WorldWideScience

Sample records for surface seawater measurements

  1. Surface resistivity/conductivity of oxide–hydroxide compounds in inhibited seawater by optical interferometry

    Directory of Open Access Journals (Sweden)

    Khaled Habib

    2016-09-01

    Full Text Available Optical interferometry techniques were used to measure the surface resistivity/conductivity of carbon steel samples in blank seawater and in seawater with different concentrations of a corrosion inhibitor, without any physical contact. The measurement of the surface resistivity/conductivity of carbon steel samples was carried out in blank seawater and in seawater with a concentration range of 5–20 ppm of RA-41 corrosion inhibitor, at room temperature. In this investigation, the real-time holographic interferometry was carried out to measure the thickness of anodic dissolved layer or the total thickness, Utotal, of the formed oxide layer of carbon steel samples during the alternating current (AC impedance of the samples in blank seawater and in 5–20 ppm RA-41 inhibited seawater, respectively. In other words, the surface resistivity/conductivity of carbon steel samples was determined simultaneously by holographic interferometry, an electromagnetic method, and by the Electrochemical Impedance (E.I spectroscopy, an electronic method. In addition, a mathematical model was derived in order to correlate between the AC impedance (resistance and to the surface (orthogonal displacement of the surface of the samples in solutions.

  2. Super-hydrophobic surfaces improve corrosion resistance of copper in seawater

    International Nuclear Information System (INIS)

    Liu, Tao; Yin, Yansheng; Chen, Shougang; Chang, Xueting; Cheng, Sha

    2007-01-01

    Pretreated by a n-tetradecanoic acid (CH 3 (CH 2 ) 12 COOH) etch, the super-hydrophobic film was formed on the fresh copper surface. The film structure was probed with contact angle measurement and scanning electron microscopy (SEM). The results suggest that the structure of the film is similar to haulm or flower and the seawater contact angle is larger than 150 o . Moreover, the corrosion resistance of bare and modified samples in seawater were investigated by cyclic voltammograms (CV) and electrochemical impedance spectroscopy (EIS). Experimental results show that the corrosion rate of Cu with super-hydrophobic surface decreases dramatically because of its special microstructure

  3. Super-hydrophobic surface treatment as corrosion protection for aluminum in seawater

    Energy Technology Data Exchange (ETDEWEB)

    He Tian; Wang Yuanchao; Zhang Yijian; Lv Qun; Xu Tugen [College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 310036 (China); Liu Tao [Institute of Ocean Materials and Engineering, Shanghai Maritime University, Shanghai 200135 (China)], E-mail: yys2003ouc@163.com

    2009-08-15

    'Underwater super-hydrophobic' surface applied in the corrosion protection was prepared by melting myristic acid (CH{sub 3}(CH{sub 2}){sub 12}COOH) adsorbed onto the anodized aluminum. The static contact angle for seawater on the surface was measured to be 154{sup o}. The surface structure and composition were then characterized by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectrum (EDS) and atomic force microscope (AFM). The electrochemical measurements showed that the super-hydrophobic surface significantly improved the corrosion resistance of aluminum in sterile seawater. In addition, the mechanism of the underwater super-hydrophobic surface applied in the corrosion resistance was discussed using a schematic.

  4. Global Cr-isotope distributions in surface seawater and incorporation of Cr isotopes into carbonate shells

    DEFF Research Database (Denmark)

    Paulukat, Cora Stefanie; Frei, Robert; Vögelin, Andrea Regula

    In this study we present the Cr-isotope composition of surface seawater from several locations worldwide. In addition to the samples from the oceans (Atlantic Ocean, Pacific Ocean, Southern Ocean and Artic Ocean) we analysed water samples from areas with a more limited water exchange (Mediterranean...... Sea, Baltic Sea, Øresund and Kattegat). The long residence time of Cr (7,000 to 40,000 years) [1,2,3] relative to the ocean mixing time (1,000 to 2,000 years) [4] could lead to the expectation that the Cr concentration and Cr-isotope distribution are homogeneous in the oceans. However, our seawater...... observed a negative correlation between the Cr-isotope composition and the Cr concentration. Exceptions are samples from the Baltic Sea/Øresund, which are isotopically light despite low Cr concentrations (~0.1-0.2 ppb). In addition to the seawater data, we measured Cr isotopes in modern biologically...

  5. Leaching heavy metals from the surface soil of reclaimed tidal flat by alternating seawater inundation and air drying.

    Science.gov (United States)

    Guo, Shi-Hong; Liu, Zhen-Ling; Li, Qu-Sheng; Yang, Ping; Wang, Li-Li; He, Bao-Yan; Xu, Zhi-Min; Ye, Jin-Shao; Zeng, Eddy Y

    2016-08-01

    Leaching experiments were conducted in a greenhouse to simulate seawater leaching combined with alternating seawater inundation and air drying. We investigated the heavy metal release of soils caused by changes associated with seawater inundation/air drying cycles in the reclaimed soils. After the treatment, the contents of all heavy metals (Cd, Pb, Cr, and Cu), except Zn, in surface soil significantly decreased (P seawater inundation enhanced the release of heavy metals. Measurement of diffusive gradients in thin films indicated that seawater inundation significantly increased the re-mobility of heavy metals. During seawater inundation, iron oxide reduction induced the release of heavy metals in the reducible fraction. Decomposition of organic matter, and complexation with dissolved organic carbon decreased the amount of heavy metals in the oxidizable fraction. Furthermore, complexation of chloride ions and competition of cations during seawater inundation and/or leaching decreased the levels of heavy metals in the exchangeable fraction. By contrast, air drying significantly enhanced the concentration of heavy metals in the exchangeable fraction. Therefore, the removal of heavy metals in the exchangeable fraction can be enhanced during subsequent leaching with seawater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Spectral properties of natural and oil polluted Baltic seawater — results of measurements and modelling

    Science.gov (United States)

    Drozdowska, V.; Freda, W.; Baszanowska, E.; Rudź, K.; Darecki, M.; Heldt, J. R.; Toczek, H.

    2013-10-01

    Seawater in addition to natural components such as living and non-living organic matter contains also components artificially introduced into the marine environment, such as oil substances. These components, present in the surface layer of the sea, can significantly affect radiative transfer processes. Therefore, taking into account these processes in remote sensing measurements can improve assessment of the environment. To improve local seawater optical models, it is necessary to measure the luminescence properties of all components of seawater as well as the water leaving radiance values. Additionally, substances which form the surface microlayer (surfactants — surface active agents) can affect both the dynamic characteristics of the fluxes (in particular the gas exchange and marine aerosol production) as well as inherent optical properties of surface seawater. This paper contains both the results of research focused on introducing of an efficient method for identifying oils by their fluorescence spectra as well as a marine experiment on the identification of luminescent properties of surfactants — sampled in different regions of the Baltic Sea. Moreover, the aim of the presented study is to assess the impact of the oil emulsion to spectral water leaving signal. Those results are obtained both from running Monte Carlo radiative transfer code and from approximated formulas.

  7. Concentrations and activity ratios of 228Ra and 226Ra in surface seawater along the Pacific coast of Japan

    International Nuclear Information System (INIS)

    Ohta, T.; Mahara, Y.; Kubota, T.; Sato, J.; Gamo, T.

    2011-01-01

    We measured the 228 Ra/ 226 Ra activity ratios in surface seawater along the Pacific coast of Japan at five ports around the island of Izu-Oshima (n = 29), at Atami in Sagami Bay (n = 13), and at Umizuri Park in Tokyo Bay (n = 14). We also conducted these measurements along a transect from the open Pacific Ocean across the Kuroshio to the mouth of Tokyo Bay (n = 7). The activity ratios decreased with increasing salinity of the sampling sites. The 228 Ra/ 226 Ra activity ratios in surface seawater along the coast gradually decreased after at the end of autumn and were lowest in winter and the beginning of spring. The surface salinity along the coast decreased from summer into autumn and increased from winter to the beginning of spring. The activity ratios decreased with the increase of salinity. The variation in activity ratios at the three coastal sites is possibly caused by differing contributions of surface seawater from the Kuroshio and surrounding open ocean. The different patterns and ranges of variation in the 228 Ra/ 226 Ra activity ratios in surface seawater at Izu-Oshima, Atami, and Umizuri Park may reflect both the amount of water from the Kuroshio and vicinity, and the local bathymetry, because continental shelf sediment is the source of Ra isotopes in surface seawater. (orig.)

  8. Vertical variability of seawater DMS in the South Pacific Ocean and its implication for atmospheric and surface seawater DMS.

    Science.gov (United States)

    Lee, Gangwoong; Park, Jooyoung; Jang, Yuwoon; Lee, Meehye; Kim, Kyung-Ryul; Oh, Jae-Ryoung; Kim, Dongseon; Yi, Hi-Il; Kim, Tong-Yup

    2010-02-01

    Shipboard measurements of atmospheric dimethylsulfide (DMS) and sea surface water DMS were performed aboard the R/V Onnuri across the South Pacific from Santiago, Chile to Fiji in February 2000. Hydrographic profiles of DMS, dissolved dimethylsulfoniopropionate (DMSP(d)), and particulate DMSP(p) in the upper 200m were obtained at 16 stations along the track. Atmospheric and sea surface water DMS concentrations ranged from 3 to 442pptv and from 0.1 to 19.9nM, respectively; the mean values of 61pptv and 2.1nM, respectively, were comparable to those from previous studies in the South Pacific. The South Pacific Gyre was distinguished by longitudinal-vertical distributions of DMS, DMSP(d), and DMSP(p), which was thought to be associated with the characteristic modification of biological activities that occurs mainly due to significant change in water temperature. The averaged DMS maximum appeared at 40m depth, whereas DMSP(p) and DMSP(d) maxima coincided with that of dissolved oxygen content at 60-80m. The sea-to-air fluxes of DMS were estimated to be 0.4-11.3micromold(-1)m(-2) (mean=2.8micromold(-1)m(-2)). A fairly good correlation between atmospheric DMS and sea-to-air DMS flux indicated that atmospheric DMS concentration was more sensitive to change in physical parameters than its photochemical removal process or surface seawater DMS concentrations.

  9. New Dielectric Measurement Data to Determine the Permittivity of Seawater at 1.4313 Hz

    Science.gov (United States)

    Lang, R.; Zhou, Y.; Utku, C.; Levine, D.

    2012-01-01

    This paper describes the new measurements - made in 2010-2011 - of the dielectric constant of seawater at 1.413 GHz using a resonant cavity technique. The purpose of these measurements is to develop an accurate relationship concerning the dependence of the dielectric constant of seawater on temperature and salinity for use by the Aquarius inversion algorithm. Aquarius is a NASA/CONAE satellite mission launched in June of 2011 with the primary mission of measuring global sea surface salinity with a 1.413 GHz radiometer to an accuracy of 0.2 psu. A brass microwave cavity resonant at 1.413 GHz has been used to measure the dielectric constant of seawater. The seawater is introduced into the cavity through a capillary glass tube having an inner diameter of 0.1 mm. The change of resonant frequency and the cavity Q value are used to determine the real and imaginary parts of the dielectric constant of seawater. Measurements are automated with Visual Basic software developed at the George Washington University. In this paper, new results from measurements made since September 2010 will be presented for salinities of 30, 35 and 38 psu with a temperature range of 0 C to 35 C in intervals of 5 C. These measurements are more accurate than earlier measurements made in 2008. The new results will be compared to the Klein-Swift (KS) and Meissner-Wentz (MW) model functions. The importance of an accurate model function will be illustrated by using these model functions to invert the Aquarius brightness temperature to retrieve the salinity values. The salinity values will be compared to co-located in situ data collected by Argo buoys.

  10. Solid State Sensor for Simultaneous Measurement of Total Alkalinity and pH of Seawater.

    Science.gov (United States)

    Briggs, Ellen M; Sandoval, Sergio; Erten, Ahmet; Takeshita, Yuichiro; Kummel, Andrew C; Martz, Todd R

    2017-09-22

    A novel design is demonstrated for a solid state, reagent-less sensor capable of rapid and simultaneous measurement of pH and Total Alkalinity (A T ) using ion sensitive field effect transistor (ISFET) technology to provide a simplified means of characterization of the aqueous carbon dioxide system through measurement of two "master variables": pH and A T . ISFET-based pH sensors that achieve 0.001 precision are widely used in various oceanographic applications. A modified ISFET is demonstrated to perform a nanoliter-scale acid-base titration of A T in under 40 s. This method of measuring A T , a Coulometric Diffusion Titration, involves electrolytic generation of titrant, H + , through the electrolysis of water on the surface of the chip via a microfabricated electrode eliminating the requirement of external reagents. Characterization has been performed in seawater as well as titrating individual components (i.e., OH - , HCO 3 - , CO 3 2- , B(OH) 4 - , PO 4 3- ) of seawater A T . The seawater measurements are consistent with the design in reaching the benchmark goal of 0.5% precision in A T over the range of seawater A T of ∼2200-2500 μmol kg -1 which demonstrates great potential for autonomous sensing.

  11. Oceanographic profile chlorophyll, nutrients and other measurements collected using surface seawater intake from the Caribbean, Pacific and Atlantic Ocean from 1999 - 2002 (NODC Accession 0001009)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A set of phytoplankton pigment measurements collected on eight quarterly transects from France to New Caledonia is analyzed in order to identify the main assemblages...

  12. Metrological traceability of carbon dioxide measurements in atmosphere and seawater

    Science.gov (United States)

    Rolle, F.; Pessana, E.; Sega, M.

    2017-05-01

    The accurate determination of gaseous pollutants is fundamental for the monitoring of the trends of these analytes in the environment and the application of the metrological concepts to this field is necessary to assure the reliability of the measurement results. In this work, an overview of the activity carried out at Istituto Nazionale di Ricerca Metrologica to establish the metrological traceability of the measurements of gaseous atmospheric pollutants, in particular of carbon dioxide (CO2), is presented. Two primary methods, the gravimetry and the dynamic dilution, are used for the preparation of reference standards for composition which can be used to calibrate sensors and analytical instrumentation. At present, research is carried out to lower the measurement uncertainties of the primary gas mixtures and to extend their application to the oceanic field. The reason of such investigation is due to the evidence of the changes occurring in seawater carbonate chemistry, connected to the rising level of CO2 in the atmosphere. The well established activity to assure the metrological traceability of CO2 in the atmosphere will be applied to the determination of CO2 in seawater, by developing suitable reference materials for calibration and control of the sensors during their routine use.

  13. Accurate Measurements of the Dielectric Constant of Seawater at L Band

    Science.gov (United States)

    Lang, Roger; Zhou, Yiwen; Utku, Cuneyt; Le Vine, David

    2016-01-01

    This paper describes measurements of the dielectric constant of seawater at a frequency of 1.413 GHz, the center of the protected band (i.e., passive use only) used in the measurement of sea surface salinity from space. The objective of the measurements is to accurately determine the complex dielectric constant of seawater as a function of salinity and temperature. A resonant cylindrical microwave cavity in transmission mode has been employed to make the measurements. The measurements are made using standard seawater at salinities of 30, 33, 35, and 38 practical salinity units over a range of temperatures from 0 degree C to 35 degree C in 5 degree C intervals. Repeated measurements have been made at each temperature and salinity. Mean values and standard deviations are then computed. The total error budget indicates that the real and imaginary parts of the dielectric constant have a combined standard uncertainty of about 0.3 over the range of salinities and temperatures considered. The measurements are compared with the dielectric constants obtained from the model functions of Klein and Swift and those of Meissner and Wentz. The biggest differences occur at low and high temperatures.

  14. A coastal surface seawater analyzer for nitrogenous nutrient mapping

    Science.gov (United States)

    Masserini, Robert T.; Fanning, Kent A.; Hendrix, Steven A.; Kleiman, Brittany M.

    2017-11-01

    Satellite-data-based modeling of chlorophyll indicates that ocean waters in the mesosphere category are responsible for the majority of oceanic net primary productivity. Coastal waters, which frequently have surface chlorophyll values in the mesosphere range and have strong horizontal chlorophyll gradients and large temporal variations. Thus programs of detailed coastal nutrient surveys are essential to the study of the dynamics of oceanic net primary productivity, along with land use impacts on estuarine and coastal ecosystems. The degree of variability in these regions necessitates flexible instrumentation capable of near real-time analysis to detect and monitor analytes of interest. This work describes the development of a portable coastal surface seawater analyzer for nutrient mapping that can simultaneously elucidate with high resolution the distribution of nitrate, nitrite, and ammonium - the three principal nitrogenous inorganic nutrients in coastal systems. The approach focuses on the use of pulsed xenon flash lamps to construct an analyzer which can be adapted to any automated chemistry with fluorescence detection. The system has two heaters, on-the-fly standardization, on-board data logging, an independent 24 volt direct current power supply, internal local operating network, a 12 channel peristaltic pump, four rotary injection/selection valves, and an intuitive graphical user interface. Using the methodology of Masserini and Fanning (2000) the detection limits for ammonium, nitrite, and nitrate plus nitrite were 11, 10, and 22 nM, respectively. A field test of the analyzer in Gulf of Mexico coastal waters demonstrated its ability to monitor and delineate the complexity of inorganic nitrogen nutrient enrichments within a coastal system.

  15. Distribution of 137Cs in surface seawater and sediment around Sabahs Sulu-Sulawesi Sea

    International Nuclear Information System (INIS)

    Mohd Izwan Abdul Aziz; Ahmad Sanadi Abu Bakar; Yii, Mei Wo; Nurrul Assyikeen Jaffary; Zaharudin Ahmad

    2010-01-01

    The studies on distribution of 137 Cs in surface seawater and sediment around Sabahs Sulu-Sulawesi Sea were carried out during Ekspedisi Pelayaran Saintifik Perdana (EPSP) in July 2009. About sixteen and twenty five sampling locations were identified for surface seawater and sediment respectively in Sabahs Sulu-Sulawesi Sea. Large volumes of seawater samples are collected and co-precipitation technique was employed to concentrate cesium content before known amounts of 134 Cs tracer were added as yield determinant. Grab sampler were used to collect surface sediment sample. The caesium precipitate and sediment were dried and finely ground before counted using gamma-ray spectrometry system at 661 keV. The activity of 137 Cs was found in surface seawater and sediment to be in the range 1.73 Bq/ m 3 to 5.50 Bq/ m 3 and 1.15 Bq/ kg to 4.53 Bq/ kg respectively. (author)

  16. Measurement of the Dielectric Constant of Seawater at L-Band: Techniques and Measurements

    Science.gov (United States)

    Lang, R.; Utku, C.; Tarkocin, Y.; LeVine, D.

    2009-01-01

    Satellite instruments, that will monitor salinity from space in the near future, require an accurate relationship between salinity/temperature and seawater dielectric constant. This paper will review measurements that were made of the dielectric constant of seawater during the past several years. The objective of the measurements is to determine the dependence of the dielectric constant of seawater on salinity and on temperature, more accurately than in the past. by taking advantage of modem instrumentation. The measurements of seawater permittivity have been performed as a function of salinity and temperature using a transmission resonant cavity technique. The measurements have been made in the salinity range of 10 to 38 psu and in the temperature range of IOU C to 35 C. These results will be useful in algorithm development for sensor systems such as SMOS and Aquarius. The measurement system consists of a brass microwave cavity that is resonant at 1.413 GHz. The seawater is introduced into the cavity through a capillary glass tube having an inner diameter of 0.1 mm. The diameter of the tube has been made very small so that the amount of seawater introduced in the cavity is small - thus maintaining the sensitivity of the measurements and allowing the use of perturbation theory predicting the seawater permittivity. The change in resonant frequency and the change in cavity Q can be used to determine the real and imaginary pare of the dielectric constant of seawater introduced into the slender tube. The microwave measurements are made by an HPS722D network analyzer. The cavity has been immersed in a uateriethylene-glycol bath which is connected to a Lauda circulator. The circulator keeps the brass cavity at a temperature constant to within 0.01 degrees. The system is automated using a Visual Basic program to control the analyzer and to collect the data. The results of the dielectric constant measurements of seawater will be presented. The measurement results will be

  17. Increased Accuracy in the Measurement of the Dielectric Constant of Seawater at 1.413 GHz

    Science.gov (United States)

    Zhou, Y.; Lang R.; Drego, C.; Utku, C.; LeVine, D.

    2012-01-01

    This paper describes the latest results for the measurements of the dielectric constant at 1.413 GHz by using a resonant cavity technique. The purpose of these measurements is to develop an accurate relationship for the dependence of the dielectric constant of sea water on temperature and salinity which is needed by the Aquarius inversion algorithm to retrieve salinity. Aquarius is the major instrument on the Aquarius/SAC-D observatory, a NASA/CONAE satellite mission launched in June of20ll with the primary mission of measuring global sea surface salinity to an accuracy of 0.2 psu. Aquarius measures salinity with a 1.413 GHz radiometer and uses a scatterometer to compensate for the effects of surface roughness. The core part of the seawater dielectric constant measurement system is a brass microwave cavity that is resonant at 1.413 GHz. The seawater is introduced into the cavity through a capillary glass tube having an inner diameter of 0.1 mm. The change of resonance frequency and the cavity Q value are used to determine the real and imaginary parts of the dielectric constant of seawater introduced into the thin tube. Measurements are automated with the help of software developed at the George Washington University. In this talk, new results from measurements made since September 2010 will be presented for salinities 30, 35 and 38 psu with a temperature range of O C to 350 C in intervals of 5 C. These measurements are more accurate than earlier measurements made in 2008 because of a new method for measuring the calibration constant using methanol. In addition, the variance of repeated seawater measurements has been reduced by letting the system stabilize overnight between temperature changes. The new results are compared to the Kline Swift and Meissner Wentz model functions. The importance of an accurate model function will be illustrated by using these model functions to invert the Aquarius brightness temperature to get the salinity values. The salinity values

  18. Full utilization of silt density index (SDI) measurements for seawater pre-treatment

    KAUST Repository

    Wei, Chunhai

    2012-07-01

    In order to clarify the fouling mechanism during silt density index (SDI) measurements of seawater in the seawater reverse osmosis (SWRO) desalination process, 11 runs were conducted under constant-pressure (207kPa) dead-end filtration mode according to the standard protocol for SDI measurement, in which two kinds of 0.45μm membranes of different material and seawater samples from the Mediterranean including raw seawater and seawater pre-treated by coagulation followed by sand filtration (CSF) and coagulation followed by microfiltration (CMF) technologies were tested. Fouling mechanisms based on the constant-pressure filtration equation were fully analyzed. For all runs, only t/(V/A)∼t showed very good linearity (correlation coefficient R 2>0.99) since the first moment of the filtration, indicating that standard blocking rather than cake filtration was the dominant fouling mechanism during the entire filtration process. The very low concentration of suspended solids rejected by MF of 0.45μm in seawater was the main reason why a cake layer was not formed. High turbidity removal during filtration indicated that organic colloids retained on and/or adsorbed in membrane pores governed the filtration process (i.e., standard blocking) due to the important contribution of organic substances to seawater turbidity in this study. Therefore the standard blocking coefficient k s, i.e., the slope of t/(V/A)∼t, could be used as a good fouling index for seawater because it showed good linearity with feed seawater turbidity. The correlation of SDI with k s and feed seawater quality indicated that SDI could be reliably used for seawater with low fouling potential (SDI 15min<5) like pre-treated seawater in this study. From both k s and SDI, the order of fouling potential was raw seawater>seawater pre-treated by CSF>seawater pre-treated by CMF, indicating the better performance of CMF than CSF. © 2012 Elsevier B.V.

  19. A measurement system for vertical seawater profiles close to the air-sea interface

    Science.gov (United States)

    Sims, Richard P.; Schuster, Ute; Watson, Andrew J.; Yang, Ming Xi; Hopkins, Frances E.; Stephens, John; Bell, Thomas G.

    2017-09-01

    This paper describes a near-surface ocean profiler, which has been designed to precisely measure vertical gradients in the top 10 m of the ocean. Variations in the depth of seawater collection are minimized when using the profiler compared to conventional CTD/rosette deployments. The profiler consists of a remotely operated winch mounted on a tethered yet free-floating buoy, which is used to raise and lower a small frame housing sensors and inlet tubing. Seawater at the inlet depth is pumped back to the ship for analysis. The profiler can be used to make continuous vertical profiles or to target a series of discrete depths. The profiler has been successfully deployed during wind speeds up to 10 m s-1 and significant wave heights up to 2 m. We demonstrate the potential of the profiler by presenting measured vertical profiles of the trace gases carbon dioxide and dimethylsulfide. Trace gas measurements use an efficient microporous membrane equilibrator to minimize the system response time. The example profiles show vertical gradients in the upper 5 m for temperature, carbon dioxide and dimethylsulfide of 0.15 °C, 4 µatm and 0.4 nM respectively.

  20. A measurement system for vertical seawater profiles close to the air–sea interface

    Directory of Open Access Journals (Sweden)

    R. P. Sims

    2017-09-01

    Full Text Available This paper describes a near-surface ocean profiler, which has been designed to precisely measure vertical gradients in the top 10 m of the ocean. Variations in the depth of seawater collection are minimized when using the profiler compared to conventional CTD/rosette deployments. The profiler consists of a remotely operated winch mounted on a tethered yet free-floating buoy, which is used to raise and lower a small frame housing sensors and inlet tubing. Seawater at the inlet depth is pumped back to the ship for analysis. The profiler can be used to make continuous vertical profiles or to target a series of discrete depths. The profiler has been successfully deployed during wind speeds up to 10 m s−1 and significant wave heights up to 2 m. We demonstrate the potential of the profiler by presenting measured vertical profiles of the trace gases carbon dioxide and dimethylsulfide. Trace gas measurements use an efficient microporous membrane equilibrator to minimize the system response time. The example profiles show vertical gradients in the upper 5 m for temperature, carbon dioxide and dimethylsulfide of 0.15 °C, 4 µatm and 0.4 nM respectively.

  1. A solvent extraction technique for the isotopic measurement of dissolved copper in seawater

    International Nuclear Information System (INIS)

    Thompson, Claire M.; Ellwood, Michael J.; Wille, Martin

    2013-01-01

    Graphical abstract: -- Highlights: •A new sample preparation method for seawater copper isotopic analysis (δ 65 Cu). •Solvent-extraction was used to pre-concentrate metals from seawater samples. •Anion-exchange was used to purify copper from the metal-rich extract. •δ 65 Cu was measured in the north Tasman Sea. •Seawater δ 65 Cu may be linked to marine biological activity. -- Abstract: Stable copper (Cu) isotope geochemistry provides a new perspective for investigating and understanding Cu speciation and biogeochemical Cu cycling in seawater. In this work, sample preparation for isotopic analysis employed solvent-extraction with amino pyrollidine dithiocarbamate/diethyl dithiocarbamate (APDC/DDC), coupled with a nitric acid back-extraction, to concentrate Cu from seawater. This was followed by Cu-purification using anion-exchange. This straightforward technique is high yielding and fractionation free for Cu and allows precise measurement of the seawater Cu isotopic composition using multi-collector inductively coupled plasma mass-spectrometry. A deep-sea profile measured in the oligotrophic north Tasman Sea shows fractionation in the Cu isotopic signature in the photic zone but is relatively homogenised at depth. A minima in the Cu isotopic profile correlates with the chlorophyll a maximum at the site. These results indicate that a range of processes are likely to fractionate stable Cu isotopes in seawater

  2. Diversity of bacterioplankton in the surface seawaters of Drake Passage near the Chinese Antarctic station.

    Science.gov (United States)

    Xing, Mengxin; Li, Zhao; Wang, Wei; Sun, Mi

    2015-07-01

    The determination of relative abundances and distribution of different bacterial groups is a critical step toward understanding the functions of various bacteria and its surrounding environment. Few studies focus on the taxonomic composition and functional diversity of microbial communities in Drake Passage. In this study, marine bacterioplankton communities from surface seawaters at five locations in Drake Passage were examined by 16S rRNA gene sequence analyses. The results indicated that psychrophilic bacteria were the most abundant group in Drake Passage, and mainly made up of Bacillus, Aeromonas, Psychrobacter, Pseudomonas and Halomonas. Diversity analysis showed that surface seawater communities had no significant correlation with latitudinal gradient. Additionally, a clear difference among five surface seawater communities was evident, with 1.8% OTUs (only two) belonged to Bacillus consistent across five locations and 71% OTUs (80) existed in only one location. However, the few cosmopolitans had the largest population sizes. Our results support the hypothesis that the dominant bacterial groups appear to be analogous between geographical sites, but significant differences may be detected among rare bacterial groups. The microbial diversity of surface seawaters would be liable to be affected by environmental factors. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Variability and trends in surface seawater pCO2 and CO2 flux in the Pacific Ocean

    Science.gov (United States)

    Sutton, A. J.; Wanninkhof, R.; Sabine, C. L.; Feely, R. A.; Cronin, M. F.; Weller, R. A.

    2017-06-01

    Variability and change in the ocean sink of anthropogenic carbon dioxide (CO2) have implications for future climate and ocean acidification. Measurements of surface seawater CO2 partial pressure (pCO2) and wind speed from moored platforms are used to calculate high-resolution CO2 flux time series. Here we use the moored CO2 fluxes to examine variability and its drivers over a range of time scales at four locations in the Pacific Ocean. There are significant surface seawater pCO2, salinity, and wind speed trends in the North Pacific subtropical gyre, especially during winter and spring, which reduce CO2 uptake over the 10 year record of this study. Starting in late 2013, elevated seawater pCO2 values driven by warm anomalies cause this region to be a net annual CO2 source for the first time in the observational record, demonstrating how climate forcing can influence the timing of an ocean region shift from CO2 sink to source.

  4. Temporal variations of 137Cs concentrations in the surface seawater and marine organisms collected from the Japanese coast during the 1980's

    International Nuclear Information System (INIS)

    Yamada, M.; Nagaya, Y.

    1998-01-01

    The surface seawater and marine organisms were collected on the Japanese coast and analyzed for their 137 Cs concentrations during the 1980's. The 137 Cs concentrations in surface seawater decreased almost exponentially with time and the 137 Cs removal rate constant was estimated to be 0.0445 y -1 . The 137 Cs concentrations in marine organisms also decreased almost exponentially with time. The environmental half-lives of 137 Cs in muscle and viscera of fish, crustacea, and seaweed were estimated from the measured decreases of 137 Cs concentrations. (author)

  5. Sampling problems and the determination of mercury in surface water, seawater, and air

    International Nuclear Information System (INIS)

    Das, H.A.; van der Sloot, H.A.

    1976-01-01

    Analysis of surface water for mercury comprises the determination of both ionic and organically bound mercury in solution and that of the total mercury content of the suspended matter. Eventually, metallic mercury has to be determined too. Requirements for the sampling procedure are given. A method for the routine determination of mercury in surface water and seawater was developed and applied to Dutch surface waters. The total sample volume is 2500 ml. About 500 ml is used for the determination of the content of suspended matter and the total amount of mercury in the water. The sample is filtered through a bed of previously purified active charcoal at a low flow-rate. The main portion ca. 2000 ml) passes a flow-through centrifuge to separate the solid fraction. One liter is used to separate ''inorganic'' mercury by reduction, volatilization in an airstream and adsorption on active charcoal. The other liter is led through a column of active charcoal to collect all mercury. The procedures were checked with 197 Hg radiotracer both as an ion and incorporated in organic compounds. The mercury is determined by thermal neutron activation, followed by volatilization in a tube furnace and adsorption on a fresh carbon bed. The limit of determination is approximately equal to 1 ng 1 -1 . The rate of desorption from and adsorption on suspended material has been measured as a function of a pH of the solution for Hg +2 and various other ions. It can be concluded that only the procedure mentioned above does not disturb the equilibrium. The separation of mercury from air is obtained by suction of 1 m 3 through a 0.22 μm filter and a charcoal bed. The determination is then performed as in the case of the water samples

  6. Standard practice for exposing and evaluating metals and alloys in surface seawater

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This practice covers conditions for the exposure of metals, alloys, and other materials in natural surface seawater such as those typically found in bays, harbors, channels, and so forth, as contrasted with deep ocean testing. This practice covers full immersion, tidal zone and related splash, and spray zone exposures. 1.2 This practice sets forth general procedures that should be followed in conducting seawater exposure tests so that meaningful comparisons may be made from one location to another. 1.3 This practice identifies recommended procedures for evaluating the effects of natural surface seawater on the materials exposed. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regula...

  7. Direct measurement of uranium in seawater by inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Qiao, Jixin; Xu, Yihong

    2018-01-01

    A simple method for direct measurement of uranium (238U) in seawater using triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS) was established. The method provides a good analytical performance with respect to detection limit, accuracy, precision and sample throughput. During...... samples taken from large volume of seawater stored in immovable containers for relatively long period (i.e., several months), the uranium concentration and salinity data showed slightly increasing trends with the increase of water depth in the container. Therefore, cautions need to be paid in sampling...

  8. Estimation of Surface Seawater Fugacity of Carbon Dioxide Using Satellite Data and Machine Learning

    Science.gov (United States)

    Jang, E.; Im, J.; Park, G.; Park, Y.

    2016-12-01

    The ocean controls the climate of Earth by absorbing and releasing CO2 through the carbon cycle. The amount of CO2 in the ocean has increased since the industrial revolution. High CO2 concentration in the ocean has a negative influence to marine organisms and reduces the ability of absorbing CO2 in the ocean. This study estimated surface seawater fugacity of CO2 (fCO2) in the East Sea of Korea using Geostationary Ocean Color Imager (GOCI) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data, and Hybrid Coordinate Ocean Model (HYCOM) reanalysis data. GOCI is the world first geostationary ocean color observation satellite sensor, and it provides 8 images with 8 bands hourly per day from 9 am to 4 pm at 500m resolution. Two machine learning approaches (i.e., random forest and support vector regression) were used to model fCO2 in this study. While most of the existing studies used multiple linear regression to estimate the pressure of CO2 in the ocean, machine learning may handle more complex relationship between surface seawater fCO2 and ocean parameters in a dynamic spatiotemporal environment. Five ocean related parameters, colored dissolved organic matter (CDOM), chlorophyll-a (chla), sea surface temperature (SST), sea surface salinity (SSS), and mixed layer depth (MLD), were used as input variables. This study examined two schemes, one with GOCI-derived products and the other with MODIS-derived ones. Results show that random forest performed better than support vector regression regardless of satellite data used. The accuracy of GOCI-based estimation was higher than MODIS-based one, possibly thanks to the better spatiotemporal resolution of GOCI data. MLD was identified the most contributing parameter in estimating surface seawater fCO2 among the five ocean related parameters, which might be related with an active deep convection in the East Sea. The surface seawater fCO2 in summer was higher in general with some spatial variation than the other

  9. Methodological Considerations and Comparisons of Measurement Results for Extracellular Proteolytic Enzyme Activities in Seawater

    Directory of Open Access Journals (Sweden)

    Yumiko Obayashi

    2017-10-01

    Full Text Available Microbial extracellular hydrolytic enzymes that degrade organic matter in aquatic ecosystems play key roles in the biogeochemical carbon cycle. To provide linkages between hydrolytic enzyme activities and genomic or metabolomic studies in aquatic environments, reliable measurements are required for many samples at one time. Extracellular proteases are one of the most important classes of enzymes in aquatic microbial ecosystems, and protease activities in seawater are commonly measured using fluorogenic model substrates. Here, we examined several concerns for measurements of extracellular protease activities (aminopeptidases, and trypsin-type, and chymotrypsin-type activities in seawater. Using a fluorometric microplate reader with low protein binding, 96-well microplates produced reliable enzymatic activity readings, while use of regular polystyrene microplates produced readings that showed significant underestimation, especially for trypsin-type proteases. From the results of kinetic experiments, this underestimation was thought to be attributable to the adsorption of both enzymes and substrates onto the microplate. We also examined solvent type and concentration in the working solution of oligopeptide-analog fluorogenic substrates using dimethyl sulfoxide (DMSO and 2-methoxyethanol (MTXE. The results showed that both 2% (final concentration of solvent in the mixture of seawater sample and substrate working solution DMSO and 2% MTXE provide similarly reliable data for most of the tested substrates, except for some substrates which did not dissolve completely in these assay conditions. Sample containers are also important to maintain the level of enzyme activity in natural seawater samples. In a small polypropylene containers (e.g., standard 50-mL centrifugal tube, protease activities in seawater sample rapidly decreased, and it caused underestimation of natural activities, especially for trypsin-type and chymotrypsin-type proteases. In

  10. A solvent extraction technique for the isotopic measurement of dissolved copper in seawater.

    Science.gov (United States)

    Thompson, Claire M; Ellwood, Michael J; Wille, Martin

    2013-05-02

    Stable copper (Cu) isotope geochemistry provides a new perspective for investigating and understanding Cu speciation and biogeochemical Cu cycling in seawater. In this work, sample preparation for isotopic analysis employed solvent-extraction with amino pyrollidine dithiocarbamate/diethyl dithiocarbamate (APDC/DDC), coupled with a nitric acid back-extraction, to concentrate Cu from seawater. This was followed by Cu-purification using anion-exchange. This straightforward technique is high yielding and fractionation free for Cu and allows precise measurement of the seawater Cu isotopic composition using multi-collector inductively coupled plasma mass-spectrometry. A deep-sea profile measured in the oligotrophic north Tasman Sea shows fractionation in the Cu isotopic signature in the photic zone but is relatively homogenised at depth. A minima in the Cu isotopic profile correlates with the chlorophyll a maximum at the site. These results indicate that a range of processes are likely to fractionate stable Cu isotopes in seawater. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  11. In situ spectrophotometric measurement of dissolved inorganic carbon in seawater

    Science.gov (United States)

    Liua, Xuewu; Byrne, Robert H.; Adornato, Lori; Yates, Kimberly K.; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

    2013-01-01

    Autonomous in situ sensors are needed to document the effects of today’s rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator’s molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg–1 and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

  12. Predicting and measurement of pH of seawater reverse osmosis concentrates

    KAUST Repository

    Waly, Tarek

    2011-10-01

    The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse osmosis pilot plant were compared with pH calculations based on the CO2-HCO3 --CO3 2- system equilibrium equations. Results were compared with two commercial software programs from membrane suppliers and also the software package Phreeqc. Results suggest that the real concentrate pH is lower than that of the feed and that none of the used programs was able to predict correctly real pH values. In addition, the effect of incorporating the acidity constant calculated for NaCl medium or seawater medium showed a great influence on the concentrate pH determination. The HCO3 - and CO3 2- equilibrium equation using acidity constants developed for seawater medium was the only method able to predict correctly the concentrate pH. The outcome of this study indicated that the saturation level of the concentrate was lower than previously anticipated. This was confirmed by shutting down the acid and the antiscalants dosing without any signs of scaling over a period of 12 months. © 2011 Elsevier B.V.

  13. High-precision measurements of seawater Pb isotope compositions by double spike thermal ionization mass spectrometry.

    Science.gov (United States)

    Paul, Maxence; Bridgestock, Luke; Rehkämper, Mark; van DeFlierdt, Tina; Weiss, Dominik

    2015-03-10

    A new method for the determination of seawater Pb isotope compositions and concentrations was developed, which combines and optimizes previously published protocols for the separation and isotopic analysis of this element. For isotopic analysis, the procedure involves initial separation of Pb from 1 to 2L of seawater by co-precipitation with Mg hydroxide and further purification by a two stage anion exchange procedure. The Pb isotope measurements are subsequently carried out by thermal ionization mass spectrometry using a (207)Pb-(204)Pb double spike for correction of instrumental mass fractionation. These methods are associated with a total procedural Pb blank of 28±21 pg (1sd) and typical Pb recoveries of 40-60%. The Pb concentrations are determined by isotope dilution (ID) on 50 mL of seawater, using a simplified version of above methods. Analyses of multiple aliquots of six seawater samples yield a reproducibility of about ±1 to ±10% (1sd) for Pb concentrations of between 7 and 50 pmol/kg, where precision was primarily limited by the uncertainty of the blank correction (12±4 pg; 1sd). For the Pb isotope analyses, typical reproducibilities (±2sd) of 700-1500 ppm and 1000-2000 ppm were achieved for (207)Pb/(206)Pb, (208)Pb/(206)Pb and (206)Pb/(204)Pb, (207)Pb/(204)Pb, (208)Pb/(204)Pb, respectively. These results are superior to literature data that were obtained using plasma source mass spectrometry and they are at least a factor of five more precise for ratios involving the minor (204)Pb isotope. Both Pb concentration and isotope data, furthermore, show good agreement with published results for two seawater intercomparison samples of the GEOTRACES program. Finally, the new methods were applied to a seawater depth profile from the eastern South Atlantic. Both Pb contents and isotope compositions display a smooth evolution with depth, and no obvious outliers. Compared to previous Pb isotope data for seawater, the (206)Pb/(204)Pb ratios are well correlated

  14. Spectrophotometric measurement of calcium carbonate saturation states in seawater.

    Science.gov (United States)

    Easley, Regina A; Patsavas, Mark C; Byrne, Robert H; Liu, Xuewu; Feely, Richard A; Mathis, Jeremy T

    2013-02-05

    Measurements of ocean pH and carbonate ion concentrations in the North Pacific and Arctic Oceans were used to determine calcium carbonate saturation states (Ω(CaCO(3))) from spectrophotometric methods alone. Total carbonate ion concentrations, [CO(3)(2-)](T), were for the first time at sea directly measured using Pb(II) UV absorbance spectra. The basis of the method is given by the following: [formula see text] where (CO(3))β(1) is the PbCO(3)(0) formation constant, e(i) are molar absorptivity ratios, and R = (250)A/(234)A (ratio of absorbances measured at 250 and 234 nm). On the basis of shipboard and laboratory Pb(II) data and complementary carbon-system measurements, the experimental parameters were determined to be (25 °C) the following: [formula see text]. The resulting mean difference between the shipboard spectrophotometric and conventional determinations of [CO(3)(2-)](T) was ±2.03 μmol kg(-1). The shipboard analytical precision of the Pb(II) method was ∼1.71 μmol kg(-1) (2.28%). Spectrophotometric [CO(3)(2-)](T) and pH(T) were then combined to calculate Ω(CaCO(3)). For the case of aragonite, 95% of the spectrophotometric aragonite saturation states (Ω(Aspec)) were within ±0.06 of the conventionally calculated values (Ω(Acalc)) when 0.5 ≤ Ω(A) ≤ 2.0. When Ω(A) > 2.0, 95% of the Ω(Aspec) values were within ±0.18 of Ω(Acalc). Our shipboard experience indicates that spectrophotometric determinations of [CO(3)(2-)](T) and Ω(CaCO(3)) are straightforward, fast, and precise. The method yields high-quality measurements of two important, rapidly changing aspects of ocean chemistry and offers capabilities suitable for long-term automated in situ monitoring.

  15. A miniature all-solid-state calcium electrode applied to in situ seawater measurement

    International Nuclear Information System (INIS)

    Xu, Hui; Wang, You; Luo, Zhiyuan; Pan, Yiwen

    2013-01-01

    An all-solid-state miniature calcium ion selective electrode (ISE) based on poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT(PSS)) for continuous in situ measurement in seawater was studied. The electrode substrate was a platinum (Pt) wire of 0.5 mm diameter and PEDOT(PSS) was electropolymerized on one end of the Pt wire to act as the solid contact of this calcium ISE. The PEDOT(PSS) layer was covered with a calcium-selective poly(vinyl chloride) membrane, which contained ETH129 as calcium ionophore, potassium tetrakis-(p-chlorophenyl)borate as lipophilic anion and bis(2-ethylhexyl) sebacate as the plasticizer. Experiments using electrochemical impedance spectroscopy and reversed chronopotentiometry illustrated that electropolymerized PEDOT(PSS) decreased the resistance and improved the stability of the electrode. The sensors can work stably in the calcium ion concentration range of 10 −6 –10 −1 mol L −1  with the slope of 27.7 mV/decade. Also Na + , K +  and Mg 2+  can hardly interfere with the performance of the electrode. This electrode was applied to measure the calcium ion concentration of seawater samples. The experimental data showed that the electrode can resist the corrosion of seawater and its reproducibility was good (SD < 0.1 mM kg −1 ). The lifetime of such an electrode was at least six months. Because of the wire-shape and the small size of such a liquid junction free calcium electrode, it is pressure-resistant and easy to package and seal, therefore it is suitable for use in underwater equipment for in situ seawater measurement. (paper)

  16. Surface cleanliness measurement procedure

    Science.gov (United States)

    Schroder, Mark Stewart; Woodmansee, Donald Ernest; Beadie, Douglas Frank

    2002-01-01

    A procedure and tools for quantifying surface cleanliness are described. Cleanliness of a target surface is quantified by wiping a prescribed area of the surface with a flexible, bright white cloth swatch, preferably mounted on a special tool. The cloth picks up a substantial amount of any particulate surface contamination. The amount of contamination is determined by measuring the reflectivity loss of the cloth before and after wiping on the contaminated system and comparing that loss to a previous calibration with similar contamination. In the alternative, a visual comparison of the contaminated cloth to a contamination key provides an indication of the surface cleanliness.

  17. Phylogenetic diversity of culturable bacteria in surface seawater from the Drake Passage, Antarctica

    Science.gov (United States)

    Li, Zhao; Xing, Mengxin; Wang, Wei; Wang, Dan; Zhu, Jiancheng; Sun, Mi

    2016-09-01

    The Drake Passage is located between the Antarctic Peninsula and Tierra del Fuego in the south of South America. Surface seawater samples were collected at seven sites in the Drake Passage during the austral summer of 2012. The 16S rRNA sequences were analyzed from 187 isolated bacterial strains. Three phyla, 29 genera and 56 species were identified. The three phyla were Actinobacteria, Firmicutes and Proteobacteria; the Proteobacteria included α-Proteobacteria, β-Proteobacteria and γ-Proteobacteria. γ-Proteobacteria, Actinobacteria and Firmicutes were the dominant class or phyla in terms of quantity and species. Gram-positive bacteria (Actinobacteria and Firmicutes) accounted for 57.8% of all types identified. There were nine dominant genera, including Curtobacterium, Staphylococcus, and Halomonas, and 14 dominant species including Curtobacterium flaccumfaciens, Curtobacterium pusillum, and Staphylococcus sciuri. Of the strains identified, 87.2% were catalase positive or weakly positive.

  18. Long-term stability of PEG-based antifouling surfaces in seawater

    DEFF Research Database (Denmark)

    Noguer, Albert Camós; Olsen, Stefan Møller; Hvilsted, Søren

    2016-01-01

    , in both accelerated laboratory tests and real seawater conditions. This article shows how PEG-based copolymers, which have been exposed in fouling-release coatings to real-life seawater conditions, are isolated and compared to those exposed to accelerated laboratory testing with successful results...

  19. Abundance and Distribution Characteristics of Microplastics in Surface Seawaters of the Incheon/Kyeonggi Coastal Region.

    Science.gov (United States)

    Chae, Doo-Hyeon; Kim, In-Sung; Kim, Seung-Kyu; Song, Young Kyoung; Shim, Won Joon

    2015-10-01

    Microplastics in marine environments are of emerging concern due to their widespread distribution, their ingestion by various marine organisms, and their roles as a source and transfer vector of toxic chemicals. However, our understanding of their abundance and distribution characteristics in surface seawater (SSW) remains limited. We investigated microplastics in the surface microlayer (SML) and the SSW at 12 stations near-shore and offshore of the Korean west coast, Incheon/Kyeonggi region. Variation between stations, sampling media, and sampling methods were compared based on abundances, size distribution, and composition profiles of microsized synthetic polymer particles. The abundance of microplastics was greater in the SML (152,688 ± 92,384 particles/m(3)) than in SSW and showed a significant difference based on the sampling method for SSWs collected using a hand net (1602 ± 1274 particles/m(3)) and a zooplankton trawl net (0.19 ± 0.14 particles/m(3)). Ship paint particles (mostly alkyd resin polymer) accounted for the majority of microplastics detected in both SML and SSWs, and increased levels were observed around the voyage routes of large vessels. This indicates that polymers with marine-based origins become an important contributor to microplastics in coastal SSWs of this coastal region.

  20. Impact of surface ocean conditions and aerosol provenance on the dissolution of aerosol manganese, cobalt, nickel and lead in seawater

    OpenAIRE

    Fishwick, MP; Ussher, SJ; Sedwick, PN; Lohan, MC; Worsfold, PJ; Buck, KN; Church, TM

    2018-01-01

    © 2017. Atmospheric deposition is an important pathway by which bioactive trace metals are delivered to the surface ocean. The proportions of total aerosol trace metals that dissolve in seawater, and thus become available to biota, are not well constrained and are therefore a key uncertainty when estimating atmospheric fluxes of these elements to surface waters. The aim of this study was to elucidate the main physico-chemical controls on the dissolution of the bioactive trace metals manganese...

  1. Metrological challenges for measurements of key climatological observables. Part 3: seawater pH

    Science.gov (United States)

    Dickson, A. G.; Camões, M. F.; Spitzer, P.; Fisicaro, P.; Stoica, D.; Pawlowicz, R.; Feistel, R.

    2016-02-01

    Water dissolves many substances with which it comes into contact, leading to a variety of aqueous solutions ranging from simple and dilute to complex and highly concentrated. Of the multiple chemical species present in these solutions, the hydrogen ion, H+, stands out in importance due to its relevance to a variety of chemical reactions and equilibria that take place in aquatic systems. This importance, and the fact that its presence can be assessed by reliable and inexpensive procedures, are the reasons why pH is perhaps the most measured chemical parameter. In this paper, while examining climatologically relevant ocean pH, we note fundamental problems in the definition of this key observable, and its lack of secure foundation on the International System of Units, the SI. The metrological history of seawater pH is reviewed, difficulties arising from its current definition and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent TEOS-10 seawater standard. It is concluded that the International Bureau of Weights and Measures (BIPM), in cooperation with the International Association for the Properties of Water and Steam (IAPWS), along with other international organisations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems.

  2. Isotopic measurements in research on seawater ingression in the carbonate aquifer of the Salentine Peninsula, Southern Italy

    International Nuclear Information System (INIS)

    Cotecchia, V.; Tazioli, G.S.; Magri, G.

    1974-01-01

    Cretaceous calcareous and dolomitic rocks, bedded, jointed and karstified, and hence generally very permeable, form the basement of the Salentine Peninsula. These rocks constitute a huge aquifer with fresh and brackish groundwaters that float on groundwaters of marine origin. Sea level constitutes the base level of the ground waters. A basic outline is first given of the hydrogeology and the paleohydrogeology, so as to provide the necessary background information on the seawater intrusion phenomenon and to permit comparison of the results of the isotope data with those obtained by the classical methods of hydrogeological investigation. This is followed by presentation of the results of the isotopic measurements on 18 O, D, 13 C and 14 C. The δ 13 C contents indicate, in good agreement with the carbon dioxide and bicarbonate concentrations, that seawater ingression leads to the migration of carbon dioxide from the fresh and brackish waters towards the subjacent intrusive waters of marine origin. Along those stretches of coast where the seawaters are in direct communication with the groundwaters, all the isotope data point to very active renewal of groundwaters of marine origin by seawater. In the central parts of the peninsula and along those stretches of coast where direct communication between seawaters and groundwaters is impeded by impervious clays, the 14 C contents indicate that the seawater intrusion and consequently the migration of carbon dioxide are either very slow and continuous in time or that they occurred relatively rapidly in the past. Taking into consideration the paleohydrogeology of the peninsula, and the fact that the δ 18 O and δD values are higher than those of the present seawaters, leads to the belief that seawater intrusion may well have occurred during major variations in the sea level in the past, when climatic conditions were different from those now prevailing. (author)

  3. The Zn abundance and isotopic composition of diatom frustules, a proxy for Zn availability in ocean surface seawater

    Science.gov (United States)

    Andersen, Morten B.; Vance, Derek; Archer, Corey; Anderson, Robert F.; Ellwood, Michael J.; Allen, Claire S.

    2011-01-01

    We have developed cleaning methods for extracting diatomopal from bulk marine sediment samples, for measurement of both zinc (Zn) abundance and isotope composition. This cleaning technique was then applied to a set of Holocene core-top samples from the Southern Ocean. The measured δ66Zn (reported relative to the JMCLyon standard) and Zn/Si ratios from the Southern Ocean diatomopal samples range from 0.7 to 1.5‰, and from 14 to 0.9 μmol/mol, respectively. The Zn abundance and isotope composition data show a clear correlation with opal burial rates and other oceanographic parameters. In common with previous work, we interpret the systematic changes in the Zn/Si ratio to be linked to the variability in the concentrations of bioavailable Zn in the ambient surface seawater where the diatom opal is formed. This variability is likely to be primarily controlled by the degree to which Zn is taken up into phytoplankton biomass. The observed systematic pattern in the δ66Zn compositions of the diatomopal core-top samples is, similarly, likely to reflect changes in the δ66Zn composition of the ambient Zn in the surface waters above the core-top sites, which is progressively driven towards isotopically heavier values by preferential incorporation of the lighter isotopes into phytoplankton organic material. Thus, the systematic relationship between Zn isotopes and abundance observed in the core-top diatomopal samples suggests a potential tool for investigating the biogeochemical cycling of Zn in the past surface ocean for down-core diatomopal material. In this respect, it may be possible to test hypotheses that attribute variations in atmospheric CO2 on glacial-interglacial timescales to the degree to which trace metals limited primary productivity in HNLC zones.

  4. Metaproteomic characterization of high molecular weight dissolved organic matter in surface seawaters in the South China Sea

    Science.gov (United States)

    Dong, Hong-Po; Wang, Da-Zhi; Xie, Zhang-Xian; Dai, Min-Han; Hong, Hua-Sheng

    2013-05-01

    Dissolved organic matter (DOM) is an important reservoir of carbon and energy in the marine environment and plays a key role in regulating the global carbon cycle. This study characterized proteins of high-molecular-weight DOM (size between 5 kDa and classification and function dominated the dissolved protein pool (43-53%) while the remaining proteins presented close similarity in biological origin among the four sampling sites. Rhodospirillaceae, Prochlorococcus, SAR11 clade and viruses were the major contributors to dissolved proteins in the HMW-DOM from surface seawaters while very few proteins were from the eukaryotic phytoplankton and no archaeal proteins were detected. Transporters with substrate specificities for nitrogen- and carbon-containing compounds (1.5% of the total spectra for each) were highly detected while no phosphate transporters were found, suggesting that carbon and nitrogen might be more limiting than phosphorus in the surface seawater. Viral proteins were assigned into three families: Myoviridae, Podoviridae and Siphoviridae, and the Myoviridae proteins were the most abundant. Among them, structure proteins were the most abundant viral proteins. This study indicated that the dissolved proteins of HMW-DOM presented compositional and biologically original homogeneity in the surface seawaters of the South China Sea, and bacteria and viruses dominated the dissolved protein pool.

  5. Spectrophotometric high-precision seawater pH determination for use in underway measuring systems

    Directory of Open Access Journals (Sweden)

    S. Aßmann

    2011-10-01

    Full Text Available Autonomous sensors are required for a comprehensive documentation of the changes in the marine carbon system and thus to differentiate between its natural variability and anthropogenic impacts. Spectrophotometric determination of pH – a key variable of the seawater carbon system – is particularly suited to achieve precise and drift-free measurements. However, available spectrophotometric instruments are not suitable for integration into automated measurement systems (e.g. FerryBox since they do not meet the major requirements of reliability, stability, robustness and moderate cost. Here we report on the development and testing of a~new indicator-based pH sensor that meets all of these requirements. This sensor can withstand the rough conditions during long-term deployments on ships of opportunity and is applicable to the open ocean as well as to coastal waters with a complex matrix and highly variable conditions. The sensor uses a high resolution CCD spectrometer as detector connected via optical fibers to a custom-made cuvette designed to reduce the impact of air bubbles. The sample temperature can be precisely adjusted (25 °C ± 0.006 °C using computer-controlled power supplies and Peltier elements thus avoiding the widely used water bath. The overall setup achieves a measurement frequency of 1 min−1 with a precision of ±0.0007 pH units, an average offset of +0.0005 pH units to a reference system, and an offset of +0.0081 pH units to a certified standard buffer. Application of this sensor allows monitoring of seawater pH in autonomous underway systems, providing a key variable for characterization and understanding of the marine carbon system.

  6. Influence of vertical temperature contrasts and diel cycles on near-surface seawater pCO2

    Science.gov (United States)

    Matthews, Robin; deYoung, Brad

    2016-04-01

    While the oceanic mixed layer is sometimes assumed to be of vertically-uniform temperature, it is well-known that considerable temperature gradients (>0.1C/m) can develop within its upper few meters, particularly in the tropics during daytime. Given that the partial pressure of CO2 in seawater (pCO2sw) is strongly temperature-dependent, ceteris paribus (all else being equal), we would expect to observe sizeable corresponding vertical pCO2sw gradients under such situations. If prevalent and persistent, such gradients could affect the accuracy of large-scale air-sea CO2 flux estimates since, while intended to be representative of the sea surface skin, the pCO2sw measurements used to compute these are typically from underway systems sampling at 2-4m depth. Vertical variability in pCO2sw could thus be an important but as yet, poorly quantified uncertainty in air-sea CO2 flux estimates. As a first step towards assessing this uncertainty, we derive a global gridded monthly climatology for the peak daily vertical temperature contrast between the upper (0-2m) and lower (2-10m) sea surface and compute the corresponding vertical pCO2sw differences these would cause, ceteris paribus. The latter are an estimate of the temperature-driven pCO2 contrast we would expect to find in a given month between the upper sea surface and the sampling depth of an underway system at the time of the peak temperature contrast in the daily cycle. In addition, we construct a monthly climatology for the amplitude of diel variation in upper sea temperature and compute the corresponding diel pCO2sw amplitudes these would generate, ceteris paribus. While these analyses reveal the locations and months for which vertical temperature contrasts and diel cycles are likely to exert a strong influence on pCO2sw, temperature is only one factor influencing this carbonate chemistry parameter. In situ measurements are required to reveal the actual dynamics of pCO2sw under the influence of all competing factors

  7. Development of a copper-substituted, Prussian blue-impregnated, nonwoven cartridge filter to rapidly measure radiocesium concentration in seawater

    International Nuclear Information System (INIS)

    Yasutaka, Tetsuo; Takahashi, Akira; Kawamoto, Tohru; Miyazu, Susumu; Kondo, Yoshihiko; Tsuji, Hideki; Arita, Koichi; Hayashi, Seiji; Aoyama, Michio

    2016-01-01

    This paper presents a cartridge filter incorporating a nonwoven fabric impregnated with Prussian blue copper analog (Cu-CF) to effectively concentrate and quantify radiocesium dissolved in seawater. The recovery ratio of the Cu-CF was >95% in laboratory experiments at a flow rate of 0.5 L min -1 through the filter and >93% in field experiments. Test measurements of 137 Cs concentrations in seawater using Cu-CF agreed with the results obtained by using a conventional coprecipitation method that employed ammonium phosphomolybdate (within the counting error of the detector). The proposed method can shorten the preconcentration and pretreatment times for radiocesium, to just 40 min in 20 L of seawater, which is much faster than the ∼1 week required by traditional ammonium phosphomolybdate methods. (author)

  8. Flavobacterium nitratireducens sp. nov., an amylolytic bacterium of the family Flavobacteriaceae isolated from coastal surface seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Nupur; Bhumika, V.; Srinivas, T.N.R.; AnilKumar, P.

    . Nogi, Y., Soda, K. & Oikawa, T. (2005). Flavobacterium frigidimaris sp. nov., isolated from Antarctic seawater. Syst Appl Microbiol 28, 310-315. Ryu, S. H., Park, J. H., Moon, J. C., Sung, Y., Lee, S. S. & Jeon, C. O. (2008). Flavobacterium...

  9. Chlorine-36 in seawater

    International Nuclear Information System (INIS)

    Argento, David C.; Stone, John O.; Keith Fifield, L.; Tims, Stephen G.

    2010-01-01

    Natural cosmogenic 36 Cl found in seawater originates from spallation of atmospheric 40 Ar, capture of secondary cosmic-ray neutrons by dissolved 35 Cl, and river runoff which contains 36 Cl produced in situ over the surface of the continents. The long residence time of chloride in the ocean and long half-life of 36 Cl compared to the oceanic mixing time should result in a homogenous 36 Cl/Cl ratio throughout the ocean. Production by neutron capture in the course of nuclear weapons testing should be insignificant averaged over the oceans as a whole, but may have led to regions of elevated 36 Cl concentration. Previous attempts to measure the 36 Cl/Cl ratio of seawater have been hindered by interferences, contamination, or insufficient analytic sensitivity. Here we report preliminary measurements on seawater samples, which demonstrate that the 36 Cl/Cl ratio is 0.5 ± 0.3 x 10 -15 , in reasonable agreement with calculated contributions from the sources listed above.

  10. Physiological and genomic features of a novel violacein-producing bacterium isolated from surface seawater.

    Directory of Open Access Journals (Sweden)

    Yue-Hong Wu

    Full Text Available Strains JW1T and JW3, isolated from surface seawater of the Arabian Sea, were subjected to polyphasic taxonomic analysis. Cells of both strains were Gram-stain-negative, aerobic, and rod-shaped. They formed violet pigment and produced violacein. On the basis of 16S rRNA gene sequence analysis, strains JW1T and JW3 showed high 16S rRNA gene sequence similarity with Pseudoalteromonas byunsanensis JCM12483T (98.2%, P. shioyasakiensis SE3T (97.8%, P. arabiensis JCM 17292T (97.3%, and P. gelatinilytica NH153T (97.1%. The 16S rRNA gene sequence similarity between JW1T and JW3 was 100%. Phylogenetic analyses revealed that both strains fell within the cluster of the genus Pseudoalteromonas and represented an independent lineage. The average nucleotide identity and in silico DNA-DNA hybridization values between JW1T and type strains of the closely related Pseudoalteromonas species were 70.9-83.3% and 20.0-26.4%, respectively. The sole respiratory quinone in both strains is ubiquinone 8 (Q-8. The principal fatty acids are summed feature 3 (C16:1ω7c and/or iso-C15:0 2OH, C18:1ω7c, and C16:0. The major polar lipids are phosphatidylethanolamine, phosphatidylglycerol, one unidentified glycolipid, one unidentified aminolipid, and one unidentified phospholipid. The DNA G+C content was 43.3 mol%. Differential phylogenetic distinctiveness, chemotaxonomic differences, and phenotypic properties indicated that strains JW1T and JW3 could be differentiated from the Pseudoalteromonas species with validly published names. Therefore, it is proposed that strains JW1T and JW3 represent a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas amylolytica sp. nov. (type strain, JW1T = CGMCC 1.15681T = KCTC 52406T = MCCC 1K02162T is proposed.

  11. Corrosion behavior of super-hydrophobic surface on copper in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tao; Chen Shougang; Cheng Sha; Tian Jintao; Chang Xueting [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China); Yin Yansheng [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China)], E-mail: yys2003@ouc.edu.cn

    2007-11-01

    A novel super-hydrophobic film was prepared by myristic acid (n-tetradecanoic) chemically adsorbed onto the copper wafer. The film formation and its structure were characterized by means of water contact angle measurement, Fourier transformation infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The static contact angle for water on the surface of this organic film was measured to be as high as 158{sup o}. The formation of a composite interface composed of the flower-like surface nanostructures, water droplet and air trapped in the crevices was suggested to be responsible for the superior water-repellent property. The corrosion behavior of the super-hydrophobic surface was investigated with potentiodynamic polarization measurements and electrochemical impedance spectroscopy. Due to the 'air valleys' and 'capillarity' effects, the corrosion resistance of the material was improved remarkably.

  12. Corrosion behavior of super-hydrophobic surface on copper in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tao; Chen, Shougang; Cheng, Sha; Tian, Jintao; Chang, Xueting; Yin, Yansheng [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China)

    2007-11-01

    A novel super-hydrophobic film was prepared by myristic acid (n-tetradecanoic) chemically adsorbed onto the copper wafer. The film formation and its structure were characterized by means of water contact angle measurement, Fourier transformation infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The static contact angle for water on the surface of this organic film was measured to be as high as 158 . The formation of a composite interface composed of the flower-like surface nanostructures, water droplet and air trapped in the crevices was suggested to be responsible for the superior water-repellent property. The corrosion behavior of the super-hydrophobic surface was investigated with potentiodynamic polarization measurements and electrochemical impedance spectroscopy. Due to the 'air valleys' and 'capillarity' effects, the corrosion resistance of the material was improved remarkably. (author)

  13. Technical Note: Precise quantitative measurements of total dissolved inorganic carbon from small amounts of seawater using a gas chromatographic system

    Directory of Open Access Journals (Sweden)

    T. Hansen

    2013-10-01

    Full Text Available Total dissolved inorganic carbon (CT is one of the most frequently measured parameters used to calculate the partial pressure of carbon dioxide in seawater. Its determination has become increasingly important because of the rising interest in the biological effects of ocean acidification. Coulometric and infrared detection methods are currently favored in order to precisely quantify CT. These methods however are not sufficiently validated for CT measurements of biological experiments manipulating seawater carbonate chemistry with an extended CT measurement range (~1250–2400 μmol kg–1 compared to natural open ocean seawater (~1950–2200 μmol kg−1. The requirement of total sample amounts between 0.1–1 L seawater in the coulometric- and infrared detection methods potentially exclude their use for experiments working with much smaller volumes. Additionally, precise CT analytics become difficult with high amounts of biomass (e.g., phytoplankton cultures or even impossible in the presence of planktonic calcifiers without sample pre-filtration. Filtration however, can alter CT concentration through gas exchange induced by high pressure. Addressing these problems, we present precise quantification of CT using a small, basic and inexpensive gas chromatograph as a CT analyzer. Our technique is able to provide a repeatability of ±3.1 μmol kg−1, given by the pooled standard deviation over a CT range typically applied in acidification experiments. 200 μL of sample is required to perform the actual CT measurement. The total sample amount needed is 12 mL. Moreover, we show that sample filtration is applicable with only minor alteration of the CT. The method is simple, reliable and with low cumulative material costs. Hence, it is potentially attractive for all researchers experimentally manipulating the seawater carbonate system.

  14. Surface modification of seawater desalination reverse osmosis membranes: Characterization studies & performance evaluation

    KAUST Repository

    Matin, Asif

    2014-06-01

    In this work we report surface modification of commercial reverse osmosis membranes by depositing ultrathin copolymer coatings, which could potentially enhance the biofouling resistance of RO membranes. Hydrophilic monomer hydroxyethyl methacrylate (HEMA) and a hydrophobic monomer, perfluorodecyl acrylate (PFDA) were copolymerized directly on the active layer of commercial aromatic polyamide reverse osmosis (RO) membranes using an initiated Chemical Vapor Deposition (iCVD) technique. Attenuated total reflective Fourier transform infrared spectra (ATR-FTIR) verified the successful modification of the membrane surfaces as a new FTIR adsorption band around 1730cm-1 corresponding to carbonyl groups in the copolymer film appeared after the deposition. X-ray Photoelectron spectroscopy (XPS) analysis also confirmed the presence of the copolymer film on the membrane surface by showing strong fluorine peaks emanating from the fluorinated alkyl side chains of the PFA molecules. Contact angle measurements with deionized water showed the modified membrane surfaces to be initially very hydrophobic but quickly assumed a hydrophilic character within few minutes. Atomic Force Microscopy (AFM) revealed that the deposited films were smooth and conformal as the surface topology of the underlying membrane surface remained virtually unchanged after the deposition. FESEM images of the top surface also showed that the typical ridge-and-valley structure associated with polyamide remained intact after the deposition. Short-term permeation tests using DI water and 2000ppm NaCl water showed that the deposited copolymer coatings had negligible effect on permeate water flux and salt rejection. © 2013 Elsevier B.V.

  15. Isolation and Characterization of Surface and Subsurface Bacteria in Seawater of Mantanani Island, Kota Belud, Sabah by Direct and Enrichment Techniques

    Science.gov (United States)

    Benard, L. D.; Tuah, P. M.; Suadin, E. G.; Jamian, N.

    2015-04-01

    The distribution of hydrocarbon-utilizing bacterial may vary between surface and subsurface of the seawater. One of the identified contributors is the Total Petroleum Hydrocarbon. The isolation and characterization of bacteria using Direct and Enrichment techniques helps in identifying dominant bacterial populations in seawater of Mantanani Island, Kota Belud, Sabah, potential of further investigation as hydrocarbon degrader. Crude oil (5% v/v) was added as the carbon source for bacteria in Enrichment technique. For surface seawater, the highest population of bacteria identified for both Direct and Enrichment technique were 2.60 × 107 CFU/mL and 3.84 × 106 CFU/mL respectively. Meanwhile, for subsurface seawater, the highest population of bacteria identified for both Direct and Enrichment technique were 5.21 × 106 CFU/mL and 8.99 × 107 CFU/mL respectively. Dominant species in surface seawater were characterized as Marinobacter hydrocarbonoclasticus-RMSF-C1 and RMSF-C2 and Alcanivorax borkumensis-RMSF-C3, RMSF-C4 and RMSF-C5. As for subsurface seawater, dominant species were characterized as Pseudomonas luteola-SSBR-W1, Burkholderia cepacia-SSBR-C1, Rhizobium radiobacter- SSBR-C3 and Leuconostoc-cremois -SSBR-C4.

  16. Isolation and Characterization of Surface and Subsurface Bacteria in Seawater of Mantanani Island, Kota Belud, Sabah by Direct and Enrichment Techniques

    International Nuclear Information System (INIS)

    Benard, L D; Tuah, P M; Suadin, E G; Jamian, N

    2015-01-01

    The distribution of hydrocarbon-utilizing bacterial may vary between surface and subsurface of the seawater. One of the identified contributors is the Total Petroleum Hydrocarbon. The isolation and characterization of bacteria using Direct and Enrichment techniques helps in identifying dominant bacterial populations in seawater of Mantanani Island, Kota Belud, Sabah, potential of further investigation as hydrocarbon degrader. Crude oil (5% v/v) was added as the carbon source for bacteria in Enrichment technique. For surface seawater, the highest population of bacteria identified for both Direct and Enrichment technique were 2.60 × 10 7 CFU/mL and 3.84 × 10 6 CFU/mL respectively. Meanwhile, for subsurface seawater, the highest population of bacteria identified for both Direct and Enrichment technique were 5.21 × 10 6 CFU/mL and 8.99 × 10 7 CFU/mL respectively. Dominant species in surface seawater were characterized as Marinobacter hydrocarbonoclasticus-RMSF-C1 and RMSF-C2 and Alcanivorax borkumensis-RMSF-C3, RMSF-C4 and RMSF-C5. As for subsurface seawater, dominant species were characterized as Pseudomonas luteola-SSBR-W1, Burkholderia cepacia-SSBR-C1, Rhizobium radiobacter- SSBR-C3 and Leuconostoc-cremois -SSBR-C4. (paper)

  17. Accelerator Mass Spectrometry Measurements of Plutonium in Sediment and Seawater from the Marshall Islands

    Energy Technology Data Exchange (ETDEWEB)

    Leisvik, Mathias [Lund Univ. (Sweden)

    2001-08-01

    were of main interest and not the technique. The second part was to take advantage of AMS's very high sensitivity by measure the Pu-concentrations in small volumes (0.04-1 L) of seawater. The technique for using AMS at Pu-measurements in seawater is relatively new and the main task for me was to find out a method that could work in practice. The area where the sediment samples and the water samples were collected are high above background levels for many radionuclides, including Pu, because of the detonation of the nuclear bomb code-named Castle Bravo, in 1954.

  18. Perfluoroalkyl acids in surface seawater from the North Pacific to the Arctic Ocean: Contamination, distribution and transportation.

    Science.gov (United States)

    Li, Lei; Zheng, Hongyuan; Wang, Tieyu; Cai, Minghong; Wang, Pei

    2018-03-16

    The bioaccumulative, persistent and toxic properties of long-chain perfluoroalkyl acids (PFAAs) resulted in strict regulations on PFAAs, especially in developed countries. Consequently, the industry manufacturing of PFAAs shifts from long-chain to short-chain. In order to better understand the pollution situation of PFAAs in marine environment under this new circumstance, the occurrence of 17 linear PFAAs was investigated in 30 surface seawater samples from the North Pacific to Arctic Ocean (123°E to 24°W, 32 to 82°N) during the sixth Chinese Arctic Expedition in 2014. Total concentrations of PFAAs (∑PFAAs) were between 346.9 pg per liter (pg/L) to 3045.3 pg/L. The average concentrations of ∑PFAAs decreased in the order of East China Sea (2791.4 pg/L, n = 2), Sea of Japan (East Sea) (832.8 pg/L, n = 6), Arctic Ocean (516.9 pg/L, n = 7), Chukchi Sea (505.2 pg/L, n = 4), Bering Sea (501.2 pg/L, n = 8) and Sea of Okhotsk (417.7 pg/L, n = 3). C4 to C9 perfluoroalkyl carboxylic acids (PFCAs) were detected in more than 80% of the surface water samples. Perfluorobutanoic acid (PFBA) was the most prevalent compound and perfluorooctanoic acid (PFOA) was the second abundant homolog. The concentration of individual PFAAs in the surface seawater of East China Sea was much higher than other sampling seas. As the spatial distribution of PFAAs in the marine environment was mainly influenced by the river inflow from the basin countries, which proved the large input from China. Furthermore, the marginal seas of China were found with the greatest burden of PFOA comparing the pollution level in surface seawater worldwide. PFBA concentration in the surrounding seas of China was also high, but distributed more evenly with an obvious increase in recent years. This large-scale monitoring survey will help the improvement and development of PFAAs regulations and management, where production shift should be taken into consideration. Copyright

  19. Characterization of pigment-leached antifouling coatings using BET surface area measurements and mercury porosimetry

    DEFF Research Database (Denmark)

    Kiil, Søren; Dam-Johansen, Kim

    2007-01-01

    In this work BET surface area measurements and mercury porosimetry are used to characterize leached layers formed when seawater-soluble pigments (Cu2O and ZnO) dissolve during accelerated leaching of simple antifouling coatings. Measurements on single-pigment coatings show that an increasing...

  20. Identification and characterization of 1,4-dioxane-degrading microbe separated from surface seawater by the seawater-charcoal perfusion apparatus.

    Science.gov (United States)

    Matsui, Ryotaro; Takagi, Kazuhiro; Sakakibara, Futa; Abe, Tomoko; Shiiba, Kiwamu

    2016-06-01

    To determine the concentration of soluble 1,4-dioxane during biodegradation, a new method using of high-performance liquid chromatography equipped with a hydrophilic interaction chromatography column was developed. The developed method enabled easy and rapid determination of 1,4-dioxane, even in saline medium. Microbes capable of degrading 1,4-dioxane were selected from the seawater samples by the seawater-charcoal perfusion apparatus. Among 32 candidate 1,4-dioxane degraders,, strain RM-31 exhibited the strongest 1,4-dioxane degradation ability. 16S rDNA sequencing and the similarity analysis of strain RM-31 suggested that this organism was most closely related to Pseudonocardia carboxydivorans. This species is similar to Pseudonocardia dioxanivorans, which has previously been reported as a 1,4-dioxane degrader. Strain RM-31 could degrade 300 mg/L within 2 days. As culture incubation times increasing, the residual 1,4-dioxane concentration was decreasing and the total protein contents extracted from growth cells were increasing. The optimum initial pH of the broth medium and incubation temperature for 1,4-dioxane degradation were pH 6-8 and 25 °C. The biodegradation rate of 1,4-dioxane by strain RM-31 at 25 °C in broth medium with 3 % NaCl was almost 20 % faster than that without NaCl. It was probably a first bacteria from the seawater that can exert a strong degrading ability.

  1. Tools for measuring surface cleanliness

    Energy Technology Data Exchange (ETDEWEB)

    Schroder, Mark Stewart (Hendersonville, NC); Woodmansee, Donald Ernest (Simpsonville, SC); Beadie, Douglas Frank (Greenville, SC)

    2002-01-01

    A procedure and tools for quantifying surface cleanliness are described. Cleanliness of a target surface is quantified by wiping a prescribed area of the surface with a flexible, bright white cloth swatch, preferably mounted on a special tool. The cloth picks up a substantial amount of any particulate surface contamination. The amount of contamination is determined by measuring the reflectivity loss of the cloth before and after wiping on the contaminated system and comparing that loss to a previous calibration with similar contamination. In the alternative, a visual comparison of the contaminated cloth to a contamination key provides an indication of the surface cleanliness.

  2. A rapid automated procedure for laboratory and shipboard spectrophotometric measurements of seawater alkalinity: continuously monitored single-step acid additions

    Science.gov (United States)

    Liu, X.; Byrne, R. H.; Lindemuth, M.; Easley, R. A.; Patsavas, M. C.

    2012-12-01

    An automated system for shipboard and laboratory alkalinity measurements is presented. The simple system, which consists of a Dosimat titrator to deliver acid volumetrically and a USB 4000 spectrophotometer to monitor the titration progress, provides fast, precise and accurate measurements of total alkalinity for oceanographic research. The analytical method is based on single-point HCl titrations of seawater samples of a known volume; bromol cresol purple is used as an indicator to determine the final pH. Field data from an Arctic cruise demonstrates accuracy and precision around 1 micro mol/kg and a sample processing rate of 6 min per sample.

  3. SRB seawater corrosion project

    Science.gov (United States)

    Bozack, M. J.

    1991-01-01

    The corrosion behavior of 2219 aluminum when exposed to seawater was characterized. Controlled corrosion experiments at three different temperatures (30, 60 and 100 C) and two different environments (seawater and 3.5 percent salt solution) were designed to elucidate the initial stages in the corrosion process. It was found that 2219 aluminum is an active catalytic surface for growth of Al2O3, NaCl, and MgO. Formation of Al2O3 is favored at lower temperatures, while MgO is favored at higher temperatures. Visible corrosion products are formed within 30 minutes after seawater exposure. Corrosion characteristics in 3.5 percent salt solution are different than corrosion in seawater. Techniques utilized were: (1) scanning electron microscopy, (2) energy dispersive x-ray spectroscopy, and (3) Auger electron spectroscopy.

  4. Coupled sea surface temperature-seawater delta O-18 reconstructions in the Arabian Sea at the millennial scale for the last 35 ka

    NARCIS (Netherlands)

    Anand, P.; Kroon, D.; Singh, A.D.; Ganssen, G.M.

    2008-01-01

    Two sediment cores from the western (905; 10.46°9′N, 51.56°4′E, water depth 1586 m) and eastern (SK17; 15°15′N, 72°58′E, water depth 840 m) Arabian Sea were used to study past sea surface temperatures (SST) and seawater δ

  5. Mesoscale spatial variability in seawater cavitation thresholds

    Science.gov (United States)

    Mel'nikov, N. P.; Elistratov, V. P.

    2017-03-01

    The paper presents the spatial variability of cavitation thresholds and some hydrological and hydrochemical parameters of seawater in the interfrontal zone of the Pacific Subarctic Front, in the Drake Passage, and in the equatorial part of the Pacific Ocean, measured in the near-surface layer to a depth of 70 m.

  6. Armor Plate Surface Roughness Measurements

    National Research Council Canada - National Science Library

    Stanton, Brian; Coburn, William; Pizzillo, Thomas J

    2005-01-01

    ...., surface texture and coatings) that could become important at high frequency. We measure waviness and roughness of various plates to know the parameter range for smooth aluminum and rolled homogenous armor (RHA...

  7. The application of a plug-flow reactor to measure the biodegradable dissolved organic carbon (BDOC) in seawater.

    Science.gov (United States)

    De Vittor, Cinzia; Larato, Chiara; Umani, Serena Fonda

    2009-12-01

    Most of the ambient dissolved organic carbon (DOC) is refractory to microbial degradation; bacteria can consume a minor but variable part of the DOC pool over periods of hours and days. It is important to increase our knowledge of the dynamics of the biodegradable fraction of DOC (BDOC) to understand the global carbon budget. Several methods for determining BDOC have been developed; however, the problem of most of them is the time (days/weeks) required for the colonization and/or determination. In this paper, we describe the application to seawater of a plug-flow bioreactor to measure BDOC within 3-4 h. The bioreactor was built following Søndergaard and Worm [Søndergaard, M., Worm, J., 2001. Measurement of biodegradable dissolved organic carbon (BDOC) in lake water with a bioreactor. Water Res. 35, 2505-2513.] protocols for the measurement of BDOC in lake water. We analyzed BDOC on samples collected in the Gulf of Trieste during autumn-winter and summer 2003-2004. BDOC concentrations varied from 8 to 24 microM and represented from 10.3% to 25.5% of the total DOC. To evaluate the effectiveness of this method, we compared bioreactor BDOC measurement with data obtained from batch cultures. The results indicate that BDOC in coastal seawater can be measured rapidly and reliably with this bioreactor.

  8. [Measurements of surface ocean carbon dioxide partial pressure during WOCE

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    This paper discusses the research progress of the second year of research under Measurement of Surface Ocean Carbon Dioxide Partial Pressure During WOCE'' and proposes to continue measurements of underway pCO[sub 2]. During most of the first year of this grant, our efforts to measure pCO[sub 2] on WOCE WHP legs were frustrated by ship problems. The R/V Knorr, which was originally scheduled to carry out the first work on WHP lines P19 and P16 in the southeastem Pacific during the 1990-91 austral summer, was delayed in the shipyard during her mid-life refit for more than a year. In the interim, the smaller R/V Thomas Washington, was pressed into service to carry out lower-latitude portions of WHP lines P16 and P17 during mid-1991 (TUNES Expedition). We installed and operated our underway chromatographic system on this expedition, even though space and manpower on this smaller vessel were limited and no one from our group would be aboard any of the 3 WHP expedition legs. The results for carbon dioxide and nitrous oxide are shown. A map of the cruise track is shown for each leg, marked with cumulative distance. Following each track is a figure showing the carbon dioxide and nitrous oxide results as a function of distance along this track. The results are plotted as dry-gas mole fractions (in ppm and ppb, respectively) in air and in gas equilibrated with surface seawater at a total pressure equal to the barometric pressure. The air data are plotted as a 10-point running mean, and appear as a roughly horizontal line. The seawater data are plotted as individual points, using a 5-point Gaussian smoother. Equal values Of xCO[sub 2] in air and surface seawater indicate air-sea equilibrium.

  9. Surface modification of commercial seawater reverse osmosis membranes by grafting of hydrophilic monomer blended with carboxylated multiwalled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Vatanpour, Vahid, E-mail: vahidvatanpour@khu.ac.ir; Zoqi, Naser

    2017-02-28

    Highlights: • A commercial PA RO membrane was modified by grafting of hydrophilic acrylic acid. • COOH-MWCNTs were mixed in grafting layer to increase permeability and antifouling. • However, more increase of CNTs caused in reduction of flux of the membranes. • Effect of acrylic acid amount, contact time and curing time was optimized. - Abstract: In this study, modification of commercial seawater reverse osmosis membranes was carried out with simultaneous use of surface grafting and nanoparticle incorporation. Membrane grafting with a hydrophilic acrylic acid monomer and thermal initiator was used to increase membrane surface hydrophilicity. The used nanomaterial was carboxylated multiwalled carbon nanotubes (MWCNTs), which were dispersed in the grafting solution and deposited on membrane surface to reduce fouling by creating polymer brushes and hydrodynamic resistance. Effectiveness of the grafting process (formation of graft layer on membrane surface) was proved by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses. Increase of membrane surface hydrophilicity was approved with contact angle test. First, the grafting was performed on the membrane surfaces with different monomer concentrations, various contact times and several membrane curing times (three variables for optimization). The modified membranes were tested by a cross-flow setup using saline solution for permeability and rejection tests, and bovine serum albumin (BSA) solution for fouling test. The results showed that the modified membranes with 0.75 M of monomer, 3 min contact time and 80 min curing time in an oven at 50 °C presented the highest flux and lowest rejection decline related to the commercial reverse osmosis membrane. In the next step, the optimum grafting condition was selected and the nanotubes with different weight percentages were dispersed in the acrylic acid monomer solution. The membrane containing 0.25 wt% COOH-MWCNTs showed the

  10. Toxicity of Single and Mixed Contaminants in Seawater Measured with Acute Toxicity Bioassays

    Directory of Open Access Journals (Sweden)

    A.R. Fernandez-Alba

    2002-01-01

    Full Text Available Different types of organic pollutants commonly detected in seawater have been evaluated by acute toxicity bioassays. Vibrio fischeri, Daphnia magna, and Selenastrum capricornotum were selected to test toxic effects of individual compounds and mixtures of these compounds, obtaining EC50 values in the range of 0.001 to 28.9 mg/l. In the case of mixtures, synergistic toxic responses were seen for a clear majority of the cases (>60%. Mixtures containing methyl-tertiary-butyl ether (MTBE exhibit accelerated processes that result in a change in concentration required to produce a toxic effect; for example, in the case of mixtures containing MTBE and Diuron and Dichlofluanid.

  11. Direct observation of 134Cs and 137Cs in surface seawater in the western and central North Pacific after the Fukushima Dai-ichi nuclear power plant accident

    Directory of Open Access Journals (Sweden)

    H. Kaeriyama

    2013-06-01

    Full Text Available The horizontal distribution of radioactive cesium (Cs derived from the Fukushima Dai-ichi nuclear power plant (FNPP in the North Pacific is still unclear due to the limitation of direct measurement of the seawater in the open ocean. We present the result of direct observation of radioactive Cs in surface seawater collected from a broad area in the western and central North Pacific in July 2011, October 2011 and July 2012. We also conducted a simple particle tracking experiment to estimate the qualitative spatial distribution of radioactive Cs in the North Pacific. 134Cs was detected at 94 stations out of 123 stations, and 137Cs was detected at all stations. High 134Cs and 137Cs concentrations more than 10 m Bq kg−1 were observed in the area of the northern part of Kuroshio Extension at 144° E and 155° E in July 2011, in the area 147–175° E around 40° N in October 2011, and the northern part of Kuroshio Extension at 155° E and 175°30´ E in July 2012. Combining the result of direct observations and particle tracking experiment, the radioactive Cs derived from the FNPP had been dispersed eastward to the central North Pacific during 2011. It was considered from the horizontal distribution that radioactive Cs was dispersed not only eastward but also north- and southward in the central North Pacific. Pronounced dilution process of radioactive Cs from the FNPP during study period is suggested from temporal change in the activity ratio of 134Cs / 137Cs, which was decay-corrected on 6 April 2011, and relationships between radioactive Cs and temperature.

  12. Uranium from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Gregg, D.; Folkendt, M.

    1982-09-21

    A novel process for recovering uranium from seawater is proposed and some of the critical technical parameters are evaluated. The process, in summary, consists of two different options for contacting adsorbant pellets with seawater without pumping the seawater. It is expected that this will reduce the mass handling requirements, compared to pumped seawater systems, by a factor of approximately 10/sup 5/, which should also result in a large reduction in initial capital investment. Activated carbon, possibly in combination with a small amount of dissolved titanium hydroxide, is expected to be the preferred adsorbant material instead of the commonly assumed titanium hydroxide alone. The activated carbon, after exposure to seawater, can be stripped of uranium with an appropriate eluant (probably an acid) or can be burned for its heating value (possible in a power plant) leaving the uranium further enriched in its ash. The uranium, representing about 1% of the ash, is then a rich ore and would be recovered in a conventional manner. Experimental results have indicated that activated carbon, acting alone, is not adequately effective in adsorbing the uranium from seawater. We measured partition coefficients (concentration ratios) of approximately 10/sup 3/ in seawater instead of the reported values of 10/sup 5/. However, preliminary tests carried out in fresh water show considerable promise for an extraction system that uses a combination of dissolved titanium hydroxide (in minute amounts) which forms an insoluble compound with the uranyl ion, and the insoluble compound then being sorbed out on activated carbon. Such a system showed partition coefficients in excess of 10/sup 5/ in fresh water. However, the system was not tested in seawater.

  13. Distribution of lead-210 and polonium-210 between soluble and particulate phases in seawater

    International Nuclear Information System (INIS)

    Spencer, D.W.

    1975-01-01

    Results are reported from radiometric measurements of the distribution of 210 Pb and 210 Po in surface seawater and suspended particulate matter. Samples of plankton and sediments collected from some locations were also analyzed. Samples of seawater and suspended particulate matter were collected from stations located in the Gulf of Maine, the North Atlantic, and approximately 500 miles southwest of Gilbraltar. (U.S.)

  14. Dynamics of amino acids in the conditioning film developed on glass panels immersed in the surface seawaters of Dona Paula Bay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Garg, A.; Fernandes, L.; Citon, P.

    adsorption of dissolved organic and/or inorganic matter, is defined as the conditioning film or the molecular film (Baier, 1972; Loeb & Neihof, 1975; Taylor et al. 1997). The adsorbed organic matter forms a discontinuous film of variable thickness (Compere et..., Goa, India, and 2 Ecole Nationale Superieure d’Ingenieures, De Limoges, Limoges, France (Received 13 October 2004; accepted 17 February 2005) Abstract The conditioning film developed on glass panels immersed in surface seawater over a period of 24 h...

  15. Oceans circulation and electron cyclotron resonance sources: Measurement of the AR-39 isotopic ratio in Seawater

    International Nuclear Information System (INIS)

    Gaelens, M.; Loiselet, M.; Ryckewaert, G.; Pardo, R.C.; Scott, R.H.; Vondrasek, R.; Collon, Ph.; Kutchera, W.

    2004-01-01

    The radionuclide 39 Ar is produced in the atmosphere by cosmic rays and has an isotopic abundance of 8.1x10 -16 . Because its half life (T 1/2 =269 years) is well matched to the time periods involved in the oceanic currents around the Earth, the measurement of the 39 Ar isotopic ratio is an ideal tool to date ocean water from different depths. It would complement the information gained by the 14 C measurements (T 1/2 =5730 years). However, the measurement of the isotopic ratio 39 Ar/ 40 Ar is a technical challenge: 1 L of modern ocean water contains ∼6500 atoms of 39 Ar, and produces ∼17 decays per year. Although it has been possible to detect the 39 Ar decays in large volumes of sea water by using the low level counting technique, the possibility of measuring the number of 39 Ar atoms faster and in smaller samples using the accelerator mass spectrometry (AMS) technique would be a major breakthrough for this type of measurement. The development of a viable AMS method for 39 Ar has been underway for several years at Argonne National Laboratory, and is presently hampered by the presence of stable 39 K ions coming from the ion source. Although the intensity of this isobaric contaminant is low (∼pA extracted from the source), it has to be compared with the 39 Ar beam intensity (atoms per minutes). In order to separate these two beams (whose mass difference is only 1.6x10 -5 ), the intensity of the 39 K beam coming from the ion source has to be reduced by several orders of magnitude. This reduction has been investigated both at Argonne National Laboratory and at Louvain-la-Neuve. Two techniques have been tried out. In the first, a quartz liner is used to provide a clean surface, while in the second these impurities are buried in a SiO 2 layer formed in situ by running the source with a mixture of silane and oxygen. The 39 K background has been reduced by a factor of 100 with these treatments. These techniques and their results obtained both at Argonne and Louvain

  16. A high-resolution analyser for the measurement of ammonium in oligotrophic seawater

    Science.gov (United States)

    Abi Kaed Bey, Samer K.; Connelly, Douglas P.; Legiret, François-Eric; Harris, Andy J. K.; Mowlem, Matthew C.

    2011-10-01

    In this work, we describe a high-resolution fluorometric shipboard analyser and an improved method to determine NH{4/+} in oligotrophic seawater. The limit of detection is sulfite. Due to the high resolution of the developed system, we were able to study in depth the sensitivity of the method to salinity, amines, amino acids and potential interferences from particles/algae. The method was found to be sensitive to salinity variations, reducing the signal by up to 85% at 5 nM; this effect decreased at higher concentrations of ammonium. It was noted that the interference from amines at low concentrations was negligible; however, at either high amino acid or high amine concentrations, the signal was depressed. To test for the effect of particles on the system, the system was tested with samples containing phytoplankton ( Dunaliella primolecta) cells at different concentrations prepared with ASW to simulate the effect of a phytoplankton bloom. This experiment assessed the potential impact of both particles and other potential fluorescence interferences from cells and/or ammonium leaching from cells. This experiment showed that a phytoplankton bloom could potentially have an impact of up to 12% on the signal of interest. Thus, we propose that this method is suitable for oligotrophic environments rather than coastal and eutrophic environments. The reagent was found to be stable for 17 days and standards of 1 μM were stable for 6 days under laboratory conditions. The developed analyser was successfully demonstrated in the North Atlantic Ocean, in an area of oligotrophic, low NH{4/+} oceanic waters.

  17. Temperature profile data from surface seawater intake, bucket, and XBT casts in a world wide distribution from 1994-06-29 to 1996-06-08 (NODC Accession 9600120)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using surface seawater intake, bucket, and XBT casts from multiple vessels in a world wide distribution from June 29, 1994 to...

  18. Temperature profile data from surface seawater intake, bucket, and XBT casts in a world wide distribution from 1995-02-24 to 1996-06-23 (NODC Accession 9700060)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using surface seawater intake, bucket, and XBT casts from several vessels in a world wide distribution from February 24,...

  19. Effective removal of ammonia nitrogen from waste seawater using crystal seed enhanced struvite precipitation technology with response surface methodology for process optimization.

    Science.gov (United States)

    Song, Weilong; Li, Zhipeng; Liu, Feng; Ding, Yi; Qi, Peishi; You, Hong; Jin, Chao

    2018-01-01

    Traditional biological treatment was not effective for removing nitrogen from saline wastewater due to the inhibition of high salinity on biomass activity. In this context, a method of removing ammonia nitrogen from waste seawater was proposed by struvite precipitation which was enhanced by seeding technique. The abundant magnesium contained in waste seawater was used as the key component of struvite crystallization without additional magnesium. The effects of pH and P:N molar ratio on ammonia nitrogen removal efficiency were studied. The results showed that optimum pH value was in range of 8.5-10 and the P:N molar ratio should be controlled within 2:1-3:1. XRD and SEM-EDS analyses of the precipitates proved that Ca 2+ and excess Mg 2+ contained in waste seawater inhibited the struvite crystallization by competing PO 4 3- to form by-products. Then, seeding technique for enhancing the struvite crystallization was investigated, and the results indicated that using preformed struvite as crystal seed significantly improved the ammonia nitrogen removal efficiency, especially when initial ammonia nitrogen concentration was relatively low. Moreover, response surface optimization experiment following a Box-Behnken design was conducted. A response surface model was established, based on which optimum process conditions were determined and interactions between various factors were clarified. At last, economic evaluation demonstrated this proposed method was economic feasible.

  20. Ecological risk assessment of heavy metals in surface seawater and sediment near the outlet of a zinc factory in Huludao City, Liaoning Province, China

    Science.gov (United States)

    Feng, Yongliang; Chen, Yanzhen; Wang, Jing; Gong, Yufeng; Liu, Xigang; Mu, Gang; Tian, Hua

    2016-11-01

    At present, the methods widely applied to assess ecological risk of heavy metals are essentially single-point estimates in which exposure and toxicity data cannot be fully used and probabilities of adverse biological eff ects cannot be achieved. In this study, based on investigation of concentrations of six heavy metals (As, Hg, Pb, Cd, Cu, and Zn) in the surface seawater and sediment near the outlet of a zinc factory, located in Huludao City, Liaoning Province, China, a tiered approach consisting of several probabilistic options was used to refine ecological risk assessment for the individuals. A mixture of various heavy metals was detected in the surface seawater, and potential ecological risk index (PERI) was adopted to assess the potential ecological risk of heavy metals in the surface sediment. The results from all levels of aquatic ecological risk assessment in the tiered framework, ranging from comparison of single eff ects and exposure values to the use of distribution-based Hazard Quotient obtained through Monte Carlo simulation, are consistent with each other. Briefly, aquatic Zn and Cu posed a clear ecological risk, while Cd, Pb, Hg, and As in the water column posed potential risk. As expected, combined ecological risk of heavy metal mixture in the surface seawater was proved significantly higher than the risk caused by any individual heavy metal, calculated using the concept of total equivalent concentration. According to PERI, the severity of pollution by the six heavy metals in the surface sediment decreased in the following sequence: Cd>Hg>As>Pb>Cu>Zn, and the total heavy metals in the sediment posed a very high risk to the marine environment. This study provides a useful mathematical framework for ecological risk assessment of heavy metals.

  1. Spatial variations in microbial community composition in surface seawater from the ultra-oligotrophic center to rim of the South Pacific Gyre.

    Directory of Open Access Journals (Sweden)

    Qi Yin

    Full Text Available Surface seawater in the South Pacific Gyre (SPG is one of the cleanest oceanic environments on earth, and the photosynthetic primary production is extremely low. Despite the ecological significance of the largest aquatic desert on our planet, microbial community composition in the ultra-oligotrophic seawater remain largely unknown. In this study, we collected surface seawater along a southern transect of the SPG during the Integrated Ocean Drilling Program (IODP Expedition 329. Samples from four distinct sites (Sites U1368, U1369, U1370 and U1371 were examined, representing ~5400 kilometers of transect line from the gyre heart to the edge area. Real-time PCR analysis showed 16S rRNA gene abundance in the gyre seawater, ranging from 5.96×10(5 to 2.55×10(6 copies ml(-1 for Bacteria and 1.17×10(3 to 1.90×10(4 copies ml(-1 for Archaea. The results obtained by statistic analyses of 16S rRNA gene clone libraries revealed the community composition in the southern SPG area: diversity richness estimators in the gyre center (Sites U1368 & U1369 are generally lower than those at sites in the gyre edge (Sites U1370 & U1371 and their community structures are clearly distinguishable. Phylogenetic analysis showed the predominance of Proteobacteria (especially Alphaproteobacteria and Cyanobacteria in bacterial 16S rRNA gene clone libraries, whereas phylotypes of Betaproteobacteria were only detected in the central gyre. Archaeal 16S rRNA genes in the clone libraries were predominated by the sequences of Marine Group II within the Euryarchaeota, and the Crenarchaeota sequences were rarely detected, which is consistent with the real-time PCR data (only 9.9 to 22.1 copies ml(-1. We also performed cultivation of heterotrophic microbes onboard, resulting in 18.9% of phylogenetically distinct bacterial isolates at least at the species level. Our results suggest that the distribution and diversity of microbial communities in the SPG surface seawater are closely

  2. Extraction of uranium from seawater

    International Nuclear Information System (INIS)

    Katoh, Shunsaku; Sugasaka, Kazuhiko

    1982-01-01

    70 % of the earth surface is covered by sea, and the total quantity of seawater is 1.4 x 10 18 m 3 . More than 70 elements are contained in seawater, but only salt, magnesium, gypsum and bromine with relatively high concentration have been utilized so far. The uranium concentration in seawater is as low as 3 ppb, but as the total amount, 4 billion tons are dissolved in seawater. The estimated uranium deposit on land which can be mined at the cost below $130/kg is 2.6 million tons, and its depletion may come by the end of this century. Only ion exchange method is usable as the economically feasible method of extracting uranium from natural water, and the enrichment factor must be more than 10 5 . FThe research on uranium extraction from water performed so far is reviewed. In the Government Industrial Research Institute, Shikoku, it was found that the compound adsorbent of titanium-activated carbon was excellent for the purpose, and by this method, it successfully extracted 0.7 g of uranium from seawater in 1978. The adsorption method is considered to be most easily realizable in view of the rate of recovery of uranium, easy handling, the stability in seawater and so on. The present status and future prospect of the research on uranium extraction from seawater are reported. (Kako, I.)

  3. Measurements of Near Sea Surface Infrared Propagation

    National Research Council Canada - National Science Library

    Frost, Shaun

    1999-01-01

    .... Measurements have been made of the atmospheric infrared transmission near the sea surface. Spectral transmission profiles were measured for a number of ranges using a fourier transform spectrometer...

  4. The measurement of surface gravity

    International Nuclear Information System (INIS)

    Crossley, David; Hinderer, Jacques; Riccardi, Umberto

    2013-01-01

    This review covers basic theory and techniques behind the use of ground-based gravimetry at the Earth's surface. The orientation is toward modern instrumentation, data processing and interpretation for observing surface, land-based, time-variable changes to the geopotential. The instrumentation side is covered in some detail, with specifications and performance of the most widely used models of the three main types: the absolute gravimeters (FG5, A10 from Micro-g LaCoste), superconducting gravimeters (OSG, iGrav from GWR instruments), and the new generation of spring instruments (Micro-g LaCoste gPhone, Scintrex CG5 and Burris ZLS). A wide range of applications is covered, with selected examples from tides and ocean loading, atmospheric effects on gravity, local and global hydrology, seismology and normal modes, long period and tectonics, volcanology, exploration gravimetry, and some examples of gravimetry connected to fundamental physics. We show that there are only a modest number of very large signals, i.e. hundreds of µGal (10 −8 m s −2 ), that are easy to see with all gravimeters (e.g. tides, volcanic eruptions, large earthquakes, seasonal hydrology). The majority of signals of interest are in the range 0.1–5.0 µGal and occur at a wide range of time scales (minutes to years) and spatial extent (a few meters to global). Here the competing effects require a careful combination of different gravimeter types and measurement strategies to efficiently characterize and distinguish the signals. Gravimeters are sophisticated instruments, with substantial up-front costs, and they place demands on the operators to maximize the results. Nevertheless their performance characteristics such as drift and precision have improved dramatically in recent years, and their data recording ability and ruggedness have seen similar advances. Many subtle signals are now routinely connected with known geophysical effects such as coseismic earthquake displacements, post

  5. The measurement of surface gravity

    Science.gov (United States)

    Crossley, David; Hinderer, Jacques; Riccardi, Umberto

    2013-04-01

    This review covers basic theory and techniques behind the use of ground-based gravimetry at the Earth's surface. The orientation is toward modern instrumentation, data processing and interpretation for observing surface, land-based, time-variable changes to the geopotential. The instrumentation side is covered in some detail, with specifications and performance of the most widely used models of the three main types: the absolute gravimeters (FG5, A10 from Micro-g LaCoste), superconducting gravimeters (OSG, iGrav from GWR instruments), and the new generation of spring instruments (Micro-g LaCoste gPhone, Scintrex CG5 and Burris ZLS). A wide range of applications is covered, with selected examples from tides and ocean loading, atmospheric effects on gravity, local and global hydrology, seismology and normal modes, long period and tectonics, volcanology, exploration gravimetry, and some examples of gravimetry connected to fundamental physics. We show that there are only a modest number of very large signals, i.e. hundreds of µGal (10-8 m s-2), that are easy to see with all gravimeters (e.g. tides, volcanic eruptions, large earthquakes, seasonal hydrology). The majority of signals of interest are in the range 0.1-5.0 µGal and occur at a wide range of time scales (minutes to years) and spatial extent (a few meters to global). Here the competing effects require a careful combination of different gravimeter types and measurement strategies to efficiently characterize and distinguish the signals. Gravimeters are sophisticated instruments, with substantial up-front costs, and they place demands on the operators to maximize the results. Nevertheless their performance characteristics such as drift and precision have improved dramatically in recent years, and their data recording ability and ruggedness have seen similar advances. Many subtle signals are now routinely connected with known geophysical effects such as coseismic earthquake displacements, post-glacial rebound

  6. Gas exchange at the air-sea interface: a technique for radon measurements in seawater

    International Nuclear Information System (INIS)

    Queirazza, G.; Roveri, M.

    1991-01-01

    The rate of exchange of various gas species, such as O 2 , CO 2 etc. across the air-water interface can be evaluated from the 222 Rn vertical profiles in the water column. Radon profiles were measured in 4 stations in the NW Adriatic Sea, in September 1990, using solvent extraction and liquid scintillation counting techniques, directly on board the ship. The radiochemical procedure is described in detail. The lower limit of detection is approximately 0.4 mBq 1 -1 . The radon deficiency in the profiles gives estimates of the gas transfer rate across the air-sea interface ranging from 0.9 to 7.0 m d -1 . The suitability of the radon deficiency method in shallow water, enclosed seas is briefly discussed. (Author)

  7. Chemical effect on ozone deposition over seawater

    Science.gov (United States)

    Surface layer resistance plays an important role in determining ozone deposition velocity over seawater. Recent studies suggest that surface layer resistance over sea-water is influenced by wind-speed and chemical interaction at the air-water interface. Here, we investigate the e...

  8. Spatial distributions of (137)Cs and (239+240)Pu in surface seawater within the Exclusive Economic Zone of East Coast Peninsular Malaysia.

    Science.gov (United States)

    Ahmad, Zaharudin; Mei-Wo, Yii; Abu Bakar, Ahmad Sanadi; Shahar, Hidayah

    2010-09-01

    The studies of (137)Cs and (239+240)Pu distributions in surface seawater at South China Sea within the Exclusive Economic Zone (EEZ) of Peninsular Malaysia were carried out in June 2008. The analysis results will serve as additional information to the expanded baseline data for Malaysia's marine environment. Thirty locations from extended study area were identified in the EEZ from which large volumes of surface seawater samples were collected. Different co-precipitation techniques were employed to concentrate cesium and plutonium separately. A known amount of (134)Cs and (242)Pu tracers were used as yield determinant. The precipitate slurry was collected and oven dried at 60(o)C for 1-2 days. Cesium precipitate was fine-ground and counted using gamma-ray spectrometry system at 661.62keV, while plutonium was separated from other radionuclides using anion exchange, electrodeposited and counted using alpha spectrometry. The activity concentrations of (137)Cs and (239+240)Pu were in the range of 3.40-5.89Bq/m(3) and 2.3-7.9mBq/m(3), respectively. The (239+240)Pu/(137)Cs ratios indicate that there are no new inputs of these radionuclides into the area.

  9. Measuring Surface Combatant Fleet Effectiveness

    National Research Council Canada - National Science Library

    Crary, Michael

    1999-01-01

    ...? While Measures of Effectiveness for an individual ship can include its number of missiles, speed, and endurance, it is difficult to find a Measure of Effectiveness credible to experienced warplanners...

  10. Impact of the surface roughness of AISI 316L stainless steel on biofilm adhesion in a seawater-cooled tubular heat exchanger-condenser.

    Science.gov (United States)

    García, Sergio; Trueba, Alfredo; Vega, Luis M; Madariaga, Ernesto

    2016-11-01

    The present study evaluated biofilm growth in AISI 316L stainless steel tubes for seawater-cooled exchanger-condensers that had four different arithmetic mean surface roughness values ranging from 0.14 μm to 1.2 μm. The results of fluid frictional resistance and heat transfer resistance regarding biofilm formation in the roughest surface showed increases of 28.2% and 19.1% respectively, compared with the smoothest surface. The biofilm thickness taken at the end of the experiment showed variations of up to 74% between the smoothest and roughest surfaces. The thermal efficiency of the heat transfer process in the tube with the roughest surface was 17.4% greater than that in the tube with the smoothest surface. The results suggest that the finish of the inner surfaces of the tubes in heat exchanger-condensers is critical for improving energy efficiency and avoiding biofilm adhesion. This may be utilised to reduce biofilm adhesion and growth in the design of heat exchanger-condensers.

  11. Analysis by the IRSN of the Tritium concentration measured by the ACRO in a seawater sampling from the Ecalgrain bay on the 17 October 2012

    International Nuclear Information System (INIS)

    2013-01-01

    As the ACRO published a result of seawater analysis performed on a sample taken in the Ecalgrain bay at the vicinity of the La Hague plant (this analysis revealed a very high level of Tritium in seawater), this document reports and comments the results obtained by the nearest IRSN measurement station since 1997. The authors outline the complex influence of numerous factors (meteorological conditions, sea currents, tides, and so on). They present the results obtained by a computation code which has been developed to predict the dispersion of La Hague releases. They compare the levels thus computed and the results published by the ACRO, and state that important differences may exist between two relatively close sites due to meteorological and sea conditions

  12. Neodymium isotopic variations in seawater

    International Nuclear Information System (INIS)

    Piepgras, D.J.; Wasserburg, G.J.

    1980-01-01

    New data for the direct measurement of the isotopic composition of neodymium in Atlantic Ocean seawater are compared with previous measurements of Pacific Ocean seawater and ferromanganese sediments from major ocean basins. Data for Atlantic seawater are in excellent agreement with Nd isotopic measurements made on Atlantic ferromanganese sediments and are distinctly different from the observed compositions of Pacific samples. These results clearly demonstrate the existence of distinctive differences in the isotopic composition of Nd in the waters of the major ocean basins and are characteristic of the ocean basin sampled. The average epsilonsub(N)sub(d)(0) values for the major oceans as determined by data from seawater and ferromanganese sediments are as follows: Atlantic Ocean, epsilonsub(N)sub(d)(0) approx. equal to - 12 +- 2; Indian Ocean, epsilonsub(N)sub(d)(0) approx. equal to - 8 +- 2; Pacific Ocean, epsilonsub(N)sub(d)(0) approx. equal to -3 +- 2. These values are considerably less than epsilonsub(N)sub(d)(0) value sources with oceanic mantle affinities indicating that the REE in the oceans are dominated by continental sources. The difference in the absolute abundance of 143 Nd between the Pacific and Atlantic Oceans corresponds to approx. 10 6 atoms 143 Nd per gram of seawater. The correspondence between the 143 Nd/ 144 Nd in seawater and in the associated sediments suggests the possible application of this approach to paleo-oceanography. (orig./HAE)

  13. Impregnation/Agglomeration Laboratory Tests of Heavy Fuel from Prestige to Improve Its Manageability and Removal from Seawater Surface. (Physical Behaviour of Fuel Agglomates)

    International Nuclear Information System (INIS)

    Garcia Frutos, F. J.; Rodriguez, V.; Otero, J.

    2002-01-01

    The handling and removal problems showed by heavy fuel floating in seawater could be improved or solved by using materials that agglomerate it. These materials must fulfill the following conditions: be inert materials in marine environment, the agglomerated fuel/material should float and its application and removal should be done using simple technologies. Based on these requirements, clay minerals, pine chips, mineral coal and charcoal were selected. The preliminary/results on impregnation/agglomeration with the materials mentioned above of heavy fuel from Prestige at lab scale are presented in this paper. The results have shown that only hydrophobic materials, such as mineral coal and charcoal, are able to agglomerate with fuel, which is also a hydrophobic substance. Whereas the agglomerates fuel/mineral coal sink, the agglomerates fuel/charcoal keep floating on water surface. It can be concluded that the addition of charcoal on dispersed fuel in seawater could improve its handling and removal. In this sense, pilot scale and eventually controlled in situ tests to study the feasibility of the proposed solution should be performed. (Author) 2 refs

  14. Surface charge measurement by the Pockels effect

    CERN Document Server

    Sam, Y L

    2001-01-01

    have been observed by applying both impulse and AC voltages to a needle electrode in direct contact with the BSO. AC surface discharge behaviour of polymeric materials bonded to the BSO has also been investigated. The effect of the surrounding environment has been experimentally examined by placing the cell inside a vacuum chamber. Surface charge measurements have been made at various atmospheric pressures. The effect of an electro-negative gas (Sulphur Hexafluoride) on the surface charge distribution has also been investigated. This thesis is concerned with the design and development of a surface charge measurement system using Pockels effect. The measurement of surface charge is important in determining the electrical performance of high voltage insulation materials. The method proposed allows on-line measurement of charge and can generate two-dimensional images that represent the charge behaviour on the surface of the material under test. The measurement system is optical and uses a Pockels crystal as the ...

  15. Absorption-based highly sensitive and reproducible biochemical oxygen demand measurement method for seawater using salt-tolerant yeast Saccharomyces cerevisiae ARIF KD-003.

    Science.gov (United States)

    Nakamura, Hideaki; Mogi, Yotaro; Hattori, Hisashi; Kita, Yutaka; Hattori, Daisuke; Yoshimura, Aki; Karube, Isao

    2008-07-14

    Salt-tolerant yeast Saccharomyces cerevisiae ARIF KD-003 was applied to highly sensitive and reproducible absorbance-based biochemical oxygen demand (BOD(AB-ScII)) measurement for seawater. In the previous work, we have studied the BOD(AB-ScI) method using normal Baker's yeast S. cerevisiae, and the excellent feature of the Baker's yeast as uniformly sustainable in solution could successfully be utilized. However, the BOD(AB-ScI) responses were disappeared by the existence of chloride ion as well as seawater. In the present method, uniformity in solution was also observed with S. cerevisiae ARIF KD-003, and salt-tolerance of the yeast was observed even in saturate concentration of sodium chloride. Next, characterizations of the influences of pH and incubation temperature were investigated. After optimum conditions were obtained, two calibration curves were made between 0.33 and 22 mg O2 L(-1) BOD using standard solution of glucose glutamic acid (GGA) or mixture of GGA and artificial seawater. Then, excellent reproducibility as the averages of relative standard deviation (R.S.D.(av)) in two calibration curves (nine points each) was successfully obtained at 1.10% at pure water or 1.03% at artificial seawater standard, respectively. In addition, the 3 sigma lower detection limit was calculated to be 0.07 mg O2 L(-1) BOD, and 0.11 mg O2 L(-1) BOD was experimentally detected by increase of the sample volume at 1.5-folds. The storage stability of the S. cerevisiae ARIF KD-003 was obtained at least 4 weeks.

  16. Contact area measurements on structured surfaces

    DEFF Research Database (Denmark)

    Kücükyildiz, Ömer Can; Jensen, Sebastian Hoppe Nesgaard; De Chiffre, Leonardo

    In connection with the use of brass specimens featuring structured surfaces in a tribology test, an algorithm was developed for automatic measurement of the contact area by optical means.......In connection with the use of brass specimens featuring structured surfaces in a tribology test, an algorithm was developed for automatic measurement of the contact area by optical means....

  17. First investigation of trace metal distribution in surface seawater and copepods of the south coast of Sfax (Tunisia).

    Science.gov (United States)

    Ben Salem, Zohra; Ayadi, Habib

    2017-08-01

    The increased metal loading from anthropogenic sources has affected aquatic ecosystems and has cascaded through food webs worldwide. Therefore, the evaluation of ecological impacts of anthropogenic metal has become increasingly important. In this paper, we monitored the concentration of six trace metals (Cd, Cu, Fe, Ni, Pb, and Zn) in the three copepod groups (cyclopoida, calanoida, and harpacticoida) and in seawater samples collected from the south coast of Sfax (Tunisia). Results showed that the concentration of Fe and Zn for all copepod groups was higher than that for other metals and that of Cd was the lowest in all groups. The mean increase in bioconcentration factor of metals in copepods ranged from 0.05 to 18.93 and followed the sequence Zn (18.93) > Fe (14.34) > Pb (6.41) > Cd (1.53) > Cu (0.10) > Ni (0.05). The copepods in the south coast of Sfax were found to have a great capacity to accumulate trace metals and act as contamination indicators. Comparative studies with those from the Luza zone indicate considerable bioaccumulation of trace metals (Pb and Ni) in all copepod groups namely in cyclopoida.

  18. Surface texture measurement for dental wear applications

    Science.gov (United States)

    Austin, R. S.; Mullen, F.; Bartlett, D. W.

    2015-06-01

    The application of surface topography measurement and characterization within dental materials science is highly active and rapidly developing, in line with many modern industries. Surface measurement and structuring is used extensively within oral and dental science to optimize the optical, tribological and biological performance of natural and biomimetic dental materials. Although there has historically been little standardization in the use and reporting of surface metrology instrumentation and software, the dental industry is beginning to adopt modern areal measurement and characterization techniques, especially as the dental industry is increasingly adopting digital impressioning techniques in order to leverage CAD/CAM technologies for the design and construction of dental restorations. As dental treatment becomes increasingly digitized and reliant on advanced technologies such as dental implants, wider adoption of standardized surface topography and characterization techniques will become evermore essential. The dental research community welcomes the advances that are being made in surface topography measurement science towards realizing this ultimate goal.

  19. Technique for measuring very high surface velocities

    International Nuclear Information System (INIS)

    Maron, Y.

    1977-01-01

    An interferometric technique for measuring displacements of surfaces moving at velocities in the range of a few millimeters per microsecond is presented. The Doppler shift of frequency of light scattered from such surfaces is too high to be detectable by known devices. The present technique is based upon monitoring the signal resulting from the interference between two beams reflected from the surface at different incidence angles. Measurement systems for specularly as well as diffusely reflecting surfaces are described. Light source with very modest temporal coherence delivering about 100 mw power is required. The accuracy of the technique is discussed. (author)

  20. Surface texture measurement for additive manufacturing

    International Nuclear Information System (INIS)

    Triantaphyllou, Andrew; Tomita, Ben; Milne, Katherine A; Giusca, Claudiu L; Macaulay, Gavin D; Roerig, Felix; Hoebel, Matthias; Leach, Richard K

    2015-01-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting. (paper)

  1. Constructing invariant fairness measures for surfaces

    DEFF Research Database (Denmark)

    Gravesen, Jens; Ungstrup, Michael

    2002-01-01

    The paper proposes a rational method to derive fairness measures for surfaces. It works in cases where isophotes, reflection lines, planar intersection curves, or other curves are used to judge the fairness of the surface. The surface fairness measure is derived by demanding that all the given cu...... of curves. Six basic third order invariants by which the fairing measures can be expressed are defined. Furthermore, the geometry of a plane intersection curve is studied, and the variation of the total, the normal, and the geodesic curvature and the geodesic torsion is determined....

  2. Surface tension measurements with a smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-11-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept of surface tension through simple experiments.

  3. Constructing Invariant Fairness Measures for Surfaces

    DEFF Research Database (Denmark)

    Gravesen, Jens; Ungstrup, Michael

    1998-01-01

    This paper presents a general method which from an invariant curve fairness measure constructs an invariant surface fairness measure. Besides the curve fairness measure one only needs a class of curves on the surface for which one wants to apply the curve measure. The surface measure at a point...... variation.The method is extended to the case where one considers, not the fairness of one curve, but the fairness of a one parameter family of curves. Such a family is generated by the flow of a vector field, orthogonal to the curves. The first, respectively the second order derivative along the curve...... of the size of this vector field is used as the fairness measure on the family.Six basic 3rd order invariants satisfying two quadratic equations are defined. They form a complete set in the sense that any invariant 3rd order function can be written as a function of the six basic invariants together...

  4. Preparation of stable silica surfaces for surface forces measurement

    Science.gov (United States)

    Ren, Huai-Yin; Mizukami, Masashi; Kurihara, Kazue

    2017-09-01

    A surface forces apparatus (SFA) measures the forces between two surfaces as a function of the surface separation distance. It is regarded as an essential tool for studying the interactions between two surfaces. However, sample surfaces used for the conventional SFA measurements have been mostly limited to thin (ca. 2-3 μm) micas, which are coated with silver layers (ca. 50 nm) on their back, due to the requirement of the distance determination by transmission mode optical interferometry called FECO (fringes of equal chromatic order). The FECO method has the advantage of determining the absolute distance, so it should be important to increase the availability of samples other than mica, which is chemically nonreactive and also requires significant efforts for cleaving. Recently, silica sheets have been occasionally used in place of mica, which increases the possibility of surface modification. However, in this case, the silver layer side of the sheet is glued on a cylindrical quartz disc using epoxy resin, which is not stable in organic solvents and can be easily swollen or dissolved. The preparation of substrates more stable under severe conditions, such as in organic solvents, is necessary for extending application of the measurement. In this study, we report an easy method for preparing stable silica layers of ca. 2 μm in thickness deposited on gold layers (41 nm)/silica discs by sputtering, then annealed to enhance the stability. The obtained silica layers were stable and showed no swelling in organic solvents such as ethanol and toluene.

  5. Comparison of techniques for pre-concentrating radium from seawater

    International Nuclear Information System (INIS)

    Bourquin, M.; Van Beek, P.; Souhaut, M.; Jeandel, C.; Reyss, J.L.; Charette, M.A.

    2008-01-01

    In the framework of the KEOPS project (Kerguelen: compared study of the Ocean and the Plateau in Surface water), we aimed to provide information on the water mass pathways and vertical mixing on the Kerguelen Plateau, Southern Ocean, based on 228 Ra profiles. Because 228 Ra activities are extremely low in this area (∼ 0.1 dpm/100 kg or ∼ 2.10 -18 g kg -1 ), the filtration of large volumes of seawater was required in order to be able to detect it with minimal uncertainty. This challenging study was an opportunity for us to test and compare methods aimed at removing efficiently radium isotopes from seawater. We used Mn-fiber that retains radium and that allows the measurement of all four radium isotopes ( 226 Ra, 228 Ra, 223 Ra, 224 Ra). First, we used Niskin bottles or the ship's seawater intake to collect large volumes of seawater that were passed onto Mn-fiber in the laboratory. Second, we filled cartridges with Mn-fiber that we placed in tandem on in situ pumps. Finally, we fixed nylon nets filled with Mn-fiber on the frame of in situ pumps to allow the passive filtration of seawater during the pump deployment. Yields of radium fixation on the cartridges filled with Mn-fiber and placed on in situ pumps are ca. 30% when combining the two cartridges. Because large volumes of seawater can be filtered with these pumps, this yields to effective volumes of 177-280 kg (that is, higher than that recovered from fourteen 12-1 Niskin bottles). Finally, the effective volume of seawater that passed through Mn-fiber placed in nylon nets and deployed during 4 h ranged between 125 and 364 kg. Consequently, the two techniques that separate Ra isotopes in situ are good alternatives for pre-concentrating radium from seawater. They can save ship-time by avoiding repeated CTD casts to obtain the large volumes of seawater. This is especially true when in situ pumps are deployed to collect suspended particles. However, both methods only provide 228 Ra/ 226 Ra ratios. The

  6. [Measurements of surface ocean carbon dioxide partial pressure during WOCE]. Summary of research progress

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    This paper discusses the research progress of the second year of research under ``Measurement of Surface Ocean Carbon Dioxide Partial Pressure During WOCE`` and proposes to continue measurements of underway pCO{sub 2}. During most of the first year of this grant, our efforts to measure pCO{sub 2} on WOCE WHP legs were frustrated by ship problems. The R/V Knorr, which was originally scheduled to carry out the first work on WHP lines P19 and P16 in the southeastem Pacific during the 1990-91 austral summer, was delayed in the shipyard during her mid-life refit for more than a year. In the interim, the smaller R/V Thomas Washington, was pressed into service to carry out lower-latitude portions of WHP lines P16 and P17 during mid-1991 (TUNES Expedition). We installed and operated our underway chromatographic system on this expedition, even though space and manpower on this smaller vessel were limited and no one from our group would be aboard any of the 3 WHP expedition legs. The results for carbon dioxide and nitrous oxide are shown. A map of the cruise track is shown for each leg, marked with cumulative distance. Following each track is a figure showing the carbon dioxide and nitrous oxide results as a function of distance along this track. The results are plotted as dry-gas mole fractions (in ppm and ppb, respectively) in air and in gas equilibrated with surface seawater at a total pressure equal to the barometric pressure. The air data are plotted as a 10-point running mean, and appear as a roughly horizontal line. The seawater data are plotted as individual points, using a 5-point Gaussian smoother. Equal values Of xCO{sub 2} in air and surface seawater indicate air-sea equilibrium.

  7. Spatial distribution, ecological and health risk assessment of heavy metals in marine surface sediments and coastal seawaters of fringing coral reefs of the Persian Gulf, Iran.

    Science.gov (United States)

    Ranjbar Jafarabadi, Ali; Riyahi Bakhtiyari, Alireza; Shadmehri Toosi, Amirhossein; Jadot, Catherine

    2017-10-01

    Concentrations of 13 heavy metals (Al, Fe, Mn, Zn, Cu, Cr, Co, Ni, V, As, Cd, Hg, Pb) in 360 reef surface sediments (0-5 cm) and coastal seawater samples from ten coral Islands in the Persian Gulf were analyzed to determine their spatial distribution and potential ecological risks. Different sediment quality indices were applied to assess the surface sediment quality. The mean concentrations of metals in studied sediments followed the order: Al > Fe > Ni > V > Mn > Zn > Cu > Cr > Co > As > Cd > Pb > As. Average Cd and Hg exceeded coastal background levels at most sampling sites. With the exception of As, concentrations of heavy metals decreased progressively from the west to the east of the Persian Gulf. Based on the Enrichment Factor (EF) and Potential Ecological Risk Index (RI), concentrations of V, Ni, Hg and Cd indicated moderate contamination and is of some concern. The mean values of heavy metals Toxic Units (TUs) were calculated in the following order: Hg (0.75)> Cr (0.41)> Cd (0.27)> As (0.23)> Cu (0.12)> Zn (0.05)> Pb (0.009). Furthermore, the mean contributing ratios of six heavy metals to Toxic Risk Index (TRI) values were 79% for Hg, 11.48% for Cd, 6.16% for Cr, 3.27% for Cu, 0.07% for Zn and 0.01% for Pb. Calculated values of potential ecological risk factor, revealed that the risk of the heavy metals followed the order Cd > Pb > Ni > Cr > V > Cu > Zn. The results reflected that the level of heavy metals, especially Hg and Cd, are on rise due to emerging oil exploration, industrial development, and oil refineries along the entire Gulf. Fe, Mn, Cu, Zn, V and Ni concentrations in seawater were significantly higher (p heavy metals in the sampling sites. A health risk assessment using the hazard quotient index (HQ) recommended by the USEPA suggests that there is no adverse health effect through dermal exposure, and there is no carcinogenic and non-carcinogenic harm to human health. Copyright © 2017 Elsevier Ltd. All

  8. Neodymium isotopic variations in seawater

    Science.gov (United States)

    Piepgras, D. J.; Wasserburg, G. J.

    1980-01-01

    Direct measurement of the isotopic composition of Nd in the Atlantic agree with the Nd content in ferromanganese sediments and differ from the observed amounts in the Pacific samples. These data indicate the existence of distinctive differences in the isotopic composition of Nd in the waters of major oceans; the average values determined from seawater and ferromanganese sediments are considerably lower than in sources with oceanic mantle affinities showing that the REE in the oceans is dominated by continental sources. The Nd isotopic variations in seawater are applied to relate the residence time of Nd and mixing rates between the oceans.

  9. Perchlorate in seawater

    International Nuclear Information System (INIS)

    Martinelango, P. Kalyani; Tian Kang; Dasgupta, Purnendu K.

    2006-01-01

    There has been no reliable published data on the presence of perchlorate in seawater. Seaweeds are among the most important plant life in the ocean and are good sources of iodine and have been widely used as food and nutritional supplement. Perchlorate is known to inhibit the transport of iodide by the sodium iodide symporter (NIS), present e.g., in the thyroid and mammary glands. With perchlorate being increasingly detected in drinking water, milk and various other foods, increasing the iodide intake through inexpensive natural supplements may be an attractive solution for maintaining iodine assimilation. We report here measurable concentrations of perchlorate in several samples of seawater (detectable in about half the samples analyzed). We also report the iodide and perchlorate concentrations of 11 different species of seaweed and the corresponding bioconcentration factors (BCF) for perchlorate and iodide, relative to the seawater from which they were harvested. All seaweed samples came from the same region, off the coast of Northeastern Maine. Concentrations of iodide and perchlorate in four seawater samples collected from the region near harvest time were 30 ± 11 and 0.16 ± 0.084 μg l -1 , respectively. Concentrations of both iodide and perchlorate varied over a wide range for different seaweed species; iodide ranging from 16 to 3134 mg kg -1 and perchlorate from 0.077 to 3.2 mg kg -1 . The Laminaria species had the highest iodide concentration; Laminaria digitata is the seaweed species most commonly used in the kelp tablets sold in health food stores. Our sample of L. digitata contained 3134 ± 15 mg iodide/kg dry weight. The BCF varied widely for different species, with Laminaria species concentrating iodide preferentially over perchlorate. The iodide BCF (BCF i ) to perchlorate BCF (BCF p ) quotient ranged from 0.66 to 53; L. digitata and L. saccarina having a BCF i /BCF p value of 45 and 53, respectively, far greater than a simple anion exchange process

  10. Adsorption and corrosion-inhibiting effect of 2-(2-{l_brace}[2-(4-Pyridylcarbonyl)hydrazono]methyl{r_brace}phenoxy)acetic acid on mild steel surface in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Liu Baoyu, E-mail: liubaoyu084@163.com [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong 510640 (China); Xi Hongxia, E-mail: cehxxi@scut.edu.cn [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong 510640 (China); Li Zhong; Xia Qibin [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, Guangdong 510640 (China)

    2012-06-15

    The corrosion inhibition property of a Hydrazone derivative, namely 2-(2-{l_brace}[2-(4-Pyridylcabonyl)hydrazono]methyl{r_brace}phenoxy)acetic acid (PMA) for mild steel surface corrosion in synthetic seawater medium was analyzed by weight loss, electrochemical techniques (potentiodynamic polarization and electrochemical impedance), the experimental results suggest that PMA is a good corrosion inhibitor and the inhibition efficiency increased with the increase of PMA concentration, while the adsorption followed the Langmuir isotherm. X-ray photoelectron spectroscopy, scanning electron microscopy, theoretical calculation of electronic density, molecular electrostatic potential and molecular dynamics were carried out to establish mechanism of corrosion inhibition for mild steel with PMA in synthetic seawater medium. The inhibition action of the compound was assumed to occur via adsorption on the steel surface through the active centres in the molecule. The results indicated that the corrosion inhibition is due to the formation of a chemisorbed film on the steel surface.

  11. Seawater transport during coral biomineralization

    Science.gov (United States)

    Gagnon, Alexander C.; Adkins, Jess F.; Erez, Jonathan

    2012-05-01

    Cation transport during skeletal growth is a key process controlling metal/calcium (Me/Ca) paleoproxy behavior in coral. To characterize this transport, cultured corals were transferred into seawater enriched in the rare earth element Tb3 + as well as stable isotopes of calcium, strontium, and barium. Subsequent NanoSIMS ion images of each coral skeleton were used to follow uptake dynamics. These images show a continuous region corresponding to new growth that is homogeneously enriched in each tracer. Isotope ratio profiles across the new growth boundary transition rapidly from natural abundance ratios to a ratio matching the enriched culture solution. The location of this transition is the same for each element, within analytical resolution. The synchronous incorporation of all these cations, including the dissimilar ion terbium, which has no known biological function in coral, suggests that: (1) there is cation exchange between seawater and the calcifying fluid, and (2) these elements are influenced by similar transport mechanisms consistent with direct and rapid seawater transport to the site of calcification. Measured using isotope ratio profiles, seawater transport rates differ from place to place on the growing coral skeleton, with calcifying fluid turnover times from 30 min to 5.7 h. Despite these differences, all the elements measured in this study show the same transport dynamics at each location. Using an analytical geochemical model of biomineralization that includes direct seawater transport we constrain the role of active calcium pumping during calcification and we show that the balance between seawater transport and precipitation can explain observed Me/Ca variability in deep-sea coral.

  12. Measurement of Gas-Surface Accommodation

    Science.gov (United States)

    Trott, W. M.; Rader, D. J.; Castañeda, J. N.; Torczynski, J. R.; Gallis, M. A.

    2008-12-01

    Thermal accommodation coefficients have been determined for a variety of gas-surface combinations using an experimental apparatus developed to measure both the pressure dependence of the conductive heat flux and the variation of gas density between parallel plates separated by a gas-filled gap. Effects of gas composition, surface roughness and surface contamination have been examined with this system, and the behavior of gas mixtures has also been explored. Results are discussed in comparison with previous parallel-plate experimental studies as well as numerical simulations.

  13. Comprehensive and comparative ecotoxicological and human risk assessment of polycyclic aromatic hydrocarbons (PAHs) in reef surface sediments and coastal seawaters of Iranian Coral Islands, Persian Gulf.

    Science.gov (United States)

    Ranjbar Jafarabadi, Ali; Riyahi Bakhtiari, Alireza; Shadmehri Toosi, Amirhossein

    2017-11-01

    The concentration and spatial distribution along with ecotoxicological risk of 30 polycyclic aromatic hydrocarbons were investigated in the reef surface sediments (RSSs) and coastal seawater (CSW) of ten coral Islands from the Persian Gulf, Iran, in January 2015. For all sampling sites, assessment of ecological risk was undertaken using several approaches. Mean concentration of ∑30PAHs varied between 70 and 884ngL -l with an overall mean value of 464ngL -l in the CSW, while the RSS ranged from 274 to 1098ngg -1 dw with a total average of 619ngg -1 dw. The results showed a gradient in PAH concentration and toxicity estimates from the northern Hormoz site increasing to the eastern Kharg site. Most of the toxicity estimates were in the moderate range or less than risk values for damage to the marine environment. The calculated Dermal Hazard Quotient (HQs), the sum of HQs (HI) and other cancer risk values of most compounds were less than safety values at most sites. It means that the possibility of negative effects of PAHs via dermal absorption from sediments for children and adults is low. Some sampling sites studied have already been impacted with hazardous pollutants for an extended period of time and evidence from this investigation demonstrates that mixtures of PAHs may be carcinogenic to humans, especially in the western part of the Gulf. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Interpreting the probe-surface interaction of surface measuring instruments, or what is a surface?

    Science.gov (United States)

    Leach, Richard; Weckenmann, Albert; Coupland, Jeremy; Hartmann, Wito

    2014-09-01

    When using dimensional measuring instruments it is assumed that there is a property of the object, which we call surface, that is present before during and after the measurement, i.e. the surface is a fundamental property of an object that can, by appropriate means, be used to measure geometry. This paper will attempt to show that the fundamental property ‘surface’ does not exist in any simple form and that all the information we can have about a surface is the measurement data, which will include measurement uncertainty. Measurement data, or what will be referred to as the measured surface, is all that really exists. In this paper the basic physical differences between mechanically, electromagnetically and electrically measured surfaces are highlighted and discussed and accompanied by measurement results on a roughness artefact.

  15. Interpreting the probe-surface interaction of surface measuring instruments, or what is a surface?

    International Nuclear Information System (INIS)

    Leach, Richard; Weckenmann, Albert; Hartmann, Wito; Coupland, Jeremy

    2014-01-01

    When using dimensional measuring instruments it is assumed that there is a property of the object, which we call surface, that is present before during and after the measurement, i.e. the surface is a fundamental property of an object that can, by appropriate means, be used to measure geometry. This paper will attempt to show that the fundamental property ‘surface’ does not exist in any simple form and that all the information we can have about a surface is the measurement data, which will include measurement uncertainty. Measurement data, or what will be referred to as the measured surface, is all that really exists. In this paper the basic physical differences between mechanically, electromagnetically and electrically measured surfaces are highlighted and discussed and accompanied by measurement results on a roughness artefact. (paper)

  16. Method for estimating admixture content in seawater using operative spectrophotometry

    Science.gov (United States)

    Rostovtseva, V. V.; Konovalov, B. V.; Goncharenko, I. V.; Khlebnikov, D. V.

    2017-07-01

    The paper discusses spectra of the radiance coefficient of the sea surface measured in the open ocean and in coastal waters, and different kinds of these spectra corresponding to the water types are revealed. The focus is the method of measuring the radiance coefficient from a moving ship with a hyperspectral spectrophotometer. The results of studying a water area of Russia's Black Sea coast at river mouths are presented. A new calibration method that can process measurement results taking into account the impact of cloudiness and wind has been proposed and tested. The concentrations of the main admixtures in natural seawater in the studied water area are estimated according to the obtained spectra; these estimates are compared to the results of direct analysis of water samples. It has been shown that the method of remote measurement of the sea radiance coefficient from on board a ship makes it possible to obtain operative maps of the spatial distribution of the main seawater admixtures.

  17. Surface resistivity measurement of plasma treated polymers

    International Nuclear Information System (INIS)

    Simon, D.; Pigram, P.J.; Liesegang, J.

    2000-01-01

    Full text: Resistivity of insulators is an important property of materials used within the integrated circuit and packaging industries. The measurement of electrical resistivity of insulator materials in the surface region in this work is interpreted through observations of surface charge decay. A self-field driven and diffusion charge transport theory is used to model the process and resistivity values obtained computationally. Data for the charge decay of surface charged samples are collected by suspending them inside a coaxial cylinder connected to an electrometer. Samples used have been low density polyethylene LDPE sheet, both pristine and surface treated. Some samples have been treated by air plasma at low vacuum pressures for different periods of time; others have been washed in ethyl acetate and then plasma treated before the resistivity measurement. The sets of resistivity measurements form the various treatments are compared below. X-ray photoelectron spectroscopy (XPS) has also been used to investigate and account for the observed variations in surface resistivity

  18. In situ chemisorption of radiocesium from seawater

    International Nuclear Information System (INIS)

    Mann, D.R.; Casso, S.A.

    1984-01-01

    A novel approach to in situ extraction of Cs radionuclides from seawater is described which offers many advantages over previous methods. Cesium (stable and radioactive) is partially stripped from seawater as it passes in series through a tandem cartridge consisting of twin beds of ion exchange resin impregnated with cupric ferrocyanide. It is demonstrated that, when seawater passes through this cartridge at a constant flow-rate, collection efficiencies of each bed are the same, allowing the calculation of the seawater Cs nuclide concentration. The cartridge is made of inexpensive, readily available, PVC pipe fittings and is easily deployed under various field conditions. Procedures are described for resin preparation and desorption and radiochemical purification of the collected Cs. Thousands of liters of seawater can be stripped of Cs in this way, permitting substantial improvement in the sensitivity of measurement of 134 Cs and 137 Cs. (Auth.)

  19. Development of radioactive seawater monitors, 1

    International Nuclear Information System (INIS)

    Fukushima, Masanori

    1989-01-01

    Applicability of some adsorptive materials to monitoring of radioactive seawater is generalized. Studied techniques that allow utilization of adsorptive materials in monitoring radioactive seawater are the substitute methods using sampled seawater or indicator plants such as gulfweed and the method using adsorptive materials for continuous monitoring of underwater radioactivity, the method using them for field measurement of under water radioactivity from a boat, and the method using an adsorptive material moored underwater for integration monitoring of underwater radioactivity. Selected adsorptive materials that were judged suitable for monitoring radioactive seawater is the one composed of some kind of adsorptive compound (manganese dioxide or ferrocyan cobalt potassium) fixed to crylic cellulose. This adsorptive material permits selective scavenging radioactive Cs, Mn, Co, Zn, Ce, Fe, Ru, Ra Th, Pu and Am from seawater. (aurhor)

  20. Microbial activities and dissolved organic matter dynamics in oil-contaminated surface seawater from the Deepwater Horizon oil spill site.

    Directory of Open Access Journals (Sweden)

    Kai Ziervogel

    Full Text Available The Deepwater Horizon oil spill triggered a complex cascade of microbial responses that reshaped the dynamics of heterotrophic carbon degradation and the turnover of dissolved organic carbon (DOC in oil contaminated waters. Our results from 21-day laboratory incubations in rotating glass bottles (roller bottles demonstrate that microbial dynamics and carbon flux in oil-contaminated surface water sampled near the spill site two weeks after the onset of the blowout were greatly affected by activities of microbes associated with macroscopic oil aggregates. Roller bottles with oil-amended water showed rapid formation of oil aggregates that were similar in size and appearance compared to oil aggregates observed in surface waters near the spill site. Oil aggregates that formed in roller bottles were densely colonized by heterotrophic bacteria, exhibiting high rates of enzymatic activity (lipase hydrolysis indicative of oil degradation. Ambient waters surrounding aggregates also showed enhanced microbial activities not directly associated with primary oil-degradation (β-glucosidase; peptidase, as well as a twofold increase in DOC. Concurrent changes in fluorescence properties of colored dissolved organic matter (CDOM suggest an increase in oil-derived, aromatic hydrocarbons in the DOC pool. Thus our data indicate that oil aggregates mediate, by two distinct mechanisms, the transfer of hydrocarbons to the deep sea: a microbially-derived flux of oil-derived DOC from sinking oil aggregates into the ambient water column, and rapid sedimentation of the oil aggregates themselves, serving as vehicles for oily particulate matter as well as oil aggregate-associated microbial communities.

  1. Surface Tension Measurements with a Smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-01-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept…

  2. Surface charge measurement using an electrostatic probe

    DEFF Research Database (Denmark)

    Crichton, George C; McAllister, Iain Wilson

    1998-01-01

    During the 1960s, the first measurements of charge on dielectric surfaces using simple electrostatic probes were reported. However it is only within the last 10 years that a proper understanding of the probe response has been developed. This situation arose as a consequence of the earlier studies...

  3. Optical measurement of surface roughness in manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Brodmann, R.

    1984-11-01

    The measuring system described here is based on the light-scattering method, and was developed by Optische Werke G. Rodenstock, Munich. It is especially useful for rapid non-contact monitoring of surface roughness in production-related areas. This paper outlines the differences between this system and the common stylus instrument, including descriptions of some applications in industry.

  4. Surface dose extrapolation measurements with radiographic film

    International Nuclear Information System (INIS)

    Butson, Martin J; Cheung Tsang; Yu, Peter K N; Currie, Michael

    2004-01-01

    Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields. An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate two-dimensional map of surface dose if required. Results have shown that the surface percentage dose can be estimated within ±3% of parallel plate ionization chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10 cm, 20 cm and 30 cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. The corresponding parallel plate ionization chamber measurements are 16%, 27% and 37%, respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size. (note)

  5. Novel surface measurement system reading cost savings

    Energy Technology Data Exchange (ETDEWEB)

    Sword, M.

    1996-05-01

    A new state-of-the-art data acquisition system for the oil and natural gas industries is being marketed by OPSCO`92 Industries Ltd. The unit is portable, it measures surface data which is calibrated to bottom-hole conditions and designed to measure temperature and pressure information without the necessity of sending testing equipment downhole. The Surface Data System (SDS) uses silicon-crystal technology, is mounted in a suitcase size carrying case, and runs off a 12-volt battery enclosure which can be backed up by a small solar panel. The first generation system can handle 16 different channels of information input on a laptop computer. Pressure, pressure differential, temperature, frequency and pulse signals for flow meter measurements are handled by standard sensors. Areas of application include build-up and fall-off tests, pipeline evaluation, pre-frac tests, underbalanced drilling and gas well evaluation. 1 fig., 1 photo.

  6. Minimizing Uncertainty in Cryogenic Surface Figure Measurement

    Science.gov (United States)

    Blake, Peter; Mink, Ronald G.; Chambers, John; Robinson, F. David; Content, David; Davila, Pamela

    2005-01-01

    A new facility at the Goddard Space Flight Center is designed to measure with unusual accuracy the surface figure of mirrors at cryogenic temperatures down to 12 K. The facility is currently configured for spherical mirrors with a radius of curvature (ROC) of 600 mm, and apertures of about 150 mm or less. The goals of the current experiment were to 1) Obtain the best possible estimate of test mirror surface figure, S(x,y) at 87 K and 20 K; 2) Obtain the best estimate of the cryo-change, Delta (x,y): the change in surface figure between room temperature and the two cryo-temperatures; and 3) Determine the uncertainty of these measurements, using the definitions and guidelines of the ISO Guide to the Expression of Uncertainty in Measurement. A silicon mirror was tested, and the cry-change from room temperature to 20K was found to be 3.7 nm rms, with a standard uncertainty of 0.23 nm in the rms statistic. Both the cryo-change figure and the uncertainty are among the lowest such figures yet published. This report describes the facilities, experimental methods, and uncertainty analysis of the measurements.

  7. Identification of Corrosion Products Due to Seawater and Fresh Water

    Science.gov (United States)

    Gismelseed, A.; Elzain, M.; Yousif, A.; Al Rawas, A.; Al-Omari, I. A.; Widatallah, H.; Rais, A.

    2004-12-01

    Mössbauer and X-ray diffraction (XRD) measurements were performed on corrosion products extracted from the inner surface of two different metal tubes used in a desalination plant in Oman. One of the tubes corroded due to the seawater while the second was corroded due to fresh water. The corrosion products thus resulted due to seawater were scrapped off in to two layers, the easily removable rust from the top is termed outer surface corrosion product and the strongly adhered rust as internal corrosion product. The Mössbauer spectra together with the XRD pattern of the outer surface showed the presence of magnetite (Fe3O4), akaganeite (β-FeOOH), lepidocrocite (γ-FeOOH), goethite (α-FeOOH) and hematite (Fe2O3). The inner surface however showed the presence of akaganite, goethite, and magnetite. On the other hand, the corrosion products due to the fresh water showed only the presence of goethite and magnetite. The mechanism of the corrosion process will be discussed based on the significant differences between the formation of the iron components of the corrosion products due to seawater and the fresh water.

  8. Seawater predesalination with electrodialysis

    NARCIS (Netherlands)

    Galama, A.H.; Saakes, M.; Bruning, H.; Rijnaarts, H.H.M.; Post, J.W.

    2014-01-01

    The suitability of ED for seawater desalination was investigated and we quantified the energy losses that play a role in electrodialysis. The combination of electrodialysis (ED) and brackish water reverse osmosis (BWRO) is presented as an alternative desalination strategy for seawater reverse

  9. Impact of seawater [Ca

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; Thoms, S.; Nehrke, G.; Reichart, G.J.; de Nooijer, L.J.; Bijma, J.

    2015-01-01

    Mg / Ca ratios in foraminiferal tests are routinely used as paleotemperature proxies, but on long timescales, they also hold the potential to reconstruct past seawater Mg / Ca. The impact of both temperature and seawater Mg / Ca on Mg incorporation in Foraminifera has been quantified by a number of

  10. Nature/culture/seawater.

    Science.gov (United States)

    Helmreich, Stefan

    2011-01-01

    Seawater has occupied an ambiguous place in anthropological categories of "nature" and "culture." Seawater as nature appears as potentiality of form and uncontainable flux; it moves faster than culture - with culture frequently figured through land-based metaphors - even as culture seeks to channel water's (nature's) flow. Seawater as culture manifests as a medium of pleasure, sustenance, travel, disaster. I argue that, although seawater's qualities in early anthropology were portrayed impressionistically, today technical, scientific descriptions of water's form prevail. For example, processes of globalization - which may also be called "oceanization" - are often described as "currents," "flows," and "circulations." Examining sea-set ethnography, maritime anthropologies, and contemporary social theory, I propose that seawater has operated as a “theory machine” for generating insights about human cultural organization. I develop this argument with ethnography from the Sargasso Sea and in the Sea Islands. I conclude with a critique of appeals to water's form in social theory.

  11. Radioimmunoassay to quantitatively measure cell surface immunoglobulins

    International Nuclear Information System (INIS)

    Krishman, E.C.; Jewell, W.R.

    1975-01-01

    A radioimmunoassay techniques developed to quantitatively measure the presence of immunoglobulins on the surface of cells, is described. The amount of immunoglobulins found on different tumor cells varied from 200 to 1140 ng/10 6 cells. Determination of immunoglobulins on the peripheral lymphocytes obtained from different cancer patients varied between 340 to 1040 ng/10 6 cells. Cultured tumor cells, on the other hand, were found to contain negligible quantities of human IgG [pt

  12. Description of measurement techniques for surface contaminations

    International Nuclear Information System (INIS)

    Bourrez, E.

    2001-01-01

    The needs of evaluation of the surface contamination are numerous in the processes of production and management of radioactive waste. The market of radiation protection materials proposes a lot of devices answering to the almost all these needs. These device have however their conditions and particular limits for use. To realize correct measurements it is use the device, the technique and the methods adapted to the need, by taking into account the optimization of economical aspect. (N.C.)

  13. Acoustic Impedance Measurement for Underground Surfaces.

    Science.gov (United States)

    Cockcroft, Paul William

    Available from UMI in association with The British Library. Requires signed TDF. This thesis investigates the measurement of acoustic impedance for surfaces likely to be found in underground coal mines. By introducing the concepts of industrial noise, the effects of noise on the ear and relevant legislation the need for the protection of workers can be appreciated. Representative acoustic impedance values are vital as input for existing computer models that predict sound levels in various underground environments. These enable the mining engineer to predict the noise level at any point within a mine in the vicinity of noisy machinery. The concepts of acoustic intensity and acoustic impedance are investigated and different acoustic impedance measurement techniques are detailed. The possible use of either an impedance tube or an intensity meter for these kinds of measurements are suggested. The problems with acoustic intensity and acoustic impedance measurements are discussed with reference to the restraints that an underground environment imposes on any measurement technique. The impedance tube method for work in an acoustics laboratory is shown and the theory explained, accompanied by a few representative results. The use of a Metravib intensity meter in a soundproof chamber to gain impedance values is explained in detail. The accompanying software for the analysis of the two measured pressure signals is shown as well as the actual results for a variety of test surfaces. The use of a Nagra IV-SJ tape recorder is investigated to determine the effect of recording on the measurement and subsequent analysis of the input signals, particularly with reference to the phase difference introduced between the two simultaneous pressure signals. The subsequent use of a Norwegian Electronic intensity meter, including a proposal for underground work, is shown along with results for tests completed with this piece of equipment. Finally, recommendations are made on how to link up

  14. Ultra-trace plutonium determination in small volume seawater by sector field inductively coupled plasma mass spectrometry with application to Fukushima seawater samples.

    Science.gov (United States)

    Bu, Wenting; Zheng, Jian; Guo, Qiuju; Aono, Tatsuo; Tagami, Keiko; Uchida, Shigeo; Tazoe, Hirofumi; Yamada, Masatoshi

    2014-04-11

    Long-term monitoring of Pu isotopes in seawater is required for assessing Pu contamination in the marine environment from the Fukushima Dai-ichi Nuclear Power Plant accident. In this study, we established an accurate and precise analytical method based on anion-exchange chromatography and SF-ICP-MS. This method was able to determine Pu isotopes in seawater samples with small volumes (20-60L). The U decontamination factor was 3×10(7)-1×10(8), which provided sufficient removal of interfering U from the seawater samples. The estimated limits of detection for (239)Pu and (240)Pu were 0.11fgmL(-1) and 0.08fgmL(-1), respectively, which corresponded to 0.01mBqm(-3) for (239)Pu and 0.03mBqm(-3) for (240)Pu when a 20L volume of seawater was measured. We achieved good precision (2.9%) and accuracy (0.8%) for measurement of the (240)Pu/(239)Pu atom ratio in the standard Pu solution with a (239)Pu concentration of 11fgmL(-1) and (240)Pu concentration of 2.7fgmL(-1). Seawater reference materials were used for the method validation and both the (239+240)Pu activities and (240)Pu/(239)Pu atom ratios agreed well with the expected values. Surface and bottom seawater samples collected off Fukushima in the western North Pacific since March 2011 were analyzed. Our results suggested that there was no significant variation of the Pu distribution in seawater in the investigated areas compared to the distribution before the accident. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Automated solid-phase extraction for trace-metal analysis of seawater: sample preparation for total-reflection X-ray fluorescence measurements

    Science.gov (United States)

    Gerwinski, Wolfgang; Schmidt, Diether

    1998-08-01

    Solid-phase chromatography on silica gel columns can be used as a sample preparation technique for seawater, followed by total-reflection X-ray fluorescence analysis (TXRF). An automated extraction system (Zymark AutoTrace SPE Workstation) was studied for the analysis of blank solutions, seawater samples and certified reference materials. After replacing some stainless steel parts in the system, adequate blanks could be obtained to allow the analysis of seawater samples. Replicate analyses yielded low standard deviations and good recoveries for certified reference materials. Using a six-channel model and user-defined software, the time needed for a complete analytical run was about 100 min.

  16. Measuring the Valence of Nanocrystal Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Owen, Jonathan Scharle [Columbia Univ., New York, NY (United States)

    2016-11-30

    The goal of this project is to understand and control the interplay between nanocrystal stoichiometry, surface ligand binding and exchange, and the optoelectronic properties of semiconductor nanocrystals in solution and in thin solid films. We pursued three research directions with this goal in mind: 1) We characterized nanocrystal stoichiometry and its influence on the binding of L-type and X-type ligands, including the thermodynamics of binding and the kinetics of ligand exchange. 2) We developed a quantitative understanding of the relationship between surface ligand passivation and photoluminescence quantum yield. 3) We developed methods to replace the organic ligands on the nanocrystal with halide ligands and controllably deposit these nanocrystals into thin films, where electrical measurements were used to investigate the electrical transport and internanocrystal electronic coupling.

  17. Measuring the radium quartet ({sup 228}Ra, {sup 226}Ra, {sup 224}Ra, {sup 223}Ra) in seawater samples using gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Beek, P. van, E-mail: vanbeek@legos.obs-mip.f [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Souhaut, M. [LEGOS, Laboratoire d' Etudes en Geophysique et Oceanographie Spatiales (CNRS/CNES/IRD/UPS), Observatoire Midi Pyrenees, 14 Avenue Edouard Belin, 31400 Toulouse (France); Reyss, J.-L. [LSCE, Laboratoire des Sciences du Climat et de l' Environnement (CNRS/CEA/UVSQ), Avenue de la Terrasse, 91198 Gif-sur-Yvette (France)

    2010-07-15

    Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While {sup 228}Ra and {sup 226}Ra are usually measured using gamma spectrometry, short-lived Ra isotopes ({sup 224}Ra and {sup 223}Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report {sup 226}Ra, {sup 228}Ra, {sup 224}Ra, {sup 223}Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccares lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The {sup 223}Ra and {sup 224}Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the {sup 224}Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low {sup 223}Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes.

  18. High surface-area amidoxime-based polymer fibers co-grafted with various acid monomers yielding increased adsorption capacity for the extraction of uranium from seawater.

    Science.gov (United States)

    Oyola, Yatsandra; Dai, Sheng

    2016-06-07

    Uranium is dissolved in the ocean at a uniform concentration of 3.34 ppb, which translates to approximately 4-5 billion tons of uranium. The development of adsorbents that can extract uranium from seawater has been a long term goal, but the extremely dilute uranium concentration along with the competition of other metal salts (which are at higher concentrations) has hindered the development of an economical adsorption process. Several acid monomers were co-grafted with acrylonitrile (AN) to help increase the hydrophilicity of the adsorbent to improve access to the metal adsorption sites. Grafting various acid monomers on PE fibers was found to significantly affect the uranium adsorption in simulated seawater in the following order: acrylic acid (AA) seawater (more dilute uranium), the uranium adsorption capacity increased in the following order: MAA seawater results. Characterization of the adsorbents indicated that the increase in uranium adsorption capacity with each acid monomer was related to higher grafting of AN and therefore a higher conversion to amidoxime (AO).

  19. Evaluation of Arctic broadband surface radiation measurements

    Directory of Open Access Journals (Sweden)

    N. Matsui

    2012-02-01

    Full Text Available The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW and thermal infrared, or longwave (LW, radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse SW measurements. The difference between these two quantities (that theoretically should be zero is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

  20. Calibration of areal surface topography measuring instruments

    Science.gov (United States)

    Seewig, J.; Eifler, M.

    2017-06-01

    The ISO standards which are related to the calibration of areal surface topography measuring instruments are the ISO 25178-6xx series which defines the relevant metrological characteristics for the calibration of different measuring principles and the ISO 25178-7xx series which defines the actual calibration procedures. As the field of areal measurement is however not yet fully standardized, there are still open questions to be addressed which are subject to current research. Based on this, selected research results of the authors in this area are presented. This includes the design and fabrication of areal material measures. For this topic, two examples are presented with the direct laser writing of a stepless material measure for the calibration of the height axis which is based on the Abbott- Curve and the manufacturing of a Siemens star for the determination of the lateral resolution limit. Based on these results, as well a new definition for the resolution criterion, the small scale fidelity, which is still under discussion, is presented. Additionally, a software solution for automated calibration procedures is outlined.

  1. Seasonal slope surface deformation measured with TLS

    International Nuclear Information System (INIS)

    Fan, L; Smethurst, J; Powrie, W; Sellaiya, A

    2014-01-01

    In temperate European climates, soil water removal due to vegetation transpiration peaks in summer and soil rewetting from higher levels of precipitation occurs in winter. In clays of high plasticity, the seasonal cycles of drying and wetting cause the soil to experience a volumetric change, resulting in seasonal shrinking and swelling. For a clay slope exhibiting volume change, such behaviour can lead to excessive deformation and could contribute to strain-softening and progressive slope failure. This can in turn cause traffic disruption and loss of life if roads and railways are founded on or surrounded by such slopes. This paper discusses the driving forces of seasonal surface movement, in particular the role of vegetation, and presents the use of Terrestrial Laser Scanning (TLS) to measure the surface movement of a lightly vegetated London Clay slope near Newbury, UK. Two TLS scans were carried out in early and late summer respectively, representing relative wet and dry conditions of the slope. Continuous field measurements of soil water content in upper layers of the slope were obtained from TDR ThetaProbes already installed at the site. The water content data are used to support the results obtained from TLS by indicating the likely volumetric change in the soil due to loss of water

  2. Monitoring of uranium isotopes in seaweeds and seawater

    International Nuclear Information System (INIS)

    Meena, Balram; Mehendarge, S.T.; Baburajan, A.; Rao, D.D.

    2012-01-01

    The paper deals with the concentration of uranium in seawater and different types of seaweed found along the coast line of Tarapur marine environment. The seaweeds are the trend indicators of heavy metals and radionuclides present in the aquatic environment. Seaweeds also serve as a food to the marine organisms and thus can enter the human being through food chain. The higher concentration of uranium in seafood may have radiological impact on human health. The Tarapur Atomic Power Station is adjoined to the sea and has a rocky surface area, which act as a good dwelling for the growth and survival of marine biota. In present study, separation and measurements were made to determine the uranium concentration in seaweed seawater at Tarapur coastal environment

  3. Sea Surface Temperatures (SST): Significance and Measurement

    Science.gov (United States)

    Singer, S. F.

    2006-05-01

    Oceans cover 71 percent of Earth's surface and control the global climate. Quoted global mean temperature values and trends, largely based on land thermometers, differ substantially -" mainly because of uncertainties about SST. The ongoing controversy about the relative importance of natural climate changes and Anthropogenic Global Warming (AGW) revolves mainly around disparities between temperature trends of the atmosphere and surface (in the tropics and SH, i.e. mostly SST). Accurate measurement of SST is difficult. Geographic coverage is poor and there are many different techniques, each with its own problems and uncertainties: Water temperatures from buckets and ship-engine inlets; fixed and floating buoys; air temperatures from shipboard and island stations; and remote sensing from satellites using IR and microwaves. As is evident, each technique refers to a different level below the air-water interface. Drifter buoys (at around 50 cm) measure temperatures in the euphotic layers that are generally warmer than the bulk mixed layer sampled by ships (typically around 10 m). The IR emission arises from a 10-micron-thick skin that interacts dynamically with the underlying "mixed layer." The microwave data depend also on emissivity and therefore on surface roughness and sea state. SST data derived from corals provide some support for instrumental data but are not conclusive. The majority of corals show a warming trend since 1979; others show cooling or are ambiguous. There are different ways of interpreting this result. Physical optics dictates that the downwelling IR radiation from atmospheric greenhouse gases is absorbed in the first instance within the skin. Only direct measurements can establish how much of this energy is shared with the bulk mixed layer (to which the usual SST values refer.). SST controls evaporation and therefore global precipitation. SST influences tropical cyclones and sea-level rise; but there is lively debate on those issues. Changes in

  4. Quadrotor helicopter for surface hydrological measurements

    Science.gov (United States)

    Pagano, C.; Tauro, F.; Porfiri, M.; Grimaldi, S.

    2013-12-01

    Surface hydrological measurements are typically performed through user-assisted and intrusive field methodologies which can be inadequate to monitor remote and extended areas. In this poster, we present the design and development of a quadrotor helicopter equipped with digital acquisition system and image calibration units for surface flow measurements. This custom-built aerial vehicle is engineered to be lightweight, low-cost, highly customizable, and stable to guarantee optimal image quality. Quadricopter stability guarantees minimal vibrations during image acquisition and, therefore, improved accuracy in flow velocity estimation through large scale particle image velocimetry algorithms or particle tracking procedures. Stability during the vehicle pitching and rolling is achieved by adopting large arm span and high-wing configurations. Further, the vehicle framework is composed of lightweight aluminum and durable carbon fiber for optimal resilience. The open source Ardupilot microcontroller is used for remote control of the quadricopter. The microcontroller includes an inertial measurement unit (IMU) equipped with accelerometers and gyroscopes for stable flight through feedback control. The vehicle is powered by a 3 cell (11.1V) 3000 mAh Lithium-polymer battery. Electronic equipment and wiring are hosted into the hollow arms and on several carbon fiber platforms in the waterproof fuselage. Four 35A high-torque motors are supported at the far end of each arm with 10 × 4.7 inch propellers. Energy dissipation during landing is accomplished by four pivoting legs that, through the use of shock absorbers, prevent the impact energy from affecting the frame thus causing significant damage. The data capturing system consists of a GoPro Hero3 camera and in-house built camera gimbal and shock absorber damping device. The camera gimbal, hosted below the vehicle fuselage, is engineered to maintain the orthogonality of the camera axis with respect to the water surface by

  5. Technical note: Examining ozone deposition over seawater

    Science.gov (United States)

    Sarwar, Golam; Kang, Daiwen; Foley, Kristen; Schwede, Donna; Gantt, Brett; Mathur, Rohit

    2016-09-01

    Surface layer resistance plays an important role in determining ozone deposition velocity over sea-water and can be influenced by chemical interactions at the air-water interface. Here, we examine the effect of chemical interactions of iodide, dimethylsulfide, dissolved organic carbon, and bromide in seawater on ozone deposition. We perform a series of simulations using the hemispheric Community Multiscale Air Quality model for summer months in the Northern Hemisphere. Our results suggest that each chemical interaction enhances the ozone deposition velocity and decreases the atmospheric ozone mixing ratio over seawater. Iodide enhances the median deposition velocity over seawater by 0.023 cm s-1, dissolved organic carbon by 0.021 cm s-1, dimethylsulfide by 0.002 cm s-1, and bromide by ∼0.0006 cm s-1. Consequently, iodide decreases the median atmospheric ozone mixing ratio over seawater by 0.7 ppb, dissolved organic carbon by 0.8 ppb, dimethylsulfide by 0.1 ppb, and bromide by 0.02 ppb. In a separate model simulation, we account for the effect of dissolved salts in seawater on the Henry's law constant for ozone and find that it reduces the median deposition velocity by 0.007 cm s-1 and increases surface ozone mixing ratio by 0.2 ppb. The combined effect of these processes increases the median ozone deposition velocity over seawater by 0.040 cm s-1, lowers the atmospheric ozone mixing ratio by 5%, and slightly improves model performance relative to observations.

  6. The Geologic History of Seawater

    Science.gov (United States)

    Holland, H. D.

    2003-12-01

    Aristotle proposed that the saltness of the sea was due to the effect of sunlight on water. Robert Boyle took strong exception to this view and - in the manner of the Royal Society - laid out a program of research in the opening paragraph of his Observations and Experiments about the Saltness of the Sea (1674) (Figure 1): (20K)Figure 1. Title page of Robert Boyle's Tracts consisting of Observations about the Saltness of the Sea and other essays (1674). The Cause of the Saltness of the Sea appears by Aristotle's Writings to have busied the Curiosity of Naturalists before his time; since which, his Authority, perhaps much more than his Reasons, did for divers Ages make the Schools and the generality of Naturalists of his Opinion, till towards the end of the last Century, and the beginning of ours, some Learned Men took the boldness to question the common Opinion; since when the Controversie has been kept on foot, and, for ought I know, will be so, as long as ‘tis argued on both sides but by Dialectical Arguments, which may be probable on both sides, but are not convincing on either. Wherefore I shall here briefly deliver some particulars about the Saltness of the Sea, obtained by my own trials, where I was able; and where I was not, by the best Relations I could procure, especially from Navigators.Boyle measured and compiled a considerable set of data for variations in the saltness of surface seawater. He also designed an improved piece of equipment for sampling seawater at depth, but the depths at which it was used were modest: 30 m with his own instrument, 80 m with another, similar sampler. However, the younger John Winthrop (1606-1676), an early member of the Royal Society, an important Governor of Connecticut, and a benefactor of Harvard College, was asked to collect seawater from the bottom of the Atlantic Ocean during his crossing from England to New England in the spring of 1663. The minutes of the Royal Society's meeting on July 20, 1663, give the

  7. Structure stability and corrosion inhibition of super-hydrophobic film on aluminum in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Yin Yansheng [Institute of Ocean Materials and Engineering, Shanghai Maritime University, Shanghai 200135 (China)], E-mail: yys2003ouc@163.com; Liu Tao; Chen Shougang; Liu Tong; Cheng Sha [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100 (China)

    2008-12-30

    A novel and stable super-hydrophobic film was prepared by myristic acid (CH{sub 3}(CH{sub 2}){sub 12}COOH, mya) chemically adsorbed onto the anodized aluminum surface. The static contact angle for seawater on the surface was measured to be 154 deg. As evidenced by molecular dynamics (MD) simulations and electrochemical impedance spectroscopy (EIS), the effect of ethanol solvent on the film stability was proved. The surface structure and composition were then characterized by means of scanning electron microscopy (SEM) with energy dispersive X-ray spectrum (EDS) and atomic force microscope (AFM). The electrochemical measurements showed that the super-hydrophobic surface significantly decreased the corrosion currents densities (i{sub corr}), corrosion rates and double layer capacitance (C{sub dl}), as simultaneously increased the values of polarization resistance (R{sub ct}) of aluminum in sterile seawater.

  8. Determining subnanomolar iron concentrations in oceanic seawater using a siderophore-modified film analyzed by infrared spectroscopy.

    Science.gov (United States)

    Roy, Eric G; Jiang, Cuihong; Wells, Mark L; Tripp, Carl

    2008-06-15

    Iron is a bioactive trace element in seawater that regulates photosynthetic carbon dioxide drawdown and export from surface waters by phytoplankton in upward of 40% of the world's oceans. While autonomous sensor arrays are beginning to provide high-resolution data on temporal and spatial scales for some key oceanographic parameters, current analytical methods for iron are not amenable to autonomous platforms because of the need for user involvement and wet chemistry-based approaches. As a result, very large gaps remain in our understanding of iron distribution and chemistry in seawater. Here we present a straightforward nanostructure-based method to measure dissolved iron in natural seawater. The device comprises an iron-specific chelating biomolecule, desferrioxamine B (DFB), covalently immobilized on a mesoporous silica film. Changes in infrared spectral signatures of the immobilized DFB upon Fe(III) complexation provide an accurate and precise measure of iron on the surface of a chip exposed to seawater. The current system has a detection limit of approximately 50 pM for a 1-L sample at pH 1.7 and was used to measure dissolved iron in subarctic Pacific waters without interference from other elements in seawater. This technology provides a major step toward obtaining accurate iron measurements on autonomous research platforms.

  9. Technical note: Examining ozone deposition over seawater

    Science.gov (United States)

    Surface layer resistance plays an important role in determining ozone deposition velocity over sea-water and can be influenced by chemical interactions at the air-water interface. Here, we examine the effect of chemical interactions of iodide, dimethylsulfide, dissolved organic c...

  10. Fiber-optic-based chemical sensors for in-situ measurement of metals and aromatic organic compounds in seawater and soil systems

    Science.gov (United States)

    Lieberman, Stephen H.; Inman, Scott; Theriault, Gregory A.; Cooper, Stafford S.; Malone, Philip G.; Shimizu, Yasuhiro; Lurk, Paul W.

    1990-08-01

    Use of UV-visibletransmitting optical fibers for real-time, remote, in situfluorescencemeasurementsof chemical constituents in environmental samples is described. In order to improve the capability of fluorescence techniques for resoMng complex mixtures we have deVelOped a fiber optic-based system that uses a pulsed nrogen laser to induce fluorescence and a time-gated linear photodiode array coupled to a spectrograph for measuring resutting emisalon spectra This permfts rapid extraction of both spectral information and temporal data (fluorescence decay times). The performance of the system for monftoring aromatic hydrocarbons directly in seawater over a bare-ended" fiber optic cable is discussed. Techniques for extending the Capability to determination of metals and other non-fluorescing compounds are presented. A system in which a fluorogenic indicator molecule for metal ions is constantly renewed at the sensing end of the fiber is described that (1)exhibits very fast response times (1 second) and (2)eliminates problems of reversibility common with immobilized indicators. Presently, the pulsed-laser/photodiode fiber optic system is being adapted to a truck-mounted cone penetrometer system for characterizing the distribution of chemical contaminants at hazardous waste sites. The system can push a 35.7 mm diameter rod up to 50 m into the sI at a rate of approximately 2 cm/sec. The penetrometer probe tip will be equipped with sapphire viewing windows that permft one fiber to screen for aromatic orgarc compounds and a fluorogeruc indicator release system that can be used with a second fiber for trace metal screening.

  11. Uranium extraction from seawater

    International Nuclear Information System (INIS)

    Koske, P.H.; Ohlrogge, K.; Denzinger, H.

    1982-01-01

    Besides basic considerations about the problem of Uranium extraction from seawater system studies on process engineering and marine technology approaches are presented. In addition the present and future developments in the Federal Republic of Germany are discussed in somewhat more detail. (orig.) [de

  12. [Measuring microhardness of laser exposed tooth surface].

    Science.gov (United States)

    Florin, R; Herrmann, C; Bernhardt, W

    1990-02-01

    In principle it is possible to homogenize the enamel surface by melting structural elements with the continuous wave CO2 laser. Using the precision instrument NEOPHOT 2 (Carl Zeiss JENA) the microhardness of extracted laserexposed premolares were tested so as to clarify the functional strain capasity and the mechanical characteristics of laserexposed regions of enamel surfaces. The proven higher hardness in the centre of the laserinduced fusing zones (in comparison with adjacent enamel) objectify an attainable refining of the enamel surface that probably causes an increase in the caries-preventive resistance.

  13. Surface texturing of crystalline silicon and effective area measurement

    Science.gov (United States)

    Sun, Tietun; Chen, Dong; Chui, Rongqiang

    2000-11-01

    In this paper, the surface area of solar cell is determined by the capacitance measurements of MOS structure. The texture etching technology can be controlled according to the change of silicon surface area, furthermore, the textured silicon surface and interface characteristic of solar cell can be studied by measuring the relationship of capacitance and voltage for MOS structure.

  14. High speed machined surface roughness measurement ...

    African Journals Online (AJOL)

    Surface roughness monitoring techniques using non-contact methods based on computer vision technology are becoming popular and cost effective. An evolvable hardware configuration using reconfigurable Xilinx Virtex FPGA xcv1000 architecture with capability to compensate for poor illumination environment is ...

  15. Rapid determination of radiostrontium in seawater samples

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Sherrod L.; Culligan, Brian K.; Utsey, Robin C.

    2013-03-12

    A new method for the determination of radiostrontium in seawater samples has been developed at the Savannah River National Laboratory (SRNL) that allows rapid preconcentration and separation of strontium and yttrium isotopes in seawater samples for measurement. The new SRNL method employs a novel and effective pre-concentration step that utilizes a blend of calcium phosphate with iron hydroxide to collect both strontium and yttrium rapidly from the seawater matrix with enhanced chemical yields. The pre-concentration steps, in combination with rapid Sr Resin and DGA Resin cartridge separation options using vacuum box technology, allow seawater samples up to 10 liters to be analyzed. The total 89Sr + 90Sr activity may be determined by gas flow proportional counting and recounted after ingrowth of 90Y to differentiate 89Sr from 90Sr. Gas flow proportional counting provides a lower method detection limit than liquid scintillation or Cerenkov counting and allows simultaneous counting of samples. Simultaneous counting allows for longer count times and lower method detection limits without handling very large aliquots of seawater. Seawater samples up to 6 liters may be analyzed using Sr Resin for 89Sr and 90Sr with a Minimum Detectable Activity (MDA) of 1-10 mBq/L, depending on count times. Seawater samples up to 10 liters may be analyzed for 90Sr using a DGA Resin method via collection and purification of 90Y only. If 89Sr and other fission products are present, then 91Y (beta energy 1.55 MeV, 58.5 day half-life) is also likely to be present. 91Y interferes with attempts to collect 90Y directly from the seawater sample without initial purification of Sr isotopes first and 90Y ingrowth. The DGA Resin option can be used to determine 90Sr, and if 91Y is also present, an ingrowth option with using DGA

  16. Floating plant can get uranium from seawater

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    A floating plant has been designed to extract uranium from seawater using solid adsorbents. Ore is removed from the adsorbent material by means of a solvent and concentrated in ion exchangers. Seawater is supplied to the adsorbent inside by wave energy and is based on the principle that waves will rush up a sloping plane that is partly submerged and fill a reservoir to a level higher than the still water level in the sea. The company projects that an offshore plant for recovering 600 tons of uranium/yr would comprise 22 floating concrete units, each measuring 430 x 75 meters

  17. The prediction of BRDFs from surface profile measurements

    International Nuclear Information System (INIS)

    Church, E.L.; Takacs, P.Z.; Leonard, T.A.

    1989-01-01

    This paper discusses methods of predicting the BRDF of smooth surfaces from profile measurements of their surface finish. The conversion of optical profile data to the BRDF at the same wavelength is essentially independent of scattering models, while the conversion of mechanical measurements, and wavelength scaling in general, are model dependent. Procedures are illustrated for several surfaces, including two from the recent HeNe BRDF round robin, and results are compared with measured data. Reasonable agreement is found except for surfaces which involve significant scattering from isolated surface defects which are poorly sampled in the profile data

  18. Microthermal Instrument for Measuring Surface Layer Seeing

    Science.gov (United States)

    Li, Xue-Bao; Zheng, Yan-Fang; Deng, Lin Hua; Xu, Guang

    2012-02-01

    Microthermal fluctuations are introduced by atmospheric turbulence very near the ground. In order to detect microthermal fluctuations at Fuxian Solar Observatory (FSO), a microthermal instrument has been developed. The microthermal instrument consists of a microthermal sensor, which is based on a Wheatstone bridge circuit and uses fine tungsten filaments as resistance temperature detectors, an associated signal processing unit, and a data collection, & communication subsystem. In this paper, after a brief introduction to surface layer seeing, we discuss the instrumentation behind the microthermal detector we have developed and then present the results obtained. The results of the evaluation indicate that the effect of the turbulent surface boundary layer to astronomical seeing would become sufficiently small when installing a telescope at a height of 16m or higher from the ground at FSO.

  19. Rivited panel surface measurement using photogrammetry

    Science.gov (United States)

    Merrick, W. D.; Lobb, V. B.; Lansing, F. L.; Stoller, F. W.

    1986-01-01

    Two riveted antenna panels on rings number 3 and 9 were removed from the 34m antenna at DSS-15, fixed in the leveled position and the surface was photographed indoors. The results from this pilot photogrammetric demonstration and diagnostics of panel surface contours, are presented. The photogrammetric network for each panel incorporated eight photographs, two from each of four camera stations and observed over 200 targets. The accuracy (1 sigma) of the XYZ coordinates for the error ellipsoids was + or - 0.013 mm (0.0005 inch). This level of precision relative to the object size corresponds roughly to 1 part in 250,000 which is superior to conventional dial sweep-arm template techniques by at least a factor of 4.

  20. Uranium from seawater

    International Nuclear Information System (INIS)

    1974-12-01

    The report concerns the possibilities of extracting uranium from seawater using either 'tidal' and 'pumped' schemes. It was decided to undertake an initial exercise on the pumped scheme. It was to take into account not only the direct energy requirements, but also the indirect energy inputs needed to produce the capital equipment, operating materials, etc. The report begins with a discussion of the technique of energy accounting, and the merits and limitations of the two principal approaches are compared. These are: 'Process Analysis' (or 'Energy Cost of Materials') and 'Input-Output Analysis' (or 'Energy Cost of Money'). A comparison is made between the energy cost of the tidal and pumped schemes, by both methods of analysis. A 'Best Estimate' is compiled calling on both methods, and this indicates that on an energy cost basis the pumped scheme is three times as expensive as the tidal scheme. Intermediate schemes are feasible, however. There is some evidence that the energy cost of an ore refining process with an initial concentration of 0.007% would be of the same order as that of the pumped seawater scheme. The energy cost of generating electricity using seawater uranium in an SGHWR is compared with the present UK generating system as a whole. (U.K.)

  1. Surface Temperature Measurement Using Hematite Coating

    Science.gov (United States)

    Bencic, Timothy J. (Inventor)

    2015-01-01

    Systems and methods that are capable of measuring temperature via spectrophotometry principles are discussed herein. These systems and methods are based on the temperature dependence of the reflection spectrum of hematite. Light reflected from these sensors can be measured to determine a temperature, based on changes in the reflection spectrum discussed herein.

  2. Concentration of 137Cs in seawater surrounding East Malaysia

    International Nuclear Information System (INIS)

    Yii, M.W.; Zaharudin, A.

    2007-01-01

    Studies of 137 Cs distribution in East Malaysia were carried out as part of a marine coastal environment project. The results of measurements will serve as baseline data and background reference level for Malaysia coastline. Twenty-one locations were identified along the coastline of East Malaysia, and from each location water samples were collected at the surface of the seawater. Ten near-shore locations were also selected and seawater was collected at three different depths. Large volumes of seawater were collected and the co-precipitation technique was employed to concentrate cesium. A known amount of 134 Cs tracer was added as yield determinant, followed by addition of copper(II) nitrate salt and a solution of potassium hexacyanoferrate(II) trihydrate, to precipitate the total cesium. The precipitate slurry was oven dried at 60 deg C for 1-2 days, finely ground and counted using gamma-ray spectrometry. The activity of 137 Cs was determined by measuring the peak area under the photopeak of the gamma-spectrum at 661 keV, which is equivalent to gamma-intensity corrected for detection efficiency, percentage of gamma-ray abundance of the radionuclide and recovery of 134 Cs tracer. There were no significant differences of 137 Cs activities both in surface and bottom water samples at 95% confidence level. The activity of 137 Cs (for all samples) was found to be in the range of 1.47 to 3.36 Bq/m 3 and 1.69 to 3.32 Bq/m 3 for Sabah and Sarawak, respectively. (author)

  3. Kinetics of adsorption of uranium from seawater by humic acids

    International Nuclear Information System (INIS)

    Heitkamp, D.; Wagener, K.

    1990-01-01

    The kinetics of the adsorption of uranium from seawater by humic acids fixed onto a polymer matrix was measured in a fluidized bed as a function of the grain size of the adsorbent and the flow velocity of the seawater. The adsorption rate was found to be governed by the diffusion of the uranium ions through the hydrodynamic surface layer of the adsorbent which is always formed in laminar flows of liquids. The measured rate constants are interpreted in terms of effective diffusion coefficients of 3.6 x 10 -5 cm 2 /s for uranyl ions and 1.8 x 10 -5 cm 2 /s for tricarbonatouranate ions in the surface layer. As a consequence of this kinetic behavior, the geometry of the adsorbent as well as the velocity of the water flow are relevant parameters for the amount of adsorbent needed for a projected extraction rate. This conclusion applies to all adsorption processes where diffusion through the hydrodynamic layer is the rate-determining kinetic step

  4. Seawater bicarbonate removal during hydrothermal circulation

    Science.gov (United States)

    Proskurowski, G. K.; Seewald, J.; Sylva, S. P.; Reeves, E.; Lilley, M. D.

    2013-12-01

    High temperature fluids sampled at hydrothermal vents represent a complex alteration product of water-rock reactions on a multi-component mixture of source fluids. Sources to high-temperature hydrothermal samples include the 'original' seawater present in the recharge limb of circulation, magmatically influenced fluids added at depth as well as any seawater entrained during sampling. High-temperature hydrothermal fluids are typically enriched in magmatic volatiles, with CO2 the dominant species, characterized by concentrations of 10's-100's of mmol/kg (1, 2). Typically, the high concentration of CO2 relative to background seawater bicarbonate concentrations (~2.3 mmol/kg) obscures a full analysis of the fate of seawater bicarbonate during high-temperature hydrothermal circulation. Here we present data from a suite of samples collected over the past 15 years from high-temperature hydrothermal vents at 9N, Endeavour, Lau Basin, and the MAR that have endmember CO2 concentrations less than 10 mmol/kg. Using stable and radiocarbon isotope measurements these samples provide a unique opportunity to examine the balance between 'original' seawater bicarbonate and CO2 added from magmatic sources. Multiple lines of evidence from multiple hydrothermal settings consistently points to the removal of ~80% of the 'original' 2.3 mmol/kg seawater bicarbonate. Assuming that this removal occurs in the low-temperature, 'recharge' limb of hydrothermal circulation, this removal process is widely occurring and has important contributions to the global carbon cycle over geologic time. 1. Lilley MD, Butterfield DA, Lupton JE, & Olson EJ (2003) Magmatic events can produce rapid changes in hydrothermal vent chemistry. Nature 422(6934):878-881. 2. Seewald J, Cruse A, & Saccocia P (2003) Aqueous volatiles in hydrothermal fluids from the Main Endeavour Field, northern Juan de Fuca Ridge: temporal variability following earthquake activity. Earth and Planetary Science Letters 216(4):575-590.

  5. Interferometric Surface Relief Measurements with Subnano/Picometer Height Resolution

    Science.gov (United States)

    Sysoev, Evgeny; Kosolobov, Sergey; Kulikov, Rodion; Latyshev, Alexander; Sitnikov, Sergey; Vykhristyuk, Ignat

    2017-10-01

    We present an optical interference system nanoprofiler MNP-1 designed for high-precision noncontact measurement of surface relief with subnanometer resolution (root mean square of measured values), based on partial scanning of interference signal. The paper describes the construction of the measurement system with Linnik interferometer and the algorithm for nanorelief surface reconstruction. Experimental measurement results of silicon sample with profile height of surface structure of one interatomic distance obtained by MNP-1 are shown. It was proposed to use an atomically smooth surface as the reference mirror in the interferometer MNP-1 that allowed us to measure monatomic steps of the presented silicon sample. Monatomic steps of 0.31 nm in height on silicon (111) surface were measured with resolution up to 5 pm.

  6. Monitoring and modeling infiltration-recharge dynamics of managed aquifer recharge with desalinated seawater

    OpenAIRE

    Ganot, Yonatan; Holtzman, Ran; Weisbrod, Noam; Nitzan, Ido; Katz, Yoram; Kurtzman, Daniel

    2016-01-01

    We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil sensors and observation...

  7. Monitoring and modeling infiltration–recharge dynamics of managed aquifer recharge with desalinated seawater

    OpenAIRE

    Ganot, Y.; Ganot, Y.; Holtzman, R.; Weisbrod, N.; Nitzan, I.; Katz, Y.; Kurtzman, D.

    2017-01-01

    We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil senso...

  8. Radioactivity Measurements on Glazed Ceramic Surfaces

    OpenAIRE

    Hobbs, Thomas G.

    2000-01-01

    A variety of commonly available household and industrial ceramic items and some specialty glass materials were assayed by alpha pulse counting and ion chamber voltage measurements for radioactivity concentrations. Identification of radionuclides in some of the items was performed by gamma spectroscopy. The samples included tableware, construction tiles and decorative tiles, figurines, and other products with a clay based composition. The concentrations of radioactivity ranged from near backgr...

  9. Piezotransistive GaN microcantilevers based surface work function measurements

    Science.gov (United States)

    Bayram, Ferhat; Khan, Digangana; Li, Hongmei; Maksudul Hossain, Md.; Koley, Goutam

    2018-04-01

    Surface work function (SWF) measurements using a piezotransistive III–nitride cantilever has been demonstrated on multiple surfaces. The minimum detectable surface potential change of 10 mV was achieved with a signal to noise ratio of 3. This method was applied to determine the surface potential changes due to exposure of 5 ppm NO2 in graphene and In2O3 thin film, simultaneously with conductivity changes. The potentiometric measurements yielded 100 and 80 mV potential changes in SWFs of graphene and In2O3 respectively, which matches very well with experimental data published earlier indicating the efficacy of this readily miniaturizable measurement technique.

  10. Comparative analyses of measured evapotranspiration for various land surfaces

    Science.gov (United States)

    Suat Irmak

    2016-01-01

    There is a significant lack of continuously measured ET data for multiple land surfaces in the same area to be able to make comparisons of water use rates of different agroecosystems. This research presentation will provide continuous evapotranspiration and other surface energy balance variables measured above multiple land use and management practices.

  11. Specific surface as a measure of burial diagenesis of chalk

    DEFF Research Database (Denmark)

    Borre, Mai Kirstine; Lind, Ida; Mortensen, Jeanette

    1997-01-01

    the relative importance of the three processes, simple models have been established to illustrate changes in pore space, particle size and -shape and the resulting trends in the specific surface. Specific surface and porosity of the samples were measured using image analysis on electron micrographs of polished...... sections. Using these simple models, trends in the measured specific surface can be interpred throughout the majority of the geological sequence....

  12. Development of material measures for performance verifying surface topography measuring instruments

    International Nuclear Information System (INIS)

    Leach, Richard; Giusca, Claudiu; Rickens, Kai; Riemer, Oltmann; Rubert, Paul

    2014-01-01

    The development of two irregular-geometry material measures for performance verifying surface topography measuring instruments is described. The material measures are designed to be used to performance verify tactile and optical areal surface topography measuring instruments. The manufacture of the material measures using diamond turning followed by nickel electroforming is described in detail. Measurement results are then obtained using a traceable stylus instrument and a commercial coherence scanning interferometer, and the results are shown to agree to within the measurement uncertainties. The material measures are now commercially available as part of a suite of material measures aimed at the calibration and performance verification of areal surface topography measuring instruments

  13. Biofouling control of industrial seawater cooling towers

    KAUST Repository

    Albloushi, Mohammed

    2017-11-01

    . Test results of GAC bio-filter showed that around 70 % removal of total organic carbon in the seawater feed was achieved and was effective in keeping the microbial growth to a minimum. The measured results from this study enable designers of seawater cooling towers to manage the biofouling problems when such cooling towers are extrapolated to a pilot scale.

  14. Multispectral In-situ Measurements of Organic Matter and Chlorophyll Fluorescence in Seawater: Documenting the Intrusion of the Mississippi River Plume in the West Florida Shelf

    Science.gov (United States)

    DelCastillo, Carlos E.; Coble, Paula G.; Conmy, Robyn N.; Mueller-Karger, Frank E.; Vanderbloomen, Lisa; Vargo, Gabriel A.

    2000-01-01

    We performed multispectral in-situ fluorescence measurement of colored dissolved organic matter and chlorophyll in surface water of the West Florida Shelf using West Labs Spectral absorption and Fluorescence Instrument (SAFIre). Continuous measurements underway allowed us to simultaneously map the dispersion of riverine organic material and chlorophyll on the shelf. By using two fluorescence emission ratios we were able to differentiate between riverine and marine CDOM. Our data also showed unusually high concentrations of CDOM offshore. These were attributed to an intrusion of the Mississippi River Plume. We performed limited comparisons between in-situ chlorophyll concentrations measured with SAFIre and chlorophyll values obtained from SeaWiFS satellite data using OC4 and MODIS algorithm. Our results show that, although both algorithms overestimated chlorophyll, MODIS performed better than OC4, particularly in areas with high CDOM concentrations. Analysis of the relationship between chlorophyll and CDOM concentrations within the study area showed regional variability causes by differences in river source.

  15. Automated nutrient analyses in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Whitledge, T.E.; Malloy, S.C.; Patton, C.J.; Wirick, C.D.

    1981-02-01

    This manual was assembled for use as a guide for analyzing the nutrient content of seawater samples collected in the marine coastal zone of the Northeast United States and the Bering Sea. Some modifications (changes in dilution or sample pump tube sizes) may be necessary to achieve optimum measurements in very pronounced oligotrophic, eutrophic or brackish areas. Information is presented under the following section headings: theory and mechanics of automated analysis; continuous flow system description; operation of autoanalyzer system; cookbook of current nutrient methods; automated analyzer and data analysis software; computer interfacing and hardware modifications; and trouble shooting. The three appendixes are entitled: references and additional reading; manifold components and chemicals; and software listings. (JGB)

  16. Seasonal and spatial variability of surface seawater fluorescence properties in the Baltic and Nordic Seas: results of lidar experiments Oceanologia 2007, no 49(1, pp. 59-69

    Directory of Open Access Journals (Sweden)

    Violetta Drozdowska

    2007-03-01

    Full Text Available The paper analyses experimental measurements of laser-induced fluorescence (LIF spectra in different seawaters. The fluorescence parameters, calculated from LIF spectra as the ratio of the integrals of fluorescence and Raman signal intensities, provide information about the relative changes in the concentrations of fluorescing molecules. Gathered during several cruises in 1994-2004 in the Baltic and Nordic Seas, all the data are presented as scatter plots of the fluorescence parameters of chlorophyll a (Chl a and coloured dissolved organic matter (CDOM. Satisfactory correlations between these two parameters were found a for open Nordic Seas waters, b for the southern Baltic in blooming periods only, and c for the Gulf of Gdańnsk in non-blooming periods only.

  17. Radioactivity Measurements on Glazed Ceramic Surfaces.

    Science.gov (United States)

    Hobbs, T G

    2000-01-01

    A variety of commonly available household and industrial ceramic items and some specialty glass materials were assayed by alpha pulse counting and ion chamber voltage measurements for radioactivity concentrations. Identification of radionuclides in some of the items was performed by gamma spectroscopy. The samples included tableware, construction tiles and decorative tiles, figurines, and other products with a clay based composition. The concentrations of radioactivity ranged from near background to about four orders of magnitude higher. Almost every nuclide identification test demonstrated some radioactivity content from one or more of the naturally occurring radionuclide series of thorium or uranium. The glazes seemed to contribute most of the activity, although a sample of unglazed pottery greenware showed some activity. Samples of glazing paints and samples of deliberately doped glass from the World War II era were included in the test, as was a section of foam filled poster board. A glass disc with known (232)Th radioactivity concentration was cast for use as a calibration source. The results from the two assay methods are compared, and a projection of sensitivity from larger electret ion chamber devices is presented.

  18. Corrosion in seawater systems

    International Nuclear Information System (INIS)

    Henrikson, S.

    1988-01-01

    Highly alloyed stainless steels have been exposed to natural chlorinated and chlorine-free seawater at 35 deg. C. Simulated tube-tubesheet joints, weld joints and galvanic couples with titanium, 90/10 CuNi and NiAl bronze were tested and evaluated for corrosion. The corrosion rates of various anode materials - zinc, aluminium and soft iron - were also determined. Finally the risk of hydrogen embrittlement of tubes of ferritic stainless steels and titanium as a consequence of cathodic protection was studied. An attempt was also made to explain the cracking mechanism of the ferritic steels by means of transmission electron microscopy. One important conclusion of the project is that chlorinated seawater is considerably more corrosive to stainless steels than chlorine-free water, whereas chlorination reduces the rate of galvanic corrosion of copper materials coupled to stainless steels. Hydrogen embrittlement of ferritic stainless steels and titanium as a consequence of cathodic protection of carbon steel or cast iron in the same structure can be avoided by strict potentiostatic control of the applied potential. (author)

  19. SGP Cloud and Land Surface Interaction Campaign (CLASIC): Measurement Platforms

    Energy Technology Data Exchange (ETDEWEB)

    MA Miller; R Avissar; LK Berg; SA Edgerton; ML Fischer; TJ Jackson; B. Kustas; PJ Lamb; G McFarquhar; Q Min; B Schmid; MS Torn; DD Tuner

    2007-06-01

    The Cloud and Land Surface Interaction Campaign (CLASIC) will be conducted from June 8 to June 30, 2007, at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site. Data will be collected using eight aircraft equipped with a variety of specialized sensors, four specially instrumented surface sites, and two prototype surface radar systems. The architecture of CLASIC includes a high-altitude surveillance aircraft and enhanced vertical thermodynamic and wind profile measurements that will characterize the synoptic scale structure of the clouds and the land surface within the ACRF SGP site. Mesoscale and microscale structures will be sampled with a variety of aircraft, surface, and radar observations. An overview of the measurement platforms that will be used during the CLASIC are described in this report. The coordination of measurements, especially as it relates to aircraft flight plans, will be discussed in the CLASIC Implementation Plan.

  20. A Study on 3-Dimensional Surface Measurement using Confocal Principle

    International Nuclear Information System (INIS)

    Kang, Young June; Song, Dae Ho; You, Weon Jae

    2001-01-01

    In modern industry, the accuracy and the sulfate-finish requirements for machined parts have been becoming ever more stringent. In addition, the measurement and understanding of surface topography is rapidly attracting the attention of the physicist and chemist as well as the engineer. Optical measuring method is used in vibration measurement, crack and defect detection with the advent of opto-mechatronics, and it is expected to play an important role in surface topography. In this study, the principle of confocal microscope is described, and the advanced 3-D surface measuring system that has better performance than the traditional confocal microscope is developed. Suitable fixtures arc developed and integrated with the computer system for generating 3-D surface and form data. Software for data acquisition and analysis of various parameters in surface geometrical features has been developed

  1. ROUGHNESS ON WOOD SURFACES AND ROUGHNESS MEASUREMENT METHODS

    Directory of Open Access Journals (Sweden)

    İsmail Aydın

    2003-04-01

    Full Text Available Some visual characteristics of wood such as color, pattern and texture determine the quality of manufactured products. Surface properties of wood material are important both in production and marketing after production. Initial studies related to the roughness of wood surface were begun in early 1950’s. However, no general agreed standardization can not have been developed for wood surfaces. Surface roughness of wood is function of the production process, product type and the natural anatomical properties of wood. Contact and non-contact tracing methods are used to measure of wood surface roughness. Surface roughness also affects the gluability and wettability of wood surfaces. The success in finishing also depends on the surface roughness of wood.

  2. Seawater 234U/238U recorded by modern and fossil corals

    Science.gov (United States)

    Chutcharavan, Peter M.; Dutton, Andrea; Ellwood, Michael J.

    2018-03-01

    U-series dating of corals is a crucial tool for generating absolute chronologies of Late Quaternary sea-level change and calibrating the radiocarbon timescale. Unfortunately, coralline aragonite is susceptible to post-depositional alteration of its primary geochemistry. One screening technique used to identify unaltered corals relies on the back-calculation of initial 234U/238U activity (δ234Ui) at the time of coral growth and implicitly assumes that seawater δ234U has remained constant during the Late Quaternary. Here, we test this assumption using the most comprehensive compilation to date of coral U-series measurements. Unlike previous compilations, this study normalizes U-series measurements to the same decay constants and corrects for offsets in interlaboratory calibrations, thus reducing systematic biases between reported δ234U values. Using this approach, we reassess (a) the value of modern seawater δ234U, and (b) the evolution of seawater δ234U over the last deglaciation. Modern coral δ234U values (145.0 ± 1.5‰) agree with previous measurements of seawater and modern corals only once the data have been normalized. Additionally, fossil corals in the surface ocean display δ234Ui values that are ∼5-7‰ lower during the last glacial maximum regardless of site, taxon, or diagenetic setting. We conclude that physical weathering of U-bearing minerals exposed during ice sheet retreat drives the increase in δ234U observed in the oceans, a mechanism that is consistent with the interpretation of the seawater Pb-isotope signal over the same timescale.

  3. An Evaluation of Carbon Steel Corrosion Under Stagnant Seawater Conditions

    National Research Council Canada - National Science Library

    Lee, Jason

    2004-01-01

    Corrosion, of 1020 carbon steel coupons in, natural seawater over a six-month period was more aggressive under stagnant anaerobic conditions than stagnant aerobic conditions as measured by weight loss...

  4. Partial compensation interferometry for measurement of surface parameter error of high-order aspheric surfaces

    Science.gov (United States)

    Hao, Qun; Li, Tengfei; Hu, Yao

    2018-01-01

    Surface parameters are the properties to describe the shape characters of aspheric surface, which mainly include vertex radius of curvature (VROC) and conic constant (CC). The VROC affects the basic properties, such as focal length of an aspheric surface, while the CC is the basis of classification for aspheric surface. The deviations of the two parameters are defined as surface parameter error (SPE). Precisely measuring SPE is critical for manufacturing and aligning aspheric surface. Generally, SPE of aspheric surface is measured directly by curvature fitting on the absolute profile measurement data from contact or non-contact testing. And most interferometry-based methods adopt null compensators or null computer-generated holograms to measure SPE. To our knowledge, there is no effective way to measure SPE of highorder aspheric surface with non-null interferometry. In this paper, based on the theory of slope asphericity and the best compensation distance (BCD) established in our previous work, we propose a SPE measurement method for high-order aspheric surface in partial compensation interferometry (PCI) system. In the procedure, firstly, we establish the system of two element equations by utilizing the SPE-caused BCD change and surface shape change. Then, we can simultaneously obtain the VROC error and CC error in PCI system by solving the equations. Simulations are made to verify the method, and the results show a high relative accuracy.

  5. Effect of different seawater Mg

    NARCIS (Netherlands)

    Mewes, A.; Langer, G.; de Nooijer, L.J.; Bijma, J.; Reichart, G.J.

    2014-01-01

    Magnesium, incorporated in foraminiferal calcite (Mg/CaCC), is used intensively to reconstruct past seawater temperatures but, in addition to temperature, the Mg/CaCC of foraminiferal tests also depends on the ratio of Mg and Ca in seawater (Mg/CaSW). The physiological mechanisms responsible for

  6. Automatic Measurement of Low Level Contamination on Concrete Surfaces

    International Nuclear Information System (INIS)

    Tachibana, M.; Itoh, H.; Shimada, T.; Yanagihara, S.

    2002-01-01

    Automatic measurement of radioactivity is necessary for considering cost effectiveness in final radiological survey of building structures in decommissioning nuclear facilities. The RAPID (radiation measuring pilot device for surface contamination) was developed to be applied to automatic measurement of low level contamination on concrete surfaces. The RAPID has a capability to measure contamination with detection limit of 0.14 Bq/cm2 for 60Co in 30 seconds of measurement time and its efficiency is evaluated to be 5 m2/h in a normal measurement option. It was confirmed that low level contamination on concrete surfaces could be surveyed by the RAPID efficiently compared with direct measurement by workers through its actual application

  7. Open questions in surface topography measurement: a roadmap

    International Nuclear Information System (INIS)

    Leach, Richard; Evans, Christopher; He, Liangyu; Davies, Angela; Duparré, Angela; Henning, Andrew; Jones, Christopher W; O’Connor, Daniel

    2015-01-01

    Control of surface topography has always been of vital importance for manufacturing and many other engineering and scientific disciplines. However, despite over one hundred years of quantitative surface topography measurement, there are still many open questions. At the top of the list of questions is ‘Are we getting the right answer?’ This begs the obvious question ‘How would we know?’ There are many other questions relating to applications, the appropriateness of a technique for a given scenario, or the relationship between a particular analysis and the function of the surface. In this first ‘open questions’ article we have gathered together some experts in surface topography measurement and asked them to address timely, unresolved questions about the subject. We hope that their responses will go some way to answer these questions, address areas where further research is required, and look at the future of the subject. The first section ‘Spatial content characterization for precision surfaces’ addresses the need to characterise the spatial content of precision surfaces. Whilst we have been manufacturing optics for centuries, there still isn’t a consensus on how to specify the surface for manufacture. The most common three methods for spatial characterisation are reviewed and compared, and the need for further work on quantifying measurement uncertainties is highlighted. The article is focussed on optical surfaces, but the ideas are more pervasive. Different communities refer to ‘figure, mid-spatial frequencies, and finish’ and ‘form, waviness, and roughness’, but the mathematics are identical. The second section ‘Light scattering methods’ is focussed on light scattering techniques; an important topic with in-line metrology becoming essential in many manufacturing scenarios. The potential of scattering methods has long been recognized; in the ‘smooth surface limit’ functionally significant relationships can be derived from first

  8. A study of Al-Zn-Sn alloy sacrificial anode cathodic protection requirements for structure used in seawater

    International Nuclear Information System (INIS)

    Siti Radiah Mohd Kamarudin

    2009-01-01

    Full text: The study will be focused on the alloying of Aluminum alloy sacrificial anode. The work will explore, evaluate and assess the effectiveness of Al-Zn-Sn alloy sacrificial anode tested in tropical seawater. This study is directed toward the development of new and more comprehensive data that will provide a technical basis for improved, more cost - effective guidelines for prediction, verification and optimization of cathodic protection requirements for structures used in tropical seawater. Furthermore, this study will also evaluate the potential and benefits of laboratory research upon marine corrosion without needed to be in the actual marine environment. The influence of alloy composition on the electrochemical properties of this Al-Zn-Sn will be determined by various tasks of testing which fully conducted in the laboratory. SEM and EDAX analysis will be employed in order to characterize surface structure of Al-Zn-Sn alloy. The corrosion measurement analyzer will be used by means to identify the electrochemical properties such as potential, corrosion rate and passivation of Al-Zn-Sn sacrificial anode when immersed in seawater. The relationship between morphological structure and electrochemical results will be examined. The data obtained will be used to evaluate the performance of Al-Zn-Sn alloy as a sacrificial anode cathodic protection for structure used in tropical seawater. Further verification will be made to testify that the Al-Zn-Sn alloy meets the quality requirements to be used as a sacrificial anode in tropical seawater. (author)

  9. Measurement of Dynamic Friction Coefficient on the Irregular Free Surface

    International Nuclear Information System (INIS)

    Yeom, S. H.; Seo, K. S.; Lee, J. H.; Lee, K. H.

    2007-01-01

    A spent fuel storage cask must be estimated for a structural integrity when an earthquake occurs because it freely stands on ground surface without a restriction condition. Usually the integrity estimation for a seismic load is performed by a FEM analysis, the friction coefficient for a standing surface is an important parameter in seismic analysis when a sliding happens. When a storage cask is placed on an irregular ground surface, measuring a friction coefficient of an irregular surface is very difficult because the friction coefficient is affected by the surface condition. In this research, dynamic friction coefficients on the irregular surfaces between a concrete cylinder block and a flat concrete slab are measured with two methods by one direction actuator

  10. Measurement of near neighbor separations of surface atoms

    International Nuclear Information System (INIS)

    Cohen, P.I.

    Two techniques are being developed to measure the nearest neighbor distances of atoms at the surfaces of solids. Both measures extended fine structure in the excitation probability of core level electrons which are excited by an incident electron beam. This is an important problem because the structures of most surface systems are as yet unknown, even though the location of surface atoms is the basis for any quantitative understanding of the chemistry and physics of surfaces and interfaces. These methods would allow any laboratory to make in situ determinations of surface structure in conjunction with most other laboratory probes of surfaces. Each of these two techniques has different advantages; further, the combination of the two will increase confidence in the results by reducing systematic error in the data analysis

  11. Surface deposition measurements of the TMI-2 gross decontamination experiment

    International Nuclear Information System (INIS)

    McIssac, C.V.; Hetzer, D.C.

    1982-01-01

    In order to measure the effectiveness of the gross decontamination experiment (principally a water spray technique) performed in the TMI-2 reactor building, the Technical Information and Examination Program's Radiation and Environment personnel made surface activity measurements before and after the experiment. In conjunction with surface sampling, thermoluminescent dosimeter (TLD) and gamma spectrometry measurements were also performed to distinguish between radiation fields and contamination. The surface sampler used to collect samples from external surfaces within the reactor building is a milling tool having four major components: a 1.27-cm constant-speed drill; a drill support assembly that allows setting sample penetration depth; filter cartridges for intake air purification and sample collection; and an air pump that forces air across the surface being sampled and through the sample filter cartridge

  12. Surface and interfacial tension measurement, theory, and applications

    CERN Document Server

    Hartland, Stanley

    2004-01-01

    This edited volume offers complete coverage of the latest theoretical, experimental, and computer-based data as summarized by leading international researchers. It promotes full understanding of the physical phenomena and mechanisms at work in surface and interfacial tensions and gradients, their direct impact on interface shape and movement, and their significance to numerous applications. Assessing methods for the accurate measurement of surface tension, interfacial tension, and contact angles, Surface and Interfacial Tension presents modern simulations of complex interfacial motions, such a

  13. NASA's Space Lidar Measurements of Earth and Planetary Surfaces

    Science.gov (United States)

    Abshire, James B.

    2010-01-01

    A lidar instrument on a spacecraft was first used to measure planetary surface height and topography on the Apollo 15 mission to the Moon in 1971, The lidar was based around a flashlamp-pumped ruby laser, and the Apollo 15-17 missions used them to make a few thousand measurements of lunar surface height from orbit. With the advent of diode pumped lasers in the late 1980s, the lifetime, efficiency, resolution and mass of lasers and space lidar all improved dramatically. These advances were utilized in NASA space missions to map the shape and surface topography of Mars with > 600 million measurements, demonstrate initial space measurements of the Earth's topography, and measured the detailed shape of asteroid. NASA's ICESat mission in Earth orbit just completed its polar ice measurement mission with almost 2 billion measurements of the Earth's surface and atmosphere, and demonstrated measurements to Antarctica and Greenland with a height resolution of a few em. Space missions presently in cruise phase and in operation include those to Mercury and a topographic mapping mission of the Moon. Orbital lidar also have been used in experiments to demonstrate laser ranging over planetary distances, including laser pulse transmission from Earth to Mars orbit. Based on the demonstrated value of the measurements, lidar is now the preferred measurement approach for many new scientific space missions. Some missions planned by NASA include a planetary mission to measure the shape and dynamics of Europa, and several Earth orbiting missions to continue monitoring ice sheet heights, measure vegetation heights, assess atmospheric CO2 concentrations, and to map the Earth surface topographic heights with 5 m spatial resolution. This presentation will give an overview of history, ongoing work, and plans for using space lidar for measurements of the surfaces of the Earth and planets.

  14. Fuel Production from Seawater and Fuel Cells Using Seawater.

    Science.gov (United States)

    Fukuzumi, Shunichi; Lee, Yong-Min; Nam, Wonwoo

    2017-11-23

    Seawater is the most abundant resource on our planet and fuel production from seawater has the notable advantage that it would not compete with growing demands for pure water. This Review focuses on the production of fuels from seawater and their direct use in fuel cells. Electrolysis of seawater under appropriate conditions affords hydrogen and dioxygen with 100 % faradaic efficiency without oxidation of chloride. Photoelectrocatalytic production of hydrogen from seawater provides a promising way to produce hydrogen with low cost and high efficiency. Microbial solar cells (MSCs) that use biofilms produced in seawater can generate electricity from sunlight without additional fuel because the products of photosynthesis can be utilized as electrode reactants, whereas the electrode products can be utilized as photosynthetic reactants. Another important source for hydrogen is hydrogen sulfide, which is abundantly found in Black Sea deep water. Hydrogen produced by electrolysis of Black Sea deep water can also be used in hydrogen fuel cells. Production of a fuel and its direct use in a fuel cell has been made possible for the first time by a combination of photocatalytic production of hydrogen peroxide from seawater and dioxygen in the air and its direct use in one-compartment hydrogen peroxide fuel cells to obtain electric power. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A computer-aided surface roughness measurement system

    International Nuclear Information System (INIS)

    Hughes, F.J.; Schankula, M.H.

    1983-11-01

    A diamond stylus profilometer with computer-based data acquisitions/analysis system is being used to characterize surfaces of reactor components and materials, and to examine the effects of surface topography on thermal contact conductance. The current system is described; measurement problems and system development are discussed in general terms and possible future improvements are outlined

  16. Measuring Forces between Oxide Surfaces Using the Atomic Force Microscope

    DEFF Research Database (Denmark)

    Pedersen, Henrik Guldberg; Høj, Jakob Weiland

    1996-01-01

    The interactions between colloidal particles play a major role in processing of ceramics, especially in casting processes. With the Atomic Force Microscope (AFM) it is possible to measure the inter-action force between a small oxide particle (a few micron) and a surface as function of surface...

  17. Drop shape visualization and contact angle measurement on curved surfaces.

    Science.gov (United States)

    Guilizzoni, Manfredo

    2011-12-01

    The shape and contact angles of drops on curved surfaces is experimentally investigated. Image processing, spline fitting and numerical integration are used to extract the drop contour in a number of cross-sections. The three-dimensional surfaces which describe the surface-air and drop-air interfaces can be visualized and a simple procedure to determine the equilibrium contact angle starting from measurements on curved surfaces is proposed. Contact angles on flat surfaces serve as a reference term and a procedure to measure them is proposed. Such procedure is not as accurate as the axisymmetric drop shape analysis algorithms, but it has the advantage of requiring only a side view of the drop-surface couple and no further information. It can therefore be used also for fluids with unknown surface tension and there is no need to measure the drop volume. Examples of application of the proposed techniques for distilled water drops on gemstones confirm that they can be useful for drop shape analysis and contact angle measurement on three-dimensional sculptured surfaces. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Device for radiometric measurement, e.g. of surface density

    International Nuclear Information System (INIS)

    Gregor, J.; Kopl, F.

    1973-01-01

    A design is described of a device for radiometric measurements, such as of material surface density, thickness of coating layers, surface moisture, and for the analysis of chemical composition. The device uses backscattered radiation indicated by two ionization chambers with gas filling; the radiation source is placed in between the chambers. (J.K.)

  19. Laboratory measurements of dusty surface charging in plasma.

    Science.gov (United States)

    Chou, Kevin; Wang, Joseph

    2017-09-01

    A novel method is developed to study the charging of a conducting surface covered by a thin dust layer in plasma. The potential profile in the dust layer and the floating potential of the surface underneath are measured directly by embedding conducting wires in the dust and connecting the wires to a measurement plate outside the vacuum chamber, where a Trek non-contacting electrostatic voltmeter measures the floating potential of the measurement plate. Laboratory experiments are carried out to study plasma charging of a conducting plate covered by lunar dust simulant, JSC-1A. The results show that the plate potential is dependent on both the ambient plasma condition and the dust layer thickness. The current balance condition controls the floating potential of the dust surface while the dust layer acts as a capacitor and controls the potential of the plate with respect to the dust surface. Hence, a dust covered conducting plate will be charged more negatively than a clean plate.

  20. Sulfate was a trace constituent of Archean seawater

    DEFF Research Database (Denmark)

    Crowe, Sean Andrew; Paris, Guillaume; Katsev, Sergei

    2014-01-01

    In the low-oxygen Archean world (>2400 million years ago), seawater sulfate concentrations were much lower than today, yet open questions frustrate the translation of modern measurements of sulfur isotope fractionations into estimates of Archean seawater sulfate concentrations. In the water column...... Archean seawater sulfate concentrations of less than 2.5 micromolar. At these low concentrations, marine sulfate residence times were likely 10(3) to 10(4) years, and sulfate scarcity would have shaped early global biogeochemical cycles, possibly restricting biological productivity in Archean oceans....

  1. Iodine-129 in Seawater Offshore Fukushima: distribution, inorganic speciation, sources, and budget

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Povinec, Pavel P.; Zhang, Luyuan

    2013-01-01

    in seawater depth profiles collected offshore Fukushima in June 2011. Significantly elevated 129I concentrations in surface water were observed with the highest 129I/127I atomic ratio of 2.2 × 10-9 in the surface seawater 40 km offshore Fukushima. Iodide was found as the dominant species of 129I, while stable...

  2. Accuracy of Surface Plate Measurements - General Purpose Software for Flatness Measurement

    NARCIS (Netherlands)

    Meijer, J.; Heuvelman, C.J.

    1990-01-01

    Flatness departures of surface plates are generally obtained from straightness measurements of lines on the surface. A computer program has been developed for on-line measurement and evaluation, based on the simultaneous coupling of measurements in all grid points. Statistical methods are used to

  3. Cantilever measurements of surface stress, surface reconstruction, film stress and magnetoelastic stress of monolayersc

    Directory of Open Access Journals (Sweden)

    Jürgen Kirschner

    2008-07-01

    Full Text Available We review the application of cantilever-based stress measurements in surface science and magnetism. The application of thin (thickness appr. 0.1 mm single crystalline substrates as cantilevers has been used successfully to measure adsorbate-induced surface stress changes, lattice misfit induced film stress, and magneto-elastic stress of ferromagnetic monolayers. Surface stress changes as small as 0.01 N/m can be readily measured, and this translates into a sensitivity for adsorbate-coverage well below 0.01 of one layer. Stress as large as several GPa, beyond the elasticity limits of high strength materials, is measured, and it is ascribed to the lattice misfit between film and substrate. Our results point at the intimate relation between surface stress and surface reconstruction, stress-induced structural changes in epitaxially strained films, and strain-induced modifications of the magneto-elastic coupling in ferromagnetic monolayers.

  4. Cantilever measurements of surface stress, surface reconstruction, film stress and magnetoelastic stress of monolayers.

    Science.gov (United States)

    Sander, Dirk; Tian, Zhen; Kirschner, Jürgen

    2008-07-29

    We review the application of cantilever-based stress measurements in surface science and magnetism. The application of thin (thickness appr. 0.1 mm) single crystalline substrates as cantilevers has been used successfully to measure adsorbate-induced surface stress changes, lattice misfit induced film stress, and magneto-elastic stress of ferromagnetic monolayers. Surface stress changes as small as 0.01 N/m can be readily measured, and this translates into a sensitivity for adsorbate-coverage well below 0.01 of one layer. Stress as large as several GPa, beyond the elasticity limits of high strength materials, is measured, and it is ascribed to the lattice misfit between film and substrate. Our results point at the intimate relation between surface stress and surface reconstruction, stress-induced structural changes in epitaxially strained films, and strain-induced modifications of the magneto-elastic coupling in ferromagnetic monolayers.

  5. Summations over equilaterally triangulated surfaces and the critical string measure

    Science.gov (United States)

    Smit, Dirk-Jan

    1992-01-01

    We propose a new approach to the summation over dynamically triangulated Riemann surfaces which does not rely on properties of the potential in a matrix model. Instead, we formulate a purely algebraic discretization of critical string path integral. This is combined with a technique which assigns to each equilateral triangulation of a two-dimensional surface a Riemann surface defined over a certain finite extension of the field of rational numbers, i.e. an arthmetic surface. Thus we establish a new formulation in which the sum over randomly triangulated surfaces defines an invariant measure on the moduli space of arithmetic surfaces. It is shown that because of this it is far from obvious that this measure for large genera approximates the measure defined by the continuum theory, i.e. Liouville theory or critical string theory. In low genus this subtlety does not exist. In the case of critical string theory we explicity compute the volume of the moduli space of arithmetic surfaces in terms of the modular height function and show that for low genus it approximates correctly the continuum measure. We also discuss a continuum limit which bears some resemblance with a double scaling limit in matrix models.

  6. Summations over equilaterally triangulated surfaces and the critical string measure

    International Nuclear Information System (INIS)

    Smit, D.J.; Lawrence Berkeley Lab., CA

    1992-01-01

    We propose a new approach to the summation over dynamically triangulated Riemann surfaces which does not rely on properties of the potential in a matrix model. Instead, we formulate a purely algebraic discretization of critical string path integral. This is combined with a technique which assigns to each equilateral triangulation of a two-dimensional surface a Riemann surface defined over a certain finite extension of the field of rational numbers, i.e. an arithmetic surface. Thus we establish a new formulated in which the sum over randomly triangulated surfaces defines an invariant measure on the moduli space of arithmetic surfaces. It is shown that because of this it is far from obvious that this measure for large genera approximates the measure defined by the continuum theory, i.e. Liouville theory or critical string theory. In low genus this subtlety does not exist. In the case of critical string theory we explicitly compute the volume of the moduli space of arithmetic surfaces in terms of the modular height function and show that for low genus it approximates correctly the continuum measure. We also discuss a continuum limit which bears some resemblance with a double scaling limit in matrix models. (orig.)

  7. Measuring evaporation from soil surfaces for environmental and ...

    African Journals Online (AJOL)

    ... in many aspects of environmental geotechnics and waste management. The paper describes the measurements made to assess the surface energy balance as well as its analysis, and presents the results of typical measurements. It also presents numerical values of the parameters and constants needed for the analysis.

  8. Sensitivity of surface resistance measurement of HTS thin films by ...

    Indian Academy of Sciences (India)

    field distribution in the resonators. The microwave surface resistance of the superconducting sample is then extracted from the measured Q value as a function of temperature. The sensitivity of the Rs measurement, that is, the relative change in the Q value with the change in the Rs value is determined for each resonator.

  9. Measurement of tendon reflexes by surface electromyography in normal subjects

    NARCIS (Netherlands)

    Stam, J.; van Crevel, H.

    1989-01-01

    A simple method for measuring the tendon reflexes was developed. A manually operated, electronic reflex hammer was applied that enabled measurement of the strength of tendon taps. Reflex responses were recorded by surface electromyography. Stimulus-response relations and latencies of tendon reflexes

  10. Estimating the breast surface using UWB microwave monostatic backscatter measurements.

    Science.gov (United States)

    Winters, David W; Shea, Jacob D; Madsen, Ernest L; Frank, Gary R; Van Veen, Barry D; Hagness, Susan C

    2008-01-01

    This paper presents an algorithm for estimating the location of the breast surface from scattered ultrawideband (UWB) microwave signals recorded across an antenna array. Knowing the location of the breast surface can improve imaging performance if incorporated as a priori information into recently proposed microwave imaging algorithms. These techniques transmit low-power microwaves into the breast using an antenna array, which in turn measures the scattered microwave signals for the purpose of detecting anomalies or changes in the dielectric properties of breast tissue. Our proposed surface identification algorithm consists of three procedures, the first of which estimates M points on the breast surface given M channels of measured microwave backscatter data. The second procedure applies interpolation and extrapolation to these M points to generate N > M points that are approximately uniformly distributed over the breast surface, while the third procedure uses these N points to generate a 3-D estimated breast surface. Numerical as well as experimental tests indicate that the maximum absolute error in the estimated surface generated by the algorithm is on the order of several millimeters. An error analysis conducted for a basic microwave radar imaging algorithm (least-squares narrowband beamforming) indicates that this level of error is acceptable. A key advantage of the algorithm is that it uses the same measured signals that are used for UWB microwave imaging, thereby minimizing patient scan time and avoiding the need for additional hardware.

  11. Mapping surface soil moisture with L-band radiometric measurements

    Science.gov (United States)

    Wang, James R.; Shiue, James C.; Schmugge, Thomas J.; Engman, Edwin T.

    1989-01-01

    A NASA C-130 airborne remote sensing aircraft was used to obtain four-beam pushbroom microwave radiometric measurements over two small Kansas tall-grass prairie region watersheds, during a dry-down period after heavy rainfall in May and June, 1987. While one of the watersheds had been burned 2 months before these measurements, the other had not been burned for over a year. Surface soil-moisture data were collected at the time of the aircraft measurements and correlated with the corresponding radiometric measurements, establishing a relationship for surface soil-moisture mapping. Radiometric sensitivity to soil moisture variation is higher in the burned than in the unburned watershed; surface soil moisture loss is also faster in the burned watershed.

  12. Light Penetration in Seawater Polluted by Dispersed Oil: Results of Radiative Transfer Modelling

    Science.gov (United States)

    Haule, K.; Darecki, M.; Toczek, H.

    2015-11-01

    The downwelling light in seawater is shaped by natural seawater constituents as well as by some external substances which can occur locally and temporally. In this study we focused on dispersed oil droplets which can be found in seawater after an oil spill or in the consequence of intensive shipping, oil extraction and transportation. We applied our modified radiative transfer model based on Monte Carlo code to evaluate the magnitude of potential influence of dispersed oil droplets on the downwelling irradiance and the depth of the euphotic zone. Our model was validated on the basis of in situ measurements for natural (unpolluted) seawater in the Southern Baltic Sea, resulting in less than 5% uncertainty. The optical properties of dispersed Petrobaltic crude oil were calculated on the basis of Mie theory and involved into radiative transfer model. We found that the changes in downwelling light caused by dispersed oil depend on several factors such as oil droplet concentration, size distribution, and the penetration depth (i.e. vertical range of oil droplets occurrence below sea surface). Petrobaltic oil droplets of submicron sizes and penetration depth of 5 m showed a potentially detectable reduction in the depth of the euphotic zone of 5.5% at the concentration of only 10 ppb. Micrometer-sized droplets needed 10 times higher concentration to give a similar effect. Our radiative transfer model provided data to analyse and discuss the influence of each factor separately. This study contributes to the understanding of the change in visible light penetration in seawater affected by dispersed oil.

  13. Strontium (Sr) separation from seawater using titanate adsorbents: Effects of seawater matrix ions on Sr sorption behavior

    Science.gov (United States)

    Ryu, Jungho; Hong, Hye-jin; Ryu, Taegong; Park, In-Su

    2017-04-01

    Strontium (Sr) which has many industrial applications such as ferrite magnet, ceramic, and fire works exists in seawater with the concentration of approximately 7 mg/L. In previous report estimating economic potential on recovery of various elements from seawater in terms of their commercial values and concentrations in seawater, Sr locates upper than approximate break-even line, which implies Sr recovery from seawater can be potentially profitable. Recently, Sr separation from seawater has received great attention in the environmental aspect after Fukushima Nuclear Power Plant (NPP) accident which released much amount of radioactive Sr and Cs. Accordingly, the efficient separation of radioactive elements released to seawater has become critical as an important technological need as well as their removal from radioactive wastes. So far, it has been introduced to separate Sr from aqueous media by various methods including solvent extraction, adsorption by solid materials, and ion exchange. Among them, the adsorption technique using solid adsorbents is of great interest for selectively separating Sr from seawater with respect to low concentration level of Sr. In this study, we synthesized titanate nanotube (TiNT) by simple hydrothermal reaction, characterized its physicochemical properties, and systematically evaluated Sr sorption behavior under various reaction conditions corresponding to seawater environment. The synthesized TiNT exhibited the fibril-type nanotube structure with high specific surface area of 260 m2/g. The adsorption of Sr on TiNT rapidly occurred following pseudo-second-order kinetic model, and was in good agreement with Langmuir isotherm model, indicating maximum adsorption capacity of 97 mg/g. Based on Sr uptake and Na release with stoichiometric balance, sorption mechanism of Sr on TiNT was found to be ion-exchange between Na in TiNT lattice and Sr in solution phase, which was also confirmed by XRD and Raman analysis. Among competitive ions, Ca

  14. Indirect measurement of near-surface velocity and pressure fields based on measurement of moving free surface profiles

    International Nuclear Information System (INIS)

    Sibamoto, Yasuteru; Nakamura, Hideo

    2005-01-01

    A non-intrusive technique for measurement of the velocity and pressure fields adjacent to a moving fluid surface is developed. The technique is based on the measurement of fluid surface profile. The velocity and pressure fields are derived with use of the boundary element method (BEM) by seeking for an incompressible flow field that satisfies the kinematic boundary condition imposed by the time-dependent fluid surface profile. The proposed technique is tested by deriving the velocity and pressure fields inversely from the fluid surface profiles obtained by a forward BEM calculation of fluid surface response to externally-imposed pressure. The inverse calculation results show good agreement with the imposed pressure distribution in the forward calculation. (author)

  15. Roughness in Surface Force Measurements: Extension of DLVO Theory To Describe the Forces between Hafnia Surfaces.

    Science.gov (United States)

    Eom, Namsoon; Parsons, Drew F; Craig, Vincent S J

    2017-07-06

    The interaction between colloidal particles is commonly viewed through the lens of DLVO theory, whereby the interaction is described as the sum of the electrostatic and dispersion forces. For similar materials acting across a medium at pH values remote from the isoelectric point the theory typically involves an electrostatic repulsion that is overcome by dispersion forces at very small separations. However, the dominance of the dispersion forces at short separations is generally not seen in force measurements, with the exception of the interaction between mica surfaces. The discrepancy for silica surfaces has been attributed to hydration forces, but this does not explain the situation for titania surfaces where the dispersion forces are very much larger. Here, the interaction forces between very smooth hafnia surfaces have been measured using the colloid probe technique and the forces evaluated within the DLVO framework, including both hydration forces and the influence of roughness. The measured forces across a wide range of pH at different salt concentrations are well described with a single parameter for the surface roughness. These findings show that even small degrees of surface roughness significantly alter the form of the interaction force and therefore indicate that surface roughness needs to be included in the evaluation of surface forces between all surfaces that are not ideally smooth.

  16. Measuring and modeling surface sorption dynamics of organophosphate flame retardants on impervious surfaces

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data presented in this data file is a product of a journal publication. The dataset contains measured and model predicted OPFRs gas-phase and surface-phase...

  17. Surface Moisture Measurement System Operation and Maintenance Manual

    International Nuclear Information System (INIS)

    Ritter, G.A.; Pearce, K.L.; Stokes, T.L.

    1995-12-01

    This operations and maintenance manual addresses deployment, equipment and field hazards, operating instructions, calibration verification, removal, maintenance, and other pertinent information necessary to safely operate and store the Surface Moisture Measurement System (SMMS) and Liquid Observation Well Moisture Measurement System (LOWMMS). These systems were developed primarily in support of Tank Waste Remediation System (TWRS) Safety Programs for moisture measurement in organic and ferrocyanide watch list tanks

  18. Practical aspects of tritium measurement in ground and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Nitzsche, O. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik; Hebert, D. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik

    1997-03-01

    Tritium measurements are a powerful tool in hydrological and hydrogeological investigations for detecting mean residence times of several water reservoirs. Due to the low tritium activities in precipitation, ground and surface waters a low level measurement is necessary. Therefore often the liquid scintillation counting after an electrolytic enrichment of water is used. In this paper some practical aspects and problems of measurement are discussed and the problem of contamination in low level laboratories is shown. (orig.)

  19. Plastic Deformations of Measured Object Surface in Contact with Undeformable Surface of Measuring Tool

    Directory of Open Access Journals (Sweden)

    Kowalik Marek

    2016-10-01

    Full Text Available Measuring errors caused by deformation (flattening of a measured object appear under the influence of pressure force and weight of the measured object. Plastic strain, arising at the contact of a measured object and an undeformable contact tip of a measuring device, can be calculated by applying the Hertz plastic solution and the hypothesis of plastic strain. In a small area of contact between two bodies pressing against one another with force F, there appears the so-called contact stress. It can sometime reach very high values, exceeding the yield point, even when the contact pressure is relatively small. In the present work, the authors describe a theoretical solution to the problem of plastic strain between two bodies. The derived relationships enable to calculate force F during measurements of a deformable object by means of an instrument with an undeformable, spherical measuring tip. By applying the τmax hypothesis, a solution was obtained for the force F in an inexplicit form. The theoretical solution was verified with the digital simulation and experimental measurement. With the FEM method, the limit length gage was modeled in interaction with the measured shaft of a diameter d larger than the nominal one of Δl value.

  20. Plastic Deformations of Measured Object Surface in Contact with Undeformable Surface of Measuring Tool

    Science.gov (United States)

    Kowalik, Marek; Rucki, Mirosław; Paszta, Piotr; Gołębski, Rafał

    2016-10-01

    Measuring errors caused by deformation (flattening) of a measured object appear under the influence of pressure force and weight of the measured object. Plastic strain, arising at the contact of a measured object and an undeformable contact tip of a measuring device, can be calculated by applying the Hertz plastic solution and the hypothesis of plastic strain. In a small area of contact between two bodies pressing against one another with force F, there appears the so-called contact stress. It can sometime reach very high values, exceeding the yield point, even when the contact pressure is relatively small. In the present work, the authors describe a theoretical solution to the problem of plastic strain between two bodies. The derived relationships enable to calculate force F during measurements of a deformable object by means of an instrument with an undeformable, spherical measuring tip. By applying the τmax hypothesis, a solution was obtained for the force F in an inexplicit form. The theoretical solution was verified with the digital simulation and experimental measurement. With the FEM method, the limit length gage was modeled in interaction with the measured shaft of a diameter d larger than the nominal one of Δl value.

  1. Seawater desalination using renewable energy sources

    Energy Technology Data Exchange (ETDEWEB)

    Kalogirou, S.A. [Higher Technical Inst., Nicosia, Cyprus (Greece). Dept. of Mechanical Engineering

    2005-07-01

    The origin and continuation of mankind is based on water. Water is one of the most abundant resources on earth, covering three-fourths of the planet's surface. However, about 97% of the earth's water is salt water in the oceans, and a tiny 3% is fresh water. This small percentage of the earth's water - which supplies most of human and animal needs - exists in ground water, lakes and rivers. The only nearly inexhaustible sources of water are the oceans, which, however, are of high salinity. It would be feasible to address the water-shortage problem with seawater desalination; however, the separation of salts from seawater requires large amounts of energy which, when produced from fossil fuels, can cause harm to the environment. Therefore, there is a need to employ environmentally-friendly energy sources in order to desalinate seawater. After a historical introduction into desalination, this paper covers a large variety of systems used to convert seawater into fresh water suitable for human use. It also covers a variety of systems, which can be used to harness renewable energy sources; these include solar collectors, photovoltaics, solar ponds and geothermal energy. Both direct and indirect collection systems are included. The representative example of direct collection systems is the solar still. Indirect collection systems employ two sub-systems; one for the collection of renewable energy and one for desalination. For this purpose, standard renewable energy and desalination systems are most often employed. Only industrially-tested desalination systems are included in this paper and they comprise the phase change processes, which include the multistage flash, multiple effect boiling and vapour compression and membrane processes, which include reverse osmosis and electrodialysis. The paper also includes a review of various systems that use renewable energy sources for desalination. Finally, some general guidelines are given for selection of

  2. Interferometric method for measuring high velocities of diffuse surfaces

    International Nuclear Information System (INIS)

    Maron, Y.

    1978-01-01

    An interferometric method for measuring the displacement of diffuse surfaces moving with velocities of a few microsecond is presented. The method utilizes the interference between two light beams reflected from a constant area of the moving surface at two different angles. It enables the detection of high rate velocity variations. Light source of a fairly low temporal coherence and power around 100mW is needed. (author)

  3. An instrument for the measurement of road surface reflection properties

    DEFF Research Database (Denmark)

    Corell, Dennis Dan; Sørensen, K.

    2017-01-01

    Road surface reflection data in the form of standard r-tables serve as input for design calculations of road lighting installations on traffic roads. However, in several countries the use of the standard r-tables has not been verified by measurement in a long period of time, while the types of road...... surfaces in use have changed - for instance to road surface types with less noise from wheel passages. Because of this, a co-operation between the road administrations of the Nordic countries (abbreviated NMF) decided to construct a portable instrument to be used on selections of traffic roads within...

  4. Experimental Method for Measuring Dust Load on Surfaces in Rooms

    DEFF Research Database (Denmark)

    Lengweiler, Philip; Nielsen, Peter V.; Moser, Alfred

    , there is a need for better understanding of the mechanism of dust deposition and resuspension. With the presented experimental setup, the dust load on surfaces in a channel can be measured as a function of the environmental and surface conditions and the type of particles under controlled laboratory conditions.......A new experimental setup to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airborne dust concentration considerably. As a basis for developing methods to eliminate dust-related problems in rooms...

  5. Reporting central tendencies of chamber measured surface emission and oxidation.

    Science.gov (United States)

    Abichou, Tarek; Clark, Jeremy; Chanton, Jeffery

    2011-05-01

    Methane emissions, concentrations, and oxidation were measured on eleven MSW landfills in eleven states spanning from California to Pennsylvania during the three year study. The flux measurements were performed using a static chamber technique. Initial concentration samples were collected immediately after placement of the flux chamber. Oxidation of the emitted methane was evaluated using stable isotope techniques. When reporting overall surface emissions and percent oxidation for a landfill cover, central tendencies are typically used to report "averages" of the collected data. The objective of this study was to determine the best way to determine and report central tendencies. Results showed that 89% of the data sets of collected surface flux have lognormal distributions, 83% of the surface concentration data sets are also lognormal. Sixty seven percent (67%) of the isotope measured percent oxidation data sets are normally distributed. The distribution of data for all eleven landfills provides insight of the central tendencies of emissions, concentrations, and percent oxidation. When reporting the "average" measurement for both flux and concentration data collected at the surface of a landfill, statistical analyses provided insight supporting the use of the geometric mean. But the arithmetic mean can accurately represent the percent oxidation, as measured with the stable isotope technique. We examined correlations between surface CH(4) emissions and surface air CH(4) concentrations. Correlation of the concentration and flux values using the geometric mean proved to be a good fit (R(2)=0.86), indicating that surface scans are a good way of identifying locations of high emissions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Inverse analysis of inner surface temperature history from outer surface temperature measurement of a pipe

    International Nuclear Information System (INIS)

    Kubo, S; Ioka, S; Onchi, S; Matsumoto, Y

    2010-01-01

    When slug flow runs through a pipe, nonuniform and time-varying thermal stresses develop and there is a possibility that thermal fatigue occurs. Therefore it is necessary to know the temperature distributions and the stress distributions in the pipe for the integrity assessment of the pipe. It is, however, difficult to measure the inner surface temperature directly. Therefore establishment of the estimation method of the temperature history on inner surface of pipe is needed. As a basic study on the estimation method of the temperature history on the inner surface of a pipe with slug flow, this paper presents an estimation method of the temperature on the inner surface of a plate from the temperature on the outer surface. The relationship between the temperature history on the outer surface and the inner surface is obtained analytically. Using the results of the mathematical analysis, the inverse analysis method of the inner surface temperature history estimation from the outer surface temperature history is proposed. It is found that the inner surface temperature history can be estimated from the outer surface temperature history by applying the inverse analysis method, even when it is expressed by the multiple frequency components.

  7. Adsorption of uranium in seawater

    International Nuclear Information System (INIS)

    Kobuke, Yoshiaki

    1988-01-01

    Among the metal resources dissolved in seawater, elements which are considered to bring the additional value by extraction are listed. At present, the industrialization of the extraction of rare components is not expected except sodium and magnesium. In order to make it feasible, the scientific principle for solving extremely low concentration and the competition of coexisting ions, and the establishment of the peculiar molecule resognition of respective metal ions are necessary first of all. Based on these, the support of the engineering technique for handling enormous quantity of seawater is necessary. In this report, the recent research and development of the extraction of uranium in seawater are described, and the problems to be solved are pointed out. In the oxidizing atmosphere on the earth, uranium exists in the form of uranium dioxide, but under the existence of carbonic acid, stable carbonic acid complex is formed, and it was confirmed that this is uniformly dissolved in the sea worldwide. The concentration is as very low as 3.3 ppb, but the total amount is about 4 billion tons. The general problems in the extraction of uranium in seawater, the molecular design of the adsorbent for extracting uranium in seawater, amidoxime resin and the fibers, the search for the engineering techniques of extracting uranium in seawater, desorbing process and the adsorption system of fiber adsorbent are described. (Kako, I.)

  8. Intelligent sampling for the measurement of structured surfaces

    International Nuclear Information System (INIS)

    Wang, J; Jiang, X; Blunt, L A; Scott, P J; Leach, R K

    2012-01-01

    Uniform sampling in metrology has known drawbacks such as coherent spectral aliasing and a lack of efficiency in terms of measuring time and data storage. The requirement for intelligent sampling strategies has been outlined over recent years, particularly where the measurement of structured surfaces is concerned. Most of the present research on intelligent sampling has focused on dimensional metrology using coordinate-measuring machines with little reported on the area of surface metrology. In the research reported here, potential intelligent sampling strategies for surface topography measurement of structured surfaces are investigated by using numerical simulation and experimental verification. The methods include the jittered uniform method, low-discrepancy pattern sampling and several adaptive methods which originate from computer graphics, coordinate metrology and previous research by the authors. By combining the use of advanced reconstruction methods and feature-based characterization techniques, the measurement performance of the sampling methods is studied using case studies. The advantages, stability and feasibility of these techniques for practical measurements are discussed. (paper)

  9. 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.

  10. Accuracy and reliability of three-dimensional surface reconstruction measurement

    International Nuclear Information System (INIS)

    Mizukami, Chikashi; Yamamoto, Etsuo; Ohmura, Masaki; Oiki, Hiroyuki; Tsuji, Jun; Muneta, Yuki; Tanabe, Makito; Hakuba, Nobuhiro; Azemoto, Syougo.

    1993-01-01

    We are using a new three-dimensional (3-D) surface reconstruction system to measure the temporal bones. This system offers the advantage of observation of the external aperture of the vestibular aqueduct and the porus acusticus internus in living subjects. However, its accuracy has not been confirmed. To investigate the accuracy of this new system, we measured the length of an in situ ceramic ossicular replacement prosthesis (CORP) of known length of 6.0 mm using 3-D surface reconstruction, conventional plain X-ray and polytomography. The CORP was scanned in the axial, sagittal and oblique directions. The mean measured length obtained with the 3-D surface reconstruction images was 5.94±0.21 on vertical scans, 5.91±0.27 on horizontal scans, and 6.01±0.25 on oblique scans. There were no significant differences among the measured lengths obtained in the three directions. Therefore, this 3-D surface reconstruction measurement system is considered to be reliable. Conversely, the mean measured length obtained by plain X-ray was 7.98±0.20, and by polytomography it was 7.94±0.23. These conventional methods have the inherent disadvantage of magnification of size which consequently requires correction. (author)

  11. An Isotope Dilution Method for High-frequency Measurements of Dissolved Inorganic Carbon concentration in the Surface Ocean

    Science.gov (United States)

    Huang, K.; Bender, M. L.; Wanninkhof, R. H.; Cassar, N.

    2013-12-01

    Dissolved inorganic carbon (DIC) is one of the most important species in the ocean carbon system. An autonomous system using isotope dilution as its core method has been developed to obtain high-frequency measurements of dissolved inorganic carbon (DIC) concentrations in the surface ocean. This system accurately mixes a seawater sample and a 13C-labeled sodium bicarbonate solution (spike). The mixed solution is then acidified and sent through a gas permeable membrane contactor. CO2 derived from DIC in the mixture is extracted by a CO2-free gas stream, and is sent to a cavity ring-down spectrometer to analyze its 13C/12C ratio. [DIC] of the seawater can then be derived from the measured 13C/12C, the known mixing ratio and the [DI13C] of the spike. The method has been tested under a wide [DIC] range (1800-2800 μmol/kg) in the laboratory. It has also been deployed on a cruise that surveyed ocean waters to the south of Florida. At a sampling resolution of 4 minutes (15 samples per hour), the relative standard deviation of DIC determined from the laboratory tests and the field deployment is ×0.07% and ×0.09%, respectively. The accuracy of the method is better than 0.1% except where [DIC] varies faster than 5 μmol/kg per minute. Based on the laboratory and field evaluations, we conclude that this method can provide accurate underway [DIC] measurements at high resolution in most oceanic regions. Schematic illustration of the work flow.

  12. Surface temperature measurement of plasma facing components in tokamaks

    International Nuclear Information System (INIS)

    Amiel, Stephane

    2014-01-01

    During this PhD, the challenges on the non-intrusive surface temperature measurements of metallic plasma facing components in tokamaks are reported. Indeed, a precise material emissivity value is needed for classical infrared methods and the environment contribution has to be known particularly for low emissivities materials. Although methods have been developed to overcome these issues, they have been implemented solely for dedicated experiments. In any case, none of these methods are suitable for surface temperature measurement in tokamaks.The active pyrometry introduced in this study allows surface temperature measurements independently of reflected flux and emissivities using pulsed and modulated photothermal effect. This method has been validated in laboratory on metallic materials with reflected fluxes for pulsed and modulated modes. This experimental validation is coupled with a surface temperature variation induced by photothermal effect and temporal signal evolvement modelling in order to optimize both the heating source characteristics and the data acquisition and treatment. The experimental results have been used to determine the application range in temperature and detection wavelengths. In this context, the design of an active pyrometry system on tokamak has been completed, based on a bicolor camera for a thermography application in metallic (or low emissivity) environment.The active pyrometry method introduced in this study is a complementary technique of classical infrared methods used for thermography in tokamak environment which allows performing local and 2D surface temperature measurements independently of reflected fluxes and emissivities. (author) [fr

  13. Distribution and temporal changes of lead in the surface seawater in the western Pacific and adjacent seas derived from coral skeletons

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Mayuri [Graduate School of Science, Tohoku University, Aramaki, Aoba, Sendai 980-8578 (Japan)]. E-mail: mayuri-inoue@aist.go.jp; Hata, Akiko [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Suzuki, Atsushi [Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central No. 7, 1-1-1 Higashi, Tsukuba 305-8567 (Japan); Nohara, Masato [Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central No. 7, 1-1-1 Higashi, Tsukuba 305-8567 (Japan); Shikazono, Naotatsu [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Yim, Wyss W.-S. [Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR (China); Hantoro, Wahyoe S. [Research and Development Centre for Geotechnology Indonesian Institute of Sciences Jl, Bandung (Indonesia); Donghuai, Sun [South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301 (China); Kawahata, Hodaka [Graduate School of Science, Tohoku University, Aramaki, Aoba, Sendai 980-8578 (Japan); Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology, Tsukuba Central No. 7, 1-1-1 Higashi, Tsukuba 305-8567 (Japan); Ocean Research Institute, University of Tokyo, 1-15-1 Minamidai, Nakano-ku, Tokyo 164-8639 (Japan)

    2006-12-15

    We determined Pb contents together with Pb isotopic compositions in coral skeletons (Porites spp.) collected from the western Pacific and adjacent seas to examine distribution of Pb in sea surfaces. Temporal records of Pb were also investigated using coral skeletons from Hainan and Ogasawara Island, located in China and Japan, respectively. The spatial distribution of Pb showed a clear dilution pattern of Pb from Asian continent to the open ocean. Also the similar trend was found in the Java Sea from Jakarta to the offshore. In addition to the spatial distribution, Pb contents in Ogasawara coral have gradually increased during last 108 years. It may be attributed to Pb emission mainly from industrial activities in Asian countries. Hainan coral, which provided 10 years record of Pb, showed a remarkable decline around 1997 probably due to the partial introduction of unleaded gasoline in China. - Temporal and spatial variations of Pb in the western Pacific were studied using coral skeletons.

  14. Rapid and gradual modes of aerosol trace metal dissolution in seawater

    Directory of Open Access Journals (Sweden)

    Katherine Rose Marie Mackey

    2015-01-01

    Full Text Available Atmospheric deposition is a major source of trace metals in marine surface waters and supplies vital micronutrients to phytoplankton, yet measured aerosol trace metal solubility values are operationally defined and there are relatively few multi-element studies on aerosol-metal solubility in seawater. Here we measure the solubility of aluminum (Al, cadmium (Cd, cobalt (Co, copper (Cu, iron (Fe, manganese (Mn, nickel (Ni, lead (Pb, and zinc (Zn from natural aerosol samples in seawater over a 7 day period to (1 evaluate the role of extraction time in trace metal dissolution behavior and (2 explore how the individual dissolution patterns could influence biota. Dissolution behavior occurs over a continuum ranging from rapid dissolution, in which the majority of soluble metal dissolved immediately upon seawater exposure (Cd and Co in our samples, to gradual dissolution, where metals dissolved slowly over time (Zn, Mn, Cu, and Al in our samples. Additionally, dissolution affected by interactions with particles was observed in which a decline in soluble metal concentration over time occurred (Fe and Pb in our samples. Natural variability in aerosol chemistry between samples can cause metals to display different dissolution kinetics in different samples, and this was particularly evident for Ni, for which samples showed a broad range of dissolution rates. The elemental molar ratio of metals in the bulk aerosols was 23,189Fe: 22,651Al: 445Mn: 348Zn: 71Cu: 48Ni: 23Pb: 9Co: 1Cd, whereas the seawater soluble molar ratio after 7 days of leaching was 11Fe: 620Al: 205Mn: 240Zn: 20Cu: 14Ni: 9Pb: 2Co: 1Cd. The different kinetics and ratios of aerosol metal dissolution have implications for phytoplankton nutrition, and highlight the need for unified extraction protocols that simulate aerosol metal dissolution in the surface ocean.

  15. Direct measurement of Cu surface self-diffusion on a checked surface

    International Nuclear Information System (INIS)

    Cousty, Jacques; Peix, Roger; Perraillon, Bernard.

    1976-01-01

    A radiotracer technique ( 64 Cu) was developed to measure surface diffusion on copper surfaces of total impurity concentration not exceeding some 10 -3 monolayers. The apparatus used consists of a slow electron diffraction device, an Auger analysis spectrometer (CMA), an ion gun and an evaporation device assembled in an ultra-vacuum chamber holding a residual pressure below 10 -10 Torr. A sample handler enables the surface studied to be positioned in front of each of these instruments. During the diffusion treatment the chemical composition of the surface is checked intermittently, and afterwards the spread of the deposit is measured outside the ultravacuum chamber. Slices several microns thick are removed and dissolved separately in dishes containing HNO 3 . The activity is then measured with a flow counter [fr

  16. Evaluation of Satellite-Based Surface Energy Budget Products with Surface Measurements Over the Great Lakes

    Science.gov (United States)

    Wang, H.; Loeb, N. G.; Lenters, J. D.; Spence, C.; Blanken, P.

    2017-12-01

    Earth's climate is fundamentally driven by the global energy balance. While Earth's energy budget at the top-of-atmosphere (TOA) is well understood, satellite-based estimates of the global mean surface energy budget yield an imbalance of 15-20 Wm-2. The data products used to infer the components of the surface energy budget are often based upon physical or empirical models and ancillary input data sets of varying quality. In order to make progress, comparisons between satellite-based estimates of the surface energy budget components and direct surface measurements are critically needed. This study evaluates surface radiative fluxes from NASA CERES EBAF and surface turbulent heat fluxes from OAFLUX by comparing them with surface station measurements from the Great Lakes Evaporation Network (GLEN). The GLEN measurements are collected using instruments on lighthouses in the Great Lakes, and include surface evaporation measurement via eddy covariance technique. The evaluation is performed for 3 offshore and 1 nearshore Great Lakes sites. We highlight results for Stannard Rock in Lake Superior, which is the farthest lighthouse from shore ( 40km from the nearest land). Relative to the GLEN observations, the OAFLUX underestimates latent heat flux by 12 Wm-2 (19 Wm-2) at Stannard Rock (4-station average), in part due to its weaker near surface wind speed, and overestimates sensible heat flux by 12 Wm-2 (6 Wm-2), which is partly contributed by its colder surface air temperature. The CERES EBAF-Surface overestimates the surface downward all-sky shortwave (longwave) flux by 8 Wm-2 (7 Wm-2) at Stannard Rock, and is comparable to the 4-station average. As a result, the surface estimated using EBAF-Surface and OAFLUX receives 16 Wm-2 (13 Wm-2) more than the GLEN observations at Stannard Rock (4-station average). The above surface energy flux differences will be further discussed based on a comparison between the input data sets used in the satellite-based estimates and

  17. Effects of dissolved species on radiolysis of diluted seawater

    International Nuclear Information System (INIS)

    Hata, Kuniki; Hanawa, Satoshi; Kasahara, Shigeki; Motooka, Takafumi; Tsukada, Takashi; Muroya, Yusa; Yamashita, Shinichi; Katsumura, Yosuke

    2014-01-01

    Fukushima Daiichi Nuclear Power Plants (NPPs) experienced seawater injection into the cores and fuel pools as an emergent measure after the accident. After the accident, retained water has been continuously desalinized, and subsequently the concentration of chloride ion (Cl - ) has been kept at a lower level these days. These ions in seawater are known to affect water radiolysis, which causes the production of radiolytic products, such as hydrogen peroxide (H 2 O 2 ), molecular hydrogen (H 2 ) and molecular oxygen (O 2 ). However, the effects of dissolved ions relating seawater on the production of the stable radiolytic products are not well understood in the diluted seawater. To understand of the production behavior in diluted seawater under radiation, radiolysis calculations were carried out. Production of H 2 is effectively suppressed by diluting by up to vol10%. The concentrations of oxidants (H 2 O 2 and O 2 ) are also suppressed by dilution of dissolved species. The effect of oxidants on corrosion of materials is thought to be low when the seawater was diluted by less than 1 vol% by water. It is also shown that deaeration is one of the effective measure to suppress the concentrations of oxidants at a lower level for any dilution conditions. (author)

  18. Mercury distribution in seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system.

    Science.gov (United States)

    Liu, Xiyao; Sun, Lumin; Yuan, Dongxing; Yin, Liqian; Chen, Jinsheng; Liu, Yaoxing; Liu, Chengyu; Liang, Ying; Lin, Fangfang

    2011-09-01

    More and more coal-fired power plants equipped with seawater flue gas desulfurization systems have been built in coastal areas. They release large amount of mercury (Hg)-containing waste seawater into the adjacent seas. However, very limited impact studies have been carried out. Our research targeted the distribution of Hg in the seawater, sediment, biota, and atmosphere, and its environmental transportation. Seawater samples were collected from five sites: 1, sea areas adjacent to the power plant; 2, near discharge outlets; 3, the aeration pool of the power plant; and 4 and 5, two reference sites. The total gaseous Hg was determined in situ with a Tekran 2537B. Analyses of total Hg (TM) followed the USEPA methods. In most part of the study area, TM concentrations were close to the reference values and Hg transfer from the seawater into the sediment and biota was not obvious. However, in the aeration pool and near the waste discharge outlets, atmospheric and surface seawater concentrations of TM were much higher, compared with those at a reference site. The concentration ranges of total gaseous Hg and TM in seawater were 3.83-8.60 ng/m(3) and 79.0-198 ng/L near the discharge outlets, 7.23-13.5 ng/m(3) and 186-616 ng/L in the aeration pool, and 2.98-4.06 ng/m(3) and 0.47-1.87 ng/L at a reference point. This study suggested that the Hg in the flue gas desulfurization waste seawater was not only transported and diluted with sea currents, but also could possibly be transferred into the atmosphere from the aeration pool and from the discharge outlets.

  19. Measuring surface flow velocity with smartphones: potential for citizen observatories

    Science.gov (United States)

    Weijs, Steven V.; Chen, Zichong; Brauchli, Tristan; Huwald, Hendrik

    2014-05-01

    Stream flow velocity is an important variable for discharge estimation and research on sediment dynamics. Given the influence of the latter on rating curves (stage-discharge relations), and the relative scarcity of direct streamflow measurements, surface velocity measurements can offer important information for, e.g., flood warning, hydropower, and hydrological science and engineering in general. With the growing amount of sensing and computing power in the hands of more outdoorsy individuals, and the advances in image processing techniques, there is now a tremendous potential to obtain hydrologically relevant data from motivated citizens. This is the main focus of the interdisciplinary "WeSenseIt" project, a citizen observatory of water. In this subproject, we investigate the feasibility of stream flow surface velocity measurements from movie clips taken by (smartphone-) cameras. First results from movie-clip derived velocity information will be shown and compared to reference measurements.

  20. Topography measurements for determining the decay factors in surface replication

    International Nuclear Information System (INIS)

    Song, J; Zheng, A; Vorburger, T V; Rubert, P

    2008-01-01

    The electro-forming technique is used at National Institute of Standards and Technology (NIST) for the production of standard reference material (SRM) 2461 standard casings to support nationwide ballistics measurement traceability and measurement quality control in the US. In order to ensure that the SRM casings are produced with virtually the same surface topography, it is necessary to test the decay factors of the replication process. Twenty-six replica casings are replicated from the same master casing for the decay factor tests. The NIST topography measurement system is used for measurements and correlations of surface topography. The topography decays are quantified by the cross-correlation function maximum CCF max . Based on the test, it is expected that 256 SRM casings can be replicated from the same master with CCF max values higher than 95%

  1. Measurement of surface crack length using image processing technology

    International Nuclear Information System (INIS)

    Nahm, Seung Hoon; Kim, Si Cheon; Kim, Yong Il; Ryu, Dae Hyun

    2001-01-01

    The development of a new experimental method is required to easily observe the growth behavior of fatigue cracks. To satisfy the requirement, an image processing technique was introduced to fatigue testing. The length of surface fatigue crack could be successfully measured by the image processing system. At first, the image data of cracks were stored into the computer while the cyclic loading was interrupted. After testing, crack length was determined using image processing software which was developed by ourselves. Block matching method was applied to the detection of surface fatigue cracks. By comparing the data measured by image processing system with the data measured by manual measurement with a microscope, the effectiveness of the image processing system was established. If the proposed method is used to monitor and observe the crack growth behavior automatically, the time and efforts for fatigue test could be dramatically reduced

  2. Two-pulse rapid remote surface contamination measurement.

    Energy Technology Data Exchange (ETDEWEB)

    Headrick, Jeffrey M.; Kulp, Thomas J.; Bisson, Scott E.; Reichardt, Thomas A.; Farrow, Roger L.

    2010-11-01

    This project demonstrated the feasibility of a 'pump-probe' optical detection method for standoff sensing of chemicals on surfaces. Such a measurement uses two optical pulses - one to remove the analyte (or a fragment of it) from the surface and the second to sense the removed material. As a particular example, this project targeted photofragmentation laser-induced fluorescence (PF-LIF) to detect of surface deposits of low-volatility chemical warfare agents (LVAs). Feasibility was demonstrated for four agent surrogates on eight realistic surfaces. Its sensitivity was established for measurements on concrete and aluminum. Extrapolations were made to demonstrate relevance to the needs of outside users. Several aspects of the surface PF-LIF physical mechanism were investigated and compared to that of vapor-phase measurements. The use of PF-LIF as a rapid screening tool to 'cue' more specific sensors was recommended. Its sensitivity was compared to that of Raman spectroscopy, which is both a potential 'confirmer' of PF-LIF 'hits' and is also a competing screening technology.

  3. Electric field vector measurements in a surface ionization wave discharge

    International Nuclear Information System (INIS)

    Goldberg, Benjamin M; Adamovich, Igor V; Lempert, Walter R; Böhm, Patrick S; Czarnetzki, Uwe

    2015-01-01

    This work presents the results of time-resolved electric field vector measurements in a short pulse duration (60 ns full width at half maximum), surface ionization wave discharge in hydrogen using a picosecond four-wave mixing technique. Electric field vector components are measured separately, using pump and Stokes beams linearly polarized in the horizontal and vertical planes, and a polarizer placed in front of the infrared detector. The time-resolved electric field vector is measured at three different locations across the discharge gap, and for three different heights above the alumina ceramic dielectric surface, ∼100, 600, and 1100 μm (total of nine different locations). The results show that after breakdown, the discharge develops as an ionization wave propagating along the dielectric surface at an average speed of 1 mm ns −1 . The surface ionization wave forms near the high voltage electrode, close to the dielectric surface (∼100 μm). The wave front is characterized by significant overshoot of both vertical and horizontal electric field vector components. Behind the wave front, the vertical field component is rapidly reduced. As the wave propagates along the dielectric surface, it also extends further away from the dielectric surface, up to ∼1 mm near the grounded electrode. The horizontal field component behind the wave front remains quite significant, to sustain the electron current toward the high voltage electrode. After the wave reaches the grounded electrode, the horizontal field component experiences a secondary rise in the quasi-dc discharge, where it sustains the current along the near-surface plasma sheet. The measurement results indicate presence of a cathode layer formed near the grounded electrode with significant cathode voltage fall, ≈3 kV, due to high current density in the discharge. The peak reduced electric field in the surface ionization wave is 85–95 Td, consistent with dc breakdown field estimated from the Paschen

  4. Surface Roughness Measurement on a Wing Aircraft by Speckle Correlation

    Directory of Open Access Journals (Sweden)

    Alberto Barrientos

    2013-09-01

    Full Text Available The study of the damage of aeronautical materials is important because it may change the microscopic surface structure profiles. The modification of geometrical surface properties can cause small instabilities and then a displacement of the boundary layer. One of the irregularities we can often find is surface roughness. Due to an increase of roughness and other effects, there may be extra momentum losses in the boundary layer and a modification in the parasite drag. In this paper we present a speckle method for measuring the surface roughness on an actual unmanned aircraft wing. The results show an inhomogeneous roughness distribution on the wing, as expected according to the anisotropic influence of the winds over the entire wing geometry. A calculation of the uncertainty of the technique is given.

  5. Surface roughness measurement on a wing aircraft by speckle correlation.

    Science.gov (United States)

    Salazar, Félix; Barrientos, Alberto

    2013-09-05

    The study of the damage of aeronautical materials is important because it may change the microscopic surface structure profiles. The modification of geometrical surface properties can cause small instabilities and then a displacement of the boundary layer. One of the irregularities we can often find is surface roughness. Due to an increase of roughness and other effects, there may be extra momentum losses in the boundary layer and a modification in the parasite drag. In this paper we present a speckle method for measuring the surface roughness on an actual unmanned aircraft wing. The results show an inhomogeneous roughness distribution on the wing, as expected according to the anisotropic influence of the winds over the entire wing geometry. A calculation of the uncertainty of the technique is given.

  6. Surface photovoltage measurements and finite element modeling of SAW devices.

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, Christine

    2012-03-01

    Over the course of a Summer 2011 internship with the MEMS department of Sandia National Laboratories, work was completed on two major projects. The first and main project of the summer involved taking surface photovoltage measurements for silicon samples, and using these measurements to determine surface recombination velocities and minority carrier diffusion lengths of the materials. The SPV method was used to fill gaps in the knowledge of material parameters that had not been determined successfully by other characterization methods. The second project involved creating a 2D finite element model of a surface acoustic wave device. A basic form of the model with the expected impedance response curve was completed, and the model is ready to be further developed for analysis of MEMS photonic resonator devices.

  7. Design parameters for measurements of local catalytic activity on surfaces

    DEFF Research Database (Denmark)

    Johansson, Martin; Johannessen, Tue; Jørgensen, Jan Hoffmann

    2006-01-01

    Computational fluid dynamics in combination with experiments is used to characterize a gas sampling device for measurements of the local catalytic activity on surfaces. The device basically consists of a quartz capillary mounted concentrically inside an aluminum tube. Reactant gas is blown toward...... the catalytic surface through the annulus between the tubes, and the gas is sampled close to the surface by the capillary. The influence of various design parameters on the lateral resolution and sensitivity of the measurements is investigated. It is found that the cuter diameter of the annulus sets the upper......, the limits of the range in reaction rate, which can be Studied are estimated. (c) 2005 Elsevier B.V. All rights reserved....

  8. Acoustics and Surface Pressure Measurements from Tandem Cylinder Configurations

    Science.gov (United States)

    Hutcheson, Florence V.; Brooks, Thomas F.; Lockard, David P.; Choudhari, Meelan M.; Stead, Daniel J.

    2014-01-01

    Acoustic and unsteady surface pressure measurements from two cylinders in tandem configurations were acquired to study the effect of spacing, surface trip and freestream velocity on the radiated noise. The Reynolds number ranged from 1.15x10(exp 5) to 2.17x10(exp 5), and the cylinder spacing varied between 1.435 and 3.7 cylinder diameters. The acoustic and surface pressure spectral characteristics associated with the different flow regimes produced by the cylinders' wake interference were identified. The dependence of the Strouhal number, peak Sound Pressure Level and spanwise coherence on cylinder spacing and flow velocity was examined. Directivity measurements were performed to determine how well the dipole assumption for the radiation of vortex shedding noise holds for the largest and smallest cylinder spacing tested.

  9. Freeform surface measurement and characterisation using a toolmakers microscope

    International Nuclear Information System (INIS)

    Wong, Francis Seung-yin; Chauh, Kong-Bieng; Venuvinod, Patri K

    2014-01-01

    Current freeform surface (FFS) characterization systems mainly cover aspects related to computer-aided design/manufacture (CAD/CAM). This paper describes a new approach that extends into computer-aided inspection (CAI).The following novel features are addressed: - ◼ Feature recognition and extraction from surface data; - ◼ Characterisation of properties of the surface's M and N vectors at individual vertex; - ◼ Development of a measuring plan using a toolmakers microscope for the inspection of the FFS; - ◼ Inspection of the actual FFS produced by CNC milling; - ◼ Verification of the measurement results and comparison with the CAD design data; Tests have shown that the deviations between the CAI and CAD data were within the estimated uncertainty limits

  10. Drinking water in Cuba and seawater desalination

    International Nuclear Information System (INIS)

    Meneses-Ruiz, E.; Turtos-Carbonell, L.M.; Oviedo-Rivero, I.

    2004-01-01

    The lack of drinking water has become a problem at world level because, in many places, supplies are very limited and, in other places, their reserves have been drained. At the present time there are estimated to be around two thousand million people that don't have drinking water for several reasons, such as drought, contamination and the presence of saline waters not suitable for human consumption. Because of the human need for water, they have always taken residence in areas where the supply was guaranteed, sometimes impeding the exploitation of other areas that can be economically very interesting. However, this resource is usually very close and in abundance in the form of seawater but its salinity makes it unusable for many basic requirements. Humanity has been forced, therefore, to take into consideration the possibilities of the economic treatment of seawater. Cuba has regions where the supplies of drinking water are scarce and others where the lack of this resource limits economic exploitation. The present work is approached with regard to the situation of hydro resources in Cuba, it includes: a description of the main hydrographic basins of the country; the contamination levels of the waters and the measures for mitigation; analysis of the supplies and demand for drinking water and its quality; regulatory aspects. The state of seawater desalination in Cuba is also included and the possibility of its realisation using nuclear energy and the advantages that this would bring is evaluated. (author)

  11. Drinking water in Cuba and seawater desalination

    Energy Technology Data Exchange (ETDEWEB)

    Meneses-Ruiz, E. [CUBAENERGIA, Playa, Havana (Cuba)]. E-mail: emeneses@cien.energia.inf.cu; Turtos-Carbonell, L.M.; Oviedo-Rivero, I. [CUBAENERGIA, Playa, Havana (Cuba)

    2004-07-01

    The lack of drinking water has become a problem at world level because, in many places, supplies are very limited and, in other places, their reserves have been drained. At the present time there are estimated to be around two thousand million people that don't have drinking water for several reasons, such as drought, contamination and the presence of saline waters not suitable for human consumption. Because of the human need for water, they have always taken residence in areas where the supply was guaranteed, sometimes impeding the exploitation of other areas that can be economically very interesting. However, this resource is usually very close and in abundance in the form of seawater but its salinity makes it unusable for many basic requirements. Humanity has been forced, therefore, to take into consideration the possibilities of the economic treatment of seawater. Cuba has regions where the supplies of drinking water are scarce and others where the lack of this resource limits economic exploitation. The present work is approached with regard to the situation of hydro resources in Cuba, it includes: a description of the main hydrographic basins of the country; the contamination levels of the waters and the measures for mitigation; analysis of the supplies and demand for drinking water and its quality; regulatory aspects. The state of seawater desalination in Cuba is also included and the possibility of its realisation using nuclear energy and the advantages that this would bring is evaluated. (author)

  12. Development of measurement standards for verifying functional performance of surface texture measuring instruments

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, A [Life and Industrial Product Development Department Olympus Corporation, 2951 Ishikawa-machi, Hachiouji-shi, Tokyo (Japan); Suzuki, H [Industrial Marketing and Planning Department Olympus Corporation, Shinjyuku Monolith, 3-1 Nishi-Shinjyuku 2-chome, Tokyo (Japan); Yanagi, K, E-mail: a_fujii@ot.olympus.co.jp [Department of Mechanical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka-machi, Nagaoka-shi, Niigata (Japan)

    2011-08-19

    A new measurement standard is proposed for verifying overall functional performance of surface texture measuring instruments. Its surface is composed of sinusoidal surface waveforms of chirp signals along horizontal cross sections of the material measure. One of the notable features is that the amplitude of each cycle in the chirp signal form is geometrically modulated so that the maximum slope is kept constant. The maximum slope of the chirp-like signal is gradually decreased according to movement in the lateral direction. We fabricated the measurement standard by FIB processing, and it was calibrated by AFM. We tried to evaluate the functional performance of Laser Scanning Microscope by this standard in terms of amplitude response with varying slope angles. As a result, it was concluded that the proposed standard can easily evaluate the performance of surface texture measuring instruments.

  13. Silicon surface barrier detectors used for liquid hydrogen density measurement

    Science.gov (United States)

    James, D. T.; Milam, J. K.; Winslett, H. B.

    1968-01-01

    Multichannel system employing a radioisotope radiation source, strontium-90, radiation detector, and a silicon surface barrier detector, measures the local density of liquid hydrogen at various levels in a storage tank. The instrument contains electronic equipment for collecting the density information, and a data handling system for processing this information.

  14. An instrument for the measurement of road surface reflection properties

    DEFF Research Database (Denmark)

    Corell, Dennis Dan; Sørensen, K.

    2017-01-01

    Road surface reflection data in the form of standard r-tables serve as input for design calculations of road lighting installations on traffic roads. However, in several countries the use of the standard r-tables has not been verified by measurement in a long period of time, while the types of road...

  15. Seasonal levels of the Vibrio predator Bacteriovorax in Atlantic, Pacific and Gulf Coast Seawater

    Science.gov (United States)

    Bacteriovorax were quantified in US Atlantic, Gulf and Pacific seawater to determine baseline levels of these predatory bacteria and possible seasonal fluctuations in levels. Surface seawater was analyzed monthly for 1 year from Kailua-Kona, Hawaii; the Gulf Coast of Alabama; and four sites along t...

  16. A new approach of surface flux measurements using DTS

    Science.gov (United States)

    van Emmerik, T. H. M.; Wenker, K. J. R.; Rimmer, A.; de Jong, S. A. P.; Lechinsky, Y.; van de Giesen, N. C.

    2012-04-01

    Estimation of surface fluxes is a difficult task, especially over lakes. Determining latent heat flux (evaporation), sensible heat flux and ground heat flux involves measurements and (or calculations) of net radiation, air temperature, water temperature, wind speed and relative humidity. This research presents a new method to measure surface fluxes by means of Distributed Temperature Sensing (DTS). From 0.5 m above lake level to 1.5 m under lake level DTS was applied to measure temperature. Using a PVC hyperboloid construction, a floating standalone measuring device was developed. This new setup distinguished itself by the open construction, so it is almost insensitive to direct radiation. While most of the lake ground heat changes occur very close to the lake surface, most measuring methods only obtain rough results. With this construction it was possible to create a spiral shaped fiber-optic cable setup, with which a vertical spatial resolution of 0.02 m and a temporal resolution of 1 min was obtained. The new method was tested in the deep Lake Kinneret (Israel) from 6 October, 2011 to 11 October, 2011and in the shallow Lake Binaba (Ghana) from 24 October, 2011 to 28 October, 2011. This study shows that with the developed method it is possible to capture the energy fluxes within the top water layer with a high resolution. When the old low resolution method was compared with the new high resolution method, it could be concluded that the impact of the surface fluxes in the upper layer is high on the energy balance on a daily scale. During the measuring period it was possible to use the temperature measured by the DTS to determine the sensible heat flux, the latent heat flux and the ground heat flux of both lakes.

  17. Estimation of surface area and surface area measure of three-dimensional sets from digitizations

    DEFF Research Database (Denmark)

    Ziegel, Johanna; Kiderlen, Markus

    2010-01-01

    A local method for estimating surface area and surface area measure of three-dimensional objects from discrete binary images is presented. A weight is assigned to each 2 × 2 × 2 configuration of voxels and the total surface area of an object is given by summation of the local area contributions....... The method is based on an exact asymptotic result that holds for increasing resolution of the digitization. It states that the number of occurrences of a 2 ×  2 × 2 configuration is asymptotically proportional to an integral of its “h-function” with respect to the surface area measure of the object. We find...

  18. Step-height measurements on sand surfaces: A comparison between optical scanner and coordinate measuring machine

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, Seyed Alireza; Tiedje, Niels Skat

    2016-01-01

    the same routine to touch the different positions on the polygonised mesh. Each measurement was repeated 5 times. The results of step height measurements on sand surfaces showed a maximum error of ± 12 µm for CMM, while scanner shows only ± 4 µm. Generally speaking, optical step height values were measured...

  19. Recovery of uranium from seawater

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Takagi, Norio; Katoh, Shunsaku

    1995-01-01

    Present status of the development of chelating adsorbents for the recovery of uranium from seawater is outlined with emphasis on the research by the author. Uranium is estimated to exist as stable tri (carbonate) uranylate (6) ion in seawater in a very low concentration. The adsorbent for uranium from seawater in a very low concentration. The adsorbent for uranium from seawater should have high selectivity and affinity for uranium around pH 8. The required characteristics for uranium adsorbent are examined. Various chelating adsorbents have been proposed for the uranium adsorbent and their structures are discussed. Amidoxime type adsorbents have the highest adsorbing power for uranium among the adsorbents hitherto developed and fibrous amidoxime adsorbents are most promising for the practical application. Synthesis, structure and suitable shape of the amidoxime adsorbents are discussed. Uranium adsorption behavior and the amount of saturated adsorption are examined theoretically based on the complexation of an amidoxime monomer and the formula for the adsorption equiliburium is derived. The adsorption and recovery process for uranium from seawater is composed of adsorption, desorption, separation and concentration and finally, uranium is recovered as the yellow cake. A floating body mooring system is proposed by Nobukawa. (T.H.)

  20. Analysis of flame surface density measurements in turbulent premixed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Halter, Fabien [Institut PRISME, Universite d' Orleans, 45072 Orleans (France); Chauveau, Christian; Goekalp, Iskender [Institut de Combustion, Aerothermique, Reactivite et Environnement, Centre National de la Recherche Scientifique, 45071 Orleans (France); Veynante, Denis [Laboratoire E.M2.C, Centre National de la Recherche Scientifique, Ecole Centrale Paris, 92295 Chatenay-Malabry (France)

    2009-03-15

    In premixed turbulent combustion, reaction rates can be estimated from the flame surface density. This parameter, which measures the mean flame surface area available per unit volume, may be obtained from algebraic expressions or by solving a transport equation. In this study, detailed measurements were performed on a Bunsen-type burner fed with methane/air mixtures in order to determine the local flame surface density experimentally. This burner, located in a high-pressure combustion chamber, allows investigation of turbulent premixed flames under various flow, mixture, and pressure conditions. In the present work, equivalence ratio was varied from 0.6 to 0.8 and pressure from 0.1 to 0.9 MPa. Flame front visualizations by Mie scattering laser tomography are used to obtain experimental data on the instantaneous flame front dynamics. The exact equation given by Pope is used to obtain flame surface density maps for different flame conditions. Some assumptions are made in order to access three-dimensional information from our two-dimensional experiments. Two different methodologies are proposed and tested in term of global mass balance (what enters compared to what is burned). The detailed experimental flame surface data provided for the first time in this work should progressively allow improvement of turbulent premixed flame modeling approaches. (author)

  1. NOTE: Surface dose extrapolation measurements with radiographic film

    Science.gov (United States)

    Butson, Martin J.; Cheung, Tsang; Yu, Peter K. N.; Currie, Michael

    2004-07-01

    Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields. An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate two-dimensional map of surface dose if required. Results have shown that the surface percentage dose can be estimated within ±3% of parallel plate ionization chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10 cm, 20 cm and 30 cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. The corresponding parallel plate ionization chamber measurements are 16%, 27% and 37%, respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size.

  2. Key techniques for vision measurement of 3D object surface

    Science.gov (United States)

    Yang, Huachao; Zhang, Shubi; Guo, Guangli; Liu, Chao; Yu, Ruipeng

    2006-11-01

    Digital close-range photogrammetry system and machine vision are widely used in production control, quality inspection. The main aim is to provide accurate 3D objects or reconstruction of an object surface and give an expression to an object shape. First, the key techniques of camera calibration and target image positioning for 3D object surface vision measurement were briefly reviewed and analyzed in this paper. Then, an innovative and effect method for precise space coordinates measurements was proposed. Test research proved that the thought and methods we proposed about image segmentation, detection and positioning of circular marks were effective and valid. A propriety weight value for adding parameters, control points and orientation elements in bundle adjustment with self-calibration are advantageous to gaining high accuracy of space coordinates. The RMS error of check points is less than +/-1 mm, which can meet the requirement in industrial measurement with high accuracy.

  3. Combined surface acoustic wave and surface plasmon resonance measurement of collagen and fibrinogen layer physical properties

    Directory of Open Access Journals (Sweden)

    J.-M. Friedt

    2016-12-01

    Full Text Available We use an instrument combining optical (surface plasmon resonance and acoustic (Love mode surface acoustic wave device real-time measurements on a same surface for the identification of water content in collagen and fibrinogen protein layers. After calibration of the surface acoustic wave device sensitivity by copper electrodeposition and surfactant adsorption, the bound mass and its physical properties – density and optical index – are extracted from the complementary measurement techniques and lead to thickness and water ratio values compatible with the observed signal shifts. Such results are especially usefully for protein layers with a high water content as shown here for collagen on an hydrophobic surface. We obtain the following results: collagen layers include 70±20% water and are 16±3 to 19±3 nm thick for bulk concentrations ranging from 30 to 300 μg/ml. Fibrinogen layers include 50±10% water for layer thicknesses in the 6±1.5 to 13±2 nm range when the bulk concentration is in the 46 to 460 μg/ml range. Keywords: surface acoustic wave, surface plasmon resonance, collagen, fibrinogen, density, thickness

  4. Youngimonas vesicularis gen. nov., sp. nov., of the family Rhodobacteraceae, isolated from surface seawater, reclassification of Donghicola xiamenensis Tan et al. 2009 as Pseudodonghicola xiamenensis gen. nov., comb. nov. and emended description of the genus Donghicola Yoon et al. 2007.

    Science.gov (United States)

    Hameed, Asif; Shahina, Mariyam; Lin, Shih-Yao; Nakayan, Phanit; Liu, You-Cheng; Lai, Wei-An; Hsu, Yi-Han

    2014-08-01

    A Gram-staining-negative, non-pigmented, strictly aerobic, rod-shaped, non-spore-forming, non-motile bacterium, devoid of bacteriochlorophyll, designated strain CC-AMW-E(T), was isolated from surface seawater off the coast at Kending, Taiwan. Strain CC-AMW-E(T) shared 95.7 and 93.9% 16S rRNA gene sequence similarity, respectively, with the type strains of the type species of the genera Donghicola (Donghicola eburneus SW-277(T)) and Roseovarius (Roseovarius tolerans EL-172(T)). The predominant (>75% of the total) fatty acid was summed feature 8 (C(18 : 1)ω6c and/or C(18 : 1)ω7c). The polar lipid profile included major amounts of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and an unidentified aminolipid. In addition, moderate amounts of an unidentified lipid and trace amounts of an unidentified phospholipid were detected. The DNA G+C content was 67.9 mol%. Ubiquinone Q-10 was the sole respiratory quinone. Based on its phylogenetic distinctiveness and distinguishing phenotypic characteristics (in particular its polar lipid pattern), we conclude that strain CC-AMW-E(T) represents a novel genus and species of the family Rhodobacteraceae, for which the name Youngimonas vesicularis gen. nov., sp. nov. is proposed. The type strain of Youngimonas vesicularis is CC-AMW-E(T) ( = JCM 18819(T) = BCRC 80549(T)). In addition, an emended description of the genus Donghicola Yoon et al. 2007 and the reclassification of Donghicola xiamenensis Tan et al. 2009 as Pseudodonghicola xiamenensis gen. nov., comb. nov. (type strain Y-2(T) = MCCC 1A00107(T) = LMG 24574(T) = CGMCC 1.7081(T)) are proposed. © 2014 IUMS.

  5. An experimental method for making spectral emittance and surface temperature measurements of opaque surfaces

    International Nuclear Information System (INIS)

    Moore, Travis J.; Jones, Matthew R.; Tree, Dale R.; Daniel Maynes, R.; Baxter, Larry L.

    2011-01-01

    An experimental procedure has been developed to make spectral emittance and temperature measurements. The spectral emittance of an object is calculated using measurements of the spectral emissive power and of the surface temperature of the object obtained using a Fourier transform infrared (FTIR) spectrometer. A calibration procedure is described in detail which accounts for the temperature dependence of the detector. The methods used to extract the spectral emissive power and surface temperature from measured infrared spectra were validated using a blackbody radiator at known temperatures. The average error in the measured spectral emittance was 2.1% and the average difference between the temperature inferred from the recorded spectra and the temperature indicated on the blackbody radiator was 1.2%. The method was used to measure the spectral emittance of oxidized copper at various temperatures.

  6. Optical triangulation method for height measurements on water surfaces

    Science.gov (United States)

    Maas, Hans-Gerd; Hentschel, Bernd; Schreiber, Frank

    2003-01-01

    Optical triangulation methods based on a laser light sheet and a camera are frequently used as a surface measurement technique in a wide range of applications. They allow for the fast accurate determination of height profiles, based on relatively simple hardware and software configurations. Moreover, they can be implemented very efficiently and are especially suited for measurements on moving objects such as products on an assembly line. The study presented in the paper describes the adaptation of laser light sheet optical triangulation techniques to the task of water level profile measurements in hydromechanics experimental facilities. The properties of water surfaces necessitate several modifications of optical triangulation techniques to make them applicable: The mirror-like reflection properties of water surfaces form a contradiction to the assumption of diffuse reflection, on which standard light sheet triangulation techniques are based; this problem can be circumvented by using a diffuse reflecting projection plane to capture the mirror-like reflection of the laser line from the water surface. Due to the angle of incidence law, however, water surface tilts caused by waves will usually cause a strong degradation of the quality of the results when using reflected light; this effect can largely be compensated by processing max-store images derived from short image sequences rather than single images. These extensions of optical triangulation turned out to be crucial for the applicability of the method on water surfaces. Besides the theoretical concept and a sensitivity analysis of the method, a system configuration is outlined, and the results of a number of practical experiments are shown and discussed.

  7. A new surface resistance measurement method with ultrahigh sensitivity

    International Nuclear Information System (INIS)

    Liang, Changnian.

    1993-01-01

    A superconducting niobium triaxial cavity has been designed and fabricated to study residual surface resistance of planar superconducting materials. The edge of a 25.4 mm or larger diameter sample in the triaxial cavity is located outside the strong field region. Therefore, the edge effects and possible losses between the thin film and the substrate have been minimized, ensuring that induced RF losses are intrinsic to the test material. The fundamental resonant frequency of the cavity is the same as the working frequency of CEBAF cavities. The cavity has a compact size compared to its TE 011 counterpart, which makes it more sensitive to the sample's loss. For even higher sensitivity, a calorimetry method has been used to measure the RF losses on the superconducting sample. At 2 K, a 2 μK temperature change can be resolved by using carbon resistor sensors. The temperature distribution caused by RF heating is measured by 16 carbon composition resistor sensors. A 0.05 μW heating power can be detected as such a resolution, which translates to a surface resistance of 0.02 nΩ at a surface magnetic field of 52 Oe. This is the most sensitive device for surface resistance measurements to date. In addition, losses due to the indium seal, coupling probes, field emission sites other than the sample, and all of the high field resonator surface, are excluded in the measurement. Surface resistance of both niobium and high-Tc superconducting thin films has been measured. A low R s of 35.2 μΩ was measured for a 25.4 mm diameter YBa 2 Cu 3 O 7 thin film at 1.5 GHz and at 2 K. The measurement result is the first result for a large area epitaxially grown thin film sample at such a low RF frequency. The abrupt disappearance of multipacting between two parallel plates has been observed and monitored with the 16 temperature mapping sensors. Field emission or some field dependent anomalous RF losses on the niobium plate have also been observed

  8. Water Surface and Velocity Measurement-River and Flume

    Directory of Open Access Journals (Sweden)

    J. H. Chandler

    2014-06-01

    Full Text Available Understanding the flow of water in natural watercourses has become increasingly important as climate change increases the incidence of extreme rainfall events which cause flooding. Vegetation in rivers and streams reduce water conveyance and natural vegetation plays a critical role in flood events which needs to be understood more fully. A funded project at Loughborough University is therefore examining the influence of vegetation upon water flow, requiring measurement of both the 3-D water surface and flow velocities. Experimental work therefore requires the measurement of water surface morphology and velocity (i.e. speed and direction in a controlled laboratory environment using a flume but also needs to be adaptable to work in a real river. Measuring the 3D topographic characteristics and velocity field of a flowing water surface is difficult and the purpose of this paper is to describe recent experimental work to achieve this. After reviewing past work in this area, the use of close range digital photogrammetry for capturing both the 3D water surface and surface velocity is described. The selected approach uses either two or three synchronised digital SLR cameras in combination with PhotoModeler for data processing, a commercial close range photogrammetric package. One critical aspect is the selection and distribution of appropriate floating marker points, which are critical if automated and appropriate measurement methods are to be used. Two distinct targeting approaches are available: either large and distinct specific floating markers or some fine material capable of providing appropriate texture. Initial work described in this paper uses specific marker points, which also provide the potential measuring surface velocity. The paper demonstrates that a high degree of measurement and marking automation is possible in a flume environment, where lighting influences can be highly controlled. When applied to a real river it is apparent that

  9. Wave-Driven Porewater-Seawater Exchange in Sandy Coastal Sediments

    Science.gov (United States)

    Hebert, A. B.; Sansone, F. J.; Pawlak, G.

    2005-12-01

    Shelf systems with permeable (sandy) seabeds are a focus of considerable recent interest. However, there is currently only a poor understanding of the exact interplay between physical forcing, sediment-seawater fluxes, sediment alteration, and pelagic ecosystem response in these dynamic systems. A series of laboratory experiments and field validations were performed to observe porewater-seawater mixing of a fluorescent dye tracer (fluorescein) using a fiber optic system in permeable sediments (~75% within 125-250 μm grain size, ~0.3 porosity) under enhanced hydraulic conditions. Preliminary laboratory results suggested the fiber optic probe was effective at measuring wave-enhanced tracer mixing. Mixing of dye, driven by paddle-generated standing waves, was several orders of magnitude greater than molecular diffusion (3.96±0.9 x 10-4 versus 8.4±0.8 x 10-6 cm2 s-1, respectively). Similarly, this approach has been adapted to a field site on the south shore of Oahu, Hawaii (21.29° N, 157.87° W) utilizing in situ instrumentation at 10 m water depth. A single fiber optic probe was used as a first approach for sampling porewater mixing rates, although multiple probes will be used in field measurements commencing in fall, 2005. In addition, sediment surface and subsurface pressure data were collected simultaneously to measure the effects of surface waves on porewater mixing rates. This was the first step of a series of experiments that will be integrated into the Kilo Nalo nearshore reef observatory for the measurement of porewater/seawater mixing rates over a range of surface wave conditions.

  10. Seawater desalination with nuclear power

    International Nuclear Information System (INIS)

    2005-01-01

    Nuclear power helps reduce costs for energy-intensive processes such as seawater desalination. A new generation of innovative small and medium nuclear power plants could co-generate electricity and potable water from seawater, both safely and at competitive prices in today's market. The IAEA provides technical support to Member States facing water shortage problems, on assessing the viability of nuclear power in seawater desalination. The support, usually channelled through national Technical Cooperation (TC) projects, can take several forms, ranging from educational training and technical advice on feasibility studies to design and safety review of demonstration projects. The IAEA offers a software tool (DEEP) that can be used to evaluate the economics of the different desalination and heat source configurations, including nuclear and fossil options

  11. Simultaneous measurements of top surface and its underlying film surfaces in multilayer film structure.

    Science.gov (United States)

    Ghim, Young-Sik; Rhee, Hyug-Gyo; Davies, Angela

    2017-09-19

    With the growth of 3D packaging technology and the development of flexible, transparent electrodes, the use of multilayer thin-films is steadily increasing throughout high-tech industries including semiconductor, flat panel display, and solar photovoltaic industries. Also, this in turn leads to an increase in industrial demands for inspection of internal analysis. However, there still remain many technical limitations to overcome for measurement of the internal structure of the specimen without damage. In this paper, we propose an innovative optical inspection technique for simultaneous measurements of the surface and film thickness corresponding to each layer of multilayer film structures by computing the phase and reflectance over a wide range of wavelengths. For verification of our proposed method, the sample specimen of multilayer films was fabricated via photolithography process, and the surface profile and film thickness of each layer were measured by two different techniques of a stylus profilometer and an ellipsometer, respectively. Comparison results shows that our proposed technique enables simultaneous measurements of the top surface and its underlying film surfaces with high precision, which could not be measured by conventional non-destructive methods.

  12. A paired apatite and calcite clumped isotope thermometry approach to estimating Cambro-Ordovician seawater temperatures and isotopic composition

    Science.gov (United States)

    Bergmann, Kristin D.; Finnegan, Seth; Creel, Roger; Eiler, John M.; Hughes, Nigel C.; Popov, Leonid E.; Fischer, Woodward W.

    2018-03-01

    The secular increase in δ18O values of both calcitic and phosphatic marine fossils through early Phanerozoic time suggests either that (1) early Paleozoic surface temperatures were high, in excess of 40 °C (tropical MAT), (2) the δ18O value of seawater has increased by 7-8‰ VSMOW through Paleozoic time, or (3) diagenesis has altered secular trends in early Paleozoic samples. Carbonate clumped isotope analysis, in combination with petrographic and elemental analysis, can deconvolve fluid composition from temperature effects and therefore determine which of these hypotheses best explain the secular δ18O increase. Clumped isotope measurements of a suite of calcitic and phosphatic marine fossils from late Cambrian- to Middle-late Ordovician-aged strata-the first paired fossil study of its kind-document tropical sea surface temperatures near modern temperatures (26-38 °C) and seawater oxygen isotope ratios similar to today's ratios.

  13. Hydrologic Science and Satellite Measurements of Surface Water (Invited)

    Science.gov (United States)

    Alsdorf, D. E.; Mognard, N. M.; Lettenmaier, D. P.

    2010-12-01

    While significant advances continue to be made for satellite measurements of surface waters, important science and application opportunities remain. Examples include the following: (1) Our current methods of measuring floodwater dynamics are either sparsely distributed or temporally inadequate. As an example, flood depths are measured by using high water marks, which capture only the peak of the flood wave, not its temporal variability. (2) Discharge is well measured at individual points along stream networks using in-situ gauges, but these do not capture within-reach hydraulic variability such as the water surface slope changes on the rising and falling limbs of flood waves. (3) Just a 1.0 mm/day error in ET over the Congo Basin translates to a 35,000 m3/s discharge error. Knowing the discharge of the Congo River and its many tributaries should significantly improve our understanding of the water balance throughout the basin. The Congo is exemplary of many other basins around the globe. (4) Arctic hydrology is punctuated by millions of unmeasured lakes. Globally, there might be as many as 30 million lakes larger than a hectare. Storage changes in these lakes are nearly unknown, but in the Arctic such changes are likely an indication of global warming. (5) Well over 100 rivers cross international boundaries, yet the sharing of water data is poor. Overcoming this helps to better manage the entire river basin while also providing a better assessment of potential water related disasters. The Surface Water and Ocean Topography (SWOT, http://swot.jpl.nasa.gov/) mission is designed to meet these needs by providing global measurements of surface water hydrodynamics. SWOT will allow estimates of discharge in rivers wider than 100m (50m goal) and storage changes in water bodies larger than 250m by 250m (and likely as small as one hectare).

  14. Determination of trace metals in coastal seawater around Okinawa and its multielement profiling analysis

    International Nuclear Information System (INIS)

    Itoh, Akihide; Ishigaki, Teruyuki; Arakaki, Teruo; Yamada, Ayako; Yamaguchi, Mami; Kabe, Noriko

    2009-01-01

    In the present study, trace metals in coastal surface seawater around Okinawa were determined by inductively coupled plasma mass spectrometry (ICP-MS) with chelating disk preconcentration. As a result, the concentrations of V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb, and U were obtained in the range from 10 μgL -1 to 0.001 μgL -1 for 6 samples. In addition, multielement profiling analyses were carried out using analytical values obtained in order to elucidate the features of trace metals in each coastal sea area. For coastal surface seawater near an urban area, the analytical values for Zn, Cu, Mn, and Pb were higher by more than 10-fold the literature values for open-surface seawater, and those of Cd were also relatively high. Such a trend concerning the multi-element profile was almost similar to the literature values for coastal seawater of the main island of Japan. On the other hand, the analytical values of most elements for coastal surface seawater near a suburb area were in the range from 0.5 to 5 fold, compared to the literature values for open surface seawater. From multielement profiling analyses for nutrient type elements in marine chemistry, it was suggested that the concentrations of Zn and Cd in a coral sea area normalized to literature values for open surface-seawater were higher than those of Ni and Cu. (author)

  15. Magnetic flux surface measurements at the Wendelstein 7-X stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Otte, Matthias; Andreeva, Tamara; Biedermann, Christoph; Bozhenkov, Sergey; Geiger, Joachim; Sunn Pedersen, Thomas [Max-Planck-Institut fuer Plasmaphysik, Greifswald (Germany); Lazerson, Samuel [Princeton Plasma Physics Laboratory, Princeton (United States)

    2016-07-01

    Recently the first plasma operation phase of the Wendelstein 7-X stellarator has been started at IPP Greifswald. Wendelstein 7-X is an optimized stellarator with a complex superconducting magnet system consisting of 50 non-planar and 20 planar field coils and further 10 normal conducting control and 5 trim coils. The magnetic confinement and hence the expected plasma performance are decisively determined by the properties of the magnet system, especially by the existence and quality of the magnetic flux surfaces. Even small error fields may result in significant changes of the flux surface topology. Therefore, measurements of the vacuum magnetic flux surfaces have been performed before plasma operation. The first experimental results confirm the existence and quality of the flux surfaces to the full extend from low field up to the nominal field strength of B=2.5T. This includes the dedicated magnetic limiter configuration that is exclusively used for the first plasma operation. Furthermore, the measurements are indicating that the intrinsic error fields are within the tolerable range and can be controlled utilizing the trim coils as expected.

  16. Surface albedo measurements in Mexico City metropolitan area

    Energy Technology Data Exchange (ETDEWEB)

    Castro, T; Mar, B; Longoria, R; Ruiz Suarez, L. G [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico); Morales, L [Instituto de Geografia, UNAM, Mexico, D.F. (Mexico)

    2001-04-01

    Optical and thermal properties of soils are important input data for the meteorological and photochemical modules of air quality models. As development of these models increase on spatial resolution good albedo data become more important. In this paper measurements of surface albedo of UV (295-385 nm) and visible (450-550 nm) radiation are reported for different urban and rural surfaces in the vicinity of Mexico City. It was found for the downtown zone and average albedo value of 0.05 which is in very good agreement with reported values for urban surfaces. Our albedo values measured in UV region for grey cement and green grass are of 0.10 and 0.009, respectively, and quite similar to those found at the literature of 0.11 and 0.008 for those type of surfaces. [Spanish] Las propiedades opticas y termicas de suelos son datos importantes para los modulos meteorologicos y fotoquimicos de los modelos de calidad del aire. Conforme aumenta la resolucion espacial del modelo se vuelve mas importante contar con buenos datos de albedo. En este articulo se presentan mediciones de albedo superficial de radiacion Ultravioleta (295-385 nm) y visible (450-550 nm) para diferentes superficies urbanas. Los valores medidos de albedo en la region UV para cemento gris y pasto verde son de 0.10 y 0.009, respectivamente, y son muy similares a los reportados en la literatura, 0.11 y 0.008 para este tipo de superficies.

  17. Can atom-surface potential measurements test atomic structure models?

    Science.gov (United States)

    Lonij, Vincent P A; Klauss, Catherine E; Holmgren, William F; Cronin, Alexander D

    2011-06-30

    van der Waals (vdW) atom-surface potentials can be excellent benchmarks for atomic structure calculations. This is especially true if measurements are made with two different types of atoms interacting with the same surface sample. Here we show theoretically how ratios of vdW potential strengths (e.g., C₃(K)/C₃(Na)) depend sensitively on the properties of each atom, yet these ratios are relatively insensitive to properties of the surface. We discuss how C₃ ratios depend on atomic core electrons by using a two-oscillator model to represent the contribution from atomic valence electrons and core electrons separately. We explain why certain pairs of atoms are preferable to study for future experimental tests of atomic structure calculations. A well chosen pair of atoms (e.g., K and Na) will have a C₃ ratio that is insensitive to the permittivity of the surface, whereas a poorly chosen pair (e.g., K and He) will have a ratio of C₃ values that depends more strongly on the permittivity of the surface.

  18. Surface moisture measurement system hardware acceptance test report

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, G.A., Westinghouse Hanford

    1996-05-28

    This document summarizes the results of the hardware acceptance test for the Surface Moisture Measurement System (SMMS). This test verified that the mechanical and electrical features of the SMMS functioned as designed and that the unit is ready for field service. The bulk of hardware testing was performed at the 306E Facility in the 300 Area and the Fuels and Materials Examination Facility in the 400 Area. The SMMS was developed primarily in support of Tank Waste Remediation System (TWRS) Safety Programs for moisture measurement in organic and ferrocyanide watch list tanks.

  19. System design description for surface moisture measurement system (SMMS)

    Energy Technology Data Exchange (ETDEWEB)

    Vargo, G.F.

    1996-09-23

    The SMMS has been developed to measure moisture in the top few centimeters of tank waste. The SMMS development was initiated by the preliminary findings of SAR-033, and does not necessarily fulfill any established DQO. After the SAR-033 is released, if no significant changes are made, moisture measurements in the organic waste tanks will rapidly become a DQO. The SMMS was designed to be installed in any 4 inch or larger riser, and to allow maximum adjustability for riser lengths, and is used to deploy a sensor package on the waste surface within a 6 foot radius about the azimuth. The first sensor package will be a neutron probe.

  20. Surface moisture measurement system hardware acceptance test procedure

    International Nuclear Information System (INIS)

    Ritter, G.A.

    1996-01-01

    The purpose of this acceptance test procedure is to verify that the mechanical and electrical features of the Surface Moisture Measurement System are operating as designed and that the unit is ready for field service. This procedure will be used in conjunction with a software acceptance test procedure, which addresses testing of software and electrical features not addressed in this document. Hardware testing will be performed at the 306E Facility in the 300 Area and the Fuels and Materials Examination Facility in the 400 Area. These systems were developed primarily in support of Tank Waste Remediation System (TWRS) Safety Programs for moisture measurement in organic and ferrocyanide watch list tanks

  1. Actual evaporation estimation from infrared measurement of soil surface temperature

    Directory of Open Access Journals (Sweden)

    Davide Pognant

    2013-09-01

    Full Text Available Within the hydrological cycle, actual evaporation represents the second most important process in terms of volumes of water transported, second only to the precipitation phenomena. Several methods for the estimation of the Ea were proposed by researchers in scientific literature, but the estimation of the Ea from potential evapotranspiration often requires the knowledge of hard-to-find parameters (e.g.: vegetation morphology, vegetation cover, interception of rainfall by the canopy, evaporation from the canopy surface and uptake of water by plant roots and many existing database are characterized by missing or incomplete information that leads to a rough estimation of the actual evaporation amount. Starting from the above considerations, the aim of this study is to develop and validate a method for the estimation of the Ea based on two steps: i the potential evaporation estimation by using the meteorological data (i.e. Penman-Monteith; ii application of a correction factor based on the infrared soil surface temperature measurements. The dataset used in this study were collected during two measurement campaigns conducted both in a plain testing site (Grugliasco, Italy, and in a mountain South-East facing slope (Cogne, Italy. During those periods, hourly measurement of air temperature, wind speed, infrared surface temperature, soil heat flux, and soil water content were collected. Results from the dataset collected in the two testing sites show a good agreement between the proposed method and reference methods used for the Ea estimation.

  2. The role of probe oxide in local surface conductivity measurements

    Science.gov (United States)

    Barnett, C. J.; Kryvchenkova, O.; Wilson, L. S. J.; Maffeis, T. G. G.; Kalna, K.; Cobley, R. J.

    2015-05-01

    Local probe methods can be used to measure nanoscale surface conductivity, but some techniques including nanoscale four point probe rely on at least two of the probes forming the same low resistivity non-rectifying contact to the sample. Here, the role of probe shank oxide has been examined by carrying out contact and non-contact I V measurements on GaAs when the probe oxide has been controllably reduced, both experimentally and in simulation. In contact, the barrier height is pinned but the barrier shape changes with probe shank oxide dimensions. In non-contact measurements, the oxide modifies the electrostatic interaction inducing a quantum dot that alters the tunneling behavior. For both, the contact resistance change is dependent on polarity, which violates the assumption required for four point probe to remove probe contact resistance from the measured conductivity. This has implications for all nanoscale surface probe measurements and macroscopic four point probe, both in air and vacuum, where the role of probe oxide contamination is not well understood.

  3. Holographic otoscope for nanodisplacement measurements of surfaces under dynamic excitation.

    Science.gov (United States)

    Flores-Moreno, J M; Furlong, Cosme; Rosowski, John J; Harrington, Ellery; Cheng, Jeffrey T; Scarpino, C; Santoyo, F Mendoza

    2011-01-01

    We describe a novel holographic otoscope system for measuring nanodisplacements of objects subjected to dynamic excitation. Such measurements are necessary to quantify the mechanical deformation of surfaces in mechanics, acoustics, electronics, biology, and many other fields. In particular, we are interested in measuring the sound-induced motion of biological samples, such as an eardrum. Our holographic otoscope system consists of laser illumination delivery (IS), optical head (OH), and image processing computer (IP) systems. The IS delivers the object beam (OB) and the reference beam (RB) to the OH. The backscattered light coming from the object illuminated by the OB interferes with the RB at the camera sensor plane to be digitally recorded as a hologram. The hologram is processed by the IP using the Fresnel numerical reconstruction algorithm, where the focal plane can be selected freely. Our holographic otoscope system is currently deployed in a clinic, and is packaged in a custom design. It is mounted in a mechatronic positioning system to increase its maneuverability degrees to be conveniently positioned in front of the object to be measured. We present representative results highlighting the versatility of our system to measure deformations of complex elastic surfaces in the wavelength scale including a copper foil membrane and postmortem tympanic membrane. SCANNING 33: 342-352, 2011. © 2011 Wiley Periodicals, Inc. Copyright © 2011 Wiley Periodicals, Inc.

  4. Effect of calcium carbonate saturation of seawater on coral calcification

    Science.gov (United States)

    Gattuso, J.-P.; Frankignoulle, M.; Bourge, I.; Romaine, S.; Buddemeier, R.W.

    1998-01-01

    The carbonate chemistry of seawater is usually not considered to be an important factor influencing calcium-carbonate-precipitation by corals because surface seawater is supersaturated with respect to aragonite. Recent reports, however, suggest that it could play a major role in the evolution and biogeography of recent corals. We investigated the calcification rates of five colonies of the zooxanthellate coral Stylophora pistillata in synthetic seawater using the alkalinity anomaly technique. Changes in aragonite saturation from 98% to 585% were obtained by manipulating the calcium concentration. The results show a nonlinear increase in calcification rate as a function of aragonite saturation level. Calcification increases nearly 3-fold when aragonite saturation increases from 98% to 390%, i.e., close to the typical present saturation state of tropical seawater. There is no further increase of calcification at saturation values above this threshold. Preliminary data suggest that another coral species, Acropora sp., displays a similar behaviour. These experimental results suggest: (l) that the rate of calcification does not change significantly within the range of saturation levels corresponding to the last glacial-interglacial cycle, and (2) that it may decrease significantly in the future as a result of the decrease in the saturation level due to anthropogenic release of CO2 into the atmosphere. Experimental studies that control environmental conditions and seawater composition provide unique opportunities to unravel the response of corals to global environmental changes.

  5. Reconstruction of secular variation in seawater sulfate concentrations

    Science.gov (United States)

    Algeo, T. J.; Luo, G. M.; Song, H. Y.; Lyons, T. W.; Canfield, D. E.

    2014-09-01

    Long-term secular variation in seawater sulfate concentrations ([SO42-]SW) is of interest owing to its relationship to the oxygenation history of Earth's surface environment, but quantitative approaches to analysis of this variation remain underdeveloped. In this study, we develop two complementary approaches for assessment of the [SO42-] of ancient seawater and test their application to reconstructions of [SO42-]SW variation since the late Neoproterozoic Eon (that [SO42-]SW was low during the late Neoproterozoic (that have varied only slightly since 250 Ma. However, Phanerozoic seawater sulfate concentrations may have been drawn down to much lower levels (~ 1-4 mM) during short (≲ 2 Myr) intervals of the Cambrian, Early Triassic, Early Jurassic, and possibly other intervals as a consequence of widespread ocean anoxia, intense MSR, and pyrite burial. The procedures developed in this study offer potential for future high-resolution quantitative analyses of paleoseawater sulfate concentrations.

  6. Distributions of uranium adsorbed from seawater in spherical polyacrylamidoxime chelating resins

    International Nuclear Information System (INIS)

    Katoh, Shunsaku; Sugasaka, Kazuhiko; Hirotsu, Takahiro; Takai, Nobuharu; Itagaki, Takaharu; Ouchi, Hidenaga.

    1984-01-01

    Distributions of metals adsorbed from seawater in spherical polyacrylamidoxime chelating resins were measured by X-ray micro-analyzer. Distributions of uranium in adsorbents were different according to their gel structure or porosity. In the case of adsorbents with low swelling tendencies, uranium was adsorbed only in the superficial layers of the adsorbents. The amount of adsorbed uranium increased with increasing of contact time, but no uranium was detected in the center of adsorbent even after 331 days. Iron was adsorbed only in the surface layer. Magnesium was detected almost uniformly in all parts of adsorbent. Copper and zinc were detected very little. (author)

  7. Faraday's Law and Seawater Motion

    Science.gov (United States)

    De Luca, R.

    2010-01-01

    Using Faraday's law, one can illustrate how an electromotive force generator, directly utilizing seawater motion, works. The conceptual device proposed is rather simple in its components and can be built in any high school or college laboratory. The description of the way in which the device generates an electromotive force can be instructive not…

  8. Occurrence of seawater intrusion overshoot

    NARCIS (Netherlands)

    Morgan, L.K.; Bakker, M.; Werner, A.D.

    2015-01-01

    A number of numerical modeling studies of transient sea level rise (SLR) and seawater intrusion (SI) in flux-controlled aquifer systems have reported an overshoot phenomenon, whereby the freshwater-saltwater interface temporarily extends further inland than the eventual steady state position.

  9. Uranium from Seawater Program Review; Fuel Resources Uranium from Seawater Program DOE Office of Nuclear Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-07-01

    For nuclear energy to remain sustainable in the United States, economically viable sources of uranium beyond terrestrial ores must be developed. The goal of this program is to develop advanced adsorbents that can extract uranium from seawater at twice the capacity of the best adsorbent developed by researchers at the Japan Atomic Energy Agency (JAEA), 1.5 mg U/g adsorbent. A multidisciplinary team from Oak Ridge National Laboratory, Lawrence Berkeley National Laboratory, Pacific Northwest National Laboratory, and the University of Texas at Austin was assembled to address this challenging problem. Polymeric adsorbents, based on the radiation grafting of acrylonitrile and methacrylic acid onto high surface-area polyethylene fibers followed by conversion of the nitriles to amidoximes, have been developed. These poly(acrylamidoxime-co-methacrylic acid) fibers showed uranium adsorption capacities for the extraction of uranium from seawater that exceed 3 mg U/g adsorbent in testing at the Pacific Northwest National Laboratory Marine Sciences Laboratory. The essence of this novel technology lies in the unique high surface-area trunk material that considerably increases the grafting yield of functional groups without compromising its mechanical properties. This technology received an R&D100 Award in 2012. In addition, high surface area nanomaterial adsorbents are under development with the goal of increasing uranium adsorption capacity by taking advantage of the high surface areas and tunable porosity of carbon-based nanomaterials. Simultaneously, de novo structure-based computational design methods are being used to design more selective and stable ligands and the most promising candidates are being synthesized, tested and evaluated for incorporation onto a support matrix. Fundamental thermodynamic and kinetic studies are being carried out to improve the adsorption efficiency, the selectivity of uranium over other metals, and the stability of the adsorbents. Understanding

  10. The density-salinity relation of standard seawater

    Science.gov (United States)

    Schmidt, Hannes; Seitz, Steffen; Hassel, Egon; Wolf, Henning

    2018-01-01

    The determination of salinity by means of electrical conductivity relies on stable salt proportions in the North Atlantic Ocean, because standard seawater, which is required for salinometer calibration, is produced from water of the North Atlantic. To verify the long-term stability of the standard seawater composition, it was proposed to perform measurements of the standard seawater density. Since the density is sensitive to all salt components, a density measurement can detect any change in the composition. A conversion of the density values to salinity can be performed by means of a density-salinity relation. To use such a relation with a target uncertainty in salinity comparable to that in salinity obtained from conductivity measurements, a density measurement with an uncertainty of 2 g m-3 is mandatory. We present a new density-salinity relation based on such accurate density measurements. The substitution measurement method used is described and density corrections for uniform isotopic and chemical compositions are reported. The comparison of densities calculated using the new relation with those calculated using the present reference equations of state TEOS-10 suggests that the density accuracy of TEOS-10 (as well as that of EOS-80) has been overestimated, as the accuracy of some of its underlying density measurements had been overestimated. The new density-salinity relation may be used to verify the stable composition of standard seawater by means of routine density measurements.

  11. The evaporative fraction as a measure of surface energy partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, W.E. [Pacific Northwest Lab., Richland, WA (United States); Cuenca, R.H. [Oregon State Univ., Corvallis, OR (United States)

    1990-12-31

    The evaporative fraction is a ratio that expresses the proportion of turbulent flux energy over land surfaces devoted to evaporation and transpiration (evapotranspiration). It has been used to characterize the energy partition over land surfaces and has potential for inferring daily energy balance information based on mid-day remote sensing measurements. The HAPEX-MOBILHY program`s SAMER system provided surface energy balance data over a range of agricultural crops and soil types. The databases from this large-scale field experiment was analyzed for the purpose of studying the behavior and daylight stability of the evaporative fraction in both ideal and general meteorological conditions. Strong linear relations were found to exist between the mid-day evaporative fraction and the daylight mean evaporative fraction. Statistical tests however rejected the hypothesis that the two quantities were equal. The relations between the evaporative fraction and the surface soil moisture as well as soil moisture in the complete vegetation root zone were also explored.

  12. The evaporative fraction as a measure of surface energy partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, W.E. (Pacific Northwest Lab., Richland, WA (United States)); Cuenca, R.H. (Oregon State Univ., Corvallis, OR (United States))

    1990-01-01

    The evaporative fraction is a ratio that expresses the proportion of turbulent flux energy over land surfaces devoted to evaporation and transpiration (evapotranspiration). It has been used to characterize the energy partition over land surfaces and has potential for inferring daily energy balance information based on mid-day remote sensing measurements. The HAPEX-MOBILHY program's SAMER system provided surface energy balance data over a range of agricultural crops and soil types. The databases from this large-scale field experiment was analyzed for the purpose of studying the behavior and daylight stability of the evaporative fraction in both ideal and general meteorological conditions. Strong linear relations were found to exist between the mid-day evaporative fraction and the daylight mean evaporative fraction. Statistical tests however rejected the hypothesis that the two quantities were equal. The relations between the evaporative fraction and the surface soil moisture as well as soil moisture in the complete vegetation root zone were also explored.

  13. Capacitive deionization of seawater

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Fix, D.V.; Mack, G.V. [and others

    1995-10-01

    Capacitive deionization with carbon aerogel electrodes is an efficient and economical new process for removing salt and impurities from water. Carbon aerogel is a material that enables the successful purification of water because of its high surface area, optimum pore size, and low electrical resistivity. The electrodes are maintained at a potential difference of about one volt; ions are removed from the water by the imposed electrostatic field and retained on the electrode surface until the polarity is reversed. The capacitive deionization of water with a stack of carbon aerogel electrodes has been successfully demonstrated. The overall process offers advantages when compared to conventional water-purification methods, requiring neither pumps, membranes, distillation columns, nor thermal heaters. Consequently, the overall process is both robust and energy efficient. The current state of technology development, commercialization, and potential applications of this process are reviewed.

  14. Airborne Spectral Measurements of Surface-Atmosphere Anisotropy for Several Surfaces and Ecosystem over Southern Africa

    Science.gov (United States)

    Gatebe, C. K.; King, M. D.; Tsay, S.; Arnold, G. T.; Li, J. Y.

    2001-12-01

    The Cloud Absorption Radiometer (CAR) was flown aboard the University of Washington Convair CV-580 research aircraft and took measurements on 23 flights between August 15 and September 16. On 12 of those flights, BRF measurements were obtained over different natural surfaces and ecosystem in southern Africa. The BRF measurements were done to characterize surface anisotropy in support of SAFARI 2000 science objectives principally to validate products from NASA's EOS satellites, and to parameterize and validate BRF models. In this paper we present results of BRFs taken over two EOS validation sites: Skukuza tower, South Africa (25.0 oS, 31.5 oE) and Mongu tower, Zambia (15.4 oS, 23.3 oE). Additional sites are also considered and include, Maun tower, Botswana (20.0 oS, 23.5 oE), Sowa Pan, Botswana (20.6 oS, 26.2 oE) and Etosha Pan, Namibia (19.0 oS, 16.0 oE). The CAR is capable of measuring scattered light in fourteen spectral bands. The scan mirror, rotating at 100 rpm, directs the light into a Dall-Kirkham telescope where the beam is split into nine paths. Eight light beams pass through beam splitters, dichroics, and lenses to individual detectors (0.34-1.27 μ m), and finally are registered by eight data channels. They are sampled simultaneously and continuously. The ninth beam passes through a spinning filter wheel to an InSb detector cooled by a Stirling cycle cooler. Signals registered by the ninth data channel are selected from among six spectral channels (1.55-2.30 μ m). The filter wheel can either cycle through all six spectral bands at a prescribed interval (usually changing filter every fifth scan line), or lock onto any one of the six spectral bands and sample it continuously. To measure the BRF of the surface-atmosphere system, the University of Washington CV-580 had to bank at a comfortable roll angle of ~20 o and fly in a circle about 3 km in diameter above the surface for roughly two minutes. Replicated observations (multiple circular orbits) were

  15. Surface Current Measurements In Terra Nova Bay By Hf Radar

    Science.gov (United States)

    Flocco, D.; Falco, P.; Wadhams, P.; Spezie, G.

    We present the preliminary results of a field experiment carried out within frame- work of the CLIMA project of the Italian National Programme for Antarctic Research (PNRA) and in cooperation with the Scott Polar Research Institute of Cambridge. Dur- ing the second period (02/12/1999-23/01/2000) of the XV Italian expedition a coastal radar was used to characterize the current field in the area of Terra Nova Bay (TNB). One of the aims of the CLIMA (Climatic Long-term Interactions for the Mass balance in Antarctica) project is to determine the role of the polynya in the sea ice mass bal- ance, water structure and local climate. The OSCR-II experiment was planned in order to provide surface current measurements in the area of TNB polynya, one of the most important coastal polynya of the Ross Sea. OSCR (Ocean Surface Current Radar) is a shore based, remote sensing system designed to measure sea surface currents in coastal waters. Two radar sites (a master and a slave) provide with radial current mea- surements; data combined from both sites yield the total current vector. Unfortunately the master and slave stations did not work together throughout the whole period of the experiment. A description of the experiment and a discussion of the results, will be proposed.

  16. Surface measurement errors using commercial scanning white light interferometers

    International Nuclear Information System (INIS)

    Gao, F; Petzing, J; Coupland, J M; Leach, R K

    2008-01-01

    This paper examines the performance of commercial scanning white light interferometers in a range of measurement tasks. A step height artefact is used to investigate the response of the instruments at a discontinuity, while gratings with sinusoidal and rectangular profiles are used to investigate the effects of surface gradient and spatial frequency. Results are compared with measurements made with tapping mode atomic force microscopy and discrepancies are discussed with reference to error mechanisms put forward in the published literature. As expected, it is found that most instruments report errors when used in regions close to a discontinuity or those with a surface gradient that is large compared to the acceptance angle of the objective lens. Amongst other findings, however, we report systematic errors that are observed when the surface gradient is considerably smaller. Although these errors are typically less than the mean wavelength, they are significant compared to the vertical resolution of the instrument and indicate that current scanning white light interferometers should be used with some caution if sub-wavelength accuracy is required

  17. Surface measurement errors using commercial scanning white light interferometers

    Science.gov (United States)

    Gao, F.; Leach, R. K.; Petzing, J.; Coupland, J. M.

    2008-01-01

    This paper examines the performance of commercial scanning white light interferometers in a range of measurement tasks. A step height artefact is used to investigate the response of the instruments at a discontinuity, while gratings with sinusoidal and rectangular profiles are used to investigate the effects of surface gradient and spatial frequency. Results are compared with measurements made with tapping mode atomic force microscopy and discrepancies are discussed with reference to error mechanisms put forward in the published literature. As expected, it is found that most instruments report errors when used in regions close to a discontinuity or those with a surface gradient that is large compared to the acceptance angle of the objective lens. Amongst other findings, however, we report systematic errors that are observed when the surface gradient is considerably smaller. Although these errors are typically less than the mean wavelength, they are significant compared to the vertical resolution of the instrument and indicate that current scanning white light interferometers should be used with some caution if sub-wavelength accuracy is required.

  18. Surface temperature measurements of heterogeneous explosives by IR emission

    Energy Technology Data Exchange (ETDEWEB)

    Henson, B.F.; Funk, D.J.; Dickson, P.M.; Fugard, C.S.; Asay, B.W.

    1998-03-01

    The authors present measurements of the integrated IR emission (1--5 {micro}m) from both the heterogeneous explosive PBX 9501 and pure HMX at calibrated temperatures from 300 C to 2,500 C. The IR power emitted as a function of temperature is that expected of a black body, attenuated by a unique temperature independent constant which the authors report as the thermal emissivity. The authors have utilized this calibration of IR emission in measurements of the surface temperature from PBX 9501 subject to 1 GPa, two dimensional impact, and spontaneous ignition in unconfined cookoff. They demonstrate that the measurement of IR emission in this spectral region provides a temperature probe of sufficient sensitivity to resolve the thermal response from the solid explosive throughout the range of weak mechanical perturbation, prolonged heating to ignition, and combustion.

  19. Application of laser tracker technology for measuring optical surfaces

    Science.gov (United States)

    Zobrist, Tom L.

    The pages of this dissertation detail the development of an advanced metrology instrument for measuring large optical surfaces. The system is designed to accurately guide the fabrication of the Giant Magellan Telescope and future telescopes through loose-abrasive grinding. The instrument couples a commercial laser tracker with an advanced calibration technique and a set of external references to mitigate a number of error sources. The system is also required to work as a verification test for the GMT principal optical interferometric test of the polished mirror segment to corroborate the measurements in several low-order aberrations. A set of system performance goals were developed to ensure that the system will achieve these purposes. The design, analysis, calibration results, and measurement performance of the Laser Tracker Plus system are presented in this dissertation.

  20. Measurement of steep aspheric surfaces using an anamorphic probe

    International Nuclear Information System (INIS)

    Biswas, Amiya; Coupland, Jeremy

    2008-01-01

    Synthetic aperture interferometry has been previously proposed as a possible in-process method to measure aspheric form (R. Tomlinson, Appl. Opt.42, 701, 2003.APOPAI0003-693510.1364/AO.42.000701). Preliminary demonstration utilized a scanning probe consisting of a pair of bare single mode fibers to perform source and receive functions. It was found that this probe did not have sufficient numerical aperture (NA) to measure steep surfaces and that simply increasing the NA decreases the light gathering efficiency substantially. In this paper, we introduce supplementary optics to increase the NA, and the light gathering efficiency has been increased by adopting an anamorphic design. A spherical test optic of known form is measured to demonstrate the capability of the new probe design

  1. Measurement of steep aspheric surfaces using an anamorphic probe

    Science.gov (United States)

    Biswas, Amiya; Coupland, Jeremy

    2008-04-01

    Synthetic aperture interferometry has been previously proposed as a possible in-process method to measure aspheric form (R. Tomlinson, Appl. Opt.42, 701, 2003.APOPAI0003-693510.1364/AO.42.000701). Preliminary demonstration utilized a scanning probe consisting of a pair of bare single mode fibers to perform source and receive functions. It was found that this probe did not have sufficient numerical aperture (NA) to measure steep surfaces and that simply increasing the NA decreases the light gathering efficiency substantially. In this paper, we introduce supplementary optics to increase the NA, and the light gathering efficiency has been increased by adopting an anamorphic design. A spherical test optic of known form is measured to demonstrate the capability of the new probe design.

  2. Influence of glacial meltwater on global seawater δ234U

    Science.gov (United States)

    Arendt, Carli A.; Aciego, Sarah M.; Sims, Kenneth W. W.; Das, Sarah B.; Sheik, Cody; Stevenson, Emily I.

    2018-03-01

    We present the first published uranium-series measurements from modern Greenland Ice Sheet (GrIS) runoff and proximal seawater, and investigate the influence of glacial melt on global seawater δ234U over glacial-interglacial (g-ig) timescales. Climate reconstructions based on closed-system uranium-thorium (U/Th) dating of fossil corals assume U chemistry of seawater has remained stable over time despite notable fluctuations in major elemental compositions, concentrations, and isotopic compositions of global seawater on g-ig timescales. Deglacial processes increase weathering, significantly increasing U-series concentrations and changing the δ234U of glacial meltwater. Analyses of glacial discharge from GrIS outlet glaciers indicate that meltwater runoff has elevated U concentrations and differing 222Rn concentrations and δ234U compositions, likely due to variations in subglacial residence time. Locations with high δ234U have the potential to increase proximal seawater δ234U. To better understand the impact of bulk glacial melt on global seawater δ234U over time, we use a simple box model to scale these processes to periods of extreme deglaciation. We account for U fluxes from the GrIS, Antarctica, and large Northern Hemisphere Continental Ice Sheets, and assess sensitivity by varying melt volumes, duration and U flux input rates based on modern subglacial water U concentrations and compositions. All scenarios support the hypothesis that global seawater δ234U has varied by more than 1‰ through time as a function of predictable perturbations in continental U fluxes during g-ig periods.

  3. Estimating regional methane surface fluxes: the relative importance of surface and GOSAT mole fraction measurements

    Directory of Open Access Journals (Sweden)

    A. Fraser

    2013-06-01

    Full Text Available We use an ensemble Kalman filter (EnKF, together with the GEOS-Chem chemistry transport model, to estimate regional monthly methane (CH4 fluxes for the period June 2009–December 2010 using proxy dry-air column-averaged mole fractions of methane (XCH4 from GOSAT (Greenhouse gases Observing SATellite and/or NOAA ESRL (Earth System Research Laboratory and CSIRO GASLAB (Global Atmospheric Sampling Laboratory CH4 surface mole fraction measurements. Global posterior estimates using GOSAT and/or surface measurements are between 510–516 Tg yr−1, which is less than, though within the uncertainty of, the prior global flux of 529 ± 25 Tg yr−1. We find larger differences between regional prior and posterior fluxes, with the largest changes in monthly emissions (75 Tg yr−1 occurring in Temperate Eurasia. In non-boreal regions the error reductions for inversions using the GOSAT data are at least three times larger (up to 45% than if only surface data are assimilated, a reflection of the greater spatial coverage of GOSAT, with the two exceptions of latitudes >60° associated with a data filter and over Europe where the surface network adequately describes fluxes on our model spatial and temporal grid. We use CarbonTracker and GEOS-Chem XCO2 model output to investigate model error on quantifying proxy GOSAT XCH4 (involving model XCO2 and inferring methane flux estimates from surface mole fraction data and show similar resulting fluxes, with differences reflecting initial differences in the proxy value. Using a series of observing system simulation experiments (OSSEs we characterize the posterior flux error introduced by non-uniform atmospheric sampling by GOSAT. We show that clear-sky measurements can theoretically reproduce fluxes within 10% of true values, with the exception of tropical regions where, due to a large seasonal cycle in the number of measurements because of clouds and aerosols, fluxes are within 15% of true fluxes. We evaluate our

  4. Measuring and interpreting X-ray fluorescence from planetary surfaces.

    Science.gov (United States)

    Owens, Alan; Beckhoff, Burkhard; Fraser, George; Kolbe, Michael; Krumrey, Michael; Mantero, Alfonso; Mantler, Michael; Peacock, Anthony; Pia, Maria-Grazia; Pullan, Derek; Schneider, Uwe G; Ulm, Gerhard

    2008-11-15

    As part of a comprehensive study of X-ray emission from planetary surfaces and in particular the planet Mercury, we have measured fluorescent radiation from a number of planetary analog rock samples using monochromatized synchrotron radiation provided by the BESSY II electron storage ring. The experiments were carried out using a purpose built X-ray fluorescence (XRF) spectrometer chamber developed by the Physikalisch-Technische Bundesanstalt, Germany's national metrology institute. The XRF instrumentation is absolutely calibrated and allows for reference-free quantitation of rock sample composition, taking into account secondary photon- and electron-induced enhancement effects. The fluorescence data, in turn, have been used to validate a planetary fluorescence simulation tool based on the GEANT4 transport code. This simulation can be used as a mission analysis tool to predict the time-dependent orbital XRF spectral distributions from planetary surfaces throughout the mapping phase.

  5. Enhancement of Extraction of Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sheikhly, Mohamad [Univ. of Maryland, College Park, MD (United States); Dietz, Travis [Univ. of Maryland, College Park, MD (United States); Tsinas, Zois [Univ. of Maryland, College Park, MD (United States); Tomaszewski, Claire [Univ. of Maryland, College Park, MD (United States); Pazos, Ileana M. [Univ. of Maryland, College Park, MD (United States); Nigliazzo, Olga [The Catholic Univ. of America, Washington, DC (United States); Li, Weixing [The Catholic Univ. of America, Washington, DC (United States); Adel-Hadadi, Mohamad [Univ. of Maryland, College Park, MD (United States); Barkatt, Aaron [Univ. of Palermo (Italy)

    2016-04-01

    Even at a concentration of 3 μg/L, the world’s oceans contain a thousand times more uranium than currently know terrestrial sources. In order to take advantage of this stockpile, methods and materials must be developed to extract it efficiently, a difficult task considering the very low concentration of the element and the competition for extraction by other atoms in seawater such as sodium, calcium, and vanadium. The majority of current research on methods to extract uranium from seawater are vertical explorations of the grafting of amidoxime ligand, which was originally discovered and promoted by Japanese studies in the late 1980s. Our study expands on this research horizontally by exploring the effectiveness of novel uranium extraction ligands grafted to the surface of polymer substrates using radiation. Through this expansion, a greater understanding of uranium binding chemistry and radiation grafting effects on polymers has been obtained. While amidoxime-functionalized fabrics have been shown to have the greatest extraction efficiency so far, they suffer from an extensive chemical processing step which involves treatment with powerful basic solutions. Not only does this add to the chemical waste produced in the extraction process and add to the method’s complexity, but it also significantly impacts the regenerability of the amidoxime fabric. The approach of this project has been to utilize alternative, commercially available monomers capable of extracting uranium and containing a carbon-carbon double bond to allow it to be grafted using radiation, specifically phosphate, oxalate, and azo monomers. The use of commercially available monomers and radiation grafting with electron beam or gamma irradiation will allow for an easily scalable fabrication process once the technology has been optimized. The need to develop a cheap and reliable method for extracting uranium from seawater is extremely valuable to energy independence and will extend the quantity of

  6. Enhancement of Extraction of Uranium from Seawater

    International Nuclear Information System (INIS)

    Al-Sheikhly, Mohamad; Dietz, Travis; Tsinas, Zois; Tomaszewski, Claire; Pazos, Ileana M.; Nigliazzo, Olga; Li, Weixing; Adel-Hadadi, Mohamad; Barkatt, Aaron

    2016-01-01

    Even at a concentration of 3 @@g/L, the world@@@s oceans contain a thousand times more uranium than currently know terrestrial sources. In order to take advantage of this stockpile, methods and materials must be developed to extract it efficiently, a difficult task considering the very low concentration of the element and the competition for extraction by other atoms in seawater such as sodium, calcium, and vanadium. The majority of current research on methods to extract uranium from seawater are vertical explorations of the grafting of amidoxime ligand, which was originally discovered and promoted by Japanese studies in the late 1980s. Our study expands on this research horizontally by exploring the effectiveness of novel uranium extraction ligands grafted to the surface of polymer substrates using radiation. Through this expansion, a greater understanding of uranium binding chemistry and radiation grafting effects on polymers has been obtained. While amidoxime-functionalized fabrics have been shown to have the greatest extraction efficiency so far, they suffer from an extensive chemical processing step which involves treatment with powerful basic solutions. Not only does this add to the chemical waste produced in the extraction process and add to the method@@@s complexity, but it also significantly impacts the regenerability of the amidoxime fabric. The approach of this project has been to utilize alternative, commercially available monomers capable of extracting uranium and containing a carbon-carbon double bond to allow it to be grafted using radiation, specifically phosphate, oxalate, and azo monomers. The use of commercially available monomers and radiation grafting with electron beam or gamma irradiation will allow for an easily scalable fabrication process once the technology has been optimized. The need to develop a cheap and reliable method for extracting uranium from seawater is extremely valuable to energy independence and will extend the quantity of

  7. Electrical properties of Titan's surface from Cassini RADAR scatterometer measurements

    Science.gov (United States)

    Wye, Lauren C.; Zebker, Howard A.; Ostro, Steven J.; West, Richard D.; Gim, Yonggyu; Lorenz, Ralph D.; The Cassini Radar Team

    2007-06-01

    albedo feature Shangri-La is best fit by a Hagfors model with a dielectric constant close to 2.4 and an rms slope near 9.5°. From the modeled backscatter curves, we find the average radar albedo in the same linear (SL) polarization to be near 0.34. We constrain the total-power albedo in order to compare the measurements with available groundbased radar results, which are typically obtained in both senses of circular polarization. We estimate an upper limit of 0.4 on the total-power albedo, a value that is significantly higher than the 0.21 total albedo value measured at 13 cm [Campbell, D., Black, G., Carter, L., Ostro, S., 2003. Science 302, 431-434]. This is consistent with a surface that has more small-scale structure and is thus more reflective at 2-cm than 13-cm. We compare results across overlapping observations and observe that the reduction and analysis are repeatable and consistent. We also confirm the strong correlations between radar and near-infrared images.

  8. Surface solar irradiance from SCIAMACHY measurements: algorithm and validation

    Directory of Open Access Journals (Sweden)

    P. Wang

    2011-05-01

    Full Text Available Broadband surface solar irradiances (SSI are, for the first time, derived from SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY satellite measurements. The retrieval algorithm, called FRESCO (Fast REtrieval Scheme for Clouds from the Oxygen A band SSI, is similar to the Heliosat method. In contrast to the standard Heliosat method, the cloud index is replaced by the effective cloud fraction derived from the FRESCO cloud algorithm. The MAGIC (Mesoscale Atmospheric Global Irradiance Code algorithm is used to calculate clear-sky SSI. The SCIAMACHY SSI product is validated against globally distributed BSRN (Baseline Surface Radiation Network measurements and compared with ISCCP-FD (International Satellite Cloud Climatology Project Flux Dataset surface shortwave downwelling fluxes (SDF. For one year of data in 2008, the mean difference between the instantaneous SCIAMACHY SSI and the hourly mean BSRN global irradiances is −4 W m−2 (−1 % with a standard deviation of 101 W m−2 (20 %. The mean difference between the globally monthly mean SCIAMACHY SSI and ISCCP-FD SDF is less than −12 W m−2 (−2 % for every month in 2006 and the standard deviation is 62 W m−2 (12 %. The correlation coefficient is 0.93 between SCIAMACHY SSI and BSRN global irradiances and is greater than 0.96 between SCIAMACHY SSI and ISCCP-FD SDF. The evaluation results suggest that the SCIAMACHY SSI product achieves similar mean bias error and root mean square error as the surface solar irradiances derived from polar orbiting satellites with higher spatial resolution.

  9. Airborne spectral measurements of surface-atmosphere anisotropy for several surfaces and ecosystems over southern Africa

    Science.gov (United States)

    Gatebe, Charles K.; King, Michael D.; Platnick, Steve; Arnold, G. Thomas; Vermote, Eric F.; Schmid, Beat

    2003-07-01

    The Cloud Absorption Radiometer (CAR) was flown aboard the University of Washington Convair CV-580 research aircraft during the Southern Africa Regional Science Initiative 2000 (SAFARI 2000) dry season campaign and obtained measurements of bidirectional reflectance distribution function (BRDF) for a variety of natural surfaces and ecosystems in southern Africa. To measure the BRDF of the surface-atmosphere system, the University of Washington CV-580 banked at a roll angle of ˜20° and flew circles about 3 km in diameter above the surface, taking approximately 2 min. Multiple circular orbits were acquired over selected surfaces so that average BRDFs could be acquired, smoothing out small-scale surface and atmospheric inhomogeneities. In this paper, we present results of BRDFs taken over two Earth Observing System (EOS) validation sites: Skukuza tower, South Africa (25.0°S, 31.5°E) and Mongu tower, Zambia (15.4°S, 23.3°E). Additional sites are discussed and include the Maun tower, Botswana (20.0°S, 23.6°E), Sua Pan, Botswana (20.6°S, 25.9°E), Etosha Pan, Namibia (19.0°S, 16.0°E), and marine stratocumulus clouds off the west coast of Namibia (20.5°S, 13.1°E). Results clearly show anisotropy in reflected solar radiation over the various surfaces types: savanna, salt pans, and cloud. The greatest anisotropy is observed over marine stratus clouds, which exhibit strong forward scattering as well as important water cloud scattering features such as the rainbow and glory. The BRDF over savanna is characterized by a distinct backscattering peak in the principal plane and shows directional and spectral variations. Over the pans, the BRDF is more enhanced in the backscattering plane than forward scattering plane and shows little directional variation.

  10. Development of analytical techniques of vanadium isotope in seawater

    Science.gov (United States)

    Huang, T.; Owens, J. D.; Sarafian, A.; Sen, I. S.; Huang, K. F.; Blusztajn, J.; Nielsen, S.

    2015-12-01

    Vanadium (V) is a transition metal with isotopes of 50V and 51V, and oxidation states of +2, +3, +4 and +5. The average concentration in seawater is 1.9 ppb, which results in a marine residence time of ~50 kyrs. Its various oxidation states make it a potential tool for investigating redox conditions in the ocean and sediments due to redox related changes in the valance state of vanadium. In turn, chemical equilibrium between different oxidation states of V will likely cause isotopic fractionation that can potentially be utilized to quantify past ocean redox states. In order to apply V isotopes as a paleo-redox tracer, it is required that we know the isotopic composition of seawater and the relation to marine sources and sinks of V. We developed a novel method for pre-concentrating V and measuring the isotope ratio in seawater samples. In our method, we used four ion exchange chromatography columns to separate vanadium from seawater matrix elements, in particular titanium and chromium, which both have an isobaric interference on 50V. The first column uses the NOBIAS resin, which effectively separates V and other transition metals from the majority of seawater matrix. Subsequent columns are identical to those utilized when separating V from silicate samples (Nielsen et al, Geostand. Geoanal. Res., 2011). The isotopic composition of the purified V is measured using a Thermo Scientific Neptune multiple collector inductively coupled plasma mass spectrometer (MC-ICP-MS) in medium resolution mode. This setup resolves all molecular interferences from masses 49, 50, 51, 52 and 53 including S-O species on mass 50. To test the new method, we spiked an open ocean seawater sample from the Bermuda Atlantic Time Series (BATS) station with 10-25 μg of Alfa Aesar vanadium solution, which has an isotopic composition of δ51V = 0 [where δ51V = 1000 × [(51V/50Vsample - 51V/50VAA)/51V/50VAA]. The average of six spiked samples is -0.03±0.19‰, which is within error of the true

  11. The Measurement and Interpretation of Surface Wave Group Arrival Times

    Science.gov (United States)

    Masters, G.; Kane, D.; Morrow, J.; Zhou, Y.; Tromp, J.

    2005-12-01

    We have recently developed an efficient technique for measuring the relative group arrival times of surface waves by using cross-correlation and cluster analysis of waveform envelope functions. Applying the analysis to minor arc Love and Rayleigh waves in the frequency band 7 to 35 mHz for all events over magnitude 5.5 results in a dataset of over 200,000 measurements at each frequency for long period Rayleigh waves (frequency less than 25 mHz) and about 100,000 measurements at the shorter periods. Analysis of transverse components results in about half as many Love wave measurements. Simple ray theory inversions of the relative arrival times for apparent group velocity produce maps which are accurate representations of the data (often over 90% variance reduction of the relative arrival times) and which show features strongly correlated with tectonics and crustal thickness. The apparent group velocity variations can be extremely large: 30% velocity variations for 20 mHz Rayleigh waves and 40% variations for 30 mHz Rayleigh waves and can have abrupt lateral changes. This raises the concern that non-ray theory effects could be important. Indeed, a recent analysis by Dahlen and Zhou (personal communication) suggests that the group arrival times should be a functions of both the group velocity AND the phase velocity. The simplest way to test the interpretation of the measurements is to perform the analysis on synthetic seismograms computed for a realistic model of the Earth. Here, we use the SEM with a model which incorporates realistic crust and mantle structure. We are currently computing synthetics for a suite of roughly 1000 events recorded globally that extend to a period of 18 seconds. We shall present the results of applying both ray-based and finite frequency inversions to the synthetic data as well as evaluating the effects of off path propagation at short periods using surface wave ray tracing.

  12. Non‐diluted seawater enhances nasal ciliary beat frequency and wound repair speed compared to diluted seawater and normal saline

    Science.gov (United States)

    Bonnomet, Arnaud; Luczka, Emilie; Coraux, Christelle

    2016-01-01

    Background The regulation of mucociliary clearance is a key part of the defense mechanisms developed by the airway epithelium. If a high aggregate quality of evidence shows the clinical effectiveness of nasal irrigation, there is a lack of studies showing the intrinsic role of the different irrigation solutions allowing such results. This study investigated the impact of solutions with different pH and ionic compositions, eg, normal saline, non‐diluted seawater and diluted seawater, on nasal mucosa functional parameters. Methods For this randomized, controlled, blinded, in vitro study, we used airway epithelial cells obtained from 13 nasal polyps explants to measure ciliary beat frequency (CBF) and epithelial wound repair speed (WRS) in response to 3 isotonic nasal irrigation solutions: (1) normal saline 0.9%; (2) non‐diluted seawater (Physiomer®); and (3) 30% diluted seawater (Stérimar). The results were compared to control (cell culture medium). Results Non‐diluted seawater enhanced the CBF and the WRS when compared to diluted seawater and to normal saline. When compared to the control, it significantly enhanced CBF and slightly, though nonsignificantly, improved the WRS. Interestingly, normal saline markedly reduced the number of epithelial cells and ciliated cells when compared to the control condition. Conclusion Our results suggest that the physicochemical features of the nasal wash solution is important because it determines the optimal conditions to enhance CBF and epithelial WRS thus preserving the respiratory mucosa in pathological conditions. Non‐diluted seawater obtains the best results on CBF and WRS vs normal saline showing a deleterious effect on epithelial cell function. PMID:27101776

  13. Non-diluted seawater enhances nasal ciliary beat frequency and wound repair speed compared to diluted seawater and normal saline.

    Science.gov (United States)

    Bonnomet, Arnaud; Luczka, Emilie; Coraux, Christelle; de Gabory, Ludovic

    2016-10-01

    The regulation of mucociliary clearance is a key part of the defense mechanisms developed by the airway epithelium. If a high aggregate quality of evidence shows the clinical effectiveness of nasal irrigation, there is a lack of studies showing the intrinsic role of the different irrigation solutions allowing such results. This study investigated the impact of solutions with different pH and ionic compositions, eg, normal saline, non-diluted seawater and diluted seawater, on nasal mucosa functional parameters. For this randomized, controlled, blinded, in vitro study, we used airway epithelial cells obtained from 13 nasal polyps explants to measure ciliary beat frequency (CBF) and epithelial wound repair speed (WRS) in response to 3 isotonic nasal irrigation solutions: (1) normal saline 0.9%; (2) non-diluted seawater (Physiomer®); and (3) 30% diluted seawater (Stérimar). The results were compared to control (cell culture medium). Non-diluted seawater enhanced the CBF and the WRS when compared to diluted seawater and to normal saline. When compared to the control, it significantly enhanced CBF and slightly, though nonsignificantly, improved the WRS. Interestingly, normal saline markedly reduced the number of epithelial cells and ciliated cells when compared to the control condition. Our results suggest that the physicochemical features of the nasal wash solution is important because it determines the optimal conditions to enhance CBF and epithelial WRS thus preserving the respiratory mucosa in pathological conditions. Non-diluted seawater obtains the best results on CBF and WRS vs normal saline showing a deleterious effect on epithelial cell function. © 2016 The Authors International Forum of Allergy & Rhinology, published by ARSAAOA, LLC.

  14. Measuring the surface roughness of geological rock surfaces in SAR data using fractal geometry

    Science.gov (United States)

    Ghafouri, Ali; Amini, Jalal; Dehmollaian, Mojtaba; Kavoosi, Mohammad Ali

    2017-05-01

    Determining surface morphology using synthetic aperture radar (SAR) data requires accurate topographic and microtopographic models. To distinguish different surface geometric patterns and to differentiate the formation of geological rock surfaces, it is necessary to model the smoothness and roughness of surfaces based on radar signal backscattering. Euclidean geometry is less able than fractal geometry to describe natural phenomena; however, in application to radar backscattering models, fractal geometry has never fully replaced Euclidean geometry. Using fractal geometry only, this paper attempts to improve the backscattering simulation generated by an Integral Equation Model to improve the description of geological rock surfaces. As the application of radar signal backscattering is a rarity in the domain of geology, the paper also discusses the efficiency of the method in improving the results of conventional geological mapping methods. The proposed method is applied to the Anaran geological formation (between Dehloran and Ilam in IRAN) using TerraSAR-X SAR data and in situ roughness measurements on pure sites with rough, intermediate, and smooth morphologies. This implementation shows fractal and diffractal behavior of geological morphologies under various conditions.

  15. Detection of crude oil emulsions in the Bering Sea by the analysis of seawater color

    Science.gov (United States)

    Salyuk, Pavel A.; Stepochkin, Igor E.; Sokolova, Ekaterina B.; Kachur, Vasiliy A.; Prokuda, Natalya A.

    2015-11-01

    The paper presents the analysis of uncertainties between observed remote sensed reflectance spectra of seawater, with crude oil emulsions and oil dissolved fractions, and modeled remote sensed reflectance spectra of seawater without oil calculated from the fluorometric measurements of chlorophyll-a and dissolved organic matter concentrations carried out in the layer under oil pollution.

  16. Rapid Determination of Technetium-99 in Large Volume Seawater Samples Using Sequential Injection Extraction Chromatographic Separation and ICP-MS Measurement

    DEFF Research Database (Denmark)

    Shi, Keliang; Qiao, Jixin; Wu, Wangsuo

    2012-01-01

    , and measurement of 99Tc by inductively coupled plasma mass spectrometry (ICP-MS). Chromatographic behaviors of technetium, molybdenum, and ruthenium were investigated, and the mechanism of adsorption and elution of TcO4– on a TEVA column using HNO3 was explored. The results show that not only NO3– but also...

  17. Effectiveness of KNIFC-PAN Resin in Absorbing Radiocesium in Seawater

    International Nuclear Information System (INIS)

    Nurrul Assyikeen Mohd Jaffary; Abdul Kadir Ishak; Zal Uyun Wan Mahmood; Wo, Y.M.; Norfaizal Mohamed; Mohd Tarmizi Ishak

    2016-01-01

    The effectiveness of KNiFC-PAN absorber, potassium-nickel hexacyanoferrate (II) (KNiFC) bound into modified polyacrylonitrile (PAN) have been tested for capability in absorbing radiocesium in seawater samples. The efficiency of the KNiFC-PAN were measured by the different activity of the radiocesium measured using Hyper Pure Germanium Detector (HPGe) in initial spiked seawater and eluent seawater after passed through 5 ml of KNiFC absorber. Study showed 87 % effectiveness of the KNiFC-PAN in absorbing radiocesium. Further study conducted to illustrate relation between spiked seawater and activity measured for 5 ml of KniFC passed through spiked seawater in packed column. This study suggested this relative 15L cubitainer method can be used to monitor the radiocesium in emergency situation for the fast and reliable result. (author)

  18. Surface water temperature data collected from data logger at 1 meter from pier at Leigh Marine Laboratory, Auckland, New Zealand from 2011-07-10 to 2014-12-19 (NCEI Accession 0127341)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seawater surface temperatures collected adjacent the Leigh Marine Laboratory. Hourly measurements are taken by means of an electronic data logger. The sensor is...

  19. Measurement of atmospheric surface layer turbulence using unmanned aerial vehicles

    Science.gov (United States)

    Bailey, Sean; Canter, Caleb

    2017-11-01

    We describe measurements of the turbulence within the atmospheric surface layer using highly instrumented and autonomous unmanned aerial vehicles (UAVs). Results from the CLOUDMAP measurement campaign in Stillwater Oklahoma are presented including turbulence statistics measured during the transition from stably stratified to convective conditions. The measurements were made using pre-fabricated fixed-wing remote-control aircraft adapted to fly autonomously and carry multi-hole pressure probes, pressure, temperature and humidity sensors. Two aircraft were flown simultaneously, with one flying a flight path intended to profile the boundary layer up to 100 m and the other flying at a constant fixed altitude of 50 m. The evolution of various turbulent statistics was determined from these flights, including Reynolds stresses, correlations, spectra and structure functions. These results were compared to those measured by a sonic anemometer located on a 7.5 m tower. This work was supported by the National Science Foundation through Grant #CBET-1351411 and by National Science Foundation award #1539070, Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics (CLOUDMAP).

  20. Speciation analysis of 129I in seawater by carrier-free AgI-AgCl coprecipitation and accelerator mass spectrometric measurement

    DEFF Research Database (Denmark)

    Luo, Maoyi; Hou, Xiaolin; He, Chaohui

    2013-01-01

    -2 and then separated by the same method as for iodide. Ag2SO3 in the coprecipitate was removed by washing with 3 mol/L HNO3 and the excess AgCl and AgBr was removed by use of diluted NH3, and finally a 1-3 mg precipitate was obtained for AMS measurement of 129I. The recovery of iodine species in the entire procedure...

  1. Reliability of surface EMG measurements from the suprahyoid muscle complex

    DEFF Research Database (Denmark)

    Kothari, Mohit; Stubbs, Peter William; Pedersen, Asger Roer

    2017-01-01

    of using the suprahyoid muscle complex (SMC) using surface electromyography (sEMG) to assess changes to neural pathways by determining the reliability of measurements in healthy participants over days. Methods: Seventeen healthy participants were recruited. Measurements were performed twice with one week...... between sessions. Single pulse (at 120% and 140% of the resting motor threshold (rMT)) and paired pulse (2 ms and 15 ms paired pulse) transcranial magnetic stimulation (TMS) were used to elicit MEPs in the SMC which were recorded using sEMG. Results: ≈50% of participants (range: 42%-58%; depending...... on stimulus type/intensity) had significantly different MEP values between day 1 and day 2 for single pulse and paired pulse TMS. A large stimulus artefact resulted in MEP responses that could not be assessed in four participants. Conclusions: The assessment of the SMC using sEMG following TMS was poorly...

  2. Measurement of Tritium Surface Distribution on TFTR Bumper Limiter Tiles

    International Nuclear Information System (INIS)

    Sugiyama, K.; Tanabe, T.; Skinner, C.H.; Gentile, C.A.

    2004-01-01

    The tritium surface distribution on graphite tiles used in the Tokamak Fusion Test Reactor (TFTR) bumper limiter and exposed to TFTR deuterium-tritium (D-T) discharges from 1993 to 1997 was measured by the Tritium Imaging Plate Technique (TIPT). The TFTR bumper limiter shows both re-/co-deposition and erosion. The tritium images for all tiles measured are strongly correlated with erosion and deposition patterns, and long-term tritium retention was found in the re-/co-depositions and flakes. The CFC tiles located at erosion dominated areas clearly showed their woven structure in their tritium images owing to different erosion yields between fibers and matrix. Significantly high tritium retention was observed on all sides of the erosion tiles, indicating carbon transport via repetition of local erosion/deposition cycles

  3. Measured ground-surface movements, Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Massey, B.L.

    1981-01-01

    The Cerro Prieto geothermal area in the Mexicali Valley, 30 kilometers southeast of Mexicali, Baja California, incurred slight deformation because of the extraction of hot water and steam, and probably, active tectonism. During 1977 to 1978, the US Geological Survey established and measured two networks of horizontal control in an effort to define both types of movement. These networks consisted of: (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from stations on an existing US Geological Survey crustal-strain network north of the international border; and (2) a local net tied to stations in the regional net and encompassing the present and planned geothermal production area. Electronic distance measuring instruments were used to measure the distances between stations in both networks in 1978, 1979 and 1981. Lines in the regional net averaged 25 km. in length and the standard deviation of an individual measurement is estimated to be approx. 0.3 part per million of line length. The local network was measured using different instrumentation and techniques. The average line length was about 5 km. and the standard deviation of an individual measurement approached 3 parts per million per line length. Ground-surface movements in the regional net, as measured by both the 1979 and 1981 resurveys, were small and did not exceed the noise level. The 1979 resurvey of the local net showed an apparent movement of 2 to 3 centimeters inward toward the center of the production area. This apparent movement was restricted to the general limits of the production area. The 1981 resurvey of the local net did not show increased movement attributable to fluid extraction.

  4. Measuring surface energy and evapotranspiration across Caribbean mangrove forests

    Science.gov (United States)

    Lagomasino, D.; Fatoyinbo, T. E.; Price, R.

    2014-12-01

    Coastal mangroves lose large amounts of water through evapotranspiration (ET) that can be equivalent to the amount of annual rainfall in certain years. Satellite remote sensing has been used to estimate surface energy and ET variability in many forested ecosystems, yet has been widely overlooked in mangrove forests. Using a combination of long-term datasets (30-year) acquired from the NASA Landsat 5 and 7 satellite databases, the present study investigated ET and surface energy balance variability between two mangrove forest sites in the Caribbean: 1) Everglades National Park (ENP; Florida, USA) and 2) Sian Ka'an Biosphere Reserve (SKBR; Quintana Roo, Mexico). A satellite-derived surface energy balance model was used to estimate ET in tall and scrub mangroves environments at ENP and SKBR. Results identified significant differences in soil heat flux measurements and ET between the tall and scrub mangrove environments. Scrub mangroves exhibited the highest soil heat flux coincident with the lowest biophysical indices (i.e., Fractional Vegetation Cover, Normalized Difference Vegetation Index, and Soil-Adjusted Vegetation Index) and ET rates. Mangrove damage and mortality was observed on the satellite images following strong tropical storms and associated with anthropogenic modifications and resulted in low values in spectral vegetation indices, higher soil heat flux, and higher ET. Recovery of the spectral characteristics, soil heat flux and ET was within 1-2 years following hurricane disturbance while, degradation caused by human disturbance persisted for many years. Remotely sensed ET of mangrove forests can provide estimates over a few decades and provide us with some understanding of how these environments respond to disturbances to the landscape in periods where no ground data exists or in locations that are difficult to access. Moreover, relationships between energy and water balance components developed for the coastal mangroves of Florida and Mexico could be

  5. Analytical calculation of muon intensities under deep sea-water

    Science.gov (United States)

    Inazawa, H.; Kobayakawa, K.

    1985-01-01

    The study of the energy loss of high energy muons through different materials, such as rock and sea-water can cast light on characteristics of lepton interactions. There are less ambiguities for the values of atomic number (Z) and mass number (A) in sea-water than in rock. Muon intensities should be measured as fundamental data and as background data for searching the fluxes of neutrino. The average range energy relation in sea-water is derived. The correction factors due to the range fluctuation is also computed. By applying these results, the intensities deep under sea are converted from a given muon energy spectra at sea-level. The spectra of conventional muons from eta, K decays have sec theta enhancement. The spectrum of prompt muons from charmed particles is almost isotropic. The effect of prompt muons is examined.

  6. Entrance surface dose measurements in mammography using thermoluminescence technique

    International Nuclear Information System (INIS)

    Rivera, T.; Vega C, H.R.; Manzanares A, E; Azorin, J.; Gonzalez, P.R.

    2007-01-01

    Full text: Of the various techniques that can be used for personnel dosimetry, thermoluminescence dosimetry (TLD) has emerged as a superior technique due to its manifold advantages over other methods of dose estimation. Various phosphors have been therefore investigated regarding their suitability for dosimetry. In this paper, a dosimetry system based on thermally stimulated luminescence (TSL) from zirconium oxide phosphors embedded in polytetrafluorethylene (ZrO 2 +PTFE) was developed for entrance surface doses (ES) measurements in mammography. Small ZrO 2 pellets of 5 mm in diameter and 0.8 mm in thickness were used. The reproducibility of measurements and linearity of ZrO 2 were also studied. The results were compared with those obtained from LiF:Mg,Cu,P usually used for the determination of absorbed dose in mammography. Measurements both per unit air kerma and In vivo were performed using a mammography unit model DMR (General Electric). The results showed that ZrO 2 TLDs can be used for the same X-ray dosimetry applications as LiF:Mg,Cu,P, with each type having the disadvantage of a response dependent on energy, particularly at low energies. These results indicate a considerable potential for use in routine control and In vivo ES measurements in mammography. (Author)

  7. Seawater mesocosm experiments in the Arctic uncover differential transfer of marine bacteria to aerosols.

    Science.gov (United States)

    Fahlgren, Camilla; Gómez-Consarnau, Laura; Zábori, Julia; Lindh, Markus V; Krejci, Radovan; Mårtensson, E Monica; Nilsson, Douglas; Pinhassi, Jarone

    2015-06-01

    Biogenic aerosols critically control atmospheric processes. However, although bacteria constitute major portions of living matter in seawater, bacterial aerosolization from oceanic surface layers remains poorly understood. We analysed bacterial diversity in seawater and experimentally generated aerosols from three Kongsfjorden sites, Svalbard. Construction of 16S rRNA gene clone libraries from paired seawater and aerosol samples resulted in 1294 sequences clustering into 149 bacterial and 34 phytoplankton operational taxonomic units (OTUs). Bacterial communities in aerosols differed greatly from corresponding seawater communities in three out of four experiments. Dominant populations of both seawater and aerosols were Flavobacteriia, Alphaproteobacteria and Gammaproteobacteria. Across the entire dataset, most OTUs from seawater could also be found in aerosols; in each experiment, however, several OTUs were either selectively enriched in aerosols or little aerosolized. Notably, a SAR11 clade OTU was consistently abundant in the seawater, but was recorded in significantly lower proportions in aerosols. A strikingly high proportion of colony-forming bacteria were pigmented in aerosols compared with seawater, suggesting that selection during aerosolization contributes to explaining elevated proportions of pigmented bacteria frequently observed in atmospheric samples. Our findings imply that atmospheric processes could be considerably influenced by spatiotemporal variations in the aerosolization efficiency of different marine bacteria. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Accurate fluid force measurement based on control surface integration

    Science.gov (United States)

    Lentink, David

    2018-01-01

    Nonintrusive 3D fluid force measurements are still challenging to conduct accurately for freely moving animals, vehicles, and deforming objects. Two techniques, 3D particle image velocimetry (PIV) and a new technique, the aerodynamic force platform (AFP), address this. Both rely on the control volume integral for momentum; whereas PIV requires numerical integration of flow fields, the AFP performs the integration mechanically based on rigid walls that form the control surface. The accuracy of both PIV and AFP measurements based on the control surface integration is thought to hinge on determining the unsteady body force associated with the acceleration of the volume of displaced fluid. Here, I introduce a set of non-dimensional error ratios to show which fluid and body parameters make the error negligible. The unsteady body force is insignificant in all conditions where the average density of the body is much greater than the density of the fluid, e.g., in gas. Whenever a strongly deforming body experiences significant buoyancy and acceleration, the error is significant. Remarkably, this error can be entirely corrected for with an exact factor provided that the body has a sufficiently homogenous density or acceleration distribution, which is common in liquids. The correction factor for omitting the unsteady body force, {{{ {ρ f}} {1 - {ρ f} ( {{ρ b}+{ρ f}} )}.{( {{{{ρ }}b}+{ρ f}} )}}} , depends only on the fluid, {ρ f}, and body, {{ρ }}b, density. Whereas these straightforward solutions work even at the liquid-gas interface in a significant number of cases, they do not work for generalized bodies undergoing buoyancy in combination with appreciable body density inhomogeneity, volume change (PIV), or volume rate-of-change (PIV and AFP). In these less common cases, the 3D body shape needs to be measured and resolved in time and space to estimate the unsteady body force. The analysis shows that accounting for the unsteady body force is straightforward to non

  9. A bio-thermic seawater desalination system using halophytes

    NARCIS (Netherlands)

    Finck, C.

    2014-01-01

    A bio-thermic seawater desalination system using halophytes was developed and successfully tested. A greenhouse as part of a test rig, with different sorts of mangroves, was installed. Measurements showed promising results concerning fresh water relative yielding rates up to 1.4 kg/h/m2 (leaf

  10. Response Surface Methods For Spatially-Resolved Optical Measurement Techniques

    Science.gov (United States)

    Danehy, P. M.; Dorrington, A. A.; Cutler, A. D.; DeLoach, R.

    2003-01-01

    Response surface methods (or methodology), RSM, have been applied to improve data quality for two vastly different spatially-resolved optical measurement techniques. In the first application, modern design of experiments (MDOE) methods, including RSM, are employed to map the temperature field in a direct-connect supersonic combustion test facility at NASA Langley Research Center. The laser-based measurement technique known as coherent anti-Stokes Raman spectroscopy (CARS) is used to measure temperature at various locations in the combustor. RSM is then used to develop temperature maps of the flow. Even though the temperature fluctuations at a single point in the flowfield have a standard deviation on the order of 300 K, RSM provides analytic fits to the data having 95% confidence interval half width uncertainties in the fit as low as +/- 30 K. Methods of optimizing future CARS experiments are explored. The second application of RSM is to quantify the shape of a 5-meter diameter, ultra-lightweight, inflatable space antenna at NASA Langley Research Center. Photogrammetry is used to simultaneously measure the shape of the antenna at approximately 500 discrete spatial locations. RSM allows an analytic model to be developed that describes the shape of the majority of the antenna with an uncertainty of 0.4 mm, with 95% confidence. This model would allow a quantitative comparison between the actual shape of the antenna and the original design shape. Accurately determining this shape also allows confident interpolation between the measured points. Such a model could, for example, be used for ray tracing of radio-frequency waves up to 95 GHz. to predict the performance of the antenna.

  11. Colour measurements of surfaces to evaluate the restoration materials

    Science.gov (United States)

    Lo Monaco, Angela; Marabelli, Maurizio; Pelosi, Claudia; Picchio, Rodolfo

    2011-06-01

    In this paper two case studies on the application of colour measurements for the evaluation of some restoration materials are discussed. The materials related to the research are: watercolours employed in restoration of wall paintings and preservative/consolidants for wood artifacts. Commercial watercolours, supplied by Maimeri, Windsor&Newton and Talens factories have been tested. Colour measurements have been performed by means of a reflectance spectrophotometer (RS) before and after accelerated ageing of watercolours at 92% relative humidity (RH) and in a Solar Box chamber. The experimental results show that watercolours based on natural earths and artificial ultramarine undergo the main colour changes, expressed as L*, a* and b* variations and total colour difference (▵E*). In the other cases colour differences depend on both watercolour typology and suppliers. The other example concerns the evaluation of colour change due to surface treatment of Poplar (Populus sp.) and chestnut (Castanea sativa L.) wood samples. The wooden samples have been treated with a novel organic preservative/consolidant product that has been tested also in a real case as comparison. The treated samples have been artificially aged in Solar Box chamber equipped with a 280 nm UV filter. Colour has been measured before and after the artificial ageing by means of a RS. Colour changes have been determined also for the main door of an historical mansion in Viterbo, made of chestnut wood, and exposed outdoors.

  12. Advanced metrology of surface defects measurement for aluminum die casting

    Directory of Open Access Journals (Sweden)

    D. Myszka

    2011-07-01

    Full Text Available The scientific objective of the research is to develop a strategy to build computer based vision systems for inspection of surface defects inproducts, especially discontinuities which appear in castings after machining. In addition to the proposed vision inspection method theauthors demonstrates the development of the advanced computer techniques based on the methods of scanning to measure topography ofsurface defect in offline process control. This method allow to identify a mechanism responsible for the formation of casting defects. Also,the method allow investigating if the, developed vision inspection system for identification of surface defects have been correctlyimplemented for an online inspection. Finally, in order to make casting samples with gas and shrinkage porosity defects type, the LGT gas meter was used . For this task a special camera for a semi-quantitative assessment of the gas content in aluminum alloy melts, using a Straube-Pfeiffer method was used. The results demonstrate that applied solution is excellent tool in preparing for various aluminum alloysthe reference porosity samples, identified next by the computer inspection system.

  13. Surface Acoustic Wave Vibration Sensors for Measuring Aircraft Flutter

    Science.gov (United States)

    Wilson, William C.; Moore, Jason P.; Juarez, Peter D.

    2016-01-01

    Under NASA's Advanced Air Vehicles Program the Advanced Air Transport Technology (AATT) Project is investigating flutter effects on aeroelastic wings. To support that work a new method for measuring vibrations due to flutter has been developed. The method employs low power Surface Acoustic Wave (SAW) sensors. To demonstrate the ability of the SAW sensor to detect flutter vibrations the sensors were attached to a Carbon fiber-reinforced polymer (CFRP) composite panel which was vibrated at six frequencies from 1Hz to 50Hz. The SAW data was compared to accelerometer data and was found to resemble sine waves and match each other closely. The SAW module design and results from the tests are presented here.

  14. Channel Storage change: a new remote sensed surface water measurement

    Science.gov (United States)

    Coss, S. P.; Durand, M. T.; Yi, Y.; Guo, Q.; Shum, C. K.; Allen, G. H.; Pavelsky, T.

    2017-12-01

    Here we present river channel storage change (CSC) measurements for 17 major world rivers from 2002-2016. We combined interpolated daily 1 km resolution Global River Radar Altimeter Time Series (GRRATS) river surface elevation data with static widths from the global river Global River Widths from Landsat (GRWL) dataset, to generate preliminary channel storage measurements. CSC is a previously unmeasured component of the terrestrial water balance It is a fundamental Earth science quantity with global bearing on floodplains, ecology, and geochemistry. CSC calculations require only remote sensed data, making them an ideal tool for studying remote regions where hydrological data is not easily accessible. CSC is uniquely suited to determine the role of hydrologic and hydraulic controls in basins with strong seasonal cycles (freeze-up and break-up). The cumulative CSC anomaly can impart spatial details that discharge measurements cannot. With this new measurement, we may be able to determine critical hydrological and hydraulic controls on rapidly changing systems like Arctic rivers. Results for Mississippi River indicate that peak CSC anomaly was the highest in 2011 (12.6 km3) and minimum CSC anomaly was in 2012 (-12.2 km3). Peak CSC has most frequently occurs in May (5 years), but has come as late in the year as July, and as early as January. Results for the Yukon River indicate that peak CSC anomaly was the highest in 2013 (13.9 km3) and minimum CSC anomaly was in 2010 (-14.2 km3). Peak CSC has most frequently come in early to mid-June (4-18), but has occurred in May (19-31) four years in the study period (three of the last 6 years) and once on April 30th.

  15. Measuring sea surface height with a GNSS-Wave Glider

    Science.gov (United States)

    Morales Maqueda, Miguel Angel; Penna, Nigel T.; Foden, Peter R.; Martin, Ian; Cipollini, Paolo; Williams, Simon D.; Pugh, Jeff P.

    2017-04-01

    A GNSS-Wave Glider is a novel technique to measure sea surface height autonomously using the Global Navigation Satellite System (GNSS). It consists of an unmanned surface vehicle manufactured by Liquid Robotics, a Wave Glider, and a geodetic-grade GNSS antenna-receiver system, with the antenna installed on a mast on the vehicle's deck. The Wave Glider uses the differential wave motion through the water column for propulsion, thus guaranteeing an, in principle, indefinite autonomy. Solar energy is collected to power all on-board instrumentation, including the GNSS system. The GNSS-Wave Glider was first tested in Loch Ness in 2013, demonstrating that the technology is capable of mapping geoid heights within the loch with an accuracy of a few centimetres. The trial in Loch Ness did not conclusively confirm the reliability of the technique because, during the tests, the state of the water surface was much more benign than would normally be expect in the open ocean. We now report on a first deployment of a GNSS-Wave Glider in the North Sea. The deployment took place in August 2016 and lasted thirteen days, during which the vehicle covered a distance of about 350 nautical miles in the north western North Sea off Great Britain. During the experiment, the GNSS-Wave Glider experienced sea states between 1 (0-0.1 m wave heights) and 5 (2.5-4 m wave heights). The GNSS-Wave Glider data, recorded at 5 Hz frequency, were analysed using a post-processed kinematic GPS-GLONASS precise point positioning (PPP) approach, which were quality controlled using double difference GPS kinematic processing with respect to onshore reference stations. Filtered with a 900 s moving-average window, the PPP heights reveal geoid patterns in the survey area that are very similar to the EGM2008 geoid model, thus demonstrating the potential use of a GNSS-Wave Glider for marine geoid determination. The residual of subtracting the modelled or measured marine geoid from the PPP signal combines information

  16. Measuring surface temperature of isolated neutron stars and related problems

    Science.gov (United States)

    Teter, Marcus Alton

    New and exciting results for measuring neutron star surface temperatures began with the successful launch of the Chandra X-ray observatory. Among these results are new detections of neutron star surface temperatures which have made it possible to seriously test neutron star thermal evolution theories. The important new temperature determination of the Vela pulsar (Pavlov, et al., 2001a) requires a non-standard cooling scenario to explain it. Apart from this result, we have measured PSR B1055-52's surface temperature in this thesis, determining that it can be explained by standard cooling with heating. Our spectral fit of the combined data from ROSAT and Chandra have shown that a three component model, two thermal blackbodies and an non-thermal power-law, is required to explain the data. Furthermore, our phase resolved spectroscopy has begun to shed light on the geometry of the hot spot on PSR B1055-52's surface as well as the structure of the magnetospheric radiation. Also, there is strong evidence for a thermal distribution over its surface. Most importantly, the fact that PSR B1055-52 does not have a hydrogen atmosphere has been firmly established. To reconcile these two key observations, on the Vela pulsar and PSR B1055-52, we tested neutron star cooling with neutrino processes including the Cooper pair neutrino emission process. Overall, it has been found that a phase change associated with pions being present in the cores of more massive neutron stars explains all current of the data. A transition from neutron matter to pion condensates in the central stellar core explains the difference between standard and non-standard cooling scenarios, because the superfluid suppression of pion cooling will reduce the emissivity of the pion direct URCA process substantially. A neutron star with a mass of [Special characters omitted.] with a medium stiffness equation of state and a T72 type neutron superfluid models the standard cooling case well. A neutron star of [Special

  17. The Natural Geochemistry of Tetrafluoromethane and Sulfur Hexafluoride : Studies of Ancient Mojave Desert Groundwaters, North Pacific Seawaters and the Summit Emissions of Kilauea Volcano

    OpenAIRE

    Deeds, Daniel A

    2008-01-01

    Tetrafluoromethane (CF4) and sulfur hexafluoride (SF6) are potent, long-lived greenhouse gases whose natural atmospheric sources and sinks are poorly understood. CF4 and SF6 concentrations were measured in groundwater, deep and surface seawater, and volcanic gas samples to provide a better constraint on their lithospheric sources to the atmosphere. Groundwaters collected from the Mojave Desert and nearby Big Bear Lake Watershed contain CF4 and SF6 concentrations well in excess of ai...

  18. Freshwater to seawater transitions in migratory fishes

    Science.gov (United States)

    Zydlewski, Joseph D.; Michael P. Wilkie,

    2012-01-01

    The transition from freshwater to seawater is integral to the life history of many fishes. Diverse migratory fishes express anadromous, catadromous, and amphidromous life histories, while others make incomplete transits between freshwater and seawater. The physiological mechanisms of osmoregulation are widely conserved among phylogenetically diverse species. Diadromous fishes moving between freshwater and seawater develop osmoregulatory mechanisms for different environmental salinities. Freshwater to seawater transition involves hormonally mediated changes in gill ionocytes and the transport proteins associated with hypoosmoregulation, increased seawater ingestion and water absorption in the intestine, and reduced urinary water losses. Fishes attain salinity tolerance through early development, gradual acclimation, or environmentally or developmentally cued adaptations. This chapter describes adaptations in diverse taxa and the effects of salinity on growth. Identifying common strategies in diadromous fishes moving between freshwater and seawater will reveal the ecological and physiological basis for maintaining homeostasis in different salinities, and inform efforts to conserve and manage migratory euryhaline fishes.

  19. Precipitation softening: a pretreatment process for seawater desalination.

    Science.gov (United States)

    Ayoub, George M; Zayyat, Ramez M; Al-Hindi, Mahmoud

    2014-02-01

    Reduction of membrane fouling in reverse osmosis systems and elimination of scaling of heat transfer surfaces in thermal plants are a major challenge in the desalination of seawater. Precipitation softening has the potential of eliminating the major fouling and scaling species in seawater desalination plants, thus allowing thermal plants to operate at higher top brine temperatures and membrane plants to operate at a reduced risk of fouling, leading to lower desalinated water costs. This work evaluated the use of precipitation softening as a pretreatment step for seawater desalination. The effectiveness of the process in removing several scale-inducing materials such as calcium, magnesium, silica, and boron was investigated under variable conditions of temperature and pH. The treatment process was also applied to seawater spiked with other known fouling species such as iron and bacteria to determine the efficiency of removal. The results of this work show that precipitation softening at a pH of 11 leads to complete elimination of calcium, silica, and bacteria; to very high removal efficiencies of magnesium and iron (99.6 and 99.2 %, respectively); and to a reasonably good removal efficiency of boron (61 %).

  20. Macroporous monoliths for trace metal extraction from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Yanfeng; Mayes, Richard; Gill, Gary A.; Kuo, Li-Jung; Wood, Jordana R.; Binder, Andrew; Brown, Suree; Dai, Sheng

    2015-05-29

    The viability of seawater-based uranium recovery depends on the uranium adsorption rate and capacity, since the concentration of uranium in the oceans is relatively low (3.3 μgL⁻¹). An important consideration for a fast adsorption is to maximize the adsorption properties of adsorbents such as surface areas and pore structures, which can greatly improve the kinetics of uranium extraction and the adsorption capacity simultaneously. Following this consideration, macroporous monolith adsorbents were prepared from the copolymerization of acrylonitrile (AN) and N,N’-methylenebis(acrylamide) (MBAAm) based on a cryogel method using both hydrophobic and hydrophilic monomers. The monolithic sorbents were tested with simulated seawater containing a high uranyl concentration (–6 ppm) and the uranium adsorption results showed that the adsorption capacities are strongly influenced by the ratio of monomer to the crosslinker, i.e., the density of the amidoxime groups. The preliminary seawater testing indicates the high salinity content of seawater does not hinder the adsorption of uranium.

  1. Rapid determination of 90Sr in seawater

    International Nuclear Information System (INIS)

    Pavlotskaya, F.I.; Moskin, A.I.

    1994-01-01

    A method for determining 90 Sr in seawater that is based on direct isolation and radiochemical purification of daughter 90 Y is proposed. The analysis time is 6-8 h. The chemical yield of the Y-carrier during the 90 Sr determination from 35 liters of seawater varies in the range 37-69%. The analysis uncertainty is 90 Sr from seawater and subsequent isolation of 90 Y

  2. Microbial degradation of pharmaceuticals in estuarine and coastal seawater

    Energy Technology Data Exchange (ETDEWEB)

    Benotti, Mark J. [Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 11794-5000 (United States); Brownawell, Bruce J. [Marine Sciences Research Center, Stony Brook University, Stony Brook, NY 11794-5000 (United States)], E-mail: bruce.brownawell@sunysb.edu

    2009-03-15

    Microbial degradation rates were measured for 19 pharmaceuticals in estuarine and coastal surface water samples. Antipyrine, carbamazepine, cotinine, sulfamethoxazole, and trimethoprim were the most refractory (half-lives, t{sub 1/2} = 35 to >100 days), making them excellent candidates for wastewater tracers. Nicotine, acetaminophen, and fluoxetine were labile across all treatments (t{sub 1/2} = 0.68-11 days). Caffeine, diltiazem, and nifedipine were also and relatively labile in all but one of the treatments (t{sub 1/2} = 3.5-13 days). Microbial degradation of caffeine was further confirmed by production {sup 14}CO{sub 2}. The fastest decay of non-refractory compounds was always observed in more sewage-affected Jamaica Bay waters. Degradation rates for the majority of these pharmaceuticals are much slower than reported rates for small biomolecules, such as glucose and amino acids. Batch sorption experiments indicate that removal of these soluble pharmaceuticals from the water column to sediments is a relatively insignificant removal process in these receiving waters. - Microbial degradation rates were measured for 19 structurally variable pharmaceuticals in wastewater-impacted estuarine and coastal seawater.

  3. Factors That Modulate Properties of Primary Marine Aerosol Generated From Ambient Seawater on Ships at Sea

    Science.gov (United States)

    Keene, William C.; Long, Michael S.; Reid, Jeffrey S.; Frossard, Amanda A.; Kieber, David J.; Maben, John R.; Russell, Lynn M.; Kinsey, Joanna D.; Quinn, Patricia K.; Bates, Timothy S.

    2017-11-01

    Model primary marine aerosol (mPMA) was produced by bubbling clean air through flowing natural seawater in a high-capacity generator deployed on ships in the eastern North Pacific and western North Atlantic Oceans. Physicochemical properties of seawater and mPMA were quantified to characterize factors that modulated production. Differences in surfactant organic matter (OM) and associated properties including surface tension sustained plumes with smaller bubble sizes, slower rise velocities, larger void fractions, and older surface ages in biologically productive relative to oligotrophic seawater. Production efficiencies for mPMA number (PEnum) and mass (PEmass) per unit air detrained from biologically productive seawater during daytime were greater and mass median diameters smaller than those in the same seawater at night and in oligotrophic seawater during day and night. PEmass decreased with increasing air detrainment rate suggesting that surface bubble rafts suppressed emission of jet droplets and associated mPMA mass. Relative to bubbles emitted at 60 cm depth, PEnum for bubbles emitted from 100 cm depth was approximately 2 times greater. mPMA OM enrichment factors (EFs) and mass fractions based on a coarse frit, fine frits, and a seawater jet exhibited similar size-dependent variability over a wide range in chlorophyll a concentrations. Results indicate that the physical production of PMA number and mass from the ocean surface varies systematically as interrelated functions of seawater type and, in biologically productive waters, time of day; bubble injection rate, depth, size, and surface age; and physical characteristics of the air-water interface whereas size-resolved OM EFs and mass fractions are relatively invariant.

  4. Performance of OTEC Heat Exchanger Materials in Tropical Seawaters

    Science.gov (United States)

    Larsen-Basse, Jorn

    1985-03-01

    The corrosion of several aluminum alloys in flowing Hawaiian surface seawater and water from 600 m depth for exposure periods up to three years has been studied. The alloys tested in cold water were Alclad (7072) 3003 and 3004; and bare 3004 and 5052). All show some pitting. Pit growth is slow, and pits do not penetrate the cladding. In the warm water, only uniform corrosion has been found. All alloys corrode at the same, low rate of˜3 μm/year after an initial short period of more rapid corrosion. This behavior is closely linked to the formation of a protective inorganic scale film on the surface. It consists of precipitated scale minerals from the seawater and aluminum corrosion products. The results indicate that OTEC evaporator heat exchangers constructed of aluminum alloys should have acceptable service lives.

  5. Sorption isolation of strontium from seawater

    International Nuclear Information System (INIS)

    Avramenko, V.A.; Zheleznov, V.V.; Kaplun, E.V.; Sokol'nitskaya, T.A.; Yukhkam, A.A.

    2001-01-01

    Sorption isolation of strontium from seawater is considered and prospects of use of selective adsorbents for purification of seawater or liquid radioactive wastes mixed with seawater from 90 Sr are discussed. Comparative analysis of sorptive properties of adsorbents of different nature is done. It is shown that sorption-reagent materials developed by authors can to afford effective separation of 90 Sr from seawater. Possible mechanism of strontium sorption by these adsorbents is considered. The prospect of their use for purification of liquid radioactive wastes from strontium is shown [ru

  6. Measuring surface current velocities in the Agulhas region with ASAR

    CSIR Research Space (South Africa)

    Rouault, MJ

    2010-01-01

    Full Text Available Surface current information collected over the Agulhas Current region and derived from the Doppler centroid anomalies of the Advanced Synthetic Aperture Radar (ASAR) are examined. The sources of errors and potential use of the radar surface...

  7. A new approach for determination of fouling potential by colloidal nanoparticles during reverse osmosis (RO) membrane filtration of seawater

    Science.gov (United States)

    Park, Ji Yeon; Lim, Sungil; Park, Kihong

    2013-04-01

    A direct measurement of number concentration of colloidal nanoparticles (15-450 nm) in water was made with the membrane filtration-differential mobility analyzer technique, and its corresponding flux decline rate (FDR) was determined by laboratory-scale RO fouling test unit using varying number concentrations of silica nanoparticles in artificial seawaters. This relationship was used to predict fouling potential of colloidal nanoparticles in reverse osmosis (RO) membrane process of seawaters in RO plant. It was found that the FDR linearly increased with the increasing number of colloidal nanoparticles for the given concentration range and that the relationship between the number concentration and the FDR also depended on RO membrane surface properties. Data for estimated FDR values for natural seawaters after pretreatment showed a clear difference among samples, which is contrary to the pre-existing index such as silt density index and modified fouling index. Our data suggest that measurement of colloidal nanoparticles is useful for selection of proper pretreatment and successful operation of RO membrane process along with other particle fouling predictors accounting for large particles (>450 nm).

  8. A new approach for determination of fouling potential by colloidal nanoparticles during reverse osmosis (RO) membrane filtration of seawater

    International Nuclear Information System (INIS)

    Park, Ji Yeon; Lim, Sungil; Park, Kihong

    2013-01-01

    A direct measurement of number concentration of colloidal nanoparticles (15–450 nm) in water was made with the membrane filtration-differential mobility analyzer technique, and its corresponding flux decline rate (FDR) was determined by laboratory-scale RO fouling test unit using varying number concentrations of silica nanoparticles in artificial seawaters. This relationship was used to predict fouling potential of colloidal nanoparticles in reverse osmosis (RO) membrane process of seawaters in RO plant. It was found that the FDR linearly increased with the increasing number of colloidal nanoparticles for the given concentration range and that the relationship between the number concentration and the FDR also depended on RO membrane surface properties. Data for estimated FDR values for natural seawaters after pretreatment showed a clear difference among samples, which is contrary to the pre-existing index such as silt density index and modified fouling index. Our data suggest that measurement of colloidal nanoparticles is useful for selection of proper pretreatment and successful operation of RO membrane process along with other particle fouling predictors accounting for large particles (>450 nm).

  9. ROUGHNESS ON WOOD SURFACES AND ROUGHNESS MEASUREMENT METHODS

    OpenAIRE

    İsmail Aydın; Gürsel Çolakoğlu

    2003-01-01

    Some visual characteristics of wood such as color, pattern and texture determine the quality of manufactured products. Surface properties of wood material are important both in production and marketing after production. Initial studies related to the roughness of wood surface were begun in early 1950’s. However, no general agreed standardization can not have been developed for wood surfaces. Surface roughness of wood is function of the production process, product type and the natural anatomic...

  10. Physiological indices of seawater readiness in postspawning steelhead kelts

    Science.gov (United States)

    Buelow, Jessica; Moffitt, Christine M.

    2015-01-01

    Management goals to improve the recovery of steelhead (Oncorhynchus mykiss) stocks at risk of extinction include increasing the proportion of postspawning fish that survive and spawn again. To be successful, postspawning steelhead (kelts) migrating downstream to the ocean must prepare physiologically and physically for a seawater transition. We sampled blood, gill filaments, and evaluated the external condition of migrating kelts from an ESA-listed population in the Snake/Columbia River system over two consecutive years to evaluate their physiological readiness for transition to seawater. We chose attributes often considered as measures of preparation for seawater in juveniles, including gill Na+,K+ ATPase activity, plasma electrolytes and hormones to consider factors related to external condition, size and sex. We found kelts in good external condition had plasma profiles similar to downstream-migrating smolts. In addition, we found more than 80% of kelts ranked in good external condition had smolt-like body silvering. We compared measures from migrating kelts with samples obtained from hatchery fish at the time of spawning to confirm that Na+, K+ ATPase activity in kelts was significantly elevated over spawning fish. We found significant differences in gill Na+, K+ ATPase activity in migrating kelts between the years of sampling, but little indication of influence of fish condition. We conclude that the postspawning steelhead sampled exhibited a suite of behaviours, condition and physiology characteristic of fish prepared for successful transition to a seawater environment.

  11. Laboratory experiments to investigate radionuclide enrichment in the sea-surface microlayer

    International Nuclear Information System (INIS)

    Hickmott, S.J.B.

    1982-02-01

    Samples of simulated seawater, and seawater from the Irish Sea, were contained in a plastic tank in the laboratory, and bubbles were passed through them to burst at the water surface. The emitted jet droplets, as representing the surface microlayer, were collected on filter papers. Such measurements are easier to perform than similar measurements at sea, and the lack of waves enables greater collection efficiencies to be obtained. The droplet samples were analysed for stable Na, 137 Cs and actinides, and compared with the concentrations in the bulk tank water, in order to examine possible concentration factors for radionuclides in the surface microlayer. (author)

  12. Measuring evaporation from soil surfaces for environmental and ...

    African Journals Online (AJOL)

    There are many reasons for the need to assess rates and quantities of evaporation or evapotranspiration from natural soil surfaces, the surfaces of deposits of mine or industrial waste, or soil-covered waste surfaces. These include assessing water balances for nearsurface soil strata, landfills, tailings dams and waste dumps ...

  13. Effects of drop size and measuring condition on static contact angle measurement on a superhydrophobic surface with goniometric technique

    International Nuclear Information System (INIS)

    Seo, Kwangseok; Kim, Minyoung; Kim, Do Hyun; Ahn, Jeong Keun

    2015-01-01

    It is not a simple task to measure a contact angle of a water drop on a superhydrophobic surface with sessile drop method, because a roll-off angle is very low. Usually contact angle of a water drop on a superhydrophobic surface is measured by fixing a drop with intentional defects on the surface or a needle. We examined the effects of drop size and measuring condition such as the use of a needle or defects on the static contact angle measurement on superhydrophobic surface. Results showed that the contact angles on a superhydrophobic surface remain almost constant within intrinsic measurement errors unless there is a wetting transition during the measurement. We expect that this study will provide a deeper understanding on the nature of the contact angle and convenient measurement of the contact angle on the superhydrophobic surface.

  14. Organic Carbon Reduction in Seawater Reverse Osmosis (SWRO) Plants, Jeddah, Saudi Arabia

    KAUST Repository

    Alshahri, Abdullah

    2015-12-01

    Desalination is considered to be a major source of usable water in the Middle East, especially the Gulf countries which lack fresh water resources. A key and sometimes the only solution to produce high quality water in these countries is through the use of seawater reverse osmosis (SWRO) desalination technology. Membrane fouling is an economic and operational defect that impacts the performance of SWRO desalination technology. To limit this fouling phenomenon, it is important to implement the appropriate type of intake and pre-treatment system design. In this study, two types of systems were investigated, a vertical well system and a surface-water intake at a 9m depth. The purpose of this investigation is to study the impact of the different intake systems and pre-treatment stages in minimizing the concentrations of algae, bacteria, natural organic matter (NOM) and transparent exopolymer particles (TEP), in the feed water prior to pre-treatment, through the pre-treatment stages, and in the product water and concentrate. Water samples were collected from the surface seawater, the intakes (wells for site A, 9 m depth open ocean intake at site B), after the media filter, after the cartridge filter, and from the permeate and reject streams. The measured parameters included physical parameters, algae, bacteria, total organic carbon (TOC), fractions of dissolved NOM, particulate and colloidal TEP. The results of this study prove that the natural filtration and biological treatment of the seawater which occur in the aquifer matrix are very effective in improving the raw water quality to a significant degree. The results demonstrated that algae and biopolymers were 100% removed, the bacterial concentrations were significantly removed and roughly 50% or greater of TOC concentrations was eliminated by the aquifer matrix at site A. The aquifer feeding the vertical wells reduced TEP concentrations, but to differing degree. There is a slight decrease in the concentrations of

  15. Entrance surface dose measurements in pediatric radiological examinations

    International Nuclear Information System (INIS)

    Ribeiro, L.A.; Yoshimura, E.M.

    2008-01-01

    A survey of pediatric radiological examinations was carried out in a reference pediatric hospital of the city of Sao Paulo, in order to investigate the doses to children undergoing conventional X-ray examinations. The results showed that the majority of pediatric patients are below 4 years, and that about 80% of the examinations correspond to chest projections. Doses to typical radiological examinations were measured in vivo with thermoluminescent dosimeters (LiF: Mg, Ti and LiF: Mg, Cu, P) attached to the skin of the children to determine entrance surface dose (ESD). Also homogeneous phantoms were used to obtain ESD to younger children, because the technique uses a so small kVp that the dosimeters would produce an artifact image in the patient radiograph. Four kinds of pediatric examinations were investigated: three conventional examinations (chest, skull and abdomen) and a fluoroscopic procedure (barium swallow). Relevant information about kVp and mAs values used in the examinations was collected, and we discuss how these parameters can affect the ESD. The ESD values measured in this work are compared to reference levels published by the European Commission for pediatric patients. The results obtained (third-quartile of the ESD distribution) for chest AP examinations in three age groups were: 0.056 mGy (2-4 years old); 0.068 mGy (5-9 years old); 0.069 mGy (10-15 years old). All of them are below the European reference level (0.100 mGy). ESD values measured to the older age group in skull and abdomen AP radiographs (mean values 3.44 and 1.20 mGy, respectively) are above the European reference levels (1.5 mGy to skull and 1.0 mGy to abdomen). ESD values measured in the barium swallow examination reached 10 mGy in skin regions corresponding to thyroid and esophagus. It was noticed during this survey that some technicians use, improperly, X-ray fluoroscopy in conventional examinations to help them in positioning the patient. The results presented here are a

  16. Effect of seawater salinity on pore-size distribution on a poly(styrene)-based HP20 resin and its adsorption of diarrhetic shellfish toxins.

    Science.gov (United States)

    Fan, Lin; Sun, Geng; Qiu, Jiangbing; Ma, Qimin; Hess, Philipp; Li, Aifeng

    2014-12-19

    In the present study, okadaic acid (OA) and dinophysistoxin-1 (DTX1) were spiked into artificial seawater at low, medium and high estuarine salinities (9‰, 13.5‰ and 27‰). Passive samplers (HP20 resin) used for solid phase adsorption toxin tracking (SPATT) technology were exposed in these seawaters for 12-h periods. Adsorption curves well fitted a pseudo-secondary kinetics model. The highest initial sorption rates of both toxins occurred in the seawater of medium salinity, followed by seawater of low and high estuarine salinity. Pore volumes of micropores (seawater at high and low salinity but not in seawater at medium salinity, which demonstrated that the toxin molecules entered into micropores and mesopores (below 10nm in size) in seawaters of high and low salinity. More toxin or other matrix agglomerates were displayed on the surface of resin deployed in the seawater of medium salinity. Taking into consideration the pore-size distribution and surface images, it appears that intra-particle diffusion governs toxin adsorption in seawater at high salinity while film diffusion mainly controls the adsorption process in seawater at medium salinity. This is the first study to confirm that molecules of OA and DTX1 are able to enter into micropores (seawater with high salinity (∼27‰). Copyright © 2014 Elsevier B.V. All rights reserved.

  17. UAV BASED BRDF-MEASUREMENTS OF AGRICULTURAL SURFACES WITH PFIFFIKUS

    Directory of Open Access Journals (Sweden)

    G. J. Grenzdörffer

    2012-09-01

    Full Text Available BRDF is a common problem in remote sensing and also in oblique photogrammetry. Common approaches of BRDF-measurement with a field goniometer are costly and rather cumbersome. UAVs may offer an interesting alternative by using a special flight pattern of oblique and converging images. The main part of this paper is the description of a photogrammetric workflow in order to determine the anisotropic reflection properties of a given surface. Due to the relatively low flying heights standard procedures from close range photogrammetry were adopted for outdoor usage. The photogrammetric processing delivered automatic and highly accurate orientation information with the aid of coded targets. The interior orientation of the consumer grade camera is more or less stable. The radiometrically corrected oblique images are converted into ortho photos. The azimuth and elevation angle of every point may then be computed. The calculated anisotropy of a winter wheat plot is shown. A system four diagonally-looking cameras (Four Vision and an additional nadir looking camera is under development. The multi camera system especially designed for a Micro- UAV with a payload of min 1 kg. The system is composed of five industrial digital frame cameras (1.3 Mpix CCD-chips, 15 fp/s with fixed lenses. Also special problems with the construction of a light weight housing of the multi camera solution are covered in the paper.

  18. Recovery of lithium from seawater

    International Nuclear Information System (INIS)

    Ooi, Kenta; Miyai, Yoshitaka; Katoh, Shunsaku; Abe, Mitsuo.

    1989-01-01

    Lithium has been used for air conditioners, aluminum refining, ceramics, organic metal compounds, batteries and many other uses. Besides, attention is paid as the aluminum-lithium alloys as aircraft materials, and the raw materials for large capacity batteries and nuclear fusion reactors for the future. The amount of lithium resources has been estimated as 14 million tons, and is relatively abundant, but when the future increase of demand is considered, it is not necessarily sufficient. Japan lacks lithium resources, and the stable ensuring of the resources has become an important problem. Seawater contains lithium by 170 μg/l, and its total amount reaches 230 billion tons. The process of recovering lithium from seawater, geothermal water and natural gas brine has been actively researched since 10 years ago centering around Japan. At present, the search for the adsorbent that effectively collects lithium is the main subject. Also the recovery by coprecipitation has been investigated basically. The inorganic adsorbent for lithium is classified into aluminum type, compound antimonic acid type, layered compound type, ion sieve oxide type and others. Their lithium adsorption performance and adsorption mechanism are different remarkably, therefore, these of each group are described. (K.I.) 70 refs

  19. Chemical Characteristics of Seawater and Sediment in the Yap Trench

    Science.gov (United States)

    Ding, H.; Sun, C.; Yang, G.

    2017-12-01

    In June 2016, seawater samples at sediment-seawater interface and sediment samples were collected by the he Jiaolong, China's manned submersible, at four sampling sites located in the Yap Trench. Seawater samples from different depths of the trench were also collected by CTD. Chemical parameters, including pH, alkanility, concentrations of dissolved inorganic carbon, dissolved and total organic carbon, methane, dimethylsulfoniopropionate, nutrients, carbohydrates, and amino acids were analyzed in the seawater samples. Concentrations of total organic carbon, six constant elements and nine trace elements were determined in the sediment samples. All the vertical profiles of the chemical parameters in the seawater have unique characteristics. Our resluts also showed that the carbonate compensation depth (CCD) was between 4500 m and 5000 m in the trench. The hadal sediment at 6500 m depth under the CCD line was siliceous ooze favored for the burial of orgaic carbon, attributed to accumulation of surface sediment by gravity flow. The abyssal sediment at the 4500 m depth was calcareous ooze. Various microfossils, such as discoasters and diatoms, were identified in different sediment layers of the sediment samples.Based on the ratios of Fe/Al and Ti/Al, and the correlation between different elements, the sediment in the Yap Trench were derived from biogenic, terrestrial, volcanic and autogenic sources. The ratios of Ni/Co and V/Cr showed that the deposition environment of the trench should be oxidative, arributed to inflow of the Antractic bottom oxygen-rich seawater.The high concentraiont of Ca in the sediment from the station 371-Yap-S02 below 4 cm depth indicated that there was no large-scale volcanic eruption in the research area and the volcanic materials in the sediment might orginated from the Mariana Volcanic Arc, and the Carolyn Ridge has been slowly sinking on the east side of the trench due to plate subduction. This study is the first systematic study of

  20. On the measurement of the surface energy budget over a land ...

    Indian Academy of Sciences (India)

    The measurement of surface energy balance over a land surface in an open area in Bangalore is reported. Measurements of all variables needed to calculate the surface energy balance on time scales longer than a week are made. Components of radiative fluxes are measured while sensible and latent heat fluxes are ...

  1. Plutonium determination in seawater by inductively coupled plasma mass spectrometry: A review.

    Science.gov (United States)

    Cao, Liguo; Bu, Wenting; Zheng, Jian; Pan, Shaoming; Wang, Zhongtang; Uchida, Shigeo

    2016-05-01

    Knowing the concentration and isotopic ratio of Pu in seawater is of critical importance for assessing Pu contamination and investigating oceanic processes. In recent decades, the concentration of (239+240)Pu in seawater, particularly for surface seawater, has presented an exponential decreasing trend with time; thus determination of Pu in seawater has become a challenge nowadays. Here, we have summarized and critically discussed a variety of reported analytical methods for Pu determination in seawater sample based on inductively coupled plasma mass spectrometry (ICP-MS) analytical technique for rapid ultra-trace detection of Pu. Generally, pretreatments for seawater sample include co-precipitation, valence adjustment and chemical separation and purification procedures, all of which are comprehensively reviewed. Overall, the selected anion-exchange, extraction resins and operation condition are important for decontamination of interference from matrix elements and achieving satisfactory chemical yields. In addition, other mass spectrometric and radiometric detections are briefly addressed and compared with the focus on assessing ICP-MS. Finally, we discuss some issues and prospects in determination and application of Pu isotopes in seawater samples for future research. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Seawater immersion aggravates burn-associated lung injury and inflammatory and oxidative-stress responses.

    Science.gov (United States)

    Ma, Jun; Wang, Ying; Wu, Qi; Chen, Xiaowei; Wang, Jiahan; Yang, Lei

    2017-08-01

    With the increasing frequency of marine development activities and local wars at sea, the incidence of scald burns in marine accidents or wars has been increasing yearly. Various studies have indicated that immersion in seawater has a systemic impact on some organs of animals or humans with burn. Thus, for burn/scald injuries after immersion in seawater, it is desirable to study the effects and mechanisms of action on important organs. In the present study, we aimed to investigate the effect of immersion in seawater on lung injury, inflammatory and oxidative-stress responses in scalded rats. The structural damage to lungs was detected by hematoxylin and eosin staining and the results showed that seawater immersion aggravated structural lung injury in scalded rats. The expression of HMGB1 in lung tissues was detected by immunohistochemical analysis and the results showed that seawater immersion increased HMGB1 expression in lung tissues of scalded rats. Apoptosis in lung tissues was detected by terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling (TUNEL) staining and the results showed that seawater immersion increased apoptosis rate in lung tissues of scalded rats. In addition, the expression levels of TNF-α, IL-6, IL-8, SOD, and MDA in serum were analyzed by enzyme-linked immunosorbent assays (ELISAs) and the results showed that seawater immersion induced secretion of proinflammatory factors (TNF-α, IL-6, and IL-8), increased MDA protein level, and suppressed SOD activity in the serum of scalded rats. Furthermore, measurement of plasma volume and pH showed that seawater immersion decreased plasma volume and pH value. Overall, the results indicated that all effects induced by immersion in seawater in scalded rats are more pronounced than those induced by freshwater. In conclusion, seawater immersion may aggravate lung injury and enhance inflammatory and oxidative-stress responses after burn. Copyright © 2017 Elsevier Ltd and ISBI. All rights

  3. Analysis of seawater flow through optical fiber

    Science.gov (United States)

    Fernández López, Sheila; Carrera Ramírez, Jesús; Rodriguez Sinobar, Leonor; Benitez, Javier; Rossi, Riccardo; Laresse de Tetto, Antonia

    2015-04-01

    The relation between sea and coastal aquifer is very important to the human populations living in coastal areas. The interrelation involves the submarine ground water discharge of relatively fresh water to the sea and the intrusion of sea water into the aquifer, which impairs the quality of ground water. The main process in seawater intrusion is managed by fluid-density effects which control the displacement of saline water. The underlain salinity acts as the restoring force, while hydrodynamic dispersion and convection lead to a mixing and vertical displacement of the brine. Because of this, a good definition of this saltwater-freshwater interface is needed what is intimately joined to the study of the movements (velocity fields) of fresh and salt water. As it is well known, the flow of salt water studied in seawater intrusion in stationary state, is nearly null or very low. However, in the rest of cases, this flux can be very important, so it is necessary its study to a better comprehension of this process. One possible manner of carry out this analysis is through the data from optical fiber. So, to research the distribution and velocity of the fresh and saltwater in the aquifer, a fiber optic system (OF) has been installed in Argentona (Baix Maresme, Catalonia). The main objective is to obtain the distributed temperature measurements (OF-DTS) and made progress in the interpretation of the dynamic processes of water. For some applications, the optical fiber acts as a passive temperature sensor but in our case, the technique Heated Active Fiber Optic will be used. This is based on the thermal response of the ground as a heat emission source is introduced. The thermal properties of the soil, dependent variables of soil water content, will make a specific temperature distribution around the cable. From the analyzed data we will deduce the velocity field, the real objective of our problem. To simulate this phenomenon and the coupled transport and flow problem

  4. Continental fragmentation and the strontium isotopic evolution of seawater.

    Science.gov (United States)

    Eric, H.; Jean Pascal, C.

    2008-12-01

    The time evolution of the strontium isotopic composition of seawater over the last 600 million years has the form of an asymmetric trough. The values are highest in the Cambrian and recent and lowest in the Jurassic. Superimposed on this trend are a number of smaller oscillations. The mechanisms responsible for these global isotopic fluctuations are subject to much debates. In order to get a quantitative picture of the changing paleogeography, we have characterized land-ocean distributions over Late Proterozoic to Phanerozoic times from measurement of perimeters and areas of continental fragments, based on paleomagnetic reconstructions. These measurements served to calculate geophysically constrainted breakup and scatter indexes of continental land masses from 0 to 1100 Ma (Cogne and Humler, 2008). Both parameters (strontium isotopic ratios of seawater and continental fragmentation indexes) are obviously highly correlated during the last 600 Ma. Low continental dispersion (that is large continental land masses) are associated with low seawater strontium isotopic ratios (that is when the continental inputs to oceans are minimum) and high continental dispersion (that is relatively small and widely distributed continents) with high seawater strontium isotopic ratios (that is when the continental input to ocean is maximum). Importantly, this first order evolution appears to conflict with the common idea of mountains erosion as a source for radiogenic strontium to oceans because high strontium isotopic ratios in seawater correspond to period of maximum dispersion of continents and not with period of general collisions. At first glance, it would seem that continental erosion increases with the degree of continental dispersion. Models showing that continental precipitation increases when continental masses are smaller and more widely dispersed and/or the length of continental margins available for rivers to carry continental material to oceans are thus favoured in order

  5. Energy Implications of Seawater Desalination (Invited)

    Science.gov (United States)

    Cooley, H.; Heberger, M. G.

    2013-12-01

    Freshwater has traditionally come from rivers, lakes, streams, and groundwater aquifers. As demand increases and climate change alters the location and timing of water supply, these traditional sources are becoming unavailable, more difficult, or increasingly expensive to develop. As a result, many communities are switching to alternative sources of water. Interest in pursuing seawater desalination is high in many coastal communities. In California, for example, 17 plants are proposed for development along the California coast and two in Mexico. Water managers are pursing desalination because is a local supply that can help diversify the water supply portfolio. Additionally, it is a reliable supply, which can be especially valuable during a drought. But removing the salt from seawater is an energy-intensive process that consumes more energy per gallon than most other water supply and treatment options. These energy requirements are key factors that will impact the extent and success of desalination in California. Energy requirements for seawater desalination average about 4.0 kWh per cubic meter (m3) of water produced. By comparison, the least energy-intensive options of local sources of groundwater and surface water require 0 - 0.90 kWh per m3; wastewater reuse, depending on treatment levels, may require from 0.26 - 2.2 kWh per m3. Beyond the electricity required for the desalination facility itself, producing any new source of water, including through desalination, increases the amount of energy required to deliver and use the water produced as well as collect, treat, and dispose of the wastewater generated. Energy is the largest single variable cost for a desalination plant, varying from one-third to more than one-half the cost of produced water. Building a desalination plant may reduce a water utility's exposure to water reliability risks at the added expense of an increase in exposure to energy price risk. In dependent on hydropower, electricity prices tend to

  6. Sustainable and safe energy supply with seawater uranium fueled HTGR and its economy

    International Nuclear Information System (INIS)

    Fukaya, Y.; Goto, M.

    2017-01-01

    Highlights: • We discussed uranium resources with an energy security perspective. • We concluded seawater uranium is preferable for sustainability and energy security. • We evaluated electricity generation cost of seawater uranium fueled HTGR. • We concluded electricity generation with seawater uranium is reasonable. - Abstract: Sustainable and safe energy supply with High Temperature Gas-cooled Reactor (HTGR) fueled by uranium from seawater have been investigated and discussed. From the view point of safety feature of self-regulation with thermal reactor of HTGR, the uranium resources should be inexhaustible. The seawater uranium is expected to be alternative resources to conventional resources because it exists so much in seawater as a solute. It is said that 4.5 billion tons of uranium is dissolved in the seawater, which corresponds to a consumption of approximately 72 thousand years. Moreover, a thousand times of the amount of 4.5 trillion tU of uranium, which corresponds to the consumption of 72 million years, also is included in the rock on the surface of the sea floor, and that is also recoverable as seawater uranium because uranium in seawater is in an equilibrium state with that. In other words, the uranium from seawater is almost inexhaustible natural resource. However, the recovery cost with current technology is still expensive compared with that of conventional uranium. Then, we assessed the effect of increase in uranium purchase cost on the entire electricity generation cost. In this study, the economy of electricity generation of cost of a commercial HTGR was evaluated with conventional uranium and seawater uranium. Compared with ordinary LWR using conventional uranium, HTGR can generate electricity cheaply because of small volume of simple direct gas turbine system compared with water and steam systems of LWR, rationalization by modularizing, and high thermal efficiency, even if fueled by seawater uranium. It is concluded that the HTGR

  7. Modeling and simulating the bidirectional reflectance distribution function (BRDF) of seawater covered by oil slicks

    Science.gov (United States)

    Ren, Zijian; Ma, Chunyong; Chen, Lu; Chen, Ge

    2016-05-01

    A high-efficiency anisotropic model for bidirectional reflectance distribution function (BRDF) of seawater covered by oil slicks (SWCOS) was proposed. This model was set by combining a BRDF model for anisotropic rough sea surface whose slopes follow Gaussian distribution and the two-beam inference theory of a thin film. We have simulated the BRDFs of oil slicks by using the above model and the measured complex refractive index data of Romashkino crude oil. In addition, the relationships between the BRDF of oil slicks and the wind speed of sea surface, thickness of oil slick, complex refractive index of crude oil and the incident zenith angle were analyzed. Also, the differences between optical characteristics of clean water and of polluted water were discussed in the context of the optical contrast of SWCOS. With high simulation speed and reliable simulation precision, this model provides a theoretical basis for rapid detection of oil spill.

  8. An instrument for the measurement of road surface reflection properties

    DEFF Research Database (Denmark)

    Corell, Dennis Dan; Sørensen, K.

    2017-01-01

    surfaces in use have changed - for instance to road surface types with less noise from wheel passages. Because of this, a co-operation between the road administrations of the Nordic countries (abbreviated NMF) decided to construct a portable instrument to be used on selections of traffic roads within...

  9. Measurement of Sky Surface Brightness Fluctuations at λ=4 Microns

    Science.gov (United States)

    Xu, Jing; Bock, James J.; Ganga, Ken M.; Gorjian, Varoujan; Uemizu, Kazunori; Kawada, Mitsunobu; Lange, Andrew E.; Matsumoto, Toshio; Watabe, Toyoki

    2002-12-01

    We present a measurement of faint-source confusion in deep, wide-field 4 μm images. The 1.8d×1.8d images with 17" resolution are centered about the nearby edge-on spiral galaxies NGC 4565 and NGC 5907. After removing statistical noise and gain fluctuations in the focal plane array, we measure spatial fluctuations in the sky brightness to be δνIν=2.74+/-0.14 nW m-2 sr-1, approximately 1% of the diffuse background level observed in a single pixel. The brightness fluctuations are confirmed to be associated with the sky by subtracting sequential images of the same region. An autocorrelation analysis shows the fluctuations are well described by unresolved point sources. We see no evidence for surface brightness fluctuations on larger angular scales (2'S)=1.04+0.86-0.34 nW m-2 sr-1 to the cosmic infrared background, evaluated at S=4.0×10-8 nW m-2. From the fluctuation data we can determine the integrated source counts N(>S)=1.79+0.26-0.40×107 sr-1, evaluated at S=4.0×10-8 nW m-2. The observed fluctuations are consistent with reddened K-band galaxy number counts. The number counts of extracted point sources with flux νFν>6.3×10-7 nW m-2 are dominated by stars and agree well with the Galactic stellar model of Wright & Reese. Removing the stellar contribution from DIRBE maps with zodiacal subtraction results in a residual brightness of 14.0+/-2.6 (22.2+/-5.9) nW m-2 sr-1 at 3.5 (4.9) μm for the NGC 5907 field and 24.0+/-2.7 (36.8+/-6.0) nW m-2 sr-1 at 3.5 (4.9) μm for the NGC 4565 field. The NGC 5907 residuals are consistent with tentative detections of the infrared background reported by Dwek & Arendt, Wright & Reese, and Gorjian, Wright, & Chary.

  10. Colloidal nature of radionuclides in seawater

    International Nuclear Information System (INIS)

    Feldman, I.

    1976-01-01

    There is considerable doubt that equilibrium calculations, i.e., employing solubility products and complex-ion stability constants, are valid for the submicro concentrations of radionuclides in seawater. The existence of radiocolloids should be expected in seawater. The great tendency of radiocolloids to adsorb onto finely divided hydrous oxides makes their formation of significance in seawater, especially for artificial radionuclides. The subject of radiocolloid formation is reviewed in this chapter. It is shown that the 226 Ra/ 230 Th/U relationship found in seawater can be explained from the fact that the tendencies of these elements to form radiocolloids in seawater should decrease in order thorium greater than radium much greater than uranium. This explanation is much simpler than the prevailing oceanographic one. The theories for radiocolloid formation are discussed. The recent theory of Jones and Healy for the adsorption of hydrolyzable metal ions onto hydrous oxides is reviewed briefly, and its relevance to radiocolloid formation is pointed out

  11. Colloidal nature of radionuclides in seawater

    International Nuclear Information System (INIS)

    Feldman, I.

    1976-01-01

    There is considerable doubt that equilibrium calculations, i.e., employing solubility products and complex-ion stability constants, are valid for the submicro concentrations of radionuclides in seawater. The existence of radiocolloids should be expected in seawater. The great tendency of radiocolloids to adsorb onto finely-divided hydrous oxides makes their formation of significance in seawater, especially for artificial radionuclides. The subject of radiocolloid formation is reviewed in this chapter. It is shown that the 226 Ra/ 230 Th/U relationship found in seawater can be explained from the fact that the tendencies of these elements to form radiocolloids in seawater should decrease in order thorium > radium much greater than uranium. This explanation is much simpler than the prevailing oceanographic one. The theories for radiocolloid formation are discussed. The recent theory of Jones and Healy for the adsorption of hydrolyzable metal ions onto hydrous oxides is reviewed briefly, and its relevance to radiocolloid formation is pointed out

  12. The influence of seawater properties on toxicity of copper pyrithione and its degradation product to brine shrimp Artemia salina.

    Science.gov (United States)

    Lavtizar, Vesna; Kimura, Daisuke; Asaoka, Satoshi; Okamura, Hideo

    2018-01-01

    Copper pyrithione (CuPT) is a biocide, used worldwide to prevent biofouling on submerged surfaces. In aquatic environments it rapidly degrades, however, one of the degradation products (HPT) is known to react with cupric ion back to its parent compound. Not much is known about the behavior and toxicity of CuPT and its degradation product HPT in different water systems. Hence, our aim was to investigate the ecotoxicity of CuPT, HPT as well as Cu 2+ to the brine shrimp Artemia salina in natural seawater and organic matter-free artificial seawater. Moreover, in order to elucidate the influence of ionic strength of water on CuPT toxicity, tests were performed in water media with modified salinity. The results showed that CuPT was the most toxic to the exposed crustaceans in a seawater media with the highest salinity and with no organic matter content. HPT in a presence of cupric ion converted to CuPT, but the measured CuPT concentrations and the mortality of A. salina in natural water were lower than in artificial water. The toxicity of CuPT to A. salina was significantly influenced by the organic matter content, salinity, and proportions of constituent salts in water. In a combination with cupric ion, non-hazardous degradation product HPT exhibits increased toxicity due to its rapid transformation to its parent compound. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Impregnation/Agglomeration Laboratory Tests of Heavy Fuel from Prestige to Improve Its Manageability and Removal from Seawater Surface. (Physical Behaviour of Fuel Agglomates); Ensayos a Nivel de Laboratorio de Impregnacion/Aglomeracion del Fuel Procedente del Prestige para Facilitar su Manipulacion y Recogida en la Superficie del Mar (Comportamiento Fisico de los Aglomerados de Fuel)

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Frutos, F. J.; Rodriguez, V.; Otero, J.

    2002-07-01

    The handling and removal problems showed by heavy fuel floating in seawater could be improved or solved by using materials that agglomerate it. These materials must fulfill the following condition: be inert materials in marine environment, the agglomerated fuel/material should float and its application and removal should be done using simple technologies. Based on these requirements, clay minerals, pine chips, mineral coal and charcoal were selected. The preliminary results on impregnation/agglomeration with the materials mentioned above of heavy fuel from Prestige at lab scale are presented in this paper. The results have shown that only hydrophobic materials, such as mineral coal and charcoal, are able to agglomerate with fuel, which is also a hydrophobic substance. Whereas the agglomerates fuel/mineral coal sink, the agglomerates fuel/charcoal keep floating on water surface. It can be concluded that the addition of charcoal on dispersed fuel in seawater could improve its handling and removal. In this sense, pilot scale and eventually controlled in situ tests to study the feasibility of the proposed solution should be performed. (Author) 2 refs.

  14. Measurement of magnetic surfaces on the Compact Auburn Torsatron

    International Nuclear Information System (INIS)

    Henderson, M.A.; Gandy, R.F.; Hanson, J.D.; Knowlton, S.F.; Swanson, D.G.

    1992-01-01

    The magnetic flux surfaces of the Compact Auburn Torsatron have been experimentally mapped in a variety of magnetic configurations. The magnetic surface mapping was done using the phosphor screen technique. The results are compared with an extensive computer model in order to validate the design coil structure and determine what modifications are needed to correct any minor winding errors. In initial field mapping experiments, a large up--down asymmetry was identified in the vacuum magnetic surfaces. A set of mapping studies was used to characterize the error through addition of terms to the coil winding law. The error was corrected with the use of a radial trim coil

  15. Quantifying dust input to the Subarctic North Pacific - Results from surface sediments and sea water thorium isotope measurements

    Science.gov (United States)

    Winckler, G.; Serno, S.; Hayes, C.; Anderson, R. F.; Gersonde, R.; Haug, G. H.

    2012-12-01

    The Subarctic North Pacific is one of the three primary high-nutrient-low chlorophyll regions of the modern ocean, where the biological pump is relatively inefficient at transferring carbon from the atmosphere to the deep sea. The system is thought to be iron-limited. Aeolian dust is a significant source of iron and other nutrients that are essential for the health of marine ecosystems and potentially a controlling factor of the high-nutrient-low chlorophyll status of the Subarctic North Pacific. However, constraining the size of the dust flux to the surface ocean remains difficult. Here we apply two different approaches, based on surface sediment and water column samples, respectively, obtained during the SO202/INOPEX research cruise to the Subarctic North Pacific in 2009. We map the spatial patterns of Th/U isotopes, helium isotopes and rare earth elements across surface sediments from 37 multi-core core-top sediments across the Subarctic North Pacific. In order to deconvolve the detrital endmembers in regions of the North Pacific affected by volcanic material, IRD and hemipelagic input, we use a combination of trace elements with distinct characteristics in the different endmembers. This approach allows us to calculate the relative aeolian fraction, and in combination with Thorium230-normalized mass flux data, to quantify the dust supply. Secondly, we present an innovative approach to use paired Thorium-232 and Thorium-230 concentrations of upper-ocean seawater at 7 stations along the INOPEX track. Thorium-232 in the upper water column is dominantly derived from dissolution of aeolian dust, whereas Thorium-230 data provide a measure of the thorium removal from the surface waters and, thus, allow us to derive Thorium-232 fluxes. Combined with a mean Thorium-232 concentration in dust and estimate of the thorium solubility, the Thorium-232 flux can be translated in a dust flux to the surface ocean. Dust flux estimates for the Subarctic North Pacific will be

  16. Corrosion-free solar collectors for thermally driven seawater desalination

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, M.; Koschikowski, J.; Rommel, M. [Fraunhofer Inst. for Solar Energy Systems ISE, Freiburg (Germany)

    2000-07-01

    Seawater desalination can be carried out by a variety of techniques, some of which are thermally driven at operating temperatures in the range of 60 to 80 deg. C. At this temperature level, these systems can be supplied by thermal energy gained from solar collectors. In order to increase the efficiency of such systems and simultaneously reduce costs, a heat exchanger between the collector loop and the desalination unit can be omitted if the seawater flows directly through the collectors. Since hot seawater is very aggressive, this configuration requires corrosion-free solar collectors. We developed selectively coated prototype collectors which fulfil this requirement. They will be installed in a pilot plant in Pozo Izquierdo, Gran Canaria, which will produce about 600 litres of desalinated water per day. This international project is funded by the European Commission DG XII, within the JOULE programme. The main task was to find materials which are resistant to seawater and can withstand temperatures up to 200 deg. C, which can occur under stagnation conditions. Moreover, it had to be ensured that it was possible to apply a selective coating on the absorber in order to increase the efficiency. A further limitation was given by the aim for the resulting water costs. After investigating different materials and collector designs, we developed a prototype consisting of an array of selectively coated glass tubes mounted in a conventional flat-plate collector housing. The efficiency was increased by adding a specially shaped reflector. The design was developed by carrying out both various optical and thermal simulations and indoor as well as outdoor tests. We obtained an appropriate collector which fulfilled the technical and economical requirements set by the special task of desalinating seawater. In-situ measurements at the test site in Gran Canaria will be carried out to gain more information about the long-term collector performance. (au)

  17. Why seawater intrusion has not yet occurred in the Kaluvelli-Pondicherry basin, Tamil Nadu, India

    Science.gov (United States)

    Vincent, Aude; Violette, Sophie

    2017-09-01

    Worldwide, coastal aquifers are threatened by seawater intrusion. The threat is greatest when aquifers are overexploited or when recharge is low due to a semi-arid or arid climate. The Kaluvelli-Pondicherry sedimentary basin in Tamil Nadu (India) presents both these characteristics. Groundwater levels in the Vanur aquifer can reach 50 m below sea level at less than 20 km inland. This groundwater depletion is due to an exponential increase in extraction for irrigation over 35 years. No seawater intrusion has yet been detected, but a sulphate-rich mineralization is observed, the result of upward vertical leakage from the underlying Ramanathapuram aquifer. To characterize the mechanisms involved, and to facilitate effective water management, hydrogeological numerical modelling of this multi-layered system has been conducted. Existing and acquired geological and hydrodynamic data have been applied to a quasi-3D hydrogeological model, NEWSAM. Recharge had been previously quantified through the inter-comparison of hydrological models, based on climatological and surface-flow field measurements. Sensitivity tests on parameters and boundary conditions associated with the sea were performed. The resulting water balances for each aquifer led to hypotheses of (1) an offshore fresh groundwater stock, and (2) a reversal and increase of the upward leakage from the Ramanathapuram aquifer, thus corroborating the hypothesis proposed to explain geochemical results of the previous study, and denying a seawater intrusion. Palaeo-climate review supports the existence of favourable hydro-climatological conditions to replenish an offshore groundwater stock of the Vanur aquifer in the past. The extent of this fresh groundwater stock was calculated using the Kooi and Groen method.

  18. SMEX03 Surface and Soil Temperature Measurements: Alabama

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains land surface temperature and soil temperature data at depths of 1 cm, 5 cm, and 10 cm collected during the Soil Moisture Experiment 2003...

  19. Measuring the surface-heating of medical ultrasonic probes

    International Nuclear Information System (INIS)

    Kollmann, Chr; Vacariu, G; Fialka-Moser, V; Bergmann, H

    2004-01-01

    Due to converting losses the probe's surface itself is heated up, especially when emitting into air. Possible temperature increases in an ensemble of 15 different diagnostic and therapeutic ultrasound probes from 7 manufacturers in the frequency range between 0.05-7.5 MHz have been examined. Surface temperatures were detected by means of a calibrated IR-thermographic camera using a scheme of various power and pulse settings, as well as different imaging modalitites as used in clinical routine. Depending on the setup and the output power, the absolute surface temperatures of some of the probes emitting in air can be beyond 43 deg. C within 5-7 min.; a maximum surface temperature of 84 deg. C has been detected. Continuous mode or high pulse repetition frequencies on the therapeutic system side, small focused Doppler modes on the diagnostic system side combined with increased emitted acoustic intensities result in high surface temperatures. Within a worst case scenario a potential risk of negative skin changes (heat damage) or non-optimal therapeutic effects seems to be possible if a therapeutic system is used very often and if its emission continues unintentionally. In general the user should be aware that low emission intensities of e.g. 50 mW cm -2 could already produce hot surfaces

  20. Removal of Surface-Reflected Light for the Measurement of Remote-Sensing Reflectance from an Above-Surface Platform

    Science.gov (United States)

    2010-12-06

    REPORT DATE IDD-MM- YYYY) 14-02-2011 2. REPORT TYPE Journal Article 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Removal of Surface...impossible to obtain Rr, from measurements of vertical profiles of Lu and Elt [6]. During the experiment, the surface was calm [see Fig. 8(a)] and

  1. An AFM-based pit-measuring method for indirect measurements of cell-surface membrane vesicles

    International Nuclear Information System (INIS)

    Zhang, Xiaojun; Chen, Yuan; Chen, Yong

    2014-01-01

    Highlights: • Air drying induced the transformation of cell-surface membrane vesicles into pits. • An AFM-based pit-measuring method was developed to measure cell-surface vesicles. • Our method detected at least two populations of cell-surface membrane vesicles. - Abstract: Circulating membrane vesicles, which are shed from many cell types, have multiple functions and have been correlated with many diseases. Although circulating membrane vesicles have been extensively characterized, the status of cell-surface membrane vesicles prior to their release is less understood due to the lack of effective measurement methods. Recently, as a powerful, micro- or nano-scale imaging tool, atomic force microscopy (AFM) has been applied in measuring circulating membrane vesicles. However, it seems very difficult for AFM to directly image/identify and measure cell-bound membrane vesicles due to the similarity of surface morphology between membrane vesicles and cell surfaces. Therefore, until now no AFM studies on cell-surface membrane vesicles have been reported. In this study, we found that air drying can induce the transformation of most cell-surface membrane vesicles into pits that are more readily detectable by AFM. Based on this, we developed an AFM-based pit-measuring method and, for the first time, used AFM to indirectly measure cell-surface membrane vesicles on cultured endothelial cells. Using this approach, we observed and quantitatively measured at least two populations of cell-surface membrane vesicles, a nanoscale population (<500 nm in diameter peaking at ∼250 nm) and a microscale population (from 500 nm to ∼2 μm peaking at ∼0.8 μm), whereas confocal microscopy only detected the microscale population. The AFM-based pit-measuring method is potentially useful for studying cell-surface membrane vesicles and for investigating the mechanisms of membrane vesicle formation/release

  2. Measuring the role of seagrasses in regulating sediment surface elevation.

    Science.gov (United States)

    Potouroglou, Maria; Bull, James C; Krauss, Ken W; Kennedy, Hilary A; Fusi, Marco; Daffonchio, Daniele; Mangora, Mwita M; Githaiga, Michael N; Diele, Karen; Huxham, Mark

    2017-09-20

    Seagrass meadows provide numerous ecosystem services and their rapid global loss may reduce human welfare as well as ecological integrity. In common with the other 'blue carbon' habitats (mangroves and tidal marshes) seagrasses are thought to provide coastal defence and encourage sediment stabilisation and surface elevation. A sophisticated understanding of sediment elevation dynamics in mangroves and tidal marshes has been gained by monitoring a wide range of different sites, located in varying hydrogeomorphological conditions over long periods. In contrast, similar evidence for seagrasses is sparse; the present study is a contribution towards filling this gap. Surface elevation change pins were deployed in four locations, Scotland, Kenya, Tanzania and Saudi Arabia, in both seagrass and unvegetated control plots in the low intertidal and shallow subtidal zone. The presence of seagrass had a highly significant, positive impact on surface elevation at all sites. Combined data from the current work and the literature show an average difference of 31 mm per year in elevation rates between vegetated and unvegetated areas, which emphasizes the important contribution of seagrass in facilitating sediment surface elevation and reducing erosion. This paper presents the first multi-site study for sediment surface elevation in seagrasses in different settings and species.

  3. Measuring the role of seagrasses in regulating sediment surface elevation

    KAUST Repository

    Potouroglou, Maria

    2017-09-13

    Seagrass meadows provide numerous ecosystem services and their rapid global loss may reduce human welfare as well as ecological integrity. In common with the other \\'blue carbon\\' habitats (mangroves and tidal marshes) seagrasses are thought to provide coastal defence and encourage sediment stabilisation and surface elevation. A sophisticated understanding of sediment elevation dynamics in mangroves and tidal marshes has been gained by monitoring a wide range of different sites, located in varying hydrogeomorphological conditions over long periods. In contrast, similar evidence for seagrasses is sparse; the present study is a contribution towards filling this gap. Surface elevation change pins were deployed in four locations, Scotland, Kenya, Tanzania and Saudi Arabia, in both seagrass and unvegetated control plots in the low intertidal and shallow subtidal zone. The presence of seagrass had a highly significant, positive impact on surface elevation at all sites. Combined data from the current work and the literature show an average difference of 31 mm per year in elevation rates between vegetated and unvegetated areas, which emphasizes the important contribution of seagrass in facilitating sediment surface elevation and reducing erosion. This paper presents the first multi-site study for sediment surface elevation in seagrasses in different settings and species.

  4. The isotope composition of inorganic germanium in seawater and deep sea sponges

    Science.gov (United States)

    Guillermic, Maxence; Lalonde, Stefan V.; Hendry, Katharine R.; Rouxel, Olivier J.

    2017-09-01

    Although dissolved concentrations of germanium (Ge) and silicon (Si) in modern seawater are tightly correlated, uncertainties still exist in the modern marine Ge cycle. Germanium stable isotope systematics in marine systems should provide additional constraints on marine Ge sources and sinks, however the low concentration of Ge in seawater presents an analytical challenge for isotopic measurement. Here, we present a new method of pre-concentration of inorganic Ge from seawater which was applied to measure three Ge isotope profiles in the Southern Ocean and deep seawater from the Atlantic and Pacific Oceans. Germanium isotopic measurements were performed on Ge amounts as low as 2.6 ng using a double-spike approach and a hydride generation system coupled to a MC-ICP-MS. Germanium was co-precipitated with iron hydroxide and then purified through anion-exchange chromatography. Results for the deep (i.e. >1000 m depth) Pacific Ocean off Hawaii (nearby Loihi Seamount) and the deep Atlantic off Bermuda (BATS station) showed nearly identical δ74/70Ge values at 3.19 ± 0.31‰ (2SD, n = 9) and 2.93 ± 0.10‰ (2SD, n = 2), respectively. Vertical distributions of Ge concentration and isotope composition in the deep Southern Ocean for water depth > 1300 m yielded an average δ74/70Ge = 3.13 ± 0.25‰ (2SD, n = 14) and Ge/Si = 0.80 ± 0.09 μmol/mol (2SD, n = 12). Significant variations in δ74/70Ge, from 2.62 to 3.71‰, were measured in the first 1000 m in one station of the Southern Ocean near Sars Seamount in the Drake Passage, with the heaviest values measured in surface waters. Isotope fractionation by diatoms during opal biomineralization may explain the enrichment in heavy isotopes for both Ge and Si in surface seawater. However, examination of both oceanographic parameters and δ74/70Ge values suggest also that water mass mixing and potential contribution of shelf-derived Ge also could contribute to the variations. Combining these results with new Ge isotope data

  5. Optical Roughness Measuring Instrument For Fine-Machined Surfaces

    Science.gov (United States)

    Brodmann, Rainer; Gerstorfer, Oskar; Thurn, Gerd

    1985-06-01

    The roughness measuring instrument described is based on light scattering and is suitable in a wide range of applications, especially in micro-machining. The most important properties are the sensitivity in the measuring range from below 0.005 i.im up to 2µm (Ra value), the independence of the reflection coefficient due to normalization, and the larger tolerance of measur-ing distance of +/-2 mm.

  6. Calculation of the surface potential and surface charge density by measurement of the three-phase contact angle.

    Science.gov (United States)

    Horiuchi, H; Nikolov, A; Wasan, D T

    2012-11-01

    The silica/silicon wafer is widely used in the semiconductor industry in the manufacture of electronic devices, so it is essential to understand its physical chemistry and determine the surface potential at the silica wafer/water interface. However, it is difficult to measure the surface potential of a silica/silicon wafer directly due to its high electric resistance. In the present study, the three-phase contact angle (TPCA) on silica is measured as a function of the pH. The surface potential and surface charge density at the silica/water surface are calculated by a model based on the Young-Lippmann equation in conjunction with the Gouy-Chapman model for the electric double layer. In measurements of the TPCA on silica, two distinct regions were identified with a boundary at pH 9.5-showing a dominance of the surface ionization of silanol groups below pH 9.5 and a dominance of the dissolution of silica into the aqueous solution above pH 9.5. Since the surface chemistry changes above pH 9.5, the model is applied to solutions below pH 9.5 (ionization dominant) for the calculation of the surface potential and surface charge density at the silica/aqueous interface. In order to evaluate the model, a galvanic mica cell was made of a mica sheet and the surface potential was measured directly at the mica/water interface. The model results are also validated by experimental data from the literature, as well as the results obtained by the potentiometric titration method and the electro-kinetic measurements. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Linkage between seasonal insolation gradient in the tropical northern hemisphere and the sea surface salinity of the equatorial Indian Ocean during the last glacial period

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.; Nigam, R.; Mackensen, A.; Weldeab, S.

    oxygen isotopic composition to estimate the local seawater oxygen isotopic composition (δ18Osw-ivc). The change in δ18Osw-ivc relative to the present day value (∆δ18Osw-ivc) was then calculated by subtracting the modern surface seawater oxygen isotopic... the modern measurement (Fig. 5), match very well with the Levitus 7 annual SSS over the core site, showing values of 34.7 and 34.8, respectively. Delaygue et al (2001) also developed a seawater oxygen isotope/salinity relationship for the Bay of Bengal...

  8. Measuring of noise and wearing of quiet surfaces

    OpenAIRE

    Raitanen, Nina

    2005-01-01

    When using surfaces with special qualities, there is a need for tools to assess these qualities. Two methods, SPB (Statistical Pass-by) and CPX (Close Proximity), have been used for testing the noise properties of the surfaces in the other countries. Both of these methods had to be modified to suit the Finnish environment. SPBmod-method adheres to the ISO-standard quite closely. It was decided that heavy vehicles are not included in the test, as stipulated in the standard. The normalisation s...

  9. Present status of uranium extraction from seawater

    International Nuclear Information System (INIS)

    Kusakabe, Katsuki; Morooka, Shigeharu

    1993-01-01

    For the research on the extraction of uranium from seawater, various processes have been examined, but the most promising process is adsorption. Its key point is the performance of the adsorbent. The system as compact as possible, in which a large quantity of seawater effectively contacts with the adsorbent, must be constructed economically. As the inorganic adsorbent, titanium oxide is the best, but organic amidoxime is superior to it. The present state of the development of the adsorbent, the rate of adsorption of the adsorbenbt, the seawater uranium adsorption system and the experiment in Imari Bay are reported. (K.I.)

  10. Surface Catalysis and Oxidation on Stagnation Point Heat Flux Measurements in High Enthalpy Arc Jets

    Science.gov (United States)

    Nawaz, Anuscheh; Driver, David M.; Terrazas-Salinas

    2013-01-01

    Heat flux sensors are routinely used in arc jet facilities to determine heat transfer rates from plasma plume. The goal of this study is to assess the impact of surface composition changes on these heat flux sensors. Surface compositions can change due to oxidation and material deposition from the arc jet. Systematic surface analyses of the sensors were conducted before and after exposure to plasma. Currently copper is commonly used as surface material. Other surface materials were studied including nickel, constantan gold, platinum and silicon dioxide. The surfaces were exposed to plasma between 0.3 seconds and 3 seconds. Surface changes due to oxidation as well as copper deposition from the arc jets were observed. Results from changes in measured heat flux as a function of surface catalycity is given, along with a first assessment of enthalpy for these measurements. The use of cupric oxide is recommended for future heat flux measurements, due to its consistent surface composition arc jets.

  11. Surface adhesion and its dependence on surface roughness and humidity measured with a flat AFM tip

    NARCIS (Netherlands)

    Colak, A.; Wormeester, Herbert; Zandvliet, Henricus J.W.; Poelsema, Bene

    2012-01-01

    The adhesion force between a surface and the tip of an atomic force microscope cantilever has been determined by recording force–distance curves with an atomic force microscope. Flat tips with a diameter of 2 μm were used to mimic the adhesion between two parallel surfaces. In such a configuration,

  12. Oxidation of clean silicon surfaces studied by four-point probe surface conductance measurements

    DEFF Research Database (Denmark)

    Petersen, Christian Leth; Grey, Francois; Aono, M.

    1997-01-01

    We have investigated how the conductance of Si(100)-(2 x 1) and Si(111)-(7 x 7) surfaces change during exposure to molecular oxygen. A monotonic decrease in conductance is seen as the (100) surfaces oxidizes. In contract to a prior study, we propose that this change is caused by a decrease in sur...

  13. Leidenfrost drops cooling surfaces: theory and interferometric measurement

    NARCIS (Netherlands)

    Van Limbeek, Michiel A. J.; Klein Schaarsberg, Martin H.; Sobac, Benjamin; Rednikov, Alexey; Sun, Chao; Colinet, Pierre; Lohse, Detlef

    2017-01-01

    When a liquid drop is placed on a highly superheated surface, it can be levitated by its own vapour. This remarkable phenomenon is referred to as the Leidenfrost effect. The thermally insulating vapour film results in a severe reduction of the heat transfer rate compared to experiments at lower

  14. Measurement of grassland evaporation using a surface-layer ...

    African Journals Online (AJOL)

    A dual-beam surface-layer scintillometer (SLS) was used to estimate sensible heat flux (H) every 2 min for a path length of either 50 or 101 m, for more than 30 months in a mesic grassland in eastern South Africa. The SLS method relies on Monin-Obukhov similarity theory, the correlation between the laser beam signal ...

  15. Numerical modeling of seawater flow through the flooding system of dry docks

    Directory of Open Access Journals (Sweden)

    A. Najafi-Jilani

    2009-12-01

    Full Text Available Numerical simulations have been carried out on the flooding system of a dry dock in design stage and to be located at the south coasts of Iran. The main goals of the present investigation are to evaluate the flooding time as well as the seawater flow characteristics in the intake channels of the dock. The time dependent upstream and downstream boundary conditions of the flooding system are imposed in the modeling. The upstream boundary condition is imposed in accordance with the tidal fluctuations of sea water level. At the downstream, the gradually rising water surface elevation in the dry dock is described in a transient boundary condition. The numerical results are compared with available laboratory measured data and a good agreement is obtained. The seawater discharge through the flooding system and the required time to filling up the dry dock is determined at the worst case. The water current velocity and pressure on the rigid boundaries are also calculated and discussed.

  16. Surface and Flow Field Measurements on the FAITH Hill Model

    Science.gov (United States)

    Bell, James H.; Heineck, James T.; Zilliac, Gregory; Mehta, Rabindra D.; Long, Kurtis R.

    2012-01-01

    A series of experimental tests, using both qualitative and quantitative techniques, were conducted to characterize both surface and off-surface flow characteristics of an axisymmetric, modified-cosine-shaped, wall-mounted hill named "FAITH" (Fundamental Aero Investigates The Hill). Two separate models were employed: a 6" high, 18" base diameter machined aluminum model that was used for wind tunnel tests and a smaller scale (2" high, 6" base diameter) sintered nylon version that was used in the water channel facility. Wind tunnel and water channel tests were conducted at mean test section speeds of 165 fps (Reynolds Number based on height = 500,000) and 0.1 fps (Reynolds Number of 1000), respectively. The ratio of model height to boundary later height was approximately 3 for both tests. Qualitative techniques that were employed to characterize the complex flow included surface oil flow visualization for the wind tunnel tests, and dye injection for the water channel tests. Quantitative techniques that were employed to characterize the flow included Cobra Probe to determine point-wise steady and unsteady 3D velocities, Particle Image Velocimetry (PIV) to determine 3D velocities and turbulence statistics along specified planes, Pressure Sensitive Paint (PSP) to determine mean surface pressures, and Fringe Imaging Skin Friction (FISF) to determine surface skin friction (magnitude and direction). This initial report summarizes the experimental set-up, techniques used, data acquired and describes some details of the dataset that is being constructed for use by other researchers, especially the CFD community. Subsequent reports will discuss the data and their interpretation in more detail

  17. Cardiorespiratory upregulation during seawater acclimation in rainbow trout: effects on gastrointestinal perfusion and postprandial responses.

    Science.gov (United States)

    Brijs, Jeroen; Gräns, Albin; Ekström, Andreas; Olsson, Catharina; Axelsson, Michael; Sandblom, Erik

    2016-05-01

    Increased gastrointestinal blood flow is essential for euryhaline fishes to maintain osmotic homeostasis during the initial phase of a transition from freshwater to seawater. However, the cardiorespiratory responses and hemodynamic changes required for a successful long-term transition to seawater remain largely unknown. In the present study, we simultaneously measured oxygen consumption rate (ṀO2), cardiac output (CO), heart rate (HR), and gastrointestinal blood flow (GBF) in rainbow trout (Oncorhynchus mykiss) acclimated to either freshwater or seawater for at least 6 wk. Seawater-acclimated trout displayed significantly elevated ṀO2 (day: 18%, night: 19%), CO (day: 22%, night: 48%), and GBF (day: 96%, night: 147%), demonstrating that an overall cardiorespiratory upregulation occurs during seawater acclimation. The elevated GBF was achieved via a combination of increased CO, mediated through elevated stroke volume (SV), and a redistribution of blood flow to the gastrointestinal tract. Interestingly, virtually all of the increase in CO of seawater-acclimated trout was directed to the gastrointestinal tract. Although unfed seawater-acclimated trout displayed substantially elevated cardiorespiratory activity, the ingestion of a meal resulted in a similar specific dynamic action (SDA) and postprandial GBF response as in freshwater-acclimated fish. This indicates that the capacity for the transportation of absorbed nutrients, gastrointestinal tissue oxygen delivery, and acid-base regulation is maintained during digestion in seawater. The novel findings presented in this study clearly demonstrate that euryhaline fish upregulate cardiovascular function when in seawater, while retaining sufficient capacity for the metabolic and cardiovascular changes associated with the postprandial response. Copyright © 2016 the American Physiological Society.

  18. Determination of picomolar beryllium levels in seawater with inductively coupled plasma mass spectrometry following silica-gel preconcentration

    International Nuclear Information System (INIS)

    Tazoe, Hirofumi; Yamagata, Takeyasu; Obata, Hajime; Nagai, Hisao

    2014-01-01

    Highlights: • We developesd the simplest and robust SPE method for ultra low picomolar level beryllium in seawater. • Just silica gel column can quantitatively adsorb beryllium in neutral pH condition containing natural seawater. • EDTA solution can eliminate seawater matrixes retaining Be in the column, which optimize to ICP-MS detemination. • Accurate and precise Be data have been obtained for natural seawater from North Pacific Ocean. - Abstract: A robust and rapid method for the determination of natural levels of beryllium (Be) in seawater was developed to facilitate mapping Be concentrations in the ocean. A solid-phase extraction method using a silica gel column was applied for preconcentration and purification of Be in seawater prior to determination of Be concentrations with inductively coupled plasma mass spectrometry (ICP-MS). Be was quantitatively adsorbed onto silica gel from solutions with pH values ranging from 6.3 to 9, including natural seawater. The chelating agent ethylenediamine tetraacetic acid was used to remove other ions in the seawater matrix (Na, Mg, and Ca) that interfere with the ICP-MS analysis. The reproducibility of the method was 3% based on triplicate analyses of natural seawater samples, and the detection limit was 0.4 pmol kg −1 for 250 mL of seawater, which is sufficient for the analysis of seawater in the open ocean. The method was then used to determine the vertical profile of Be in the eastern North Pacific Ocean, which was found to be a recycled-type profile in which the Be concentration increased with depth from the surface (7.2 pmol kg −1 at <200 m) to deep water (29.2 pmol kg −1 from 3500 m to the bottom)

  19. The Separation and Isotopic Analysis Seawater Cu and Zn

    Science.gov (United States)

    Bermin, J.; Vance, D.; Archer, C.; Statham, P. J.

    2004-12-01

    Many transition metals are key micronutrients and their concentration profiles in the oceans often show nutrient-like patterns, with strong surface depletions and deep enrichments1. In addition, their biological usage has been shown to induce isotopic fractionations2 so that the precise and accurate analysis of their isotope systems in seawater has potential applications in tracing metal micronutrient usage in the past ocean. The analytical challenges involved in realising this goal are, however, considerable, given the low concentrations of transition metals in seawater and the requirement to extract small amounts from large samples at low blank and with no artificial isotopic fractionation. Here we present a method for the separation an analysis of Cu and Zn isotopes that is applicable to 0.1-5 L samples of seawater. Trace metals were concentrated from seawater using a Chelex-100 ion-exchange column3 and further purified and separated from each other using a small anion column4,5. All isotopic analyses were performed on a ThermoFinnigan Neptune instrument at the University of Bristol. The main requirements for precise and accurate isotopic analyses are a low contribution from analytical blank and the robust correction for analytical mass discrimination. Our blanks allow the analysis of seawater samples of 50-250 mL for Cu, samples of about 100 mL for Zn in the deep oceans and for Zn-depleted open ocean surface water samples of around 5L. The correction for mass discrimination is most readily considered as two components - that occurring during the chemical separation procedure in response to non-100% yields and that occurring in the mass spectrometer. Correction of all mass discrimination throughout the procedure is most robustly done for Zn and Fe using a double-spike that is added prior to any chemical treatment. This approach has been tested using standard-doped seawater samples that had previously been stripped of their metal contents using the Chelex column

  20. Surface-source modeling and estimation using biomagnetic measurements.

    Science.gov (United States)

    Yetik, Imam Samil; Nehorai, Arye; Muravchik, Carlos H; Haueisen, Jens; Eiselt, Michael

    2006-10-01

    We propose a number of electric source models that are spatially distributed on an unknown surface for biomagnetism. These can be useful to model, e.g., patches of electrical activity on the cortex. We use a realistic head (or another organ) model and discuss the special case of a spherical head model with radial sensors resulting in more efficient computations of the estimates for magnetoencephalography. We derive forward solutions, maximum likelihood (ML) estimates, and Cramér-Rao bound (CRB) expressions for the unknown source parameters. A model selection method is applied to decide on the most appropriate model. We also present numerical examples to compare the performances and computational costs of the different models and illustrate when it is possible to distinguish between surface and focal sources or line sources. Finally, we apply our methods to real biomagnetic data of phantom human torso and demonstrate the applicability of them.

  1. Measurement noise of a point autofocus surface topography instrument

    DEFF Research Database (Denmark)

    Feng, Xiaobing; Quagliotti, Danilo; Maculotti, Giacomo

    Optical instruments for areal topography measurement can be especially sensitive to noise when scanning is required. Such noise has different sources, including those internally generated and external sources from the environment.......Optical instruments for areal topography measurement can be especially sensitive to noise when scanning is required. Such noise has different sources, including those internally generated and external sources from the environment....

  2. Comparison of coral δ18O with pseudocorals derived from in situ sea surface salinity and temperature measurements

    Science.gov (United States)

    DeLong, K. L.; Chaichi, N.; Maupin, C. R.; Richey, J. N.; Quinn, T. M.; Poore, R. Z.

    2015-12-01

    Paleoclimatologists use pseudocorals and forward modeling of coral oxygen isotopes (δ18O) to assess δ18O variations for comparison with climate model output in order to understand past tropical oceanic-atmospheric variability. Oxygen isotopic (δ18Ocoral) variability in shallow water coral skeletons is dependent on sea surface temperature (SST) and δ18O of seawater (δ18Osw), which varies with sea surface salinity (SSS). However, measurements of δ18Osw and SSS are sparse; therefore, simulated SSS (e.g., SODA) is typically used in pseudocoral investigations. Our study site is the Dry Tortugas National Park (DRTO; 24º42'N, 82º48'W) in the southeastern Gulf of Mexico (GOM) where hourly SST and SSS measurements are available from NOAA buoys (1992-2002) and the Florida Keys National Marine Sanctuary (FKNMS; 2011-2014). Here we use bivariate forward modeling of monthly average buoy SSS and SST to develop a time series of pseudocoral δ18O (δ18Op = -0.22(‰/ºC)SST + 0.11(‰/psu)SSS) for DRTO that are compared with δ18Ocoral variations from three Siderastrea siderea coral colonies growing in close proximity within the park. We use the relationship for δ18Osw and SSS determined for Flower Garden Banks coral reef in the northern GOM (27º52'N, 93º49'W) since no measurements of δ18Osw are currently available for DRTO. δ18Op co-varies with δ18Ocoral (r2 = 0.59) with a root mean square error (RMSE = 0.32‰) greater than the intercolony δ18Ocoral variability (r2 = 0.80; RSME = 0.07‰). Discrepancies between δ18Op and δ18Ocoral may be related to the lack of a local SSS-δ18Osw relationship for DRTO or uncertainties in subannual time assignment for δ18Ocoral. A new source of SSS is the NASA satellite Aquarius (2012-2014), which may be useful in future pseudocoral studies, that is evaluated along with high resolution simulated SSS (Global Ocean Physics Reanalysis GLORYS2V3; 1993-2012). We find similar correlation between Aquarius-derived SSS and FKNMS SSS (r2

  3. Seawater circulating system in an aquaculture laboratory

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ingole, B.S.; Parulekar, A.H.

    The note gives an account, for the first time in India, of an Aquaculture Laboratory with open type seawater circulating system developed at the National Institute of Oceanography, Goa, India. Besides describing the details of the system...

  4. Experimental studies on urea degradation in seawater

    Digital Repository Service at National Institute of Oceanography (India)

    Rajendran, A.; Joseph, T.; Reddy, C.V.G.

    The rate of urea degradation in seawater was studied under various conditions and the kinetics of urea degradation was evaluated. Urea decomposition experiments showed that the rates and quantity of ammonium oxidation were slower in the relatively...

  5. Integration of thermal energy and seawater desalination

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Runya; Lin, Hu [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Xie, Lixin; Liu, Jie [School of Chemical Engineering and technology, Tianjin University, Tianjin 300072 (China); Han, Wei [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100080 (China)

    2010-11-15

    Energy and freshwater shortage are the bottlenecks restricting China's economic development. The integration of energy utilization system and seawater desalination is considered as an innovative technology enabling efficient simultaneous use of middle or low temperature thermal energy and supply freshwater. Three feasible approaches to integrate seawater desalination with energy utilization system are presented in this paper, including combinations of the desalination process with a Combined Cooling Heating and Power system (CCHP), a power plant, or a solar thermal utilization system. In addition, the feasibility and advantages of a seawater desalination system combined with a power plant are described. The findings indicate that combining seawater desalination with industrial processes is a feasible and promising way to solve the problems of the lack of freshwater and low efficient use of low temperature thermal energy in coastland areas. (author)

  6. Uranium preconcentration from seawater using adsorptive membranes

    International Nuclear Information System (INIS)

    Das, Sadananda; Pandey, A.K.; Manchanda, V.K.; Athawale, A.A.

    2009-01-01

    Uranium recovery from bio-aggressive but lean feed like seawater is a challenging problem as it requires in situ preconcentration of uranium in presence of huge excess of competing ions with fast sorption kinetics. In our laboratory, widely used amidoxime membrane (AO-membrane) was evaluated for uranium sorption under seawater conditions. This study indicated that AO-membrane was inherently slow because of the complexation chemistry involved in transfer of U(VI) from (UO 2 (CO 3 ) 3 ) 4 - to AO sites in membrane. In order to search better options, several chemical compositions of membrane were scanned for their efficacy for uranium preconcentration from seawater, and concluded that EGMP-membrane offers several advantages over AO-membrane. In this paper, the comparison of EGMP-membrane with AO-membrane for uranium sorption under seawater conditions has been reviewed. (author)

  7. The effect of scattered light sensor orientation on roughness measurement of curved polished surfaces

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

    2014-01-01

    Light scattering is a method for surface roughness measurements well suitable for use in a production environment thanks to its fast measurement rate, insensitivity to vibrations and to small misalignments. The method is however affected by several other factors. In this paper, the effect of angu...... of angular orientation of a commercial scattered light sensor on roughness measurements of polished cylindrical surfaces with crossed surface lay is investigated to document the robustness of the method....

  8. Measurement of the surface susceptibility and the surface conductivity of atomically thin by spectroscopic ellipsometry

    KAUST Repository

    Jayaswal, Gaurav

    2017-10-01

    We show how to correctly extract from the ellipsometric data the surface susceptibility and the surface conductivity that describe the optical properties of monolayer $\\ m MoS_2$. Theoretically, these parameters stem from modelling a single-layer two-dimensional crystal as a surface current, a truly two-dimensional model. Currently experimental practice is to consider this model equivalent to a homogeneous slab with an effective thickness given by the interlayer spacing of the exfoliating bulk material. We prove that the error in the evaluation of the surface susceptibility of monolayer $\\ m MoS_2$, owing to the use of the slab model, is at least 10% or greater, a significant discrepancy in the determination of the optical properties of this material.

  9. Extracting Minerals from Seawater: An Energy Analysis

    OpenAIRE

    Bardi, U.

    2010-01-01

    The concept of recovering minerals from seawater has been proposed as a way of counteracting the gradual depletion of conventional mineral ores. Seawater contains large amounts of dissolved ions and the four most concentrated metal ones (Na, Mg, Ca, K) are being commercially extracted today. However, all the other metal ions exist at much lower concentrations. This paper reports an estimate of the feasibility of the extraction of these metal ions on the basis of the energy needed. In most cas...

  10. Greening Drylands with Seawater Easily and Naturally.

    Science.gov (United States)

    Moustafa, Khaled

    2017-03-01

    The sun and sea are inexhaustible sources of energy and water that could be used to transform drylands into more viable ecosystems. A sustainable and cost-effective approach is proposed for greening drylands and restoring wildlife and biodiversity in deserts using seawater desert-houses (or movable seawater ponds) that could offer important environmental advantages. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Commencement measurements giving fundamental surface tension determinations in tensiometry

    International Nuclear Information System (INIS)

    Carbery, D; Morrin, D; O'Rourke, B; McMillan, N D; O'Neill, M; Riedel, S; Pringuet, P; Smith, S R P

    2011-01-01

    This study provides experimental testing of a ray-tracing model of the tensiotrace that explores the measurement potential of a well-defined optical position in the tensiotrace signal known as the 'commencement'. This point is defined as the first measureable optical coupling in the fiber drophead between source and collector fibers for light injected inside a growing drop. Tensiotrace ray-tracing model is briefly introduced. Empirical relationships of commencement measures from a wide-ranging study are presented. A number of conclusions can be drawn from the successful linking of computer predictions to these experimental relationships.

  12. Surface preparation for residual stress measurement of an accelerated corrosion tested welded marine steel

    International Nuclear Information System (INIS)

    Ahmad, Bilal; Fitzpatrick, Michael E.

    2015-01-01

    Residual stress measurement is often required for the assessment of structural integrity of components. Measurement of residual stress in corrosion tested specimens is challenging owing to the difficulty of accessing the surface because of the rust layer. This study explored the potential methods for the surface preparation of an ultrasonically-peened and accelerated corrosion tested DH36 marine steel fillet welded specimen to ease the way for subsequent residual stress measurement using neutron diffraction and the contour method. We find that hydroblasting introduces compressive residual stress at the surface that will alter the surface stress to be measured

  13. Surface roughness: A review of its measurement at micro-/nano-scale

    Science.gov (United States)

    Gong, Yuxuan; Xu, Jian; Buchanan, Relva C.

    2018-01-01

    The measurement of surface roughness at micro-/nano-scale is of great importance to metrological, manufacturing, engineering, and scientific applications given the critical roles of roughness in physical and chemical phenomena. The surface roughness of materials can significantly change the way of how they interact with light, phonons, molecules, and so forth, thus surface roughness ultimately determines the functionality and property of materials. In this short review, the techniques of measuring micro-/nano-scale surface roughness are discussed with special focus on the limitations and capabilities of each technique. In addition, the calculations of surface roughness and their theoretical background are discussed to offer readers a better understanding of the importance of post-measurement analysis. Recent progress on fractal analysis of surface roughness is discussed to shed light on the future efforts in surface roughness measurement.

  14. Seasonal Levels of the Vibrio Predator Bacteriovorax in Atlantic, Pacific, and Gulf Coast Seawater

    Directory of Open Access Journals (Sweden)

    Gary P. Richards

    2013-01-01

    Full Text Available Bacteriovorax were quantified in US Atlantic, Gulf, and Pacific seawater to determine baseline levels of these predatory bacteria and possible seasonal fluctuations in levels. Surface seawater was analyzed monthly for 1 year from Kailua-Kona, Hawaii; the Gulf Coast of Alabama; and four sites along the Delaware Bay. Screening for Bacteriovorax was performed on lawns of V. parahaemolyticus host cells. Direct testing of 7.5 mL portions of seawater from the Atlantic, Pacific, and Gulf coasts gave mean annual counts ≤12.2 PFU. Spikes in counts were observed at 3 out of 4 sites along the Delaware Bay 1 week after Hurricane Sandy. A comparison of summer versus winter counts showed significantly more Bacteriovorax (P≤0.0001 in the Delaware Bay during the summer and significantly more (P≤0.0001 in the Gulf during the winter, but no significant seasonal differences (P>0.05 for Hawaiian seawater. Bacteriovorax counts only correlated with seawater salinity and temperature at one Delaware site (r=0.79 and r=0.65, resp.. There was a relatively strong negative correlation between temperature and Bacteriovorax levels (r=−0.585 for Gulf seawater. Selected isolates were sequenced and identified by phylogenetic analysis as Bacteriovorax clusters IX, X, XI, and XII.

  15. Studies on rare earth elements in seawater and uptake by marine organisms

    International Nuclear Information System (INIS)

    Suzuki, H.; Koyanagi, T.; Saiki, M.

    1975-01-01

    The contents of rare earth elements in marine environmental samples were determined by neutron activation analysis to examine the existing state in coastal seawater and the concentration by marine organisms of the elements. Seawater was filtered through a Millipore filter GS (pore size 0.22 μm), before the analysis. Some of the seawater was treated with HC1 solution before filtration and some after filtration. Certain marine organisms were also analysed for determination of rare earth elements. These were: flounder (Paralichthys olivaceus); yellowtails (Seriola quinqueradiata); immature anchovy (Engraulis japonica); clams (Meretrix lusoria); green algae (Ulva pertusa); brown algae (Hizikia fusiforme, Sargassum fulvellum, Undaria pinnatifida). In the seawater without HC1 treatment before filtration, considerable amounts of the elements existed in residue on the filter, whereas in the seawater treated with HC1 before filtration, the greater part remained in the dissolved state. Concentration factors calculated from the contents of stable elements, therefore, are affected remarkably by the existing state of the elements in seawater. If only the dissolved state is assumed available for marine organisms, values one order higher are attained compared with the case where total amounts of the elements were used for the calculation. However, the contribution of the insoluble state seems to be not negligible with some organisms. The higher concentration factors for immature anchovy and clams observed in this study were considered to be caused by surface adsorption of elements in particulate form and also ingested sediment with high element concentration. (author)

  16. Time-Resolved Surface Temperature Measurement for Pulsed Ablative Thrusters

    National Research Council Canada - National Science Library

    Antonsen, Erik

    2003-01-01

    .... The diagnostic draws on heritage from the experimental dynamic crack propagation community which has used photovoltaic infrared detectors to measure temperature rise in materials in the process of fracture...

  17. Earth System Research Laboratory Long-Term Surface Aerosol Measurements

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aerosol measurements began at the NOAA Earth System Research Laboratory (ESRL) Global Monitoring Division (GMD) baseline observatories in the mid-1970's with the...

  18. Secular variation in the major-ion chemistry of seawater: Evidence from fluid inclusions in Cretaceous halites

    Science.gov (United States)

    Timofeeff, Michael N.; Lowenstein, Tim K.; da Silva, Maria Augusta Martins; Harris, Nicholas B.

    2006-04-01

    The major-ion (Mg 2+, Ca 2+, Na +, K +, SO42-, and Cl -) chemistry of Cretaceous seawater was determined from analyses of seawater-derived brines preserved as fluid inclusions in marine halites. Fluid inclusions in primary halite from three evaporite deposits were analyzed by the environmental scanning electron microscopy (ESEM) X-ray energy dispersive spectrometry (EDS) technique: the Early Cretaceous (Aptian, 121.0-112.2 Ma) of the Sergipe basin, Brazil and the Congo basin, Republic of the Congo, and the Early to Late Cretaceous (Albian to Cenomanian, 112.2-93.5 Ma) of the Khorat Plateau, Laos, and Thailand. The fluid inclusions in halite indicate that Cretaceous seawater was enriched several fold in Ca 2+, depleted in SO42-, Na +, and Mg 2+, and had lower Na +/Cl -, Mg 2+/Ca 2+, and Mg 2+/K + ratios compared to modern seawater. Elevated Ca 2+ concentrations, with Ca 2+ > SO42- at the point of gypsum saturation, allowed Cretaceous seawater to evolve into Mg 2+-Ca 2+-Na +-K +-Cl - brines lacking measurable SO42-.The major-ion composition of Cretaceous seawater was modeled from fluid inclusion chemistries for the Aptian and the Albian-Cenomanian. Aptian seawater was extreme in its Ca 2+ enrichment, more than three times higher than present day seawater, with a Mg 2+/Ca 2+ ratio of 1.1-1.3. Younger, Albian-Cenomanian seawater had lower Ca 2+ concentrations, and a higher Mg 2+/Ca 2+ ratio of 1.2-1.7. Cretaceous (Aptian) seawater has the lowest Mg 2+/Ca 2+ ratios so far documented in Phanerozoic seawater from fluid inclusions in halite, and within the range chemically favorable for precipitation of low-Mg calcite ooids and cements. Results from halite fluid inclusions, together with Mg 2+/Ca 2+ ratios measured from echinoderm and rudist calcite, all indicate that Early Cretaceous seawater (Hauterivian, Barremian, Aptian, and Albian) had lower Mg 2+/Ca 2+ ratios than Late Cretaceous seawater (Coniacian, Santonian, and Campanian). Low Aptian-Albian Mg 2+/Ca 2+ seawater

  19. Effect of seawater environmental exposure on fatigue properties of polyethylene pipe

    Energy Technology Data Exchange (ETDEWEB)

    Tipton, D G

    1980-10-01

    One laboratory study at NIT was reported to show an unexpected decrease in crystallinity for a polyethylene material exposed to fatigue loading in a synthetic seawater solution. High density polyethylene Sclairpipe, from the OTEC-1 cold water pipe, was evaluated for resistance to corrosion fatigue in natural seawater. Intermediate crystallinity measurements (via bulk density) showed no effect of corrosion fatigue exposure. Heat of fusion (a relative indicator of crystallinity) also showed no effect of the exposure. Seawater exposure produced no significant change in tensile strength. One failure was observed during the corrosion fatigue tests and was attributed to porosity observed by fractography. These data suggest that high density polyethylene is not significantly sensitive to degradation of fatigue strength in natural seawater.

  20. Performance verification of focus variation and confocal microscopes measuring tilted ultra-fine surfaces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Baruffi, Federico; Tosello, Guido

    2016-01-01

    The behaviour of two optical instruments, scilicet a laser scanning confocal microscope and a focus-variation microscope, was investigated considering measurements of tilted surfaces. The measured samples were twelve steel artefacts for mould surface finish reference, covering Sa roughness...... parameter in the range (101—103) nm. The 3D surface texture parameters considered were Sa, Sq and Sdq. The small working distance of the confocal microscope objectives influenced the measurement setup, preventing from selecting a high tilting angle. The investigation was carried out comparing measurements...... of flat surfaces (0° tilt) with measurements of 12.5° tilted surfaces. The confocal microscope results showed a high sensitivity to tilting due to the laser beam reflection on the metal surfaces. The focus variation microscope results were more robust with respect to the considered angular variation...

  1. Sea level: measuring the bounding surfaces of the ocean.

    Science.gov (United States)

    Tamisiea, Mark E; Hughes, Chris W; Williams, Simon D P; Bingley, Richard M

    2014-09-28

    The practical need to understand sea level along the coasts, such as for safe navigation given the spatially variable tides, has resulted in tide gauge observations having the distinction of being some of the longest instrumental ocean records. Archives of these records, along with geological constraints, have allowed us to identify the century-scale rise in global sea level. Additional data sources, particularly satellite altimetry missions, have helped us to better identify the rates and causes of sea-level rise and the mechanisms leading to spatial variability in the observed rates. Analysis of all of the data reveals the need for long-term and stable observation systems to assess accurately the regional changes as well as to improve our ability to estimate future changes in sea level. While information from many scientific disciplines is needed to understand sea-level change, this review focuses on contributions from geodesy and the role of the ocean's bounding surfaces: the sea surface and the Earth's crust. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  2. Sea level: measuring the bounding surfaces of the ocean

    Science.gov (United States)

    Tamisiea, Mark E.; Hughes, Chris W.; Williams, Simon D. P.; Bingley, Richard M.

    2014-01-01

    The practical need to understand sea level along the coasts, such as for safe navigation given the spatially variable tides, has resulted in tide gauge observations having the distinction of being some of the longest instrumental ocean records. Archives of these records, along with geological constraints, have allowed us to identify the century-scale rise in global sea level. Additional data sources, particularly satellite altimetry missions, have helped us to better identify the rates and causes of sea-level rise and the mechanisms leading to spatial variability in the observed rates. Analysis of all of the data reveals the need for long-term and stable observation systems to assess accurately the regional changes as well as to improve our ability to estimate future changes in sea level. While information from many scientific disciplines is needed to understand sea-level change, this review focuses on contributions from geodesy and the role of the ocean's bounding surfaces: the sea surface and the Earth's crust. PMID:25157196

  3. Anodic Dissolution of API X70 Pipeline Steel in Arabian Gulf Seawater after Different Exposure Intervals

    Directory of Open Access Journals (Sweden)

    El-Sayed M. Sherif

    2014-01-01

    Full Text Available The anodic dissolution of API X70 pipeline steel in Arabian Gulf seawater (AGSW was investigated using open-circuit potential (OCP, electrochemical impedance spectroscopy (EIS, cyclic potentiodynamic polarization (CPP, and current-time measurements. The electrochemical experiments revealed that the X70 pipeline steel suffers both general and pitting corrosion in the AGSW solution. It was found that the general corrosion decreases as a result of decreasing the corrosion current density (jcorr, corrosion rate (Rcorr and absolute currents as well as the increase of polarization resistance of X70 with increasing the exposure time. On the other hand, the pitting corrosion was found to increase with increasing the immersion time. This was confirmed by the increase of current with time and by the SEM images that were obtained on the steel surface after 20 h immersion before applying an amount of 0–.35 V versus Ag/AgCl for 1 h.

  4. Measurement of the interaction between the flow and the free surface of a liquid

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Koji [Univ. of Tokyo, Ibaraki (Japan); Schmidl, W.D.; Philip, O.G. [Texas A& M Univ., College Station, TX (United States)

    1995-09-01

    The interaction between the flow and free surface was evaluated measuring the velocity distribution and surface movement simultaneously. The test section was a rectangular tank having a free surface. A rectangular nozzle was set near the free surface, causing the wavy free surface condition. The flow under the free surface was visualized by a laser light sheet and small tracer particles. With image processing techniques, the movement of the free surface and the movement of the particles were simultaneously measured from the recorded images, resulting in the velocity distributions and surface locations. Then, the interactions between the flow and free surface were evaluated using the form of turbulent energy and surface-related turbulent values. By increasing the turbulent energy near the free surface, the fluctuations of the free surface height and the inclination of the free surface were increased. The higher fluctuation of horizontal velocity was related to the higher surface position and negative inclination. The image processing technique is found to be very useful to evaluate the interaction between free surface and flow.

  5. High-speed 3D surface measurement with mechanical projector

    Science.gov (United States)

    Hyun, Jae-Sang; Zhang, Song

    2017-05-01

    This paper presents a method to overcome the light spectral range limitation of using digital-light-processing (DLP) projector for 3D shape measurement by developing a mechanical projector. The mechanical projector enables much broader spectral range of light than that the DLP projector allows. The rapidly spinning disk with binary structures can generate desired sinusoidal patterns at a frequency of 10 kHz or higher with a single DC motor. By precisely synchronizing the camera with the projector, phase-shifted fringe patterns can be accurately captured for high-accuracy 3D shape measurement. We further employed a computational framework that could enable absolute phase and thus absolute 3D shape measurement. We developed such prototype system that experimentally demonstrated the success of the proposed method.

  6. Tire-to-Surface Friction-Coefficient Measurements with a C-123B Airplane on Various Runway Surfaces

    Science.gov (United States)

    Sawyer, Richard H.; Kolnick, Joseph J.

    1959-01-01

    An investigation was conducted to obtain information on the tire-to-surface friction coefficients available in aircraft braking during the landing run. The tests were made with a C-123B airplane on both wet and dry concrete and bituminous pavements and on snow-covered and ice surfaces at speeds from 12 to 115 knots. Measurements were made of the maximum (incipient skidding) friction coefficient, the full-skidding (locked wheel) friction coefficient, and the wheel slip ratio during braking.

  7. Effect of surface fissure on apparent resistivity measurements

    Science.gov (United States)

    Sailhac, P.; Gance, J.; Malet, J.

    2013-12-01

    Fissures are features of interest, prone to create preferential flow path, modifying locally the soil hydrogeological behavior. Electrical Resistivity Tomography (ERT) is a suitable tool to monitor such preferential flow path. However, this technique is not efficient in the presence of surface fissure, due to a bad resistivity recovering around the fissure vicinity during the inversion process. Therefore, we propose a description of fissure effect on raw apparent resistivity on three resistivity arrays. The purposes of the study are multiple. First, we aim at making ERT users aware of surface fissure effect, and propose a first help to interpret basically resistivity pseudo sections. Second, we propose to ERT users to automatically conduct a surface fissure survey on the studied profile, in order to consider each fissure in a forward DC model and to suppress their effect. Finally, this study is only a first step toward 2D fissure shape inversion, and time-lapse monitoring of fissure drying and filling. In this study, we create a fissure model based on different geomorphological descriptors. After describing the FEM-DC forward modeling strategy, we investigate the fissure effect on pseudo section of apparent resistivity for a Wenner-Schlumberger (WS), a dipole-dipole (DD) and a gradient (GRAD) array. We determine a fissure detectability threshold for each array and perform a sensitivity analysis on the different fissure parameters (position, width, depth, dip angles...). The crack filling or drying effect is also investigated. The possibility to remove fissure effect and to propose a first interpretation of time-lapse data is illustrated on real data. This study show again the higher sensitivity of the DD array compared to the GRAD and WS arrays. Not only the maximal amplitude in the pseudo section is higher for the DD array, but also the anomaly pattern created by the fissure is much larger for this acquisition geometry. The minimal depth detectable for the DD

  8. Measurement of adhesion properties between topcoat paint and metallized/galvanized steel with surface energy measurement equipment.

    Science.gov (United States)

    2013-09-01

    The objectives of this research project are: (1) Compare the adhesion properties of NEPCOAT-approved topcoat paint over : metallized or galvanized steel. Use surface-energy measuring technique to characterize the wetting properties of the liqui...

  9. Seasonal Variability of Seawater Salinity and the Oxygen Isotopic Composition of Seawater in the Cariaco Basin, Venezuela

    Science.gov (United States)

    McConnell, M. C.; Thunell, R. C.; Tappa, E. J.; Wright, J. D.

    2005-12-01

    Monthly seawater oxygen isotope measurements (δ18Osw) were collected between May 1996- February 1997 and in May 2005 at various water depths in the Cariaco Basin, offshore Venezuela. The δ18Osw values are compared with concurrent salinity measurements to assess the δ18Osw:salinity relationship in this tropical region and to determine if there is significant seasonal variability in the relationship. The δ18Osw values range from 0.83‰ - 1.27‰ smow. The climatology of the region is driven by the seasonal migration of the ITCZ. During the winter and early spring, precipitation is low and upwelling is intense causing salinity to increase to ~37 psu. In contrast, during the Summer and early Fall when the ITCZ migrates to the north, upwelling ceases and precipitation increases causing surface salinities to decrease to ~36.2 psu. Preliminary results indicate that the strongest positive correlation between δ18Osw and salinity in the upper 400m occurred during May 2005 (R2= 0.93). However, the salinity:oxygen isotope relationship varies significantly over the course of the year. For example, the lightest δ18Osw values occurred during November 1996 possibly due to increased input of Orinoco River water into the Cariaco Basin. The relationships determined from our study will aid our understanding of paleosalinity variations in this region. Magnesium/calcium (Mg/Ca) ratios and the oxygen isotope composition (δ18Oc) were also measured in two surface dwelling planktonic foraminiferal species Globigerinoides ruber (white and pink variety) and Globigerina bulloides from bi-weekly sediment trap samples collected in the Cariaco Basin between 2003 and 2005. The Mg/Ca ratios range from 3.9-6.9 mmol/mol for G. ruber and 4.7-6.4mmol/mol for G. bulloides. The range in δ18Oc is 0.96‰ for G. ruber over ~5°C change in sea surface temperature (SST) and 0.50‰ for G. bulloides over ~2.5°C change in SST.

  10. Heat capacity mapping mission. [satellite for earth surface temperature measurement

    Science.gov (United States)

    Price, J. C.

    1978-01-01

    A Heat Capacity Mapping Mission (HCMM), part of a series of Applications Explorers Missions, is designed to provide data on surface heating as a response to solar energy input. The data is obtained by a two channel scanning radiometer, with one channel covering the visible and near-IR band between 0.5 and 1.1 micrometers, and the other covering the thermal-IR between 10.5 and 12.5 micrometers. The temperature range covered lies between 260 and 340 K, in 0.3 deg steps, with an accuracy at 280 K of plus or minus 0.5 K. Nominal altitude is 620 km, with a ground swath 700 km wide.

  11. Canonical measures on the moduli spaces of compact Riemann surfaces

    International Nuclear Information System (INIS)

    Nag, S.

    1988-08-01

    We first study some explicit relations between the canonical line bundle and the Hodge bundle over moduli spaces for low genus. This leads to a natural measure on the moduli space of every genus which is related to the Siegel symplectic metric on Siegel upper half-space as well as to the Hodge metric on the Hodge bundle. (author). 9 refs

  12. Direct measurement of surface-state conductance by microscopic four-point probe method

    DEFF Research Database (Denmark)

    Hasegawa, S.; Shiraki, I.; Tanikawa, T.

    2002-01-01

    For in situ measurements of local electrical conductivity of well defined crystal surfaces in ultrahigh vacuum, we have developed microscopic four-point probes with a probe spacing of several micrometres, installed in a scanning-electron - microscope/electron-diffraction chamber. The probe...... is precisely positioned on targeted areas of the sample surface by using piezoactuators. This apparatus enables conductivity measurement with extremely high surface sensitivity, resulting in direct access to surface-state conductivity of the surface superstructures, and clarifying the influence of atomic steps...

  13. Monitoring and modeling infiltration-recharge dynamics of managed aquifer recharge with desalinated seawater

    Science.gov (United States)

    Ganot, Yonatan; Holtzman, Ran; Weisbrod, Noam; Nitzan, Ido; Katz, Yoram; Kurtzman, Daniel

    2017-09-01

    We study the relation between surface infiltration and groundwater recharge during managed aquifer recharge (MAR) with desalinated seawater in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. We monitor infiltration dynamics at multiple scales (up to the scale of the entire pond) by measuring the ponding depth, sediment water content and groundwater levels, using pressure sensors, single-ring infiltrometers, soil sensors, and observation wells. During a month (January 2015) of continuous intensive MAR (2.45 × 106 m3 discharged to a 10.7 ha area), groundwater level has risen by 17 m attaining full connection with the pond, while average infiltration rates declined by almost 2 orders of magnitude (from ˜ 11 to ˜ 0.4 m d-1). This reduction can be explained solely by the lithology of the unsaturated zone that includes relatively low-permeability sediments. Clogging processes at the pond-surface - abundant in many MAR operations - are negated by the high-quality desalinated seawater (turbidity ˜ 0.2 NTU, total dissolved solids ˜ 120 mg L-1) or negligible compared to the low-permeability layers. Recharge during infiltration was estimated reasonably well by simple analytical models, whereas a numerical model was used for estimating groundwater recharge after the end of infiltration. It was found that a calibrated numerical model with a one-dimensional representative sediment profile is able to capture MAR dynamics, including temporal reduction of infiltration rates, drainage and groundwater recharge. Measured infiltration rates of an independent MAR event (January 2016) fitted well to those calculated by the calibrated numerical model, showing the model validity. The successful quantification methodologies of the temporal groundwater recharge are useful for MAR practitioners and can serve as an input for groundwater flow models.

  14. 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.

  15. Phosphorus in Hermatypic Coral Skeleton: Incorporation Mechanisms and a Potential Seawater Phosphate Proxy

    Science.gov (United States)

    Lavigne, M. G.; Sherrell, R. M.; Linsley, B. K.; Desenfant, F.

    2006-12-01

    Records of surface water nutrient availability with sub-seasonal resolution would provide crucial evidence in understanding the effects of annual to centennial scale climate variability on oceanic primary production. A direct coral proxy for seawater phosphate would complement low resolution records from established but quantitatively uncertain indirect proxies such as planktonic foraminiferal Cd/Ca. Very recently, Montagna et al. (2006) suggested that LA-ICP-MS measurements of P/Ca in deep sea corals could be used to reconstruct deep water phosphate, although the unknown phosphorus incorporation mechanism adds uncertainty to this emerging proxy.1 Our group is investigating the chemical form and incorporation mechanism for phosphorus in the hermatypic corals Montastrea faveolata (Martinique, Caribbean) and Porites lutea (Rarotonga, South Pacific) using laser ablation and solution phase ICP-MS techniques. We have well calibrated analyses of cleaned and uncleaned micro-drilled samples for a number of trace elements including P by solution phase HR-ICP-MS in Caribbean Montastrea coral. We have also analyzed the Rarotonga Porites coral by LA-ICP-MS resulting in high resolution (~ bi-weekly) phosphorus data over ~ 2.5 years. Phosphorus was resistant to rigorous solution cleaning of the drilled Martinique coral samples. This suggests incorporation largely in inorganic lattice-bound sites rather than as residual organic P or in association with Fe- Mn oxides. High skeletal P/Ca values are found just under the growing surface in the Martinique coral, decreasing exponentially within several millimeters, suggesting that organic P is remineralized quickly, leaving the residual ~constant signal. Both of these corals from the upper 20m had lower P/Ca than deep sea corals (100 - 1200 μmol/mol)1, and the mean P/Ca in Rarotonga Porites (~46 μmol/mol) is higher than in the Martinique Montastrea (18 μmol/mol). Both observations are consistent with the increase in PO4 with depth

  16. 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.

  17. Surface topography measurement by frequency sweeping digital holography.

    Czech Academy of Sciences Publication Activity Database

    Lédl, Vít; Psota, Pavel; Kaván, František; Matoušek, Ondřej; Mokrý, Pavel

    2017-01-01

    Roč. 56, č. 28 (2017), s. 7808-7814 ISSN 1559-128X R&D Projects: GA MŠk(CZ) LO1206; GA ČR(CZ) GA16-11965S Institutional support: RVO:61389021 Keywords : Wavelenght Scanning Interferometry * Shape measurement * Profilomerty Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Electrical and electronic engineering Impact factor: 1.650, year: 2016 https:// doi . org /10.1364/AO.56.007808

  18. Radioisotope tracer application in surface and groundwater flow measurements

    International Nuclear Information System (INIS)

    Monev, E.

    1983-01-01

    The ''peak to peak'' method for measurement of water flow with the use of radioactive tracer was investigated. The theoretical basis for this method has been established. The experiments in the open channel have shown the applicability of the method. Groundwater flow was studied by injection of radioactive tracer into the bore-hole followed by gamma-logging in three different time intervals. Interpretation of gamma lows in terms of filtration velocity in various depths proved to be possible

  19. Measurement system for special surface mapping using miniature displacement sensors

    Directory of Open Access Journals (Sweden)

    Zowade Martyna

    2018-01-01

    Full Text Available The aim of the work was to design a special system for measurements of elements with repetitive geometry or assemblies with repeating components, set in a linear patterns. The main focus was based on developing a computer program for signal analysis from variable number of miniature displacement sensors. It was set that the response for displacement of measuring tip from each sensor was a 0-5 V voltage signal with possibility of using different type of sensors. Requirements were determined based on projected measurement method. A special design of sensor was made for testing the computer program. If the characteristics of the sensor is known, it is possible to compute the type A evaluation of uncertainty. The results are presented in XY chart on computer screen. The program allows the user to choose any number of the sensors and determine the distance between them. Also, the possibility of calibration of sensors’ set was provided. The test were conducted on a prototype handle for sensors, made on a 3D printer.

  20. Radiolytic removal of trihalomethane in chlorinated seawater

    International Nuclear Information System (INIS)

    Rajamohan, R.; Rajesh, Puspalata; Venugopalan, V.P.; Rangarajan, S.; Natesan, Usha

    2015-01-01

    Biofouling is one of the major operational problems in seawater cooling systems. It is controlled by application of chlorine based biocides in the range of 0.5-2.0 mg L -1 . The bromide in seawater reacts with the added chlorine and forms hypobromous acid. The brominated residual biocides react with natural organic matter present in the seawater, resulting in the formation of trihalomethanes (THM) such as bromoform (CHBr 3 ), dibromochloromethane (CHBr 2 Cl) bromodichloromethane (CHBrCl 2 ). Though THMs represent a small fraction of the added chlorine, they are relatively more persistent than residual chlorine, and hence pose a potential hazard to marine life because of their reported mutagenicity. There have been few reports on removal of THMs from chlorinated seawater. In this work, the efficacy of gamma irradiation technique for the removal of THMs from chlorine-dosed seawater was investigated. Experiments were carried out using seawater collected from Kalpakkam. Irradiation study was conducted in chlorinated (1, 3, and 5 mg L -1 of Cl 2 ) seawater by applying various dosages (0.4-5.0 kGy) of gamma radiation using a 60 Co Gamma Chamber 5000. Bromoform showed a faster rate of degradation as compared to other halocarbons like bromodichloromethane and dibromochloromethane. This shows the change in total THM concentration with variation in the radiation dose and initial Cl 2 dosing. When the percentage degradation of all the three trihalomethane species was compared with applied doses, it was found that the maximum reduction occurred at a dose of 2.5 kGy. The reduction was almost similar for all the three doses (1, 3, 5 ppm of Cl 2 ) used for chlorination. With a further increase in radiation dose to 5.0 kGy, a slight increase in reduction was observed

  1. Tapered optical fiber sensor for chemical pollutants detection in seawater

    Science.gov (United States)

    Irigoyen, Maite; Sánchez-Martin, Jose Antonio; Bernabeu, Eusebio; Zamora, Alba

    2017-04-01

    Three tapered silica optical fibers, uncoated and coated with metallic (Al or Cu) and dielectric layers (TiO2), are employed to determine the presence of oil and Hazardous and Noxious Substances (HNS from now on) in water, by means of the measurement of their spectral transmittance. With our experimental assembly, the presence of oil and HNS spills can be detected employing the three different kinds of tapers, since the complete range of refractive indices of the pollutants (1.329-1.501) is covered with these tapers. The most suitable spectral range to detect the presence of a chemical pollutant in seawater has been identified and a complete spectral characterization of the three types of optical fiber tapers has been carried out. The results obtained show that, in general terms, these devices working together can be employed for the early detection of oil and HNS spills in seawater in a marine industrial environment. These sensors have many advantages, such as its low cost, its simplicity and versatility (with interesting properties as quick response and repeatability), and especially that they can be self-cleaned with seawater in motion.

  2. Influence of sampling points on inspection accuracy of free-form surfaces using coordinate measuring machine

    Science.gov (United States)

    Xie, Mengmin; Chen, Yueping; Zhang, Anshe; Fang, Rui

    2018-03-01

    The inspection accuracy of free-form surfaces is mainly affected by the processing, the number of sampling points, the distribution of sampling points, the measurement equipment and other factors. This paper focuses on the influence of sampling points on inspection accuracy of free-form surfaces, and isoparametric distribution was used in sample point distribution. Different sampling points number was compared on a same surface and a probe, the measurement data were analyzed and the optimal sampling points number was obtained.

  3. Corrosion-free solar collectors for thermally driven seawater desalination

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, M.; Koschikowski, J.; Rommel, M. [Fraunhofer Institute for Solar Energy Systems, Freiburg (Germany)

    2002-05-01

    Seawater desalination can be carried out by a variety of techniques, some of which are thermally driven at operating temperatures in the range of 70 to 120{sup o}C. At this temperature level, these systems can be supplied with thermal energy gained from solar flat-plate collectors. In order to increase the efficiency of such systems and simultaneously reduce costs, a heat exchanger between the collector loop and the desalination unit can be omitted if the seawater flows directly through the collector absorbers. Since hot seawater is very aggressive, this configuration requires corrosion-free absorbers. We developed collectors which fulfil this requirement. They were installed in a pilot plant in Pozo lzquierdo, Gran Canaria, which produces about 600 l of drinking water per day. The main task was to find materials which are resistant to seawater and can withstand stagnation temperatures up to 200{sup o}C, out of which appropriate absorber constructions had to be developed. Moreover, it had to be ensured that it was possible to apply a selective coating on the absorber. A further limitation was given by the aim for the resulting water costs. After investigating different materials and collector designs, we developed a prototype consisting of an array of selectively coated glass tubes mounted in a conventional flat-plate collector housing. The efficiency was increased by adding a specially shaped reflector. The design was developed by carrying out various optical and thermal simulations, and indoor as well as outdoor tests. We obtained appropriate collectors which fulfil the technical and economical requirements. Finally, first results of the in-situ measurements in Gran Canaria will be presented. (author)

  4. Optimal design of graphene nanopores for seawater desalination

    Science.gov (United States)

    Li, Zhongwu; Qiu, Yinghua; Li, Kun; Sha, Jingjie; Li, Tie; Chen, Yunfei

    2018-01-01

    Extensive molecular dynamics simulations are employed to optimize nanopore size and surface charge density in order to obtain high ionic selectivity and high water throughput for seawater desalination systems. It is demonstrated that with the help of surface charge exclusion, nanopores with diameter as large as 3.5 nm still have high ionic selectivity. The mechanism of the salt rejection in a surface-charged nanopore is mainly attributed to the ion concentration difference between the cations and anions induced by the surface charges. Increasing surface charge density is beneficial to enhance ionic selectivity. However, there exists a critical value for the surface charge density. Once the surface charge density exceeds the critical value, charge inversion occurs inside a nanopore. Further increasing the surface charge density will deteriorate the ionic selectivity because the highly charged nanopore surface will allow more coions to enter the nanopore in order to keep the whole system in charge neutrality. Besides the surface charge density, the nanopore length also affects the ionic selectivity. Based on our systematic simulations, nanopores with surface charge density between -0.09 C/m2 and -0.12 C/m2, diameters smaller than 3.5 nm, and membrane thickness ranging between 8 and 10 graphene layers show an excellent performance for the ionic selectivity.

  5. Effects of acidified seawater on coral calcification and variations of U/Ca ratio in their skeletons

    Science.gov (United States)

    Inoue, M.; Ozaki, S.; Iguchi, A.; Sakai, K.; Suzuki, A.; Kawahata, H.

    2011-12-01

    The rising CO2 concentration in the atmosphere is changing the carbonate chemistry of the ocean. Elevated partial pressure of CO2 (pCO2) has caused significant decrease in surface seawater pH and carbonate ion concentration. Therefore, ocean acidification has a negative effect on calcification of marine calcifying organisms. Especially, hermatypic corals are dominant organisms in coral reef ecosystems, so their calcificication is a key to determine the health of reef ecosystems. On the other hand, recent study has suggested that there is a negative correlation between U/Ca ratio in coral skeleton and seawater pH, based on the culture experiment using primary polyps of Acropora digitifera. In this study, primary polyps and adult colonies of A. digitifera and adult colonies of Porites australiensis, which are the dominant species around the Ryukyu Islands, Japan, were reared in seawater with different pCO2 (300, 400, 600, 800, 1000ppm) and pH (7.4, 7.6, 8.0) settings controlled by CO2 bubbling. Calcification rate of adult coral was estimated by buoyant method, while skeletal growth of polyps was evaluated by measuring the dry weight of each skeleton after the experiments. In order to evaluate the relationship between U/Ca ratios in coral skeletons and seawater pH, U/Ca ratios in reared corals were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results of A. digitifera showed that the growth rate of adult corals had no significant correlation against pCO2, but dry weight of polyp skeletons decreased with increase in pCO2. Growth rate of P. australiensis typically showed a positive correlation with pH. However, growth rates were different among colonies, suggesting that their responses to acidification may vary among the colonies. Regarding the variations of U/Ca ratios, there were positive correlations between U/Ca ratios in adults of A. digitifera and P. australiensis and seawater pCO2 (pH), while no relation was observed in polyp corals.

  6. Characterization of silicon surface states at clean and copper contaminated condition via transient capacitance measurement

    Science.gov (United States)

    Song, Lihui; Xie, Meng; Yu, Xuegong; Yang, Deren

    2017-10-01

    Silicon surface is one of the dominant recombination sites for silicon solar cells. Generally, the recombination ability of silicon surface is characterized in terms of surface recombination velocity. However, silicon surface actually contain a series of donor and acceptor levels across the silicon band gap, and therefore the surface recombination velocity is too general to provide detailed information of the silicon surface states. In this paper, we used the measured transient capacitance data to extract the detailed information (like defect energy levels, defect densities, and capture cross sections) of the silicon surface states. Furthermore, the influence of copper contamination on silicon surface states was examined, and it was found that copper contamination can change the localized energy levels of "clean" silicon surface states to the band-like energy levels, meanwhile the defect densities and capture cross sections were both enlarged.

  7. Preparation of Pt deposited nanotubular TiO2 as cathodes for enhanced photoelectrochemical hydrogen production using seawater electrolytes

    International Nuclear Information System (INIS)

    Nam, Wonsik; Oh, Seichang; Joo, Hyunku; Yoon, Jaekyung

    2011-01-01

    The purpose of this study was to develop effective cathodes to increase the production of hydrogen and use the seawater, an abundant resource in the earth as the electrolyte in photoelectrochemical systems. In order to fabricate the Pt/TiO 2 cathodes, various contents of the Pt precursor (0-0.4 wt%) deposited by the electrodeposition method were used. On the basis of the hydrogen evolution rate, 0.2 wt% Pt/TiO 2 was observed to exhibit the best performance among the various Pt/TiO 2 cathodes with the natural seawater and two concentrated seawater electrolytes obtained from single (nanofiltration) and combined membrane (nanofiltration and reverse osmosis) processes. The surface characterizations exhibited that crystal structures and morphological properties of Pt and TiO 2 found the results of XRD pattern and SEM/TEM images, respectively. - Graphical abstract: On the basis of photoelectrochemical hydrogen production, 0.2 wt% Pt/TiO 2 was observed to exhibit the best performance among the various Pt/TIO 2 cathodes with natural seawater. In comparison of hydrogen evolution rate with various seawater electrolytes, 0.2 wt% Pt/TiO 2 was found to show the better performance as cathode with the concentrated seawater electrolytes obtained from membrane. Highlights: → Pt deposited TiO 2 electrodes are used as cathode in PEC H 2 production. → Natural and concentrated seawater by membranes are used as electrolytes in PEC. → Pt/TiO 2 shows a good performance as cathode with seawater electrolytes. → H 2 evolution rate increases with more concentrated seawater electrolyte. → Highly saline seawater is useful resource for H 2 production.

  8. Surface Pressure Measurements of Atmospheric Tides Using Smartphones

    Science.gov (United States)

    Price, Colin; Maor, Ron

    2017-04-01

    Similar to the oceans, the atmosphere also has tides that are measured in variations of atmospheric pressure. However, unlike the gravitational tides in the oceans, the atmospheric tides are caused primarily in the troposphere and stratosphere when the atmosphere is periodically heated by the sun, due to tropospheric absorption by water vapor and stratospheric absorption by ozone. Due to the forcing being always on the day side of the globe, the tides migrate around the globe following the sun (migrating tides) with a dominant periodicity of 12 hours (and less so at 24 hours). In recent years smartphones have been equipped with sensitive, cheap and reliable pressure sensors that can easily detect these atmospheric tides. By 2020 it is expected that there will be more than 6 billion smartphones globally, each measuring continuously atmospheric pressure at 1Hz temporal resolution. In this presentation we will present some control experiments we have performed with smartphones to monitor atmospheric tides, while also using random pressure data from more than 50,000 daily users via the WeatherSignal application. We conclude that smartphones are a useful tool for studying atmospheric tides on local and global scales.

  9. Development of an Assessment Procedure for Seawater Intrusion Mitigation

    Science.gov (United States)

    Hsi Ting, F.; Yih Chi, T.

    2017-12-01

    The Pingtung Plain is one of the areas with extremely plentiful groundwater resources in Taiwan. Due to that the application of the water resource is restricted by significant variation of precipitation between wet and dry seasons, groundwater must be used as a recharge source to implement the insufficient surface water resource during dry seasons. In recent years, the coastal aquaculture rises, and the over withdrawn of groundwater by private well results in fast drop of groundwater level. Then it causes imbalance of groundwater supply and leads to serious seawater intrusion in the coastal areas. The purpose of this study is to develop an integrated numerical model of groundwater resources and seawater intrusion. Soil and Water Assessment Tool (SWAT), MODFLOW and MT3D models were applied to analyze the variation of the groundwater levels and salinity concentration to investigate the correlation of parameters, which are used to the model applications in order to disposal saltwater intrusion. The data of groundwater levels, pumping capacity and hydrogeological data to were collected to build an integrated numerical model. Firstly, we will collect the information of layered aquifer and the data of hydrological parameters to build the groundwater numerical model at Pingtung Plain, and identify the amount of the groundwater which flow into the sea. In order to deal with the future climate change conditions or extreme weather conditions, we will consider the recharge with groundwater model to improve the seawater intrusion problem. The integrated numerical model which describes that seawater intrusion to deep confined aquifers and shallow unsaturated aquifers. Secondly, we will use the above model to investigate the weights influenced by different factors to the amount area of seawater intrusion, and predict the salinity concentration distribution of evaluation at coastal area of Pingtung Plain. Finally, we will simulate groundwater recharge/ injection at the coastal

  10. Development of pre-concentration procedure for the determination of Hg isotope ratios in seawater samples

    International Nuclear Information System (INIS)

    Štrok, Marko; Hintelmann, Holger; Dimock, Brian

    2014-01-01

    Highlights: • The method for the quantitative pre-concentration of Hg from seawater was developed. • First report of Hg isotope ratios in seawater is presented. • A unique mass independent 200 Hg isotope fractionation was observed. • This fractionation has unique potential to distinguish anthropogenic and natural Hg. - Abstract: Hg concentrations in seawater are usually too low to allow direct (without pre-concentration and removal of salt matrix) measurement of its isotope ratios with multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). Therefore, a new method for the pre-concentration of Hg from large volumes of seawater was developed. The final method allows for relatively fast (about 2.5 L h −1 ) and quantitative pre-concentration of Hg from seawater samples with an average Hg recovery of 98 ± 6%. Using this newly developed method we determined Hg isotope ratios in seawater. Reference seawater samples were compared to samples potentially impacted by anthropogenic activity. The results show negative mass dependent fractionation relative to the NIST 3133 Hg standard with δ 202 Hg values in the range from −0.50‰ to −1.50‰. In addition, positive mass independent fractionation of 200 Hg was observed for samples from reference sites, while impacted sites did not show significant Δ 200 Hg values. Although the influence of the impacted sediments is limited to the seawater and particulate matter in very close proximity to the sediment, this observation may raise the possibility of using Δ 200 Hg to distinguish between samples from impacted and reference sites

  11. Stabilization of arsenic and lead by magnesium oxide (MgO) in different seawater concentrations.

    Science.gov (United States)

    Kameda, Kentaro; Hashimoto, Yohey; Ok, Yong Sik

    2018-02-01

    Ongoing sea level rise will have a major impact on mobility and migration of contaminants by changing a number of natural phenomena that alter geochemistry and hydrology of subsurface environment. In-situ immobilization techniques may be a promising remediation strategy for mitigating contaminant mobility induced by sea level rise. This study investigated the reaction mechanisms of magnesium oxide (MgO) with aqueous Pb and As under freshwater and seawater using XAFS spectroscopy. Initial concentrations of Pb and As in freshwater strongly controlled the characteristics of the reaction product of MgO. Our study revealed that i) the removal of aqueous Pb and As by MgO was increased by the elevation of seawater concentration, and ii) the removal of As was attributed primarily to (inner-sphere) surface adsorption on MgO, independent on seawater concentrations, and iii) the retention mechanism of Pb was dependent on seawater concentrations where formations of Pb oxides and adsorption on the MgO surface were predominant in solutions with low and high salinity, respectively. The release of As fixed with MgO significantly increased in seawater compared to freshwater, although the amount of As desorbed accounted for <0.2% of total As. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Mercury isotope fractionation during transfer from post-desulfurized seawater to air.

    Science.gov (United States)

    Huang, Shuyuan; Lin, Kunning; Yuan, Dongxing; Gao, Yaqin; Sun, Lumin

    2016-12-15

    Samples of dissolved gaseous mercury (DGM) in the post-desulfurized seawater discharged from a coal-fired power plant together with samples of gaseous elemental mercury (GEM) over the post-desulfurized seawater surface were collected and analyzed to study the mercury isotope fractionation during transfer from post-desulfurized seawater to air. Experimental results showed that when DGM in the seawater was converted to GEM in the air, the δ 202 Hg and Δ 199 Hg values were changed, ranging from -2.98 to -0.04‰ and from -0.31 to 0.64‰, respectively. Aeration played a key role in accelerating the transformation of DGM to GEM, and resulted in light mercury isotopes being more likely to be enriched in the GEM. The ratio Δ 199 Hg/Δ 201 Hg was 1.626 in all samples, suggesting that mercury mass independent fractionation occurred owing to the nuclear volume effect during the transformation. In addition, mass independent fractionation of mercury even isotopes was found in the GEM above the post-desulfurized seawater surface in the aeration pool. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Cultivation of oleaginous Rhodotorula mucilaginosa in airlift bioreactor by using seawater.

    Science.gov (United States)

    Yen, Hong-Wei; Liao, Yu-Ting; Liu, Yi Xian

    2016-02-01

    The enormous water resource consumption is a concern to the scale-up fermentation process, especially for those cheap fermentation commodities, such as microbial oils as the feedstock for biodiesel production. The direct cultivation of oleaginous Rhodotorula mucilaginosa in a 5-L airlift bioreactor using seawater instead of pure water led to a slightly lower biomass being achieved, at 17.2 compared to 18.1 g/L, respectively. Nevertheless, a higher lipid content of 65 ± 5% was measured in the batch using seawater as compared to the pure water batch. Both the salinity and osmotic pressure decreased as the cultivation time increased in the seawater batch, and these effects may contribute to the high tolerance for salinity. No effects were observed for the seawater on the fatty acid profiles. The major components for both batches using seawater and pure water were C16:0 (palmitic acid), C18:1 (oleic acid) and C18:2 (linoleic acid), which together accounted for over 85% of total lipids. The results of this study indicated that seawater could be a suitable option for scaling up the growth of oleaginous R. mucilaginosa, especially from the perspective of water resource utilization. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Application of vacuum-assisted closure in seawater-immersed wound treatment under different negative pressures.

    Science.gov (United States)

    Cao, L; Peng, M M; Sun, J J; Yu, X C; Shi, B

    2015-06-11

    The therapeutic effect of vacuum-assisted closure (VAC) has been confirmed in many types of complex wounds, but there are few relevant reports regarding seawater-immersed wounds. The aim of this study was to determine the effect of VAC on seawater-immersed wound healing under different negative pressures and explore the optimal negative pressure value. Four purebred miniature pigs were used as the experimental animal models. Four acute, symmetrical wounds were made on each side of the spine and designated as the experimental group (wounds with 2 h of seawater immersion) and the control group (wounds without seawater immersion). Wounds were divided into a conventional dressing group and 3 further groups with different VAC therapies (negative pressure at either 120, 180, or 240 mmHg). The extent of wound healing, and speed of granulation growth and re-epithelialization were measured. Bacterial flora distribution in the wounds was observed, and fibronectin levels in the exudate of the wounds were tested. Results showed that seawater immersion aggravated wound injury and that VAC therapy with 180 mmHg negative pressure induced the fastest epidermis migration, obvious edema elimination, significant capillary proliferation, and the highest level of fibronectin, and that in wounds, the proportion of Gram-negative bacteria tended to decrease and that of Gram-positive bacteria tended to increase. Our results show that VAC promotes seawater-immersed wound healing and that 180 mmHg negative pressure may be optimal for wound healing.

  15. Development of pre-concentration procedure for the determination of Hg isotope ratios in seawater samples.

    Science.gov (United States)

    Štrok, Marko; Hintelmann, Holger; Dimock, Brian

    2014-12-03

    Hg concentrations in seawater are usually too low to allow direct (without pre-concentration and removal of salt matrix) measurement of its isotope ratios with multicollector-inductively coupled plasma mass spectrometry (MC-ICP-MS). Therefore, a new method for the pre-concentration of Hg from large volumes of seawater was developed. The final method allows for relatively fast (about 2.5Lh(-1)) and quantitative pre-concentration of Hg from seawater samples with an average Hg recovery of 98±6%. Using this newly developed method we determined Hg isotope ratios in seawater. Reference seawater samples were compared to samples potentially impacted by anthropogenic activity. The results show negative mass dependent fractionation relative to the NIST 3133 Hg standard with δ(202)Hg values in the range from -0.50‰ to -1.50‰. In addition, positive mass independent fractionation of (200)Hg was observed for samples from reference sites, while impacted sites did not show significant Δ(200)Hg values. Although the influence of the impacted sediments is limited to the seawater and particulate matter in very close proximity to the sediment, this observation may raise the possibility of using Δ(200)Hg to distinguish between samples from impacted and reference sites. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. [The effect of hypertonic seawater and isotonic seawater for nasal mucosa of allergic rhinitis mice model].

    Science.gov (United States)

    Deng, Zhifeng; Xu, Yu; Ou, Jin; Xiang, Rong; Tao, Zezhang

    2014-12-01

    To study the effect of hypertonic seawater and isotonic seawater for nasal mucosa of allergic rhinitis mice model, and explore the possible mechanism of nasal irrigation with seawater in treatment of allergic rhinitis. We used Der pl to make allergic rhinitis model of BALB/c mice, and divided them into three groups randomly. Nasal irrigation with hypertonic seawater (HS) or isotonic seawater (IS) in the treatment group 1-14 days after modeling, and black control (BC) group was given no treatment after modeling. Normal control (NC) group was given no treatment, the number of rubs and sneezings in each group were counted in 30 min after the last nasal irrigation. Mice were then killed 24 h after the last therapy. The noses of mice from each group were removed and fixed, then the slices were stained with hematoxylin and eosin, the others were observed by transmission electron microscope. Mice with hypertonic seawater and isotonic seawater were significantly improved in rubs and sneezings compared to the black control group (P 0. 05); Ciliated columnar epithelium cells in mucosal tissues of HS group and IS group were arranged trimly, better than that in the black control group. Morphology and microstructure in nasal mucosal of HS group was closer to the normal group than in IS group. The injury of nasal mucosa ciliated epithelium was significantly improved by nasal irrigation with hypertonic seawater and isotonic seawater, and the former is better than the latter, the mechanism of nasal irrigation with seawater in treatment of allergic rhinitis may rely on repairing the injured nasal mucosa ciliated epithelium, thereby the symptoms of nasal was reduced.

  17. Automatic centroid detection and surface measurement with a digital Shack–Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    Yin, Xiaoming; Zhao, Liping; Li, Xiang; Fang, Zhongping

    2010-01-01

    With the breakthrough of manufacturing technologies, the measurement of surface profiles is becoming a big issue. A Shack–Hartmann wavefront sensor (SHWS) provides a promising technology for non-contact surface measurement with a number of advantages over interferometry. The SHWS splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. So the accuracy of the centroid measurement determines the accuracy of the SHWS. In this paper, we have presented a new centroid measurement algorithm based on an adaptive thresholding and dynamic windowing method by utilizing image-processing techniques. Based on this centroid detection method, we have developed a digital SHWS system which can automatically detect centroids of focal spots, reconstruct the wavefront and measure the 3D profile of the surface. The system has been tested with various simulated and real surfaces such as flat surfaces, spherical and aspherical surfaces as well as deformable surfaces. The experimental results demonstrate that the system has good accuracy, repeatability and immunity to optical misalignment. The system is also suitable for on-line applications of surface measurement

  18. Surfactant induced complex formation and their effects on the interfacial properties of seawater.

    Science.gov (United States)

    Guzmán, Eduardo; Santini, Eva; Benedetti, Alessandro; Ravera, Francesca; Ferrari, Michele; Liggieri, Libero

    2014-11-01

    The effect of a cationic surfactant, hexadecyltrimethylammonium bromide (CTAB), on the interfacial properties of seawater has been studied by dynamic and equilibrium surface tension and by dilational rheology essays. Important modifications of the surface tension and dilational rheology response have been observed already at the very low CTAB concentrations, where the effects due to the high ionic strength are negligible. The comparison with the effects of CTAB in different seawater models, or in natural seawater fractions, points out the establishment of strong interactions between the surfactant molecules and the lipophilic fraction of organic material dispersed/dissolved in seawater, affecting the interfacial activity of the molecules. Considering the biochemical richness of seawater, these results can be explained assuming interaction mechanisms and adsorption schemes similar to those speculated for protein and other macromolecules in the presence of surfactants, which in fact show similar features. Thus already at the low concentrations the surfactant molecules form highly surface-active complexes with part of the organic fraction of seawater. At the larger surfactant concentrations these complexes compete for adsorption with an excess of free CTAB molecules which, according to the thermodynamic conditions, are most favoured to occupy the liquid interface. The results of this study underline the important role of the sea organic content in enhancing the surface-activity of surfactants, which is relevant for a deeper understand of the direct and indirect effects of these types of pollutants on the physico-chemical environment in the sea coastal areas and develop mitigation strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Forces due to surface water measured by force microscopy. Consequences for anchoring biological cells to surfaces

    International Nuclear Information System (INIS)

    Schilcher, K.

    1997-05-01

    Interaction forces in 'Scanning Force Microscopy' (SFM). Force curves revealed exponentially decaying, attractive forces between silicon tip and silicon sample in aqueous media. Replacing the silicon sample by a sheet of mica, the interaction forces had both, an attractive and a repulsive component. Addition of salts generally reduced the forces. At 500 mM salt concentration, the attractive force became quantized with a residual force value of 23 pN. The attractive force is attributed to the gain in energy of water molecules which are released from surface water into free water during tip-sample approach. This conclusion is supported by a statistical model. The repulsive force contribution in the case of mica, is caused by hydration forces due to the spatial organization of crystalline water on the mica surface. Anchoring of biological cells. Molecular resolution of cell surfaces by SFM requires cell anchoring without interference with cell physiology. For this a novel strategy, 'hydrophobic anchoring' was designed. It avoids strong attractive forces between cell and by using a flexible spacer molecule. It establishes anchoring by a lipid (bound to the spacer), which weakly interacts with the hydrophobic core of the cell membrane. The method was subjected to tests using RBL-2H3, CH0 αβ and HEK-293 cells. The strength of cell anchoring was assayed by shear forces. In all cases 'hydrophobic anchoring' via a spacer caused elective anchoring much beyond controls. Such cell anchoring was employed for the imaging of RBL-2H3 cells by SFM. Images showed considerable finer details than images of loosely adsorbed cells. With about 50 rim resolution, SFM succeeded in imaging microvilli, filopodia, single cytoskeletal fibers (microtubules, microfilaments) and vesicles. In addition, as a consequence of cell stimulation upon ionomycin treatment, lamellae formation and the appearance of secretory granules on top of them were observed which indicates the viability of anchored

  20. The effect of scattered light sensor orientation on roughness measurement of curved polished surfaces

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

    with crossed surface lay to document the robustness of the method. The instrument area-integrating measuring principle (figure 1) is based on a non-coherent light beam of ∅ 0.9 mm and 670 nm wavelength illuminating the measured surface, reflection of the incident light from the surface slopes in spatial......The effect of angular orientation of a scattered light sensor with respect to main curvature and surface lay on roughness measurements is evaluated. A commercial scattered light sensor OS 500-32 from Optosurf GmbH was used. The investigation was performed on polished cylindrical surfaces...... directions, and its acquisition within ± 16º angular range with a linear detector array. From the distribution of the acquired scattered light intensity, a number of statistical parameters describing the surface texture are calculated, where the Aq parameter (variance of the scattered light distribution...

  1. Performance and flow characteristics of MHD seawater thruster

    Energy Technology Data Exchange (ETDEWEB)

    Doss, E.D.

    1990-01-01

    The main goal of the research is to investigate the effects of strong magnetic fields on the electrical and flow fields inside MHD thrusters. The results of this study is important in the assessment of the feasibility of MHD seawater propulsion for the Navy. To accomplish this goal a three-dimensional fluid flow computer model has been developed and applied to study the concept of MHD seawater propulsion. The effects of strong magnetic fields on the current and electric fields inside the MHD thruster and their interaction with the flow fields, particularly those in the boundary layers, have been investigated. The results of the three-dimensional computations indicate that the velocity profiles are flatter over the sidewalls of the thruster walls in comparison to the velocity profiles over the electrode walls. These nonuniformities in the flow fields give rise to nonuniform distribution of the skin friction along the walls of the thrusters, where higher values are predicted over the sidewalls relative to those over the electrode walls. Also, a parametric study has been performed using the three-dimensional MHD flow model to analyze the performance of continuous electrode seawater thrusters under different operating parameters. The effects of these parameters on the fluid flow characteristics, and on the thruster efficiency have been investigated. Those parameters include the magnetic field (10--20 T), thruster diameter, surface roughness, flow velocity, and the electric load factor. The results show also that the thruster performance improves with the strength of the magnetic field and thruster diameter, and the efficiency decreases with the flow velocity and surface roughness.

  2. Adaptive fringe-pattern projection for image saturation avoidance in 3D surface-shape measurement.

    Science.gov (United States)

    Li, Dong; Kofman, Jonathan

    2014-04-21

    In fringe-projection 3D surface-shape measurement, image saturation results in incorrect intensities in captured images of fringe patterns, leading to phase and measurement errors. An adaptive fringe-pattern projection (AFPP) method was developed to adapt the maximum input gray level in projected fringe patterns to the local reflectivity of an object surface being measured. The AFPP method demonstrated improved 3D measurement accuracy by avoiding image saturation in highly-reflective surface regions while maintaining high intensity modulation across the entire surface. The AFPP method can avoid image saturation and handle varying surface reflectivity, using only two prior rounds of fringe-pattern projection and image capture to generate the adapted fringe patterns.

  3. Experimental measurements of surface stiffness on water-saturated porous solids

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, P.B.; Blaho, G. (Department of Welding Engineering, The Ohio State University, Columbus, Ohio 43210 (United States))

    1994-02-01

    The surface impedance of a fluid/fluid-saturated porous solid interface is defined as the ratio of the pressure difference between the fluids on the two sides of the interface and the volume velocity of the fluid through the surface pores. In most cases, the surface pores are inherently open'' and the surface impedance is negligible when the sample is fully submerged in fluid. On the other hand, due to surface tension, practically closed-pore boundary conditions can prevail at an interface between a nonwetting fluid (e.g., air) and a porous solid saturated with a wetting fluid (e.g., water). This effect is caused by the high stiffness of the microscopic fluid membranes extended by capillary forces over the otherwise open surface pores. We have determined the quasistatic surface stiffness of different water-saturated porous materials by changing the hydrostatic pressure and directly measuring the average surface displacement by an acoustical sensor. Generally, the surface stiffness is proportional to the surface tension of the wetting fluid and inversely proportional to the static permeability of the specimen. For cylindrical pores, the measured surface stiffness is in good agreement with theoretical predictions. For more irregular geometries, such as consolidated spherical beads, the surface stiffness is still inversely proportional to the static permeability but its value is orders of magnitudes lower than for cylindrical pores of comparable permeability.

  4. Surface energy balance measurements in the Mexico City: a review

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda Martinez, A. [Universidad Veracruzana, Xalapa, Veracruz (Mexico); Jauregui Ostos, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, UNAM, Mexico, D.F. (Mexico)

    2005-01-01

    During the last decade of the 20th Century, diverse campaigns for measuring the atmospheric energy balance were performed in downtown Mexico City (School of Mines and Preparatory School No. 7), in the southern suburbs (University Reserve) and in the surrounding rural areas (Plan Texcoco), in addition to a campaign carried out in 1985 in the Tacubaya district, a suburban western peripheral site. The objective was to obtain data for a better understanding of the climatic alterations due to urbanization, particularly to describe the role that the modification of the natural ground cover has played as a result of paving and the construction of urban canyons. In this paper, a review of these campaigns is presented. Energy partitioning in some areas (Tacubaya and Preparatory School No.7) is similar to that observed in urban centers of middle latitudes, whereas the major contrast was observed between Texcoco, with maximum energy consumption through evaporation, and School of Mines, where the latent heat is as low as in a desert. From the values of the correlations among the different components of energy balance, it may be possible to attempt the modeling of the diverse components of energy balance by means of regression equations starting from the net radiation. Those same coefficients distinguish the type of environment: urban, suburban or rural. [Spanish] Las primeras mediciones de balance energetico en la Ciudad de Mexico se realizaron en 1985 en un suburbio al poniente de la ciudad (el observatorio de Tacubaya). Ya en la decada de los anos noventa del siglo XX, dichas observaciones se multiplicaron tanto en el centro historico (antigua Escuela de Minas y en el edificio de la Preparatoria No. 7), como en otros sitios al sur (en terrenos de Ciudad Universitaria) y en la periferia rural (Plan Texcoco). El proposito de estas mediciones ha sido tener un mejor entendimiento de las alteraciones climaticas debidas a la urbanizacion. En este trabajo se presenta una revision

  5. Seawater Chemistry and the Advent of Biocalcification

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, S. T. [U.S. Geological Survey, Menlo Park, CA; Lowenstein, T K. [State University of New York, Binghamton; Horita, Juske [ORNL

    2004-01-01

    Major ion compositions of primary fluid inclusions from terminal Proterozoic (ca. 544 Ma) and Early Cambrian (ca. 515 Ma) marine halites indicate that seawater Ca{sup 2+} concentrations increased approximately threefold during the Early Cambrian. The timing of this shift in seawater chemistry broadly coincides with the 'Cambrian explosion,' a brief drop in marine {sup 87}Sr/{sup 86}Sr values, and an increase in tectonic activity, suggesting a link between the advent of biocalcification, hydrothermal mid-ocean-ridge brine production, and the composition of seawater. The Early Cambrian surge in oceanic [Ca{sup 2+}] was likely the first such increase following the rise of metazoans and may have spurred evolutionary changes in marine biota.

  6. Extracting Minerals from Seawater: An Energy Analysis

    Directory of Open Access Journals (Sweden)

    Ugo Bardi

    2010-04-01

    Full Text Available The concept of recovering minerals from seawater has been proposed as a way of counteracting the gradual depletion of conventional mineral ores. Seawater contains large amounts of dissolved ions and the four most concentrated metal ones (Na, Mg, Ca, K are being commercially extracted today. However, all the other metal ions exist at much lower concentrations. This paper reports an estimate of the feasibility of the extraction of these metal ions on the basis of the energy needed. In most cases, the result is that extraction in amounts comparable to the present production from land mines would be impossible because of the very large amount of energy needed. This conclusion holds also for uranium as fuel for the present generation of nuclear fission plants. Nevertheless, in a few cases, mainly lithium, extraction from seawater could provide amounts of metals sufficient for closing the cycle of metal use in the economy, provided that an increased level of recycling can be attained.

  7. Non-destructive plasma frequency measurement for a semiconductor thin film using broadband surface plasmon polaritons

    Science.gov (United States)

    Yang, Tao; Ge, Jia-cheng; Li, Xing-ao; Stantchev, Rayko Ivanov; Zhu, Yong-yuan; Zhou, Yuan; Huang, Wei

    2018-03-01

    Measurement of the plasma frequency of a semiconductor film using broadband surface plasmon is demonstrated in this paper. We theoretically deduce a formula about the relation between plasma frequency and characteristic surface plasmon frequency. The characteristic surface plasmon frequency can be captured from the cut-off frequency of the transmission spectra of the broadband surface plasmon, which is used to measure the plasma frequency indirectly. The plasma frequencies of an intrinsic indium antimonide with and without optical illuminance are measured with a THz time-domain spectrometer at room temperature. The experimental measured plasma frequencies fit well with theoretical and simulation results. Compared with other methods, the proposed method has a special advantage on measuring the plasma frequency for a thin semiconductor film coated on other materials.

  8. The nuclear energy in the seawater desalination

    International Nuclear Information System (INIS)

    Moreno A, J.; Flores E, R.M.

    2004-01-01

    In general, the hydric resources of diverse regions of the world are insufficient for to satisfy the necessities of their inhabitants. Among the different technologies that are applied for the desalination of seawater are the distillation processes, the use of membranes and in particular recently in development the use of the nuclear energy (Nuclear Desalination; System to produce drinkable water starting from seawater in a complex integrated in that as much the nuclear reactor as the desalination system are in a common location, the facilities and pertinent services are shared, and the nuclear reactor produces the energy that is used for the desalination process). (Author)

  9. Surface roughness characterization of Al-doped zinc oxide thin films using rapid optical measurement

    Science.gov (United States)

    Kuo, Chil-Chyuan

    2011-07-01

    Transparent conductive oxide thin films have been widely investigated in photoelectric devices such as flat panel display (FPD) and solar cells. Al-doped zinc oxide (AZO) thin films have been widely employed in FPD. Measuring the surface roughness of AZO thin films is important before the manufacturing of photoelectric device using AZO thin films because surface roughness of AZO thin films will significantly affect the performance of photoelectric device. Traditional methods to measure surface roughness of AZO thin films are scanning electron microscopy and atomic force microscopy. The disadvantages of these approaches include long lead time and slow measurement speed. To solve this problem, an optical inspection system for rapid measurement of the surface roughness of AZO thin films is developed in this study. It is found that the incident angle of 60° is a good candidate to measure the surface roughness of AZO thin films. Based on the trend equation y=-3.6483 x+2.1409, the surface roughness of AZO thin films ( y) can be directly deduced from the peak power density ( x) using the optical inspection system developed. The maximum measurement-error rate of the optical inspection system developed is less than 8.7%.The saving in inspection time of the surface roughness of AZO thin films is up to 83%.

  10. High-resolution hot-film measurement of surface heat flux to an impinging jet

    Science.gov (United States)

    O'Donovan, T. S.; Persoons, T.; Murray, D. B.

    2011-10-01

    To investigate the complex coupling between surface heat transfer and local fluid velocity in convective heat transfer, advanced techniques are required to measure the surface heat flux at high spatial and temporal resolution. Several established flow velocity techniques such as laser Doppler anemometry, particle image velocimetry and hot wire anemometry can measure fluid velocities at high spatial resolution (µm) and have a high-frequency response (up to 100 kHz) characteristic. Equivalent advanced surface heat transfer measurement techniques, however, are not available; even the latest advances in high speed thermal imaging do not offer equivalent data capture rates. The current research presents a method of measuring point surface heat flux with a hot film that is flush mounted on a heated flat surface. The film works in conjunction with a constant temperature anemometer which has a bandwidth of 100 kHz. The bandwidth of this technique therefore is likely to be in excess of more established surface heat flux measurement techniques. Although the frequency response of the sensor is not reported here, it is expected to be significantly less than 100 kHz due to its physical size and capacitance. To demonstrate the efficacy of the technique, a cooling impinging air jet is directed at the heated surface, and the power required to maintain the hot-film temperature is related to the local heat flux to the fluid air flow. The technique is validated experimentally using a more established surface heat flux measurement technique. The thermal performance of the sensor is also investigated numerically. It has been shown that, with some limitations, the measurement technique accurately measures the surface heat transfer to an impinging air jet with improved spatial resolution for a wide range of experimental parameters.

  11. Optical microscope for three-dimensional surface displacement and shape measurements at the microscale.

    Science.gov (United States)

    Xia, Shuman; Pan, Zhipeng; Zhang, Jingwen

    2014-07-15

    We report a novel optical microscope for full-field, noncontact measurements of three-dimensional (3D) surface deformation and topography at the microscale. The microscope system is based on a seamless integration of the diffraction-assisted image correlation (DAIC) method with fluorescent microscopy. We experimentally demonstrate the microscope's capability for 3D measurements with submicrometer spatial resolution and subpixel measurement accuracy.

  12. Digital Moiré based transient interferometry and its application in optical surface measurement

    Science.gov (United States)

    Hao, Qun; Tan, Yifeng; Wang, Shaopu; Hu, Yao

    2017-10-01

    Digital Moiré based transient interferometry (DMTI) is an effective non-contact testing methods for optical surfaces. In DMTI system, only one frame of real interferogram is experimentally captured for the transient measurement of the surface under test (SUT). When combined with partial compensation interferometry (PCI), DMTI is especially appropriate for the measurement of aspheres with large apertures, large asphericity or different surface parameters. Residual wavefront is allowed in PCI, so the same partial compensator can be applied to the detection of multiple SUTs. Excessive residual wavefront aberration results in spectrum aliasing, and the dynamic range of DMTI is limited. In order to solve this problem, a method based on wavelet transform is proposed to extract phase from the fringe pattern with spectrum aliasing. Results of simulation demonstrate the validity of this method. The dynamic range of Digital Moiré technology is effectively expanded, which makes DMTI prospective in surface figure error measurement for intelligent fabrication of aspheric surfaces.

  13. Nitrogen fate in a subtropical mangrove swamp: Potential association with seawater-groundwater exchange.

    Science.gov (United States)

    Xiao, Kai; Wu, Jiapeng; Li, Hailong; Hong, Yiguo; Wilson, Alicia M; Jiao, Jiu Jimmy; Shananan, Meghan

    2018-04-18

    Coastal mangrove swamps play an important role in nutrient cycling at the land-ocean boundary. However, little is known about the role of periodic seawater-groundwater exchange in the nitrogen cycling processes. Seawater-groundwater exchange rates and inorganic nitrogen concentrations were investigated along a shore-perpendicular intertidal transect in Daya Bay, China. The intertidal transect comprises three hydrologic subzones (tidal creek, mangrove and bare mudflat zones), each with different physicochemical characteristics. Salinity and hydraulic head measurements taken along the transect were used to estimate the exchange rates between seawater and groundwater over a spring-neap tidal cycle. Results showed that the maximum seawater-groundwater exchange occurred within the tidal creek zone, which facilitated high-oxygen seawater infiltration and subsequent nitrification. In contrast, the lowest exchange rate found in the mangrove zone caused over-loading of organic matter and longer groundwater residence times. This created an anoxic environment conducive to nitrogen loss through the anammox and denitrification processes. Potential oxidation rates of ammonia and nitrite were measured by the rapid and high-throughput method and rates of denitrification and anammox were measured by the modified membrane inlet mass spectrometry (MIMS) with isotope pairing, respectively. In the whole transect, denitrification accounted for 90% of the total nitrogen loss, and anammox accounted for the remaining 10%. The average nitrogen removal rate was about 2.07g per day per cubic meter of mangrove sediments. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Boron Removal in Seawater Reverse Osmosis System

    KAUST Repository

    Rahmawati, Karina

    2011-07-01

    Reverse osmosis successfully proves to remove more than 99% of solute in seawater, providing fresh water supply with satisfied quality. Due to some operational constraints, however, some trace contaminants removal, such as boron, cannot be achieved in one pass system. The stringent criterion for boron from World Health Organization (WHO) and Saudi Arabia local standard (0.5 mg/l) is hardly fulfilled by single pass sea water reverse osmosis (SWRO) plants. Some design processes have been proposed to deal with boron removal, but they are not economically efficient due to high energy and chemical consumption. The objective of this study was to study boron removal by different reverse osmosis membranes in two pH conditions, with and without antiscalant addition. Thus, it was expected to observe the possibility of operating single pass system and necessity to operate two pass system using low energy membrane. Five membrane samples were obtained from two different manufacturers. Three types of feed water pH were used, pH 8, pH 10, and pH 10 with antiscalant addition. Experiment was conducted in parallel to compare membrane performance from two manufacturers. Filtration was run with fully recycle mode for three days. Sample of permeate and feed were taken every 12 hours, and analyzed for their boron and TDS concentration. Membrane samples were also tested for their surface charge. The results showed that boron rejection increases as the feed pH increases. This was caused by dissociation of boric acid to negatively charged borate ion and more negatively charged membrane surface at elevated pH which enhance boron rejection. This study found that single pass reverse osmosis system, with and without elevating the pH, may not be possible to be applied because of two reasons. First, permeate quality in term of boron, does not fulfill WHO and local Saudi Arabia regulations. Second, severe scaling occurs due to operation in alkaline condition, since Ca and Mg concentration are

  15. Mid-Holocene sea surface conditions and riverine influence on the inshore Great Barrier Reef

    NARCIS (Netherlands)

    Roche, R.C.; Perry, C.T.; Smithers, S.G.; Leng, M.J.; Grove, C.A.; Sloane, H.J.; Unsworth, C.E.

    2014-01-01

    We present measurements of Sr/Ca, d18O, and spectral luminescence ratios (G/B) from a mid-Holocene Porites sp. microatoll recovered from the nearshore Great Barrier Reef (GBR). These records were used as proxies to reconstruct sea surface temperature (SST), the d18O of surrounding seawater (d18Osw),

  16. Visualization of the distribution of surface-active block copolymers in PDMS-based coatings

    DEFF Research Database (Denmark)

    Noguer, A. Camós; Latipov, R.; Madsen, F. B.

    2018-01-01

    and added to a PDMS coating for visualization purposes. The surface-activity and biofouling resistance of the synthesized copolymer was confirmed by water contact angle measurements and seawater immersion experiments. Confocal laser scanning microscopy (CLSM) images showed that the triblock copolymer...

  17. Locating karst depressed columns by means of Rn measurement on the surface

    International Nuclear Information System (INIS)

    Tang Daimao; Liu Hongfu; Duan Hongjie; Duan Lindi; Sui Haichen

    1999-01-01

    The coal mining and the related surface projects are extremely harassed by the underground karst depressed columns. The author discussed the surface Rn concentration's abnormality caused by the karst depressed columns. It is concluded that different kinds of karst depressed column can cause different Rn concentration's abnormality. The α-cup Rn measuring instrument was used for detecting Rn abnormality on the surface in order to locate the underground karst depressed columns

  18. Measurement of Fine Grain Copper Surface Texture Created by Abrasive Water Jet Cutting

    OpenAIRE

    HLAVÁČEK, Petr; VALÍČEK, Jan; HLOCH, Sergej; GREGER, Miroslav; FOLDYNA, Josef; IVANDIĆ, Željko; SITEK, Libor; KUŠNEROVÁ, Milena; ZELEŃÁK, Michal

    2009-01-01

    The paper presents results of experiments performed on copper with commercial purity to determine the influence of material grain size on both mechanical properties and texture of surface machined by abrasive water jet. An Equal Channel Angular Extrusion technology was used for creation of fine-grain copper samples. Hardness and grain size of fine-grain copper were measured, and, subsequently, surface of prepared copper samples was machined by abrasive water jet technology. Surface irregul...

  19. Three-dimensional measuring technique for surface topography using a light-sectioning microscope.

    Science.gov (United States)

    Xia, Linglin; Chen, Peifeng; Wang, Ying; Zhou, Le; Luo, Xi

    2012-03-10

    Three-dimensional (3D) surface topographic analysis, measurement, and assessment techniques have raised great interest not only among researchers but also among industrial users. Many industrial processes and applications are directly influenced by the small-scale roughness of surface finishes. This paper describes the development and implementation of a noncontact, three-dimensional, microtopography measuring system. The instrument is formed by combining a modified light-sectioning microscope subsystem with a computer subsystem. In particular, optical system characteristics of the light-sectioning microscope are investigated, and a textured steel sheet is measured to demonstrate good practical outcomes. Details of measuring processes and image processing algorithms are provided, such as procedures for measurement, image edge extraction, and 3D topography reconstruction. After the 3D topography of the measured surface has been reconstructed, the topography field description parameters are calculated. A standard roughness block was used for calibration of the surface microtopography measuring system. Results obtained showed the measurement method output has good agreement with the actual asperity (unevenness or roughness) of the surface. The computer subsystem is used to process and control asperity measurements and image generation, and for image acquisition and presentation.

  20. Biologically mediated dissolution of volcanic glass in seawater

    NARCIS (Netherlands)

    Staudigel, H.; Chastain, R.A.; Yayanos, A.; Davies, G.R.; Verdurmen, E.; Schiffman, P.; Bourcier, R.; de Baar, H.

    1998-01-01

    We studied the effects of biological mediation on the dissolution of basaltic glass in seawater. Experiments with typical seawater microbial populations were contrasted with a sterile control, and reactions were monitored chemically and isotopically. Biologically mediated experiments produce twice

  1. Aragonite coating solutions (ACS) based on artificial seawater

    Energy Technology Data Exchange (ETDEWEB)

    Tas, A. Cuneyt, E-mail: c_tas@hotmail.com

    2015-03-01

    Graphical abstract: - Highlights: • Developed completely inorganic solutions for the deposition of monolayers of aragonite spherules (or ooids). • Solutions mimicked the artificial seawater. • Biomimetic crystallization was performed at the tropical sea surface temperature of 30 °C. - Abstract: Aragonite (CaCO{sub 3}, calcium carbonate) is an abundant biomaterial of marine life. It is the dominant inorganic phase of coral reefs, mollusc bivalve shells and the stalactites or stalagmites of geological sediments. Inorganic and initially precipitate-free aragonite coating solutions (ACS) of pH 7.4 were developed in this study to deposit monolayers of aragonite spherules or ooids on biomaterial (e.g., UHMWPE, ultrahigh molecular weight polyethylene) surfaces soaked in ACS at 30 °C. The ACS solutions of this study have been developed for the surface engineering of synthetic biomaterials. The abiotic ACS solutions, enriched with calcium and bicarbonate ions at different concentrations, essentially mimicked the artificial seawater composition and started to deposit aragonite after a long (4 h) incubation period at the tropical sea surface temperature of 30 °C. While numerous techniques for the solution deposition of calcium hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}), of low thermodynamic solubility, on synthetic biomaterials have been demonstrated, procedures related to the solution-based surface deposition of high solubility aragonite remained uncommon. Monolayers of aragonite ooids deposited at 30 °C on UHMWPE substrates soaked in organic-free ACS solutions were found to possess nano-structures similar to the mortar-and-brick-type botryoids observed in biogenic marine shells. Samples were characterized using SEM, XRD, FTIR, ICP-AES and contact angle goniometry.

  2. Aragonite coating solutions (ACS) based on artificial seawater

    International Nuclear Information System (INIS)

    Tas, A. Cuneyt

    2015-01-01

    Graphical abstract: - Highlights: • Developed completely inorganic solutions for the deposition of monolayers of aragonite spherules (or ooids). • Solutions mimicked the artificial seawater. • Biomimetic crystallization was performed at the tropical sea surface temperature of 30 °C. - Abstract: Aragonite (CaCO 3 , calcium carbonate) is an abundant biomaterial of marine life. It is the dominant inorganic phase of coral reefs, mollusc bivalve shells and the stalactites or stalagmites of geological sediments. Inorganic and initially precipitate-free aragonite coating solutions (ACS) of pH 7.4 were developed in this study to deposit monolayers of aragonite spherules or ooids on biomaterial (e.g., UHMWPE, ultrahigh molecular weight polyethylene) surfaces soaked in ACS at 30 °C. The ACS solutions of this study have been developed for the surface engineering of synthetic biomaterials. The abiotic ACS solutions, enriched with calcium and bicarbonate ions at different concentrations, essentially mimicked the artificial seawater composition and started to deposit aragonite after a long (4 h) incubation period at the tropical sea surface temperature of 30 °C. While numerous techniques for the solution deposition of calcium hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 ), of low thermodynamic solubility, on synthetic biomaterials have been demonstrated, procedures related to the solution-based surface deposition of high solubility aragonite remained uncommon. Monolayers of aragonite ooids deposited at 30 °C on UHMWPE substrates soaked in organic-free ACS solutions were found to possess nano-structures similar to the mortar-and-brick-type botryoids observed in biogenic marine shells. Samples were characterized using SEM, XRD, FTIR, ICP-AES and contact angle goniometry

  3. Ag coated microneedle based surface enhanced Raman scattering probe for intradermal measurements

    Science.gov (United States)

    Yuen, Clement; Liu, Quan

    2013-06-01

    We propose a silver coated microneedle to detect test molecules, including R6G and glucose, positioned at a depth of more than 700 μm below a skin phantom surface for mimicking intradermal surface-enhanced Raman scattering measurements.

  4. Measuring and modeling the effect of surface moisture on the spectral reflectance of coastal beach sand

    NARCIS (Netherlands)

    Nolet, Corjan; Poortinga, Ate; Roosjen, Peter; Bartholomeus, Harm; Ruessink, Gerben|info:eu-repo/dai/nl/169093360

    2014-01-01

    Surface moisture is an important supply limiting factor for aeolian sand transport, which is the primary driver of coastal dune development. As such, it is critical to account for the control of surface moisture on available sand for dune building. Optical remote sensing has the potential to measure

  5. Effective aerodynamic roughness estimated from airborne laser altimeter measurements of surface features

    NARCIS (Netherlands)

    De Vries, AC; Kustas, WP; Ritchie, JC; Klaassen, W; Menenti, M; Rango, A; Prueger, JH

    2003-01-01

    Aerodynamic roughness length (z(0)) and displacement height (d(0)) are important surface parameters for estimating surface fluxes in numerical models. These parameters are generally determined from wind flow characteristics using logarithmic wind profiles measured at a meteorological tower or by

  6. On the measurement of the surface energy budget over a land ...

    Indian Academy of Sciences (India)

    e-mail: bhat@caos.iisc.ernet.in. The measurement of surface energy balance over a land surface in an open area in Bangalore is .... Sensors used in the present experimental setup and their specifications. These instruments were procured .... the value of the scalar at the roughness height zos. ψm and ψs are the M–O ...

  7. Calibration of a distributed hydrology and land surface model using energy flux measurements

    DEFF Research Database (Denmark)

    Larsen, Morten Andreas Dahl; Refsgaard, Jens Christian; Jensen, Karsten H.

    2016-01-01

    In this study we develop and test a calibration approach on a spatially distributed groundwater-surface water catchment model (MIKE SHE) coupled to a land surface model component with particular focus on the water and energy fluxes. The model is calibrated against time series of eddy flux measure...

  8. Clumped-isotope geochemistry of carbonates: A new tool for the reconstruction of temperature and oxygen isotope composition of seawater

    Energy Technology Data Exchange (ETDEWEB)

    Bernasconi, Stefano M., E-mail: Stefano.bernasconi@erdw.ethz.ch [Geological Institute, ETH Zuerich, Sonneggstrasse 5, 8092 Zuerich (Switzerland); Schmid, Thomas W.; Grauel, Anna-Lena [Geological Institute, ETH Zuerich, Sonneggstrasse 5, 8092 Zuerich (Switzerland); Mutterlose, Joerg [Institut fuer Geologie, Mineralogie und Geophysik, Ruhr Universitaet Bochum, Universitaetsstr. 150, 44801 Bochum (Germany)

    2011-06-15

    Highlights: > Clumped-isotope thermometry of carbonates is discussed. > Clumped isotopes of Belemnites show higher sea surface temperatures than commonly assumed for the lower Cretaceous. > The potential of clumped-isotope measurement on foraminifera is discussed. - Abstract: Clumped-isotope geochemistry deals with State of ordering of rare isotopes in molecules, in particular with their tendency to form bonds with other rare isotopes rather than with the most abundant ones. Among its possible applications, carbonate clumped-isotope thermometry is the one that has gained most attention because of the wide potential of applications in many disciplines of the earth sciences. In particular, it allows reconstructing the temperature of formation of carbonate minerals without knowledge of the isotopic composition of the water from which they were formed. In addition, the O isotope composition of the waters from which they were formed can be calculated using the {delta}{sup 18}O of the same carbonate sample. This feature offers new approaches in paleoclimatology for reconstructing past global geochemical cycles. In this contribution two applications of this method are presented. First the potential of a new analytical method of measurement of clumped isotopes on small samples of foraminifera, for high-resolution SST and seawater {delta}{sup 18}O reconstructions from marine sediments is shown. Furthermore the potential of clumped isotope analysis of belemnites, for reconstructing seawater {delta}{sup 18}O and temperatures in the Cretaceous is shown.

  9. Concentration of 99Tc in seawater by coprecipitation with iron hydroxide

    International Nuclear Information System (INIS)

    Momoshima, Noriyuki; Eto, Ichiro; Muhammad Sayad; Takashima, Yoshimasa

    1991-01-01

    A method for accumulation of 99 Tc in seawater has been developed. Technetium tracer in +VII oxidation state was added to the seawater together with reducing agent, potassium pyrosulfite, and coprecipitation agent, ferric chloride. After reduction of Tc(VII) at pH 4, Tc(IV) was coprecipitated as iron hydroxide by addition of sodium hydroxide to pH 9. The reduction and coprecipitation was quantitative and overall recovery of Tc was more than 98%. The green color of iron precipitate formed at pH 9 suggested that Tc(VII) as well as ferric ion was reduced under this condition. Adsorption of Tc(IV), however, was poor for iron hydroxide which was prepared in advance indicating active surface of freshly precipitated iron hydroxide is necessary for quantitative recovery of Tc(IV). A repeating coprecipitation technique was examined for enrichment of Tc in seawater that the same iron was used repeatedly as coprecipitater. After separation of iron hydroxide with Tc(IV) from supernatant, the precipitate was dissolved by addition of acid and then new seawater which contained reducing agent and Tc(VII) was added. Reduction and coprecipitation was again carried out. Good recovery was attained for 7 repeats. The proposed repeating coprecipitation technique was applicable to a large amount of seawater without increasing the amount of iron hydroxide which is subjected to radiochemical analysis. (author)

  10. Optimal scheduling of biocide dosing for seawater-cooled power and desalination plants

    KAUST Repository

    Mahfouz, Abdullah Bin

    2011-02-13

    Thermal desalination systems are typically integrated with power plants to exploit the excess heat resulting from the power-generation units. Using seawater in cooling the power plant and the desalination system is a common practice in many parts of the world where there is a shortage of freshwater. Biofouling is one of the major problems associated with the usage of seawater in cooling systems. Because of the dynamic variation in the power and water demands as well as the changes in the characteristics of seawater and the process, there is a need to develop an optimal policy for scheduling biocide usage and cleaning maintenance of the heat exchangers. The objective of this article is to introduce a systematic procedure for the optimization of scheduling the dosing of biocide and dechlorination chemicals as well as cleaning maintenance for a power production/thermal desalination plant. A multi-period optimization formulation is developed and solved to determine: the optimal levels of dosing and dechlorination chemicals; the timing of maintenance to clean the heat-exchange surfaces; and the dynamic dependence of the biofilm growth on the applied doses, the seawater-biocide chemistry, the process conditions, and seawater characteristics for each time period. The technical, economic, and environmental considerations of the system are accounted for. A case study is solved to elucidate the applicability of the developed optimization approach. © 2011 Springer-Verlag.

  11. Development of a laser-based sensor to measure true road surface deflection.

    Science.gov (United States)

    2017-04-01

    The high-speed measurement of accurate pavement surface deflections under a moving wheel at a networklevel : still remains a challenge in pavement engineering. This goal cannot be accomplished with stationary deflectionmeasuring : devices. Engineers ...

  12. Comparison of two methods of surface profile extraction from multiple ultrasonic range measurements

    NARCIS (Netherlands)

    Barshan, B; Baskent, D

    Two novel methods for surface profile extraction based on multiple ultrasonic range measurements are described and compared. One of the methods employs morphological processing techniques, whereas the other employs a spatial voting scheme followed by simple thresholding. Morphological processing

  13. Surface-Borne Time-of-Reception Measurements (STORM), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Invocon proposes the Surface-borne Time-Of-Reception Measurements (STORM) system as a method to locate the position of lightning strikes on aerospace vehicles....

  14. Durability of metakaolin geopolymers with various sodium silicate/sodium hydroxide ratios against seawater exposure

    Science.gov (United States)

    Jaya, Nur Ain; Abdullah, Mohd Mustafa Al Bakri; Li, Long-Yuan; Sandu, Andrei Victor; Hussin, Kamarudin; Ming, Liew Yun

    2017-09-01

    This work presents an investigation of the performance of metakaolin geopolymers exposed to the continuous immersion of seawater. The geopolymers were prepared from metakaolin by activating with a mixture of sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solutions and cured at 80°C. The ratios of sodium silicate to sodium hydroxide were varied from 0.20 to 0.32. The result showed that metakaolin geopolymers reduce in strength after immersion in seawater for 28 days. The unexposed samples with highest compressive strength attained greatest strength retention. White deposits were formed on the surface of the geopolymers after the exposure to seawater which was believed due to the depolymerisation process of the geopolymer network. Even so, the metakaolin geopolymers did not substantially change in dimension and remain structurally intact.

  15. Mitigation of biofouling using electromagnetic fields in tubular heat exchangers-condensers cooled by seawater.

    Science.gov (United States)

    Trueba, Alfredo; García, Sergio; Otero, Félix M

    2014-01-01

    Electromagnetic field (EMF) treatment is presented as an alternative physical treatment for the mitigation of biofouling adhered to the tubes of a heat exchanger-condenser cooled by seawater. During an experimental phase, a fouling biofilm was allowed to grow until experimental variables indicated that its growth had stabilised. Subsequently, EMF treatment was applied to seawater to eliminate the biofilm and to maintain the achieved cleanliness. The results showed that EMFs precipitated ions dissolved in the seawater. As a consequence of the application of EMFs, erosion altered the intermolecular bonding of extracellular polymers, causing the destruction of the biofilm matrix and its detachment from the inner surface of the heat exchanger-condenser tubes. This detachment led to the partial removal of a mature biofilm and a partial recovery of the efficiency lost in the heat transfer process by using a physical treatment that is harmless to the marine environment.

  16. Measuring grinding surface roughness based on the sharpness evaluation of colour images

    International Nuclear Information System (INIS)

    Huaian, Y I; Jian, L I U; Enhui, L U; Peng, A O

    2016-01-01

    Current machine vision-based detection methods for metal surface roughness mainly use the grey values of images for statistical analysis but do not make full use of the colour information and ignore the subjective judgment of the human vision system. To address these problems, this paper proposes a method to measure surface roughness through the sharpness evaluation of colour images. Based on the difference in sharpness of virtual images of colour blocks that are formed on grinding surfaces with different roughness, an algorithm for evaluating the sharpness of colour images that is based on the difference of the RGB colour space was used to develop a correlation model between the sharpness and the surface roughness. The correlation model was analysed under two conditions: constant illumination and varying illumination. The effect of the surface textures of the grinding samples on the image sharpness was also considered, demonstrating the feasibility of the detection method. The results show that the sharpness is strongly correlated with the surface roughness; when the illumination and the surface texture have the same orientation, the sharpness clearly decreases with increasing surface roughness. Under varying illumination, this correlation between the sharpness and surface roughness was highly robust, and the sharpness of each virtual image increased linearly with the illumination. Relative to the detection method for surface roughness using gray level co-occurrence matrix or artificial neural network, the proposed method is convenient, highly accurate and has a wide measurement range. (paper)

  17. Measurement uncertainty and gauge capability of surface roughness measurements in the automotive industry: a case study

    International Nuclear Information System (INIS)

    Drégelyi-Kiss, Ágota; Czifra, Árpád

    2014-01-01

    The calculation methods of the capability of measurement processes in the automotive industry differ from each other. There are three main calculation methods: MSA, VDA 5 and the international standard, ISO 22514–7. During this research our aim was to compare the capability calculation methods in a case study. Two types of automotive parts (ten pieces of each) are chosen to examine the behaviour of the manufacturing process and to measure the required characteristics of the measurement process being evaluated. The measurement uncertainty of the measuring process is calculated according to the VDA 5 and ISO 22514–7, and MSA guidelines. In this study the conformance of a measurement process in an automotive manufacturing process is determined, and the similarities and the differences between the methods used are shown. (paper)

  18. Seawater-softening process through formation of calcite ooids

    Directory of Open Access Journals (Sweden)

    A.A. Bakr

    2015-03-01

    Full Text Available Conventional water-softening processes usually involve the exchange of Na+ ions for Ca2+ and Mg2+ using commercial or synthesized ion exchangers. The differences in chemical compositions of the ooids can be attributed to the formation in different environments. In this paper, ooid grains form inside assembled semi-pilot softening unit through a continuous chemical process involving reaction between bicarbonate ions and added lime using natural seawater. Our sample of Mediterranean seawater has low Mg2+/Ca2+ ratio (1.98% within the range chemically favorable for precipitation of low-Mg calcite ooids. Precipitation of calcite occurs around pure quartz sand grains which act as nucleation points (the bed required for sand vessel is 1.65 l. The shape of the sand grains controls the overall external morphology of the resulting ooids; they vary in size from 0.5 to 3.0 mm and have a high degree of polish due to surface abrasion caused by continuous agitation inside the softening system. Calcite ooid grains (1.53 kg formed within the seawater-softening unit every 18 days have many of the ooid features formed in marine environments. Ooids grow to a significant size, at a rate of about 0.17 mm of one layer thickness per day inside the softening unit. The average weight percent of calcite precipitate is 35.48% after 18 days, at 10 °C, 60 l/min and pH 9.0. The pellets comprise mainly CaCO3 and SiO2 and some metal ions which may substitute for calcium ions in calcite are present only in trace amounts of the total composition.

  19. Progress in the specification of optical instruments for the measurement of surface form and texture

    Science.gov (United States)

    de Groot, Peter J.

    2014-05-01

    Specifications for confocal microscopes, optical interferometers and other methods of measuring areal surface topography can be confusing and misleading. The emerging ISO 25178 standards, together with the established international vocabulary of metrology, provide a foundation for improved specifications for 3D surface metrology instrumentation. The approach in this paper links instrument specifications to metrological characteristics that can influence a measurement, using consistent definitions of terms, and reference to verification procedures.

  20. Stability of phosphorus species in seawater

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; Somasundar, K.; Rajendran, A.

    couples in acidic and basic solutions, respectively, in anoxic conditions. H sub(3) PO sub(4)/H sub(4) P sub(2) O sub(6) and H sub(3) PO sub(2)/P super(0) are the important reducing couples in seawater. HPO and H PO are the stable ones in oxic and anoxic...