the present paper, we report the synthesis of tetrapropoxysilane (TPOS)-based silica aerogels with high surface area and large pore volume. The silica aerogels were prepared by a two-step sol-gel process followed by surface modification via a simple ambient pressure drying approach. In order to minimize drying shrinkage and obtain hydrophobic aerogels, the surface of the alcogels was modified using trichloromethylsilane as a silylating agent. The effect of the sol-gel compositional parameters on the polymerization of aerogels prepared by TPOS, one of the precursors belonging to the Si(OR)4 family, was reported for the first time. The oxalic acid and NH4OH concentrations were adjusted to achieve good-quality aerogels with high surface area, low density, and high transparency. Controlling the hydrolysis and condensation reactions of the TPOS precursor turned out to be the most important factor to determine the pore characteristics of the aerogel. Highly transparent aerogels with high specific surface area (938 m2/g) and low density (0.047 g/cm3) could be obtained using an optimized TPOS/MeOH molar ratio with appropriate concentrations of oxalic acid and NH4OH.

Characteristics of surface O{sub 3} over Qinghai Lake area in Northeast Tibetan Plateau, China

Energy Technology Data Exchange (ETDEWEB)

Shen, Zhenxing, E-mail: zxshen@mail.xjtu.edu.cn [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China); Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Cao, Junji [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhang, Leiming [Air Quality Research Division, Environment Canada, Toronto (Canada); Zhao, Zhuzi [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Dong, Jungang [School of Architecture, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Wang, Linqing [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China); Wang, Qiyuan; Li, Guohui; Liu, Suixin [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhang, Qian [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China)

2014-12-01

Surface O{sub 3} was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3200 m above sea level) in Qinghai Lake area (36°58′37″N, 99°53′56″E) in Northeast Tibetan Plateau, China. Daily average O{sub 3} ranged from 21.8 ppbv to 65.3 ppbv with an annual average of 41.0 ppbv. Seasonal average of O{sub 3} followed a decreasing order of summer > autumn > spring > winter. Diurnal variations of O{sub 3} showed low concentrations during daytime and high concentrations during late night and early morning. An intensive campaign was also conducted during Aug. 13–31, 2010 to investigate correlations between meteorological or chemical conditions and O{sub 3}. It was found that O{sub 3} was poorly correlated with solar radiation due to the insufficient NO{sub x} in the ambient air, thus limiting O{sub 3} formation under strong solar radiation. In contrast, high O{sub 3} levels always coincided with strong winds, suggesting that stratospheric O{sub 3} and long range transport might be the main sources of O{sub 3} in this rural area. Back-trajectory analysis supported this hypothesis and further indicated the transport of air masses from northwest, northeast and southeast directions. - Highlights: • Surface O{sub 3} was measured in Qinghai Lake area in Northeast Tibetan Plateau, China. • The O{sub 3} chemical formation was under a strong NOx-limited in Qinghai Lake areas. • Stratospheric O{sub 3} and transport might be the main sources of O{sub 3} in this area.

Growth of contact area between rough surfaces under normal stress

Science.gov (United States)

Stesky, R. M.; Hannan, S. S.

1987-05-01

The contact area between deforming rough surfaces in marble, alabaster, and quartz was measured from thin sections of surfaces bonded under load with low viscosity resin epoxy. The marble and alabaster samples had contact areas that increased with stress at an accelerating rate. This result suggests that the strength of the asperity contacts decreased progressively during the deformation, following some form of strain weakening relationship. This conclusion is supported by petrographic observation of the thin sections that indicate that much of the deformation was cataclastic, with minor twinning of calcite and kinking of gypsum. In the case of the quartz, the observed contact area was small and increased approximately linearly with normal stress. Only the irreversible cataclastic deformation was observed; however strain-induced birefringence and cracking of the epoxy, not observed with the other rocks, suggests that significant elastic deformation occurred, but recovered during unloading.

Reliable solution processed planar perovskite hybrid solar cells with large-area uniformity by chloroform soaking and spin rinsing induced surface precipitation

Directory of Open Access Journals (Sweden)

Yann-Cherng Chern

2015-08-01

Full Text Available A solvent soaking and rinsing method, in which the solvent was allowed to soak all over the surface followed by a spinning for solvent draining, was found to produce perovskite layers with high uniformity on a centimeter scale and with much improved reliability. Besides the enhanced crystallinity and surface morphology due to the rinsing induced surface precipitation that constrains the grain growth underneath in the precursor films, large-area uniformity with film thickness determined exclusively by the rotational speed of rinsing spinning for solvent draining was observed. With chloroform as rinsing solvent, highly uniform and mirror-like perovskite layers of area as large as 8 cm × 8 cm were produced and highly uniform planar perovskite solar cells with power conversion efficiency of 10.6 ± 0.2% as well as much prolonged lifetime were obtained. The high uniformity and reliability observed with this solvent soaking and rinsing method were ascribed to the low viscosity of chloroform as well as its feasibility of mixing with the solvent used in the precursor solution. Moreover, since the surface precipitation forms before the solvent draining, this solvent soaking and rinsing method may be adapted to spinless process and be compatible with large-area and continuous production. With the large-area uniformity and reliability for the resultant perovskite layers, this chloroform soaking and rinsing approach may thus be promising for the mass production and commercialization of large-area perovskite solar cells.

Study of measurement methods of ultrafine aerosols surface-area for characterizing occupational exposure

International Nuclear Information System (INIS)

Bau, S.

2008-12-01

This work aims at improving knowledge on ultrafine aerosols surface-area measurement. Indeed, the development of nano-technologies may lead to occupational exposure to airborne nano-structured particles, which involves a new prevention issue. There is currently no consensus concerning what parameter (mass, surface-area, number) should be measured. However, surface-area could be a relevant metric, since it leads to a satisfying correlation with biological effects when nano-structured particles are inhaled. Hence, an original theoretical work was performed to position the parameter of surface-area in relation to other aerosol characteristics. To investigate measurement techniques of nano-structured aerosols surface-area, the experimental facility CAIMAN (Characterization of Instruments for the Measurement of Aerosols of Nano-particles) was designed and built. Within CAIMAN, it is possible to produce nano-structured aerosols with varying and controlled properties (size, concentration, chemical nature, morphology, state-of-charge), stable and reproducible in time. The generated aerosols were used to experimentally characterize the response of the instruments in study (NSAM and AeroTrak 9000 TSI, LQ1-DC Matter Engineering). The response functions measured with monodisperse aerosols show a good agreement with the corresponding theoretical curves in a large size range, from 15 to 520 nm. Furthermore, hypotheses have been formulated to explain the reasonable biases observed when measuring poly-disperse aerosols. (author)

Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

Energy Technology Data Exchange (ETDEWEB)

Moenkkoenen, H. [WSP Finland Oy, Helsinki (Finland)

2012-04-15

In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

Models of bedrock surface and overburden thickness over Olkiluoto island and nearby sea area

International Nuclear Information System (INIS)

Moenkkoenen, H.

2012-04-01

In this report, a model of bedrock surface and a model of overburden thickness over the Olkiluoto Island and the nearby sea area are presented. Also in purpose to produce material for biosphere and radionuclide transport modelling, stratigraphy models of different sediment layers were created at two priority areas north and south of the Olkiluoto Island. The work concentrated on the collection and description of available data of bedrock surface and overburden thickness. Because the information on the bedrock surface and overburden is collected from different sources and is based on a number of types of data the quality and applicability of data sets varies. Consequently also the reliability in different parts of the models varies. Input data for the bedrock surface and overburden thickness models include 2928 single points and additional outcrops observations (611 polygons) in the modelled area. In addition, the input data include 173 seismic refraction lines (6534 points) and acousticseismic sounding lines (26655 points from which 13721 points are located in model area) in the Olkiluoto offshore area. The average elevation of bedrock surface in area is 2.1 metres above the sea level. The average thickness of overburden is 2.5 metres varying typically between 2 - 4 metres. Thickest overburden covers (approximately 16 metres) of terrestrial area are located at the western end of the Olkiluoto Island and in sea basin south of the island. (orig.)

Surface and bulk MHD instabilities due to insulator coating imperfections

International Nuclear Information System (INIS)

Xu Zengyu; Reed, C.B.; Pan Chuanjie

2002-01-01

Experiments were performed using copper electrodes inserted into the wall of a perfectly insulated duct to simulate insulator coating flaking or cracking. The results show that surface electric potential U and MHD pressure drop ΔP exhibit a non-monotonic behavior with increasing V 0 , while the magnetic field B 0 is held constant. Additional experiments were also performed keeping all external experimental conditions fixed while measuring the change of U, V 0 , B 0 , and ΔP with increasing time. It was found that while all external experimental conditions were kept constant, the system changed by itself and U, V 0 and ΔP exhibited a non-monotonic behavior with increasing time. The results seem contrary to the law of ΔP∝V 0 B 0 n , but are consistent with conservation of energy, which implies that the change is due to some inherent feature of the system, or possibly instabilities, which may occur due to insulator coating imperfections

Planar spatial correlations, anisotropy, and specific surface area of stationary random porous media

International Nuclear Information System (INIS)

Berryman, J.G.

1998-01-01

An earlier result of the author showed that an anisotropic spatial correlation function of a random porous medium could be used to compute the specific surface area when it is stationary as well as anisotropic by first performing a three-dimensional radial average and then taking the first derivative with respect to lag at the origin. This result generalized the earlier result for isotropic porous media of Debye et al. [J. Appl. Phys. 28, 679 (1957)]. The present article provides more detailed information about the use of spatial correlation functions for anisotropic porous media and in particular shows that, for stationary anisotropic media, the specific surface area can be related to the derivative of the two-dimensional radial average of the correlation function measured from cross sections taken through the anisotropic medium. The main concept is first illustrated using a simple pedagogical example for an anisotropic distribution of spherical voids. Then, a general derivation of formulas relating the derivative of the planar correlation functions to surface integrals is presented. When the surface normal is uniformly distributed (as is the case for any distribution of spherical voids), our formulas can be used to relate a specific surface area to easily measurable quantities from any single cross section. When the surface normal is not distributed uniformly (as would be the case for an oriented distribution of ellipsoidal voids), our results show how to obtain valid estimates of specific surface area by averaging measurements on three orthogonal cross sections. One important general observation for porous media is that the surface area from nearly flat cracks may be underestimated from measurements on orthogonal cross sections if any of the cross sections happen to lie in the plane of the cracks. This result is illustrated by taking the very small aspect ratio (penny-shaped crack) limit of an oblate spheroid, but holds for other types of flat surfaces as well

Electromagnetic surface waves for large-area RF plasma productions between large-area planar electrodes

International Nuclear Information System (INIS)

Nonaka, S.

1992-01-01

Recently, large-area plasma production has been tested by means of a 13.56 MHz radio-frequency (RF) discharge between a pair of large-area planar electrodes, approximately 0.5 m x 1.4 m, as one of the semiconductor technologies for fabrication of large-area amorphous silicon solar cells in the ''Sunshine Project'' of the Agency of Industrial Science and Technology in Japan. We also confirmed long plasma production between a pair of long electrodes. In this paper, normal electromagnetic (EM) waves propagating in a region between a planar waveguide with one plasma and two dielectric layers are analyzed in order to study the feasibility of large-area plasma productions by EM wave-discharges between a pair of large-area RF electrodes larger than the half-wavelength of RF wave. In conclusion, plasmas higher than an electron plasma frequency will be produced by an odd TMoo surface mode. (author) 4 refs., 3 figs

A new type of surface acoustic waves in solids due to nonlinear elasticity

International Nuclear Information System (INIS)

Mozhaev, V.G.

1988-12-01

It is shown that in nonlinear elastic semi-infinite medium possessing a property of self focusing of shear waves, besides bulk non-linear shear waves, new surface acoustic waves exist, localization of which near the boundary is entirely due to nonlinear effects. (author). 8 refs

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

International Nuclear Information System (INIS)

Papelis, Charalambos; Um, Wooyong; Russel, Charles E.; Chapman, Jenny B.

2003-01-01

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. 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

A sampling scheme intended for tandem measurements of sodium transport and microvillous surface area in the coprodaeal epithelium of hens on high- and low-salt diets.

Science.gov (United States)

Mayhew, T M; Dantzer, V; Elbrønd, V S; Skadhauge, E

1990-12-01

A tissue sampling protocol for combined morphometric and physiological studies on the mucosa of the avian coprodaeum is presented. The morphometric goal is to estimate the surface area due to microvilli at the epithelial cell apex and the proposed scheme is illustrated using material from three White Plymouth Rock hens. The scheme is designed to satisfy sampling requirements for the unbiased estimation of surface areas by vertical sectioning coupled with cycloid test lines and it incorporates a number of useful internal checks. It relies on multi-level sampling with four levels of stereological estimation. At Level I, macroscopic estimates of coprodaeal volume are obtained. Light microscopy is employed at Level II to calculate epithelial volume density. Levels III and IV require low and high power electron microscopy to estimate the surface density of the epithelial apical border and the amplification factor due to microvilli. Worked examples of the calculation steps are provided.

Analysis and Application of River Surface Line in Hilly Area based on Hec-ras Model

Directory of Open Access Journals (Sweden)

Yang Congshan

2017-01-01

Full Text Available For example—Cixian Fuyang River Regulation Project. Due to the character that Fuyang River is located in hilly areas of Cixian, we use the Hex-ras software to calculate the status of the river water surface line for the goal of determining the final treatment plan. We maintain the present situation of the river channel design as principle, select the most appropriate pushed water level and roughnessas the basic, and we combine the classification calculation of crossing structures of backwater and the encryption calculation section to get the more accurate result. We compare the water level elevation and the calculation of cross strait, analyze the design parameters, calculate repeated the water line section, analyze the rationality of the design plan, and then finally determine the applicability of Hex-rac software in the large continuous variation of cross section of embankment of river river surface line.

Estimation of surface area concentration of workplace incidental nanoparticles based on number and mass concentrations

Science.gov (United States)

Park, J. Y.; Ramachandran, G.; Raynor, P. C.; Kim, S. W.

2011-10-01

Surface area was estimated by three different methods using number and/or mass concentrations obtained from either two or three instruments that are commonly used in the field. The estimated surface area concentrations were compared with reference surface area concentrations (SAREF) calculated from the particle size distributions obtained from a scanning mobility particle sizer and an optical particle counter (OPC). The first estimation method (SAPSD) used particle size distribution measured by a condensation particle counter (CPC) and an OPC. The second method (SAINV1) used an inversion routine based on PM1.0, PM2.5, and number concentrations to reconstruct assumed lognormal size distributions by minimizing the difference between measurements and calculated values. The third method (SAINV2) utilized a simpler inversion method that used PM1.0 and number concentrations to construct a lognormal size distribution with an assumed value of geometric standard deviation. All estimated surface area concentrations were calculated from the reconstructed size distributions. These methods were evaluated using particle measurements obtained in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory. SAPSD was 0.7-1.8 times higher and SAINV1 and SAINV2 were 2.2-8 times higher than SAREF in the restaurant and diesel engine laboratory. In the die casting facility, all estimated surface area concentrations were lower than SAREF. However, the estimated surface area concentration using all three methods had qualitatively similar exposure trends and rankings to those using SAREF within a workplace. This study suggests that surface area concentration estimation based on particle size distribution (SAPSD) is a more accurate and convenient method to estimate surface area concentrations than estimation methods using inversion routines and may be feasible to use for classifying exposure groups and identifying exposure trends.

Estimation of surface area concentration of workplace incidental nanoparticles based on number and mass concentrations

International Nuclear Information System (INIS)

Park, J. Y.; Ramachandran, G.; Raynor, P. C.; Kim, S. W.

2011-01-01

Surface area was estimated by three different methods using number and/or mass concentrations obtained from either two or three instruments that are commonly used in the field. The estimated surface area concentrations were compared with reference surface area concentrations (SA REF ) calculated from the particle size distributions obtained from a scanning mobility particle sizer and an optical particle counter (OPC). The first estimation method (SA PSD ) used particle size distribution measured by a condensation particle counter (CPC) and an OPC. The second method (SA INV1 ) used an inversion routine based on PM1.0, PM2.5, and number concentrations to reconstruct assumed lognormal size distributions by minimizing the difference between measurements and calculated values. The third method (SA INV2 ) utilized a simpler inversion method that used PM1.0 and number concentrations to construct a lognormal size distribution with an assumed value of geometric standard deviation. All estimated surface area concentrations were calculated from the reconstructed size distributions. These methods were evaluated using particle measurements obtained in a restaurant, an aluminum die-casting factory, and a diesel engine laboratory. SA PSD was 0.7–1.8 times higher and SA INV1 and SA INV2 were 2.2–8 times higher than SA REF in the restaurant and diesel engine laboratory. In the die casting facility, all estimated surface area concentrations were lower than SA REF . However, the estimated surface area concentration using all three methods had qualitatively similar exposure trends and rankings to those using SA REF within a workplace. This study suggests that surface area concentration estimation based on particle size distribution (SA PSD ) is a more accurate and convenient method to estimate surface area concentrations than estimation methods using inversion routines and may be feasible to use for classifying exposure groups and identifying exposure trends.

Description of surface systems. Preliminary site description Simpevarp sub area - Version 1.2

Energy Technology Data Exchange (ETDEWEB)

Lindborg, Tobias [ed.

2005-03-01

Swedish Nuclear Fuel and Waste Management Co is currently conducting site characterisation in the Simpevarp area. The area is divided into two subareas, the Simpevarp and the Laxemar subarea. The two subareas are surrounded by a common regional model area, the Simpevarp area. This report describes both the regional area and the subareas. This report is an interim version (model version 1.2) of the description of the surface systems at the Simpevarp area, and should be seen as a background report to the site description of the Simpevarp area, version 1.2, SKB-R--05-08. The basis for this description is quality-assured field data available in the SKB SICADA and GIS databases, together with generic data from the literature. The Surface system, here defined as everything above the bedrock, comprises a number of separate disciplines (e.g. hydrology, geology, topography, oceanography and ecology). Each discipline has developed descriptions and models for a number of properties that together represent the site description. The current methodology for developing the surface system description and the integration to ecosystem models is documented in a methodology strategy report SKB-R--03-06. The procedures and guidelines given in that report were followed in this report. Compared with version 1.1 of the surface system description SKB-R--04-25, this report presents considerable additional features, especially in the ecosystem description (Chapter 4) and in the description of the surface hydrology (Section 3.4). A first attempt has also been made to connect the flow of matter (carbon) between the different ecosystems into an overall ecosystem model at a landscape level. A summarised version of this report is also presented in SKB-R--05-08 together with geological-, hydrogeological-, transport properties-, thermal properties-, rock mechanics- and hydrogeochemical descriptions.

Description of surface systems. Preliminary site description Simpevarp sub area - Version 1.2

International Nuclear Information System (INIS)

Lindborg, Tobias

2005-03-01

Swedish Nuclear Fuel and Waste Management Co is currently conducting site characterisation in the Simpevarp area. The area is divided into two subareas, the Simpevarp and the Laxemar subarea. The two subareas are surrounded by a common regional model area, the Simpevarp area. This report describes both the regional area and the subareas. This report is an interim version (model version 1.2) of the description of the surface systems at the Simpevarp area, and should be seen as a background report to the site description of the Simpevarp area, version 1.2, SKB-R--05-08. The basis for this description is quality-assured field data available in the SKB SICADA and GIS databases, together with generic data from the literature. The Surface system, here defined as everything above the bedrock, comprises a number of separate disciplines (e.g. hydrology, geology, topography, oceanography and ecology). Each discipline has developed descriptions and models for a number of properties that together represent the site description. The current methodology for developing the surface system description and the integration to ecosystem models is documented in a methodology strategy report SKB-R--03-06. The procedures and guidelines given in that report were followed in this report. Compared with version 1.1 of the surface system description SKB-R--04-25, this report presents considerable additional features, especially in the ecosystem description (Chapter 4) and in the description of the surface hydrology (Section 3.4). A first attempt has also been made to connect the flow of matter (carbon) between the different ecosystems into an overall ecosystem model at a landscape level. A summarised version of this report is also presented in SKB-R--05-08 together with geological-, hydrogeological-, transport properties-, thermal properties-, rock mechanics- and hydrogeochemical descriptions

Peanut Shell-Derived Carbon Solid Acid with Large Surface Area and Its Application for the Catalytic Hydrolysis of Cyclohexyl Acetate

Directory of Open Access Journals (Sweden)

Wei Xue

2016-10-01

Full Text Available A carbon solid acid with large surface area (CSALA was prepared by partial carbonization of H3PO4 pre-treated peanut shells followed by sulfonation with concentrated H2SO4. The structure and acidity of CSALA were characterized by N2 adsorption–desorption, scanning electron microscopy (SEM, X-ray powder diffraction (XRD, 13C cross polarization (CP/magic angle spinning (MAS nuclear magnetic resonance (NMR, X-ray photoelectron spectroscopy (XPS, Fourier transform-infrared spectroscopy (FT-IR, titration, and elemental analysis. The results demonstrated that the CSALA was an amorphous carbon material with a surface area of 387.4 m2/g. SO3H groups formed on the surface with a density of 0.46 mmol/g, with 1.11 mmol/g of COOH and 0.39 mmol/g of phenolic OH. Densities of the latter two groups were notably greater than those observed on a carbon solid acid (CSA with a surface area of 10.1 m2/g. The CSALA catalyst showed better performance than the CSA for the hydrolysis of cyclohexyl acetate to cyclohexanol. Under optimal reaction conditions, cyclohexyl acetate conversion was 86.6% with 97.3% selectivity for cyclohexanol, while the results were 25.0% and 99.4%, respectively, catalyzed by CSA. The high activity of the CSALA could be attributed to its high density of COOH and large surface area. Moreover, the CSALA showed good reusability. Its catalytic activity decreased slightly during the first two cycles due to the leaching of polycyclic aromatic hydrocarbon-containing SO3H groups, and then remained constant during following uses.

Heavy metal contamination in surface runoff sediments of the urban area of Vilnius, Lithuania

Directory of Open Access Journals (Sweden)

Gytautas Ignatavičius

2017-02-01

Full Text Available Surface runoff from urbanized territories carries a wide range of pollutants. Sediments in untreated runoff from direct discharge stormwater systems significantly contribute to urban waterway pollution. In this study, heavy metal (Pb, Zn, Cu, Cr, Ba, As and Fe contamination in surface runoff sediments of the urban area of the city of Vilnius was investigated. The surface runoff sediment samples were collected from seven dischargers with the highest volume rate of water flow and concentrations of suspended solids. The geospatial analysis of the distribution of heavy metals shows that there are several active pollution sources supplying the dischargers with contaminated sediments. Most of these areas are located in the central part of the city and in old town with intense traffic. Principal components analysis and t-test results clearly depicted the significantly different chemical compositions of winter and autumn surface sediment samples. The sampling approach and assessment of results provide a useful tool to examine the contamination that is generated in urban areas, distinguish pollution sources and give a better understanding of the importance of permeable surfaces and green areas.

Transport and retention of phosphorus in surface water in an urban slum area

Science.gov (United States)

Nyenje, P. M.; Meijer, L. M. G.; Foppen, J. W.; Kulabako, R.; Uhlenbrook, S.

2013-08-01

The transport of excessive phosphorus (P) discharged from unsewered informal settlements (slums) due to poor on-site sanitation is largely unknown. Hence, we investigated the processes governing P transport in a 28 km2 slum-dominated catchment in Kampala, Uganda. During high runoff events and a period of base flow, we collected hourly water samples (over 24 h) from a primary channel draining the catchment and from a small size tertiary channel draining one of the contributing slum areas (0.5 km2). Samples were analyzed for orthophosphate (PO4-P), particulate P (PP), total P (TP) and selected hydro-chemical parameters. Channel bed and suspended sediments were collected to determine their sorption potential, geo-available metals and dominant P forms. We found that P inputs in the catchment originated mainly from domestic wastewater as evidenced by high concentrations of Cl (36-144 mg L-1), HCO3 and other cations in the channels. Most P discharged during low flow conditions was particulate implying that much of it was retained in bed sediments. Retained P was mostly bound to Ca and Fe/Al oxides. Hence, we inferred that mineral precipitation and adsorption to Ca-minerals were the dominant P retention processes. Bed sediments were P-saturated and showed a tendency to release P to discharging waters. P released was likely due to Ca-bound P because of the strong correlation between Ca and total P in sediments (r2 = 0.9). High flows exhibited a strong flush of PP and SS implying that part of P retained was frequently flushed out of the catchment by surface erosion and resuspension of bed sediment. Our findings suggest that P accumulated in the channel bed during low flows and then was slowly released into surface water. Hence, it will likely take some time, even with improved wastewater management practices, before P loads to downstream areas can be significantly reduced.

[Dehydration due to "mouth broken"].

Science.gov (United States)

Meijler, D P M; van Mossevelde, P W J; van Beek, R H T

2012-09-01

Two children were admitted to a medical centre due to dehydration after an oral injury and the extraction of a tooth. One child complained of "mouth broken". Dehydration is the most common water-electrolyte imbalance in children. Babies and young children are prone to dehydration due to their relatively large body surface area, the high percentage extracellular fluid, and the limited ability of the kidneys to conserve water. After the removal ofa tooth, after an oral trauma or in case of oral discomfort, a child is at greater risk of dehydration by reduced fluid and food intake due to oral pain and/or discomfort and anxiety to drink. In those cases, extra attention needs to be devoted to the intake of fluids.

Sintering of uranium oxide of high specific surface area

International Nuclear Information System (INIS)

Bel, Alain; Francois, Bernard; Delmas, Roger; Caillat, Roger

1959-01-01

The extent to which a uranium oxide powder deriving from ammonium uranate or uranium peroxide lends itself to the sintering process depends largely on its specific surface area. When this is greater than 5 m 2 / g there is an optimum temperature for sintering in hydrogen. This temperature becomes less as the specific area of the powder is greater. Reprint of a paper published in Comptes rendus des seances de l'Academie des Sciences, t. 249, p. 1045-1047, sitting of 21 September 1959 [fr

Interdependence between body surface area and ultraviolet B dose in vitamin D production

DEFF Research Database (Denmark)

Bogh, M K B; Schmedes, Anne; Philipsen, P A

2011-01-01

Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25-hydroxyvitamin-D(3) [25(OH)D], but the relationship to body surface area and UVB dose needs investigation.......Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25-hydroxyvitamin-D(3) [25(OH)D], but the relationship to body surface area and UVB dose needs investigation....

30 CFR 903.761 - Areas designated unsuitable for surface coal mining by act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by act of Congress. 903.761 Section 903.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, applies to surface coal mining...

Assessment of anthropogenic inputs in the surface waters of the southern coastal area of Sfax during spring (Tunisia, Southern Mediterranean Sea).

Science.gov (United States)

Drira, Zaher; Kmiha-Megdiche, Salma; Sahnoun, Houda; Hammami, Ahmed; Allouche, Noureddine; Tedetti, Marc; Ayadi, Habib

2016-03-15

The coastal marine area of Sfax (Tunisia), which is well-known for its high productivity and fisheries, is also subjected to anthropogenic inputs from diverse industrial, urban and agriculture activities. We investigated the spatial distribution of physical, chemical and biogeochemical parameters in the surface waters of the southern coastal area of Sfax. Pertinent tracers of anthropogenic inputs were identified. Twenty stations were sampled during March 2013 in the vicinity of the coastal areas reserved for waste discharge. Phosphogypsum wastes dumped close to the beaches were the main source of PO4(3-), Cl(-) and SO4(2-) in seawater. The high content in total polyphenolic compounds was due to the olive oil treatment waste water released from margins. These inorganic and organic inputs in the surface waters were associated with elevated COD. The BOD5/COD (3) ratios highlighted a chemical pollution with organic load of a low biodegradability. Copyright © 2016 Elsevier Ltd. All rights reserved.

30 CFR 942.761 - Areas designated unsuitable for surface coal mining by act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by act of Congress. 942.761 Section 942.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining...

30 CFR 910.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by Act of Congress. 910.761 Section 910.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining...

30 CFR 937.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

Science.gov (United States)

2010-07-01

... mining by Act of Congress. 937.761 Section 937.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... WITHIN EACH STATE OREGON § 937.761 Areas designated unsuitable for surface coal mining by Act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and...

30 CFR 921.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by Act of Congress. 921.761 Section 921.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining...

30 CFR 912.761 - Areas designated unsuitable for surface coal mining by act of Congress.

Science.gov (United States)

2010-07-01

... mining by act of Congress. 912.761 Section 912.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... WITHIN EACH STATE IDAHO § 912.761 Areas designated unsuitable for surface coal mining by act of Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining and...

30 CFR 947.761 - Areas designated unsuitable for surface coal mining by act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by act of Congress. 947.761 Section 947.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining...

30 CFR 939.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by Act of Congress. 939.761 Section 939.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining...

30 CFR 941.761 - Areas designated unsuitable for surface coal mining by act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by act of Congress. 941.761 Section 941.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining...

30 CFR 922.761 - Areas designated unsuitable for surface coal mining by act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by act of Congress. 922.761 Section 922.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining...

30 CFR 905.761 - Areas designated unsuitable for surface coal mining by act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by act of Congress. 905.761 Section 905.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated by Act of Congress, shall apply to surface coal mining...

Monitoring of Surface Subsidence of the Mining Area Based on Sbas

Science.gov (United States)

Zhu, Y.; Zhou, S.; Zang, D.; Lu, T.

2018-05-01

This paper has collected 7 scenes of L band PALSAR sensor radar data of a mine in FengCheng city, jiangxi province, using the Small-baseline Subset (SBAS) method to invert the surface subsidence of the mine. Baselines of interference less than 800m has been chosen to constitute short baseline differential interference atlas, using pixels whose average coherent coefficient was larger than or equal to 0.3 as like high coherent point target, using singular value decomposition (SVD) method to calculate deformation phase sequence based on these high coherent points, and the accumulation of settlements of study area of different period had been obtained, so as to reflect the ground surface settlement evolution of the settlement of the area. The results of the study has showed that: SBAS technology has overcome coherent problem of the traditionality D-InSAR technique, continuous deformation field of surface mining in time dimension of time could been obtained, characteristics of ground surface settlement of mining subsidence in different period has been displayed, so to improve the accuracy and reliability of the monitoring results.

Radiative surface temperatures of the burned and unburned areas in a tallgrass prairie

International Nuclear Information System (INIS)

Asrar, G.; Harris, T.R.; Lapitan, R.L.; Cooper, D.I.

1988-01-01

This study was conducted in a natural tallgrass prairie area in the Flint Hills of Kansas. Our objective was to evaluate the surface radiative temperatures of burned and unburned treatments of the grassland as a means of delineating the areas covered by each treatment. Burning is used to remove the senescent vegetation resulting from the previous year's growth. Surface temperatures were obtained in situ and by an airborne scanner. Burned and unburned grass canopies had distinctly different diurnal surface radiative temperatures. Measurements of surface energy balance components revealed a difference in partitioning of the available energy between the two canopies, which resulted in the difference in their measured surface temperatures. The magnitude of this difference is dependent on the time of measurements and topographic conditions. (author)

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

Science.gov (United States)

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

Surface water and groundwater interaction in selected areas of Indus basin

International Nuclear Information System (INIS)

Akram, W.; Ahmad, M.; Tariq, J.A.; Latif, Z.; Malik, M.R.

2011-08-01

Isotope hydrological investigations were carried out in Marala-Khanki Area of Punjab for elucidating various aspects of surface water and groundwater interaction. Groundwater samples were collected on seasonal basis (low and high river discharge periods) while surface water (Chenab River) samples were collected more frequently (weekly or monthly basis). Isotopic data suggested that there is no significant contribution of surface water to groundwater recharge in Marala-Khanki Area and rain is the prevailing source of groundwater recharge. The data further revealed that isotopic values of Tarbala lake are higher than those of main lake. Indus river meaning that there is significant contribution of base flow in this pocket. Isotopic data of Indus river showed an increase at Tunsa as compared to Chashma in flow period indicating the high contribution of base flow at this point in time. Stable isotopes were successfully used to quantify the base flow contribution. (author)

Spatiotemporal variability of saturation excess surface runoff in flat fields due to interactions with meso- and microtopography

NARCIS (Netherlands)

Appels, W.M.; Noij, I.G.A.M.; Massop, H.T.L.

2013-01-01

Surface runoff is the fastest route from field to stream and the main transport route for sediment and adsorbed contaminants, and as such an important cause of surface water contamination in agricultural areas. The goals of the study were to explain differences in measured surface runoff volumes and

Comparison of surface area changes during sulfation of sodium bicarbonate in a simulated flue gas with and without NO

Energy Technology Data Exchange (ETDEWEB)

Weil, A.E.; Keener, T.C.; Khang, S.J. [University of Cincinnati, Cincinnati, OH (United States). Department of Civil and Environmental Engineering

1994-12-31

Sodium bicarbonate has been identified as one of the most efficient reagents for flue gas desulfurization. Sodium bicarbonate has been demonstrated both in bench scale and large scale applications by a number of researchers globally. Scattered reporting of plume discolouration during demonstrations of sodium bicarbonate injection have been attributed to the formation of the reddish-brown gas NO{sub 2}. The purpose of this study was to compare the surface area changes of sodium bicarbonate during flue gas desulfurization as it relates to the formation of NO{sub 2} The results of this study have indicated an anomolous behaviour with respect to previously published data for non reactive gas environments. Notably it was shown that flue gas with NO lowered the surface area, most likely due to the formation of a low melting eutectic of sodium nitrate and sulphate. Nitrogen uptake was found to coincide with water evolution from decomposition. The results of this study more clearly define, on the microstructural level, the sulphur uptake mode. A unique laboratory differential fixed bed reactor was designed for this study. The setup included a quick quench zone to quench the reactions for data acquisition. BET surface area, IR elemental analysis, XRD crystallographic identification and SEM imaging were used to characterize microstructural mechanisms and to confirm reaction paths. 4 refs., 3 figs., 2 tabs.

Surface structural damage study in cortical bone due to medical drilling.

Science.gov (United States)

Tavera R, Cesar G; De la Torre-I, Manuel H; Flores-M, Jorge M; Hernandez M, Ma Del Socorro; Mendoza-Santoyo, Fernando; Briones-R, Manuel de J; Sanchez-P, Jorge

2017-05-01

A bone's fracture could be produced by an excessive, repetitive, or sudden load. A regular medical practice to heal it is to fix it in two possible ways: external immobilization, using a ferule, or an internal fixation, using a prosthetic device commonly attached to the bone by means of surgical screws. The bone's volume loss due to this drilling modifies its structure either in the presence or absence of a fracture. To observe the bone's surface behavior caused by the drilling effects, a digital holographic interferometer is used to analyze the displacement surface's variations in nonfractured post-mortem porcine femoral bones. Several nondrilled post-mortem bones are compressed and compared to a set of post-mortem bones with a different number of cortical drillings. During each compression test, a series of digital interferometric holograms were recorded using a high-speed CMOS camera. The results are presented as pseudo 3D mesh displacement maps for comparisons in the physiological range of load (30 and 50 lbs) and beyond (100, 200, and 400 lbs). The high resolution of the optical phase gives a better understanding about the bone's microstructural modifications. Finally, a relationship between compression load and bone volume loss due to the drilling was observed. The results prove that digital holographic interferometry is a viable technique to study the conditions that avoid the surgical screw from loosening in medical procedures of this kind.

Surface area and volume determination of subgingival calculus using laser fluorescence.

Science.gov (United States)

Shakibaie, Fardad; Walsh, Laurence J

2014-03-01

Visible red (655 nm) laser fluorescence (LF) devices are currently used for identifying deposits of subgingival calculus on the root surfaces of teeth during dental examination and treatment; however, it is not known how the fluorescence readings produced by commercially available LF systems correlate to the nature of the deposits. This laboratory study explored the correlation between LF digital readings and the surface area and volume of subgingival calculus deposits on teeth. A collection of 30 extracted human posterior teeth with various levels of subgingival deposits of calculus across 240 sites were used in a clinical simulation, with silicone impression material used to replicate periodontal soft tissues. The teeth were scored by two examiners by using three commercial LF systems (DIAGNOdent, DIAGNOdent Pen and KEY3). The silicone was removed, and the teeth were removed for photography at × 20 magnification under white or ultraviolet light. The surface area, thickness, and volume were calculated, and both linear least squares regression and nonlinear (Spearman's rank method) correlation coefficients were determined. Visible red LF digital readings showed better correlation to calculus volume than to surface area. Overall, the best performance was found for the KEY3 system (Spearman coefficient 0.59), compared to the Classic DIAGNOdent (0.56) and the DIAGNOdent Pen (0.49). These results indicate that while visible red LF systems vary somewhat in performance, their LF readings provide a useful estimation of the volume of subgingival calculus deposits present on teeth.

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

Science.gov (United States)

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.

A Three-Dimensional Enormous Surface Area Aluminum Microneedle Array with Nanoporous Structure

Directory of Open Access Journals (Sweden)

Po Chun Chen

2013-01-01

Full Text Available We proposed fabricating an aluminum microneedle array with a nanochannel structure on the surface by combining micromachining, electrolyte polishing, and anodization methods. The microneedle array provides a three-dimensional (3D structure that possesses several hundred times more surface area than a traditional nanochannel template. Therefore, the microneedle array can potentially be used in many technology applications. This 3D microneedle array device can not only be used for painless injection or extraction, but also for storage, highly sensitive detection, drug delivery, and microelectrodes. From the calculation we made, the microneedle array not only increases surface area, but also enlarges the capacity of the device. Therefore, the microneedle array can further be used on many detecting, storing, or drug delivering applications.

Investigation on large-area fabrication of vivid shark skin with superior surface functions

Science.gov (United States)

Chen, Huawei; Zhang, Xin; Ma, Lingxi; Che, Da; Zhang, Deyuan; Sudarshan, T. S.

2014-10-01

Shark skin has attracted worldwide attention because of its superior drag reduction, antifouling performance induced from its unique surface morphology. Although the vivid shark skin has been fabricated by a bio-replicated micro-imprinting approach in previous studies and superior drag reduction effect has been validated in water tunnel, continuous large-area fabrication is still an obstacle to wide apply. In this paper, one novel bio-replication coating technology is proposed for large-area transfer of shark skin based on rapid UV curable paint. Apart from design of coating system, bio-replication accuracy of surface morphology was validated about 97% by comparison between shark skin template and coating surface morphology. Finally, the drag reduction and anti-fouling function of coating surface were tested in water tunnel and open algae pond respectively. Drag reduction rate of coating surface was validated about 12% higher and anti-fouling was proved to about hundred times ameliorate, all of which are more excellent than simple 2D riblet surface.

Nitrogen-doped ordered mesoporous carbon with a high surface area, synthesized through organic-inorganic coassembly, and its application in supercapacitors.

Science.gov (United States)

Song, Yanfang; Li, Li; Wang, Yonggang; Wang, Congxiao; Guo, Zaipin; Xia, Yongyao

2014-07-21

A new nitrogen-doped ordered mesoporous carbon (N-doped OMC) is synthesized by using an organic-inorganic coassembly method, in which resol is used as the carbon precursor, dicyandiamide as the nitrogen precursor, silicate oligomers as the inorganic precursors, and F127 as the soft template. The N-doped OMC possesses a surface area as high as 1374 m(2)  g(-1) and a large pore size of 7.4 nm. As an electrode material for supercapacitors, the obtained carbon exhibits excellent cycling stability and delivers a reversible specific capacitance as high as 308 F g(-1) in 1 mol L(-1) H(2)SO(4) aqueous electrolyte, of which 58 % of the capacity is due to pseudo-capacitance. The large specific capacitance is attributed to proper pore size distributions, large surface area, and high nitrogen content. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High Surface Area of Porous Silicon Drives Desorption of Intact Molecules

Science.gov (United States)

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

Large Area Diamond Tribological Surfaces with Negligible Wear in Extreme Environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In Phase I we propose to demonstrate the processing of very large area diamond sliding bearings and tribological surfaces. The bearings and surfaces will experience...

Accurate measurement of surface areas of anatomical structures by computer-assisted triangulation of computed tomography images

Energy Technology Data Exchange (ETDEWEB)

Allardice, J.T.; Jacomb-Hood, J.; Abulafi, A.M.; Williams, N.S. (Royal London Hospital (United Kingdom)); Cookson, J.; Dykes, E.; Holman, J. (London Hospital Medical College (United Kingdom))

1993-05-01

There is a need for accurate surface area measurement of internal anatomical structures in order to define light dosimetry in adjunctive intraoperative photodynamic therapy (AIOPDT). The authors investigated whether computer-assisted triangulation of serial sections generated by computed tomography (CT) scanning can give an accurate assessment of the surface area of the walls of the true pelvis after anterior resection and before colorectal anastomosis. They show that the technique of paper density tessellation is an acceptable method of measuring the surface areas of phantom objects, with a maximum error of 0.5%, and is used as the gold standard. Computer-assisted triangulation of CT images of standard geometric objects and accurately-constructed pelvic phantoms gives a surface area assessment with a maximum error of 2.5% compared with the gold standard. The CT images of 20 patients' pelves have been analysed by computer-assisted triangulation and this shows the surface area of the walls varies from 143 cm[sup 2] to 392 cm[sup 2]. (Author).

A Stream Tilling Approach to Surface Area Estimation for Large Scale Spatial Data in a Shared Memory System

Directory of Open Access Journals (Sweden)

Liu Jiping

2017-12-01

Full Text Available Surface area estimation is a widely used tool for resource evaluation in the physical world. When processing large scale spatial data, the input/output (I/O can easily become the bottleneck in parallelizing the algorithm due to the limited physical memory resources and the very slow disk transfer rate. In this paper, we proposed a stream tilling approach to surface area estimation that first decomposed a spatial data set into tiles with topological expansions. With these tiles, the one-to-one mapping relationship between the input and the computing process was broken. Then, we realized a streaming framework towards the scheduling of the I/O processes and computing units. Herein, each computing unit encapsulated a same copy of the estimation algorithm, and multiple asynchronous computing units could work individually in parallel. Finally, the performed experiment demonstrated that our stream tilling estimation can efficiently alleviate the heavy pressures from the I/O-bound work, and the measured speedup after being optimized have greatly outperformed the directly parallel versions in shared memory systems with multi-core processors.

Experimental study of microstructure changes due to low cycle fatigue of a steel nanocrystallised by Surface Mechanical Attrition Treatment (SMAT)

Energy Technology Data Exchange (ETDEWEB)

Sun, Z. [ICD, P2MN, LASMIS, University of Technology of Troyes, UMR 6281, CNRS, Troyes (France); Retraint, D., E-mail: delphine.retraint@utt.fr [ICD, P2MN, LASMIS, University of Technology of Troyes, UMR 6281, CNRS, Troyes (France); Baudin, T.; Helbert, A.L.; Brisset, F. [ICMMO, Univ Paris-Sud, Université Paris-Saclay, UMR CNRS 8182, 91405 Orsay Cedex (France); Chemkhi, M.; Zhou, J. [ICD, P2MN, LASMIS, University of Technology of Troyes, UMR 6281, CNRS, Troyes (France); Kanouté, P. [ICD, P2MN, LASMIS, University of Technology of Troyes, UMR 6281, CNRS, Troyes (France); ONERA, The French Aerospace Lab, 29 avenue de la Division Leclerc, 92322 Chatillon Cedex (France)

2017-02-15

Electron Backscatter Diffraction technique is used to characterize the microstructure of 316L steel generated by Surface Mechanical Attrition Treatment (SMAT) before and after low cycle fatigue tests. A grain size gradient is generated from the top surface to the interior of the samples after SMAT so that three main regions can be distinguished below the treated surface: (i) the ultra-fine grain area within 5 μm under the top surface with preferably oriented grains, (ii) the intermediate area where the original grains are partially transformed, and (iii) the edge periphery area where the original grains are just mechanically deformed with the presence of plastic slips. Fatigue tests show that cyclic loading does not change the grain orientation spread and does not activate any plastic slip in the ultra-fine grain top surface area induced by SMAT. On the opposite, in the plastically SMAT affected region including the intermediate area and the edge periphery area, new slip systems are activated by low cycle fatigue while the grain orientation spread is increased. These results represent a first very interesting step towards the characterization and understanding of mechanical mechanisms involved during the fatigue of a grain size gradient material. - Highlights: •LCF tests are carried out on specimens processed by SMAT. •EBSD is used to investigate microstructural changes induced by LCF. •A grain size gradient is generated by SMAT from surface to the bulk of the fatigue samples. •New slip systems are activated by LCF and GOS is increased in plastically deformed region. •However, these phenomena are not observed in the top surface ultra-fine grain area.

Experimental study of microstructure changes due to low cycle fatigue of a steel nanocrystallised by Surface Mechanical Attrition Treatment (SMAT)

International Nuclear Information System (INIS)

Sun, Z.; Retraint, D.; Baudin, T.; Helbert, A.L.; Brisset, F.; Chemkhi, M.; Zhou, J.; Kanouté, P.

2017-01-01

Electron Backscatter Diffraction technique is used to characterize the microstructure of 316L steel generated by Surface Mechanical Attrition Treatment (SMAT) before and after low cycle fatigue tests. A grain size gradient is generated from the top surface to the interior of the samples after SMAT so that three main regions can be distinguished below the treated surface: (i) the ultra-fine grain area within 5 μm under the top surface with preferably oriented grains, (ii) the intermediate area where the original grains are partially transformed, and (iii) the edge periphery area where the original grains are just mechanically deformed with the presence of plastic slips. Fatigue tests show that cyclic loading does not change the grain orientation spread and does not activate any plastic slip in the ultra-fine grain top surface area induced by SMAT. On the opposite, in the plastically SMAT affected region including the intermediate area and the edge periphery area, new slip systems are activated by low cycle fatigue while the grain orientation spread is increased. These results represent a first very interesting step towards the characterization and understanding of mechanical mechanisms involved during the fatigue of a grain size gradient material. - Highlights: •LCF tests are carried out on specimens processed by SMAT. •EBSD is used to investigate microstructural changes induced by LCF. •A grain size gradient is generated by SMAT from surface to the bulk of the fatigue samples. •New slip systems are activated by LCF and GOS is increased in plastically deformed region. •However, these phenomena are not observed in the top surface ultra-fine grain area.

Escaping the correction for body surface area when calculating glomerular filtration rate in children

International Nuclear Information System (INIS)

Piepsz, Amy; Tondeur, Marianne; Ham, Hamphrey

2008-01-01

51 Cr ethylene diamine tetraacetic acid ( 51 Cr EDTA) clearance is nowadays considered as an accurate and reproducible method for measuring glomerular filtration rate (GFR) in children. Normal values in function of age, corrected for body surface area, have been recently updated. However, much criticism has been expressed about the validity of body surface area correction. The aim of the present paper was to present the normal GFR values, not corrected for body surface area, with the associated percentile curves. For that purpose, the same patients as in the previous paper were selected, namely those with no recent urinary tract infection, having a normal left to right 99m Tc MAG3 uptake ratio and a normal kidney morphology on the early parenchymal images. A single blood sample method was used for 51 Cr EDTA clearance measurement. Clearance values, not corrected for body surface area, increased progressively up to the adolescence. The percentile curves were determined and allow, for a single patient, to estimate accurately the level of non-corrected clearance and the evolution with time, whatever the age. (orig.)

Can We Trust Real Time Measurements of Lung Deposited Surface Area Concentrations in Dust from Powder Nanomaterials?

DEFF Research Database (Denmark)

Levin, Marcus; Witschger, Olivier; Bau, Sebastien

2016-01-01

A comparison between various methods for real-time measurements of lung deposited surface area (LDSA) using spherical particles and powder dust with specific surface area ranging from 0.03 to 112 m2 g-1 was conducted. LDSA concentrations measured directly using Nanoparticle Surface Area Monitor...... gravimetrical filter measurements and specific surface areas. Measurement of LDSA showed very good correlation in measurements of spherical particles (R2 > 0.97, Ratio 1.0 to 1.04). High surface area nanomaterial powders showed a fairly reliable correlation between NSAM and Aerotrak (R2 0...... present. We conclude that there is currently insufficient reliability and comparability between methods in the measurement of LDSA concentrations. Further development is required to enable use of LDSA for reliable dose metric and regulatory enforcement of exposure....

Definition and coding of surface catchment areas: problems and solutions; Ausgrenzung und Verschluesselung oberirdischer Einzugsgebiete: Probleme und Loesungsansaetze

Energy Technology Data Exchange (ETDEWEB)

Wolff, A.; Mehl, D. [biota - Institut fuer Oekologische Forschung und Planung GmbH, Guestrow (Germany); Klitzsch, S. [Landesamt fuer Umwelt, Naturschutz und Geologie Mecklenburg-Vorpommern, Guestrow (Germany). Abt. Wasser und Boden

2000-12-01

Due to certain hydrographic situations there are some difficulties in application of the LAWA-directive 'Coding of catchment areas and streams'. In this paper, solutions are shown by means of examples from the federal state of Mecklenburg-Pomerania. Priorities of streams influenced by lakes and the Baltic Sea, branched and linked streams, urban streams and catchment areas without surface run-off were discussed. (orig.) [German] Die Anwendung der LAWA-Richtlinie zur Gebietsbezeichnung und Verschluesselung von Fliessgewaessern stoesst bei Vorliegen bestimmter hydrographischer Konstellationen auf Schwierigkeiten. Anhand von Fallbeispielen aus Mecklenburg-Vorpommern werden Loesungswege zur entsprechenden Problembehandlung aufgezeigt. Wesentliche Schwerpunkte sind daher durchflossene Seen, verzweigte und vernetzte Fliessgewaesser, Fliessgewaesser im staedtischen Bereich, die Problematik der Binnenentwaesserungsgebiete sowie Gewaesser im Ostseerueckstau. (orig.)

Surface and Internal Waves due to a Moving Load on a Very Large Floating Structure

Directory of Open Access Journals (Sweden)

Taro Kakinuma

2012-01-01

Full Text Available Interaction of surface/internal water waves with a floating platform is discussed with nonlinearity of fluid motion and flexibility of oscillating structure. The set of governing equations based on a variational principle is applied to a one- or two-layer fluid interacting with a horizontally very large and elastic thin plate floating on the water surface. Calculation results of surface displacements are compared with the existing experimental data, where a tsunami, in terms of a solitary wave, propagates across one-layer water with a floating thin plate. We also simulate surface and internal waves due to a point load, such as an airplane, moving on a very large floating structure in shallow water. The wave height of the surface or internal mode is amplified when the velocity of moving point load is equal to the surface- or internal-mode celerity, respectively.

A Three-Dimensional Enormous Surface Area Aluminum Microneedle Array with Nanoporous Structure

International Nuclear Information System (INIS)

Chen, P.Ch.; Zou, J.; Hsieh, Sh.J.; Chen, Ch.Ch.

2013-01-01

We proposed fabricating an aluminum micro needle array with a nano channel structure on the surface by combining micromachining, electrolyte polishing, and anodization methods. The micro needle array provides a three-dimensional (3D) structure that possesses several hundred times more surface area than a traditional nano channel template. Therefore, the micro needle array can potentially be used in many technology applications. This 3D micro needle array device can not only be used for painless injection or extraction, but also for storage, highly sensitive detection, drug delivery, and microelectrodes. From the calculation we made, the micro needle array not only increases surface area, but also enlarges the capacity of the device. Therefore, the micro needle array can further be used on many detecting, storing, or drug delivering applications.

Heteroatom Polymer-Derived 3D High-Surface-Area and Mesoporous Graphene Sheet-Like Carbon for Supercapacitors.

Science.gov (United States)

Sheng, Haiyang; Wei, Min; D'Aloia, Alyssa; Wu, Gang

2016-11-09

Current supercapacitors suffer from low energy density mainly due to the high degree of microporosity and insufficient hydrophilicity of their carbon electrodes. Development of a supercapacitor capable of simultaneously storing as much energy as a battery, along with providing sufficient power and long cycle stability would be valued for energy storage applications and innovations. Differing from commonly studied reduced graphene oxides, in this work we identified an inexpensive heteroatom polymer (polyaniline-PANI) as a carbon/nitrogen precursor, and applied a controlled thermal treatment at elevated temperature to convert PANI into 3D high-surface-area graphene-sheet-like carbon materials. During the carbonization process, various transition metals including Fe, Co, and Ni were added, which play critical roles in both catalyzing the graphitization and serving as pore forming agents. Factors including post-treatments, heating temperatures, and types of metal were found crucial for achieving enhanced capacitance performance on resulting carbon materials. Using FeCl 3 as precursor along with optimal heating temperature 1000 °C and mixed acid treatment (HCl+HNO 3 ), the highest Brunauer-Emmett-Teller (BET) surface area of 1645 m 2 g -1 was achieved on the mesopore dominant graphene-sheet-like carbon materials. The unique morphologies featured with high-surface areas, dominant mesopores, proper nitrogen doping, and 3D graphene-like structures correspond to remarkably enhanced electrochemical specific capacitance up to 478 Fg -1 in 1.0 M KOH at a scan rate of 5 mV s -1 . Furthermore, in a real two-electrode system of a symmetric supercapacitor, a specific capacitance of 235 Fg -1 using Nafion binder is obtained under a current density of 1 Ag -1 by galvanostatic charge-discharge tests in 6.0 M KOH. Long-term cycle stability up to 5000 cycles by using PVDF binder in electrode was systematically evaluated as a function of types of metals and current densities.

Carbon monoxide adsorption studies on Ru:Mn bimetallic catalysts supported on alumina, silica and titania supported for the determination of metal surface area overview

International Nuclear Information System (INIS)

Hussain, S.T.

1992-01-01

Supported Ru: Mn bimetallic samples were studied using CO-chemisorption on alumina, silica and titania supports for the determination of active metal site/metal surface area. The data indicates the presence of Mn on the surface of Ru. With the increase of Mn loadings a decrease in the CO adsorption occurred indicating that presence of Mn masks the active sites responsible for Co-adsorption. On the titania supported system reduced at high and low temperature the CO-chemisorption data suggest the unusual behaviour. This behaviour is possibly caused due to creation of new active surface sites. (author)

Genesis and Development of Soils along Different Geomorphic Surfaces in Kouh Birk Area, Mehrestan City

Directory of Open Access Journals (Sweden)

Mohammad Akbar Bahoorzahi

2017-02-01

Full Text Available Introduction: The optimum and sustainable use of soil is only possible with correct and complete understanding of its properties. The objectives of the present research were to study 1 genesis and development of soils related to different geomorphic surfaces in Kouh Birk Area (Mehrestan City, 2 Soil classification according to Soil Taxonomy (2014 and WRB (2014 systems, and 3 physicochemical properties, clay mineralogy and micromorphology of soils. Materials and Methods: Mean annual rainfall and soil temperature in the selected location are 153.46 mm and 19.6 oC, respectively. From geological point of view, the studied area is a part of west and south west zones and Flysch zone of east Iran. Soil temperature and moisture regimes of this part are thermic and aridic, respectively. Eight representative pedons on different surfaces including rock pediment, mantled pediment, Alluvial fan and Upper terraces were selected, sampled, and described. Routine physicochemical analyses, clay mineralogy, and micromorphological observations performed on soil samples. Soil reaction, texture, electrical conductivity, calcium carbonate, and gypsum were identified. Four samples including Bt horizon of pedon 1, Bk1 horizon of pedon 4, By2 horizon of pedon 5 and Bk1 horizon of pedon 7 were selected for clay mineralogy investigations. Four slides including Mg saturated, Mg saturated treated with ethylene glycol, K saturated, and K saturated heated up to 550 oC were analyzed. A Brucker X-Ray diffractometer at 40 kV and 30 mA was used for XRD analyses. Undisturbed soil samples from Bt horizon of pedon 1, Bk2 horizon of pedon 2, Btn horizon of pedon 3, By2 horizon of pedon 5, Bk1 horizon of pedon 7, and By1 horizon of pedon 8 were selected for micromorphological observations. A vestapol resin with stearic acid and cobalt as hardener was used for soil impregnation. Bk-Pol petrographic microscope was used for micromorphology investigations. Results and Discussion: Due to

Body surface area prediction in normal, hypermuscular, and obese mice.

Science.gov (United States)

Cheung, Michael C; Spalding, Paul B; Gutierrez, Juan C; Balkan, Wayne; Namias, Nicholas; Koniaris, Leonidas G; Zimmers, Teresa A

2009-05-15

Accurate determination of body surface area (BSA) in experimental animals is essential for modeling effects of burn injury or drug metabolism. Two-dimensional surface area is related to three-dimensional body volume, which in turn can be estimated from body mass. The Meeh equation relates body surface area to the two-thirds power of body mass, through a constant, k, which must be determined empirically by species and size. We found older values of k overestimated BSA in certain mice; thus we determined empirically k for various strains of normal, obese, and hypermuscular mice. BSA was computed from digitally scanned pelts and nonlinear regression analysis was used to determine the best-fit k. The empirically determined k for C57BL/6J mice of 9.82 was not significantly different from other inbred and outbred mouse strains of normal body composition. However, mean k of the nearly spheroid, obese lepr(db/db) mice (k = 8.29) was significantly lower than for normals, as were values for dumbbell-shaped, hypermuscular mice with either targeted deletion of the myostatin gene (Mstn) (k = 8.48) or with skeletal muscle specific expression of a dominant negative myostatin receptor (Acvr2b) (k = 8.80). Hypermuscular and obese mice differ substantially from normals in shape and density, resulting in considerably altered k values. This suggests Meeh constants should be determined empirically for animals of altered body composition. Use of these new, improved Meeh constants will allow greater accuracy in experimental models of burn injury and pharmacokinetics.

Optimized preparation for large surface area activated carbon from date (Phoenix dactylifera L.) stone biomass

International Nuclear Information System (INIS)

Danish, Mohammed; Hashim, Rokiah; Ibrahim, M.N. Mohamad; Sulaiman, Othman

2014-01-01

The preparation of activated carbon from date stone treated with phosphoric acid was optimized using rotatable central composite design of response surface methodology (RSM). The chemical activating agent concentration and temperature of activation plays a crucial role in preparation of large surface area activated carbons. The optimized activated carbon was characterized using thermogravimetric analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The results showed that the larger surface area of activated carbon from date stone can be achieved under optimum activating agent (phosphoric acid) concentration, 50.0% (8.674 mol L −1 ) and activation temperature, 900 °C. The Brunauer–Emmett–Teller (BET) surface area of optimized activated carbon was found to be 1225 m 2  g −1 , and thermogravimetric analysis revealed that 55.2% mass of optimized activated carbon was found thermally stable till 900 °C. The leading chemical functional groups found in the date stone activated carbon were aliphatic carboxylic acid salt ν(C=O) 1561.22 cm −1 and 1384.52 cm −1 , aliphatic hydrocarbons ν(C–H) 2922.99 cm −1 (C–H sym./asym. stretch frequency), aliphatic phosphates ν(P–O–C) 1054.09 cm −1 , and secondary aliphatic alcohols ν(O–H) 3419.81 cm −1 and 1159.83 cm −1 . - Highlights: • RSM optimization was done for the production of large surface area activated carbon. • Two independent variables with two responses were selected for optimization. • Characterization was done for surface area, morphology and chemical constituents. • Optimized date stone activated carbon achieved surface area 1225 m 2  g −1

Installation and performance evaluation of an indigenous surface area analyser

International Nuclear Information System (INIS)

Pillai, S.N.; Solapurkar, M.N.; Venkatesan, V.; Prakash, A.; Khan, K.B.; Kumar, Arun; Prasad, R.S.

2014-01-01

An indigenously available surface area analyser was installed inside glove box and checked for its performance by analyzing uranium oxide and thorium oxide powders at RMD. The unit has been made ready for analysis of Plutonium oxide powders after incorporating several important features. (author)

Prediction of residual stress distributions due to surface machining and welding and crack growth simulation under residual stress distribution

International Nuclear Information System (INIS)

Ihara, Ryohei; Katsuyama, JInya; Onizawa, Kunio; Hashimoto, Tadafumi; Mikami, Yoshiki; Mochizuki, Masahito

2011-01-01

Research highlights: → Residual stress distributions due to welding and machining are evaluated by XRD and FEM. → Residual stress due to machining shows higher tensile stress than welding near the surface. → Crack growth analysis is performed using calculated residual stress. → Crack growth result is affected machining rather than welding. → Machining is an important factor for crack growth. - Abstract: In nuclear power plants, stress corrosion cracking (SCC) has been observed near the weld zone of the core shroud and primary loop recirculation (PLR) pipes made of low-carbon austenitic stainless steel Type 316L. The joining process of pipes usually includes surface machining and welding. Both processes induce residual stresses, and residual stresses are thus important factors in the occurrence and propagation of SCC. In this study, the finite element method (FEM) was used to estimate residual stress distributions generated by butt welding and surface machining. The thermoelastic-plastic analysis was performed for the welding simulation, and the thermo-mechanical coupled analysis based on the Johnson-Cook material model was performed for the surface machining simulation. In addition, a crack growth analysis based on the stress intensity factor (SIF) calculation was performed using the calculated residual stress distributions that are generated by welding and surface machining. The surface machining analysis showed that tensile residual stress due to surface machining only exists approximately 0.2 mm from the machined surface, and the surface residual stress increases with cutting speed. The crack growth analysis showed that the crack depth is affected by both surface machining and welding, and the crack length is more affected by surface machining than by welding.

Structure, surface area and morphology of aluminas from thermal decomposition of Al(OH(CH3COO2 crystals

Directory of Open Access Journals (Sweden)

KIYOHARA PEDRO K.

2000-01-01

Full Text Available Crystalline aluminium hydroxiacetate was prepared by reaction between aluminium powder (ALCOA 123 and aqueous solution of acetic acid at 96ºC ±1ºC. The white powder of Al(OH(CH3COO2 is constituted by agglomerates of crystalline plates, having size about 10mum. The crystals were fired from 200ºC to 1550ºC, in oxidizing atmosphere and the products characterized by X-ray diffraction, scanning electron microscopy and surface area measurements by BET-nitrogen method. Transition aluminas are formed from heating at the following temperatures: gamma (300ºC; delta (750ºC; alpha (1050ºC. The aluminas maintain the original morphology of the Al(OHAc2 crystal agglomerates, up to 1050ºC, when sintering and coalescence of the alpha-alumina crystals start and proceed up to 1550ºC. High surface area aluminas are formed in the temperature range of 700ºC to 1100ºC; the maximum value of 198m²/g is obtained at 900ºC, with delta-alumina structure. The formation sequence of transition aluminas is similar to the sequence from well ordered boehmite, but with differences in the transition temperatures and in the development of high surface areas. It is suggested that the causes for these diversities between the two sequences from Al(OH Ac2 and boehmite are due to the different particle sizes, shapes and textures of the gamma-Al2O3 which acts as precursor for the sequence gamma- to alpha-Al2O3.

Escaping the correction for body surface area when calculating glomerular filtration rate in children

Energy Technology Data Exchange (ETDEWEB)

Piepsz, Amy; Tondeur, Marianne [CHU St. Pierre, Department of Radioisotopes, Brussels (Belgium); Ham, Hamphrey [University Hospital Ghent, Department of Nuclear Medicine, Ghent (Belgium)

2008-09-15

{sup 51}Cr ethylene diamine tetraacetic acid ({sup 51}Cr EDTA) clearance is nowadays considered as an accurate and reproducible method for measuring glomerular filtration rate (GFR) in children. Normal values in function of age, corrected for body surface area, have been recently updated. However, much criticism has been expressed about the validity of body surface area correction. The aim of the present paper was to present the normal GFR values, not corrected for body surface area, with the associated percentile curves. For that purpose, the same patients as in the previous paper were selected, namely those with no recent urinary tract infection, having a normal left to right {sup 99m}Tc MAG3 uptake ratio and a normal kidney morphology on the early parenchymal images. A single blood sample method was used for {sup 51}Cr EDTA clearance measurement. Clearance values, not corrected for body surface area, increased progressively up to the adolescence. The percentile curves were determined and allow, for a single patient, to estimate accurately the level of non-corrected clearance and the evolution with time, whatever the age. (orig.)

Small carpal bone surface area, a characteristic of Turner's syndrome

International Nuclear Information System (INIS)

Cleveland, R.H.; Done, S.; Correia, J.A.; Crawford, J.D.; Kushner, D.C.; Herman, T.E.

1985-01-01

An abnormality which has received little attention but may be easily recognized on radiographs of the hand of patients with Turner's syndrome is described. Eleven of thirty-one patients (35.5%) with Turner's syndrome were shown on radiographs of the hand to have a visually detectable smallness of the bone surface area of the carpus when compared to the area of the second through fifth metacarpals. Values for the ''C/M'' ratio (the area of the carpals divided by the area of the second through fifth metacarpals) were calculated for films of 31 individuals with gonadal dysgenesis and compared with those from bone age-matched films of seventy-six individuals with normal development of the hand and wrist. A consistent difference with minimal overlap was documented. (orig./WL)

Location of unaccessible implant surface areas during debridement in simulated peri-implantitis therapy.

Science.gov (United States)

Steiger-Ronay, Valerie; Merlini, Andrea; Wiedemeier, Daniel B; Schmidlin, Patrick R; Attin, Thomas; Sahrmann, Philipp

2017-11-28

An in vitro model for peri-implantitis treatment was used to identify areas that are clinically difficult to clean by analyzing the pattern of residual stain after debridement with commonly employed instruments. Original data from two previous publications, which simulated surgical (SA) and non-surgical (NSA) implant debridement on two different implant systems respectively, were reanalyzed regarding the localization pattern of residual stains after instrumentation. Two blinded examiners evaluated standardized photographs of 360 initially ink-stained dental implants, which were cleaned at variable defect angulations (30, 60, or 90°), using different instrument types (Gracey curette, ultrasonic scaler or air powder abrasive device) and treatment approaches (SA or NSA). Predefined implant surface areas were graded for residual stain using scores ranging from one (stain-covered) to six (clean). Score differences between respective implant areas were tested for significance by pairwise comparisons using Wilcoxon-rank-sum-tests with a significance level α = 5%. Best scores were found at the machined surface areas (SA: 5.58 ± 0.43, NSA: 4.76 ± 1.09), followed by the tips of the threads (SA: 4.29 ± 0.44, NSA: 4.43 ± 0.61), and areas between threads (SA: 3.79 ± 0.89, NSA: 2.42 ± 1.11). Apically facing threads were most difficult to clean (SA: 1.70 ± 0.92, NSA: 2.42 ± 1.11). Here, air powder abrasives provided the best results. Machined surfaces at the implant shoulder were well accessible and showed least amounts of residual stain. Apically facing thread surfaces constituted the area with most residual stain regardless of treatment approach.

Lp-dual affine surface area forms of Busemann–Petty type problems

Indian Academy of Sciences (India)

Associated with the notion of Lp-intersection body which was defined ... Lp-dual affine surface area; Lp-intersection body; Busemann–Petty ..... [11] Schneider R, Convex Bodies: The Brunn–Minkowski Theory (1993) (Cambridge: Cam-.

30 CFR 933.761 - Areas designated unsuitable for surface coal mining by Act of Congress.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Areas designated unsuitable for surface coal mining by Act of Congress. 933.761 Section 933.761 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... Congress. Part 761 of this chapter, Areas Designated Unsuitable for Coal Mining by Act of Congress, with...

A Mathematical Method to Calculate Tumor Contact Surface Area: An Effective Parameter to Predict Renal Function after Partial Nephrectomy.

Science.gov (United States)

Hsieh, Po-Fan; Wang, Yu-De; Huang, Chi-Ping; Wu, Hsi-Chin; Yang, Che-Rei; Chen, Guang-Heng; Chang, Chao-Hsiang

2016-07-01

We proposed a mathematical formula to calculate contact surface area between a tumor and renal parenchyma. We examined the applicability of using contact surface area to predict renal function after partial nephrectomy. We performed this retrospective study in patients who underwent partial nephrectomy between January 2012 and December 2014. Based on abdominopelvic computerized tomography or magnetic resonance imaging, we calculated the contact surface area using the formula (2*π*radius*depth) developed by integral calculus. We then evaluated the correlation between contact surface area and perioperative parameters, and compared contact surface area and R.E.N.A.L. (Radius/Exophytic/endophytic/Nearness to collecting system/Anterior/Location) score in predicting a reduction in renal function. Overall 35, 26 and 45 patients underwent partial nephrectomy with open, laparoscopic and robotic approaches, respectively. Mean ± SD contact surface area was 30.7±26.1 cm(2) and median (IQR) R.E.N.A.L. score was 7 (2.25). Spearman correlation analysis showed that contact surface area was significantly associated with estimated blood loss (p=0.04), operative time (p=0.04) and percent change in estimated glomerular filtration rate (p contact surface area and R.E.N.A.L. score independently affected percent change in estimated glomerular filtration rate (p contact surface area was a better independent predictor of a greater than 10% change in estimated glomerular filtration rate compared to R.E.N.A.L. score (AUC 0.86 vs 0.69). Using this simple mathematical method, contact surface area was associated with surgical outcomes. Compared to R.E.N.A.L. score, contact surface area was a better predictor of functional change after partial nephrectomy. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Outlining precision boundaries among areas with different variability standards using magnetic susceptibility and geomorphic surfaces

OpenAIRE

Matias,Sammy S. R.; Marques Júnior,José; Siqueira,Diego S.; Pereira,Gener T.

2014-01-01

There is an increasing demand for detailed maps that represent in a simplified way the knowledge of the variability of a particular area or region maps. The objective was to outline precision boundaries among areas with different accuracy variability standards using magnetic susceptibility and geomorphic surfaces. The study was conducted in an area of 110 ha, which identified three compartment landscapes based on the geomorphic surfaces model. To determinate pH, organic matter, phosphorus, po...

Influence of Ear Surface Area on Heat Tolerance of Composite ...

African Journals Online (AJOL)

Relative importance of ear surface area on heat tolerance of composite rabbit population was evaluated. The study was conducted during the dry and rainy seasons, climatic data were recorded to obtain categorical heat stress index. Physiological parameters, growth performance, ear length and ear width of the rabbits ...

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

Science.gov (United States)

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

Research on the surface water quality in mining influenced area in north-western part of Romania

Directory of Open Access Journals (Sweden)

Smical Irina

2015-01-01

Full Text Available The paper highlights the current situation of the quality of surface water in the areas influenced by mining activities in the north-western part of Romania. In this respect a series of investigations have been conducted regarding the contamination with heavy metals of the water of the Someş and Tisa hydro- graphic Basins, which cover the northern part of Maramures County and the south-western area of Maramures County, respectively. The results of the comparative research refer to the period between 1999 and 2011 and reveal the specific heavy metal ions of mining activity: Fe, Mn, Zn, Cu, Pb Cd and Ni, as well as the water pH. The presented values as annual average values reveal an increase in several heavy metals after the closure of mines, which is due to the lack of effectiveness of the closure and of the conservation of the mine galleries, as well as of the impaired functioning of the mining wastewater treatment plants.

Nanoparticles in natural systems I: The effective reactive surface area of the natural oxide fraction in field samples

Science.gov (United States)

Hiemstra, Tjisse; Antelo, Juan; Rahnemaie, Rasoul; van Riemsdijk, Willem H.

2010-01-01

Information on the particle size and reactive surface area of natural samples is essential for the application of surface complexation models (SCM) to predict bioavailability, toxicity, and transport of elements in the natural environment. In addition, this information will be of great help to enlighten views on the formation, stability, and structure of nanoparticle associations of natural organic matter (NOM) and natural oxide particles. Phosphate is proposed as a natively present probe ion to derive the effective reactive surface area of natural samples. In the suggested method, natural samples are equilibrated (⩾10 days) with 0.5 M NaHCO 3 (pH = 8.5) at various solid-solution ratios. This matrix fixes the pH and ionic strength, suppresses the influence of Ca 2+ and Mg 2+ ions by precipitation these in solid carbonates, and removes NOM due to the addition of activated carbon in excess, collectively leading to the dominance of the PO 4-CO 3 interaction in the system. The data have been interpreted with the charge distribution (CD) model, calibrated for goethite, and the analysis results in an effective reactive surface area (SA) and a reversibly bound phosphate loading Γ for a series of top soils. The oxidic SA varies between about 3-30 m 2/g sample for a large series of representative agricultural top soils. Scaling of our data to the total iron and aluminum oxide content (dithionite-citrate-bicarbonate extractable), results in the specific surface area between about 200-1200 m 2/g oxide for most soils, i.e. the oxide particles are nano-sized with an equivalent diameter in the order of ˜1-10 nm if considered as non-porous spheres. For the top soils, the effective surface area and the soil organic carbon fraction are strongly correlated. The oxide particles are embedded in a matrix of organic carbon (OC), equivalent to ˜1.4 ± 0.2 mg OC/m 2 oxide for many soils of the collection, forming a NOM-mineral nanoparticle association with an average NOM volume

External Validation of Contact Surface Area as a Predictor of Postoperative Renal Function in Patients Undergoing Partial Nephrectomy.

Science.gov (United States)

Haifler, Miki; Ristau, Benjamin T; Higgins, Andrew M; Smaldone, Marc C; Kutikov, Alexander; Zisman, Amnon; Uzzo, Robert G

2017-09-20

We sought to externally validate a mathematical formula for tumor contact surface area as a predictor of postoperative renal function in patients undergoing partial nephrectomy for renal cell carcinoma. We queried a prospectively maintained kidney cancer database for patients who underwent partial nephrectomy between 2014 and 2016. Contact surface area was calculated using data obtained from preoperative cross-sectional imaging. The correlation between contact surface area and perioperative variables was examined. The correlation between postoperative renal functional outcomes, contact surface area and the R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar lines and tumor touches main renal artery or vein) nephrometry score was also assessed. A total of 257 patients who underwent partial nephrectomy had sufficient data to enter the study. Median contact surface area was 14.5 cm 2 (IQR 6.2-36) and the median nephrometry score was 9 (IQR 7-10). Spearman correlation analysis showed that contact surface area correlated with estimated blood loss (r s = 0.42, p contact surface area and nephrometry score were independent predictors of the absolute change in the estimated glomerular filtration rate (each p contact surface area was a better predictor of a greater than 20% postoperative decline in the estimated glomerular filtration rate compared with the nephrometry score (AUC 0.94 vs 0.80). Contact surface area correlated with the change in postoperative renal function after partial nephrectomy. It can be used in conjunction with the nephrometry score to counsel patients about the risk of renal functional decline after partial nephrectomy. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Stereological estimation of surface area and barrier thickness of fish gills in vertical sections.

Science.gov (United States)

Da Costa, Oscar T F; Pedretti, Ana Carolina E; Schmitz, Anke; Perry, Steven F; Fernandes, Marisa N

2007-01-01

Previous morphometric methods for estimation of the volume of components, surface area and thickness of the diffusion barrier in fish gills have taken advantage of the highly ordered structure of these organs for sampling and surface area estimations, whereas the thickness of the diffusion barrier has been measured orthogonally on perpendicularly sectioned material at subjectively selected sites. Although intuitively logical, these procedures do not have a demonstrated mathematical basis, do not involve random sampling and measurement techniques, and are not applicable to the gills of all fish. The present stereological methods apply the principles of surface area estimation in vertical uniform random sections to the gills of the Brazilian teleost Arapaima gigas. The tissue was taken from the entire gill apparatus of the right-hand or left-hand side (selected at random) of the fish by systematic random sampling and embedded in glycol methacrylate for light microscopy. Arches from the other side were embedded in Epoxy resin. Reference volume was estimated by the Cavalieri method in the same vertical sections that were used for surface density and volume density measurements. The harmonic mean barrier thickness of the water-blood diffusion barrier was calculated from measurements taken along randomly selected orientation lines that were sine-weighted relative to the vertical axis. The values thus obtained for the anatomical diffusion factor (surface area divided by barrier thickness) compare favourably with those obtained for other sluggish fish using existing methods.

Molecularly-Limited Fractal Surface Area of Mineral Powders

Directory of Open Access Journals (Sweden)

Petr Jandacka

2016-05-01

Full Text Available The topic of the specific surface area (SSA of powders is not sufficiently described in the literature in spite of its nontrivial contribution to adsorption and dissolution processes. Fractal geometry provides a way to determine this parameter via relation SSA ~ x(D − 3s(2 − D, where x (m is the particle size and s (m is a scale. Such a relation respects nano-, micro-, or macro-topography on the surface. Within this theory, the fractal dimension 2 ≤ D < 3 and scale parameter s plays a significant role. The parameter D may be determined from BET or dissolution measurements on several samples, changing the powder particle sizes or sizes of adsorbate molecules. If the fractality of the surface is high, the SSA does not depend on the particle size distribution and vice versa. In this paper, the SSA parameter is analyzed from the point of view of adsorption and dissolution processes. In the case of adsorption, a new equation for the SSA, depending on the term (2 − D∙(s2 − sBET/sBET, is derived, where sBET and s2 are effective cross-sectional diameters for BET and new adsorbates. Determination of the SSA for the dissolution process appears to be very complicated, since the fractality of the surface may change in the process. Nevertheless, the presented equations have good application potential.

Using PS-InSAR to detect surface deformation in geothermal areas of West Java in Indonesia

Science.gov (United States)

Maghsoudi, Yasser; van der Meer, Freek; Hecker, Christoph; Perissin, Daniele; Saepuloh, Asep

2018-02-01

In this paper, the Persistent Scatterer InSAR (PS-InSAR) technique is applied in order to investigate the ground deformation in and around two geothermal areas in West Java, Indonesia. Two time-series of ALOS PALSAR and Sentinel-1A acquisitions, covering the period from 2007 to 2009 and 2015-2016, are analysed. The first case study examines the Wayang Windu geothermal zone where the PS-InSAR analysis provides an overview of the surface deformation around a geothermal reservoir. Uplift is observed around the injection wells in the area. The second example involves the use of the PS-InSAR technique over a more recent geothermal system in Patuha field. Again, a pattern of uplift was observed around the only available injection well in the area. Due to the dense vegetation coverage of the geothermal areas in West Java, the longer wavelength ALOS PALSAR data is provides better results by identifying a larger number of PS points. Additionally, experiments have been carried out to compare the resulting deformation with another example of the fluid migration process i.e. water extraction in Bandung basin. The potential of sentinel-1A and ALOS PALSR data are compared in all the experiments.

Climatic change due to land surface alterations

Energy Technology Data Exchange (ETDEWEB)

Franchito, S.H.; Rao, V.B.

1992-01-01

A primitive equations global zonally averaged climate model is developed. The model includes biofeedback mechanisms. For the Northern Hemisphere the parameterization of biofeedback mechanisms is similar to that used by Gutman et al. For the Southern Hemisphere new parameterizations are derived. The model simulates reasonably well the mean annual zonally averaged climate and geobotanic zones. Deforestation, desertification, and irrigation experiments are performed. In the case of deforestation and desertification there is a reduction in the surface net radiation, evaporation, and precipitation and an increase in the surface temperature. In the case of irrigation experiment opposite changes occurred. In all the cases considered the changes in evapotranspiration overcome the effect of surface albedo modification. In all the experiments changes are smaller in the Southern Hemisphere.

Accessible surface area from NMR chemical shifts

Energy Technology Data Exchange (ETDEWEB)

Hafsa, Noor E.; Arndt, David; Wishart, David S., E-mail: david.wishart@ualberta.ca [University of Alberta, Department of Computing Science (Canada)

2015-07-15

Accessible surface area (ASA) is the surface area of an atom, amino acid or biomolecule that is exposed to solvent. The calculation of a molecule’s ASA requires three-dimensional coordinate data and the use of a “rolling ball” algorithm to both define and calculate the ASA. For polymers such as proteins, the ASA for individual amino acids is closely related to the hydrophobicity of the amino acid as well as its local secondary and tertiary structure. For proteins, ASA is a structural descriptor that can often be as informative as secondary structure. Consequently there has been considerable effort over the past two decades to try to predict ASA from protein sequence data and to use ASA information (derived from chemical modification studies) as a structure constraint. Recently it has become evident that protein chemical shifts are also sensitive to ASA. Given the potential utility of ASA estimates as structural constraints for NMR we decided to explore this relationship further. Using machine learning techniques (specifically a boosted tree regression model) we developed an algorithm called “ShiftASA” that combines chemical-shift and sequence derived features to accurately estimate per-residue fractional ASA values of water-soluble proteins. This method showed a correlation coefficient between predicted and experimental values of 0.79 when evaluated on a set of 65 independent test proteins, which was an 8.2 % improvement over the next best performing (sequence-only) method. On a separate test set of 92 proteins, ShiftASA reported a mean correlation coefficient of 0.82, which was 12.3 % better than the next best performing method. ShiftASA is available as a web server ( http://shiftasa.wishartlab.com http://shiftasa.wishartlab.com ) for submitting input queries for fractional ASA calculation.

On Assessment and Estimation of Potential Losses due to Land Subsidence in Urban Areas of Indonesia

Science.gov (United States)

Abidin, Hasanuddin Z.; Andreas, Heri; Gumilar, Irwan; Sidiq, Teguh P.

2016-04-01

Land subsidence is natural-anthropogenic hazard affecting several large urban areas in Indonesia, i.e. Jakarta, Bandung and Semarang. Geodetic based results from various techniques (e.g. Leveling, GPS and InSAR) show that land subsidence rates in all three cities generally have spatial and temporal variations, and their magnitude is in average about 5-10 cm/year. The impacts of subsidence in those cities can be seen in the field in various forms such as cracking of permanent constructions and roads, tilting of houses and buildings, 'sinking' of houses and buildings, changes in river canal and drain flow systems, wider expansion of coastal and/or inland flooding areas, and increased inland sea water intrusion. These impacts can be categorized into infrastructure, environmental, economic, and social impacts. The potential losses due to land subsidence in urban areas are actually quite significant. Related infrastructural, social and environmental costs due to direct and indirect impacts of land subsidence are economically quite significant, and can not be underestimated in sustainable urban development. The planning, development and maintenance costs of building and infrastructures in the affected areas are usually much higher than the normal situation. The collateral impact of coastal subsidence in Jakarta and Semarang, in the form of coastal flooding during high tides is also quite damaging. This repeated coastal flooding in several areas along the coast will deteriorate the structure and function of building and infrastructures, badly influences the quality of the living environment and life (e.g. health and sanitation condition), and also disrupts economic and social activities in the affected areas. As in the case of Bandung, inland subsidence also has a quite significant impact on inland flooding phenomena, since it will theoretically lead to expanded coverage and deeper water depth of flooded (inundated) areas. Since the direct and indirect impacts of

Effects of Surface Treatment of Activated Carbon on Its Surface and Cr(VI) Adsorption Characteristics

Energy Technology Data Exchange (ETDEWEB)

Park, Soo Jin; Jang, Yu Sin [Advanced Materials Division., Korea Research Institute of Chimical Technology, Taejon (Korea)

2001-04-01

In this work, the effect of surface treatments on activated carbons (ACs) has been studied in the context of gas and liquid adsorption behaviors. The chemical solutions used in this experiment were 35% sodium hydroxide, and these were used for the acidic and basic treatments, respectively. The surface properties have been determined by pH, acid-base values, and FT-IR. The adsorption isotherms of Cr(VI) ion on activated carbons have been studied with the 5 mg/l concentration at ambient temperature. N{sub 2} adsorption isotherm characteristics, which include the specific surface area, micro pore volume, and microporosity, were determined by BET and Boer's-plot methods. In case of the acidic treatment of activated carbons, it was observed that the adsorption of Cr(VI) ion was more effective due to the increase acid value (or acidic functional group) of activated carbon surfaces. However, the basic treatment on activated carbons was caused no significant effects, probably due to the decreased specific surface area and total pore volume. 27 refs., 7 figs., 4 tabs.

Extruded Al-Al{sub 2}O{sub 3} composites formed in situ during consolidation of ultrafine Al powders: Effect of the powder surface area

Energy Technology Data Exchange (ETDEWEB)

Balog, Martin, E-mail: martin.balog@savba.sk [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Bratislava (Slovakia); Simancik, Frantisek [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Bratislava (Slovakia); Walcher, Martin; Rajner, Walter [NMD - New Materials Development GmbH, St. Pantaleon (Austria); Poletti, Cecilia [Institute of Materials Science and Welding, Graz University of Technology, Kopernikusgasse 24/I, A8010 Graz (Austria)

2011-11-25

Highlights: {yields} 25 gas atomised Al 99.5% powders with particle size <10 {mu}m were hot extruded. {yields} The strength of compacts was closely related to powder surface area. {yields} Grain boundary strengthening was enhanced by the presence of in situ Al{sub 2}O{sub 3} dispersoids. {yields} Compacts showed good thermal stability due to grain pinning of Al{sub 2}O{sub 3} dispersoids. - Abstract: Twenty-five samples of commercially available, gas-atomised Al (99.5%) powders with particle sizes <10 {mu}m were hot extruded into Al-Al{sub 2}O{sub 3} composites formed in situ during extrusion. The effect of particle size, surface area, oxygen content and atomisation atmosphere of the powder on the microstructure and mechanical properties of the extruded compacts were studied by Brunauer, Emmett, Teller (BET) analysis, hot gas extraction, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and tensile tests. Thermal stability of the compacts and the individual strengthening mechanisms operating in the compacts were discussed. It was found that the properties of the compacts stemmed from the extraordinary grain boundary strengthening effect of the ultrafine-grained compacts due to their microstructures. The efficiency of the grain boundary strengthening was significantly enhanced by the presence of nano-metric Al{sub 2}O{sub 3} dispersoids introduced in situ. The strength of the compacts was closely related to the surface area of the powder particles. In addition, the entrapped gasses and chemically bonded humidity had a negative effect on the mechanical properties of the compacts.

Synthesis of porous carbon/silica nanostructured microfiber with ultrahigh surface area

Science.gov (United States)

Zhou, Dan; Dong, Yan; Cui, Liru; Lin, Huiming; Qu, Fengyu

2014-12-01

Carbon/silica-nanostructured microfibers were synthesized via electrospinning method using phenol-formaldehyde resin and tetraethyl orthosilicate as carbon and silica precursor with triblock copolymer Pluronic P123 as soft template. The prepared samples show uniform microfiber structure with 1 μm in diameter and dozens of microns in length. Additionally, the mesopores in the material is about 2-6 nm. When the silica component was removed by HF, the porous carbon microfibers (PCMFs) were obtained. In addition, after the carbon/silica composites were calcined in air, the porous silica microfibers (PSiMFs) were obtained, revealing the converse porous nanostructure as PCMFs. It is a simple way to prepare PCMFs and PSiMFs with silica and carbon as the template to each other. Additionally, PCMFs possess an ultrahigh specific surface area (2,092 m2 g-1) and large pore volume. The electrochemical performance of the prepared PCMF material was investigated in 6.0 M KOH electrolyte. The PCMF electrode exhibits a high specific capacitance (252 F g-1 at 0.5 A g-1). Then, superior cycling stability (97 % retention after 4,000 cycles) mainly is due to its unique nanostructure.

Indexing Glomerular Filtration Rate to Body Surface Area

DEFF Research Database (Denmark)

Redal-Baigorri, Belén; Rasmussen, Knud; Heaf, James Goya

2014-01-01

BACKGROUND: Kidney function is mostly expressed in terms of glomerular filtration rate (GFR). A common feature is the expression as ml/min per 1.73 m(2) , which represents the adjustment of the individual kidney function to a standard body surface area (BSA) to allow comparison between individuals....... We investigated the impact of indexing GFR to BSA in cancer patients, as this BSA indexation might affect the reported individual kidney function. METHODS: Cross-sectional study of 895 adults who had their kidney function measured with (51) chrome ethylene diamine tetraacetic acid. Mean values of BSA...

Asymptotic variance of grey-scale surface area estimators

DEFF Research Database (Denmark)

Svane, Anne Marie

Grey-scale local algorithms have been suggested as a fast way of estimating surface area from grey-scale digital images. Their asymptotic mean has already been described. In this paper, the asymptotic behaviour of the variance is studied in isotropic and sufficiently smooth settings, resulting...... in a general asymptotic bound. For compact convex sets with nowhere vanishing Gaussian curvature, the asymptotics can be described more explicitly. As in the case of volume estimators, the variance is decomposed into a lattice sum and an oscillating term of at most the same magnitude....

Correlation of lung surface area to apoptosis and proliferation in human emphysema.

Science.gov (United States)

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.

Tritium surface loading due to contamination of rainwater from atmospheric release at NAPS (2011)

International Nuclear Information System (INIS)

Gautam, Y.P.; Sharma, Saivajay; Rao, K.S.; Singh, Bhikam; Kumar, Avinash; Ravi, P.M.

2012-01-01

Annual tritium (HTO) surface loading has been measured and calculated for the year 2011 within 0.8 km distance from 145 m high stack of Narora Atomic Power Station (NAPS) at eight locations in different directions. The technique for measured values consists of the summation of product of tritium concentration (Bq/l) in daily rainfall samples and daily rainfall (mm). Tritium surface loading studies at NAPS reveal that a fraction 1.01E-03 of total annual tritium released through stack gets deposited on the surface due to washout/rainout of plume within 0.8 km radial distance from stack. The range of deposition velocity, Vw (m.s -1 ) i.e., the ratio of annual tritium surface loading W (Bq. m -2 .s -1 ) and annual mean tritium concentration in air, c 0 (Bq.m -3 ) at three locations for the years 2011 is found to be 6.12E-04 to 2.89E-03. The average value for wet deposition velocity V w for NAPS site is estimated as 3.17E-03 m.s -1 . (author)

Assessment of the surface chemistry of carbon blacks by TGA-MS, XPS and inverse gas chromatography using statistical chemometric analysis

International Nuclear Information System (INIS)

Strzemiecka, Beata; Voelkel, Adam; Donate-Robles, Jessica; Martín-Martínez, José Miguel

2014-01-01

Highlights: • Carbon blacks with lower specific surface area had basic character (electron donor) due to C=O and C-O groups. • Carbon blacks with higher specific surface area had acidic character (acceptor electron) due to OH groups. • Total surface energy and its dispersive component of carbon blacks increased by increasing their specific surface area. (table) - Abstract: Four carbon blacks with different specific surface areas and surface chemistries (C32, C71, C159 and C178) were analyzed by transmission electron microscopy (TEM) and nitrogen adsorption isotherms at 77 K. Their surface chemistries were analyzed by X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis coupled with mass spectrometry (TGA-MS) and inverse gas chromatography (IGC). The carbon blacks contained 2.7–5.8 wt% volatiles corresponding to -OH, C-O, C=O and COO groups. The surface chemistry parameters obtained with the different experimental techniques were inter-related by using chemometric statistical analysis tools. The application of this methodology showed that the carbon blacks with lower specific surface area (C32 and C71) had basic character (electron donor) mainly due to C=O and C-O groups, whereas the carbon black with the highest specific surface area (C178) showed acidic character (acceptor electron) due to its high content of OH groups. Moreover, the total surface energy and the dispersive component of the surface energy of the carbon blacks increased with the increase of their specific surface area. In general the specific interactions of the carbon blacks also increased with the increase of their specific surface area although C71 is exceptional due to higher oxygen content corresponding to C-O groups

Surface area-burnoff correlation for the steam--graphite reaction

International Nuclear Information System (INIS)

Stark, W.A. Jr.; Malinauskas, A.P.

1977-01-01

The oxidation of core graphite by steam of air represents a problem area of significant concern in safety analyses for the high temperature gas cooled reactor (HTGR). Core and core-support graphite integrity and strength deteriorate with oxidation of the graphite, and oxidation furthermore could affect the rate of fission product release under upset conditions. Consequently, modeling of core response during steam or air ingress conditions requires an expression for the rate of graphite interaction with those impurities. The steam--graphite reaction in particular is a complex interaction of mass transport within the graphite with chemi-sorption and reaction on accessible surfaces; experimental results from graphite to graphite are highly variable, and the description of the reaction is not yet completely consistent. A simple etch pit model relating surface area to burnoff has been proposed and shown to provide reasonable correlation with experimental data obtained from steam oxidation studies of nuclear grade H-327 graphite. Unaccounted differences between theory and experiment arise at burnoffs exceeding 3 to 5 percent. The model, while not complete nor comprehensive, is consistent with experimental observations of graphite oxidation by O 2 (air), CO 2 , or H 2 O, and could have some utility in safety analysis

Extruded Al-Al2O3 composites formed in situ during consolidation of ultrafine Al powders: Effect of the powder surface area

International Nuclear Information System (INIS)

Balog, Martin; Simancik, Frantisek; Walcher, Martin; Rajner, Walter; Poletti, Cecilia

2011-01-01

Highlights: → 25 gas atomised Al 99.5% powders with particle size 2 O 3 dispersoids. → Compacts showed good thermal stability due to grain pinning of Al 2 O 3 dispersoids. - Abstract: Twenty-five samples of commercially available, gas-atomised Al (99.5%) powders with particle sizes 2 O 3 composites formed in situ during extrusion. The effect of particle size, surface area, oxygen content and atomisation atmosphere of the powder on the microstructure and mechanical properties of the extruded compacts were studied by Brunauer, Emmett, Teller (BET) analysis, hot gas extraction, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and tensile tests. Thermal stability of the compacts and the individual strengthening mechanisms operating in the compacts were discussed. It was found that the properties of the compacts stemmed from the extraordinary grain boundary strengthening effect of the ultrafine-grained compacts due to their microstructures. The efficiency of the grain boundary strengthening was significantly enhanced by the presence of nano-metric Al 2 O 3 dispersoids introduced in situ. The strength of the compacts was closely related to the surface area of the powder particles. In addition, the entrapped gasses and chemically bonded humidity had a negative effect on the mechanical properties of the compacts.

Solvent accessible surface area (ASA) of simulated phospholipid membranes

DEFF Research Database (Denmark)

Tuchsen, E.; Jensen, Morten Østergaard; Westh, P.

2003-01-01

The membrane-solvent interface has been investigated through calculations of the solvent accessible surface area (ASA) for simulated membranes of DPPC and POPE. For DPPC at 52 degreesC we found an ASA of 126 +/- 8 Angstrom(2) per lipid molecule, equivalent to twice the projected lateral area......, even the most exposed parts of the PC head-group show average ASAs of less than half of its maximal or 'fully hydrated' value. The average ASA of a simulated POPE membrane was 96 +/- 7 Angstrom(2) per lipid. The smaller value than for DPPC reflects much lower ASA of the ammonium ion, which is partially...... compensated by increased exposure of the ethylene and phosphate moieties. The ASA of the polar moieties Of (PO4, NH3 and COO) constitutes 65% of the total accessible area for POPE, making this interface more polar than that of DPPC. It is suggested that ASA information can be valuable in attempts...

Workbench surface editor of brain cortical surface

Science.gov (United States)

Dow, Douglas E.; Nowinski, Wieslaw L.; Serra, Luis

1996-04-01

We have developed a 3D reach-in tool to manually reconstruct 3D cortical surface patches from 2D brain atlas images. The first application of our cortex editor is building 3D functional maps, specifically Brodmann's areas. This tool may also be useful in clinical practice to adjust incorrectly mapped atlas regions due to the deforming effect of lesions. The cortex editor allows a domain expert to control the correlation of control points across slices. Correct correlation has been difficult for 3D reconstruction algorithms because the atlas slices are far apart and because of the complex topology of the cortex which differs so much from slice to slice. Also, higher precision of the resulting surfaces is demanded since these define 3D brain atlas features upon which future stereotactic surgery may be based. The cortex editor described in this paper provides a tool suitable for a domain expert to use in defining the 3D surface of a Brodmann's area.

Dye-Sensitized Solar Cells Based on High Surface Area Nanocrystalline Zinc Oxide Spheres

Directory of Open Access Journals (Sweden)

Pavuluri Srinivasu

2011-01-01

Full Text Available High surface area nanocrystalline zinc oxide material is fabricated using mesoporous nanostructured carbon as a sacrificial template through combustion process. The resulting material is characterized by XRD, N2 adsorption, HR-SEM, and HR-TEM. The nitrogen adsorption measurement indicates that the materials possess BET specific surface area ca. 30 m2/g. Electron microscopy images prove that the zinc oxide spheres possess particle size in the range of 0.12 μm–0.17 μm. The nanocrystalline zinc oxide spheres show 1.0% of energy conversion efficiency for dye-sensitized solar cells.

Tritium surface loading due to contamination of rainwater from atmospheric release at NAPS

International Nuclear Information System (INIS)

Sharma, L.N.; Dube, B.; Varakhedkar, V.K.

2001-01-01

Annual tritium (HTO) surface loading has been measured and calculated for the year 1998-99 within 0.8 km distance from 145m high stack of Narora Atomic Power Station (NAPS) at eight locations in different directions. The technique for measured values consists of the summation of product of tritium concentration (Bq/l) in daily rainfall samples and daily rainfall (mm) whereas that for calculated values having the use of prevailing meteorological conditions and average tritium release rate during a year. The ratios of measured and calculated values of tritium surface loading during the years 1998-99 are found to be in the range of 0.18 to 6.97. Tritium surface loading studies at NAPS reveal that a fraction 1.7E-03 of total annual tritium released through stack gets deposited on the surface due to washout / rainout of plume within 0.8 km radial distance from stack. The range of deposition velocity, V w (m.s - 1 ) i.e the ratio of annual tritium surface loading W(Bq.m - 2 . s - 1 ) and annual mean tritium concentration in air, χo(Bq.m - 3) at three locations for the years 1998-99 is found to be 5.59E-04 to 5.99E-03 ms - 1 . The average value for wet deposition velocity V bar w for NAPS site is estimated as 2.92E-03 m.s - 1. (author)

Assessment of risk due to vehicle accident for the plutonium solution transfer from H-area to F-area

International Nuclear Information System (INIS)

Sarrack, A.G.

1996-09-01

Transporting radioactive material onsite (intrasite transfers) via truck or train must be performed in a safe manner. Adequate safety is assured for each transfer, as documented in the corresponding Onsite Safety Assessment (OSA). One aspect of the OSA is to show that the package to be used for the transfer meets onsite acceptance criteria. The activity being analyzed in this report is the movement of plutonium solution with greater than 20 curies, all reasonable mitigative controls will be implemented to minimize the likelihood of an accidental release, and a probabilistic analysis will be used to evaluate the risk associated with the move. The purpose of this report is to document the evaluation of risk due to vehicle accident associated with transporting plutonium solution from H-area to F-area. Included in the report is a list of the required mitigative controls which reduce the predicted accident and release frequencies to those reported in the summary

Surface area of lactose and lactose granulates on consolidation and compaction

NARCIS (Netherlands)

Riepma, Klaas Alouis

1993-01-01

This dissertation discusses the effect of short time storage at different conditions on the strength and the specific BET surface area of lactose tablets. In addition, some aspects are studied of the consolidation and compaction properties of crystalline lactose fractions in heterogeneous systems.

Comparison of 2 root surface area measurement methods: 3-dimensional laser scanning and cone-beam computed tomography

International Nuclear Information System (INIS)

Tasanapanont, Jintana; Apisariyakul, Janya; Wattanachai, Tanapan; Jotikasthira, Dhirawat; Sriwilas, Patiyut; Midtboe, Marit

2017-01-01

The aim of this study was to compare the use of 3-dimensional (3D) laser scanning and cone-beam computed tomography (CBCT) as methods of root surface measurement. Thirty teeth (15 maxillary first premolars and 15 mandibular first premolars) from 8 patients who required extractions for orthodontic treatment were selected. Before extraction, pre-treatment CBCT images of all the patients were recorded. First, a CBCT image was imported into simulation software (Mimics version 15.01; Materialise, Leuven, Belgium) and the root surface area of each tooth was calculated using 3-Matic (version 7.01, Materialise, Leuven, Belgium). After extraction, all the teeth were scanned and the root surface area of each extracted tooth was calculated. The root surface areas calculated using these 2 measurement methods were analyzed using the paired t-test (P<.05). Correlations between the 2 methods were determined by calculating the Pearson correlation coefficient. The intraclass correlation coefficient (ICC) was used to assess intraobserver reliability. The root surface area measurements (230.11±41.97 mm"2) obtained using CBCT were slightly greater than those (229.31±42.46 mm2) obtained using 3D laser scanning, but not significantly (P=.425). A high Pearson correlation coefficient was found between the CBCT and the 3D laser scanner measurements. The intraobserver ICC was 1.000 for 3D laser scanning and 0.990 for CBCT. This study presents a novel CBCT approach for measuring the root surface area; this technique can be used for estimating the root surface area of non-extracted teeth

Comparison of 2 root surface area measurement methods: 3-dimensional laser scanning and cone-beam computed tomography

Energy Technology Data Exchange (ETDEWEB)

Tasanapanont, Jintana; Apisariyakul, Janya; Wattanachai, Tanapan; Jotikasthira, Dhirawat [Dept. of Orthodontics and Pediatric Dentistry, Faculty of Dentistry, Chiang Mai University, Chiang Mai (Thailand); Sriwilas, Patiyut [Dept. of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok (Thailand); Midtboe, Marit [Dept. of Clinical Dentistry - Orthodontics, Faculty of Medicine and Dentistry, University of Bergen, Bergen (Norway)

2017-06-15

The aim of this study was to compare the use of 3-dimensional (3D) laser scanning and cone-beam computed tomography (CBCT) as methods of root surface measurement. Thirty teeth (15 maxillary first premolars and 15 mandibular first premolars) from 8 patients who required extractions for orthodontic treatment were selected. Before extraction, pre-treatment CBCT images of all the patients were recorded. First, a CBCT image was imported into simulation software (Mimics version 15.01; Materialise, Leuven, Belgium) and the root surface area of each tooth was calculated using 3-Matic (version 7.01, Materialise, Leuven, Belgium). After extraction, all the teeth were scanned and the root surface area of each extracted tooth was calculated. The root surface areas calculated using these 2 measurement methods were analyzed using the paired t-test (P<.05). Correlations between the 2 methods were determined by calculating the Pearson correlation coefficient. The intraclass correlation coefficient (ICC) was used to assess intraobserver reliability. The root surface area measurements (230.11±41.97 mm{sup 2}) obtained using CBCT were slightly greater than those (229.31±42.46 mm2) obtained using 3D laser scanning, but not significantly (P=.425). A high Pearson correlation coefficient was found between the CBCT and the 3D laser scanner measurements. The intraobserver ICC was 1.000 for 3D laser scanning and 0.990 for CBCT. This study presents a novel CBCT approach for measuring the root surface area; this technique can be used for estimating the root surface area of non-extracted teeth.

Damping of surface waves due to oil emulsions in application to ocean remote sensing

Science.gov (United States)

Sergievskaya, I.; Ermakov, S.; Lazareva, T.; Lavrova, O.

2017-10-01

Applications of different radar and optical methods for detection of oil pollutions based on the effect of damping of short wind waves by surface films have been extensively studied last decades. The main problem here is poor knowledge of physical characteristics of oil films, in particular, emulsified oil layers (EOL). The latter are ranged up to 70% of all pollutants. Physical characteristics of EOL which are responsible for wave damping and respectively for possibilities of their remote sensing depend on conditions of emulsification processes, e.g., mixing due to wave breaking, on percentage of water in the oil, etc. and are not well studied by now. In this paper results of laboratory studies of damping of gravity-capillary waves due to EOL on water are presented and compared to oil layers (OL). A laboratory method used previously for monomolecular films and OL, and based on measuring the damping coefficient and wavelength of parametrically generated standing waves has been applied for determination of EOL characteristics. Investigations of characteristics of crude oil, oil emulsions and crude OL and EOL have been carried out in a wide range of surface wave frequencies (from 10 to 25 Hz) and OL and EOL film thickness (from hundredths of millimeter to a few millimeters. The selected frequency range corresponds to Bragg waves for microwave, X- to Ka-band radars typically used for ocean remote sensing. An effect of enhanced wave damping due to EOL compared to non emulsified crude OL is revealed.

Accessible reactive surface area and abiotic redox reactivity of iron oxyhydroxides in acidic brines

Science.gov (United States)

Strehlau, Jennifer H.; Toner, Brandy M.; Arnold, William A.; Penn, R. Lee

2017-01-01

The reactivity of iron oxyhydroxide nanoparticles in low pH and high ionic strength solutions was quantified to assess abiotic contributions to oxidation-reduction chemistry in acidic brine environments, such as mine groundwater seepage, lakes in Western Australia, and acid mine drainage settings, which are of global interest for their environmental impacts and unique geomicrobiology. Factors expected to influence accessible and reactive surface area, including Fe(II) adsorption and aggregate size, were measured as a function of pH and CaCl2 concentration and related to the kinetics of redox reactions in aqueous suspensions of synthetic goethite (α-FeOOH), akaganeite (β-FeOOH), and ferrihydrite (Fe10O14(OH)2) nanoparticles. Aqueous conditions and iron oxyhydroxides were chosen based on characterization of natural iron-rich mine microbial mats located in Soudan Underground Mine State Park, Minnesota, USA. Quinone species were used as redox sensors because they are well-defined probes and are present in natural organic matter. Fe(II) adsorption to the iron oxyhydroxide mineral surfaces from aqueous solution was measurable only at pH values above 4 and either decreased or was not affected by CaCl2 concentration. Concentrations at or above 0.020 M CaCl2 in acetate buffer (pH 4.5) induced particle aggregation. Assessment of Fe(II) adsorption and particle aggregation in acidic brine suggested that accessible reactive surface area may be limited in acidic brines. This was supported by observations of decreasing benzoquinone reduction rate by adsorbed Fe(II) at high CaCl2 concentration. In contrast, the hydroquinone oxidation rate increased at high CaCl2 concentrations, which may be due to suppressed adsorption of Fe(II) generated by the reaction. Results suggest that iron geochemical cycling in acidic brine environments will be substantially different than for iron oxyhydroxides in low-saline waters with circumneutral pH. These findings have implications for acidic

Surface heat flow and lithosphere thermal structure of the larger Luxembourg area as a basis for the evaluation of its geothermal potential

Science.gov (United States)

Schintgen, Tom; Förster, Andrea

2014-05-01

The evaluation of the geothermal potential and the type of geothermal use necessitates knowledge of the subsurface temperature distribution in combination with hydraulic properties (e.g. porosity, permeability and hydraulic conductivity). In the larger Luxembourg area, only a few subsurface temperature data are available restricted to shallow depth. This paucity in data required to assess the thermal regime to drillable depths by modeling. The thermal model was constrained by surface heat flow and the lithosphere-asthenosphere boundary (LAB) characterized by the 1300° C isotherm. A surface heat-flow value of 75 ± 7 (2σ) mW m-2 was determined in central Luxembourg, which corroborates most values known from adjacent areas. The conceptual geological model for thermal modeling has a high resolution in the upper 15 km due to a wealth of geological data, while refraction seismic data and xenoliths provide petrological constraints for the lower part of the model down to the crust/mantle boundary. Thermal rock properties assigned to geological units are based on a large set of laboratory data, complemented by some literature data for the lower parts of the crust. The thermal structure is investigated by calculating 2-D steady-state thermal models along three crustal cross sections developed for the study area assuming a purely conductive lithosphere. The location of the LAB at 100 km depth, as typical for the Ardennes, provides the best fit with the measured surface heat flow of about 75 mW m-2. This LAB model provides temperatures at 5 km of 115-118° C on average and of about 600° C at the Moho. The resulting mantle heat flow in this model is 39-40 mW m-2. A reduced lithosphere thickness of 50 km as typical for the Eifel area to the east results in an increase of surface heat flow to 97 mW m-2 and of the mantle heat flow to 65 mW m-2, respectively. If heating from the Eifel plume had reached the surface yet, temperatures at 5 km would be about 20° C higher (and

A Three-Dimensional Enormous Surface Area Aluminum Microneedle Array with Nanoporous Structure

OpenAIRE

Chen, Po Chun; Hsieh, Sheng Jen; Chen, Chien Chon; Zou, Jun

2013-01-01

We proposed fabricating an aluminum microneedle array with a nanochannel structure on the surface by combining micromachining, electrolyte polishing, and anodization methods. The microneedle array provides a three-dimensional (3D) structure that possesses several hundred times more surface area than a traditional nanochannel template. Therefore, the microneedle array can potentially be used in many technology applications. This 3D microneedle array device can not only be used for painless inj...

Determination of the Presence of Three Antimicrobials in Surface Water Collected from Urban and Rural Areas

Directory of Open Access Journals (Sweden)

Alberto Cepeda

2013-02-01

Full Text Available Due to the continuous release of antimicrobials into the environment, the aim of this study was to compare the frequency of detection of sulfamethazine, sulfamethoxypyridazine and trimethoprim in surface water collected from urban and rural areas in Northwestern Spain. A monitoring study was conducted with 314 river water samples analyzed by high-performance liquid chromatography coupled to tandem mass spectrometry. The results indicated that 37% of the samples contained residues of at least one of the investigated antimicrobials, and every sampling site yielded positive samples. At sites located near the discharge points of wastewater treatment plants and near the collection point of a drinking-water treatment plant, more than 6% of the samples were positive for the presence of antimicrobial residues.

Long-term evolution of the surface environment of the Campine area, Northern Belgium

International Nuclear Information System (INIS)

Beerten, K.; De Craen, M.; Brassinnes, S.; Wouters, L.

2012-01-01

Document available in extended abstract form only. The Boom Clay in the Campine Basin is studied as the reference host formation for the geological disposal of radioactive waste. Near Mol, it is covered by approximately 200 m of sediment which protects the clay layer. Here, we will give a preliminary assessment of the long-term evolution of the surface environment in the Campine area for the next 1 Ma, with respect to geomorphological, pedological and hydrological processes. The current surface environment started to develop after the last major marine regression around 2 Ma ago. Then, the climatic and tectonic evolution caused significant changes in surficial geology, relief intensity, soils and hydrography. The palaeo-geographical evolution during the Quaternary is characterized by important stream divergences, relative uplift and erosion. Tectonic uplift of the Campine Plateau forced the river Meuse to incise into the substrate. To the west, erosional processes shaped the Nete and the Lower Scheldt basins as a result of combined uplift and gradual sea-level drop. The Campine Plateau being covered by coarse fluvial deposits from the Early and Middle Pleistocene, is largely protected from erosion. The same is true for the Campine Cuesta, that stands out as a result of the cohesive and erosion resistant Kempen Clay substrate. Burial graphs covering the last few million years from different locations in the Boom Clay sub-crop zone reflect processes of subsidence, uplift, sea level variations and climate change in relation to the erodibility of the substrate. Continuous burial during the Quaternary as a result of subsidence is observed near the Dutch border, and for the Roer Valley Graben. Burial graphs for the Campine Plateau do not show important erosional phases during the last several million years. This is due to the protecting cover of coarse fluvial deposits. The area that is now occupied by the Lower Scheldt and the Nete basin has experienced erosion during

Investigations of surface-tension effects due to small-scale complex boundaries

Science.gov (United States)

Feng, Jiansheng

In this Ph.D. dissertation, we have investigated some important surface-tension phenomena including capillarity, wetting, and wicking. We mainly focus on the geometric aspects of these problems, and to learn about how structures affect properties. . In the first project (Chapter 2), we used numerical simulations and experiments to study the meniscus of a fluid confined in capillaries with complicated cross-sectional geometries. In the simulations, we computed the three-dimensional shapes of the menisci formed in polygonal and star-shaped capillaries with sharp or rounded corners. Height variations across the menisci were used to quantify the effect of surface tension. Analytical solutions were derived for all the cases where the cross-sectional geometry was a regular polygon or a regular star-shape. Power indices that characterize the effects of corner rounding were extracted from simulation results. These findings can serve as guide for fabrications of unconventional three-dimensional structures in Capillary Force Lithography experiments. Experimental demonstrations of the working principle was also performed. Although quantitative matching between simulation and experimental results was not achieved due to the limitation of material properties, clear qualitative trends were observed and interesting three-dimensional nano-structures were produced. A second project (Chapter 3) focused on developing techniques to produce three-dimensional hierarchically structured superhydrophobic surfaces with high aspect ratios. We experimented with two different high-throughput electron-beam-lithography processes featuring single and dual electron-beam exposures. After a surface modification procedure with a hydrophobic silane, the structured surfaces exhibited two distinct superhydrophobic behaviors---high and low adhesion. While both types of superhydrophobic surfaces exhibited very high (approximately 160° water advancing contact angles, the water receding contact angles on

Mineral paragenesis on Mars: The roles of reactive surface area and diffusion.

Science.gov (United States)

Fairén, Alberto G; Gil-Lozano, Carolina; Uceda, Esther R; Losa-Adams, Elisabeth; Davila, Alfonso F; Gago-Duport, Luis

2017-09-01

Geochemical models of secondary mineral precipitation on Mars generally assume semiopen systems (open to the atmosphere but closed at the water-sediment interface) and equilibrium conditions. However, in natural multicomponent systems, the reactive surface area of primary minerals controls the dissolution rate and affects the precipitation sequences of secondary phases, and simultaneously, the transport of dissolved species may occur through the atmosphere-water and water-sediment interfaces. Here we present a suite of geochemical models designed to analyze the formation of secondary minerals in basaltic sediments on Mars, evaluating the role of (i) reactive surface areas and (ii) the transport of ions through a basalt sediment column. We consider fully open conditions, both to the atmosphere and to the sediment, and a kinetic approach for mineral dissolution and precipitation. Our models consider a geochemical scenario constituted by a basin (i.e., a shallow lake) where supersaturation is generated by evaporation/cooling and the starting point is a solution in equilibrium with basaltic sediments. Our results show that cation removal by diffusion, along with the input of atmospheric volatiles and the influence of the reactive surface area of primary minerals, plays a central role in the evolution of the secondary mineral sequences formed. We conclude that precipitation of evaporites finds more restrictions in basaltic sediments of small grain size than in basaltic sediments of greater grain size.

Relationship between surface area for adhesion and tensile bond strength--evaluation of a micro-tensile bond test.

Science.gov (United States)

Sano, H; Shono, T; Sonoda, H; Takatsu, T; Ciucchi, B; Carvalho, R; Pashley, D H

1994-07-01

The purpose of this study was to test the null hypothesis that there is no relationship between the bonded surface area of dentin and the tensile strength of adhesive materials. The enamel was removed from the occlusal surface of extracted human third molars, and the entire flat surface was covered with resin composite bonded to the dentin to form a flat resin composite crown. Twenty-four hours later, the bonded specimens were sectioned parallel to the long axis of the tooth into 10-20 thin sections whose upper part was composed of resin composite with the lower half being dentin. These small sections were trimmed using a high speed diamond bur into an hourglass shape with the narrowest portion at the bonded interface. Surface area was varied by altering the specimen thickness and width. Tensile bond strength was measured using custom-made grips in a universal testing machine. Tensile bond strength was inversely related to bonded surface area. At surface areas below 0.4 mm2, the tensile bond strengths were about 55 MPa for Clearfil Liner Bond 2 (Kuraray Co., Ltd.), 38 MPa for Scotchbond MP (3M Dental Products), and 20 MPa for Vitremer (3M Dental Products). At these small surface areas all of the bond failures were adhesive in nature. This new method permits measurement of high bond strengths without cohesive failure of dentin. It also permits multiple measurements to be made within a single tooth.

Differential loggerhead by-catch and direct mortality due to surface longlines according to boat strata and gear type

Directory of Open Access Journals (Sweden)

Juan A. Camiñas

2006-12-01

Full Text Available Surface longline gears are used to fish different species, mainly albacore Thunnus alalunga (Bonnaterre, 1788, bluefin tuna Thunnus thynnus (Linnaeus, 1758, and swordfish Xiphias gladius Linnaeus, 1758, and are considered highly dangerous for threatened marine turtles. Loggerheads Caretta caretta (Linnaeus, 1758 can be incidentally captured by surface longlines. A number of captured individuals die during the fishing operation, which we consider direct mortality due to fishing. We analysed the relative loggerhead by-catch and direct mortality associated with each type of boat and gear from April to December during the period 1999-2004 in the Spanish surface longline fleet that fishes in the western Mediterranean Sea, an important fishing area for this fleet. We used different indices to compute the catch per unit effort (CPUE according to the number of hooks and to the number of fishing operations for each type of boat and gear. Both by-catch and direct mortality differed significantly according to the type of boat and gear. With respect to the number of hooks, boats longer than 12 m not using a roller and targeting bluefin tuna captured the highest number of loggerheads, whereas boats longer than 12 m with a roller that targeted swordfish caused the highest direct mortality. With respect to the number of fishing operations, boats longer than 12 m without a roller that targeted albacore captured the highest number of loggerheads; the highest direct mortality was caused by this type of boat and by boats longer than 12 m using a roller and targeting swordfish.

Assessing the influence of groundwater and land surface scheme in the modelling of land surface-atmosphere feedbacks over the FIFE area in Kansas, USA

DEFF Research Database (Denmark)

Larsen, Morten Andreas Dahl; Højmark Rasmussen, Søren; Drews, Martin

2016-01-01

The land surface-atmosphere interaction is described differently in large scale surface schemes of regional climate models and small scale spatially distributed hydrological models. In particular, the hydrological models include the influence of shallow groundwater on evapotranspiration during dry...... by HIRHAM simulated precipitation. The last two simulations include iv) a standard HIRHAM simulation, and v) a fully coupled HIRHAM-MIKE SHE simulation locally replacing the land surface scheme by MIKE SHE for the FIFE area, while HIRHAM in standard configuration is used for the remaining model area...

Estimating Surface Area of Sponges and Marine Gorgonians as Indicators of Habitat Availability on Caribbean Coral Reefs

Science.gov (United States)

Surface area and topographical complexity are fundamental attributes of shallow tropical coral reefs and can be used to estimate habitat for fish and invertebrates. This study presents empirical methods for estimating surface area provided by sponges and gorgonians in the Central...

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

Science.gov (United States)

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.

Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations

Science.gov (United States)

Lamsal, Damodar; Fujita, Koji; Sakai, Akiko

2017-12-01

This study presents the geodetic mass balance of Kanchenjunga Glacier, one of the largest debris-covered glaciers in the easternmost Nepal Himalaya, which possesses a negative mass balance of -0.18 ± 0.17 m w.e. a-1 for the 1975-2010 study period, estimated using digital elevation models (DEMs) generated from Hexagon KH-9 and ALOS PRISM stereo images. Accurate DEMs, with a relative uncertainty of ±5.5 m, were generated from the intensive and manual editing of triangulated irregular network (TIN) models on a stereo MirrorTM/3D Monitor. The glacier ice-flow velocity field was also calculated using a feature-tracking method that was applied to two ALOS orthoimages taken in 2010. The elevation differences between the two DEMs highlight considerable surface lowering across the debris-covered area, and a slight thickening in the accumulation area of Kanchenjunga Glacier between 1975 and 2010. The magnitude and gradient of surface lowering are similar among the six glacier tributaries, even though they are situated at different elevations, which may reflect variations in the ice-flow velocity field. The pattern of surface lowering correlates well with the ice-flow velocity field over the debris-covered portion of the main tributary, suggesting that the glacier dynamics significantly affect surface lowering by altering the emergence velocity along the glacier, particularly in the compressive ablation area. Surface-lowering patterns partially correspond to the supraglacial pond area fraction of the glacier, with enhanced surface lowering observed in areas that possess a larger pond area fraction. These findings support the hypothesis that supraglacial ponds may intensify ice wastage and play a key role in the heterogeneous surface lowering of debris-covered glaciers. The estimated mass loss of Kanchenjunga Glacier is moderate compared with other debris-covered glaciers in neighboring Himalayan regions, which may be due to the lower pond area fraction of Kanchenjunga

Specific surface area of overlapping spheres in the presence of obstructions.

Science.gov (United States)

Jenkins, D R

2013-02-21

This study considers the random placement of uniform sized spheres, which may overlap, in the presence of another set of randomly placed (hard) spheres, which do not overlap. The overlapping spheres do not intersect the hard spheres. It is shown that the specific surface area of the collection of overlapping spheres is affected by the hard spheres, such that there is a minimum in the specific surface area as a function of the relative size of the two sets of spheres. The occurrence of the minimum is explained in terms of the break-up of pore connectivity. The configuration can be considered to be a simple model of the structure of a porous composite material. In particular, the overlapping particles represent voids while the hard particles represent fillers. Example materials are pervious concrete, metallurgical coke, ice cream, and polymer composites. We also show how the material properties of such composites are affected by the void structure.

Using GIS techniques for surface runoff potential analysis in the Subcarpathian area between Buzãu and Slãnic rivers, in Romania

Directory of Open Access Journals (Sweden)

IULIA FONTANINE

2013-08-01

Full Text Available The Subcarpathian area between Buzău and Slănic rivers, located in the south-eastern part of Romania, is one of the most affected areas by the torrential related phenomena. This occurs due to physical-geographical and economical-geographical factors, such as: slope, curvature profile, lithology, soil texture and land use. In order to calculate and spatially model the surface runoff potential index, these factors were integrated and worked in GIS enviroment. Each characteristic of the factors was given a bonitation score, according to the way that it influences surface runoff. By applying the methodology mainly taken after Smith (2003 [1], the Flash-Flood Potential Index was obtained, with values between 19.4 - 44.5. The highest values of the index correspond to deforestated slopes, which exceed 15º, located in Bălăneasa and Sărățel river basins.

A Remote Sensing Approach to Environmental Monitoring in a Reclaimed Mine Area

Directory of Open Access Journals (Sweden)

Rajchandar Padmanaban

2017-12-01

Full Text Available Mining for resources extraction may lead to geological and associated environmental changes due to ground movements, collision with mining cavities, and deformation of aquifers. Geological changes may continue in a reclaimed mine area, and the deformed aquifers may entail a breakdown of substrates and an increase in ground water tables, which may cause surface area inundation. Consequently, a reclaimed mine area may experience surface area collapse, i.e., subsidence, and degradation of vegetation productivity. Thus, monitoring short-term landscape dynamics in a reclaimed mine area may provide important information on the long-term geological and environmental impacts of mining activities. We studied landscape dynamics in Kirchheller Heide, Germany, which experienced extensive soil movement due to longwall mining without stowing, using Landsat imageries between 2013 and 2016. A Random Forest image classification technique was applied to analyze land-use and landcover dynamics, and the growth of wetland areas was assessed using a Spectral Mixture Analysis (SMA. We also analyzed the changes in vegetation productivity using a Normalized Difference Vegetation Index (NDVI. We observed a 19.9% growth of wetland area within four years, with 87.2% growth in the coverage of two major waterbodies in the reclaimed mine area. NDVI values indicate that the productivity of 66.5% of vegetation of the Kirchheller Heide was degraded due to changes in ground water tables and surface flooding. Our results inform environmental management and mining reclamation authorities about the subsidence spots and priority mitigation areas from land surface and vegetation degradation in Kirchheller Heide.

High-Surface-Area, Emulsion-Templated Carbon Foams by Activation of polyHIPEs Derived from Pickering Emulsions

Directory of Open Access Journals (Sweden)

Robert T. Woodward

2016-09-01

Full Text Available Carbon foams displaying hierarchical porosity and excellent surface areas of >1400 m2/g can be produced by the activation of macroporous poly(divinylbenzene. Poly(divinylbenzene was synthesized from the polymerization of the continuous, but minority, phase of a simple high internal phase Pickering emulsion. By the addition of KOH, chemical activation of the materials is induced during carbonization, producing Pickering-emulsion-templated carbon foams, or carboHIPEs, with tailorable macropore diameters and surface areas almost triple that of those previously reported. The retention of the customizable, macroporous open-cell structure of the poly(divinylbenzene precursor and the production of a large degree of microporosity during activation leads to tailorable carboHIPEs with excellent surface areas.

Study of LiFePO{sub 4} cathode materials coated with high surface area carbon

Energy Technology Data Exchange (ETDEWEB)

Lu, Cheng-Zhang; Fey, George Ting-Kuo [Department of Chemical and Materials Engineering, National Central University, Chung-Li 32054 (China); Kao, Hsien-Ming [Department of Chemistry, National Central University, Chung-Li 32054 (China)

2009-04-01

LiFePO{sub 4} is a potential cathode material for 4 V lithium-ion batteries. Carbon-coated lithium iron phosphates were prepared using a high surface area carbon to react precursors through a solid-state process, during which LiFePO{sub 4} particles were embedded in amorphous carbon. The carbonaceous materials were synthesized by the pyrolysis of peanut shells under argon, where they were carbonized in a two-step process that occurred between 573 and 873 K. The shells were also treated with a proprietary porogenic agent with the goal of altering the pore structure and surface area of the pyrolysis products. The electrochemical properties of the as-prepared LiFePO{sub 4}/C composite cathode materials were systematically characterized by X-ray diffraction, scanning electron microscope, element mapping, energy dispersive spectroscopy, Raman spectroscopy, and total organic carbon (TOC) analysis. In LiFePO{sub 4}/C composites, the carbon not only increases rate capability, but also stabilizes capacity. In fact, the capacity of the composites increased with the specific surface area of carbon. The best result was observed with a composite made of 8.0 wt.% with a specific surface area of 2099 m{sup 2} g{sup -1}. When high surface area carbon was used as a carbon source to produce LiFePO{sub 4}, overall conductivity increased from 10{sup -8} to 10{sup -4} S cm{sup -1}, because the inhibition of particle growth during the final sintering process led to greater specific capacity, improved cycling properties and better rate capability compared to a pure olivine LiFePO{sub 4} material. (author)

Effect of high surface area activated carbon on thermal degradation of jet fuel

Energy Technology Data Exchange (ETDEWEB)

Gergova, K.; Eser, S.; Arumugam, R.; Schobert, H.H. [Pennsylvania State Univ., University Park, PA (United States)

1995-05-01

Different solid carbons added to jet fuel during thermal stressing cause substantial changes in pyrolytic degradation reactions. Activated carbons, especially high surface area activated carbons were found to be very effective in suppressing solid deposition on metal reactor walls during stressing at high temperatures (425 and 450{degrees}C). The high surface area activated carbon PX-21 prevented solid deposition on reactor walls even after 5h at 450{degrees}C. The differences seen in the liquid product composition when activated carbon is added indicated that the carbon surfaces affect the degradation reactions. Thermal stressing experiments were carried out on commercial petroleum-derived JPTS jet fuel. We also used n-octane and n-dodecane as model compounds in order to simplify the study of the chemical changes which take place upon activated carbon addition. In separate experiments, the presence of a hydrogen donor, decalin, together with PX-21 was also studied.

Mesoporous TiO{sub 2} aggregate photoanode with high specific surface area and strong light scattering for dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Li, Chunhui; Luo, Yanhong; Guo, Xiaozhi; Li, Dongmei [Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Mi, Jianli; So, Lasse; Hald, Peter [Center for Materials Crystallography, Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, DK-8000 Aarhus (Denmark); Meng, Qingbo, E-mail: qbmeng@iphy.ac.cn [Key Laboratory for Renewable Energy, Chinese Academy of Sciences, Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Iversen, Bo B., E-mail: bo@chem.au.dk [Center for Materials Crystallography, Department of Chemistry and Interdisciplinary Nanoscience Center, Aarhus University, DK-8000 Aarhus (Denmark)

2012-12-15

Phase-pure anatase TiO{sub 2} nanocrystallite aggregates synthesized by a continuous supercritical fluid process have been first used for fabricating mesoporous photoanodes of dye-sensitized solar cells (DSCs). Due to the small size (11 nm) of the TiO{sub 2} nanocrystallites in the aggregates, the mesoporous photoanode provides a high specific surface area, 80 m{sup 2}/g, which ensures high dye loading. At the same time, the submicrometer-sized aggregates endow the mesoporous photoanode with strong light scattering effect. Therefore, the light harvesting efficiency of the photoanode is increased. With an improved short-circuit current density, a high overall power conversion efficiency of 8.65% (100 mW/cm{sup 2}, AM 1.5) is achieved without additional scattering layers, 12% enhanced compared with the DSCs fabricated from commercial Degussa P25 with exactly the same procedures. In addition, this supercritical fluid process is scalable and rapid (less than one minute) for TiO{sub 2} aggregates synthesis, which will push the commercialization of DSCs in the future. - Graphical abstract: Due to the special morphology and structure, the photoanode of DSCs provides high specific surface area and strong light scattering at the same time, which results in high conversion efficiencies of the DSCs. Table of contents: Thanks to the synchronous realization of high specific surface area and strong light scattering, a high efficiency of 8.65% was achieved based on a novel mesoporous TiO{sub 2} aggregates photoanode for DSCs. Highlights: Black-Right-Pointing-Pointer The TiO{sub 2} aggregate photoanode provides a possible route for highly efficient DSCs. Black-Right-Pointing-Pointer Photoanode with high dye loading and light scattering is successfully fabricated. Black-Right-Pointing-Pointer TiO{sub 2} synthesized by a supercritical fluid process is first applied to DSCs. Black-Right-Pointing-Pointer The synthesis method and high efficiency will push the commercialization of DSCs.

Negative plate macropore surfaces in lead-acid batteries: Porosity, Brunauer-Emmett-Teller area, and capacity

Energy Technology Data Exchange (ETDEWEB)

D' Alkaine, C.V.; de O. Brito, G.A. [Group of Electrochemistry and Polymers, DQ-UFSCar, Rodovia Washington Luis, Km 235, CP 676, 13565-905 Sao Carlos (SP) (Brazil)

2009-06-01

We propose an explanation for the production of an electrochemically active area during the electrochemical formation of lead-acid battery negative plates based on solid-state reactions. Our proposal is supported by experimental data. This study includes a critical review of the literature on charge/discharge mechanisms, porosity, and BET area. The critical review, through the latter two parameters, indicates the existence of both macro and micropores in positive plates, but only macropores in negative plates, with characteristic surface roughness. In the present paper the surface sulfation of the precursor is controlled using various acidic, neutral and alkaline solutions during an electrochemical formation process that does not include soaking. Our results confirm that variable roughness can be produced at the negative plate macropore surfaces. The morphological changes produced by different formation conditions are assessed by measuring the macroporosity, BET area, and capacity of single negative plates. Based on these concepts, a method was developed and applied to measure independently the contributions of geometrical surface macroporosity and roughness to the negative plate capacity. (author)

Areas of ground subsidence due to geofluid withdrawal

Energy Technology Data Exchange (ETDEWEB)

Grimsrud, G.P.; Turner, B.L.; Frame, P.A.

1978-08-01

Detailed information is provided on four geothermal areas with histories of subsidence. These were selected on the basis of: physical relevance of subsidence areas to high priority US geothermal sites in terms of withdrawn geofluid type, reservoir depth, reservoir geology and rock characteristics, and overburden characteristics; and data completeness, quality, and availability. The four areas are: Chocolate Bayou, Raft River Valley, Wairakei, and the Geysers. (MHR)

Large area smoothing of surfaces by ion bombardment: fundamentals and applications

International Nuclear Information System (INIS)

Frost, F; Fechner, R; Ziberi, B; Voellner, J; Flamm, D; Schindler, A

2009-01-01

Ion beam erosion can be used as a process for achieving surface smoothing at microscopic length scales and for the preparation of ultrasmooth surfaces, as an alternative to nanostructuring of various surfaces via self-organization. This requires that in the evolution of the surface topography different relaxation mechanisms dominate over the roughening, and smoothing of initially rough surfaces can occur. This contribution focuses on the basic mechanisms as well as potential applications of surface smoothing using low energy ion beams. In the first part, the fundamentals for the smoothing of III/V semiconductors, Si and quartz glass surfaces using low energy ion beams (ion energy: ≤2000 eV) are reviewed using examples. The topography evolution of these surfaces with respect to different process parameters (ion energy, ion incidence angle, erosion time, sample rotation) has been investigated. On the basis of the time evolution of different roughness parameters, the relevant surface relaxation mechanisms responsible for surface smoothing are discussed. In this context, physical constraints as regards the effectiveness of surface smoothing by direct ion bombardment will also be addressed and furthermore ion beam assisted smoothing techniques are introduced. In the second application-orientated part, recent technological developments related to ion beam assisted smoothing of optically relevant surfaces are summarized. It will be demonstrated that smoothing by direct ion bombardment in combination with the use of sacrificial smoothing layers and the utilization of appropriate broad beam ion sources enables the polishing of various technologically important surfaces down to 0.1 nm root mean square roughness level, showing great promise for large area surface processing. Specific examples are given for ion beam smoothing of different optical surfaces, especially for substrates used for advanced optical applications (e.g., in x-ray optics and components for extreme

Comparison of deposited surface area of airborne ultrafine particles generated from two welding processes.

Science.gov (United States)

Gomes, J F; Albuquerque, P C; Miranda, Rosa M; Santos, Telmo G; Vieira, M T

2012-09-01

This article describes work performed on the assessment of the levels of airborne ultrafine particles emitted in two welding processes metal-active gas (MAG) of carbon steel and friction-stir welding (FSW) of aluminium in terms of deposited area in alveolar tract of the lung using a nanoparticle surface area monitor analyser. The obtained results showed the dependence from process parameters on emitted ultrafine particles and clearly demonstrated the presence of ultrafine particles, when compared with background levels. The obtained results showed that the process that results on the lower levels of alveolar-deposited surface area is FSW, unlike MAG. Nevertheless, all the tested processes resulted in important doses of ultrafine particles that are to be deposited in the human lung of exposed workers.

Frequency hopping due to acousto-electric interaction in ZnO based surface acoustic wave oscillator

Science.gov (United States)

Dasgupta, Daipayan; Sreenivas, K.

2011-08-01

A 36 MHz surface acoustic wave delay line based oscillator has been used to study the effect of acousto-electric interaction due to photo generated charge carriers in rf sputtered ZnO film under UV illumination (λ = 365 nm, 20-100 μW/cm2). Design aspects for developing a delay line based SAW oscillator are specified. The observed linear downshift in frequency (2.2 to 19.0 kHz) with varying UV intensity (20-100 μW/cm2) is related to the fractional velocity change due to acousto-electric interaction. UV illumination level of 100 μW/cm2 leads to a characteristic frequency hopping behavior arising due to a change in the oscillation criteria, and is attributed to the complex interplay between the increased attenuation and velocity shift.

Synthesis of porous carbon/silica nanostructured microfiber with ultrahigh surface area

Energy Technology Data Exchange (ETDEWEB)

Zhou, Dan; Dong, Yan; Cui, Liru; Lin, Huiming, E-mail: hiuminglin@gmail.com; Qu, Fengyu, E-mail: qufengyu2012@yahoo.cn, E-mail: qufengyu@hrbnu.edu.cn [Harbin Normal University, College of Chemistry and Chemical Engineering (China)

2014-12-15

Carbon/silica-nanostructured microfibers were synthesized via electrospinning method using phenol-formaldehyde resin and tetraethyl orthosilicate as carbon and silica precursor with triblock copolymer Pluronic P123 as soft template. The prepared samples show uniform microfiber structure with ∼1 μm in diameter and dozens of microns in length. Additionally, the mesopores in the material is about 2–6 nm. When the silica component was removed by HF, the porous carbon microfibers (PCMFs) were obtained. In addition, after the carbon/silica composites were calcined in air, the porous silica microfibers (PSiMFs) were obtained, revealing the converse porous nanostructure as PCMFs. It is a simple way to prepare PCMFs and PSiMFs with silica and carbon as the template to each other. Additionally, PCMFs possess an ultrahigh specific surface area (2,092 m{sup 2} g{sup −1}) and large pore volume. The electrochemical performance of the prepared PCMF material was investigated in 6.0 M KOH electrolyte. The PCMF electrode exhibits a high specific capacitance (252 F g{sup −1} at 0.5 A g{sup −1}). Then, superior cycling stability (97 % retention after 4,000 cycles) mainly is due to its unique nanostructure.

Impact of microstructure evolution on the difference between geometric and reactive surface areas in natural chalk

Science.gov (United States)

Yang, Y.; Bruns, S.; Stipp, S. L. S.; Sørensen, H. O.

2018-05-01

The coupling between flow and mineral dissolution drives the evolution of many natural and engineered flow systems. Pore surface changes as microstructure evolves but this transient behaviour has traditionally been difficult to model. We combined a reactor network model with experimental, greyscale tomography data to establish the morphological grounds for differences among geometric, reactive and apparent surface areas in dissolving chalk. This approach allowed us to study the effects of initial geometry and macroscopic flow rate independently. The simulations showed that geometric surface, which represents a form of local transport heterogeneity, increases in an imposed flow field, even when the porous structure is chemically homogeneous. Hence, the fluid-reaction coupling leads to solid channelisation, which further results in fluid focusing and an increase in geometric surface area. Fluid focusing decreases the area of reactive surface and the residence time of reactant, both contribute to the over-normalisation of reaction rate. In addition, the growing and merging of microchannels, near the fluid entrance, contribute to the macroscopic, fast initial dissolution rate of rocks.

Methodology for estimation of time-dependent surface heat flux due to cryogen spray cooling.

Science.gov (United States)

Tunnell, James W; Torres, Jorge H; Anvari, Bahman

2002-01-01

Cryogen spray cooling (CSC) is an effective technique to protect the epidermis during cutaneous laser therapies. Spraying a cryogen onto the skin surface creates a time-varying heat flux, effectively cooling the skin during and following the cryogen spurt. In previous studies mathematical models were developed to predict the human skin temperature profiles during the cryogen spraying time. However, no studies have accounted for the additional cooling due to residual cryogen left on the skin surface following the spurt termination. We formulate and solve an inverse heat conduction (IHC) problem to predict the time-varying surface heat flux both during and following a cryogen spurt. The IHC formulation uses measured temperature profiles from within a medium to estimate the surface heat flux. We implement a one-dimensional sequential function specification method (SFSM) to estimate the surface heat flux from internal temperatures measured within an in vitro model in response to a cryogen spurt. Solution accuracy and experimental errors are examined using simulated temperature data. Heat flux following spurt termination appears substantial; however, it is less than that during the spraying time. The estimated time-varying heat flux can subsequently be used in forward heat conduction models to estimate temperature profiles in skin during and following a cryogen spurt and predict appropriate timing for onset of the laser pulse.

Albedo and land surface temperature shift in hydrocarbon seepage potential area, case study in Miri Sarawak Malaysia

International Nuclear Information System (INIS)

Suherman, A; Rahman, M Z A; Busu, I

2014-01-01

The presence of hydrocarbon seepage is generally associated with rock or mineral alteration product exposures, and changes of soil properties which manifest with bare development and stress vegetation. This alters the surface thermodynamic properties, changes the energy balance related to the surface reflection, absorption and emission, and leads to shift in albedo and LST. Those phenomena may provide a guide for seepage detection which can be recognized inexpensively by remote sensing method. District of Miri is used for study area. Available topographic maps of Miri and LANDSAT ETM+ were used for boundary construction and determination albedo and LST. Three land use classification methods, namely fixed, supervised and NDVI base classifications were employed for this study. By the intensive land use classification and corresponding statistical comparison was found a clearly shift on albedo and land surface temperature between internal and external seepage potential area. The shift shows a regular pattern related to vegetation density or NDVI value. In the low vegetation density or low NDVI value, albedo of internal area turned to lower value than external area. Conversely in the high vegetation density or high NDVI value, albedo of internal area turned to higher value than external area. Land surface temperature of internal seepage potential was generally shifted to higher value than external area in all of land use classes. In dense vegetation area tend to shift the temperature more than poor vegetation area

Albedo and land surface temperature shift in hydrocarbon seepage potential area, case study in Miri Sarawak Malaysia

Science.gov (United States)

Suherman, A.; Rahman, M. Z. A.; Busu, I.

2014-02-01

The presence of hydrocarbon seepage is generally associated with rock or mineral alteration product exposures, and changes of soil properties which manifest with bare development and stress vegetation. This alters the surface thermodynamic properties, changes the energy balance related to the surface reflection, absorption and emission, and leads to shift in albedo and LST. Those phenomena may provide a guide for seepage detection which can be recognized inexpensively by remote sensing method. District of Miri is used for study area. Available topographic maps of Miri and LANDSAT ETM+ were used for boundary construction and determination albedo and LST. Three land use classification methods, namely fixed, supervised and NDVI base classifications were employed for this study. By the intensive land use classification and corresponding statistical comparison was found a clearly shift on albedo and land surface temperature between internal and external seepage potential area. The shift shows a regular pattern related to vegetation density or NDVI value. In the low vegetation density or low NDVI value, albedo of internal area turned to lower value than external area. Conversely in the high vegetation density or high NDVI value, albedo of internal area turned to higher value than external area. Land surface temperature of internal seepage potential was generally shifted to higher value than external area in all of land use classes. In dense vegetation area tend to shift the temperature more than poor vegetation area.

n-Alkylamine-assisted preparation of a high surface area vanadyl phosphate/tetraethylorthosilicate nanocomposite

Energy Technology Data Exchange (ETDEWEB)

Ferreira, João Paulo L., E-mail: billbrujah@yahoo.com.br [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14040-901 (Brazil); Zampronio, Elaine C.; Oliveira, Herenilton P. [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto, SP 14040-901 (Brazil)

2013-02-15

Graphical abstract: CuK{sub α} X-ray diffraction patterns of the VP, VPOc, VPOcT, VPOcT200 and VPOcT500. Highlights: ► TEOS and octylamine incorporation into the VP was achieved by expanding the lamellar. ► The specific surface area increased from 15 m{sup 2} g{sup −1} in VP to 237 m{sup 2} g{sup −1} in VPOcT. ► The VPOcT exhibited thermal resistance up to 200 °C in air. ► Upon thermal treatment up to 500 °C, the surface area increased to 838 m{sup 2} g{sup −1}. -- Abstract: We have developed a vanadyl phosphate/tetraethylorthosilicate (VPO/TEOS) nanocomposite comprised of silicate chains interleaved with VPO layers, prepared by using an n-alkylamines such as octylamine as the structure directing agent. The nanocomposites were synthesized by reacting amine-intercalated vanadyl phosphate with tetraethylorthosilicate via the soft chemistry approach. The synthetic procedure encompassed the exfoliation of the layered vanadyl phosphate as well as the reorganization of this exfoliated solid into a mesostructured lamellar phase with the same V–P–O connectivity as in the original matrix. TEOS incorporation into the vanadyl phosphate was achieved by expanding the lamellar structure with n-alkylamine (Δd = 13 Å with n-octylamine). The specific surface area increased from 15 m{sup 2} g{sup −1} in the vanadyl phosphate matrix to 237 m{sup 2} g{sup −1} in VPOcT, and the isotherm curves revealed the characteristic hysteresis of mesoporous materials. Upon thermal treatment up to 500 °C, the surface area increased to 837 m{sup 2} g{sup −1}, which is suitable for catalytic purposes.

Surface deformation monitoring of Sinabung volcano using multi temporal InSAR method and GIS analysis for affected area assessment

Science.gov (United States)

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.

[Distribution, surface and protected area of palm-swamps in Costa Rica and Nicaragua].

Science.gov (United States)

Serrano-Sandí, Juan; Bonilla-Murillo, Fabian; Sasa, Mahmood

2013-09-01

In Central America, palm swamps are known collectively as yolillales. These wetlands are usually dominated by the raffia palm Raphia taedigera, but also by the royal palm Manicaria saccifera and -in lower extensions- by the American oil palm Elaeis oleifera. The yolillales tend to be poor in woody species and are characteristic of regions with high rainfall and extensive hydroperiods, so they remain flooded most of the year. The dominance of large raffia palm leaves in the canopy, allow these environments to be distinguishable in aerial photographs, which consequently has helped to map them along most of their distribution. However, while maps depicting yolillales are available, the extent of their surface area, perimeter and connectivity remains poorly understood. This is particularly true for yolillales in Costa Rica and Nicaragua, countries that share a good proportion of palm dominated swaps in the Rio San Juan Basin. In addition, it is not known the actual area of these environments that is under any category of protection according to the conservation systems of both countries. As a first step to catalog yolillal wetlands in Costa Rica and Nicaragua, this paper evaluates cartographic maps to delineate yolillales in the region. A subsample of yolillales mapped in this study were visited and we geo-referenced them and evaluate the extent and condition of the swamp. A total of 110 883.2ha are classified as yolillales in Nicaragua, equivalent to 22% of wetland surface area recorded for that country (excluding the Cocibolca and Xolothn Lakes). In Costa Rica, 53 931.3ha are covered by these palm dominated swamps, which represent 16.24% of the total surface area covered by wetlands. About 47% of the area covered by yolillales in Nicaragua is under some category of protection, the largest extensions protected by Cerro Silva, Laguna Tale Sulumas and Indio Maiz Nature Reserves. In Costa Rica, 55.5% of the area covered by yolillal is located within protected areas

Developing Open-Ended Questions for Surface Area and Volume of Beam

Science.gov (United States)

Kurniawan, Henry; Putri, Ratu Ilma Indra; Hartono, Yusuf

2018-01-01

The purpose of this research was to show open-ended questions about surface area and beam volume which valid and practice, have potential effect. This research is research development which consists of two main phases: preliminary phase (preparation phase and problem design) and formative evaluation phase (evaluation and revision phases). The…

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

Science.gov (United States)

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.

VEGETATION COVERAGE AND IMPERVIOUS SURFACE AREA ESTIMATED BASED ON THE ESTARFM MODEL AND REMOTE SENSING MONITORING

Directory of Open Access Journals (Sweden)

R. Hu

2018-04-01

Full Text Available 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.

Transient thermal stresses in an orthotropic finite rectangular plate due to arbitrary surface heat-generations

International Nuclear Information System (INIS)

Sugano, Y.

1980-01-01

The transient thermal stresses in an orthotropic finite rectangular plate due to arbitrary surface heat-generations on two edges are studied by means of the Airy stress function. The purposes of this paper are to present a method of determing the transient thermal stresses in an orthographic rectangular plate with four edges of distinct thermal boundary condition of the third kind which exactly satisfy the traction-free conditions of shear stress over all boundaries including four corners of the plate, and to consider the effects of the anisotropies of material properties and the convective heat transfer on the upper and lower surfaces on the thermal stress distribution. (orig.)

Dependence of the specific surface area of the nuclear fuel with the matrix oxidation

International Nuclear Information System (INIS)

Gomez, F.; Quinones, J.; Iglesias, E.; Rodriguez, N.

2008-01-01

This paper is focused on the study of the changes in the specific surface area measured using BET techniques. The objective is to obtain a relation between this parameter and the change in the matrix stoichiometry (i.e., oxidation increase). None of the actual models used for extrapolating the behaviour of the spent fuel matrix under repository conditions have included this dependence yet. In this work the specific surface area of different uranium oxide were measured using N 2 (g) and Kr(g). The starting material was UO 2+x (s) with a size powder distribution lower than 20 μm. The results included in this paper shown a strong dependence on specific surface area with the matrix stoichiometry, i.e., and increase of more than one order of magnitude (SUO 2 = 6 m 2 *g -1 and SU 3 O 8 = 16.07 m 2 *g -1 ). Furthermore, the particle size distribution measured as a function of the thermal treatment done shows changes on the powder size related to the changes observed in the uranium oxide stoichiometry. (authors)

Interaction between surface water areas and groundwater in Hanoi city, Viet Nam

Science.gov (United States)

Hayashi, T.; Kuroda, K.; Do Thuan, A.; Tran Thi Viet, N.; Takizawa, S.

2012-12-01

Hanoi is the capital of Viet Nam and the second largest city in this country (population: 6.45 million in 2009). Hanoi city has developed along the Red River and has many lakes, ponds and canals. However, recent rapid urbanization of this city has reduced number of natural water areas such as ponds and lakes by reclamation not only in the central area but the suburban area. Canals also have been reclaimed or cut into pieces. Contrary, number of artificial water areas such as fish cultivation pond has rapidly increased. On the other hand, various kind of waste water flows into these natural and artificial water areas and induces pollution and eutrophication. These waste waters also have possibility of pollution of groundwater that is one of major water resources in this city. In addition, groundwater in this area has high concentrations of Arsenic, Fe and NH4. Thus, groundwater use may causes re-circulation of Arsenic. However, studies on the interaction between surface water areas and groundwater and on the role of surface water areas for solute transport with water cycle are a few. Therefore, we focused on these points and took water samples of river, pond and groundwater from four communities in suburban areas: two communities are located near the Red River and other two are far from the River. Also, columnar sediment samples of these ponds were taken and pore water was abstracted. Major dissolved ions, metals and stable isotopes of oxygen and hydrogen of water samples were analyzed. As for water cycle, from the correlation between δ18O and δD, the Red River water (after GNIR) were distributed along the LMWL (δD=8.2δ18O+14.1, calculated from precipitation (after GNIP)). On the other hand, although the pond waters in rainy season were distributed along the LMWL, that in dry season were distributed along the local evaporation line (LEL, slope=5.6). The LEL crossed with the LMWL at around the point of weighted mean values of precipitation in rainy season and of

Characterization of chemical composition, surface area pore, and thermal properties of zeolites from Bayah, Tasikmalaya, and Lampung

International Nuclear Information System (INIS)

Ginting, Aslina Br.; Dian Anggraini; Sutri Indaryati; Rosika Kriswarini

2007-01-01

Characterization of chemical composition, surface area, pore radius, adsorption, and thermal properties of zeolites from Bayah, Tasikmalaya, and Lampung have been performed. The purpose of the characterization is to understand the characteristics of the three zeolites since different types of zeolite will yield different chemical composition, surface area, pore radius, and adsorption. The analysis shows that zeolites from Bayah, Tasikmalaya, and Lampung consist of chemical elements Al, Si, P, K, Ca, Ti, Fe, and S. The analysis of the surface area indicates that zeolite from Lampung has surface area of 10.0477 m 2 , pore radius of 16.0653 Å, and adsorption of 24.500 ml/g, which are greater than those of zeolite from Tasikmalaya with surface area of 6.3319 m2, pore radius of 16.2350 Å, adsorption of 13.2500 ml/g, zeolite from Bayah with surface area of 8.3528 m2, pore radius of 16.2350 Å, and adsorption of 13.250 ml/g. From of the thermal properties characterization it is shown the three zeolites experienced weight reduction from 5.93% to 8.33%, which results in the formation of new phases as indicated by endothermic reactions from 150 °C to 600 °C and from 850 °C to 1000 °C. The three zeolites experienced a decrease in heat capacity up to temperature of 199.96 °C, whereas at temperatures above 216.66 °C the zeolites experienced an increase in heat capacity up to 437.78 °C. The results of the characterization indicate that different types of zeolite do not yield significant difference in chemical composition and thermal characteristics as proven with F test, however different surface area, pore radius, and adsorption characteristics are observed. The characterization results are expected to be the first step in determining the characteristics of the three zeolites that are to be used for cesium ion exchange in the incoming research. (author)

High surface area microporous activated carbons prepared from Fox nut (Euryale ferox) shell by zinc chloride activation

Energy Technology Data Exchange (ETDEWEB)

Kumar, Arvind; Mohan Jena, Hara, E-mail: hmjena@nitrkl.ac.in

2015-11-30

Graphical abstract: - Highlights: • Activated carbons have been prepared from Fox nutshell with chemical activation using ZnCl{sub 2}. • The thermal behavior of the raw material and impregnated raw material has been carried out by thermogravimetric analysis. • The characterizations of the prepared activated carbons have been determined by nitrogen adsorption–desorption isotherms, FTIR, XRD, and FESEM. • The BET surface area and total pore volume of prepared activated carbon has been obtained as 2869 m{sup 2}/g, 2124 m{sup 2}/g, and 1.96 cm{sup 3}/g, respectively. • The microporous surface area, micropore volume, and microporosity percentage of prepared activated carbon has been obtained as 2124 m{sup 2}/g, 1.68 cm{sup 3}/g, and 85.71%, respectively. - Abstract: High surface area microporous activated carbon has been prepared from Fox nutshell (Euryale ferox) by chemical activation with ZnCl{sub 2} as an activator. The process has been conducted at different impregnation (ZnCl{sub 2}/Fox nutshell) ratios (1–2.5) and carbonization temperatures (500–700 °C). The thermal decomposition behavior of Fox nutshell and impregnated Fox nutshell has been carried out by thermogravimetric analysis. The pore properties including the BET surface area, micropore surface area, micropore volume, and pore size distribution of the activated carbons have been determined by nitrogen adsorption–desorption isotherms at −196 °C using the BET, t-plot method, DR, and BJH methods. The BET surface area, the microporous surface area, total pore volume, and micropore volume have been obtained as 2869 m{sup 2}/g, 2124 m{sup 2}/g, 1.96 cm{sup 3}/g, and 1.68 cm{sup 3}/g, respectively, and the microporosity percentage of the prepared activated carbon is 85.71%. The prepared activated carbons have been also characterized with instrumental methods such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM).

High surface area microporous activated carbons prepared from Fox nut (Euryale ferox) shell by zinc chloride activation

International Nuclear Information System (INIS)

Kumar, Arvind; Mohan Jena, Hara

2015-01-01

Graphical abstract: - Highlights: • Activated carbons have been prepared from Fox nutshell with chemical activation using ZnCl 2 . • The thermal behavior of the raw material and impregnated raw material has been carried out by thermogravimetric analysis. • The characterizations of the prepared activated carbons have been determined by nitrogen adsorption–desorption isotherms, FTIR, XRD, and FESEM. • The BET surface area and total pore volume of prepared activated carbon has been obtained as 2869 m 2 /g, 2124 m 2 /g, and 1.96 cm 3 /g, respectively. • The microporous surface area, micropore volume, and microporosity percentage of prepared activated carbon has been obtained as 2124 m 2 /g, 1.68 cm 3 /g, and 85.71%, respectively. - Abstract: High surface area microporous activated carbon has been prepared from Fox nutshell (Euryale ferox) by chemical activation with ZnCl 2 as an activator. The process has been conducted at different impregnation (ZnCl 2 /Fox nutshell) ratios (1–2.5) and carbonization temperatures (500–700 °C). The thermal decomposition behavior of Fox nutshell and impregnated Fox nutshell has been carried out by thermogravimetric analysis. The pore properties including the BET surface area, micropore surface area, micropore volume, and pore size distribution of the activated carbons have been determined by nitrogen adsorption–desorption isotherms at −196 °C using the BET, t-plot method, DR, and BJH methods. The BET surface area, the microporous surface area, total pore volume, and micropore volume have been obtained as 2869 m 2 /g, 2124 m 2 /g, 1.96 cm 3 /g, and 1.68 cm 3 /g, respectively, and the microporosity percentage of the prepared activated carbon is 85.71%. The prepared activated carbons have been also characterized with instrumental methods such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM).

Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

NARCIS (Netherlands)

Machguth, Horst; Thomsen, Henrik H.; Weidick, Anker; Ahlstrøm, Andreas P.; Abermann, Jakob; Andersen, Morten L.; Andersen, Signe B.; Bjørk, Anders A.; Box, Jason E.; Braithwaite, Roger J.; Bøggild, Carl E.; Citterio, Michele; Clement, Poul; Colgan, William; Fausto, Robert S.; Gleie, Karin; Gubler, Stefanie; Hasholt, Bent; Hynek, Bernhard; Knudsen, Niels T.; Larsen, Signe H.; Mernild, Sebastian H.; Oerlemans, Johannes; Oerter, Hans; Olesen, Ole B.; Smeets, C. J P Paul; Steffen, Konrad; Stober, Manfred; Sugiyama, Shin; Van As, Dirk; Van Den Broeke, Michiel R.; Van De Wal, Roderik S W

2016-01-01

Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in

Compaction of PDMS due to proton beam irradiation

International Nuclear Information System (INIS)

Szilasi, S.Z.; Huszank, R.; Rajta, I.; Kokavecz, J.

2011-01-01

that at low fluences the surface topography does not follow the phase change that corresponds to the irradiation pattern. At higher fluences the surface topography follows the irradiation pattern, i.e. the phase change, quite well but not perfectly. The irradiated regions are compacted significantly but their bottom is not flat. Between the irradiated regions, the unirradiated areas show a regular curved surface. This can be explained with the developed stress caused by compaction due to irradiation. During irradiation the irradiated areas start to shrink while the unirradiated areas try to remain unchanged. The topographical transition between the two phases is not a step function, but it is continuous due to the rubbery nature of PDMS. The PBW technique, that utilizes a focused MeV ion beam, is capable of the production of devices in PDMS, which have curved-edge relatively shallow, a couple of microns deep, structures on the surface. The curvature of the surface and the degree of compaction can be adjusted with the applied ion fluence and with the distance of the structures. By choosing the proper irradiation parameters short or even long range symmetrical surface curvatures can be achieved.

Cell surface area and membrane folding in glioblastoma cell lines differing in PTEN and p53 status.

Directory of Open Access Journals (Sweden)

Simon Memmel

Full Text Available Glioblastoma multiforme (GBM is characterized by rapid growth, invasion and resistance to chemo-/radiotherapy. The complex cell surface morphology with abundant membrane folds, microvilli, filopodia and other membrane extensions is believed to contribute to the highly invasive behavior and therapy resistance of GBM cells. The present study addresses the mechanisms leading to the excessive cell membrane area in five GBM lines differing in mutational status for PTEN and p53. In addition to scanning electron microscopy (SEM, the membrane area and folding were quantified by dielectric measurements of membrane capacitance using the single-cell electrorotation (ROT technique. The osmotic stability and volume regulation of GBM cells were analyzed by video microscopy. The expression of PTEN, p53, mTOR and several other marker proteins involved in cell growth and membrane synthesis were examined by Western blotting. The combined SEM, ROT and osmotic data provided independent lines of evidence for a large variability in membrane area and folding among tested GBM lines. Thus, DK-MG cells (wild type p53 and wild type PTEN exhibited the lowest degree of membrane folding, probed by the area-specific capacitance C m = 1.9 µF/cm(2. In contrast, cell lines carrying mutations in both p53 and PTEN (U373-MG and SNB19 showed the highest C m values of 3.7-4.0 µF/cm(2, which corroborate well with their heavily villated cell surface revealed by SEM. Since PTEN and p53 are well-known inhibitors of mTOR, the increased membrane area/folding in mutant GBM lines may be related to the enhanced protein and lipid synthesis due to a deregulation of the mTOR-dependent downstream signaling pathway. Given that membrane folds and extensions are implicated in tumor cell motility and metastasis, the dielectric approach presented here provides a rapid and simple tool for screening the biophysical cell properties in studies on targeting chemo- or radiotherapeutically the

Turbostratic boron nitride coated on high-surface area metal oxide templates

DEFF Research Database (Denmark)

Klitgaard, Søren Kegnæs; Egeblad, Kresten; Brorson, M.

2007-01-01

Boron nitride coatings on high-surface area MgAl2O4 and Al2O3 have been synthesized and characterized by transmission electron microscopy and by X-ray powder diffraction. The metal oxide templates were coated with boron nitride using a simple nitridation in a flow of ammonia starting from ammonium...

Surface deformation analysis over Vrancea seismogenic area through radar and GPS geospatial data

Science.gov (United States)

Zoran, Maria A.; Savastru, Roxana S.; Savastru, Dan M.; Serban, Florin S.; Teleaga, Delia M.; Mateciuc, Doru N.

2017-10-01

Time series analysis of GPS (Global Positioning Systems) and InSAR (Interferometric Synthetic Aperture Radar) data are important tools for Earth's surface deformation assessment, which can result from a wide range of geological phenomena like as earthquakes, landslides or ground water level changes. The aim of this paper was to identify several types of earthquake precursors that might be observed from geospatial data in Vrancea seismogenic region in Romania. Continuous GPS Romanian network stations and few field campaigns data recorded between 2005-2012 years revealed a displacement of about 5 or 6 millimeters per year in horizontal direction relative motion, and a few millimeters per year in vertical direction. In order to assess possible deformations due to earthquakes and respectively for possible slow deformations, have been used also time series Sentinel 1 satellite data available for Vrancea zone during October 2014 till October 2016 to generate two types of interferograms (short-term and medium- term). During investigated period were not recorded medium or strong earthquakes, so interferograms over test area revealed small displacements on vertical direction (subsidence or uplifts) of 5-10 millimeters per year. Based on GPS continuous network data and satellite Sentinel 1 results, different possible tectonic scenarios were developed. The localization of horizontal and vertical motions, fault slip, and surface deformation of the continental blocks provides new information, in support of different geodynamic models for Vrancea tectonic active region in Romania and Europe.

Surface activity of lipid extract surfactant in relation to film area compression and collapse.

Science.gov (United States)

Schürch, S; Schürch, D; Curstedt, T; Robertson, B

1994-08-01

The physical properties of modified porcine surfactant (Curosurf), isolated from minced lungs by extraction with chloroform-methanol and further purified by liquid-gel chromatography, were investigated with the captive bubble technique. Bubble size, and thus the surface tension of an insoluble film at the bubble surface, is altered by changing the pressure within the closed bubble chamber. The film surface tension and area are determined from the shape (height and diameter) of the bubble. Adsorption of fresh Curosurf is characterized by stepwise decreases in surface tension, which can easily be observed by sudden quick movements of the bubble apex. These "adsorption clicks" imply a cooperative movement of large collective units of molecules, approximately 10(14) (corresponding to approximately 120 ng of phospholipid) or approximately 10(18) molecules/m2, into the interface during adsorption. Films formed in this manner are already highly enriched in dipalmitoyl phosphatidylcholine, as seen by the extremely low compressibility, close to that of dipalmitoyl phosphatidylcholine. Near-zero minimum tensions are obtained, even at phospholipid concentrations as low as 50 micrograms/ml. During dynamic cycling (20-50 cycles/min), low minimum surface tensions, good film stability, low compressibility, and maximum surface tensions between 30 and 40 mN/m are possible only if the films are not overcompressed near zero surface tension; i.e., the overall film area compression should not substantially exceed 30%.

Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

DEFF Research Database (Denmark)

Machguth, Horst; Thomsen, Henrik H.; Weidick, Anker

2016-01-01

Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in g...

Extent of Stream Burial and Relationships to Watershed Area, Topography, and Impervious Surface Area

Directory of Open Access Journals (Sweden)

Roy E. Weitzell

2016-11-01

Full Text Available Stream burial—the routing of streams through culverts, pipes, and concrete lined channels, or simply paving them over—is common during urbanization, and disproportionately affects small, headwater streams. Burial undermines the physical and chemical processes governing life in streams, with consequences for water quality and quantity that may amplify from headwaters to downstream receiving waters. Knowledge of the extent of stream burial is critical for understanding cumulative impacts to stream networks, and for future decision-making allowing for urban development while protecting ecosystem function. We predicted stream burial across the urbanizing Potomac River Basin (USA for each 10-m stream segment in the basin from medium-resolution impervious cover data and training observations obtained from high-resolution aerial photography in a GIS. Results were analyzed across a range in spatial aggregation, including counties and independent cities, small watersheds, and regular spatial grids. Stream burial was generally correlated with total impervious surface area (ISA, with areas exhibiting ISA above 30% often subject to elevated ratios of stream burial. Recurring patterns in burial predictions related to catchment area and topographic slope were also detected. We discuss these results in the context of physiographic constraints on stream location and urban development, including implications for environmental management of aquatic resources.

Interfacial Interaction in Anodic Aluminum Oxide Templates Modifies Morphology, Surface Area, and Crystallization of Polyamide-6 Nanofibers.

Science.gov (United States)

Xue, Junhui; Xu, Yizhuang; Jin, Zhaoxia

2016-03-08

Here, we demonstrated that, when the precipitation process of polyamide-6 (PA6) solution happens in cylindrical channels of an anodized aluminum oxide membrane (AAO), interface interactions between a solid surface, solvent, non-solvent, and PA6 will influence the obtained polymer nanostructures, resulting in complex morphologies, increased surface area, and crystallization changes. With the enhancing interaction of PA6 and the AAO surface, the morphology of PA6 nanostructures changes from solid nanofibers, mesoporous, to bamboo-like, while at the same time, metastable γ-phase domains increase in these PA6 nanostructures. Brunauer-Emmett-Teller (BET) surface areas of solid, bamboo-like, and mesoporous PA6 nanofibers rise from 16, 20.9, to 25 m(2)/g. This study shows that interfacial interaction in AAO template fabrication can be used in manipulating the morphology and crystallization of one-dimensional polymer nanostructures. It also provides us a simple and novel method to create porous PA6 nanofibers with a large surface area.

Synthesis of partially graphitic ordered mesoporous carbons with high surface areas

Energy Technology Data Exchange (ETDEWEB)

Gao, Wenjun; Wan, Ying [Department of Chemistry, Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Normal University, Shanghai 200234 (China); Dou, Yuqian; Zhao, Dongyuan [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (China)

2011-01-01

Graphitic carbons with ordered mesostructure and high surface areas (of great interest in applications such as energy storage) have been synthesized by a direct triblock-copolymer-templating method. Pluronic F127 is used as a structure-directing agent, with a low-molecular-weight phenolic resol as a carbon source, ferric oxide as a catalyst, and silica as an additive. Inorganic oxides can be completely eliminated from the carbon. Small-angle XRD and N{sub 2} sorption analysis show that the resultant carbon materials possess an ordered 2D hexagonal mesostructure, uniform bimodal mesopores (about 1.5 and 6 nm), high surface area ({proportional_to}1300 m{sup 2}/g), and large pore volumes ({proportional_to}1.50 cm{sup 3}/g) after low-temperature pyrolysis (900 C). All surface areas come from mesopores. Wide-angle XRD patterns demonstrate that the presence of the ferric oxide catalyst and the silica additive lead to a marked enhancement of graphitic ordering in the framework. Raman spectra provide evidence of the increased content of graphitic sp{sup 2} carbon structures. Transmission electron microscopy images confirm that numerous domains in the ordered mesostructures are composed of characteristic graphitic carbon nanostructures. The evolution of the graphitic structure is dependent on the temperature and the concentrations of the silica additive, and ferric oxide catalyst. Electrochemical measurements performed on this graphitic mesoporous carbon when used as an electrode material for an electrochemical double layer capacitor shows rectangular-shaped cyclic voltammetry curves over a wide range of scan rates, even up to 200 mV/s, with a large capacitance of 155 F/g in KOH electrolyte. This method can be widely applied to the synthesis of graphitized carbon nanostructures. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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

Science.gov (United States)

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.

A Future Estimation of the Surface Runoff in the Greek Region: A Case Study of one of the Main Catchments Areas (Aravissos - Central Macedonia)

Science.gov (United States)

Anagnostopoulou, C.; Tolika, K.; Vafiadis, M.

2010-09-01

According to the IPCC latest report (IPCC, 2007) many semi-arid and arid areas, as the Mediterranean basin, are particularly exposed to the impacts of climate change and may suffer a decrease of water resources in the future. By the middle of the 21st century it is estimated that the annual average river runoff and water availability will decrease over these dry regions at mid-latitudes. So, it is of great importance the study of the future changes in the hydrological cycle, due to the increasing freshwater demands. The main scope of the present study is to estimate the future changes of the surface runoff in the Aravissos area (central Macedonia - Greece) due to the enhanced greenhouse effect until the end of the 21st century. The selection of Aravissos was based to the fact that the water needs of the second largest in population city in Greece (Thessaloniki) are covered mainly by the selected catchments area. Daily precipitation, temperature, relative humidity, wind speed and sunlight duration data derived from updated regional climate models, are used for selected grid points covering the domain of study. The main two climatological parameters (precipitation -temperature) are on a first step evaluated in comparison to re-analysis data (E-Obs -Ensembles project) for the same grid points. On a second step, utilizing several different evapotranspiration methods we calculated the surface runoff for two different time periods: the first in the middle and the second at the end of the 21st century. The first results of the study showed that the surface runoff depends on the methodology used for the calculation of the evapotranspiration but also from the regional model. Acknowledgements: This study has been supported by the CC-WaterS project (Contract number SEE/A/022/2.1/X)

Preparation of high surface area and high conductivity polyaniline nanoparticles using chemical oxidation polymerization technique

Science.gov (United States)

Budi, S.; Yusmaniar; Juliana, A.; Cahyana, U.; Purwanto, A.; Imaduddin, A.; Handoko, E.

2018-03-01

In this work, polyaniline nanoparticles were synthesized using a chemical oxidation polymerization technique. The ammonium peroxydisulfate (APS)/aniline ratio, APS dropping time, and polymerization temperature were optimized to increase the surface area and conductivity of the polyaniline.The Fourier-transform infrared (FTIR) spectrum confirmed the formation of emeraldine salt polyaniline. X-ray diffraction (XRD) patterns indicated that amorphous and crystalline phases of the polyaniline were formed with crystallinity less than 40%. Scanning electron microscope (SEM) micrographs showed that the finest nanoparticles with uniform size distribution were obtained at the polymerization temperature of 0°C. A surface area analyzer (SAA) showed that the highest Brunauer-Emmett-Teller surface area (SBET ) of 42.14 m2/gwas obtained from an APS/aniline ratio of 0.75 with a dropping time of 0 s at a polymerization temperature of 0°C. A four-point probe measurement conducted at 75–300K indicated relatively high conductivity of the semiconductor characteristic of the polyaniline.

Contribution to the study of techniques of measurement of interface surface area in bubble flows

International Nuclear Information System (INIS)

Veteau, Jean-Michel

1981-01-01

This research thesis addresses problems raised by the measurement of the interface area per volume unit in duct bubble flows. The author first reports a literature survey of existing methods (photographic, chemical and optical methods) which give access to the value of the parameter which is commonly named 'specific surface area'. He analyses under which conditions these methods lead to a rigorous determination of the SVIM (mean integral volume surface). The author highlights the theoretical contributions of models related to each of these methods which are indeed global methods as they allow the interface surface area to be directly obtained in a given volume of a two-phase mixture. Then, the author reports the development of an original technique based on the use of phase detecting local probes. In the next part, the author compares photographic and optical methods, on the one hand, and optical and local methods, on the other hand. Recommendations are made for the development of local methods [fr

Integrated surface-subsurface water flow modelling of the Laxemar area. Application of the hydrological model ECOFLOW

International Nuclear Information System (INIS)

Sokrut, Nikolay; Werner, Kent; Holmen, Johan

2007-01-01

Since 2002, the Swedish Nuclear Fuel and Waste Management Co (SKB) performs site investigations in the Simpevarp area, for the siting of a deep geological repository for spent nuclear fuel. The site descriptive modelling includes conceptual and quantitative modelling of surface-subsurface water interactions, which are key inputs to safety assessment and environmental impact assessment. Such modelling is important also for planning of continued site investigations. In this report, the distributed hydrological model ECOFLOW is applied to the Laxemar subarea to test the ability of the model to simulate surface water and near-surface groundwater flow, and to illustrate ECOFLOW's advantages and drawbacks. The ECOFLOW model area is generally characterised by large areas of exposed or shallow bedrock. The ECOFLOW modelling results are compared to previous results produced by MIKE SHE-MIKE 11 and PCRaster-POLFLOW, in order to check whether non-calibrated surface and subsurface water flows computed by ECOFLOW are consistent with these previous results. The analyses include quantification and comparison of inflow and outflow terms of the water balance, as well as analyses of groundwater recharge-discharge patterns. ECOFLOW is used to simulate a one-year non calibrated period, considering seven catchments (including three areas with direct runoff to the sea) within the Laxemar subarea. The modelling results show the ability of the model to produce reasonable results for a model domain including both porous media (Quaternary deposits) and discontinuous media (bedrock). The results demonstrate notable differences in the specific discharge between the considered catchments, with specific discharge values in the range 157-212 mm/year; the lowest value (the Lake Frisksjoen catchment) may however be erroneous due to numerical instability in the model. Overall, these results agree with specific discharge values computed by MIKE SHE-MIKE 11 and PCRaster-POLFLOW (190 and 128-186 mm

Integrated surface-subsurface water flow modelling of the Laxemar area. Application of the hydrological model ECOFLOW

Energy Technology Data Exchange (ETDEWEB)

Sokrut, Nikolay; Werner, Kent; Holmen, Johan [Golder Associates AB, Uppsala (Sweden)

2007-01-15

Since 2002, the Swedish Nuclear Fuel and Waste Management Co (SKB) performs site investigations in the Simpevarp area, for the siting of a deep geological repository for spent nuclear fuel. The site descriptive modelling includes conceptual and quantitative modelling of surface-subsurface water interactions, which are key inputs to safety assessment and environmental impact assessment. Such modelling is important also for planning of continued site investigations. In this report, the distributed hydrological model ECOFLOW is applied to the Laxemar subarea to test the ability of the model to simulate surface water and near-surface groundwater flow, and to illustrate ECOFLOW's advantages and drawbacks. The ECOFLOW model area is generally characterised by large areas of exposed or shallow bedrock. The ECOFLOW modelling results are compared to previous results produced by MIKE SHE-MIKE 11 and PCRaster-POLFLOW, in order to check whether non-calibrated surface and subsurface water flows computed by ECOFLOW are consistent with these previous results. The analyses include quantification and comparison of inflow and outflow terms of the water balance, as well as analyses of groundwater recharge-discharge patterns. ECOFLOW is used to simulate a one-year non calibrated period, considering seven catchments (including three areas with direct runoff to the sea) within the Laxemar subarea. The modelling results show the ability of the model to produce reasonable results for a model domain including both porous media (Quaternary deposits) and discontinuous media (bedrock). The results demonstrate notable differences in the specific discharge between the considered catchments, with specific discharge values in the range 157-212 mm/year; the lowest value (the Lake Frisksjoen catchment) may however be erroneous due to numerical instability in the model. Overall, these results agree with specific discharge values computed by MIKE SHE-MIKE 11 and PCRaster-POLFLOW (190 and 128

High sensitivity, high surface area Enzyme-linked Immunosorbent Assay (ELISA).

Science.gov (United States)

Singh, Harpal; Morita, Takahiro; Suzuki, Yuma; Shimojima, Masayuki; Le Van, An; Sugamata, Masami; Yang, Ming

2015-01-01

Enzyme-linked immunosorbent assays (ELISA) are considered the gold standard in the demonstration of various immunological reactions with an application in the detection of infectious diseases such as during outbreaks or in patient care. This study aimed to produce an ELISA-based diagnostic with an increased sensitivity of detection compared to the standard 96-well method in the immunologic diagnosis of infectious diseases. A '3DStack' was developed using readily available, low cost fabrication technologies namely nanoimprinting and press stamping with an increased surface area of 4 to 6 times more compared to 96-well plates. This was achieved by stacking multiple nanoimprinted polymer sheets. The flow of analytes between the sheets was enhanced by rotating the 3DStack and confirmed by Finite-Element (FE) simulation. An Immunoglobulin G (IgG) ELISA for the detection of antibodies in human serum raised against Rubella virus was performed for validation. An improved sensitivity of up to 1.9 folds higher was observed using the 3DStack compared to the standard method. The increased surface area of the 3DStack developed using nanoimprinting and press stamping technologies, and the flow pattern between sheets generated by rotating the 3DStack were potential contributors to a more sensitive ELISA-based diagnostic device.

Changes in thickness and surface area of the human cortex and their relationship with intelligence.

Science.gov (United States)

Schnack, Hugo G; van Haren, Neeltje E M; Brouwer, Rachel M; Evans, Alan; Durston, Sarah; Boomsma, Dorret I; Kahn, René S; Hulshoff Pol, Hilleke E

2015-06-01

Changes in cortical thickness over time have been related to intelligence, but whether changes in cortical surface area are related to general cognitive functioning is unknown. We therefore examined the relationship between intelligence quotient (IQ) and changes in cortical thickness and surface over time in 504 healthy subjects. At 10 years of age, more intelligent children have a slightly thinner cortex than children with a lower IQ. This relationship becomes more pronounced with increasing age: with higher IQ, a faster thinning of the cortex is found over time. In the more intelligent young adults, this relationship reverses so that by the age of 42 a thicker cortex is associated with higher intelligence. In contrast, cortical surface is larger in more intelligent children at the age of 10. The cortical surface is still expanding, reaching its maximum area during adolescence. With higher IQ, cortical expansion is completed at a younger age; and once completed, surface area decreases at a higher rate. These findings suggest that intelligence may be more related to the magnitude and timing of changes in brain structure during development than to brain structure per se, and that the cortex is never completed but shows continuing intelligence-dependent development. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Modification of Surface Roughness and Area of FeCrAl Substrate for Catalytic Converter using Ultrasonic Treatment

Directory of Open Access Journals (Sweden)

Yanuandri Putrasari

2012-03-01

Full Text Available Surface roughness and area play important role especially in deposition and reaction of the catalyst in the catalytic converter substrate. The aim of this paper is to show the modification of surface roughness and area of FeCrAl substrate for catalytic converter using ultrasonic method. The method was conducted by agitating the FeCrAl in 10 minutes 35 kHz ultrasonic cleaning bath. The  surface roughness, morphology, and chemical components of FeCrAl catalytic converter substrate after ultrasonic treatment were analyzed using atomic force microscope (AFM and examined with scanning electron microscope (SEM in combination with energy dispersive X-ray spectroscopy (EDS. The ultrasonic treatment assisted with Al2O3 powders successfully increased the roughness and surface area of FeCrAl better than SiC powders. 

30 CFR 717.15 - Disposal of excess rock and earth materials on surface areas.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess rock and earth materials on surface areas. 717.15 Section 717.15 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS UNDERGROUND MINING GENERAL PERFORMANCE STANDARDS § 717.15 Disposal of excess rock and...

Aerosol removal due to precipitation and wind forcings in Milan urban area

Science.gov (United States)

Cugerone, Katia; De Michele, Carlo; Ghezzi, Antonio; Gianelle, Vorne

2018-01-01

Air pollution represents a critical issue in Milan urban area (Northern Italy). Here, the levels of fine particles increase, overcoming the legal limits, mostly in wintertime, due to favourable calm weather conditions and large heating and vehicular traffic emissions. The main goal of this work is to quantify the aerosol removal effect due to precipitation at the ground. At first, the scavenging coefficients have been calculated for aerosol particles with diameter between 0.25 and 3 μm. The average values of this coefficient vary between 2 ×10-5 and 5 ×10-5 s-1. Then, the aerosol removal induced separately by precipitation and wind have been compared through the introduction of a removal index. As a matter of fact, while precipitation leads to a proper wet scavenging of the particles from the atmosphere, high wind speeds cause enhanced particle dispersion and dilution, that locally bring to a tangible decrease of aerosol particles' number. The removal triggered by these two forcings showed comparable average values, but different trends. The removal efficiency of precipitation lightly increases with the increase of particle diameters and vice versa happens with strong winds.

Hydrothermal Synthesis of Highly Water-dispersible Anatase Nanoparticles with Large Specific Surface Area and Their Adsorptive Properties

Directory of Open Access Journals (Sweden)

Hu Xueting

2016-01-01

Full Text Available Highly water-dispersible and very small TiO2 nanoparticles (~3 nm anatase with large specific surface area have been synthesized by hydrolysis and hydrothermal reactions of titanium butoxide and used for the removal of three azo dyes (Congo red, orange II, and methyl orange with different molecular structure from simulated wastewaters. The synthesized TiO2 nanoparticles are well dispersed in water with large specific surface area up to 417 m2 g−1. Adsorption experiments demonstrated that the water-dispersible TiO2 nanoparticles possess excellent adsorption capacities for Congo red, orange II, and methyl orange, which could be attributed to their good water-dispersibility and large specific surface area.

Changes in Thickness and Surface Area of the Human Cortex and Their Relationship with Intelligence

NARCIS (Netherlands)

Schnack, H.G.; van Haren, N.E.M.; Brouwer, R.M.; Evans, A.; Durston, S.; Boomsma, D.I.; Kahn, R.S.; Hulshoff Pol, H.E.

2015-01-01

Changes in cortical thickness over time have been related to intelligence, but whether changes in cortical surface area are related to general cognitive functioning is unknown. We therefore examined the relationship between intelligence quotient (IQ) and changes in cortical thickness and surface

Measuring stone surface area from a radiographic image is accurate and reproducible with the help of an imaging program.

Science.gov (United States)

Kurien, Abraham; Ganpule, Arvind; Muthu, V; Sabnis, R B; Desai, Mahesh

2009-01-01

The surface area of the stone from a radiographic image is one of the more suitable parameters defining stone bulk. The widely accepted method of measuring stone surface area is to count the number of square millimeters enclosed within a tracing of the stone outline on graph paper. This method is time consuming and cumbersome with potential for human error, especially when multiple measurements are needed. The purpose of this study was to evaluate the accuracy, efficiency, and reproducibility of a commercially available imaging program, Adobe Photoshop 7.0 for the measurement of stone surface area. The instructions to calculate area using the software are simple and easy in a Windows-based format. The accuracy of the imaging software was estimated by measuring surface areas of shapes of known mathematical areas. The efficiency and reproducibility were then evaluated from radiographs of 20 persons with radiopaque upper-tract urinary stones. The surface areas of stone images were measured using both graph paper and imaging software. Measurements were repeated after 10 days to assess the reproducibility of the techniques. The time taken to measure the area by the two methods was also assessed separately. The accuracy of the imaging software was estimated to be 98.7%. The correlation coefficient between the two methods was R(2) = 0.97. The mean percentage variation using the imaging software was 0.68%, while it was 6.36% with the graph paper. The mean time taken to measure using the image analyzer and graph paper was 1.9 +/- 0.8 minutes and 4.5 +/- 1.08 minutes, respectively (P stone surface area from radiographs compared with manual measurements using graph paper.

Aggregate surface areas quantified through laser measurements for South African asphalt mixtures

CSIR Research Space (South Africa)

Anochie-Boateng, Joseph

2012-02-01

Full Text Available design. This paper introduces the use of a three-dimensional (3D) laser scanning method to directly measure the surface area of aggregates used in road pavements in South Africa. As an application of the laser-based measurements, the asphalt film...

Evaluation of an atmospheric model with surface and ABL meteorological data for energy applications in structured areas

Science.gov (United States)

Triantafyllou, A. G.; Kalogiros, J.; Krestou, A.; Leivaditou, E.; Zoumakis, N.; Bouris, D.; Garas, S.; Konstantinidis, E.; Wang, Q.

2018-03-01

This paper provides the performance evaluation of the meteorological component of The Air Pollution Model (TAPM), a nestable prognostic model, in predicting meteorological variables in urban areas, for both its surface layer and atmospheric boundary layer (ABL) turbulence parameterizations. The model was modified by incorporating four urban land surface types, replacing the existing single urban surface. Control runs were carried out over the wider area of Kozani, an urban area in NW Greece. The model was evaluated for both surface and ABL meteorological variables by using measurements of near-surface and vertical profiles of wind and temperature. The data were collected by using monitoring surface stations in selected sites as well as an acoustic sounder (SOnic Detection And Ranging (SODAR), up to 300 m above ground) and a radiometer profiler (up to 600 m above ground). The results showed the model demonstrated good performance in predicting the near-surface meteorology in the Kozani region for both a winter and a summer month. In the ABL, the comparison showed that the model's forecasts generally performed well with respect to the thermal structure (temperature profiles and ABL height) but overestimated wind speed at the heights of comparison (mostly below 200 m) up to 3-4 ms-1.

Description of climate, surface hydrology, and near-surface hydrogeology. Preliminary site description. Forsmark area - version 1.2

Energy Technology Data Exchange (ETDEWEB)

Johansson, Per-Olof [Artesia Grundvattenkonsult AB, Stockholm (Sweden); Werner, Kent [SWECO VIAK AB/Golder Associates AB, Stockholm (Sweden); Bosson, Emma; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Juston, John [DBE Sweden, Uppsala (Sweden)

2005-06-15

The Swedish Nuclear Fuel and Waste Management Company (SKB) is conducting site investigations at two different locations, the Forsmark and Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. The results from the investigations at the sites are used as a basic input to the development of Site Descriptive Models (SDM). The SDM shall summarise the current state of knowledge of the site, and provide parameters and models to be used in further analyses within Safety Assessment, Repository Design and Environmental Impact Assessment. The present report is a background report describing the meteorological conditions and the modelling of surface hydrology and near-surface hydrogeology in support of the Forsmark version 1.2 SDM based on the data available in the Forsmark 1.2 'data freeze' (July 31, 2004). The groundwater is very shallow, with groundwater levels within one meter below ground as an annual mean for almost all groundwater monitoring wells. Also, the annual groundwater level amplitude is less than 1.5 m for most wells. The shallow groundwater levels mean that there is a strong interaction between evapotranspiration, soil moisture and groundwater. In the modelling, surface water and near-surface groundwater divides are assumed to coincide. The small-scale topography implies that many local, shallow groundwater flow systems are formed in the Quaternary deposits, overlaying more large-scale flow systems associated with groundwater flows at greater depths. Groundwater level time series from wells in till and bedrock within the same areas show a considerably higher groundwater level in the till than in the bedrock. The observed differences in levels are not fully consistent with the good hydraulic contact between overburden and bedrock indicated by the hydraulic tests in the Quaternary deposits. However, the relatively lower groundwater levels in the bedrock may be caused by the horizontal to sub-horizontal highly

Doses to early entrants to the A-bombed areas and to residents of the fallout areas and 137Cs in soil of the 'black rain' area in Hiroshima

International Nuclear Information System (INIS)

Takeshita, Kenji

1976-01-01

An external exposure dose from residual activity (induced radioactivity in the fallout areas and radioactive fallout in the ''black rain'' area) caused by an atomic bomb in Hiroshima was estimated. The integrated doses to the infinite time averaged 101 rads in the atomic bombed area of Hiroshima and 32 rads in that area of Nagasaki. According to the measurement by investigators, the integrated doses of the external exposure dose due to radioactive fallout averaged 13 rads. The amount of 137 Cs in soils was determined in the southest slanting surface

Distributions of dissolved monosaccharides and polysaccharides in the surface microlayer and surface water of the Jiaozhou Bay and its adjacent area

Science.gov (United States)

Zhang, Yan-Ping; Yang, Gui-Peng; Lu, Xiao-Lan; Ding, Hai-Bing; Zhang, Hong-Hai

2013-07-01

Sea surface microlayer (SML) samples and corresponding bulk surface water (SW) samples were collected in the Jiaozhou Bay and its adjacent area in July and November 2008. The average concentrations of dissolved monosaccharides (MCHO) and polysaccharides (PCHO) revealed similar temporal variability, with higher concentrations during the green-tide period (in July) than during the non-green-tide period (in November). Average enrichment factors (EF) of MCHO and PCHO, defined as the ratio of the concentration in the SML to that in the SW, were 1.3 and 1.4 in July, respectively, while those values in November were 1.9 and 1.6. Our data also showed that the concentrations of MCHO and PCHO in the SML were strongly correlated with those in the SW, indicating that most of the organic materials in the SML came from the SW. The total dissolved carbohydrate concentrations (TDCHO) in the bulk surface water were closely correlated with salinity during the cruises (July: r=-0.580, n=18, P=0.01; November: r=-0.679, n=26, P<0.001), suggesting that riverine input had an important effect on the distribution of TDCHO in surface seawater of the study area.

A process to enhance the specific surface area and capacitance of hydrothermally reduced graphene oxide

KAUST Repository

Alazmi, Amira

2016-08-26

The impact of post-synthesis processing in reduced graphene oxide materials for supercapacitor electrodes has been analyzed. A comparative study of vacuum, freeze and critical point drying was carried out for hydrothermally reduced graphene oxide demonstrating that the optimization of the specific surface area and preservation of the porous network are critical to maximize its supercapacitance performance. As described below, using a supercritical fluid as the drying medium, unprecedented values of the specific surface area (364 m2 g−1) and supercapacitance (441 F g−1) for this class of materials have been achieved.

A process to enhance the specific surface area and capacitance of hydrothermally reduced graphene oxide

KAUST Repository

Alazmi, Amira; El Tall, Omar; Rasul, Shahid; Hedhili, Mohamed N.; Patole, Shashikant P.; Da Costa, Pedro M. F. J.

2016-01-01

The impact of post-synthesis processing in reduced graphene oxide materials for supercapacitor electrodes has been analyzed. A comparative study of vacuum, freeze and critical point drying was carried out for hydrothermally reduced graphene oxide demonstrating that the optimization of the specific surface area and preservation of the porous network are critical to maximize its supercapacitance performance. As described below, using a supercritical fluid as the drying medium, unprecedented values of the specific surface area (364 m2 g−1) and supercapacitance (441 F g−1) for this class of materials have been achieved.

Segmental equivalent temperature determined by means of a thermal manikin: A method for correcting errors due to incomplete contact of the body with a surface

DEFF Research Database (Denmark)

Melikov, Arsen Krikor; Janieas, N.R.D.J.; Silva, M.C.G.

2004-01-01

of the thermal manikins used at present is not as flexible as the human body and is divided into body segments with a surface area that differs from that of the human body in contact with a surface. The area of the segment in contact with a surface will depend on the shape and flexibility of the surface...

Estimation of the reactive mineral surface area during CO2-rich fluid-rock interaction: the influence of neogenic phases

Science.gov (United States)

Scislewski, A.; Zuddas, P.

2010-12-01

Mineral dissolution and precipitation reactions actively participate to control fluid chemistry during water-rock interaction. It is however, difficult to estimate and well normalize bulk reaction rates if the mineral surface area exposed to the aqueous solution and effectively participating on the reactions is unknown. We evaluated the changing of the reactive mineral surface area during the interaction between CO2-rich fluids and Albitite/Granitoid rocks (similar mineralogy but different abundances), reacting under flow-through conditions. Our methodology, adopting an inverse modeling approach, is based on the estimation of dissolution rate and reactive surface area of the different minerals participating in the reactions by the reconstruction the chemical evolution of the interacting fluids. The irreversible mass-transfer processes is defined by a fractional degree of advancement, while calculations were carried out for Albite, Microcline, Biotite and Calcite assuming that the ion activity of dissolved silica and aluminium ions was limited by the equilibrium with quartz and kaolinite. Irrespective of the mineral abundance in granite and albitite, we found that mineral dissolution rates did not change significantly in the investigated range of time where output solution’s pH remained in the range between 6 and 8, indicating that the observed variation in fluid composition depends not on pH but rather on the variation of the parent mineral’s reactive surface area. We found that the reactive surface area of Albite varied by more than 2 orders of magnitude, while Microcline, Calcite and Biotite surface areas changed by 1-2 orders of magnitude. We propose that parent mineral chemical heterogeneity and, particularly, the stability of secondary mineral phases may explain the observed variation of the reactive surface area of the minerals. Formation of coatings at the dissolving parent mineral surfaces significantly reduced the amount of surface available to react

Earth modeling and estimation of the local seismic ground motion due to site geology in complex volcanoclastic areas

Directory of Open Access Journals (Sweden)

V. Di Fiore

2002-06-01

Full Text Available Volcanic areas often show complex behaviour as far as seismic waves propagation and seismic motion at surface are concerned. In fact, the finite lateral extent of surface layers such as lava flows, blocks, differential welding and/or zeolitization within pyroclastic deposits, introduces in the propagation of seismic waves effects such as the generation of surface waves at the edge, resonance in lateral direction, diffractions and scattering of energy, which tend to modify the amplitude as well as the duration of the ground motion. The irregular topographic surface, typical of volcanic areas, also strongly influences the seismic site response. Despite this heterogeneity, it is unfortunately a common geophysical and engineering practice to evaluate even in volcanic environments the subsurface velocity field with monodimensional investigation method (i.e. geognostic soundings, refraction survey, down-hole, etc. prior to the seismic site response computation which in a such cases is obviously also made with 1D algorithms. This approach often leads to highly inaccurate results. In this paper we use a different approach, i.e. a fully 2D P-wave Çturning rayÈ tomographic survey followed by 2D seismic site response modeling. We report here the results of this approach in three sites located at short distance from Mt. Vesuvius and Campi Flegrei and characterized by overburdens constituted by volcanoclastic deposits with large lateral and vertical variations of their elastic properties. Comparison between 1D and 2D Dynamic Amplification Factor shows in all reported cases entirely different results, both in terms of peak period and spectral contents, as expected from the clear bidimensionality of the geological section. Therefore, these studies suggest evaluating carefully the subsoil geological structures in areas characterized by possible large lateral and vertical variations of the elastic properties in order to reach correct seismic site response

Surface and ground waters evaluation at Brazilian Multiproposed Reactor installation area

International Nuclear Information System (INIS)

Stellato, Thamiris B.; Silva, Tatiane B.S.C.da; Soares, Sabrina M.V.; Faustino, Mainara G.; Marques, Joyce R.; Oliveira, Cintia C. de; Monteiro, Lucilena R.; Pires, Maria A.F.; Cotrim, Marycel E.B.

2017-01-01

This study evaluates six surface and ground waters physicochemical characteristics on the area of the future Brazilian Multipurpose Reactor (RMB), at Iperó/SP. One of the main goals is to establish reference values for future operation monitoring programs, as well as for environmental permits and regulation. Considering analyzed parameters, all collection points presented values within CONAMA Resolution 396/08 and 357/05 regulation limits, showing similar characteristics among collection points.Only two points groundwater (RMB-005 and RMB-006) presented higher alkalinity, total dissolved solids and conductivity. The studied area was considered in good environmental conservation condition, as far as water quality is concerned. (author)

Characterization of the intragranular water regime within subsurface sediments: pore volume, surface area, and mass transfer limitations

Science.gov (United States)

Hay, Michael B.; Stoliker, Deborah L.; Davis, James A.; Zachara, John M.

2011-01-01

Although "intragranular" pore space within grain aggregates, grain fractures, and mineral surface coatings may contain a relatively small fraction of the total porosity within a porous medium, it often contains a significant fraction of the reactive surface area, and can thus strongly affect the transport of sorbing solutes. In this work, we demonstrate a batch experiment procedure using tritiated water as a high-resolution diffusive tracer to characterize the intragranular pore space. The method was tested using uranium-contaminated sediments from the vadose and capillary fringe zones beneath the former 300A process ponds at the Hanford site (Washington). Sediments were contacted with tracers in artificial groundwater, followed by a replacement of bulk solution with tracer-free groundwater and the monitoring of tracer release. From these data, intragranular pore volumes were calculated and mass transfer rates were quantified using a multirate first-order mass transfer model. Tritium-hydrogen exchange on surface hydroxyls was accounted for by conducting additional tracer experiments on sediment that was vacuum dried after reaction. The complementary ("wet" and "dry") techniques allowed for the simultaneous determination of intragranular porosity and surface area using tritium. The Hanford 300A samples exhibited intragranular pore volumes of ~1% of the solid volume and intragranular surface areas of ~20%–35% of the total surface area. Analogous experiments using bromide ion as a tracer yielded very different results, suggesting very little penetration of bromide into the intragranular porosity.

Mining-induced surface damage and the study of countermeasures

International Nuclear Information System (INIS)

Cui Jixian

1994-01-01

Coal constitutes China's major energy resource. The majority of the coal is produced from underground mining operations. Surface subsidence may amount to 80% of the thickness of the seam mined, while the subsided volume is around 60% of the mined volume underground. An area of 20 hectares of land will be affected with each 1 million tons of coal mined, thereby causing severe surface damage. Following a description of the characteristics of surface damages due to underground mining disturbance, this paper elaborates on the damage prediction method, standards applied for evaluating the damages experienced by surface buildings, land reclamation methods in subsided area, measures for reinforcing and protecting buildings in mining-affected areas, and performance of antideformation buildings

Thermal infrared imagery as a tool for analysing the variability of surface saturated areas at various temporal and spatial scales

Science.gov (United States)

Glaser, Barbara; Antonelli, Marta; Pfister, Laurent; Klaus, Julian

2017-04-01

Surface saturated areas are important for the on- and offset of hydrological connectivity within the hillslope-riparian-stream continuum. This is reflected in concepts such as variable contributing areas or critical source areas. However, we still lack a standardized method for areal mapping of surface saturation and for observing its spatiotemporal variability. Proof-of-concept studies in recent years have shown the potential of thermal infrared (TIR) imagery to record surface saturation dynamics at various temporal and spatial scales. Thermal infrared imagery is thus a promising alternative to conventional approaches, such as the squishy boot method or the mapping of vegetation. In this study we use TIR images to investigate the variability of surface saturated areas at different temporal and spatial scales in the forested Weierbach catchment (0.45 km2) in western Luxembourg. We took TIR images of the riparian zone with a hand-held FLIR infrared camera at fortnightly intervals over 18 months at nine different locations distributed over the catchment. Not all of the acquired images were suitable for a derivation of the surface saturated areas, as various factors influence the usability of the TIR images (e.g. temperature contrasts, shadows, fog). Nonetheless, we obtained a large number of usable images that provided a good insight into the dynamic behaviour of surface saturated areas at different scales. The images revealed how diverse the evolution of surface saturated areas can be throughout the hydrologic year. For some locations with similar morphology or topography we identified diverging saturation dynamics, while other locations with different morphology / topography showed more similar behaviour. Moreover, we were able to assess the variability of the dynamics of expansion / contraction of saturated areas within the single locations, which can help to better understand the mechanisms behind surface saturation development.

Uncovering surface area and micropores in almond shell biochars by rainwater wash

Science.gov (United States)

Biochars have been considered for adsorption of contaminants in soil and water, as well as conditioning and improving soil quality. One important property of the biochar is surface area in the pores of the biochar. Biochars were created from almond shells from two almond varieties with different ash...

Effects of acid treatment on the clay palygorskite: XRD, surface area, morphological and chemical composition

Energy Technology Data Exchange (ETDEWEB)

Xavier, Katiane Cruz Magalhaes; Santos, Maria do Socorro Ferreira dos; Santos, Maria Rita Morais Chaves; Oliveira, Marilia Evelyn Rodrigues; Osajima, Josy Antevelli; Silva Filho, Edson Cavalcanti da [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil); Carvalho, Maria Wilma Nunes Cordeiro, E-mail: edsonfilho@ufpi.edu.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil)

2014-08-15

The palygorskite is an aluminum-magnesium silicate that has a fibrous morphology. Their physicochemical characteristics are the result of high surface area, porosity and thermal resistance which make it an attractive adsorbent. Its adsorption capacity can be increased through chemical reactions and/or heat treatments. The objective of this work is to verify the effects of acid activation on the palygorskite, treated with HCl at 90 °C at concentrations of 2, 4 and 6 mol L{sup -1} in 2 and 4 hours, with clay/acid solution ratio 1 g 10 mL{sup -1} and characterized by techniques: XRF, XRD and surface area. A significant increase in specific surface area was observed in the sample treated with HCl at the concentration 6 mol L{sup -1}. The changes were more pronounced at stricter concentrations of acidity, with decreasing intensity of reflection of the clay indicated in the XRD. These changes were confirmed in the XRF with the leaching of some oxides and with increasing concentration of SiO{sub 2}. (author)

Acid/base bifunctional carbonaceous nanomaterial with large surface area: Preparation, characterization, and adsorption properties for cationic and anionic compounds

Energy Technology Data Exchange (ETDEWEB)

Li, Kai; Ma, Chun–Fang; Ling, Yuan; Li, Meng [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Gao, Qiang, E-mail: gaoqiang@cug.edu.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Engineering Research Center of Nano-Geo Materials of Ministry of Education, China University of Geosciences, Wuhan 430074 (China); Luo, Wen–Jun, E-mail: heartnohome@yahoo.com.cn [Department of Chemistry, Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China)

2015-07-15

Nanostructured carbonaceous materials are extremely important in the nano field, yet developing simple, mild, and “green” methods that can make such materials possess large surface area and rich functional groups on their surfaces still remains a considerable challenge. Herein, a one-pot and environment-friendly method, i.e., thermal treatment (180 °C; 18 h) of water mixed with glucose and chitosan (CTS), has been proposed. The resultant carbonaceous nanomaterials were characterized by field emitting scanning electron microscope, N{sub 2} adsorption/desorption, Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, and zeta-potential analysis. It was found that, in contrast to the conventional hydrothermally carbonized product from pure glucose, with low surface area (9.3 m{sup 2} g{sup −1}) and pore volume (0.016 cm{sup 3} g{sup −1}), the CTS-added carbonaceous products showed satisfactory textural parameters (surface area and pore volume up to 254 m{sup 2} g{sup −1} and 0.701 cm{sup 3} g{sup −1}, respectively). Moreover, it was also interestingly found that these CTS-added carbonaceous products possessed both acidic (–COOH) and basic (–NH{sub 2}) groups on their surfaces. Taking the advantages of large surface area and –COOH/–NH{sub 2} bifunctional surface, the carbonaceous nanomaterials exhibited excellent performance for adsorptions of cationic compound (i.e., methylene blue) at pH 10 and anionic compound (i.e., acid red 18) at pH 2, respectively. This work not only provides a simple and green route to prepare acid/base bifunctional carbonaceous nanomaterials with large surface area but also well demonstrates their potential for application in adsorption. - Highlights: • A simple and green method was proposed to prepare carbon nanomaterials. • The carbon product showed acid/base bifunctional surface with large surface area. • The carbon material could efficiently adsorb both cationic and anionic compounds.

Potentiometric Surface of the Alluvial Aquifer and Hydrologic Conditions in the Juana Diaz area, Puerto Rico, June 29 - July 1, 2005

Science.gov (United States)

Rodriguez, Jose M.; Santigo-Rivera, Luis; Gómez-Gómez, Fernando

2006-01-01

A synoptic survey of the hydrologic conditions in the Juana Diaz area, Puerto Rico, was conducted between June 29 and July 1, 2005, to define the spatial distribution of the potentiometric surface of the alluvial aquifer. The study area encompasses 21 square miles of the more extensive South Coastal Plain Alluvial Aquifer system and is bounded along the north by foothills of the Cordillera Central mountain chain, to the south by the Caribbean Sea, the east by the Rio Descalabrado and to the west by the Rio Inabon. Ground water in the Juana Diaz area is in the Quaternary-age alluvial deposits and the middle-Tertiary age Ponce Limestone and Juana Diaz Formation (Giusti, 1968). The hydraulic properties of the Ponce Limestone in the Juana Diaz area are unknown, and the Juana Diaz Formation is a unit of poor permeability due to its high clay content. Consequently, the Ponce Limestone and the Juana Diaz Formation are generally considered to be the base of the alluvial aquifer in the Juana Diaz area with ground-water flow occurring primarily within the alluvial deposits. The potentiometric-surface map of the alluvial aquifer was delineated using ground-water level measurements taken at existing wells. The water-level measurements were taken at wells that were either not pumping during the survey or were shut down for a brief period. In the latter case, a recovery period of 30 minutes was allowed for the drawdown in the wellbore to achieve a near static level position representative of the aquifer at the measurement point. Land-surface altitude from U.S. Geological Survey (USGS) 1:20,000 scale topographic maps (Playa de Ponce, Ponce, Rio Descalabrado, and Santa Isabel) were used to refer ground-water levels to mean sea level datum (National Geodetic Vertical Datum of 1929). In addition to the ground-water level measurements, the potentiometricsurface contours were delineated using hydrologic features, such as drainage ditches and saturated intermittent streams that were

Nox diffusion-simulation in an urban area in using the vertical diffusion diagram including a surface roughness parameter

Energy Technology Data Exchange (ETDEWEB)

Kono, Hitoshi; Fujimoto, Akira; Nakano, Hiroshi

1988-03-31

In recent years, in order to attain a total quantity regulation of air pollution and to prepare a local air-control program, a diffusion simulation is often made using a Gaussian plume model. NOx diffusion simulation of the urban area was carried out using a vertical diffusion width by taking a parameter of ground-surface roughness using Smith's correction to the Gaussian model. For the diffusion of car exhaust gas, comparison was made for the estimate and the measurement by jointly using the values of ground-surface roughness and the initial diffusion width. As a result, change in the diffusion width of the car exhaust gas due to the urban buildings was expressed at a necessary practical level by giving the height of the point of calculation, 1 - 3 m in the central part and 30 cm at the peripheral part, and giving the initial diffusion width of roughly half to equal size of initial diffusion width to the average height of the buildings. (2 figs, 8 tabs, 20 refs)

Mapping paddy rice planting areas through time series analysis of MODIS land surface temperature and vegetation index data.

Science.gov (United States)

Zhang, Geli; Xiao, Xiangming; Dong, Jinwei; Kou, Weili; Jin, Cui; Qin, Yuanwei; Zhou, Yuting; Wang, Jie; Menarguez, Michael Angelo; Biradar, Chandrashekhar

2015-08-01

Knowledge of the area and spatial distribution of paddy rice is important for assessment of food security, management of water resources, and estimation of greenhouse gas (methane) emissions. Paddy rice agriculture has expanded rapidly in northeastern China in the last decade, but there are no updated maps of paddy rice fields in the region. Existing algorithms for identifying paddy rice fields are based on the unique physical features of paddy rice during the flooding and transplanting phases and use vegetation indices that are sensitive to the dynamics of the canopy and surface water content. However, the flooding phenomena in high latitude area could also be from spring snowmelt flooding. We used land surface temperature (LST) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to determine the temporal window of flooding and rice transplantation over a year to improve the existing phenology-based approach. Other land cover types (e.g., evergreen vegetation, permanent water bodies, and sparse vegetation) with potential influences on paddy rice identification were removed (masked out) due to their different temporal profiles. The accuracy assessment using high-resolution images showed that the resultant MODIS-derived paddy rice map of northeastern China in 2010 had a high accuracy (producer and user accuracies of 92% and 96%, respectively). The MODIS-based map also had a comparable accuracy to the 2010 Landsat-based National Land Cover Dataset (NLCD) of China in terms of both area and spatial pattern. This study demonstrated that our improved algorithm by using both thermal and optical MODIS data, provides a robust, simple and automated approach to identify and map paddy rice fields in temperate and cold temperate zones, the northern frontier of rice planting.

Survey of radioactive contamination distribution in the Naka-Dori area, Tohoku, Japan

International Nuclear Information System (INIS)

Hohara, Sin-ya; Inagaki, Masayo; Yamanishi, Hirokuni; Wakabayashi, Genichiro; Sugiyama, Wataru; Itoh, Tetsuo

2013-01-01

The Kinki University Atomic Energy Research Institute investigated radioactive contamination due to the Fukushima Daiichi Nuclear Power Plant accident in urban areas of the Fukushima Naka-Dori Area in the TOHOKU region, Japan. A specific activity measurement of the surface soil and a survey of the dose rate distribution in urban areas were performed. From the results of this research, a decrease in dose rate in paved areas became clear, and differences due to the “wash out effect” in paved areas for different paving materials was measured and verified. (author)

Pure phase LaFeO3 perovskite with improved surface area synthesized using different routes and its characterization

International Nuclear Information System (INIS)

Gosavi, Priti V.; Biniwale, Rajesh B.

2010-01-01

Three different wet chemistry routes, namely co-precipitation, combustion and sol-gel methods were used to synthesize LaFeO 3 perovskite with improved surface area. The synthesized perovskite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometer (EDS), Brunauer-Emmett-Teller (BET) nitrogen adsorption, ultraviolet diffused reflectance spectroscopy (UVDRS) and Fourier transform infrared (FTIR) spectroscopy techniques. Improved surface area was observed for all three methods as compared to the previously reported values. The perovskite synthesized using sol-gel method yields comparatively pure, crystalline phase of LaFeO 3 and relatively higher surface area of 16.5 m 2 g -1 and porosity. The material synthesized using co-precipitation method yielded other phases in addition to the targeted phase. The morphology of perovskite synthesized using co-precipitation method was uniform agglomerates. Combustion method yields flakes type morphology and that of sol-gel method was open pore type morphology. The selection of method for perovskite synthesis largely depends on the targeted application and the desired properties of perovskites. The results reported in this study are useful for establishing a simple scalable method for preparation of high surface area LaFeO 3 as compared to solid-oxide method. Further, the typical heating cycle followed for calcinations resulted in relatively high surface area in the case of all three methods.

Surface area of lactose and lactose granulates on consolidation and compaction

OpenAIRE

Riepma, Klaas Alouis

1993-01-01

This dissertation discusses the effect of short time storage at different conditions on the strength and the specific BET surface area of lactose tablets. In addition, some aspects are studied of the consolidation and compaction properties of crystalline lactose fractions in heterogeneous systems. The crystalline lactose types used are: a-lactose monohydrate, anhydrous a-lactose, crystalline B-lactose and roller dried B-lactose. ... Zie: Summary

Description of climate, surface hydrology, and near-surface hydrogeology. Preliminary site description. Forsmark area - version 1.2

International Nuclear Information System (INIS)

Johansson, Per-Olof; Werner, Kent; Bosson, Emma; Berglund, Sten; Juston, John

2005-06-01

The present report is a background report describing the meteorological conditions and the modelling of surface hydrology and near-surface hydrogeology in support of the Forsmark version 1.2 SDM based on the data available in the Forsmark 1.2 ''data freeze'' (July 31, 2004). The area covered in the conceptual and descriptive modelling is characterised by a low relief and a small-scale topography. Almost the whole area is located below 20 m a s l (metres above sea level). The corrected mean annual precipitation is 600-650 mm and the mean annual evapotranspiration can be estimated to a little more than 400 mm, leaving approximately 200 mm x year-1 for runoff. Till is the dominating Quaternary deposit covering approximately 75% of the area. In most of the area, the till is sandy. Bedrock outcrops are frequent but cover only approximately 5% of the area. Direct groundwater recharge from precipitation is the dominant source of groundwater recharge. The small-scale topography implies that many local, shallow groundwater flow systems are formed in the Quaternary deposits, overlaying more large-scale flow systems associated with groundwater flows at greater depths. Groundwater level time series from wells in till and bedrock within the same areas show a considerably higher groundwater level in the till than in the bedrock. The sediment stratigraphy of lakes and wetlands is crucial for their function as discharge areas for groundwater. Comparisons between measured lake water levels and groundwater levels below and around lakes indicate that the lakes in some cases may act as sources of groundwater recharge. Specifically, observations from Lake Bolundsfjaerden and Lake Eckarfjaerden show that such conditions were at hand during the dry summer of 2003. However, whether the observed water level relations correspond to significant water fluxes depends also on the hydrogeological properties of the lake sediments and the underlying Quaternary deposits. ''Old'' water with high

Size-dependent proinflammatory effects of ultrafine polystyrene particles: a role for surface area and oxidative stress in the enhanced activity of ultrafines.

Science.gov (United States)

Brown, D M; Wilson, M R; MacNee, W; Stone, V; Donaldson, K

2001-09-15

Studies into the effects of ultrafine particles in the lung have shown adverse effects considered to be due in part to the particle size. Air pollution particles (PM(10)) are associated with exacerbations of respiratory disease and deaths from cardiovascular causes in epidemiological studies and the ultrafine fraction of PM(10) has been hypothesized to play an important role. The aim of the present study was to investigate proinflammatory responses to various sizes of polystyrene particles as a simple model of particles of varying size including ultrafine. In the animal model, we demonstrated that there was a significantly greater neutrophil influx into the rat lung after instillation of 64-nm polystyrene particles compared with 202- and 535-nm particles and this was mirrored in other parameters of lung inflammation, such as increased protein and lactate dehydrogenase in bronchoalveolar lavage. When surface area instilled was plotted against inflammation, these two variables were directly proportional and the line passed through zero. This suggests that surface area drives inflammation in the short term and that ultrafine particles cause a greater inflammatory response because of the greater surface area they possess. In vitro, we measured the changes in intracellular calcium concentration in mono mac 6 cells in view of the potential role of calcium as a signaling molecule. Calcium changes after particle exposure may be important in leading to proinflammatory gene expression such as chemokines. We demonstrated that only ultrafine polystyrene particles induced a significant increase in cytosolic calcium ion concentration. Experiments using dichlorofluorescin diacetate demonstrated greater oxidant activity of the ultrafine particles, which may explain their activity in these assays. There were significant increases in IL-8 gene expression in A549 epithelial cells after treatment with the ultrafine particles but not particles of other sizes. These findings suggest

Fabrication and photovoltaic performance of niobium doped TiO{sub 2} hierarchical microspheres with exposed {001} facets and high specific surface area

Energy Technology Data Exchange (ETDEWEB)

Liu, Yongqiang; Ran, Huili [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials, Zhengzhou University, Zhengzhou 450001 (China); Fan, Jiajie, E-mail: fanjiajie@zzu.edu.cn [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials, Zhengzhou University, Zhengzhou 450001 (China); Zhang, Xiaoli; Mao, Jing [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials, Zhengzhou University, Zhengzhou 450001 (China); Shao, Guosheng [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials, Zhengzhou University, Zhengzhou 450001 (China); Institute for Renewable Energy and Environmental Technologies, University of Bolton, Bolton BL3 5AB (United Kingdom)

2017-07-15

Highlights: • Nb-doped hierarchical TiO{sub 2} microsphere DSSCs show enhanced performance. • Nb{sup 5+} dopant replaces Ti{sup 4+} cation in TiO{sub 2} lattice. • Electrons transport was enhanced due to the down-shifted conduction band minimum. • Exposed (001) facets and high specific surface area allows high dye-loading. - Abstract: The niobium doped hierarchical anatase TiO{sub 2} microspheres, which are consist of a serried nano-thorns and plicate nano-ribbons with exposed {001} facets, were synthesized using hydrothermal method followed by heat treatment. The effects of niobium on the microstructures and photovoltaic performances of the dye-sensitized solar cells (DSSCs) were studied. The results revealed that Nb{sup 5+} doping replaces Ti{sup 4+} cations in TiO{sub 2} lattice, and the bandgap of the films varies with increasing Nb doping concentration because of the downshift of the conduction band minimum (CBM). The niobium-doped TiO{sub 2} DSSCs with moderate loadings show enhanced performance comparing with their pure TiO{sub 2} counterparts. Optimally, the conversion efficiency of the Nb-3.5 (Nb 3.5 mol%) DSSC is 4.99%. This is higher than that (4.39%) of pure TiO{sub 2} cells by 13.7%. This is due to the fact that the Nb-doped solar cells have increased the number of the photo-induced electrons because of their exposed (001) facets and higher specific surface area; and enhanced electrons collection and transport because of the downshifted CBM of the Nb-doped TiO{sub 2}. However, heavy Nb doping results in the decrease of the performance of the niobium-doped cells due to the excessive defects within the Nb-TiO{sub 2} samples resulting in enhanced charge recombination at defects.

Surface area loss and increased sphericity account for the splenic entrapment of subpopulations of Plasmodium falciparum ring-infected erythrocytes.

Directory of Open Access Journals (Sweden)

Innocent Safeukui

Full Text Available Ex vivo perfusion of human spleens revealed innate retention of numerous cultured Plasmodium falciparum ring-infected red blood cells (ring-iRBCs. Ring-iRBC retention was confirmed by a microsphiltration device, a microbead-based technology that mimics the mechanical filtering function of the human spleen. However, the cellular alterations underpinning this retention remain unclear. Here, we use ImageStream technology to analyze infected RBCs' morphology and cell dimensions before and after fractionation with microsphiltration. Compared to fresh normal RBCs, the mean cell membrane surface area loss of trophozoite-iRBCs, ring-iRBCs and uninfected co-cultured RBCs (uRBCs was 14.2% (range: 8.3-21.9%, 9.6% (7.3-12.2% and 3.7% (0-8.4, respectively. Microsphilters retained 100%, ∼50% and 4% of trophozoite-iRBCs, ring-iRBCs and uRBCs, respectively. Retained ring-iRBCs display reduced surface area values (estimated mean, range: 17%, 15-18%, similar to the previously shown threshold of surface-deficient RBCs retention in the human spleen (surface area loss: >18%. By contrast, ring-iRBCs that successfully traversed microsphilters had minimal surface area loss and normal sphericity, suggesting that these parameters are determinants of their retention. To confirm this hypothesis, fresh normal RBCs were exposed to lysophosphatidylcholine to induce a controlled loss of surface area. This resulted in a dose-dependent retention in microsphilters, with complete retention occurring for RBCs displaying >14% surface area loss. Taken together, these data demonstrate that surface area loss and resultant increased sphericity drive ring-iRBC retention in microsphilters, and contribute to splenic entrapment of a subpopulation of ring-iRBCs. These findings trigger more interest in malaria research fields, including modeling of infection kinetics, estimation of parasite load, and analysis of risk factors for severe clinical forms. The determination of the threshold of

Normalization in quantitative [18F]FDG PET imaging: the 'body surface area' may be a volume

International Nuclear Information System (INIS)

Laffon, Eric; Suarez, Kleydis; Berthoumieu, Yannick; Ducassou, Dominique; Marthan, Roger

2006-01-01

Non-invasive methods for quantifying [ 18 F]FDG uptake in tumours often require normalization to either body weight or body surface area (BSA), as a surrogate for [ 18 F]FDG distribution volume (DV). Whereas three dimensions are involved in DV and weight (assuming that weight is proportional to volume), only two dimensions are obviously involved in BSA. However, a fractal geometry interpretation, related to an allometric scaling, suggests that the so-called 'body surface area' may stand for DV. (note)

Clinical Aspects of Combination of Ceramic and Acrylic Occlusal Surfaces

Directory of Open Access Journals (Sweden)

Z. Ozhohan

2017-03-01

Full Text Available The objective of the research was to develop and substantiate the methods of constructing the occlusal surfaces when manufacturing aesthetic fixed restorations through the combination of different materials. Materials and methods. The study included 65 patients with ceramic and acrylic occlusal surfaces of aesthetic fixed dental prostheses. Group I included 21 patients with a combination of ceramic and acrylic occlusal surfaces. Group II included 22 patients with a combination of ceramic occlusal surfaces. Group III included 22 patients with a combination of acrylic occlusal surfaces. The patients were observed 3, 6 and 12 months after prosthetic repair. Results. The greatest increase in the occlusal contact surface area of fixed restorations was observed in Group I, that is, when combining dental prostheses with ceramic and acrylic occlusal surfaces. Considering uneven abrasion of the occlusal surfaces, we do not recommend to combine different materials when veneering the occlusal surface of the antagonistic teeth. Conclusions. This study demonstrated the important role of the correct combination of materials when veneering the occlusal surfaces. Physical and chemical properties of materials, namely the abrasion resistance play a significant role in the long-term denture functioning. The smallest increase in the occlusal contact surface area was observed in Group II when combining ceramic occlusal surfaces. It was due to a good abrasion resistance of ceramics as compared to acrylic resin as well as the presence of the glazed layer which prevents the premature abrasion of the occlusal surfaces of the antagonistic teeth due to lower surface roughness. The combination of acrylic resin and ceramics when constructing the occlusal surfaces of fixed restorations in Group I demonstrated the highest rate of the increase in the occlusal contact surface area – 9.93%. It was due to a low hardness of acrylic resin and its high surface roughness. In

Screening hydroxyapatite for cadmium and lead immobilization in aqueous solution and contaminated soil: The role of surface area.

Science.gov (United States)

Li, Hongying; Guo, Xisheng; Ye, Xinxin

2017-02-01

Hydroxyapatite (HAP) has been widely used to immobilize many cationic metals in water and soils. The specific reason why an increase in the surface area of HAP enhances cadmium (Cd) uptake, but has no effect on lead (Pb) uptake, is not clear. The aim of this study was to determine the factors causing the differences in sorption behavior between Cd and Pb by evaluating HAPs with different surface areas. We synthesized HAPs with two different surface areas, which were characterized by X-ray diffraction, N 2 adsorption, and scanning electron microscopy, and then evaluated them as sorbents for Cd and Pb removal by testing in single and binary systems. The sorption capacity of large surface area HAP (1.85mmol/g) for Cd in the single-metal system was higher than that of small surface area HAP (0.64mmol/g), but there were no differences between single- and binary-metal solutions containing Pb. After the Cd experiments, the HAP retained a stable structure and intact morphology, which promotes the accessibility of reactive sites for Cd. However, a newly formed precipitate covered the surface and blocked the channels in the presence of Pb, which reduced the number of potential adsorption sites on HAP for Cd and Pb. Remediation experiments using Cd- and Pb-contaminated soil produced similar results to the solution tests. These results indicate that alterations of the structure and morphology during the reaction is an important factor influencing metal sorption to HAP. Copyright © 2016. Published by Elsevier B.V.

Area-Specific Cell Stimulation via Surface-Mediated Gene Transfer Using Apatite-Based Composite Layers

Directory of Open Access Journals (Sweden)

Yushin Yazaki

2015-04-01

Full Text Available Surface-mediated gene transfer systems using biocompatible calcium phosphate (CaP-based composite layers have attracted attention as a tool for controlling cell behaviors. In the present study we aimed to demonstrate the potential of CaP-based composite layers to mediate area-specific dual gene transfer and to stimulate cells on an area-by-area basis in the same well. For this purpose we prepared two pairs of DNA–fibronectin–apatite composite (DF-Ap layers using a pair of reporter genes and pair of differentiation factor genes. The results of the area-specific dual gene transfer successfully demonstrated that the cells cultured on a pair of DF-Ap layers that were adjacently placed in the same well showed specific gene expression patterns depending on the gene that was immobilized in theunderlying layer. Moreover, preliminary real-time PCR results indicated that multipotential C3H10T1/2 cells may have a potential to change into different types of cells depending on the differentiation factor gene that was immobilized in the underlying layer, even in the same well. Because DF-Ap layers have a potential to mediate area-specific cell stimulation on their surfaces, they could be useful in tissue engineering applications.

Surface area and chemical reactivity characteristics of uranium metal corrosion products

International Nuclear Information System (INIS)

Totemeier, T. C.

1998-01-01

The results of an initial characterization of hydride-containing corrosion products from uranium metal Zero Power Physics Reactor (ZPPR) fuel plates are presented. Sorption analyses using the BET method with a Kr adsorbate were performed to measure the specific areas of corrosion product samples. The specific surface areas of the corrosion products varied from 0.66 to 1.01 m 2 /g. The reactivity of the products in Ar-9%O 2 and Ar-20%O 2 were measured at temperatures between 35 C and 150 C using a thermo-gravimetric analyzer. Ignition of the products occurred at temperatures of 150 C and above. The oxidation rates below ignition were comparable to rates observed for uranium metal

Human cortical areas involved in perception of surface glossiness.

Science.gov (United States)

Wada, Atsushi; Sakano, Yuichi; Ando, Hiroshi

2014-09-01

Glossiness is the visual appearance of an object's surface as defined by its surface reflectance properties. Despite its ecological importance, little is known about the neural substrates underlying its perception. In this study, we performed the first human neuroimaging experiments that directly investigated where the processing of glossiness resides in the visual cortex. First, we investigated the cortical regions that were more activated by observing high glossiness compared with low glossiness, where the effects of simple luminance and luminance contrast were dissociated by controlling the illumination conditions (Experiment 1). As cortical regions that may be related to the processing of glossiness, V2, V3, hV4, VO-1, VO-2, collateral sulcus (CoS), LO-1, and V3A/B were identified, which also showed significant correlation with the perceived level of glossiness. This result is consistent with the recent monkey studies that identified selective neural response to glossiness in the ventral visual pathway, except for V3A/B in the dorsal visual pathway, whose involvement in the processing of glossiness could be specific to the human visual system. Second, we investigated the cortical regions that were modulated by selective attention to glossiness (Experiment 2). The visual areas that showed higher activation to attention to glossiness than that to either form or orientation were identified as right hV4, right VO-2, and right V3A/B, which were commonly identified in Experiment 1. The results indicate that these commonly identified visual areas in the human visual cortex may play important roles in glossiness perception. Copyright © 2014. Published by Elsevier Inc.

Temporal variability of surface runoff due to cropping systems in cultivated catchment areas: Use of the DIAR model for the assessment of environmental public policies in the Pays de Caux (France).

Science.gov (United States)

Martin, P; Joannon, A; Piskiewicz, N

2010-01-01

This article proposes the use of a new model, DIAR (Diagnostic Agronomique du Ruissellement, or Agronomic Assessment of Runoff), for the prediction of the timing of the risk of runoff. DIAR is dedicated to loamy soils which are very sensitive to surface crusting, leading to runoff, soil erosion and muddy flows. The approach is proposed for the north-western European loess belt regions where muddy flows severely impact human activities. The likelihood of runoff is assessed from the sequence of soil surface states generated by cultivation practices. DIAR is based on the calculation of curve number values, for each stage of the soil-surface-state sequence, for calculating runoff for each of these stages. In this study, DIAR is applied to a catchment of 912 ha, cultivated by 26 farmers in the Pays de Caux (Normandy, France) where infrastructures located at the outlet have been damaged several times by muddy flows. Local public authorities involved in reducing muddy flows are eager to limit the agricultural upstream runoff by extending the planting of mustard as a winter cover crop. We tested the efficiency of such a policy on the reduction of the mean runoff. We also tested the year-to-year variability of this efficiency using the acreages of four successive years (1999-2000 to 2002-2003). Finally, the cost-efficiency of the policy was also considered. Though we used the same weather scenario, the initial situation (without much mustard cover) showed a wide year-to-year variation in the total runoff. This variation can be associated with the structure of the farms that cultivate the catchment (Utilised Agricultural Area (UAA) of each farm and percentage of this UAA inside the catchment). Our results showed that the widespread planting of winter cover crops could reduce the runoff by 10-20% compared with the initial situation (depending on the year), and also reduce the year-to-year variability of runoff. For each of the 4 tested years, the cost of the infiltrated m(3

Response of three instruments devoted to surface-area for monodisperse and polydisperse aerosols in molecular and transition regimes

International Nuclear Information System (INIS)

Bau, Sebastien; Witschger, Olivier; Gensdarmes, Francois; Thomas, Dominique

2011-01-01

An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment. Indeed, our understanding of the hazards, the actual exposures in the workplace and the limits of engineering controls and personal protective equipment with regard to NP are still under development. Several studies have already identified surface-area as an important determinant of low solubility nanoparticles toxicity. As a consequence, the concept that surface-area could be a relevant metric for characterizing exposure to low solubility airborne NP has been proposed [1]. To provide NP surface-area concentration, some direct-reading instruments have been designed, based on diffusion charging. The actual available instruments providing airborne NP surface-area concentration are studied in this work: LQ1-DC (Matter Engineering), AeroTrak T M 9000 (TSI) and NSAM (TSI model 3550). Their performances regarding monodisperse carbon NP have been investigated by Bau et al.. This work aims at completing the instruments characterization regarding monodisperse NP of other chemical composition (aluminium, copper, silver) and studying their performances against polydisperse aerosols of NP.

Response of three instruments devoted to surface-area for monodisperse and polydisperse aerosols in molecular and transition regimes

Energy Technology Data Exchange (ETDEWEB)

Bau, Sebastien; Witschger, Olivier [Institut National de Recherche et de Securite (INRS), Laboratoire de Metrologie des Aerosols, Rue du Morvan, CS 60027, 54519 Vandoeuvre Cedex (France); Gensdarmes, Francois [Institut de Radioprotection et de Surete Nucleaire (IRSN), Laboratoire de Physique et de Metrologie des Aerosols, BP 68, 91192 Gif-sur-Yvette (France); Thomas, Dominique, E-mail: sebastien.bau@inrs.fr [Laboratoire Reactions et Genie des Procedes (LRGP), groupe SAFE, 1 rue Grandville, BP 20041, 54001 Nancy Cedex (France)

2011-07-06

An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment. Indeed, our understanding of the hazards, the actual exposures in the workplace and the limits of engineering controls and personal protective equipment with regard to NP are still under development. Several studies have already identified surface-area as an important determinant of low solubility nanoparticles toxicity. As a consequence, the concept that surface-area could be a relevant metric for characterizing exposure to low solubility airborne NP has been proposed [1]. To provide NP surface-area concentration, some direct-reading instruments have been designed, based on diffusion charging. The actual available instruments providing airborne NP surface-area concentration are studied in this work: LQ1-DC (Matter Engineering), AeroTrak{sup TM} 9000 (TSI) and NSAM (TSI model 3550). Their performances regarding monodisperse carbon NP have been investigated by Bau et al.. This work aims at completing the instruments characterization regarding monodisperse NP of other chemical composition (aluminium, copper, silver) and studying their performances against polydisperse aerosols of NP.

Application of stereological methods to estimate post-mortem brain surface area using 3T MRI

DEFF Research Database (Denmark)

Furlong, Carolyn; García-Fiñana, Marta; Puddephat, Michael

2013-01-01

The Cavalieri and Vertical Sections methods of design based stereology were applied in combination with 3 tesla (i.e. 3T) Magnetic Resonance Imaging (MRI) to estimate cortical and subcortical volume, area of the pial surface, area of the grey-white matter boundary, and thickness of the cerebral...

An Experimental Study of the Noise Due to Traffic in a Congested Urban Area

Science.gov (United States)

Sangeetha, M.; Sankar, P.

2016-03-01

Noise pollution in an urban environment is an issue of serious concern in the major cities of India. There are various factors that contribute to the increase of noise levels in urban areas. The intensity of traffic is one of the factors which contributes to a drastic increase in environmental noise. The management of noise pollution has to be considered in the decision making process. In this paper, an attempt is made to study the existing noise level due to the traffic in Velachery which is declared as a sensitive area by the Ministry of Environment and Forestry (MoEF). The noise level data is collected using the MS6710 digital sound meter. The Custic simulation software version 3.2 is used for finding the propagation of noise. The spatial patterns of measurement were also calculated, in the sub-urban area of Velachery, Chennai, Tamilnadu, India. A means of transmitting this data to vehicles moving in the area, through a wireless medium is simulated using NCTUns 6.0 (network simulator), to enable drivers to understand the environmental conditions. A hardware was also designed which can be used to transmit and receive the noise data using the Zigbee module. A noise transmitting station is placed at a junction, so that it can transmit this noise data to the receivers which are fitted inside the vehicles.

Variation of solubility, biokinetics and dose coefficient of industrial uranium oxides according to the specific surface area

International Nuclear Information System (INIS)

Chazel, V.; Houpert, P.; Ansorbolo, E.; Henge-Napoli, M.H.; Paquet, F.

2000-01-01

The in vitro solubility, absorption to blood, lung retention and dose coefficient of industrial UO 2 samples were studied as a function of the specific surface area (SSA) of the particles. An in vitro study has been carried out on two samples of industrial UO 4 to compare the results with those obtained with UO 2 . Ten UO 2 samples supplied by different fuel factories or research laboratories, presented specific surface areas from 1.00 to 4.45 m 2 .g -1 . The wide range of values of SSA was due to the different conditions of fabrication. Dissolution tests in cell culture medium made on these ten samples have shown that the solubility increased 2.5-fold when the SSA increased 1.7-fold. The same tendency has been found for UO 4 , a soluble compound, and for U 3 O 8 , a moderately soluble compound. Four in vivo experiments carried out on rats by intratracheal instillation of dust suspensions of UO 2 , have highlighted the decrease in lung retention and the increase of absorption to blood with the SSA. The experimental absorption parameters calculated from the in vivo data allowed specific dose coefficients to be obtained which decreased from 6.6 to 4.3 μSv.Bq -1 when the SSA increased from 1.60 to 3.08 m 2 .g -1 . Thus, the medical monitoring of workers at the workplace has to take into account any change in the fabrication process of the uranium compound which can affect the physiochemical properties and consequently the dose coefficient. (author)

Hydrogen-terminated mesoporous silicon monoliths with huge surface area as alternative Si-based visible light-active photocatalysts

KAUST Repository

Li, Ting

2016-07-21

Silicon-based nanostructures and their related composites have drawn tremendous research interest in solar energy storage and conversion. Mesoporous silicon with a huge surface area of 400-900 m2 g-1 developed by electrochemical etching exhibits excellent photocatalytic ability and stability after 10 cycles in degrading methyl orange under visible light irradiation, owing to its unique mesoporous network, abundant surface hydrides and efficient light harvesting. This work showcases the profound effects of surface area, crystallinity, pore topology on charge migration/recombination and mass transportation. Therein the ordered 1D channel array has outperformed the interconnected 3D porous network by greatly accelerating the mass diffusion and enhancing the accessibility of the active sites on the extensive surfaces. © 2016 The Royal Society of Chemistry.

THE EFFECT OF STORAGE AT AMBIENT HUMIDITY ON THE BET-SPECIFIC SURFACE-AREA OF TABLETS COMPACTED FROM DIFFERENT MATERIALS

NARCIS (Netherlands)

RIEPMA, KA; DEKKER, BG; JAGER, RS; ELBERSE, PA; LERK, CF

1993-01-01

Tablets compacted from both water soluble and water insoluble particulate solids showed no change in BET-specific surface area when transferred immediately after ejection from the die in a dry atmosphere. Storage at ambient humidity resulted in an irreversible decrease in surface area, caused by

Impact of membrane lung surface area and blood flow on extracorporeal CO2 removal during severe respiratory acidosis.

Science.gov (United States)

Karagiannidis, Christian; Strassmann, Stephan; Brodie, Daniel; Ritter, Philine; Larsson, Anders; Borchardt, Ralf; Windisch, Wolfram

2017-12-01

Veno-venous extracorporeal CO 2 removal (vv-ECCO 2 R) is increasingly being used in the setting of acute respiratory failure. Blood flow rates through the device range from 200 ml/min to more than 1500 ml/min, and the membrane surface areas range from 0.35 to 1.3 m 2 . The present study in an animal model with similar CO 2 production as an adult patient was aimed at determining the optimal membrane lung surface area and technical requirements for successful vv-ECCO 2 R. Four different membrane lungs, with varying lung surface areas of 0.4, 0.8, 1.0, and 1.3m 2 were used to perform vv-ECCO 2 R in seven anesthetized, mechanically ventilated, pigs with experimentally induced severe respiratory acidosis (pH 7.0-7.1) using a 20Fr double-lumen catheter with a sweep gas flow rate of 8 L/min. During each experiment, the blood flow was increased stepwise from 250 to 1000 ml/min. Amelioration of severe respiratory acidosis was only feasible when blood flow rates from 750 to 1000 ml/min were used with a membrane lung surface area of at least 0.8 m 2 . Maximal CO 2 elimination was 150.8 ml/min, with pH increasing from 7.01 to 7.30 (blood flow 1000 ml/min; membrane lung 1.3 m 2 ). The membrane lung with a surface of 0.4 m 2 allowed a maximum CO 2 elimination rate of 71.7 mL/min, which did not result in the normalization of pH, even with a blood flow rate of 1000 ml/min. Also of note, an increase of the surface area above 1.0 m 2 did not result in substantially higher CO 2 elimination rates. The pressure drop across the oxygenator was considerably lower (respiratory acidosis, irrespective of the surface area of the membrane lung being used. The converse was also true, low surface membrane lungs (0.4 m 2 ) were not capable of completely correcting severe respiratory acidosis across the range of blood flows used in this study.

Structural and surface changes in glassy carbon due to strontium implantation and heat treatment

Science.gov (United States)

Odutemowo, O. S.; Malherbe, J. B.; Prinsloo, L. C.; Njoroge, E. G.; Erasmus, R.; Wendler, E.; Undisz, A.; Rettenmayr, M.

2018-01-01

There are still questions around the microstructure of glassy carbon (GC), like the observation of the micropores. These were proposed to explain the low density of GC. This paper explains the effect of ion bombardment (200 keV Sr+, 1 × 1016 Sr+/cm2 at RT) on the microstructure of GC. TEM and AFM show that micropores in pristine GC are destroyed leading to densification of GC from 1.42 g/cm3 to 2.03 g/cm3. The amorphisation of glassy carbon was also not complete with graphitic strands embedded within the GC. These were relatively few, as Raman analysis showed that the Sr implantation resulted in a typical amorphous Raman spectrum. Annealing of the sample at 900 °C only resulted in a slight recovery of the GC structure. AFM and SEM analysis showed that the surface of the sample became rougher after Sr implantation. The roughness increased after the sample was annealed at 600 °C due to segregation of Sr towards the surface of the GC. SEM measurements of a sample with both implanted and un-implanted edges after annealing at 900 °C, showed that the high temperature heat treatment did not affect the surface topography of un-irradiated GC.

Fabrication of a Horizontal and a Vertical Large Surface Area Nanogap Electrochemical Sensor

Directory of Open Access Journals (Sweden)

Jules L. Hammond

2016-12-01

Full Text Available Nanogap sensors have a wide range of applications as they can provide accurate direct detection of biomolecules through impedimetric or amperometric signals. Signal response from nanogap sensors is dependent on both the electrode spacing and surface area. However, creating large surface area nanogap sensors presents several challenges during fabrication. We show two different approaches to achieve both horizontal and vertical coplanar nanogap geometries. In the first method we use electron-beam lithography (EBL to pattern an 11 mm long serpentine nanogap (215 nm between two electrodes. For the second method we use inductively-coupled plasma (ICP reactive ion etching (RIE to create a channel in a silicon substrate, optically pattern a buried 1.0 mm × 1.5 mm electrode before anodically bonding a second identical electrode, patterned on glass, directly above. The devices have a wide range of applicability in different sensing techniques with the large area nanogaps presenting advantages over other devices of the same family. As a case study we explore the detection of peptide nucleic acid (PNA−DNA binding events using dielectric spectroscopy with the horizontal coplanar device.

Water treatment strategy for underground and surface waters in order to reduce the hydro-network contamination due to close out of a uranium mining area in Romania

International Nuclear Information System (INIS)

Georgescu, D.; Radulescu, C.

1999-01-01

Under the present circumstances, in correlation with the national nuclear program and strategy, it is foreseen to stop the exploitation activities in two important uranium mining areas from Romania. This close-out action is involving a number of technical decisions for environmental restoration. Reduction of waters radioactive contamination in these zones, both during the operating period and after the closeout period, is one of the main components of the environment rehabilitation strategy. In this paper there are presented the today situation and the program foreseen for ground and surface water treatment at an uranium mining unit situated in the SW side of Romania, program based on the results of our own research carried out to decrease the content of pollutant radioactive elements. (author)

Nonlinear radiation of waves at combination frequencies due to radiation-surface wave interaction in plasmas

International Nuclear Information System (INIS)

El Naggar, I.A.; Hussein, A.M.; Khalil, Sh.M.

1992-09-01

Electromagnetic waves radiated with combination frequencies from a semi-bounded plasma due to nonlinear interaction of radiation with surface wave (both of P-polarization) has been investigated. Waves are radiated both into vacuum and plasma are found to be P-polarized. We take into consideration the continuity at the plasma boundary of the tangential components of the electric field of the waves. The case of normal incidence of radiation and rarefield plasma layer is also studied. (author). 7 refs