A potential explanation for the effect of carbon source on the ...

African Journals Online (AJOL)

USER

2010-08-16

Aug 16, 2010 ... structure, mixed liquor suspended solids (MLSS), sludge volume index (SVI) .... Fine air bubbles for aeration were supplied through an air sparger at the ..... Ren TT, Liu L, Sheng GP, Liu XW, Yu HQ, Zhang MC, Zhu JR (2008).

Application of Acoustic and Optic Methods for Estimating Suspended-Solids Concentrations in the St. Lucie River Estuary, Florida

Science.gov (United States)

Patino, Eduardo; Byrne, Michael J.

2004-01-01

Acoustic and optic methods were applied to estimate suspended-solids concentrations in the St. Lucie River Estuary, southeastern Florida. Acoustic Doppler velocity meters were installed at the North Fork, Speedy Point, and Steele Point sites within the estuary. These sites provide varying flow, salinity, water-quality, and channel cross-sectional characteristics. The monitoring site at Steele Point was not used in the analyses because repeated instrument relocations (due to bridge construction) prevented a sufficient number of samples from being collected at the various locations. Acoustic and optic instruments were installed to collect water velocity, acoustic backscatter strength (ABS), and turbidity data that were used to assess the feasibility of estimating suspended-solids concentrations in the estuary. Other data collected at the monitoring sites include tidal stage, salinity, temperature, and periodic discharge measurements. Regression analyses were used to determine the relations of suspended-solids concentration to ABS and suspended-solids concentration to turbidity at the North Fork and Speedy Point sites. For samples used in regression analyses, measured suspended-solids concentrations at the North Fork and Speedy Point sites ranged from 3 to 37 milligrams per liter, and organic content ranged from 50 to 83 percent. Corresponding salinity for these samples ranged from 0.12 to 22.7 parts per thousand, and corresponding temperature ranged from 19.4 to 31.8 ?C. Relations determined using this technique are site specific and only describe suspended-solids concentrations at locations where data were collected. The suspended-solids concentration to ABS relation resulted in correlation coefficients of 0.78 and 0.63 at the North Fork and Speedy Point sites, respectively. The suspended-solids concentration to turbidity relation resulted in correlation coefficients of 0.73 and 0.89 at the North Fork and Speedy Point sites, respectively. The adequacy of the

Geochemistry of suspended and settling solids in two freshwater lakes.

NARCIS (Netherlands)

Koelmans, A.A.

1998-01-01

This study describes the 1987–1992 time variationof the bulk chemical composition, levels of heavymetals, arsenic, nitrogen and phosporous insuspended and settling solids in Lake Volkerak andLake Zoom (The Netherlands). Suspended and setlingsolids were collected with continuous flowcentrifuges and

Comparison of Suspended Solid Separation in Advanced Storm Overflow Structures

DEFF Research Database (Denmark)

Larsen, Torben; Sørensen, Morten Steen

1990-01-01

This paper describes a laboratory investigation of the separation of suspended solids in a circular weir overflow and a vortex separator. The basic idea is to evaluate the efficiency of a vortical flow in the overflow chamber, and to compare these results with other overflow structures....

Artificial neural network modelling of a large-scale wastewater treatment plant operation.

Science.gov (United States)

Güçlü, Dünyamin; Dursun, Sükrü

2010-11-01

Artificial Neural Networks (ANNs), a method of artificial intelligence method, provide effective predictive models for complex processes. Three independent ANN models trained with back-propagation algorithm were developed to predict effluent chemical oxygen demand (COD), suspended solids (SS) and aeration tank mixed liquor suspended solids (MLSS) concentrations of the Ankara central wastewater treatment plant. The appropriate architecture of ANN models was determined through several steps of training and testing of the models. ANN models yielded satisfactory predictions. Results of the root mean square error, mean absolute error and mean absolute percentage error were 3.23, 2.41 mg/L and 5.03% for COD; 1.59, 1.21 mg/L and 17.10% for SS; 52.51, 44.91 mg/L and 3.77% for MLSS, respectively, indicating that the developed model could be efficiently used. The results overall also confirm that ANN modelling approach may have a great implementation potential for simulation, precise performance prediction and process control of wastewater treatment plants.

Differences in fluorescence characteristics and bioavailability of water-soluble organic matter (WSOM) in sediments and suspended solids in Lihu Lake, China.

Science.gov (United States)

Wang, Wenwen; Wang, Shuhang; Jiang, Xia; Zheng, Binghui; Zhao, Li; Zhang, Bo; Chen, Junyi

2018-05-01

The spectral characteristics, spatial distribution, and bioavailability of water-soluble organic matter (WSOM) in suspended solids and surface sediments of Lihu Lake, China, were investigated through excitation-emission matrix spectra and parallel factor analysis. The average content of dissolved organic carbon (DOC) in the sediments reached 643.28 ± 58.34 mg C/kg and that in suspended solids was 714.87 ± 69.24 mg C/kg. The fluorescence intensity of WSOM totaled 90.87 ± 5.65 and 115.42 ± 8.02 RU/g for the sediments and suspended solids, respectively. The DOC and fluorescence intensity of the WSOM showed an increasing trend moving from the west to the east of the lake. The WSOM in sediments and suspended solids contained two humic-like (C1 and C2) and one tryptophan-like (C3) components. These components had different fluorescent peaks and relative proportions. In the sediments, the relative proportions of C1, C2, and C3 were 33.71% ± 0.71, 26.83% ± 0.68, and 39.50% ± 0.71%, respectively. Meanwhile, C1 (35.77 ± 0.84%), C2 (34.07 ± 0.61%), and C3 (30.16 ± 0.75%) had similar relative percentages in suspended solids. The sediments had a lower humification index (3.02 ± 0.08) than the suspended solids (4.04 ± 0.15). Exchangeable nitrogen for the sediments and suspended solids was dominated by exchangeable ammonium nitrogen and soluble organic nitrogen, respectively. WSOM plays an important role in migration and transformation of nitrogen in sediments and suspended solids. The sediment-derived WSOM exhibited higher lability and biological activity than did the suspended solid-derived WSOM. The relative ratio of the intensity of protein-like fluorescent component to that of the humic-like one can be used as a reference index to evaluate the lability and biological activity of WSOM in sediments and suspended solids.

Development of a field test method for total suspended solids analysis.

Science.gov (United States)

2013-11-01

Total suspended solids (TSS) are all particles in water that will not pass through a glass fiber filter with a pore size less : than 2 m, including sediments, algae, nutrients, and metals. TSS is an important water quality parameter because of its ...

Comparison of specific oxygen uptake rates of two beach-scale ...

African Journals Online (AJOL)

The determined values of oxygen uptake rate during the endogenous reaction phase (between 0.1054 and 0.3564 mgO2/L.minute) and concentrations of mixed liquor suspended solids (between 1183 and 1957 mgMLSS/L) are comparable to those reported elsewhere in literature. Results of specific oxygen uptake rate of ...

Calibration of a turbidity meter for making estimates of total suspended solids concentrations and beam attenuation coefficients in field experiments

Science.gov (United States)

Usry, J. W.; Whitlock, C. H.

1981-01-01

Management of water resources such as a reservoir requires using analytical models which describe such parameters as the suspended sediment field. To select or develop an appropriate model requires making many measurements to describe the distribution of this parameter in the water column. One potential method for making those measurements expeditiously is to measure light transmission or turbidity and relate that parameter to total suspended solids concentrations. An instrument which may be used for this purpose was calibrated by generating curves of transmission measurements plotted against measured values of total suspended solids concentrations and beam attenuation coefficients. Results of these experiments indicate that field measurements made with this instrument using curves generated in this study should correlate with total suspended solids concentrations and beam attenuation coefficients in the water column within 20 percent.

Effect of the exposure to suspended solids on the enzymatic activity in the bivalve Sinonovacula constricta

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Guojun Yang

2017-01-01

Full Text Available Aquatic animals are susceptible to sudden changes of their living environment but they adopt strategies to cope with adverse environmental challenges. Contamination by suspended solids, often associated with a dramatic change in the concentrations of important water-quality variables is a frequent occurrence in China's coastal waters and estuaries. Here we studied the impact of suspended solids on the activities of the antioxidant enzymes superoxide dismutase (SOD and catalase (CAT, as well as adenosine triphosphates (including Na+ K+-ATPase, Mg+ +-ATPase, Ca+ +-ATPase and H+ K+-ATPase in the gills and visceral mass tissues of the molluscan bivalve Sinonovacula constricta exposed (4, 8, 12, 16, 20, and 24 days to various concentrations of suspended solids. Our results showed that the antioxidant enzymes cooperated closely to effectively scavenge superoxide anion free radicals and H2O2 (which can ultimately inhibit gill activity through the modification of SOD and/or CAT enzymatic activities. ATPases activity (considered to be a sensitive indicator of toxicity could play an effective role in the maintenance of functional integrity of the plasma membranes as well as some other intracellular functions. After the exposure, a decrease in the Na+ K+-ATPase, Mg+ +-ATPase, and Ca+ +-ATPase activity of the gills was observed suggesting that they were inhibited by the treatments. These results also indicated that, from day 4 to day 16, exposure to high concentrations of suspended solids had an inhibitory effect on the activity of H+-K+-ATPase in the visceral mass of S. constricta. However, after a period of adaptation the H+-K+-ATPase activity was restored to original levels. Our results suggest that long-term exposure to high levels of suspended solids disturb osmoregulation, gastric acid secretion and digestion, cause oxidative damage, as a consequence of antioxidant enzymes inactivation which eventually damages the gills, affect the food intake

Turbidity and total suspended solid concentration dynamics in streamflow from California oak woodland watersheds

Science.gov (United States)

David J. Lewis; Kenneth W. Tate; Randy A. Dahlgren; Jacob Newell

2002-01-01

Resource agencies, private landowners, and citizen monitoring programs utilize turbidity (water clarity) measurements as a water quality indicator for total suspended solids (TSS – mass of solids per unit volume) and other constituents in streams and rivers. The dynamics and relationships between turbidity and TSS are functions of watershed-specific factors and...

Characterization and morphology of solids suspended in rain water; Caracterizacion y morfologia de solidos suspendidos en agua de lluvia

Energy Technology Data Exchange (ETDEWEB)

Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Mexico D.F. (Mexico)

2000-07-01

This work presents the results obtained from the analysis of rain water in Mexico. The study treats over the characterization and morphology of the solids suspended in form of particles in the atmosphere. The solids suspended were obtained of the pluvial precipitations after these have been centrifuged. Subsequently of the separation, the particulate matter was analysed by Sem and X-ray dispersive energy.

Removal properties of human enteric viruses in a pilot-scale membrane bioreactor (MBR) process.

Science.gov (United States)

Miura, Takayuki; Okabe, Satoshi; Nakahara, Yoshihito; Sano, Daisuke

2015-05-15

In order to evaluate removal properties of human enteric viruses from wastewater by a membrane bioreactor (MBR), influent, anoxic and oxic mixed liquor, and membrane effluent samples were collected in a pilot-scale anoxic-oxic MBR process for 16 months, and concentrations of enteroviruses, norovirus GII, and sapoviruses were determined by real-time PCR using murine norovirus as a process control. Mixed liquor samples were separated into liquid and solid phases by centrifugation, and viruses in the bulk solution and those associated with mixed liquor suspended solids (MLSS) were quantified. Enteroviruses, norovirus GII, and sapoviruses were detected in the influent throughout the sampling period (geometrical mean, 4.0, 3.1, and 4.4 log copies/mL, respectively). Enterovirus concentrations in the solid phase of mixed liquor were generally lower than those in the liquid phase, and the mean log reduction value between influent and anoxic mixed liquor was 0.40 log units. In contrast, norovirus GII and sapovirus concentrations in the solid phase were equal to or higher than those in the liquid phase, and higher log reduction values (1.3 and 1.1 log units, respectively) were observed between influent and anoxic mixed liquor. This suggested that enteroviruses were less associated with MLSS than norovirus GII and sapoviruses, resulting in lower enterovirus removal in the activated sludge process. Enteroviruses and norovirus GII were detected in the MBR effluent but sapoviruses were not in any effluent samples. When MLSS concentration was reduced to 50-60% of a normal operation level, passages of enteroviruses and norovirus GII through a PVDF microfiltration membrane were observed. Since rejection of viruses by the membrane was not related to trans-membrane pressure which was monitored as a parameter of membrane fouling, the results indicated that adsorption to MLSS plays an important role in virus removal by an MBR, and removal properties vary by viruses reflecting different

Organics and Suspended Solids Removal from Hospital

Directory of Open Access Journals (Sweden)

Fakhri Y. Hmood

2013-05-01

Full Text Available The Sequencing Batch Reactor (SBR method is used for treating samples of waste water taken from hospitals in Mosul. Many run periods are used (6-24 hours for             6 months. It is found that the organics and suspended solids removal increase with increasing the period of run, it is in the range ( 96-82 % and ( 100-95 % respectively, while the pH values are nearly neutral (7.05 to 7.5.     BOD5 and SS concentrations of the effluent are within the limits of Iraqi standards,  40:30 mg/l respectively. Hence, SBR method could be used for treating hospitals, small factories and some  residential sectors waste waters.  

Suspended-sediment concentrations, loads, total suspended solids, turbidity, and particle-size fractions for selected rivers in Minnesota, 2007 through 2011

Science.gov (United States)

Ellison, Christopher A.; Savage, Brett E.; Johnson, Gregory D.

2014-01-01

Sediment-laden rivers and streams pose substantial environmental and economic challenges. Excessive sediment transport in rivers causes problems for flood control, soil conservation, irrigation, aquatic health, and navigation, and transports harmful contaminants like organic chemicals and eutrophication-causing nutrients. In Minnesota, more than 5,800 miles of streams are identified as impaired by the Minnesota Pollution Control Agency (MPCA) due to elevated levels of suspended sediment. The U.S. Geological Survey, in cooperation with the MPCA, established a sediment monitoring network in 2007 and began systematic sampling of suspended-sediment concentrations (SSC), total suspended solids (TSS), and turbidity in rivers across Minnesota to improve the understanding of fluvial sediment transport relations. Suspended-sediment samples collected from 14 sites from 2007 through 2011 indicated that the Zumbro River at Kellogg in the driftless region of southeast Minnesota had the highest mean SSC of 226 milligrams per liter (mg/L) followed by the Minnesota River at Mankato with a mean SSC of 193 mg/L. During the 2011 spring runoff, the single highest SSC of 1,250 mg/L was measured at the Zumbro River. The lowest mean SSC of 21 mg/L was measured at Rice Creek in the northern Minneapolis- St. Paul metropolitan area. Total suspended solids (TSS) have been used as a measure of fluvial sediment by the MPCA since the early 1970s; however, TSS concentrations have been determined to underrepresent the amount of suspended sediment. Because of this, the MPCA was interested in quantifying the differences between SSC and TSS in different parts of the State. Comparisons between concurrently sampled SSC and TSS indicated significant differences at every site, with SSC on average two times larger than TSS concentrations. The largest percent difference between SSC and TSS was measured at the South Branch Buffalo River at Sabin, and the smallest difference was observed at the Des Moines

Cost estimation and economical evaluation of three configurations of activated sludge process for a wastewater treatment plant (WWTP) using simulation

Science.gov (United States)

Jafarinejad, Shahryar

2017-09-01

The activated sludge (AS) process is a type of suspended growth biological wastewater treatment that is used for treating both municipal sewage and a variety of industrial wastewaters. Economical modeling and cost estimation of activated sludge processes are crucial for designing, construction, and forecasting future economical requirements of wastewater treatment plants (WWTPs). In this study, three configurations containing conventional activated sludge (CAS), extended aeration activated sludge (EAAS), and sequencing batch reactor (SBR) processes for a wastewater treatment plant in Tehran city were proposed and the total project construction, operation labor, maintenance, material, chemical, energy and amortization costs of these WWTPs were calculated and compared. Besides, effect of mixed liquor suspended solid (MLSS) amounts on costs of WWTPs was investigated. Results demonstrated that increase of MLSS decreases the total project construction, material and amortization costs of WWTPs containing EAAS and CAS. In addition, increase of this value increases the total operation, maintenance and energy costs, but does not affect chemical cost of WWTPs containing EAAS and CAS.

Assessment of conservation easements, total phosphorus, and total suspended solids in West Fork Beaver Creek, Minnesota, 1999-2012

Science.gov (United States)

Christensen, Victoria G.; Kieta, Kristen A.

2014-01-01

This study examined conservation easements and their effectiveness at reducing phosphorus and solids transport to streams. The U.S. Geological Survey cooperated with the Minnesota Board of Water and Soil Resources and worked collaboratively with the Hawk Creek Watershed Project to examine the West Fork Beaver Creek Basin in Renville County, which has the largest number of Reinvest In Minnesota land retirement contracts in the State (as of 2013). Among all conservation easement programs, a total of 24,218 acres of agricultural land were retired throughout Renville County, and 2,718 acres were retired in the West Fork Beaver Creek Basin from 1987 through 2012. Total land retirement increased steadily from 1987 until 2000. In 2000, land retirement increased sharply because of the Minnesota River Conservation Reserve Enhancement Program, then leveled off when the program ended in 2002. Streamflow data were collected during 1999 through 2011, and total phosphorus and total suspended solids data were collected during 1999 through 2012. During this period, the highest peak streamflow of 1,320 cubic feet per second was in March 2010. Total phosphorus and total suspended solids are constituents that tend to increase with increases in streamflow. Annual flow-weighted mean total-phosphorus concentrations ranged from 0.140 to 0.759 milligrams per liter, and annual flow-weighted mean total suspended solids concentrations ranged from 21.3 to 217 milligrams per liter. Annual flow-weighted mean total phosphorus and total suspended solids concentrations decreased steadily during the first 4 years of water-quality sample collection. A downward trend in flow-weighted mean total-phosphorus concentrations was significant from 1999 through 2008; however, flow-weighted total-phosphorus concentrations increased substantially in 2009, and the total phosphorus trend was no longer significant. The high annual flow-weighted mean concentrations for total phosphorus and total suspended solids

Suspended solids moderate the degradation and sorption of waste water-derived pharmaceuticals in estuarine waters.

Science.gov (United States)

Aminot, Yann; Fuster, Laura; Pardon, Patrick; Le Menach, Karyn; Budzinski, Hélène

2018-01-15

This study focuses on the fate of pharmaceuticals discharged into an estuarine environment, particularly into the Turbidity Maximum Zone (TMZ). Batch experiments were set up to investigate the factors regulating the degradation of 53 selected pharmaceuticals. Treated effluents from Bordeaux city (France) were mixed with water from the estuarine Garonne River during 4weeks under 6 characterized conditions in order to assess the influence of suspended particulates, sterilization, untreated wastewater input and dilution on the degradation kinetics. Of the 53 pharmaceuticals monitored, 43 were quantified at the initial time. Only 7 exhibited a persistent behavior (e.g. carbamazepine, meprobamate) while biotic degradation was shown to be the main attenuation process for 38 molecules (e.g. abacavir, ibuprofen highly degradable). Degradation was significantly enhanced by increasing concentrations of suspended solids. A persistence index based on the half-lives of the compounds has been calculated for each of the 43 pharmaceuticals to provide a practical estimate of their relative stability. The stability of pharmaceuticals in estuarine environments is likely to be highly variable and attenuated primarily by changes in suspended solid concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

Determination of radiocaesium in agriculture-related water samples containing suspended solids using gelling method

International Nuclear Information System (INIS)

Matsunami, Hisaya; Shin, Moono; Takahashi, Yoshihiko; Shinano, Takuro; Kitajima, Shiori; Tsuchiya, Takashi

2015-01-01

After the TEPCO Fukushima Dai-ichi Nuclear Power Plant accident in 2011, the radiocaesium, which flowed into the paddy fields via irrigation water, have been widely investigated. When the concentration of radiocaesium in the water samples containing suspended solids were directly measured using a high purity germanium detector with a 2 L marinelli beaker, the radiocaesium concentration might be overestimated due to the sedimentation of the suspended solids during the measurement time. In fact, the values obtained by the direct method were higher than those obtained by the filtering method and/or the gelling method in most of the agriculture-related water samples. We concluded that the gelling method using sodium polyacrylate can be widely adapted for the analysis of the total radiocaesium in the agriculture-related water samples because of its many advantage such as simple preparation procedure, accurate analysis values, excellent long-term stability of geometry and low operating cost. (author)

Temporal and spatial variations in total suspended and dissolved solids in the upper part of Manoa stream, Hawaii

NARCIS (Netherlands)

Augustijn, Dionysius C.M.; Fares, Ali; Tran, Dai Ngia

2011-01-01

Hawaiian watersheds are small, steep, and receive high intensity rainfall events of non-uniform distribution. These geographic and weather patterns result in flashy streams of strongly variable water quality even within various stream segments. Total suspended solids (TSS) and total dissolved solids

Resuspension and transport of suspended solids in Eurajoensalmi Bay. Final report of monitoring activities in 2009-2011

International Nuclear Information System (INIS)

Mykkanen, J.; Kiirikki, M.; Lindfors, A.

2012-11-01

The goal of monitoring activities carried out in Eurajoensalmi Bay was to indentify factors affecting dispersal of river waters and suspended solid matter in the estuary area. In addition to suspended solids load and dispersal of river water, also release of sedimented particles from the sea bed in resuspension was studied. River water quality and discharge as well as resuspension in Eurajoensalmi estuary area were monitored with Luode automatic monitoring stations equipped with water quality, water level, wave height and weather sensors. Dynamics of Eurajoensalmi estuary area was studied by installing profiling current meters (ADCP) and water quality sensors to the sea floor at the mouth of Eurajoensalmi. Spatial variation of surface water quality was monitored with a flow-through method from a moving vessel and manual profiling several times during the monitoring period. Collected data was processed and used in determining suspended solids balance of Eurajoensalmi Bay. The balance was determined by creating a regression model for water exchange and sediment flux over the cross section at the mouth of Eurajoensalmi. Regression model was created also to determine resuspension in Eurajoensalmi area. Sediment flux and resuspension were modeled using long term wind data from Kylmaepihlaja meteorological station as a variable to determine overall sediment balance of Eurajoensalmi

Bulk metal concentrations versus total suspended solids in rivers: Time-invariant & catchment-specific relationships.

Science.gov (United States)

Nasrabadi, Touraj; Ruegner, Hermann; Schwientek, Marc; Bennett, Jeremy; Fazel Valipour, Shahin; Grathwohl, Peter

2018-01-01

Suspended particles in rivers can act as carriers of potentially bioavailable metal species and are thus an emerging area of interest in river system monitoring. The delineation of bulk metals concentrations in river water into dissolved and particulate components is also important for risk assessment. Linear relationships between bulk metal concentrations in water (CW,tot) and total suspended solids (TSS) in water can be used to easily evaluate dissolved (CW, intercept) and particle-bound metal fluxes (CSUS, slope) in streams (CW,tot = CW + CSUS TSS). In this study, we apply this principle to catchments in Iran (Haraz) and Germany (Ammer, Goldersbach, and Steinlach) that show differences in geology, geochemistry, land use and hydrological characteristics. For each catchment, particle-bound and dissolved concentrations for a suite of metals in water were calculated based on linear regressions of total suspended solids and total metal concentrations. Results were replicable across sampling campaigns in different years and seasons (between 2013 and 2016) and could be reproduced in a laboratory sedimentation experiment. CSUS values generally showed little variability in different catchments and agree well with soil background values for some metals (e.g. lead and nickel) while other metals (e.g. copper) indicate anthropogenic influences. CW was elevated in the Haraz (Iran) catchment, indicating higher bioavailability and potential human and ecological health concerns (where higher values of CSUS/CW are considered as a risk indicator).

Experimental Design of Electrocoagulation and Magnetic Technology for Enhancing Suspended Solids Removal from Synthetic Wastewater

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Moh Faiqun Ni'am

2014-10-01

Full Text Available Design of experiments (DOE is one of the statistical method that is used as a tool to enhance and improve experimental quality. The changes to the variables of a process or system is supposed to give the optimal result (response and quite satisfactory. Experimental design can defined as a test or series of test series by varying the input variables (factors of a process that can known to cause changes in output (response. This paper presents the results of experimental design of wastewater treatment by electrocoagulation (EC technique. A combined magnet and electrocoagulation (EC technology were designed to increase settling velocity and to enhance suspended solid removal efficiencies from wastewater samples. In this experiment, a synthetic wastewater samples were prepared by mixing 700 mg of the milk powder in one litre of water and treated by using an acidic buffer solution. The monopolar iron (Fe plate anodes and cathodes were employed as electrodes. Direct current was varied in a range of between 0.5 and 1.1 A, and flowrate in a range of between 1.00 to 3.50 mL/s. One permanent magnets namely AlNiCo with a magnetic strength of 0.16T was used in this experiment. The results show that the magnetic field and the flowrate have major influences on suspended solids removal. The efficiency removals of suspended solids, turbidity and COD removal efficiencies at optimum conditions were found to be more than 85%, 95%, and 75%, respectively.

Comparing peracetic acid and hypochlorite for disinfection of combined sewer overflows: Effects of suspended-solids and pH.

Science.gov (United States)

McFadden, M; Loconsole, J; Schockling, A J; Nerenberg, R; Pavissich, J P

2017-12-01

Peracetic acid (PAA) is an alternative disinfectant that may be effective for combined sewer overflow (CSO) disinfection, but little is known about the effect of particle size on PAA disinfection efficiency. In this work, PAA and hypochlorite were compared as disinfectants, with a focus on the effect of wastewater particles. Inactivation experiments were conducted on suspended cultures of Escherichia coli and wastewater suspended solids. Tested size fractions included particle diameters disinfection efficiency decreased with increasing solids size. However, solids size had little effect on PAA disinfection. The PAA disinfection efficiency decreased at pH values above 7.5. Live/dead staining revealed that PAA disinfection leaves most cells in a viable but non-culturable condition. Fourier transform infrared spectroscopy (FTIR) analyses suggests that PAA and hypochlorite may inactivate E. coli bacteria by similar mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

Study on submerged anaerobic membrane bioreactor (SAMBR) treating high suspended solids raw tannery wastewater for biogas production.

Science.gov (United States)

Umaiyakunjaram, R; Shanmugam, P

2016-09-01

This study deals with the treatment of high suspended solids raw tannery wastewater using flat sheet Submerged Anaerobic Membrane (0.4μm) Bioreactor (SAMBR) acclimatized with hypersaline anaerobic seed sludge for recovering biogas. The treatability of SAMBR achieved higher CODremoval efficiency (90%) and biogas yield (0.160L.g(-1) CODremoved) coincided with high r(2) values between permeate flux and TSS (0.95), biogas and COD removed (0.96). The acidification of hypersaline influent wastewater by biogas mixing with high CO2, achieved quadruplet benefit of gas liquid and solid separation, in-situ pH and NH3 control, in-situ CH4 enrichment, and prevention of membrane fouling. The initial high VFA became stable as time elapsed reveals the hydrolysing ability of particulate COD into soluble COD and into biogas, confirms the suitability of SAMBR for high suspended solids tannery wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

Determination of the concentration of total suspends solids (TSS) and heavy metals in basin rio Morote, Nicoya, Guanacaste

International Nuclear Information System (INIS)

Sanchez Murillo, Ricardo; Leon, Sandra; Saravia, Ana Yuri; Mena Sanchez, Carlos de

2009-01-01

The total concentration of suspends solids and heavy metals were determined of the Basin of rio Morote. The study spanned six sampling campaigns between April 2003 and May 2005. Sampling points were selected to correspond to places from the high basin to the mouth of the rio Morote in the Golfo de Nicoya. Suspends total solids concentration (TSS) on average exceeds 200 mg/L during the rainy season at the mouth. Enrichment of metals as: Cu, Ni, Cd and Fe was found in riverbed sediments; but not in Pb. The concentration of Zn has been near the limit value (200 mg/kg) in the dry season, value which has been established for the Environmental Protection Agency of United States (EPA). (author) [es

Cost minimization in a full-scale conventional wastewater treatment plant: associated costs of biological energy consumption versus sludge production.

Science.gov (United States)

Sid, S; Volant, A; Lesage, G; Heran, M

2017-11-01

Energy consumption and sludge production minimization represent rising challenges for wastewater treatment plants (WWTPs). The goal of this study is to investigate how energy is consumed throughout the whole plant and how operating conditions affect this energy demand. A WWTP based on the activated sludge process was selected as a case study. Simulations were performed using a pre-compiled model implemented in GPS-X simulation software. Model validation was carried out by comparing experimental and modeling data of the dynamic behavior of the mixed liquor suspended solids (MLSS) concentration and nitrogen compounds concentration, energy consumption for aeration, mixing and sludge treatment and annual sludge production over a three year exercise. In this plant, the energy required for bioreactor aeration was calculated at approximately 44% of the total energy demand. A cost optimization strategy was applied by varying the MLSS concentrations (from 1 to 8 gTSS/L) while recording energy consumption, sludge production and effluent quality. An increase of MLSS led to an increase of the oxygen requirement for biomass aeration, but it also reduced total sludge production. Results permit identification of a key MLSS concentration allowing identification of the best compromise between levels of treatment required, biological energy demand and sludge production while minimizing the overall costs.

Quantifying suspended solids in small rivers using satellite data.

Science.gov (United States)

Isidro, Celso M; McIntyre, Neil; Lechner, Alex M; Callow, Ian

2018-09-01

The management of suspended solids and associated contaminants in rivers requires knowledge of sediment sources. In-situ sampling can only describe the integrated impact of the upstream sources. Empirical models that use surface reflectance from satellite images to estimate total suspended solid (TSS) concentrations can be used to supplement measurements and provide spatially continuous maps. However, there are few examples, especially in narrow, shallow and hydrologically dynamic rivers found in mountainous areas. A case study of the Didipio catchment in Philippines was used to address these issues. Four 5-m resolution RapidEye images, from between the years 2014 and 2016, and near-simultaneous ground measurements of TSS concentrations were used to develop a power law model that approximates the relationship between TSS and reflectance for each of four spectral bands. A second dataset using two 2-m resolution Pleiades-1A and a third using a 6-m resolution SPOT-6 image along with ground-based measurements, were consistent with the model when using the red band data. Using that model, encompassing data from all three datasets, gave an R 2 value of 65% and a root mean square error of 519mgL -1 . A linear relationship between reflectance and TSS exists from 1mgL -1 to approximately 500mgL -1 . In contrast, for TSS measurements between 500mgL -1 and 3580mgL -1 reflectance increases at a generally lower and more variable rate. The results were not sensitive to changing the pixel location within the vicinity of the ground sampling location. The model was used to generate a continuous map of TSS concentration within the catchment. Further ground-based measurements including TSS concentrations that are higher than 3580mgL -1 would allow the model to be developed and applied more confidently over the full relevant range of TSS. Copyright © 2018 Elsevier B.V. All rights reserved.

The use of hand-held 35 mm color infrared imagery for estimates of suspended solids - A progress report. [in water pollution monitoring

Science.gov (United States)

Miller, W. F.; Whisler, F. D.; Robinette, H. R.; Finnie, D.; Cannon, T.

1975-01-01

A cost-effective aerial surveillance technique is proposed for detection and identification of suspended solids which would be operational for both governmental monitoring organizations and private individuals operating catfish farms. Sixteen catfish ponds were flown daily for seven days using two hand-held 35 mm cameras with both Kodachrome X and Ektachrome infrared film. Hue, value, and chroma designations were recorded for each pond on each date by three interpreters, and the accepted color was that recorded by at least two of the interpreters, or if there was a three hue range, the median was accepted. Relations between suspended solids and color designations were analyzed graphically, and chroma was discarded due to an apparent lack of correlation. The data obtained were then analyzed by multiple regression. Significant correlations were revealed between hue and value and total and inorganic suspended solids. If perfected, this technique could be developed to sufficent accuracy for large-scale reconnaissance surveys to monitor the quality of rivers and streams.

Assessment of the contribution of sewer deposits to suspended solids loads in combined sewer systems during rain events.

Science.gov (United States)

Hannouche, A; Chebbo, G; Joannis, C

2014-04-01

Within the French observatories network SOERE "URBIS," databases of continuous turbidity measurements accumulating hundreds of events and many dry weather days are available for two sites with different features (Clichy in Paris and Ecully in Lyon). These measurements, converted into total suspended solids (TSS) concentration using TSS-turbidity relationships and combined with a model of runoff event mean concentration, enable the assessment of the contribution of sewer deposits to wet weather TSS loads observed at the outlet of the two watersheds. Results show that the contribution of sewer deposits to wet weather suspended solid's discharges is important but variable (between 20 and 80 % of the mass at the outlet depending on the event), including a site allegedly free of (coarse) sewer deposits. The uncertainties associated to these results are assessed too.

Concentration and flux of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids for monitored tributaries of Lake Champlain, 1990-2012

Science.gov (United States)

Medalie, Laura

2014-01-01

Annual and daily concentrations and fluxes of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids were estimated for 18 monitored tributaries to Lake Champlain by using the Weighted Regressions on Time, Discharge, and Seasons regression model. Estimates were made for 21 or 23 years, depending on data availability, for the purpose of providing timely and accessible summary reports as stipulated in the 2010 update to the Lake Champlain “Opportunities for Action” management plan. Estimates of concentration and flux were provided for each tributary based on (1) observed daily discharges and (2) a flow-normalizing procedure, which removed the random fluctuations of climate-related variability. The flux bias statistic, an indicator of the ability of the Weighted Regressions on Time, Discharge, and Season regression models to provide accurate representations of flux, showed acceptable bias (less than ±10 percent) for 68 out of 72 models for total and dissolved phosphorus, total nitrogen, and chloride. Six out of 18 models for total suspended solids had moderate bias (between 10 and 30 percent), an expected result given the frequently nonlinear relation between total suspended solids and discharge. One model for total suspended solids with a very high bias was influenced by a single extreme value; however, removal of that value, although reducing the bias substantially, had little effect on annual fluxes.

Optoelectronic system to measure the concentration and turbidity of suspended solids in the water

International Nuclear Information System (INIS)

Valente, E.S.

1984-01-01

The selection of the site where a nuclear power plant is to be built requires intensive study of the environmental conditions. This work presents the results reached on the development of a measurement system of suspended solids based on turbidity characteristics of the water. The system consists of an optical transducer composed of an emitter and a detector of infrared light, both solid state type, whose electrical signal is electronically treated. The equipment was calibrated and certified against turbidity and concentration standards in laboratory use. The obtained results indicate the reliability of the experimental method. The utilization of the equipment at the shore reinforces its flexibility and commodity of use. (author)

A passive collection system for whole size fractions in river suspended solids

International Nuclear Information System (INIS)

Takeshi Matsunaga; Takahiro Nakanishi; Mariko Atarashi-Andoh; Erina Takeuchi; Katsunori Tsuduki; Syusaku Nishimura; Jun Koarashi; Shigeyoshi Otosaka; Tsutomu Sato; Seiya Nagao

2015-01-01

In order to solve difficulties in collection of river suspended solids (SS) such as frequent observations during stochastic rainfall events, a simple passive collection system of SS has been developed. It is composed of sequentially connected two large-scale filter vessels. A portion of river water flows down into the filter vessels utilizing a natural drop of streambed. The system enable us to carry out long-term, unmanned SS collection. It is also compatible with dissolved component collection. Its performance was validated in a forested catchment by applying to radiocesium and stable carbon transport. (author)

Resuspended contaminated sediments cause sublethal stress to oysters: A biomarker differentiates total suspended solids and contaminant effects.

Science.gov (United States)

Edge, Katelyn J; Dafforn, Katherine A; Simpson, Stuart L; Ringwood, Amy H; Johnston, Emma L

2015-06-01

Resuspended contaminated sediments represent an important route of contaminant exposure for aquatic organisms. During resuspension events, filter-feeding organisms are exposed to contaminants, in both the dissolved form (at the gills) and the particulate form (in the digestive system). In addition, these organisms must manage the physical stress associated with an increase in total suspended solids (TSS). To date, few studies have experimentally compared the contributions to biological stress of contaminated and clean suspended solids. The authors mixed field-collected sediments (cellular biomarkers (lysosomal membrane stability, lipid peroxidation, and glutathione) were measured to evaluate sublethal toxicity. Lysosomal membrane stability was the most sensitive biomarker for distinguishing effects from resuspended contaminated sediments, as increasing amounts of contaminated TSS increased lysosomal membrane destabilization. The authors' results illustrate the importance of considering contaminant exposures from resuspended sediments when assessing the toxicity of contaminants to aquatic organisms. © 2015 SETAC.

A data reconnaissance on the effect of suspended-sediment concentrations on dissolved-solids concentrations in rivers and tributaries in the Upper Colorado River Basin

Science.gov (United States)

Tillman, Fred D.; Anning, David W.

2014-01-01

The Colorado River is one of the most important sources of water in the western United States, supplying water to over 35 million people in the U.S. and 3 million people in Mexico. High dissolved-solids loading to the River and tributaries are derived primarily from geologic material deposited in inland seas in the mid-to-late Cretaceous Period, but this loading may be increased by human activities. High dissolved solids in the River causes substantial damages to users, primarily in reduced agricultural crop yields and corrosion. The Colorado River Basin Salinity Control Program was created to manage dissolved-solids loading to the River and has focused primarily on reducing irrigation-related loading from agricultural areas. This work presents a reconnaissance of existing data from sites in the Upper Colorado River Basin (UCRB) in order to highlight areas where suspended-sediment control measures may be useful in reducing dissolved-solids concentrations. Multiple linear regression was used on data from 164 sites in the UCRB to develop dissolved-solids models that include combinations of explanatory variables of suspended sediment, flow, and time. Results from the partial t-test, overall likelihood ratio, and partial likelihood ratio on the models were used to group the sites into categories of strong, moderate, weak, and no-evidence of a relation between suspended-sediment and dissolved-solids concentrations. Results show 68 sites have strong or moderate evidence of a relation, with drainage areas for many of these sites composed of a large percentage of clastic sedimentary rocks. These results could assist water managers in the region in directing field-scale evaluation of suspended-sediment control measures to reduce UCRB dissolved-solids loading.

Fate of cocaine drug biomarkers in sewer system: the role of suspended solids in biotransformation and sorption

DEFF Research Database (Denmark)

Ramin, Pedram; Brock, Andreas Libonati; Polesel, Fabio

on the fate of illicit drugs in sewer systems. This study aims at assessing the role of suspended solids on the biotransformation and sorption in raw sewage of eight illicit drug biomarkers (cocaine, heroin, methadone, mephedrone, ketamine, methamphetamine, MDMA and THC and their urinary metabolites...

Application of nuclear techniques to the measurement of rock density and transport of solid particles suspended in rivers

International Nuclear Information System (INIS)

Seddiki, A.

1984-10-01

In order to better understand hydron phenomens in semi-arid regions characterized by torrential rains, we measured solid particles suspended to dums and in rivers. We also determined the density profile of a drilling and density of saline solutions. We designed an automatic nuclear gauge used for measuring the concentration of particles suspended to rivers. The installation, calibration and operations of a LABEN gauge were done in BENI SLIMANE on the 27th and 28th of February, 1984. The first results we obtained were received on the 24th of April, 1984

Controlling the COD removal of an A-stage pilot study with instrumentation and automatic process control.

Science.gov (United States)

Miller, Mark W; Elliott, Matt; DeArmond, Jon; Kinyua, Maureen; Wett, Bernhard; Murthy, Sudhir; Bott, Charles B

2017-06-01

The pursuit of fully autotrophic nitrogen removal via the anaerobic ammonium oxidation (anammox) pathway has led to an increased interest in carbon removal technologies, particularly the A-stage of the adsorption/bio-oxidation (A/B) process. The high-rate operation of the A-stage and lack of automatic process control often results in wide variations of chemical oxygen demand (COD) removal that can ultimately impact nitrogen removal in the downstream B-stage process. This study evaluated the use dissolved oxygen (DO) and mixed liquor suspended solids (MLSS) based automatic control strategies through the use of in situ on-line sensors in the A-stage of an A/B pilot study. The objective of using these control strategies was to reduce the variability of COD removal by the A-stage and thus the variability of the effluent C/N. The use of cascade DO control in the A-stage did not impact COD removal at the conditions tested in this study, likely because the bulk DO concentration (>0.5 mg/L) was maintained above the half saturation coefficient of heterotrophic organisms for DO. MLSS-based solids retention time (SRT) control, where MLSS was used as a surrogate for SRT, did not significantly reduce the effluent C/N variability but it was able to reduce COD removal variation in the A-stage by 90%.

Removal of Cs+, Sr2+, and Co2+ ions from the mixture of organics and suspended solids aqueous solutions by zeolites

International Nuclear Information System (INIS)

Fang, Xiang Hong; Fang, Fang; Lu, Chun Hai; Zheng, Lei

2017-01-01

Serving as an excellent adsorbent and inorganic ion exchanger in the water purification field, zeolite 4A has in this work presented a strong capability for purifying radioactive waste, such as Sr 2+ , Cs + , and Co 2+ in water. During the processes of decontamination and decommissioning of suspended solids and organics in low-level radioactive wastewater, the purification performance of zeolite 4A has been studied. Under ambient temperature and neutral condition, zeolite 4A absorbed simulated radionuclides such as Sr 2+ , Cs + , and Co 2+ with an absorption rate of almost 90%. Additionally, in alkaline condition, the adsorption percentage even approached 98.7%. After conducting research on suspended solids and organics of zeolite 4A for the treatment of radionuclides, it was found that the suspended clay was conducive to absorption, whereas the absorption of organics in solution was determined by the species of radionuclides and organics. Therefore, zeolite 4A has considerable potential in the treatment of radioactive wastewater

Performance of Submerged Membrane Bioreactor Combined with Powdered Activated Carbon Addition for the Treatment of an Industrial Wastewater

Directory of Open Access Journals (Sweden)

Tri Widjaja

2010-02-01

Full Text Available Membrane technology is one of the alternative solutions to overcome industrial wastewater treatment developed nowadays. The addition of PAC (Powdered Activated Carbon in the activated sludge using Submerged Membrane Adsorption Hybrid Bioreactor (SMAHBR is expected to increase the organic material removal. The purpose of this study was to determine the performance of submerged membrane bioreactor and activated carbon adsorption capacity of organic materials in wastewater. This study used SIER (Surabaya Industrial Estate Rungkut – Surabaya, Indonesia waste as activated sludge operated at Mixed Liquor Suspended Solid (MLSS concentrations of 8000 and 15000 mg/l, and Chemical Oxygen Demand (COD concentrations of 1500, 2500 mg/l, Sludge Retention Time (SRT of 10;20; and 30 days and activated carbon variables of 0%; 2.5%; 5%; 7.5%; 10%. The results showed that the fouling potential occurred at high MLSS where the COD removal occurred at PAC addition of 10% reaching 91.86%. High Soluble Microbial Product (SMP accumulation (± 10 mg/l occurred in short SRT and high MLSS concentration. PAC addition resulted in decreased microorganisms in the reactor and better effluent of SMAHBR, as a result, the performance of the submerged membrane bioreactor would be restored.

Contrasts between channels and backwaters in a large, floodplain river: Testing our understanding of nutrient cycling, phytoplankton abundance, and suspended solids dynamics

Science.gov (United States)

Houser, Jeff N.

2016-01-01

In floodplain rivers, variability in hydraulic connectivity interacts with biogeochemistry to determine the distribution of suspended and dissolved substances. Nutrient, chlorophyll a, and suspended solids data spanning longitudinal (5 study reaches across 1300 river km), lateral (main channel and backwaters), and temporal (1994–2011) gradients in the Upper Mississippi River (UMR) were used to examine the extent to which observed differences between the main channel and backwaters were consistent with expectations based on current understanding of biogeochemical processes in large rivers. For N and P, the results largely conformed to expectations. N concentrations were greater in the main channel than in the backwaters in 82 to 96% of the observations across river reaches. Maximum TP concentrations generally occurred in backwaters during summer, when backwater TP often exceeded that of the main channel. Flux of P from sediments may be a substantial source of water-column P in UMR backwaters in summer. The data for suspended solids and chlorophyll a suggest that some refinements are needed of our understanding of ecosystem processes in large rivers. During low-discharge conditions, concentrations of inorganic suspended solids often were greater in backwaters than in the main channel, suggesting the importance of sediment resuspension. Chlorophyll a concentrations were usually greater in backwaters than in the main channel, but exceptions indicate that phytoplankton abundance in the main channel of the UMR can sometimes be greater than is typically expected for large rivers.

Pyrosequencing reveals bacterial communities in unchlorinated drinking water distribution system: an integral study of bulk water, suspended solids, loose deposits, and pipe wall biofilm.

Science.gov (United States)

Liu, G; Bakker, G L; Li, S; Vreeburg, J H G; Verberk, J Q J C; Medema, G J; Liu, W T; Van Dijk, J C

2014-05-20

The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments

Pyrosequencing Reveals Bacterial Communities in Unchlorinated Drinking Water Distribution System: An Integral Study of Bulk Water, Suspended Solids, Loose Deposits, and Pipe Wall Biofilm

KAUST Repository

Liu, G.

2014-05-20

The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected. Analyzing the composition and correlation of bacterial communities from different phases helped us to locate where most of the bacteria are and understand the interactions among these phases. In the present study, the bacteria from four critical phases of an unchlorinated DWDS, including bulk water, pipe wall biofilm, suspended solids, and loose deposits, were quantified and identified by adenosine triphosphate analysis and pyrosequencing, respectively. The results showed that the bulk water bacteria (including the contribution of suspended solids) contributed less than 2% of the total bacteria. The bacteria associated with loose deposits and pipe wall biofilm that accumulated in the DWDS accounted for over 98% of the total bacteria, and the contributions of bacteria in loose deposits and pipe wall biofilm were comparable. Depending on the amount of loose deposits, its contribution can be 7-fold higher than the pipe wall biofilm. Pyrosequencing revealed relatively stable bacterial communities in bulk water, pipe wall biofilm, and suspended solids throughout the distribution system; however, the communities present in loose deposits were dependent on the amount of loose deposits locally. Bacteria within the phases of suspended solids, loose deposits, and pipe wall biofilm were similar in phylogenetic composition. The bulk water bacteria (dominated by Polaromonas spp.) were clearly different from the bacteria from the other three phases (dominated by Sphingomonas spp.). This study highlighted that the integral DWDS ecology should include contributions from all of the four phases, especially the bacteria harbored by loose deposits. The accumulation of loose deposits and the aging process create variable microenvironments

Characteristics of suspended solids affect bifenthrin toxicity to the calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi.

Science.gov (United States)

Parry, Emily; Lesmeister, Sarah; Teh, Swee; Young, Thomas M

2015-10-01

Bifenthrin is a pyrethroid pesticide that is highly toxic to aquatic invertebrates. The dissolved concentration is generally thought to be the best predictor of acute toxicity. However, for the filter-feeding calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi, ingestion of pesticide-bound particles could prove to be another route of exposure. The present study investigated bifenthrin toxicity to E. affinis and P. forbesi in the presence of suspended solids from municipal wastewater effluent and surface water of the San Francisco (CA, USA) Estuary. Suspended solids mitigated the toxicity of total bifenthrin to E. affinis and P. forbesi, but mortality was higher than what would be predicted from dissolved concentrations alone. The results indicate that the toxicity and bioavailability of particle-associated bifenthrin was significantly correlated with counts of 0.5-µm to 2-µm particle sizes. Potential explanations could include direct ingestion of bifenthrin-bound particles, changes in food consumption and feeding behavior, and physical contact with small particles. The complex interactions between pesticides and particles of different types and sizes demonstrate a need for future ecotoxicological studies to investigate the role of particle sizes on aquatic organisms. © 2015 SETAC.

An Evaluation of a Dual Coriolis Meter System for In-Line Monitoring of Suspended Solids Concentrations in Radioactive Slurries

International Nuclear Information System (INIS)

Hylton, T.D.

2000-01-01

The U.S. Department of Energy (DOE) has millions of gallons of radioactive liquid and sludge wastes stored in underground tanks at several of its sites. In order to comply with various regulations and to circumvent potential problems associated with tank integrity, these wastes must be retrieved from the tanks, transferred to treatment facilities (or other storage locations), and processed to stable waste forms. The sludge wastes will typically be mobilized by some mechanical means (e.g., mixer pump, submerged jet) and mixed with the respective supernatants to create slurries that can be transferred by pipeline to the desired destination. Depending on the DOE site, these slurries may be transferred up to six miles. Since the wastes are radioactive, it is critically important for the transfers to be made without plugging a pipeline. To reduce such a risk, the relevant properties of the slurry (e.g., density, suspended solids concentration, viscosity, and particle size distribution) should be determined to be within acceptable limits prior to transfer. These properties should also be continuously monitored and controlled within specified limits while the transfer is in progress. The baseline method for determining the transport properties of slurries involves sampling and analysis; however, this method is time-consuming, and costly, and it does not provide real-time information. In addition, personnel who collect and analyze the samples are exposed to radiation. It is also questionable as to whether a laboratory analyst can obtain representative aliquots from the sample jar for these solid-liquid mixtures. The alternative method for determining the transport properties is in-line analysis. An in-line instrument is one that is connected to the process, analyzes the slurry as it flows through or by the instrument, and provides the results within seconds. This instrument can provide immediate feedback to operators so that, when necessary, the operators can respond

Solid and suspended/dissolved waste (N, P, O) from rainbow trout (Oncorynchus mykiss)

DEFF Research Database (Denmark)

Dalsgaard, Anne Johanne Tang; Pedersen, Per Bovbjerg

2011-01-01

differences between the dietary treatment groups in the waste produced. On average, 48% of the ingestedNwas recovered in thewater (TANconstituting 64–79%of this)and7% inthesolids. In comparison, 1% of the ingested P was recovered in the water and 43% in the solids. A breakpoint value of 5.6 g standardized......Quantifying aquaculture waste into different waste fractions will make it possible to design different treatment setups for obtaining specific cleaning objectives. The aim of this study was therefore to measure “all” solid and suspended/dissolved (i.e. unsedimented) waste from juvenile rainbow...... trout (Oncorynchus mykiss) fed three commonly applied commercial diets, “all” waste referring to: total nitrogen (N), total ammonia nitrogen (TAN=NH3-N+NH4-N), total phosphorus (P), and organicmatter characterized by the chemical oxygen demand (COD) and the biological oxygen demand after 5 days (BOD5...

Distribution of Total Suspended Solids Concentration in a River

Directory of Open Access Journals (Sweden)

Ahmad Hanif Asyhar

2012-08-01

Full Text Available Disposal of either industrial or nonindustrial wastewater into a river has a potential to cause riverpollution. Because each load of wastewater discharged into a river contains physical, chemical, and biological parametersthat determine water quality, so that it can affect the dissolved oxygen concentration in a river. Therefore the conductedresearch was aimed to determine the pattern of pollutant dispersion in Surabaya River within the section that is closed tothe Karang Pilang Monitoring Station - Surabaya. Parameter used in this research was Total Suspended Solids (TSS. Themethod used was the finite volume method with Quadratic Upwind Interpolation Convective Kinematics (QUICK schemeby means of developing models of dispersion water pollutants in a river. The governing equation was controlled by the lawsof mass conservation, momentum conservation, and pollution transport equation. Further, these equations were solvedusing numerical calculation and followed by numerical simulation. From the numerical simulation results, it can beconcluded that the magnitude of pollutant dispersion is determined by the initial discharged TSS concentrations into theriver, however the longitudinal direction is more dominantly influenced than in lateral directions.

Occurrence and persistence of fungicides in bed sediments and suspended solids from three targeted use areas in the United States.

Science.gov (United States)

Smalling, Kelly L; Reilly, Timothy J; Sandstrom, Mark W; Kuivila, Kathryn M

2013-03-01

To document the environmental occurrence and persistence of fungicides, a robust and sensitive analytical method was used to measure 34 fungicides and an additional 57 current-use pesticides in bed sediments and suspended solids collected from areas of intense fungicide use within three geographic areas across the United States. Sampling sites were selected near or within agricultural research farms using prophylactic fungicides at rates and types typical of their geographic location. At least two fungicides were detected in 55% of the bed and 83% of the suspended solid samples and were detected in conjunction with herbicides and insecticides. Six fungicides were detected in all samples including pyraclostrobin (75%), boscalid (53%), chlorothalonil (41%) and zoxamide (22%). Pyraclostrobin, a strobilurin fungicide, used frequently in the United States on a variety of crops, was detected more frequently than p,p'-DDE, the primary degradate of p,p'-DDT, which is typically one of the most frequently occurring pesticides in sediments collected within highly agricultural areas. Maximum fungicide concentrations in bed sediments and suspended solids were 198 and 56.7 μg/kg dry weight, respectively. There is limited information on the occurrence, fate, and persistence of many fungicides in sediment and the environmental impacts are largely unknown. The results of this study indicate the importance of documenting the persistence of fungicides in the environment and the need for a better understanding of off-site transport mechanisms, particularly in areas where crops are grown that require frequent treatments to prevent fungal diseases. Published by Elsevier B.V.

Simultaneous nitrification-denitrification achieved by an innovative internal-loop airlift MBR: comparative study.

Science.gov (United States)

Li, Y Z; He, Y L; Ohandja, D G; Ji, J; Li, J F; Zhou, T

2008-09-01

This study assessed the performance of different single-stage continuous aerated submerged membrane bioreactors (MBR) for nitrogen removal. Almost complete nitrification was achieved in each MBR irrespective of operating mode and biomass system. Denitrification was found to be the rate-limiting step for total nitrogen (T-N) removal. The MBR with internal-loop airlift reactor (ALR) configuration performed better as regards T-N removal compared with continuous stirred-tank reactor (CSTR). It was demonstrated that simultaneous nitrification and denitrification (SND) is the mechanism leading to nitrogen removal and the contribution of microenvironment on SND is more remarkable for the MBRs with hybrid biomass. Macroenvironment analyses showed that gradient distribution of dissolved oxygen (DO) level in airlift MBRs imposed a significant effect on SND. Higher mixed liquor suspended solid (MLSS) concentration led to the improvement in T-N removal by enhancing anoxic microenvironment. Apparent nitrite accumulation coupled with higher nitrogen reduction was accomplished at MLSS concentration exceeded 12.6 g/L.

Removal of Cs{sup +}, Sr{sup 2+}, and Co{sup 2+} ions from the mixture of organics and suspended solids aqueous solutions by zeolites

Energy Technology Data Exchange (ETDEWEB)

Fang, Xiang Hong; Fang, Fang; Lu, Chun Hai [College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu (China); Zheng, Lei [Southwest University of Science and Technology, Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Mianyang (China)

2017-04-15

Serving as an excellent adsorbent and inorganic ion exchanger in the water purification field, zeolite 4A has in this work presented a strong capability for purifying radioactive waste, such as Sr{sup 2+}, Cs{sup +}, and Co{sup 2+} in water. During the processes of decontamination and decommissioning of suspended solids and organics in low-level radioactive wastewater, the purification performance of zeolite 4A has been studied. Under ambient temperature and neutral condition, zeolite 4A absorbed simulated radionuclides such as Sr{sup 2+}, Cs{sup +}, and Co{sup 2+} with an absorption rate of almost 90%. Additionally, in alkaline condition, the adsorption percentage even approached 98.7%. After conducting research on suspended solids and organics of zeolite 4A for the treatment of radionuclides, it was found that the suspended clay was conducive to absorption, whereas the absorption of organics in solution was determined by the species of radionuclides and organics. Therefore, zeolite 4A has considerable potential in the treatment of radioactive wastewater.

Chemical composition shape form and size of suspended solids in the atmosphere carried by rain water

International Nuclear Information System (INIS)

Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la

2001-01-01

The interest of this work is to know about shape form, size and chemical composition of the suspended solids in the atmosphere of Toluca city and which are carried by the rains. The harvest of the samples was carried out during january to november 1999. The separation of the particulate matter from the rain water was realized through centrifugation. The solids were analysed by Scanning Electron Microscopy to know the shape form and size and the chemical composition was determined by X-ray dispersive energy in general form and of some particles individually analysed. The p H was measured to the solutions and the quantification of some dissolved ions by the Icp technique was realized. The results of the solids showed C, O, Na, Mg, Al, Si, S, P, K, Ca, Ti and Fe. Moreover they present sizes which varying from a ten of nanometers until some tens of microns. (Author)

Factors influencing suspended solids concentrations in activated sludge settling tanks.

Science.gov (United States)

Kim, Y; Pipes, W O

1999-05-31

A significant fraction of the total mass of sludge in an activated sludge process may be in the settling tanks if the sludge has a high sludge volume index (SVI) or when a hydraulic overload occurs during a rainstorm. Under those conditions, an accurate estimate of the amount of sludge in the settling tanks is needed in order to calculate the mean cell residence time or to determine the capacity of the settling tanks to store sludge. Determination of the amount of sludge in the settling tanks requires estimation of the average concentration of suspended solids in the layer of sludge (XSB) in the bottom of the settling tanks. A widely used reference recommends averaging the concentrations of suspended solids in the mixed liquor (X) and in the underflow (Xu) from the settling tanks (XSB=0. 5{X+Xu}). This method does not take into consideration other pertinent information available to an operator. This is a report of a field study which had the objective of developing a more accurate method for estimation of the XSB in the bottom of the settling tanks. By correlation analysis, it was found that only 44% of the variation in the measured XSB is related to sum of X and Xu. XSB is also influenced by the SVI, the zone settling velocity at X and the overflow and underflow rates of the settling tanks. The method of averaging X and Xu tends to overestimate the XSB. A new empirical estimation technique for XSB was developed. The estimation technique uses dimensionless ratios; i.e., the ratio of XSB to Xu, the ratio of the overflow rate to the sum of the underflow rate and the initial settling velocity of the mixed liquor and sludge compaction expressed as a ratio (dimensionless SVI). The empirical model is compared with the method of averaging X and Xu for the entire range of sludge depths in the settling tanks and for SVI values between 100 and 300 ml/g. Since the empirical model uses dimensionless ratios, the regression parameters are also dimensionless and the model can be

The clam (Chamelea gallina: evaluation of the effects of solids suspended in seawater on bivalve molluscs

Directory of Open Access Journals (Sweden)

Salvatora Angela Angioni

2010-03-01

Full Text Available The study was designed to evaluate the effects of solids in suspension in seawater on clams (Chamelea gallina. The aim was to investigate the possible correlation between the widespread deaths of clams in the coastal waters of the central and northern Adriatic in the last five years and increased concentrations of solids in suspension. The research involved conducting 96-hour tests on clams farmed in aquariums containing filtered seawater. The tests were preceded by a 7-day adaptation stage to allow the molluscs to acclimatise. During this period, the clams were fed on unicellular seaweed (Dunaliella tertiolecta. The molluscs were exposed to particles of solids in suspension consisting of pools of silica gel (SiO2 granules of various sizes, similar to those constituting silt, whose presence and suspension in the sea considerably increase after heavy rain and heavy seas. The study established that the number of deaths caused by solids suspended in seawater at the concentrations used in the tests was not statistically significant.

Resuspension and transport of suspended solids in Eurajoensalmi Bay. Final report of monitoring activities in 2009-2011; Resuspensio ja kiintoaineen kulkeutuminen Eurajoensalmessa. Vesistoemittausten loppuraportti

Energy Technology Data Exchange (ETDEWEB)

Mykkanen, J.; Kiirikki, M.; Lindfors, A. [Luode Consulting Oy, Espoo (Finland)

2012-11-15

The goal of monitoring activities carried out in Eurajoensalmi Bay was to indentify factors affecting dispersal of river waters and suspended solid matter in the estuary area. In addition to suspended solids load and dispersal of river water, also release of sedimented particles from the sea bed in resuspension was studied. River water quality and discharge as well as resuspension in Eurajoensalmi estuary area were monitored with Luode automatic monitoring stations equipped with water quality, water level, wave height and weather sensors. Dynamics of Eurajoensalmi estuary area was studied by installing profiling current meters (ADCP) and water quality sensors to the sea floor at the mouth of Eurajoensalmi. Spatial variation of surface water quality was monitored with a flow-through method from a moving vessel and manual profiling several times during the monitoring period. Collected data was processed and used in determining suspended solids balance of Eurajoensalmi Bay. The balance was determined by creating a regression model for water exchange and sediment flux over the cross section at the mouth of Eurajoensalmi. Regression model was created also to determine resuspension in Eurajoensalmi area. Sediment flux and resuspension were modeled using long term wind data from Kylmaepihlaja meteorological station as a variable to determine overall sediment balance of Eurajoensalmi.

Comparison between thermo balance and classic gravimetric method for determination of suspended solids in sludge from wastewater treatment plant

International Nuclear Information System (INIS)

Bruzzone, E.

2009-01-01

In this paper two methods for determination of suspended solids in sludge from wastewater treatment plants (activated, thickened and dry, in a range from 0.1 to 20-25%) are compared. Results are similar from statistic point of view between classic gravimetric method and thermo balance method. However the later seems better for its rapid and easy execution. [it

Characterization of suspended solids and total phosphorus loadings from small watersheds in Wisconsin

Science.gov (United States)

Danz, Mari E.; Corsi, Steven R.; Graczyk, David J.; Bannerman, Roger T.

2010-01-01

Knowledge of the daily, monthly, and yearly distribution of contaminant loadings and streamflow can be critical for the successful implementation and evaluation of water-quality management practices. Loading data for solids (suspended sediment and total suspended solids) and total phosphorus and streamflow data for 23 watersheds were summarized for four ecoregions of Wisconsin: the Driftless Area Ecoregion, the Northern Lakes and Forests Ecoregion, the North Central Hardwoods Ecoregion, and the Southeastern Wisconsin Till Plains Ecoregion. The Northern Lakes and Forests and the North Central Hardwoods Ecoregions were combined into one region for analysis due to a lack of sufficient data in each region. Urban watersheds, all located in the Southeastern Wisconsin Till Plains, were analyzed separately from rural watersheds as the Rural Southeastern Wisconsin Till Plains region and the Urban Southeastern Wisconsin Till Plains region. Results provide information on the distribution of loadings and streamflow between base flow and stormflow, the timing of loadings and streamflow throughout the year, and information regarding the number of days in which the majority of the annual loading is transported. The average contribution to annual solids loading from stormflow periods for the Driftless Area Ecoregion was 84 percent, the Northern Lakes and Forests/North Central Hardwoods region was 71 percent, the Rural Southeastern Wisconsin Till Plains region was 70 percent, and the Urban Southeastern Wisconsin Till Plains region was 90 percent. The average contributions to annual total phosphorus loading from stormflow periods were 72, 49, 61, and 76 percent for each of the respective regions. The average contributions to annual streamflow from stormflow periods are 20, 23, 31, and 50 percent for each of the respective regions. In all regions, the most substantial loading contributions for solids were in the late winter (February through March), spring (April through May), and

Genome?resolved metagenomics of a bioremediation system for degradation of thiocyanate in mine water containing suspended solid tailings

OpenAIRE

Rahman, Sumayah F.; Kantor, Rose S.; Huddy, Robert; Thomas, Brian C.; van Zyl, Andries W.; Harrison, Susan T.L.; Banfield, Jillian F.

2017-01-01

Abstract Thiocyanate (SCN?) is a toxic compound that forms when cyanide (CN?), used to recover gold, reacts with sulfur species. SCN??degrading microbial communities have been studied, using bioreactors fed synthetic wastewater. The inclusion of suspended solids in the form of mineral tailings, during the development of the acclimatized microbial consortium, led to the selection of an active planktonic microbial community. Preliminary analysis of the community composition revealed reduced mic...

The Applicability of the Distribution Coefficient, KD, Based on Non-Aggregated Particulate Samples from Lakes with Low Suspended Solids Concentrations.

Directory of Open Access Journals (Sweden)

Aine Marie Gormley-Gallagher

Full Text Available Separate phases of metal partitioning behaviour in freshwater lakes that receive varying degrees of atmospheric contamination and have low concentrations of suspended solids were investigated to determine the applicability of the distribution coefficient, KD. Concentrations of Pb, Ni, Co, Cu, Cd, Cr, Hg and Mn were determined using a combination of filtration methods, bulk sample collection and digestion and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS. Phytoplankton biomass, suspended solids concentrations and the organic content of the sediment were also analysed. By distinguishing between the phytoplankton and (inorganic lake sediment, transient variations in KD were observed. Suspended solids concentrations over the 6-month sampling campaign showed no correlation with the KD (n = 15 for each metal, p > 0.05 for Mn (r2 = 0.0063, Cu (r2 = 0.0002, Cr (r2 = 0.021, Ni (r2 = 0.0023, Cd (r2 = 0.00001, Co (r2 = 0.096, Hg (r2 = 0.116 or Pb (r2 = 0.164. The results implied that colloidal matter had less opportunity to increase the dissolved (filter passing fraction, which inhibited the spurious lowering of KD. The findings conform to the increasingly documented theory that the use of KD in modelling may mask true information on metal partitioning behaviour. The root mean square error of prediction between the directly measured total metal concentrations and those modelled based on the separate phase fractions were ± 3.40, 0.06, 0.02, 0.03, 0.44, 484.31, 80.97 and 0.1 μg/L for Pb, Cd, Mn, Cu, Hg, Ni, Cr and Co respectively. The magnitude of error suggests that the separate phase models for Mn and Cu can be used in distribution or partitioning models for these metals in lake water.

Pyrosequencing Reveals Bacterial Communities in Unchlorinated Drinking Water Distribution System: An Integral Study of Bulk Water, Suspended Solids, Loose Deposits, and Pipe Wall Biofilm

KAUST Repository

Liu, G.; Bakker, G. L.; Li, S.; Vreeburg, J. H G; Verberk, J. Q J C; Medema, G. J.; Liu, W. T.; Van Dijk, J. C.

2014-01-01

The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected

Electrodialytic extraction of Cu, Pb and Cl from municipal solid waste incineration fly ash suspended in water

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Lima, Ana Teresa; Pedersen, Anne Juul

2006-01-01

that is least soluble. Hence electrodialytic treatment of the ash suspended in water is not a solution to improve the ash quality in terms of Pb. The water-soluble Cl content per unit weight of the original ash was 12.4%. The removal of water-soluble Cl was efficient and >98% of Cl was removed (calculated......The possibility of using fly ash from municipal solid waste incineration (MSWI) in, for example, concrete is considered. MSWI fly ash, however, has too high a concentration of heavy metals, which may cause leaching problems during use or problems with waste handling at the end of the lifetime...... of the concrete. The Cl content in MSWI fly ash is also too high and will cause corrosion problems in reinforced concrete. The possibility of removing some of the unwanted heavy metals (Cu and Pb) together with Cl from an MSWI fly ash suspended in water using an electrodialytic separation method was investigated...

Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor.

Science.gov (United States)

Sahar, E; Ernst, M; Godehardt, M; Hein, A; Herr, J; Kazner, C; Melin, T; Cikurel, H; Aharoni, A; Messalem, R; Brenner, A; Jekel, M

2011-01-01

The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8-10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin - at an MLSS of 6-9 g/L - showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected.

Analysis of suspended solids transport processes in primary settling tanks.

Science.gov (United States)

Patziger, Miklós; Kiss, Katalin

2015-01-01

The paper shows the results of a long-term research comprising FLUENT-based numerical modeling, in situ measurements and laboratory tests to analyze suspended solids (SS) transport processes in primary settling tanks (PSTs). The investigated PST was one of the rectangular horizontal flow PSTs at a large municipal wastewater treatment plant (WWTP) of a capacity of 500,000 population equivalent. Many middle-sized and large WWTPs are equipped with such PSTs. The numerical PST model was calibrated and validated based on the results of comprehensive in situ flow and SS concentration measurements from low (5 m/h) up to quite high surface overflow rates of 9.5 and 13.0 m/h and on settling and other laboratory tests. The calibrated and validated PST model was also successfully used for evaluation of some slight modifications of the inlet geometry (removing lamellas, installing a flocculation 'box', shifting the inlet into a 'bottom-near' or into a 'high' position), which largely affect PST behavior and performance. The investigations provided detailed insight into the flow and SS transport processes within the investigated PST, which strongly contributes to hydrodynamically driven design and upgrading of PSTs.

Using total suspended solids (TSS) and turbidity as proxies for evaluation of metal transport in river water

International Nuclear Information System (INIS)

Nasrabadi, T.; Ruegner, H.; Sirdari, Z.Z.; Schwientek, M.; Grathwohl, P.

2016-01-01

The present study was carried out in Haraz basin (Iran) that is located in south of the Caspian Sea. The goal of this study was to establish correlations amongst total suspended solids concentration (TSS) and turbidity with total pollutant concentrations to evaluate the dissolved and particle-bound concentrations of major toxic metals. It also aimed to validate TSS and/or turbidity measurements as proxies to monitor pollutant fluxes. Eight metals, namely nickel, lead, cadmium, copper, zinc, cobalt, arsenic and strontium were analyzed for dissolved and total concentrations in water at ten locations within the catchment. TSS and turbidity were also measured. Sampling campaigns were designed to cover both the rainy (December) and the dry (May) season within the basin. The robust relationship between TSS (202–1212 mg/l) and turbidity (63–501 NTUs) in both seasons warranted their interchangeable potential as proxies within the observed ranges. Total element concentrations were plotted in separate attempts versus TSS and turbidity for all locations and both events. Very good linear correlations were attained where the slopes represent the metals concentration on suspended solids and the intercept the dissolved concentration in water. The results achieved by these linear regressions were in very good agreement with independently measured values for dissolved concentration and concentrations on river bed sediments taken at the same locations. This demonstrates that turbidity and/or TSS measurements may be used for monitoring of metal loads if once calibrated against total concentration of metals. The results also revealed that in the lower Haraz catchment metal concentrations on suspended and river bed sediment were homogeneously distributed along the investigated river stretch. This is assumed to be due to intensive gravel and sand mining activities in the upper and middle part of the catchment. - Highlights: • Turbidity is evaluated as a feasible proxy to predict

A method and algorithm for correlating scattered light and suspended particles in polluted water

International Nuclear Information System (INIS)

Sami Gumaan Daraigan; Mohd Zubir Matjafri; Khiruddin Abdullah; Azlan Abdul Aziz; Abdul Aziz Tajuddin; Mohd Firdaus Othman

2005-01-01

An optical model has been developed for measuring total suspended solids TSS concentrations in water. This approach is based on the characteristics of scattered light from the suspended particles in water samples. An optical sensor system (an active spectrometer) has been developed to correlate pollutant (total suspended solids TSS) concentration and the scattered radiation. Scattered light was measured in terms of the output voltage of the phototransistor of the sensor system. The developed algorithm was used to calculate and estimate the concentrations of the polluted water samples. The proposed algorithm was calibrated using the observed readings. The results display a strong correlation between the radiation values and the total suspended solids concentrations. The proposed system yields a high degree of accuracy with the correlation coefficient (R) of 0.99 and the root mean square error (RMS) of 63.57 mg/l. (Author)

Remote sensing and water quality indicators in the Korean West coast: Spatio-temporal structures of MODIS-derived chlorophyll-a and total suspended solids.

Science.gov (United States)

Kim, Hae-Cheol; Son, Seunghyun; Kim, Yong Hoon; Khim, Jong Seong; Nam, Jungho; Chang, Won Keun; Lee, Jung-Ho; Lee, Chang-Hee; Ryu, Jongseong

2017-08-15

The Yellow Sea is a shallow marginal sea with a large tidal range. In this study, ten areas located along the western coast of the Korean Peninsula are investigated with respect to remotely sensed water quality indicators derived from NASA MODIS aboard of the satellite Aqua. We found that there was a strong seasonal trend with spatial heterogeneity. In specific, a strong six-month phase-lag was found between chlorophyll-a and total suspended solid owing to their inversed seasonality, which could be explained by different dynamics and environmental settings. Chlorophyll-a concentration seemed to be dominantly influenced by temperature, while total suspended solid was largely governed by local tidal forcing and bottom topography. This study demonstrated the potential and applicability of satellite products in coastal management, and highlighted find that remote-sensing would be a promising tool in resolving orthogonality of large spatio-temporal scale variabilities when combining with proper time series analyses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Control of membrane fouling during hyperhaline municipal wastewater treatment using a pilot-scale anoxic/aerobic-membrane bioreactor system

Institute of Scientific and Technical Information of China (English)

Jingmei Sun; Jiangxiu Rong; Lifeng Dai; Baoshan Liu; Wenting Zhu

2011-01-01

Membrane fouling limits the effects of long-term stable operation of membrane bioreactor (MBR).Control of membrane foulin can extend the membrane life and reduce water treatment cost effectively.A pilot scale anoxic/aerobic-membrane bioreactor (A/O MBR,40 L/hr) was used to treat the hyperhaline municipal sewage from a processing zone of Tianjin,China.Impact factors including mixed liquid sludge suspension (MLSS),sludge viscosity (μ),microorganisms,extracellular polymeric substances (EPS),aeration intensity and suction/suspended time on membrane fouling and pollution control were studied.The relationships among various factors associated with membrane fouling were analyzed.Results showed that there was a positive correlation among MLSS,sludge viscosity and trans-membrane pressure (TMP).Considering water treatment efficiency and stable operation of the membrane module,MLSS of 5 g/L was suggested for the process.There was a same trend among EPS,sludge viscosity and TMP.Numbers and species of microorganisms affected membrane fouling.Either too high or too low aeration intensity was not conducive to membrane fouling control.Aeration intensity of 1.0 m3/hr (gas/water ratio of 25:1) is suggested for the process.A long suction time caused a rapid increase in membrane resistance.However,long suspended time cannot prevent the increase of membrane resistance effectively even though a suspended time was necessary for scale off particles from the membrane surface.The suction/suspended time of 12 min/3 min was selected for the process.The interaction of various environmental factors and operation conditions must be considered synthetically.

Impact of catastrophic events on small mountainous rivers: Temporal and spatial variations in suspended- and dissolved-solid fluxes along the Choshui River, central western Taiwan, during typhoon Mindulle, July 2-6, 2004

Science.gov (United States)

Milliman, J. D.; Lee, T. Y.; Huang, J. C.; Kao, S. J.

2017-05-01

Small mountainous rivers deliver disproportionately large quantities of suspended and dissolved solids to the global ocean, often in response to catastrophic events such as earthquakes or floods. Here we report on the impact of a major flood on the Choshui River, central-western Taiwan, generated by typhoon Mindulle, July 2-6, 2004, five years after the nearby Mw 7.6 Chichi earthquake. Water samples taken at 3-h intervals at three stations along main stem, as well as from two downriver tributaries, allow us to delineate the temporal and spatial variability in concentrations and fluxes of suspended and dissolved constituents within the middle and lower portions of the river in response to this flood. High suspended-sediment concentrations, some as high as 200 g/l, reflected the rapid erosion of landslide scars and debris deposits generated by super-typhoon Herb in 1996 and the 1999 Chichi earthquake. Dissolved-solid and suspended-sediment discharges totaled 0.22 and 70 million tons (mt), 50 mt of which were discharged in just two days. Particulate organic carbon (POC) discharge, most of which was pre-modern in age, was 195,000 t. More than half of the discharged water, POC and dissolved solids came from upriver, whereas about 70% of the suspended sediment and 60% of the dissolved nitrate came from two downriver tributaries, the Chenyoulan and Qingshui rivers. Spatial and temporal differences in the character and discharge of suspended and dissolved solids within and between rivers in the Choshui drainage basin reflect different geologies, landslide histories, the effects of human impact, and the abrupt draining of the Tsaoling landslide lake in the Qingshui basin, as well as the possible shifting of importance of groundwater vs. overland flow. Neither wind-blown pollutants nor sea salts appear to have contributed significantly to dissolved solid character or discharge. Sediment contribution from the landslides in the Chenyoulan basin generated by super-typhoon Herb

Evaluating the Efficiency of Tragacanth Coagulant Aid in Removing Colloidal Materials and Suspended Solids Creating Turbidity from Karun River Water

OpenAIRE

Majid Farhadi; Afshin Takdastan; Roghayeh Baghbany

2016-01-01

Introduction: Colloidal materials and suspended solids cause turbidity in water. To remove turbidity, clarification method is used that includes processes of coagulation, flocculation, and sedimentation. Due to the long duration of coagulation process, coagulant aids are applied. Despite the favorable efficiency of synthetic polyelectrolytes as a coagulant aid, due to their harmful effects on human health, in this process, natural organic polymers are used instead. Materials and Methods: I...

Evaluation of stream water quality data generated from MODIS images in modeling total suspended solid emission to a freshwater lake.

Science.gov (United States)

Ayana, Essayas K; Worqlul, Abeyou W; Steenhuis, Tammo S

2015-08-01

Modeling of suspended sediment emission into freshwater lakes is challenging due to data gaps in developing countries. Existing models simulate sediment concentration at a gauging station upstream and none of these studies had modeled total suspended solids (TSS) emissions by inflowing rivers to freshwater lakes as there are no TSS measurements at the river mouth in the upper Blue Nile basin. In this study a 10year TSS time series data generated from remotely sensed MODIS/Terra images using established empirical relationship is applied to calibrate and validate a hydrology model for Lake Tana in Upper Blue Nile Basin. The result showed that at a monthly time scale TSS at the river mouth can be replicated with Nash-Sutcliffe efficiency (NS) of 0.34 for calibration and 0.21 for validation periods. Percent bias (PBIAS) and ratio of the root-mean-square error to the standard deviation of measured data (RSR) are all within range. Given the inaccessibility and costliness to measure TSS at river mouths to a lake the results found here are considered useful for suspended sediment budget studies in water bodies of the basin. Copyright © 2015 Elsevier B.V. All rights reserved.

Electrodialytic remediation of suspended mine tailings

DEFF Research Database (Denmark)

Hansen, Henrik K.; Rojo, Adrian; Pino, Denisse

2008-01-01

This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. A newly designed remediation cell, where the solids were kept in suspension by airflow, was tested. The results show that electric current could remove copper from suspended tailings...... efficiency from 1% to 80% compared to experiments with no stirring but with the same operational conditions. This showed the crucial importance of having the solids in suspension and not settled during the remediation....

Concentration, flux, and trend estimates with uncertainty for nutrients, chloride, and total suspended solids in tributaries of Lake Champlain, 1990–2014

Science.gov (United States)

Medalie, Laura

2016-12-20

The U.S. Geological Survey, in cooperation with the New England Interstate Water Pollution Control Commission and the Vermont Department of Environmental Conservation, estimated daily and 9-month concentrations and fluxes of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids from 1990 (or first available date) through 2014 for 18 tributaries of Lake Champlain. Estimates of concentration and flux, provided separately in Medalie (2016), were made by using the Weighted Regressions on Time, Discharge, and Season (WRTDS) regression model and update previously published WRTDS model results with recent data. Assessment of progress towards meeting phosphorus-reduction goals outlined in the Lake Champlain management plan relies on annual estimates of phosphorus flux. The percent change in annual concentration and flux is provided for two time periods. The R package EGRETci was used to estimate the uncertainty of the trend estimate. Differences in model specification and function between this study and previous studies that used WRTDS to estimate concentration and flux using data from Lake Champlain tributaries are described. Winter data were too sparse and nonrepresentative to use for estimates of concentration and flux but were sufficient for estimating the percentage of total annual flux over the period of record. Median winter-to-annual fractions ranged between 21 percent for total suspended solids and 27 percent for dissolved phosphorus. The winter contribution was largest for all constituents from the Mettawee River and smallest from the Ausable River. For the full record (1991 through 2014 for total and dissolved phosphorus and chloride and 1993 through 2014 for nitrogen and total suspended solids), 6 tributaries had decreasing trends in concentrations of total phosphorus, and 12 had increasing trends; concentrations of dissolved phosphorus decreased in 6 and increased in 8 tributaries; fluxes of total phosphorus decreased in 5 and

Turbidity and Total Suspended Solids on the Lower Cache River Watershed, AR.

Science.gov (United States)

Rosado-Berrios, Carlos A; Bouldin, Jennifer L

2016-06-01

The Cache River Watershed (CRW) in Arkansas is part of one of the largest remaining bottomland hardwood forests in the US. Although wetlands are known to improve water quality, the Cache River is listed as impaired due to sedimentation and turbidity. This study measured turbidity and total suspended solids (TSS) in seven sites of the lower CRW; six sites were located on the Bayou DeView tributary of the Cache River. Turbidity and TSS levels ranged from 1.21 to 896 NTU, and 0.17 to 386.33 mg/L respectively and had an increasing trend over the 3-year study. However, a decreasing trend from upstream to downstream in the Bayou DeView tributary was noted. Sediment loading calculated from high precipitation events and mean TSS values indicate that contributions from the Cache River main channel was approximately 6.6 times greater than contributions from Bayou DeView. Land use surrounding this river channel affects water quality as wetlands provide a filter for sediments in the Bayou DeView channel.

Stochastic modeling of total suspended solids (TSS) in urban areas during rain events.

Science.gov (United States)

Rossi, Luca; Krejci, Vladimir; Rauch, Wolfgang; Kreikenbaum, Simon; Fankhauser, Rolf; Gujer, Willi

2005-10-01

The load of total suspended solids (TSS) is one of the most important parameters for evaluating wet-weather pollution in urban sanitation systems. In fact, pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), phosphorous and organic compounds are adsorbed onto these particles so that a high TSS load indicates the potential impact on the receiving waters. In this paper, a stochastic model is proposed to estimate the TSS load and its dynamics during rain events. Information on the various simulated processes was extracted from different studies of TSS in urban areas. The model thus predicts the probability of TSS loads arising from combined sewer overflows (CSOs) in combined sewer systems as well as from stormwater in separate sewer systems in addition to the amount of TSS retained in treatment devices in both sewer systems. The results of this TSS model illustrate the potential of the stochastic modeling approach for assessing environmental problems.

The Analysis of Septic Tank Performance in Regard to Suspended Solids and Organic Matter Removal

Directory of Open Access Journals (Sweden)

Ala Kirjanova

2011-12-01

Full Text Available Abstract 117 The aim of this work was to evaluate the removal of suspended solids (SS and 7-day biochemical oxygen demand (BOD7 in a three chamber septic tank depending on theoretical wastewater retention time and the degree of septic tank cleanliness. It was found out that the performance of the septic tank depended on the degree of its cleanliness: when the septic tank was clean and retention time was three days, SS and BOS7 removal efficiency was 77±10% and 67±14% respectively, whereas two months later, after septic tank desludging, SS removal efficiency decreased to 53±22% and BOD7 to 32±31%. The performance of the septic tank also depended on theoretical wastewater retention time: when some amount of solids was accumulated at the bottom of the septic tank and wastewater retention time was one day, SS and BOS7 removal efficiency was 45±40% and 33±16% respectively; when retention time was three days, SS removal efficiency increased to 53±22% but BOD7 removal efficiency remained similar to one day retention time, i.e. 32±31%.Article in Lithuanian

Effectiveness of foam-based and traditional green roofs in reducing nitrogen, phosphorus, organic carbon and suspended solids in urban installations

Science.gov (United States)

MacAvoy, S. E.; Mucha, S.; Williamson, G.

2017-12-01

While green roofs have well understood benefits for retaining runoff, there is less of a consensus regarding the potential for retaining and absorbing nutrients or suspended solids from roof runoff that would otherwise travel to waterways. Additionally, there are numerous designs, materials and maintenance plans associated with "green" roofs/surfaces that may greatly impact not only their hydrological benefit but also their pollution mitigation potential. Here we examine the NO3, NH4, total organic carbon (TOC), total phosphorus (TP) and total suspended solids (TSS) retention potential from planted and unplanted foam roofs and traditional soil roofs. Direct precipitation, untreated runoff and throughflow from the different roof types were collected for 3 to 11 rain events over a year (depending on roof). Unplanted and traditional roofs reduced TSS by 80% or better relative to runoff. Traditional roofs showed 50% lower TP than runoff or other roof types. TOC was higher than direct precipitation for all treatments, although there were no differences among the treatments themselves. Taken as averages over the 11 events, NO3 and NH4 concentrations were highly variable for runoff and treatments and significant differences were not detected. Preliminary analysis suggests there were no differences between performance of traditional versus foam-based roofs, although a greater sample size is required to be definitive.

Loads of nitrate, phosphorus, and total suspended solids from Indiana watersheds

Science.gov (United States)

Bunch, Aubrey R.

2016-01-01

Transport of excess nutrients and total suspended solids (TSS) such as sediment by freshwater systems has led to degradation of aquatic ecosystems around the world. Nutrient and TSS loads from Midwestern states to the Mississippi River are a major contributor to the Gulf of Mexico Hypoxic Zone, an area of very low dissolved oxygen concentration in the Gulf of Mexico. To better understand Indiana’s contribution of nutrients and TSS to the Mississippi River, annual loads of nitrate plus nitrite as nitrogen, total phosphorus, and TSS were calculated for nine selected watersheds in Indiana using the load estimation model, S-LOADEST. Discrete water-quality samples collected monthly by the Indiana Department of Environmental Management’s Fixed Stations Monitoring Program from 2000–2010 and concurrent discharge data from the U. S. Geological Survey streamflow gages were used to create load models. Annual nutrient and TSS loads varied across Indiana by watershed and hydrologic condition. Understanding the loads from large river sites in Indiana is important for assessing contributions of nutrients and TSS to the Mississippi River Basin and in determining the effectiveness of best management practices in the state. Additionally, evaluation of loads from smaller upstream watersheds is important to characterize improvements at the local level and to identify priorities for reduction.

Treatment and remediation of a wastewater lagoon using microelectrolysis and modified DAT/IAT methods.

Science.gov (United States)

Wu, Qiong; Hua, Tao; Zhou, Qixing

2011-01-01

To examine treatment and remediation of a wastewater lagoon with poor biodegradability, a typical wastewater lagoon in Tianjin, China, was treated and remedied using microelectrolysis and modified demand aeration tank (DAT)/intermittent aeration tank (IAT) methods. After pretreatment by microelectrolysis, the removal efficiency of chemical oxygen demand (COD) was up to 64.6% and the ratio of BOC/COD in the effluent increased from 0.013 to 0.609. The removal rates of COD(Cr) and NH4(+)-N were affected by sludge backflow rate, mixed liquor suspended solids (MLSS), and hydraulic retention time (HRT) in the modified DAT/IAT reactor. The highest removal rates of COD(Cr) and NH4(+)-N were up to 78.9% and 62.6%, respectively, when the sludge backflow rate was 38.0 mL/min, the total HRT was 8.0 hr and MLSS was 4088.0 mg/L. In this case, some protozoa and metazoa were observed in activated sludge and biofilm carriers. Most of chrominance was removed by microelectrolysis treatment, while the modified DAT/IAT methods were more effective for COD(Cr) and NH4(+)-N removal.

Modeling Trace Element Concentrations in the San Francisco Bay Estuary from Remote Measurement of Suspended Solids

Science.gov (United States)

Press, J.; Broughton, J.; Kudela, R. M.

2014-12-01

Suspended and dissolved trace elements are key determinants of water quality in estuarine and coastal waters. High concentrations of trace element pollutants in the San Francisco Bay estuary necessitate consistent and thorough monitoring to mitigate adverse effects on biological systems and the contamination of water and food resources. Although existing monitoring programs collect annual in situ samples from fixed locations, models proposed by Benoit, Kudela, & Flegal (2010) enable calculation of the water column total concentration (WCT) and the water column dissolved concentration (WCD) of 14 trace elements in the San Francisco Bay from a more frequently sampled metric—suspended solids concentration (SSC). This study tests the application of these models with SSC calculated from remote sensing data, with the aim of validating a tool for continuous synoptic monitoring of trace elements in the San Francisco Bay. Using HICO imagery, semi-analytical and empirical SSC algorithms were tested against a USGS dataset. A single-band method with statistically significant linear fit (p Arsenic, Iron, and Lead in the southern region of the Bay were found to exceed EPA water quality criteria for human health and aquatic life. The results of this study demonstrate the potential of monitoring programs using remote observation of trace element concentrations, and provide the foundation for investigation of pollutant sources and pathways over time.

Suspending Zeolite Particles In Tanks

International Nuclear Information System (INIS)

Poirier, M.R.

1999-01-01

The Savannah River Site (SRS) is in the process of removing waste (sludge and salt cake) from million gallon waste tanks. The current practice for removing waste from the tanks is adding water, agitating the tanks with long shaft vertical centrifugal pumps, and pumping the sludge/salt solution from the tank to downstream treatment processes. This practice has left sludge heels (tilde 30,000 gallons) in the bottom of the tanks. SRS is evaluating shrouded axial impeller mixers for removing the sludge heels in the waste tanks. The authors conducted a test program to determine mixer requirements for suspending sludge heels using the shrouded axial impeller mixers. The tests were performed with zeolite in scaled tanks which have diameters of 1.5, 6.0, and 18.75 feet. The mixer speeds required to suspend zeolite particles were measured at each scale. The data were analyzed with various scaling methods to compare their ability to describe the suspension of insoluble solids with the mixers and to apply the data to a full-scale waste tank. The impact of changes in particle properties and operating parameters was also evaluated. The conclusions of the work are: Scaling of the suspension of fast settling zeolite particles was best described by the constant power per unit volume method. Increasing the zeolite particle concentration increased the required mixer power needed to suspend the particles. Decreasing the zeolite particle size from 0.7 mm 0.3 mm decreased the required mixer power needed to suspend the particles. Increasing the number of mixers in the tank decreased the required mixer power needed to suspend the particles. A velocity of 1.6 ft/sec two inches above the tank bottom is needed to suspend zeolite particles

Removal of total suspended solid by natural coagulant derived from cassava peel waste

Science.gov (United States)

Mohd-Asharuddin, S.; Othman, N.; Mohd-Zin, N. S.; Tajarudin, H. A.

2018-04-01

The present study was aimed to investigate the performance of starch derived from cassava peel waste as primary coagulant and coagulant aid. Comparable study was also conducted using commercially used aluminium sulfate (alum) as primary coagulant. A series of Jar tests were performed using raw water from Sembrong Barat water treatment plant. It was observed that coagulation test using cassava peel starch (CPS) alone had unappreciable removing ability. However, it was found that combination of alum-CPS successfully achieve up to 90.48% of total suspended solid (TSS) removal under optimized working conditions (pH 9, 7.5mg/L : 100 mg/L of alum : CPS dosage, rapid mixing of 200 rpm for 1 minute; 100 rpm for 2 minutes, slow mixing of 25 rpm for 30 minutes and 30 minutes settling time). This remarks the reduction in alum dosage up to 50% compared to coagulation test using alum alone. Therefore this finding suggesting that CPS can be considered as potential source of sustainable and effective coagulant aid for water treatment especially in developing countries.

Characteristic of total suspended particulate (TSP) containing Pb and Zn at solid waste landfill

Science.gov (United States)

Budihardjo, M. A.; Noveandra, K.; Samadikun, B. P.

2018-05-01

Activities conducted at municipal solid waste landfills (MSWLs) potentially cause air pollution. Heavy vehicles in MSWLs release various pollutants that can have negative impacts for humans. One noticeable pollutant at MSWLs is airborne total suspended particulate (TSP) which may contain heavy metals such as Pb and Zn and can cause disease when inhaled by humans. In this study, TSP from a landfill in Semarang, Indonesia was collected and characterized to quantify the concentration of Pb and Zn. Meteorological factors (i.e. temperature, humidity and wind velocity) and landfill activities were considered as factors affecting pollutant concentrations. TSP was sampled using dust samplers while the concentrations of heavy metals in TSP were analyzed using an Atomic Absorption Spectrophotometer (AAS). Pb concentration ranged from 0.84 to 1.78 µg/m3 while Zn concentration was from 7.87 to 8.76 µg/m3. The levels of Pb were below the threshold specified by the Indonesian Government. Meanwhile, the threshold for Zn has not yet been determined.

Bio-diatomite dynamic membrane reactor for micro-polluted surface water treatment.

Science.gov (United States)

Chu, Huaqiang; Cao, Dawen; Dong, Bingzhi; Qiang, Zhimin

2010-03-01

This work investigated the feasibility of treating micro-polluted surface water for drinking water production with a bio-diatomite dynamic membrane reactor (BDDMR) at lab-scale in continuous-flow mode. Results indicate that the BDDMR was effective in removing COD(Mn), DOC, UV(254), NH(3)-N and trihalomethanes' formation potential (THMFP) at a hydraulic retention time (HRT) of 3.5h due to its high concentrations of mixed liquor suspended solids (MLSS) and mixed liquor volatile suspended solids (MLVSS). The removal of pollutants was mainly ascribed to microbial degradation in BDDMR because the dynamic membrane alone was much less effective in pollutant removal. Though the diatomite particles (5-20microm) were much smaller in size than the aperture of the stainless steel support mesh (74microm), microorganisms and their extracellular polymer substances could bind these particles tightly to form bio-diatomite particles which were completely retained by the support mesh. The analysis of molecular weight (MW) distribution by gel permeation chromatography (GPC) shows that the BDDMR could effectively remove the hydrophilic fraction of dissolved organic materials present in the raw water. Copyright 2009 Elsevier Ltd. All rights reserved.

Assessment of suspended solids concentration in highway runoff and its treatment implication.

Science.gov (United States)

Hallberg, M; Renman, G

2006-09-01

It is understood that the major pollution from storm water is related to the content of particulate matter. One treatment practice is based on the first flush, i.e. detention of the initial part of the runoff that is considered to contain the highest concentrations of pollutants. This study has evaluated the concentration of total suspended solids in 30 consecutive runoff events during the winter season for an area of 6.7 hectares. A six-lane highway (E4) that has an annual average daily traffic load of 120,000 dominates the area and road de-icing salt (NaCl) and studded tires were in regular use during the studied period. The effluent standard for wastewater of 60 mg TSS per litre applied in EU was used to assess the treatment requirement of storm water. In only two of the events the event mean concentration was below 60 mg 1(-1). In four runoff events a partial event mean concentration below 60 mg 1(-1) was found, in 26 %, 12 %, 11 %, and 2 % respectively of the runoff volume. This would suggest that a capture of the initial part of the runoff for subsequent treatment is less applicable in this type of urban watershed.

Assessments of lake profiling on temperature, Total Suspended ...

African Journals Online (AJOL)

Interpolation were performed on temperature, total suspended solid (TSS) and turbidity (TUR) based on in-situ and ex-situ analyses according to the correlation matrix and linear regression at 14 different depths for the Chomor River and Mahadir Island. The result showed outlet significantly decreased over depth caused the ...

Metal extraction by solid-liquid agglomerates

International Nuclear Information System (INIS)

Fuller, E.F.

1980-01-01

Dissolved metal values are extracted from a liquid e.g. uranium from phosphoric acid by contacting the liquid with agglomerates for a time to load the agglomerate with the metal value, separating the loaded agglomerates from the liquid phase and stripping the metal value from the loaded agglomerate. The agglomerate may be made by combining finely divided solid particles with a binding liquid to form a paste, adding a suspending liquid to form a mixture, the suspending liquid and binding liquid being immiscible in each other and the solid particles being insoluble in the suspending liquid and shearing the mixture to form the agglomerate. (author)

Self-Suspended Suspensions of Covalently Grafted Hairy Nanoparticles

KAUST Repository

Choudhury, Snehashis

2015-03-17

© 2015 American Chemical Society. Dispersions of small particles in liquids have been studied continuously for almost two centuries for their ability to simultaneously advance understanding of physical properties of fluids and their widespread use in applications. In both settings, the suspending (liquid) and suspended (solid) phases are normally distinct and uncoupled on long length and time scales. In this study, we report on the synthesis and physical properties of a novel family of covalently grafted nanoparticles that exist as self-suspended suspensions with high particle loadings. In such suspensions, we find that the grafted polymer chains exhibit unusual multiscale structural transitions and enhanced conformational stability on subnanometer and nanometer length scales. On mesoscopic length scales, the suspensions display exceptional homogeneity and colloidal stability. We attribute this feature to steric repulsions between grafted chains and the space-filling constraint on the tethered chains in the single-component self-suspended materials, which inhibits phase segregation. On macroscopic length scales, the suspensions exist as neat fluids that exhibit soft glassy rheology and, counterintuitively, enhanced elasticity with increasing temperature. This feature is discussed in terms of increased interpenetration of the grafted chains and jamming of the nanoparticles. (Chemical Presented).

Filterability of membrane bioreactor (MBR) sludge: impacts of polyelectrolytes and mixing with conventional activated sludge.

Science.gov (United States)

Yigit, Nevzat O; Civelekoglu, Gokhan; Cinar, Ozer; Kitis, Mehmet

2010-01-01

The main objective of this work was to investigate the filterability of MBR sludge and its mixture with conventional activated sludge (CAS). In addition, the impacts of type and dose of various polyelectrolytes, filter type and sludge properties on the filterability of both MBR and Mixed sludges were determined. Specific cake resistance (SCR) measured by the Buchner funnel filtration test apparatus and the solids content of the resulting sludge cake were used to assess the dewaterability of tested sludges. The type of filter paper used in Buchner tests affected the results of filterability for MBR, CAS and Mixed sludges. SCR values and optimum polyelectrolyte doses increased with increasing MLSS concentrations in the MBR, which suggested that increase in MLSS concentrations accompanied by increases in EPS and SMP concentrations and a shift toward smaller particles caused poorer dewaterability of the MBR sludge. The significant differences observed among the filterability of CAS and MBR sludges suggested that MLSS alone is not a good predictor of sludge dewaterability. Combining CAS and MBR sludges at different proportions generally improved their dewaterability. Combining MBR sludges having typically high MLSS and EPS concentrations with CAS having much lower MLSS concentrations may be an option for full-scale treatment plants experiencing sludge dewaterability problems. Better filterability and higher cake dry solids were achieved with cationic polyelectrolytes compared to anionic and non-ionic ones for all sludge types tested.

Flywheel Energy Storage System Suspended by Hybrid Magnetic Bearing

Science.gov (United States)

Owusu-Ansah, Prince; Hu, Yefa; Misbawu, Adam

This work presents a prototype flywheel energy storage system (FESS) suspended by hybrid magnetic bearing (HMB) rotating at a speed of 20000rpm with a maximum storage power capacity of 30W with a maximum tip speed of 300m/s. The design presented is an improvement of most existing FESS, as the design incorporates a unique feature in that the upper and the lower rotor and stator core are tapered which enhances larger thrust and much lower radial force to be exerted on the system. Without any adverse effect being experienced by the model. The work also focuses on the description of developing a prototype FESS suspended by HMB using solid works as a basis of developing in the nearer future a more improved FESS suspended by HMB capable of injecting the ever increasing high energy demand situation in the 21st century and beyond.

A submerged tubular ceramic membrane bioreactor for high strength wastewater treatment.

Science.gov (United States)

Sun, D D; Zeng, J L; Tay, J H

2003-01-01

A 4 L submerged tubular ceramic membrane bioreactor (MBR) was applied in laboratory scale to treat 2,400 mg-COD/L high strength wastewater. A prolonged sludge retention time (SRT) of 200 day, in contrast to the conventional SRT of 5 to 15 days, was explored in this study, aiming to reduce substantially the amount of disposed sludge. The MBR system was operated for a period of 142 days in four runs, differentiated by specific oxygen utilization rate (SOUR) and hydraulic retention time (HRT). It was found that the MBR system produced more than 99% of suspended solid reduction. Mixed liquor suspended solids (MLSS) was found to be adversely proportional to HRT, and in general higher than the value from a conventional wastewater treatment plant. A chemical oxygen demand (COD) removal efficiency was achieved as high as 98% in Run 1, when SOUR was in the range of 100-200 mg-O/g-MLVSS/hr. Unexpectedly, the COD removal efficiency in Run 2 to 4 was higher than 92%, on average, where higher HRT and abnormally low SOUR of 20-30 mg-O/g-MLVSS/hr prevailed. It was noted that the ceramic membrane presented a significant soluble nutrient rejection when the microbial metabolism of biological treatment broke down.

Anaerobic treatment of wastewater with high suspended solids from a bulk drug industry using fixed film reactor (AFFR).

Science.gov (United States)

Gangagni Rao, A; Venkata Naidu, G; Krishna Prasad, K; Chandrasekhar Rao, N; Venkata Mohan, S; Jetty, Annapurna; Sarma, P N

2005-01-01

Studies were carried out on the treatment of wastewater from a bulk drug industry using an anaerobic fixed film reactor (AFFR) designed and fabricated in the laboratory. The chemical oxygen demand (COD) and total dissolved solids (TDS) of the wastewater were found to be very high with low biochemical oxygen demand (BOD) to COD ratio and high total suspended solid (TSS) concentration. Acclimatization of seed consortia and startup of the reactor was carried out by directly using the wastewater, which resulted in reducing the period of startup to 30 days. The reactor was studied at different organic loading rates (OLR) and it was found that the optimum OLR was 10 kg COD/m(3)/day. The wastewater under investigation, which had a considerable quantity of SS, was treated anaerobically without any pretreatment. COD and BOD of the reactor outlet wastewater were monitored and at steady state and optimum OLR 60-70% of COD and 80-90% of BOD were removed. The reactor was subjected to organic shock loads at two different OLR and the reaction could withstand the shocks and performance could be restored to normalcy at that OLR. The results obtained indicated that AFFR could be used efficiently for the treatment of wastewater from a bulk drug industry having high COD, TDS and TSS.

Coincident patterns of waste water suspended solids reduction, water transparency increase and chlorophyll decline in Narragansett Bay.

Science.gov (United States)

Borkman, David G; Smayda, Theodore J

2016-06-15

Dramatic changes occurred in Narragansett Bay during the 1980s: water clarity increased, while phytoplankton abundance and chlorophyll concentration decreased. We examine how changes in total suspended solids (TSS) loading from wastewater treatment plants may have influenced this decline in phytoplankton chlorophyll. TSS loading, light and phytoplankton observations were compiled and a light- and temperature-dependent Skeletonema-based phytoplankton growth model was applied to evaluate chlorophyll supported by TSS nitrogen during 1983-1995. TSS loading declined 75% from ~0.60×10(6)kgmonth(-1) to ~0.15×10(6)kgmonth(-1) during 1983-1995. Model results indicate that nitrogen reduction related to TSS reduction was minor and explained a small fraction (~15%) of the long-term chlorophyll decline. The decline in NBay TSS loading appears to have increased water clarity and in situ irradiance and contributed to the long-term chlorophyll decline by inducing a physiological response of a ~20% reduction in chlorophyll per cell. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nickel toxicity to benthic organisms: The role of dissolved organic carbon, suspended solids, and route of exposure.

Science.gov (United States)

Custer, Kevin W; Hammerschmidt, Chad R; Burton, G Allen

2016-01-01

Nickel bioavailability is reduced in the presence of dissolved organic carbon (DOC), suspended solids (TSS), and other complexing ligands; however, no studies have examined the relative importance of Ni exposure through different compartments (water, sediment, food). Hyalella azteca and Lymnaea stagnalis were exposed to Ni-amended water, sediment, and food, either separately or in combination. Both organisms experienced survival and growth effects in several Ni compartment tests. The DOC amendments attenuated L. stagnalis Ni effects (survival, growth, and (62)Ni bioaccumulation), and presence of TSS exposures demonstrated both protective and synergistic effects on H. azteca and L. stagnalis. (62)Ni trophic transfer from food to H. azteca and L. stagnalis was negligible; however, bioaccumulating (62)Ni was attributed to (62)Ni-water ((62)Ni flux from food), (62)Ni-TSS, and (62)Ni-food. Overall, H. azteca and L. stagnalis Ni compartment toxicity increased in the following order: Ni-water > Ni-sediment > Ni-all (water, sediment, food) > Ni-food. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nitrogen and phosphorus associating with different size suspended solids in roof and road runoff in Beijing, China.

Science.gov (United States)

Wu, Junliang; Ren, Yufen; Wang, Xuemei; Wang, Xiaoke; Chen, Liding; Liu, Gangcai

2015-10-01

Roofs and roads, accounting for a large portion of the urban impervious land surface, have contributed significantly to urban nonpoint pollution. In this study, in Beijing, China, roof and road runoff are sampled to measure the suspended solids (SS), nitrogen (N), and phosphorus (P) contained in particles with different sizes. The SS content in the road runoff (151.59 mg/L) was sevenfold that in the roof runoff (21.13 mg/L, p runoff than in road runoff. The small particulates in the range of 0.45-50 μm consisted of 59 % SS in the roof runoff and 94 % SS in the road runoff. P was mainly attached to particle sizes of 10-50 μm in the roof (73 %) and road (48 %) runoffs, while N was mainly in a dissolved phase state in both runoffs. So, the different associations of N and P raise a challenge in preventing stormwater pollution in urban environments.

Numerical simulation of the motion of charged suspended particle in multi-phase flow

Energy Technology Data Exchange (ETDEWEB)

Abd Elkhalek, M M [Nuclear Research Center-Atomic Energy Authority, Cairo (Egypt)

1997-12-31

A method for computing numerical simulation of the motion of charged suspended particle in multi-phase flow between two-long parallel plates is described in detail. The equation of motion of a suspended particle was suggested by closkin. The equations of motion are reduced to ordinary differential equations by similarity transformations and solved numerically by using Runge-Kutta method. The trajectories of particles are calculated by integrating the equation of motion of a single particle. Numerical solutions of the resulting ordinary differential equations provide velocity distributions for both fluid and solid phases and density distributions for the solid. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically. 4 figs.

Numerical Simulation of the Motion of Charged Suspended Particle in Multi-Phase Flow

International Nuclear Information System (INIS)

Abd-El Khalek, M.M.

1998-01-01

A method for computing Numerical simulation of the motion of charged suspended particle in multi-phase flow between two-long parallel plates is described in detail. The equation of motion of a suspended particle was suggested by Closkin. The equations of motion are reduced to ordinary differential equations by similarity transformations and solved numerically by using the Runge-Kutta method. The trajectories of particles are calculated by integrating the equation of motion of a single particle. Numerical solutions of the resulting ordinary differential equations provide velocity distributions for both fluid and solid phases and density distributions for the solid. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically

Implementation of CFD modeling in the performance assessment and optimization of secondary clarifiers: the PVSC case study.

Science.gov (United States)

Xanthos, S; Ramalingam, K; Lipke, S; McKenna, B; Fillos, J

2013-01-01

The water industry and especially the wastewater treatment sector has come under steadily increasing pressure to optimize their existing and new facilities to meet their discharge limits and reduce overall cost. Gravity separation of solids, producing clarified overflow and thickened solids underflow has long been one of the principal separation processes used in treating secondary effluent. Final settling tanks (FSTs) are a central link in the treatment process and often times act as the limiting step to the maximum solids handling capacity when high throughput requirements need to be met. The Passaic Valley Sewerage Commission (PVSC) is interested in using a computational fluid dynamics (CFD) modeling approach to explore any further FST retrofit alternatives to sustain significantly higher plant influent flows, especially under wet weather conditions. In detail there is an interest in modifying and/or upgrading/optimizing the existing FSTs to handle flows in the range of 280-720 million gallons per day (MGD) (12.25-31.55 m(3)/s) in compliance with the plant's effluent discharge limits for total suspended solids (TSS). The CFD model development for this specific plant will be discussed, 2D and 3D simulation results will be presented and initial results of a sensitivity study between two FST effluent weir structure designs will be reviewed at a flow of 550 MGD (∼24 m(3)/s) and 1,800 mg/L MLSS (mixed liquor suspended solids). The latter will provide useful information in determining whether the existing retrofit of one of the FSTs would enable compliance under wet weather conditions and warrants further consideration for implementing it in the remaining FSTs.

RECENT DYNAMICS (1975 - 2012 OF COŞUŞTEA RIVER'S SUSPENDED SEDIMENT LOAD AT CORCOVA HYDROMETRIC STATION

Directory of Open Access Journals (Sweden)

Gabriela Adina MOROȘANU

2016-03-01

Full Text Available This paper aims to assess, from a statistical standpoint, the solid discharge at Corcova hydrometric station for the recent period between 1975 and 2012. The Corcova hydrometric station is located in the lowermost sector of the Coşuştea River Basin, at a distance of 2 km north-west from its confluence with Motru River. The usefulness of this study results from the endeavor to determine the years and months when the river presents an accumulation potential due to a higher transmission rate of the suspended sediment load. The statistical techniques applied in this study made use of the monthly, as well as the annual averages, minimum and maximum values of suspended sediment loads, in order to obtain the multiannual trends, seasonal and monthly differences. Thus, by using the Mann-Kendall test, the statistical distributions and frequency analysis, we could notice that the average solid discharge decreased in the last decades during the winter period, while between April and November, average solid discharge rose slightly, with a greater significance in May. Conversely, minimum solid discharge values were likely to indicate the years and months when the river’s solid intake was low, with the potential for bank erosion. The minimum values of suspended sediment loads showed little variation from year to year in all months, except for May and June, based on the influence of the peak liquid discharge on the potential erosion and sediment transport of Cosustea river. As a general conclusion, the most important aspects turned out to be the variations in April - June period, an interval well known for flash floods and high waters records, as well as for rapid changes in average, minimum and maximum solid flows.

Predicting runoff of suspended solids and particulate phosphorus for selected Louisiana soils using simple soil tests.

Science.gov (United States)

Udeigwe, Theophilus K; Wang, Jim J; Zhang, Hailin

2007-01-01

This study was conducted to evaluate the relationships among total suspended solids (TSS) and particulate phosphorus (PP) in runoff and selected soil properties. Nine Louisiana soils were subjected to simulated rainfall events, and runoff collected and analyzed for various parameters. A highly significant relationship existed between runoff TSS and runoff turbidity. Both runoff TSS and turbidity were also significantly related to runoff PP, which on average accounted for more than 98% of total P (TP) in the runoff. Runoff TSS was closely and positively related to soil clay content in an exponential fashion (y=0.10e0.01x, R2=0.91, Psoil electrical conductivity (EC) (y=0.02 x(-3.95), R2=0.70, Psoil suspension turbidity" (SST) which measures turbidity in a 1:200 soil/water suspension, exhibited highly significant linear relationships with runoff TSS (y=0.06x-4.38, R2=0.82, Psoil clay content and EC in a multiple regression, suggesting that SST was able to account for the integrated effect of clay content and electrolytic background on runoff TSS. The SST test could be used for assessment and management of sediment and particulate nutrient losses in surface runoff.

Treatment of suspended solids and heavy metals from urban stormwater runoff by a tree box filter.

Science.gov (United States)

Geronimo, F K F; Maniquiz-Redillas, M C; Tobio, J A S; Kim, L H

2014-01-01

Particulates, inorganic and toxic constituents are the most common pollutants associated with urban stormwater runoff. Heavy metals such as chromium, nickel, copper, zinc, cadmium and lead are found to be in high concentration on paved roads or parking lots due to vehicle emissions. In order to control the rapid increase of pollutant loads in stormwater runoff, the Korean Ministry of Environment proposed the utilization of low impact developments. One of these was the application of tree box filters that act as a bioretention treatment system which executes filtration and sorption processes. In this study, a tree box filter located adjacent to an impervious parking lot was developed to treat suspended solids and heavy metal concentrations from urban stormwater runoff. In total, 11 storm events were monitored from July 2010 to August 2012. The results showed that the tree box filter was highly effective in removing particulates (up to 95%) and heavy metals (at least 70%) from the urban stormwater runoff. Furthermore, the tree box filter was capable of reducing the volume runoff by 40% at a hydraulic loading rate of 1 m/day and below.

Treatment of domestic wastewater with an anaerobic ceramic membrane bioreactor (AnCMBR).

Science.gov (United States)

Yue, Xiaodi; Koh, Yoong Keat Kelvin; Ng, How Yong

2015-01-01

In this study, a ceramic membrane with a pore size of 80 nm was incorporated into an anaerobic membrane bioreactor for excellent stability and integrity. Chemical oxygen demand (COD) removal efficiencies by biodegradation reached 78.6 ± 6.0% with mixed liquor suspended solids (MLSS) of 12.8 ± 1.2 g/L. Even though the total methane generated was 0.3 ± 0.03 L/g CODutilized, around 67.4% of it dissolved in permeate and was lost beyond collection. As a result, dissolved methane was 2.7 times of the theoretical saturating concentration calculated from Henry's law. When transmembrane pressure (TMP) of the ceramic membrane reached 30 kPa after 25.3 d, 95.2% of the total resistance was attributed to the cake layer, which made it the major contributor to membrane fouling. Compared to the mixed liquor, cake layer was rich in colloids and soluble products that could bind the solids to form a dense cake layer. The Methanosarcinaceae family preferred to attach to the ceramic membranes.

Critical modeling parameters identified for 3D CFD modeling of rectangular final settling tanks for New York City wastewater treatment plants.

Science.gov (United States)

Ramalingam, K; Xanthos, S; Gong, M; Fillos, J; Beckmann, K; Deur, A; McCorquodale, J A

2012-01-01

New York City Environmental Protection is in the process of incorporating biological nitrogen removal (BNR) in its wastewater treatment plants (WWTPs) which entails operating the aeration tanks with higher levels of mixed liquor suspended solids (MLSS) than a conventional activated sludge process. The objective of this paper is to discuss two of the important parameters introduced in the 3D CFD model that has been developed by the City College of New York (CCNY) group: (a) the development of the 'discrete particle' measurement technique to carry out the fractionation of the solids in the final settling tank (FST) which has critical implications in the prediction of the effluent quality; and (b) the modification of the floc aggregation (K(A)) and floc break-up (K(B)) coefficients that are found in Parker's flocculation equation (Parker et al. 1970, 1971) used in the CFD model. The dependence of these parameters on the predictions of the CFD model will be illustrated with simulation results on one of the FSTs at the 26th Ward WWTP in Brooklyn, NY.

Hydrology, phosphorus, and suspended solids in five agricultural streams in the Lower Fox River and Green Bay Watersheds, Wisconsin, Water Years 2004-06

Science.gov (United States)

Graczyk, David J.; Robertson, Dale M.; Baumgart, Paul D.; Fermanich, Kevin J.

2011-01-01

A 3-year study was conducted by the U.S. Geological Survey and the University of Wisconsin-Green Bay to characterize water quality in agricultural streams in the Fox/Wolf watershed in northeastern Wisconsin and provide information to assist in the calibration of a watershed model for the area. Streamflow, phosphorus, and suspended solids data were collected between October 1, 2003, and September 30, 2006, in five streams, including Apple Creek, Ashwaubenon Creek, Baird Creek, Duck Creek, and the East River. During this study, total annual precipitation was close to the 30-year normal of 29.12 inches. The 3-year mean streamflow was highest in the East River (113 ft3/s), followed by Duck Creek (58.2 ft3/s), Apple Creek (26.9 ft3/s), Baird Creek (12.8 ft3/s), and Ashwaubenon Creek (9.1 ft3/s). On a yield basis, during these three years, the East River had the highest flow (0.78 ft3/s/mi2), followed by Baird Creek (0.61 ft3/s/mi2), Apple Creek (0.59 ft3/s/mi2), Duck Creek (0.54 ft3/s/mi2), and Ashwaubenon Creek (0.46 ft3/s/mi2). The overall median total suspended solids (TSS) concentration was highest in Baird Creek (73.5 mg/L), followed by Apple and Ashwaubenon Creeks (65 mg/L), East River (40 mg/L), and Duck Creek (30 mg/L). The median total phosphorus (TP) concentration was highest in Ashwaubenon Creek (0.60 mg/L), followed by Baird Creek (0.47 mg/L), Apple Creek (0.37 mg/L), East River (0.26 mg/L), and Duck Creek (0.22 mg/L).

Use of acoustic backscatter and vertical velocity to estimate concentration and dynamics of suspended solids in Upper Klamath Lake, south-central Oregon: Implications for Aphanizomenon flos-aquae

Science.gov (United States)

Wood, Tamara M.; Gartner, Jeffrey W.

2010-01-01

Vertical velocity and acoustic backscatter measurements by acoustic Doppler current profilers were used to determine seasonal, subseasonal (days to weeks), and diel variation in suspended solids in a freshwater lake where massive cyanobacterial blooms occur annually. During the growing season, the suspended material in the lake is dominated by the buoyancy-regulating cyanobacteria, Aphanizomenon flos-aquae. Measured variables (water velocity, relative backscatter [RB], wind speed, and air and water temperatures) were averaged over the deployment season at each sample time of day to determine average diel cycles. Phase shifts between diel cycles in RB and diel cycles in wind speed, vertical water temperature differences (delta T(degree)), and horizontal current speeds were found by determining the lead or lag that maximized the linear correlation between the respective diel cycles. Diel cycles in RB were more in phase with delta T(degree) cycles, and, to a lesser extent, wind cycles, than to water current cycles but were out of phase with the cycle that would be expected if the vertical movement of buoyant cyanobacteria colonies was controlled primarily by light. Clear evidence of a diel cycle in vertical velocity was found only at the two deepest sites in the lake. Cycles of vertical velocity, where present, were out of phase with expected vertical motion of cyanobacterial colonies based on the theoretical cycle for light-driven vertical movement. This suggests that water column stability and turbulence were more important factors in controlling vertical distribution of colonies than light. Variations at subseasonal time scales were determined by filtering data to pass periods between 1.2 and 15 days. At subseasonal time scales, correlations between RB and currents or air temperature were consistent with increased concentration of cyanobacterial colonies near the surface when water column stability increased (higher air temperatures or weaker currents) and

Trace organics removal using three membrane bioreactor configurations: MBR, IFAS-MBR and MBMBR.

Science.gov (United States)

de la Torre, T; Alonso, E; Santos, J L; Rodríguez, C; Gómez, M A; Malfeito, J J

2015-01-01

Seventeen pharmaceutically active compounds and 22 other trace organic pollutants were analysed regularly in the influent and permeate from a semi-real plant treating municipal wastewater. The plant was operated during 29 months with different configurations which basically differed in the type of biomass present in the system. These processes were the integrated fixed-film activated sludge membrane bioreactor (IFAS-MBR), which combined suspended and attached biomass, the moving bed membrane bioreactor (MBMBR) (only attached biomass) and the MBR (only suspended biomass). Moreover, removal rates were compared to those of the wastewater treatment plant (WWTP) operating nearby with conventional activated sludge treatment. Reverse osmosis (RO) was used after the pilot plant to improve removal rates. The highest elimination was found for the IFAS-MBR, especially for hormones (100% removal); this was attributed to the presence of biofilm, which may lead to different conditions (aerobic-anoxic-anaerobic) along its profile, which increases the degradation possibilities, and also to a higher sludge age of the biofilm, which allows complete acclimation to the contaminants. Operating conditions played an important role, high mixed liquor suspended solids (MLSS) and sludge retention time (SRT) being necessary to achieve these high removal rates. Although pharmaceuticals and linear alkylbenzene sulfonates showed high removal rates (65-100%), nonylphenols and phthalate could only be removed to 10-30%. RO significantly increased removal rates to 88% mean removal rate.

Trends in nutrients and suspended solids at the Fall Line of five tributaries to the Chesapeake Bay in Virginia, July 1988 through June 1995

Science.gov (United States)

Bell, C.F.; Belval, D.L.; Campbell, J.P.

1996-01-01

Water-quality samples were collected at the Fall Line of five tributaries to the Chesapeake Bay in Virginia during a 6- to 7-year period. The water-quality data were used to estimate loads of nutrients and suspended solids from these tributaries to the non-tidal part of Chesapeake Bay Basin and to identify trends in water quality. Knowledge of trends in water quality is required to assess the effectiveness of nutrient manage- ment strategies in the five basins. Multivariate log-linear regression and the seasonal Kendall test were used to estimate flow-adjusted trends in constituent concentration and load. Results of multivariate log-linear regression indicated a greater number of statistically significant trends than the seasonal Kendall test; how-ever, when both methods indicated a significant trend, both agreed on the direction of the trend. Interpre- tation of the trend estimates for this report was based on results of the parametric regression method. No significant trends in total nitrogen concentration were detected at the James River monitoring station from July 1988 through June 1995, though total Kjeldahl nitrogen concen- tration decreased slightly in base-flow samples. Total phosphorus concentration decreased about 29 percent at this station during the sampling period. Most of the decrease can be attributed to reductions in point-source phosphorus loads in 1988 and 1989, especially the phosphate detergent ban of 1988. No significant trends in total suspended solids were observed at the James River monitoring station, and no trends in runoff- derived constituents were interpreted for this river. Significant decreases were detected in concentrations of total nitrogen, total Kjeldahl nitrogen, dissolved nitrite-plus-nitrate nitrogen, and total suspended solids at the Rappahannock River monitoring station between July 1988 and June 1995. A similar downward trend in total phosphorus concentration was significant at the 90-percent confidence level, but not the

Estuarine Suspended Sediment Dynamics: Observations Derived from over a Decade of Satellite Data

Directory of Open Access Journals (Sweden)

Anthony Reisinger

2017-12-01

Full Text Available Suspended sediment dynamics of Corpus Christi Bay, Texas, USA, a shallow-water wind-driven estuary, were investigated by combining field and satellite measurements of total suspended solids (TSS. An algorithm was developed to transform 500-m Moderate Resolution Imaging Spectroradiometer (MODIS Aqua satellite reflectance data into estimated TSS values. The algorithm was developed using a reflectance ratio regression of MODIS Band 1 (red and Band 3 (green with TSS measurements (n = 54 collected by the Texas Commission on Environmental Quality for Corpus Christi Bay and other Texas estuaries. The algorithm was validated by independently collected TSS measurements during the period of 2011–2014 with an uncertainty estimate of 13%. The algorithm was applied to the period of 2002–2014 to create a synoptic time series of TSS for Corpus Christi Bay. Potential drivers of long-term variability in suspended sediment were investigated. Median and IQR composites of suspended sediments were generated for seasonal wind regimes. From this analysis it was determined that long-term, spatial patterns of suspended sediment in the estuary are related to wind-wave resuspension during the predominant northerly and prevalent southeasterly seasonal wind regimes. The impact of dredging is also apparent in long-term patterns of Corpus Christi Bay as concentrations of suspended sediments over dredge spoil disposal sites are higher and more variable than surrounding areas, which is most likely due to their less consolidated sediments and shallower depths requiring less wave energy for sediment resuspension. This study highlights the advantage of how long-synoptic time series of TSS can be used to elucidate the major drivers of suspended sediments in estuaries.

Comparison of filtration and treatment performance between polymeric and ceramic membranes in anaerobic membrane bioreactor treatment of domestic wastewater

KAUST Repository

Jeong, Yeongmi

2018-02-28

The feasibility of an anaerobic ceramic membrane bioreactor (AnCMBR) was investigated by comparison with a conventional anaerobic membrane bioreactor (AnMBR). With regard to treatment performance, the AnCMBR achieved higher organic removal rates than the AnMBR because the ceramic membranes retained a high concentration of biomass in the reactor. Despite a high mixed liquor suspended solid (MLSS) concentration, the AnCMBR exhibited lower membrane fouling. To elucidate effects of sludge properties on membrane fouling in the AnCMBR and AnMBR, soluble microbial products (SMPs) and extracellular polymeric substances (EPSs) were analyzed. The SMP and EPS concentrations in the AnCMBR were higher than in the AnMBR. This may be because some suspended solids bio-degraded and likely released protein-like SMPs in the AnCMBR. Hydrophobicity and surface charges were analyzed; the sludge in the AnCMBR was found to be more hydrophobic and less negative than in the AnMBR because protein was abundant in the AnCMBR. Despite the adverse properties of the sludge in the AnCMBR, it showed more stable filtration performance than the AnMBR. This is because the alumina-based ceramic membrane had a superhydrophilic surface and could thus mitigate membrane fouling by hydrophilic-hydrophobic repulsion. The findings from this study have significant implications for extending the application of AnCMBRs to, for example, treatment of high-strength organic waste such as food waste or livestock manure.

Comparison of filtration and treatment performance between polymeric and ceramic membranes in anaerobic membrane bioreactor treatment of domestic wastewater

KAUST Repository

Jeong, Yeongmi; Kim, Youngjin; Jin, Yongxun; Hong, Seungkwan; Park, Chanhyuk

2018-01-01

The feasibility of an anaerobic ceramic membrane bioreactor (AnCMBR) was investigated by comparison with a conventional anaerobic membrane bioreactor (AnMBR). With regard to treatment performance, the AnCMBR achieved higher organic removal rates than the AnMBR because the ceramic membranes retained a high concentration of biomass in the reactor. Despite a high mixed liquor suspended solid (MLSS) concentration, the AnCMBR exhibited lower membrane fouling. To elucidate effects of sludge properties on membrane fouling in the AnCMBR and AnMBR, soluble microbial products (SMPs) and extracellular polymeric substances (EPSs) were analyzed. The SMP and EPS concentrations in the AnCMBR were higher than in the AnMBR. This may be because some suspended solids bio-degraded and likely released protein-like SMPs in the AnCMBR. Hydrophobicity and surface charges were analyzed; the sludge in the AnCMBR was found to be more hydrophobic and less negative than in the AnMBR because protein was abundant in the AnCMBR. Despite the adverse properties of the sludge in the AnCMBR, it showed more stable filtration performance than the AnMBR. This is because the alumina-based ceramic membrane had a superhydrophilic surface and could thus mitigate membrane fouling by hydrophilic-hydrophobic repulsion. The findings from this study have significant implications for extending the application of AnCMBRs to, for example, treatment of high-strength organic waste such as food waste or livestock manure.

Comparability of river suspended-sediment sampling and laboratory analysis methods

Science.gov (United States)

Groten, Joel T.; Johnson, Gregory D.

2018-03-06

Accurate measurements of suspended sediment, a leading water-quality impairment in many Minnesota rivers, are important for managing and protecting water resources; however, water-quality standards for suspended sediment in Minnesota are based on grab field sampling and total suspended solids (TSS) laboratory analysis methods that have underrepresented concentrations of suspended sediment in rivers compared to U.S. Geological Survey equal-width-increment or equal-discharge-increment (EWDI) field sampling and suspended sediment concentration (SSC) laboratory analysis methods. Because of this underrepresentation, the U.S. Geological Survey, in collaboration with the Minnesota Pollution Control Agency, collected concurrent grab and EWDI samples at eight sites to compare results obtained using different combinations of field sampling and laboratory analysis methods.Study results determined that grab field sampling and TSS laboratory analysis results were biased substantially low compared to EWDI sampling and SSC laboratory analysis results, respectively. Differences in both field sampling and laboratory analysis methods caused grab and TSS methods to be biased substantially low. The difference in laboratory analysis methods was slightly greater than field sampling methods.Sand-sized particles had a strong effect on the comparability of the field sampling and laboratory analysis methods. These results indicated that grab field sampling and TSS laboratory analysis methods fail to capture most of the sand being transported by the stream. The results indicate there is less of a difference among samples collected with grab field sampling and analyzed for TSS and concentration of fines in SSC. Even though differences are present, the presence of strong correlations between SSC and TSS concentrations provides the opportunity to develop site specific relations to address transport processes not captured by grab field sampling and TSS laboratory analysis methods.

Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals

DEFF Research Database (Denmark)

Falås, Per; Baillon-Dhumez, Aude; Andersen, Henrik Rasmus

2012-01-01

Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct...... and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast...

Development of equipment for migration control of radioactive cesium absorbed in suspended solid in the river water

International Nuclear Information System (INIS)

Ohyama, Takuya; Ishikawa, Hiroyasu

2015-01-01

To prevent inflow of radiocesium with suspended solids (SS) into farmland and increase in dose rate of the river bank in the midstream and downstream, it is important to reduce SS in the river water; therefore we newly developed the test equipment using non-woven fabrics as a trapping material to capture and reduce the SS in running small river water. Authors installed this equipment into the small river which is located in mountainous area surrounded by forests where radionuclides released from the Fukushima Daiichi Nuclear Power Plant were deposited. Two turbidity gauges are installed in inflow and outflow point of this equipment and the turbidity has been continuously measured. From the result of a comparison of turbidity between inflow point and outflow point, a turbidity of inflow point is always higher than outflow point during ordinary water-level; this equipment can capture and reduce the SS in the river water. Through the analysis of particle size distribution, identification of minerals and measurement of concentration of radioactive Cs of the captured SS in the non-woven fabric should be carried out, to clarify the effectiveness of this equipment and non-woven fabrics for reducing the radioactive Cs in small rivers in the future. (author)

Distribution and transportation of suspended sediment

International Nuclear Information System (INIS)

Schubel, J.R.

1975-01-01

A number of studies of the distribution and character of suspended matter in the waters of the Atlantic shelf have documented the variations in the concentration of total suspended matter in both time and space. Very little is known, however, about the ultimate sources of inorganic suspended matter, and even less is known about the routes and rates of suspended sediment transport in shelf waters. Suspended particulate matter constitutes a potential vehicle for the transfer of energy-associated contaminants, radionuclides and oil, back to the coast and therefore to man. The concentrations of total suspended matter in shelf waters are typically so low, however, that the mechanism is ineffective. Studies of suspended particulate matter have a high scientific priority, but in this investigator's opinion the state of knowledge is adequate for preparation of the environmental impact statements that would be required for siting of offshore nuclear power plants and for oil drilling on the Atlantic Continental Shelf

Remote Sensing and Water Quality Indicators in the West Flood Canal Semarang City: Spatio-temporal Structures of Lansat-8 Derived Chlorophyll-a and Total Suspended Solids

Science.gov (United States)

Subiyanto, Sawitri

2017-12-01

One of the waters that has been contaminated by industrial waste and domestic waste is the waters of West Flood Canal in Semarang City which is the estuary of the river system, which passes through the Western City of Semarang which is dense with residential and industrial. So, it is necessary to have information about the assessment of water quality in the estuary of the West Flood Canal. Remote sensing technology can analyze the results of recording the spectral characteristics of water with water quality parameters. One of the parameters for assessing water quality is Chlorophyll-a and Total Suspended Solid, can be estimated through remote sensing technology using multispectral Lansat-8 Satellite images data from April, June, and August, 2017 and there are three selected algorithms. Based on the results of TSS and Chlorophyll-A processing, the TSS shows values greater than or equal to 100 which can be said that West Flood Canal is damaged (hypertrophic). While the chlorophyll-a shows a value less than 100 indicating Eutrophic status (threatened). This is caused by the number of suspended materials in the water surface and also because of the disturbance of water vegetation in the form of weeds that destroy the function of the actual West Canal Flood.

Self-suspended permanent magnetic FePt ferrofluids

KAUST Repository

Dallas, Panagiotis

2013-10-01

We present the synthesis and characterization of a new class of self-suspended ferrofluids that exhibit remanent magnetization at room temperature. Our system relies on the chemisorption of a thiol-terminated ionic liquid with very low melting point on the surface of L10 FePt nanoparticles. In contrast, all types of ferrofluids previously reported employ either volatile solvents as the suspending media or superparamagnetic iron oxide nanoparticles (that lacks permanent magnetization) as the inorganic component. The ferrofluids do not show any sign of flocculation or phase separation, despite the strong interactions between the magnetic nanoparticles due to the strong chemisorption of the ionic liquid as evidenced by Raman spectroscopy and thermal analysis. Composites with high FePt loading (40 and 70. wt%) exhibit a pseudo solid-like rheological behavior and high remanent magnetization values (10.1 and 12.8. emu/g respectively). At lower FePt loading (12. wt%) a liquid like behavior is observed and the remanent and saturation magnetization values are 3.5 and 6.2. emu/g, respectively. The magnetic and flow properties of the materials can be easily fine tuned by controlling the type and amount of FePt nanoparticles used. © 2013 Elsevier Inc.

Karakteristik Total Padatan Tersuspensi (Total Suspended Solid Dan Kekeruhan (Turbidity Secara Vertikal Di Perairan Teluk Benoa, Bali

Directory of Open Access Journals (Sweden)

I Gede Hendrawan

2016-06-01

Full Text Available Benoa bay is one of estuary that located in the Southern part of Bali Island, and as a strategic tourism destination. The increased of the human activity has an important role to give an ecological pressure for the seawater ecosystem in the Benoa bay. Total suspended solid (TSS and turbidity is one of the important indicators that could be determining the quality of the seawater. As the estuary, Benoa bay received fresh water from the river discharge that also potentially carries any material to the bay. In addition, port activity is also has an important role in contributing a various material to the Benoa bay. From this research, we found that the TSS concentration and the turbidity are higher in the surface water and also in the bottom layer. TSS concentration and the turbidity also varied from the bay mouth trough the line of vessel onto the inner of bay. TSS concentration and turbidity in the bay mouth has a smaller concentration rather than in the inner part of bay. TSS concentration and turbidity in the inner of bay could be caused by the port activity. In addition, seawater circulation is also has an importan factor to contributing the TSS concentration and the turbidity. Sea current would be erroted the seabottom and with the different shape of the topography could be increased the TSS and turbidity.

Motion of charged suspended particle in a non-Newtonian fluid between two long parallel plates

Energy Technology Data Exchange (ETDEWEB)

Abd Elkhalek, M M [Nuclear Research Center-Atomic Energy Authority, Cairo (Egypt)

1997-12-31

The motion of charged suspended particle in a non-Newtonian fluid between two long parallel plates is discussed. The equation of motion of a suspended particle was suggested by Closkin. The equations of motion are reduced to ordinary differential equations by similarity transformation and solved numerically by using Runge-Kutta method. The trajectories of particles are calculated by integrating the equation of motion of a single particle. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. The effect of solid particles on flow properties are discussed. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically. 4 figs.

Motion of Charged Suspended Particle in a Non-Newtonian Fluid between Two Long Parallel Plated

International Nuclear Information System (INIS)

Abd-El Khalek, M.M.

1998-01-01

The motion of charged suspended particle in a non-Newtonian fluid between two long parallel plates is discussed. The equation of motion of a suspended particle was suggested by Closkin. The equations of motion are reduced to ordinary differential equations by similarity transformations and solved numerically by using the Runge-Kutta method. The trajectories of particles are calculated by integrating the equation of motion of a single particle. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. The effects of solid particles on flow properties are discussed. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically

Treatment of wastewater containing phenol using a tubular ceramic membrane bioreactor.

Science.gov (United States)

Ersu, C B; Ong, S K

2008-02-01

The performance of a membrane bioreactor (MBR) with a tubular ceramic membrane for phenol removal was evaluated under varying hydraulic retention times (HRT) and a fixed sludge residence time (SRT) of 30 days. The tubular ceramic membrane was operated with a mode of 15 minutes of filtration followed by 15 seconds of permeate backwashing at a flux of 250 l m(-2)hr(-1) along with an extended backwashing of 30 seconds every 3 hours of operation, which maintained the transmembrane pressure (TMP) below 100 kPa. Using a simulated municipal wastewater with varying phenol concentrations, the chemical oxygen demand (COD) and phenol removals observed were greater than 88% with excellent suspended solids (SS) removal of 100% at low phenol concentrations (approx. 100 mg l(-1) of phenol). Step increases in phenol concentration showed that inhibition was observed between 600 to 800 mg l(-1) of phenol with decreased sludge production rate, mixed liquor suspended solids (MLSS) concentration, and removal performance. The sludge volume index (SVI) of the biomass increased to about 450 ml g(-1) for a phenol input concentration of 800 mg l(-1). When the phenol concentration was decreased to 100 mg l(-1), the ceramic tubular MBR was found to recover rapidly indicating that the MBR is a robust system retaining most of the biomass. Experimental runs using wastewater containing phenol indicated that the MBR can be operated safely without upsets for concentrations up to 600 mg l(-1) of phenol at 2-4 hours HRT and 30 days SRT.

Suspended ceilings

Energy Technology Data Exchange (ETDEWEB)

Talamo, C.

1991-05-01

The retrofitting of existing conventional ceiling systems to suspended ceiling type systems represents an interesting energy savings solution since this method, in addition to providing additional protection against space heat loss and thermal bridges, also creates the possibility of housing, in the void, additional mechanical and electrical lines which may be necessary due to other savings interventions. This paper reviews the various suspended ceiling systems (e.g., those making use of mineral fibre, gypsum panels, wood, vermiculite, etc.) currently marketed in Europe, and reports, for each, some key technical, economic and architectural advantages which include thermal efficiency, noise abatement, as well as, resistance to fire and humidity. Information is also given on the relative installation and maintenance requirements.

Magnesium-rich minerals in sediment and suspended particulates of South Florida water bodies: implications for turbidity.

Science.gov (United States)

Harris, W G; Fisher, M M; Cao, X; Osborne, T; Ellis, L

2007-01-01

Fine sediments in shallow water bodies such as Lake Okeechobee are prone to resuspension. Predominantly inorganic "mud" sediment that covers approximately 670 km2 of the lake has been recognized as a persistent source of turbidity. The objective of this study was to determine if mineral components of sediments in Lake Okeechobee and water conveyances of the northern Everglades also occur as suspended sediment and hence constitute a potential abiotic contributor to turbidity. Sediment samples were collected from nine stations within the lake and eight locations north of Water Conservation Area 2A in the Everglades. Water samples were also collected at selected locations. The silt and clay mineralogy of sediment and suspended particles was determined using X-ray diffraction, thermogravimetry, scanning-electron microscopy, energy-dispersive X-ray elemental microanalysis, and high-resolution transmission-electron microscopy. Clay fractions of the lake sediment contained the Mg silicate minerals sepiolite and palygorskite, along with smectite, dolomite, calcite, and kaolinite. Sediment silt fractions were dominated by carbonates and/or quartz, with smaller amounts of Ca phosphates and sepiolite. Mineralogy of the mud sediment was similar to that reported for geologic phosphate deposits. This suggests that the mud sediment might have accumulated by stream transport of minerals from these deposits. Suspended solids and mud-sediment mineralogy were similar, except that smectite was more abundant in suspended solids. Everglade samples also contained Mg-rich minerals. The small size, low density, and fibrous or platy nature of the prevalent mud sediment minerals make them an abiotic, hydrodynamically sensitive source of persistent turbidity in a shallow lake. Mitigation efforts focused exclusively on P-induced biogeochemical processes do not address the origin or effects of these minerals. Ecological management issues such as turbidity control, P retention, geologic P input

Spatial and temporal variation in suspended sediment, organic matter, and turbidity in a Minnesota prairie river: implications for TMDLs.

Science.gov (United States)

Lenhart, Christian F; Brooks, Kenneth N; Heneley, Daniel; Magner, Joseph A

2010-06-01

The Minnesota River Basin (MRB), situated in the prairie pothole region of the Upper Midwest, contributes excessive sediment and nutrient loads to the Upper Mississippi River. Over 330 stream channels in the MRB are listed as impaired by the Minnesota Pollution Control Agency, with turbidity levels exceeding water quality standards in much of the basin. Addressing turbidity impairment requires an understanding of pollutant sources that drive turbidity, which was the focus of this study. Suspended volatile solids (SVS), total suspended solids (TSS), and turbidity were measured over two sampling seasons at ten monitoring stations in Elm Creek, a turbidity impaired tributary in the MRB. Turbidity levels exceeded the Minnesota standard of 25 nephelometric units in 73% of Elm Creek samples. Turbidity and TSS were correlated (r (2) = 0.76), yet they varied with discharge and season. High levels of turbidity occurred during periods of high stream flow (May-June) because of excessive suspended inorganic sediment from watershed runoff, stream bank, and channel contributions. Both turbidity and TSS increased exponentially downstream with increasing stream power, bank height, and bluff erosion. However, organic matter discharged from wetlands and eutrophic lakes elevated SVS levels and stream turbidity in late summer when flows were low. SVS concentrations reached maxima at lake outlets (50 mg/l) in August. Relying on turbidity measurements alone fails to identify the cause of water quality impairment whether from suspended inorganic sediment or organic matter. Therefore, developing mitigation measures requires monitoring of both TSS and SVS from upstream to downstream reaches.

Twelve Years of Monitoring Phosphorus and Suspended-Solids Concentrations and Yields in the North Fork Ninnescah River above Cheney Reservoir, South-Central Kansas 1997-2008

Science.gov (United States)

Stone, Mandy L.; Graham, Jennifer L.; Ziegler, Andrew C.

2009-01-01

Cheney Reservoir, located on the North Fork Ninnescah River in south-central Kansas, is the primary water supply for the city of Wichita and an important recreational resource. Concerns about taste-and-odor occurrences in Cheney Reservoir have drawn attention to potential pollutants, including total phosphorus (TP) and total suspended solids (TSS). July 2009 was the 15th anniversary of the establishment of the Cheney Reservoir Watershed pollution management plan. The U.S. Geological Survey (USGS), in cooperation with the city of Wichita, has collected water-quality data in the basin since 1996, and has monitored water quality continuously on the North Fork Ninnescah River since 1998. This fact sheet describes 12 years (1997-2008) of computed TP and TSS data and compares these data with water-quality goals for the North Fork Ninnescah River, the main tributary to Cheney Reservoir.

Development of a flocculation sub-model for a 3-D CFD model based on rectangular settling tanks.

Science.gov (United States)

Gong, M; Xanthos, S; Ramalingam, K; Fillos, J; Beckmann, K; Deur, A; McCorquodale, J A

2011-01-01

To assess performance and evaluate alternatives to improve the efficiency of rectangular Gould II type final settling tanks (FSTs), New York City Department of Environmental Protection and City College of NY developed a 3D computer model depicting the actual structural configuration of the tanks and the current and proposed hydraulic and solids loading rates. Fluent 6.3.26™ was the base platform for the computational fluid dynamics (CFD) model, for which sub-models of the SS settling characteristics, turbulence, flocculation and rheology were incorporated. This was supplemented by field and bench scale experiments to quantify the coefficients integral to the sub-models. The 3D model developed can be used to consider different baffle arrangements, sludge withdrawal mechanisms and loading alternatives to the FSTs. Flocculation in the front half of the rectangular tank especially in the region before and after the inlet baffle is one of the vital parameters that influences the capture efficiency of SS. Flocculation could be further improved by capturing medium and small size particles by creating an additional zone with an in-tank baffle. This was one of the methods that was adopted in optimizing the performance of the tank where the CCNY 3D CFD model was used to locate the in-tank baffle position. This paper describes the development of the flocculation sub-model and the relationship of the flocculation coefficients in the known Parker equation to the initial mixed liquor suspended solids (MLSS) concentration X0. A new modified equation is proposed removing the dependency of the breakup coefficient to the initial value of X0 based on preliminary data using normal and low concentration mixed liquor suspended solids values in flocculation experiments performed.

Successful bioaugmentation of an activated sludge reactor with Rhodococcus sp. YYL for efficient tetrahydrofuran degradation

International Nuclear Information System (INIS)

Yao, Yanlai; Lu, Zhenmei; Zhu, Fengxiang; Min, Hang; Bian, Caimiao

2013-01-01

Highlights: • Rhodococcus sp. YYL is an efficient tetrahydrofuran-degrading strain. • Strain YYL was used to augment an activated sludge system for THF degradation. • Successful bioaugmentation was achieved only by coinoculation of strain YYL and the two bacilli. • Successful bioaugmentation of the system resulted in efficient THF degradation. -- Abstract: The exchange of tetrahydrofuran (THF)-containing wastewater should significantly affect the performance of an activated sludge system. In this study, the feasibility of using THF-degrading Rhodococcus sp. strain YYL to bioaugment an activated sludge system treating THF wastewater was explored. As indicated by a DGGE analysis, strain YYL alone could not dominate the system, with the concentration of mixed liquor suspended solids (MLSS) decreasing to nearly half of the initial concentration after 45 d, and the microbial diversity was found to be significantly reduced. However, after the reactor was augmented with the mixed culture of strain YYL and two bacilli initially coexisting in the enriched isolation source, strain YYL quickly became dominant in the system and was incorporated into the activated sludge. The concentration of MLSS increased from 2.1 g/L to 7.3 g/L in 20 d, and the efficiency of THF removal from the system was remarkably improved. After the successful bioaugmentation, more than 95% of THF was completely removed from the wastewater when 20 mM THF was continuously loaded into the system. In conclusion, our research first demonstrates that bioaugmentation of activated sludge system for THF degradation is feasible but that successful bioaugmentation should utilize a THF-degrading mixed culture as the inoculum, in which the two bacilli might help strain YYL colonize in activated sludge by co-aggregation

40 CFR 230.21 - Suspended particulates/turbidity.

Science.gov (United States)

2010-07-01

... Impacts on Physical and Chemical Characteristics of the Aquatic Ecosystem § 230.21 Suspended particulates/turbidity. (a) Suspended particulates in the aquatic ecosystem consist of fine-grained mineral particles..., and man's activities including dredging and filling. Particulates may remain suspended in the water...

Assessing catchment-scale erosion and yields of suspended solids from improved temperate grassland.

Science.gov (United States)

Bilotta, G S; Krueger, T; Brazier, R E; Butler, P; Freer, J; Hawkins, J M B; Haygarth, P M; Macleod, C J A; Quinton, J N

2010-03-01

This paper quantifies the yields of suspended solids (SS) from a headwater catchment managed as improved temperate grassland, providing the first direct, catchment-scale evidence of the rates of erosion from this land-use in the UK and assessing the threat posed to aquatic ecosystems. High-resolution monitoring of catchment hydrology and the concentrations of SS and volatile organic matter (VOM) were carried out in the first-order channel of the Den Brook headwater catchment in Devon (UK) during the 2006-2007 hydrological season. The widely used 'rating curve' (discharge-concentration) approach was employed to estimate yields of SS, but as demonstrated by previous researchers, this study showed that discharge is a poor predictor of SS concentrations and therefore any yields estimated from this technique are likely to be highly uncertain. Nevertheless, for the purpose of providing estimates of yields that are comparable to previous studies on other land uses/sources, this technique was adopted albeit in an uncertainty-based framework. The findings suggest that contrary to the common perception, grasslands can be erosive landscapes with SS yields from this catchment estimated to be between 0.54 and 1.21 t ha(-1) y(-1). In terms of on-site erosion problems, this rate of erosion does not significantly exceed the commonly used 'tolerable' threshold in the UK ( approximately 1 t ha(-1) y(-1)). In terms of off-site erosion problems, it is argued here that the conventional expression of SS yield as a bulk annual figure has little relevance to the water quality and ecological status of surface waters and therefore an alternative technique (the concentration-frequency curve) is developed within this paper for the specific purpose of assessing the ecological threat posed by the delivery of SS into surface waters. This technique illustrates that concentrations of SS recorded at the catchment outlet frequently exceed the water quality guidelines, such as those of the EU

Effect of trace amounts of polyacrylamide (PAM) on long-term performance of activated sludge

International Nuclear Information System (INIS)

Luo, Yuan-ling; Yang, Zhao-hui; Xu, Zheng-yong; Zhou, Ling-jun; Zeng, Guang-ming; Huang, Jing; Xiao, Yong; Wang, Li-ke

2011-01-01

This study aims at evaluating the impacts of PAM addition on activated sludge performance. Four lab-scale sequencing batch reactors (SBRs), each with a working volume of 3 L, were investigated with different PAM concentrations. Experiments were conducted with varying organic loading rate and the sludge volume index (SVI), particle size, zeta potential, specific oxygen uptake rate (SOUR), mixed liquor suspended solids (MLSS), COD and ammonium removal efficiency were monitored over a 105-day period. The results showed that all of the PAM addition not only improved the removal efficiencies of COD and ammonium, but also exhibited some advantages on sludge performance. It was found that the sludge performance of settling property, flocculation and microbial activity increased with increasing concentration of PAM. However, high level of PAM (1 mg/L) led to the formation of large amounts of loose-structure flocs, which eliminated dissolved oxygen transfer and caused the sludge disintegration, resulting in bad settleability and lower microbial activity. In this way, when the dosage of PAM was 0.1 mg/L, the sludge had the best settling property and activity.

Biosynthesis of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) by bacterial community from propylene oxide saponification wastewater residual sludge.

Science.gov (United States)

Wang, Yiwei; Zhu, Ying; Gu, Pengfei; Li, Yumei; Fan, Xiangyu; Song, Dongxue; Ji, Yan; Li, Qiang

2017-05-01

The saponification wastewater from the process of propylene oxide (PO) production is contaminated with high chemical oxygen demand (COD) and chlorine contents. Although the activated sludge process could treat the PO saponification wastewater effectively, the residual sludge was difficult to be disposed properly. In this research, microbes in PO saponification wastewater residual sludge were acclimated to produce poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) from volatile fatty acids. Through Miseq Illumina highthroughput sequencing, the bacterial community discrepancy between the original and the acclimated sludge samples were analyzed. The proportions of Bacillus, Acinetobacter, Brevundimonas and Pseudomonas, the potential PHBV-producers in the residual sludge, were all obviously increased. In the batch fermentation, the production of PHBV could achieve 4.262g/L at 300min, with the content increased from 0.04% to 23.67% of mixed liquor suspended solid (MLSS) in the acclimated sludge, and the COD of the PO saponification wastewater was also decreased in the fermentation. This work would provide an effective solution for the utilization of PO saponification wastewater residual sludge. Copyright © 2017 Elsevier B.V. All rights reserved.

A New Measure for Transported Suspended Sediment

Science.gov (United States)

Yang, Q.

2017-12-01

Non-uniform suspended sediment plays an important role in many geographical and biological processes. Despite extensive study, understanding to it seems to stagnate when times to consider non-uniformity and non-equilibrium scenarios comes. Due to unsatisfactory reproducibility, large-scaled flume seems to be incompetent to conduct more fundamental research in this area. To push the realm a step further, experiment to find how suspended sediment exchanges is conducted in a new validated equipment, in which turbulence is motivated by oscillating grids. Analysis shows that 1) suspended sediment exchange is constrained by ωS invariance, 2) ωS of the suspended sediment that certain flow regime could support is unique regardless of the sediment gradation and 3) the more turbulent the flow, the higher ωS of the suspension the flow could achieve. A new measure for suspended sediment ωS, the work required to sustain sediment in suspension transport mode if multiplied by gravitational acceleration, is thus proposed to better describe the dynamics of transported suspended sediment. Except for the further understanding towards suspended sediment transportation mechanics, with this energy measure, a strategy to distribute total transport capacity to different fractions could be derived and rational calculation of non-uniform sediment transport capacity under non-equilibrium conditions be possible.

Single-objective vs. multi-objective autocalibration in modelling total suspended solids and phosphorus in a small agricultural watershed with SWAT.

Science.gov (United States)

Rasolomanana, Santatriniaina Denise; Lessard, Paul; Vanrolleghem, Peter A

2012-01-01

To obtain greater precision in modelling small agricultural watersheds, a shorter simulation time step is beneficial. A daily time step better represents the dynamics of pollutants in the river and provides more realistic simulation results. However, with a daily evaluation performance, good fits are rarely obtained. With the Shuffled Complex Evolution (SCE) method embedded in the Soil and Water Assessment Tool (SWAT), two calibration approaches are available, single-objective or multi-objective optimization. The goal of the present study is to evaluate which approach can improve the daily performance with SWAT, in modelling flow (Q), total suspended solids (TSS) and total phosphorus (TP). The influence of weights assigned to the different variables included in the objective function has also been tested. The results showed that: (i) the model performance depends not only on the choice of calibration approach, but essentially on the influential parameters; (ii) the multi-objective calibration estimating at once all parameters related to all measured variables is the best approach to model Q, TSS and TP; (iii) changing weights does not improve model performance; and (iv) with a single-objective optimization, an excellent water quality modelling performance may hide a loss of performance of predicting flows and unbalanced internal model components.

Accuracy of different sensors for the estimation of pollutant concentrations (total suspended solids, total and dissolved chemical oxygen demand) in wastewater and stormwater.

Science.gov (United States)

Lepot, Mathieu; Aubin, Jean-Baptiste; Bertrand-Krajewski, Jean-Luc

2013-01-01

Many field investigations have used continuous sensors (turbidimeters and/or ultraviolet (UV)-visible spectrophotometers) to estimate with a short time step pollutant concentrations in sewer systems. Few, if any, publications compare the performance of various sensors for the same set of samples. Different surrogate sensors (turbidity sensors, UV-visible spectrophotometer, pH meter, conductivity meter and microwave sensor) were tested to link concentrations of total suspended solids (TSS), total and dissolved chemical oxygen demand (COD), and sensors' outputs. In the combined sewer at the inlet of a wastewater treatment plant, 94 samples were collected during dry weather, 44 samples were collected during wet weather, and 165 samples were collected under both dry and wet weather conditions. From these samples, triplicate standard laboratory analyses were performed and corresponding sensors outputs were recorded. Two outlier detection methods were developed, based, respectively, on the Mahalanobis and Euclidean distances. Several hundred regression models were tested, and the best ones (according to the root mean square error criterion) are presented in order of decreasing performance. No sensor appears as the best one for all three investigated pollutants.

Desorption of radioactive cesium by seawater from the suspended particles in river water.

Science.gov (United States)

Onodera, Masaki; Kirishima, Akira; Nagao, Seiya; Takamiya, Kouichi; Ohtsuki, Tsutomu; Akiyama, Daisuke; Sato, Nobuaki

2017-10-01

In 2011, the accident at the Fukushima-Daiichi nuclear power plant dispersed radioactive cesium throughout the environment, contaminating the land, rivers, and sea. Suspended particles containing clay minerals are the transportation medium for radioactive cesium from rivers to the ocean because cesium is strongly adsorbed between the layers of clay minerals, forming inner sphere complexes. In this study, the adsorption and desorption behaviors of radioactive cesium from suspended clay particles in river water have been investigated. The radioactive cesium adsorption and desorption experiments were performed with two kinds of suspended particulate using a batch method with 137 Cs tracers. In the cesium adsorption treatment performed before the desorption experiments, simulated river water having a total cesium concentration ([ 133+137 Cs + ] total ) of 1.3 nM (10 -9  mol/L) was used. The desorption experiments were mainly conducted at a solid-to-liquid ratio of 0.17 g/L. The desorption agents were natural seawater collected at 10 km north of the Fukushima-Daiichi nuclear power plant, artificial seawater, solutions of NaCl, KCl, NH 4 Cl, and 133 CsCl, and ultrapure water. The desorption behavior, which depends on the preloaded cesium concentration in the suspended particles, was also investigated. Based on the cesium desorption experiments using suspended particles, which contained about 1000 ng/g loaded cesium, the order of cesium desorption ratios for each desorption agent was determined as 1 M NaCl (80%) > 470 mM NaCl (65%) > 1 M KCl (30%) ≈ seawater (natural seawater and Daigo artificial seawater) > 1 M NH 4 Cl (20%) > 1 M 133 CsCl (15%) ≫ ultrapure water (2%). Moreover, an interesting result was obtained: The desorption ratio in the 470 mM NaCl solution was much higher than that in seawater, even though the Na + concentrations were identical. These results indicate that the cesium desorption mechanism is not a simple ion exchange reaction

Impact of surface and residual stresses and electro-/magnetostatic axial loading on the suspended nanomechanical based mass sensors: A theoretical study

Czech Academy of Sciences Publication Activity Database

Stachiv, Ivo

2014-01-01

Roč. 115, č. 21 (2014), "214310-1"-"214310-7" ISSN 0021-8979 R&D Projects: GA ČR GAP107/12/0800 Institutional support: RVO:68378271 Keywords : suspended nanomechanical resonators * mass sensors Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2014

Characterization and radionuclides sorption of suspended particulate matters in freshwater according to their settling kinetics

International Nuclear Information System (INIS)

Brach-Papa, C.; Boyer, P.; Amielh, M.; Anselmet, F.

2004-01-01

In freshwater, the transfers of radionuclides depend both on exchanges between liquid and solid phases and on mass transfers between suspended matter and bottom sediment. Whereas the former ones depend on chemical processes (such as sorption/desorption, complexation, the latter ones are regulated by hydrological and sedimentary considerations (dispersion, erosion, deposit closely related to the interactions between flow, suspended matter and bed sediment. Some of our previous studies highlight the need to consider the matter heterogeneity and its specific sediment dynamics to correctly report the inhomogeneity of fluxes in time and in space. These considerations lead us to develop experimental methods to distinguish the different matter classes, present in natural water, mainly according to their erosion threshold and settling kinetics. In this context, this paper presents the experimental protocol TALISMEN to characterize a natural bulk suspension according the identification of its main settling kinetics groups. In a first step, this identification is achieved by the use of a settling tank, that allows the monitoring of the suspended solid concentration at various depths, combined to a vertical mono-dimensional settling model applying a multi-class approach. In a second step, the particle groups are isolated and their physico-chemical properties are determined ( i.e mineral composition, specific surface area, particulate organic carbon, in order to fully characterized them. In a last one, the sorption property of each group toward radionuclides is determined by the measurements of its distribution coefficients (Kd). The results confirm the interest to consider these heterogeneities for the modelling of the radionuclides transfer in freshwater. From one group to other, these heterogeneities appear at two levels: 1) their sediment dynamics and 2) their radionuclides sorption properties. These conclusions can be equally applying to others xenobiotics as heavy metals

Intermodal resonance of vibrating suspended cables

NARCIS (Netherlands)

Rienstra, S.W.

2010-01-01

The weakly nonlinear free vibrations of a single suspended cable, or a coupled system of suspended cables, may be classified as gravity modes (no tension variations to leading order) and elasto-gravity modes (tension and vertical displacement equally important). It was found earlier [12] that the

Effects of Humic Acid and Suspended Solids on the Removal of Heavy Metals from Water by Adsorption onto Granular Activated Carbon.

Science.gov (United States)

Sounthararajah, Danious P; Loganathan, Paripurnanda; Kandasamy, Jaya; Vigneswaran, Saravanamuthu

2015-08-27

Heavy metals constitute some of the most dangerous pollutants of water, as they are toxic to humans, animals, and aquatic organisms. These metals are considered to be of major public health concern and, therefore, need to be removed. Adsorption is a common physico-chemical process used to remove heavy metals. Dissolved organic carbon (DOC) and suspended solids (SS) are associated pollutants in water systems that can interact with heavy metals during the treatment process. The interactions of DOC and SS during the removal of heavy metals by granular activated carbon were investigated in batch and fixed-bed column experiments. Batch adsorption studies indicated that Langmuir adsorption maxima for Pb, Cu, Zn, Cd, and Ni at pH 6.5 were 11.9, 11.8, 3.3, 2.0, and 1.8 mg/g, respectively. With the addition of humic acid (HA) (DOC representative), they were 7.5, 3.7, 3.2, 1.6, and 2.5 mg/g, respectively. In the column experiment, no breakthrough (complete removal) was obtained for Pb and Cu, but adding HA provided a breakthrough in removing these metals. For Zn, Cd and Ni, this breakthrough occurred even without HA being added. Adding kaolinite (representative of SS) had no effect on Pb and Cu, but it did on the other metals.

Transformation and sorption of illicit drug biomarkers in sewer systems: understanding the role of suspended solids in raw wastewater

DEFF Research Database (Denmark)

Ramin, Pedram; Brock, Andreas Libonati; Polesel, Fabio

2016-01-01

substrates (primary metabolic processes) and transformation of illicit drug biomarkers (secondary metabolic processes) by suspended biomass. Sixteen drug biomarkers were targeted, including mephedrone, methadone, cocaine, heroin, codeine and tetrahydrocannabinol (THC) and their major human metabolites. Batch...

Anaerobic treatment of complex wastewater and waste activated sludge - Appl. of an upflow anaerobic solid removal (UASR).

NARCIS (Netherlands)

Zeeman, G.; Sanders, W.T.M.; Wang, K.Y.; Lettinga, G.

1997-01-01

The application of one phase anaerobic wastewater systems for the treatment of complex wastewaters containing high amounts of suspended solids or lipids is usually limited by accumulation of these compounds in the sludge bed. This accumulation reduces the solid retention time and methanogenic

Numerical analysis of the motion of a suspended charged particle in multi-phase flow. Vol. 2

Energy Technology Data Exchange (ETDEWEB)

El-khalek, M M [Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

The motion of a suspended charged particle in a two component viscous fluid through two infinite parallel plates was studied. The motion takes place under constant magnetic field normal to the plane of the motion. The effect of some parameters as particle volume, fluid density, viscosity of the fluid, and the magnetic force used on the motion were investigated. The particle is assumed moving initially from the midpoint of the channel with a velocity equal to the velocity of the fluid. The trajectory of solid spherical suspended charged particle is calculated by integrating the equations of motion of a single particle. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. The differential equations of motion were numerically solved by Runge-Kutta method. Some conclusions about the path lines were deduced. 5 figs.

Quantification of Surface Suspended Sediments along a River Dominated Coast with NOAA AVHRR and SeaWiFS Measurements: Louisiana, USA

Science.gov (United States)

Myint, S. W.; Walker, N. D.

2002-01-01

The ability to quantify suspended sediment concentrations accurately over both time and space using satellite data has been a goal of many environmental researchers over the past few decades This study utilizes data acquired by the NOAA Advanced Very High Resolution Radiometer (AVHRR) and the Orbview-2 Sea-viewing wide field-of-view (SeaWiFS) ocean colour sensor, coupled with field measurements to develop statistical models for the estimation of near-surface suspended sediment and suspended solids "Ground truth" water samples were obtained via helicopter, small boat and automatic water sampler within a few hours of satellite overpasses The NOAA AVHRR atmospheric correction was modified for the high levels of turbidity along the Louisiana coast. Models were developed based on the field measurements and reflectance/radiance measurements in the visible and near infrared Channels of NOAA-14 and Orbview-2 SeaWiFS. The best models for predicting surface suspended sediment concentrations were obtained with a NOAA AVHRR Channel 1 (580-680nm) cubic model, Channel 2 (725-1100 nm) linear mod$ and SeaWiFs Channel 6 (660-68Onm) power modeL The suspended sediment models developed using SeaWiFS Channel 5 (545-565 nm) were inferior, a result that we attribute mainly to the atmospheric correction technique, the shallow depth of the water samples and absorption effects from non-sediment water constituents.

Avaliação da concentração de mercúrio em sedimentos e material particulado no rio Acre, estado do Acre, Brasil Mercury concentration assessment in botton sediments and suspended solids from Acre river, in the State of Acre, Brazil

Directory of Open Access Journals (Sweden)

Artur Fernando Silva Mascarenhas

2004-01-01

Full Text Available A avaliação dos teores de mercúrio em sistemas aquáticos sem influência direta de fontes antropogênicas conhecidas não tem sido conduzida com freqüência na região Amazônica. Visando contribuir para esclarecer a ocorrência de valores elevados de Hg em peixes consumidos pela população de Rio Branco - AC, o Instituto Evandro Chagas - IEC, realizou um estudo para quantificar os teores de Hg em sedimentos de fundo e material particulado no rio Acre e alguns afluentes, além da caracterização físico-química das águas entre as cidades de Brasiléia e Assis Brasil. As amostras de sedimentos foram peneiradas na fração Mercury levels assessment in aquatic systems areas without influences of antropogenic sources have not been well studied in the Amazon region. For the identification of the origin of high values of Hg in fish consumed by population of Rio Branco City - AC, the Evandro Chagas Institute - IEC, studied the mercury levels in sediments, suspended solids and studied also the physical-chemical characterization of waters, in the Acre river and also some in afluents, between Brasiléia and Assis Brasil cities. Bottom sediments samples were sieved to <250 mesh fraction after drying. The suspended solid was obtained by precipitation with Al2SO4. About 250 mg of the material was submitted the acid digestion and the determinations of Hg were made by Could Vapor Atomic Absorption Spectrometry. The physical-chemical parameters pH, electric conductivity, temperature and dissolved total solids, were studied in the field, by potenciometric methods. The Hg levels in bottom sediments range 0,018 and 0,184 mug g-1, mean of 0,054 ± 0,034 mug g-1, while the suspended solids varied between 0,067 and 0,220 mug g-1, average of 0,098 ± 0,037 mug g-1. The waters were slightly acid with pH varying among 5,80 - 6,95 and conductivity electric 151,60 - 1.151,00 muS cm-1. The mercury levels in the analyzed materials was below of standard levels for

Mixing and solid suspension in a stirred precipitator

International Nuclear Information System (INIS)

Chang, T.P.

1986-04-01

Full-scale mixing and solid suspension studies have been conducted to determine the optimum agitator design for precipitators used in plutonium processing. Design considerations include the geometry of precipitator vessels, feed locations, flow patterns, and product requirements. Evaluations of various agitator designs are based on their capabilities: (1) to achieve uniform mixing of reactants in minimum time, (2) to suspend slurry uniformly throughout the vessel, and (3) to minimize power consumption without inducing air entrainment. Tests of full-scale agitator designs showed that significant improvements in mixing, solid suspension, and energy consumption were achieved

Ultrasonic device for real-time sewage velocity and suspended particles concentration measurements.

Science.gov (United States)

Abda, F; Azbaid, A; Ensminger, D; Fischer, S; François, P; Schmitt, P; Pallarès, A

2009-01-01

In the frame of a technological research and innovation network in water and environment technologies (RITEAU, Réseau de Recherche et d'Innovation Technologique Eau et Environnement), our research group, in collaboration with industrial partners and other research institutions, has been in charge of the development of a suitable flowmeter: an ultrasonic device measuring simultaneously the water flow and the concentration of size classes of suspended particles. Working on the pulsed ultrasound principle, our multi-frequency device (1 to 14 MHz) allows flow velocity and water height measurement and estimation of suspended solids concentration. Velocity measurements rely on the coherent Doppler principle. A self developed frequency estimator, so called Spectral Identification method, was used and compared to the classical Pulse-Pair method. Several measurements campaigns on one wastewater collector of the French city of Strasbourg gave very satisfactory results and showed smaller standard deviation values for the Doppler frequency extracted by the Spectral Identification method. A specific algorithm was also developed for the water height measurements. It relies on the water surface acoustic impedance rupture and its peak localisation and behaviour in the collected backscattering data. This algorithm was positively tested on long time measurements on the same wastewater collector. A large part of the article is devoted to the measurements of the suspended solids concentrations. Our data analysis consists in the adaptation of the well described acoustic behaviour of sand to the behaviour of wastewater particles. Both acoustic attenuation and acoustic backscattering data over multiple frequencies are analyzed for the extrapolation of size classes and respective concentrations. Under dry weather conditions, the massic backscattering coefficient and the overall size distribution showed similar evolution whatever the measurement site was and were suggesting a global

А mathematical model study of suspended monorail

OpenAIRE

Viktor GUTAREVYCH

2012-01-01

The mathematical model of suspended monorail track with allowance for elastic strain which occurs during movement of the monorail carriage was developed. Standard forms for single span and double span of suspended monorail sections were established.

ASSESSMENT OF THE ABILITY OF STANDARD SLURRY PUMPS TO MIX SOLIDS WITH LIQUIDS IN TANK 50H

Energy Technology Data Exchange (ETDEWEB)

Poirier, M.

2011-11-11

Tank 50H is the feed tank for the Saltstone Production Facility (SPF). In the summer of 2011, Tank 50H contained two standard slurry pumps and two quad volute slurry pumps. Current requirements for mixing operation is to run three pumps for one hour prior to initiating a feed transfer to SPF. Savannah River Site (SRS) Liquid Waste moved both of the Quad Volute pumps from Tank 50H to Tank 51H to replace pumps in Tank 51H that were failing. In addition, one of the standard pumps in Tank 50H exhibits high seal leakage and vibration. SRS Liquid Waste requested Savannah River National Laboratory (SRNL) to conduct a study to evaluate the feasibility of mixing the contents of Tank 50H with one to three standard slurry pumps. To determine the pump requirements to mix solids with liquids in Tank 50H, the author reviewed the pilot-scale blending work performed for the Small Column Ion Exchange Process (SCIX), SRNL computational fluid dynamics (CFD) modeling, Tank 50H operating experience, and the technical literature, and applied the results to Tank 50H to determine the number, size, and operating parameters of pumps needed to mix the solid particles with the liquid in Tank 50H. The analysis determined pump requirements to suspend the solids with no 'dead zones', but did not determine the pump requirements to produce a homogeneous suspension. In addition, the analysis determined the pump requirements to prevent the accumulation of a large amount of solid particles under the telescoping transfer pump. The conclusions from this analysis follow: (1) The analysis shows that three Quad Volute pumps should be able to suspend the solid particles expected ({approx}0.6 g/L insoluble solids, {approx}5 micron) in Tank 50H. (2) Three standard slurry pumps may not be able to suspend the solid particles in Tank 50H; (3) The ability of two Quad Volute pumps to fully suspend all of the solid particles in Tank 50H is marginal; and (4) One standard slurry pump should be able to

А mathematical model study of suspended monorail

Directory of Open Access Journals (Sweden)

Viktor GUTAREVYCH

2012-01-01

Full Text Available The mathematical model of suspended monorail track with allowance for elastic strain which occurs during movement of the monorail carriage was developed. Standard forms for single span and double span of suspended monorail sections were established.

Treatment of petroleum refinery wastewater using a sequential anaerobic-aerobic moving-bed biofilm reactor system based on suspended ceramsite.

Science.gov (United States)

Lu, Mang; Gu, Li-Peng; Xu, Wen-Hao

2013-01-01

In this study, a novel suspended ceramsite was prepared, which has high strength, optimum density (close to water), and high porosity. The ceramsite was used to feed a moving-bed biofilm reactor (MBBR) system with an anaerobic-aerobic (A/O) arrangement to treat petroleum refinery wastewater for simultaneous removal of chemical oxygen demand (COD) and ammonium. The hydraulic retention time (HRT) of the anaerobic-aerobic MBBR system was varied from 72 to 18 h. The anaerobic-aerobic system had a strong tolerance to shock loading. Compared with the professional emission standard of China, the effluent concentrations of COD and NH3-N in the system could satisfy grade I at HRTs of 72 and 36 h, and grade II at HRT of 18 h. The average sludge yield of the anaerobic reactor was estimated to be 0.0575 g suspended solid/g CODremoved. This work demonstrated that the anaerobic-aerobic MBBR system using the suspended ceramsite as bio-carrier could be applied to achieving high wastewater treatment efficiency.

Navigating environmental, economic, and technological trade-offs in the design and operation of submerged anaerobic membrane bioreactors (AnMBRs)

KAUST Repository

Pretel, R.

2015-12-01

© 2015 Elsevier Ltd. Anaerobic membrane bioreactors (AnMBRs) enable energy recovery from wastewater while simultaneously achieving high levels of treatment. The objective of this study was to elucidate how detailed design and operational decisions of submerged AnMBRs influence the technological, environmental, and economic sustainability of the system across its life cycle. Specific design and operational decisions evaluated included: solids retention time (SRT), mixed liquor suspended solids (MLSS) concentration, sludge recycling ratio (r), flux (J), and specific gas demand per membrane area (SGD). The possibility of methane recovery (both as biogas and as soluble methane in reactor effluent) and bioenergy production, nutrient recovery, and final destination of the sludge (land application, landfill, or incineration) were also evaluated. The implications of these design and operational decisions were characterized by leveraging a quantitative sustainable design (QSD) framework which integrated steady-state performance modeling across seasonal temperatures (using pilot-scale experimental data and the simulating software DESASS), life cycle cost (LCC) analysis, and life cycle assessment (LCA). Sensitivity and uncertainty analyses were used to characterize the relative importance of individual design decisions, and to navigate trade-offs across environmental, economic, and technological criteria. Based on this analysis, there are design and operational conditions under which submerged AnMBRs could be net energy positive and contribute to the pursuit of carbon negative wastewater treatment.

Effects of Humic Acid and Suspended Solids on the Removal of Heavy Metals from Water by Adsorption onto Granular Activated Carbon

Directory of Open Access Journals (Sweden)

Danious P. Sounthararajah

2015-08-01

Full Text Available Heavy metals constitute some of the most dangerous pollutants of water, as they are toxic to humans, animals, and aquatic organisms. These metals are considered to be of major public health concern and, therefore, need to be removed. Adsorption is a common physico-chemical process used to remove heavy metals. Dissolved organic carbon (DOC and suspended solids (SS are associated pollutants in water systems that can interact with heavy metals during the treatment process. The interactions of DOC and SS during the removal of heavy metals by granular activated carbon were investigated in batch and fixed-bed column experiments. Batch adsorption studies indicated that Langmuir adsorption maxima for Pb, Cu, Zn, Cd, and Ni at pH 6.5 were 11.9, 11.8, 3.3, 2.0, and 1.8 mg/g, respectively. With the addition of humic acid (HA (DOC representative, they were 7.5, 3.7, 3.2, 1.6, and 2.5 mg/g, respectively. In the column experiment, no breakthrough (complete removal was obtained for Pb and Cu, but adding HA provided a breakthrough in removing these metals. For Zn, Cd and Ni, this breakthrough occurred even without HA being added. Adding kaolinite (representative of SS had no effect on Pb and Cu, but it did on the other metals.

Occurrence of tributyltin (TBT)-resistant bacteria is not related to TBT pollution in Mekong River and coastal sediment: with a hypothesis of selective pressure from suspended solid.

Science.gov (United States)

Suehiro, Fujiyo; Mochizuki, Hiroko; Nakamura, Shinji; Iwata, Hisato; Kobayashi, Takeshi; Tanabe, Shinsuke; Fujimori, Yoshifumi; Nishimura, Fumitake; Tuyen, Bui Cach; Tana, Touch Seang; Suzuki, Satoru

2007-07-01

Tributyltin (TBT) is organotin compound that is toxic to aquatic life ranging from bacteria to mammals. This study examined the concentration of TBT in sediment from and near the Mekong River and the distribution of TBT-resistant bacteria. TBT concentrations ranged from TBT-resistant bacteria ranged TBT-resistant bacteria ranged from TBT in the sediment and of TBT-resistant bacteria were unrelated, and chemicals other than TBT might induce TBT resistance. TBT-resistant bacteria were more abundant in the dry season than in the rainy season. Differences in the selection process of TBT-resistant bacteria between dry and rainy seasons were examined using an advection-diffusion model of a suspended solid (SS) that conveys chemicals. The estimated dilution-diffusion time over a distance of 120 km downstream from a release site was 20 days during dry season and 5 days during rainy season, suggesting that bacteria at the sediment surface could be exposed to SS for longer periods during dry season.

Bench-Scale and Pilot-Scale Treatment Technologies for the Removal of Total Dissolved Solids from Coal Mine Water: A Review

Science.gov (United States)

Coal mine water (CMW) is typically treated to remove suspended solids, acidity, and soluble metals, but high concentrations of total dissolved solids (TDS) have been reported to impact the environment at several CMW discharge points. Consequently, various states have establishe...

Numerical simulation of bubble induced shear in membrane bioreactors: effects of mixed liquor rheology and membrane configuration.

Science.gov (United States)

Liu, Xuefei; Wang, Yuan; Waite, T David; Leslie, Greg

2015-05-15

A CFD model, incorporating an empirically determined rheology model and a porous media model, was developed to simulate bubble induced surface shear in membrane bioreactors configured with hollow fibre membranes with outer diameters ranging from 1.3 to 2.4 mm, arranged in vertically orientated modules with packing density from 200 to 560 m(2)/m(3). The rheology model was developed for mixed liquor suspended solids (MLSS) concentrations of 3 to 16 gL(-1) in the presence and absence of coagulant (generated by addition of a ferrous salt) for shear rates ranging from 0 to 500 s(-1). Experimentally determined particle relaxation times for the biological flocs in the mixed liquor, both in the absence and presence of iron, were negligible, consistent with an environment where positive buoyancy forces were greater than negative settling forces thereby allowing the sludge mixture to be modelled as a single continuous phase. The non-Newtonian behaviour of the mixed liquor was incorporated into the CFD simulations using an Ostwald-de Waele rheology model. Interactions between mixed liquor and hollow fibre membranes of different fibre size and packing density were described using a porous media model that was calibrated by empirical measurement of inertial loss coefficients over a range of viscosities (0.8 × 10(-3) to 2.1 × 10(-3) Pa.s) and velocities (0 to 0.35 m/s) typically encountered in full scale MBRs. Experimental results indicated that addition of iron salts resulted in an increase in MLSS and sludge viscosity. Shear stress is affected by both velocity and viscosity. The increase in sludge viscosity resulted in an increase in resistance to flow through the hollow fibre membrane bundles and, as a result, decreased the liquid flow velocities. CFD simulations provided insight on the effects of point of coagulant addition and MLSS concentration on bubble-induced shear over a range of industrially relevant conditions. A 12% increase in shear stress was observed when

Case studies on the physical-chemical parameters' variation during three different purification approaches destined to treat wastewaters from food industry.

Science.gov (United States)

Ghimpusan, Marieta; Nechifor, Gheorghe; Nechifor, Aurelia-Cristina; Dima, Stefan-Ovidiu; Passeri, Piero

2017-12-01

The paper presents a set of three interconnected case studies on the depuration of food processing wastewaters by using aeration & ozonation and two types of hollow-fiber membrane bioreactor (MBR) approaches. A secondary and more extensive objective derived from the first one is to draw a clearer, broader frame on the variation of physical-chemical parameters during the purification of wastewaters from food industry through different operating modes with the aim of improving the management of water purification process. Chemical oxygen demand (COD), pH, mixed liquor suspended solids (MLSS), total nitrogen, specific nitrogen (NH 4 + , NO 2 - , NO 3 - ) total phosphorous, and total surfactants were the measured parameters, and their influence was discussed in order to establish the best operating mode to achieve the purification performances. The integrated air-ozone aeration process applied in the second operating mode lead to a COD decrease by up to 90%, compared to only 75% obtained in a conventional biological activated sludge process. The combined purification process of MBR and ozonation produced an additional COD decrease of 10-15%, and made the Total Surfactants values to comply to the specific legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Kinetic coefficients for the biological treatment of tannery wastewater

International Nuclear Information System (INIS)

Haydar, S.

2008-01-01

Determination of kinetic coefficients for a particular wastewater is imperative for the rational design of biological treatment-facilities. The present study was undertaken with the objective of finding out kinetic coefficients for tannery wastewater. A bench-scale model of aerated lagoon, consisting of an aeration tank and final clarifier, was use to conduct the studies. The model was operated continuously for 96 days, by varying the detention times from 3 to 9 days. Influent for the aerated lagoon was settled tannery wastewater. Biochemical oxygen demand (BOD) of the influent and effluent and the mixed-liquor suspended solids (MLSS) of aeration tank were determined at various detention-times so as to generate data for kinetic coefficients. The kinetic coefficients k, Ks, Y and Ed were found to be 3.125 day/sup -1/, 488 mg/L, 0.64 and 0.035 day/sup -1/ respectively. Overall rate-constant of BOD, removal 'K' was also determined and was found to be 1.43 day/sup -1/. Kinetic coefficients were determined, at mean reactor-temperature of 30.2 degree C. These coefficients may be utilized for the design of biological-treatment facilities for tannery wastewater. (author)

Effect of trace amounts of polyacrylamide (PAM) on long-term performance of activated sludge.

Science.gov (United States)

Luo, Yuan-ling; Yang, Zhao-hui; Xu, Zheng-yong; Zhou, Ling-jun; Zeng, Guang-ming; Huang, Jing; Xiao, Yong; Wang, Li-ke

2011-05-15

This study aims at evaluating the impacts of PAM addition on activated sludge performance. Four lab-scale sequencing batch reactors (SBRs), each with a working volume of 3L, were investigated with different PAM concentrations. Experiments were conducted with varying organic loading rate and the sludge volume index (SVI), particle size, zeta potential, specific oxygen uptake rate (SOUR), mixed liquor suspended solids (MLSS), COD and ammonium removal efficiency were monitored over a 105-day period. The results showed that all of the PAM addition not only improved the removal efficiencies of COD and ammonium, but also exhibited some advantages on sludge performance. It was found that the sludge performance of settling property, flocculation and microbial activity increased with increasing concentration of PAM. However, high level of PAM (1mg/L) led to the formation of large amounts of loose-structure flocs, which eliminated dissolved oxygen transfer and caused the sludge disintegration, resulting in bad settleability and lower microbial activity. In this way, when the dosage of PAM was 0.1mg/L, the sludge had the best settling property and activity. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Analysis of the nitrifying bacterial community in BioCube sponge media using fluorescent in situ hybridization (FISH) and microelectrodes.

Science.gov (United States)

Chae, Kyu-Jung; Rameshwar, T; Jang, Am; Kim, Sung H; Kim, In S

2008-09-01

There is growing interest in the development of more cost-effective and retrofit technologies for the upgrade and expansion of existing wastewater treatment plants with extreme space constraints. A free-floating sponge media (BioCube) process, using a 24 L lab scale reactor, was operated to study the nitrification profiles and microbial community. The COD removal efficiencies were maintained, at an average of 95%, with the mixed liquor suspended solids (MLSS) inside the BioCube sponge media maintained at 12,688 mg/L. The nitrification removal efficiencies were between 92% and 100%, with an average value of 99%. From the results of microelectrode measurements, the ammonium ion concentration was found to rapidly decrease from the surface of the BioCube sponge media to a depth of 2mm due to chemical reactions carried out by ammonia oxidizing bacteria (AOB) species. Multi-fluorescence in situ hybridization (FISH) has been used to investigate the spatial distributions of various microbial activities within reactors. Microbial communities were targeted using different oligonucleotide probes specific to AOB and nitrite oxidizing bacteria (NOB). There were a large number of AOB populations, but these were not uniformly distributed in the biofilm compared to the NOB populations.

Transport of suspended matter through rock formations

International Nuclear Information System (INIS)

Wahlig, B.G.

1980-01-01

It may be hypothesized that significant quantities of some waste nuclides could be adsorbed on the surfaces of particles suspended in the flowing groundwater and thereby migrate farther or faster than they would in dissolved form. This thesis deals with one aspect of this proposed migration mechanism, the transport of suspended matter through rock formations. A theoretical examination of the forces effecting suspended particles in flowing groundwater indicates that only two interaction energies are likely to be significant compared to the particles' thermal energies. The responsible interactions are van der Waals attraction between the particles and the rock, and electrolytic double-layer repulsion between the atmospheres of ions near the surfaces of the particles and the rock. This theoretical understanding was tested in column flow adsorption experiments using fine kaolin particles as the suspended matter and crushed basalt as the rock medium. The effects of several parameters on kaolin mobility were explored, including the influences of the following: solution ion concentration, solution cation valence, degree of solution oxygen saturation, solution flow velocity, and degree of rock surface ageing. The experimental results indicate that the migration of suspended matter over kilometer distances in the lithosphere is very unlikely unless the average pore size of the conducting mediumis fairly large (> 1mm), or the flow occurs in large fractures

Effect of fermentation time of mixture of solid and liquid wastes from tapioca industry to percentage reduction of TSS (Total Suspended Solids)

Science.gov (United States)

Pandia, S.; Tanata, S.; Rachel, M.; Octiva, C.; Sialagan, N.

2018-02-01

The waste from tapioca industry is as an organic waste that contains many important compounds such as carbohydrate, protein, and glucose. This research as aimed to know the effect of fermentation time from solid waste combined with waste-water from the tapioca industry to percentage reduction of TSS. The study was started by mixing the solid and liquid wastes from tapioca industry at a ratio of 70:30, 60:40, 50:50, 40:60, and 30:70 (w/w) with a starter from solid waste of cattle in a batch anaerobic digester. The percentage reduction of TSS was 72.2289 at a ratio by weight of the composition of solid and liquid wastes from tapioca industry was 70:30 after 30 days of fermentation time.

Review of Oceanographic and Geochemical Data Collected in Massachusetts Bay during a Large Discharge of Total Suspended Solids from Boston's Sewage-Treatment System and Ocean Outfall in August 2002

Science.gov (United States)

Bothner, Michael H.; Butman, Bradford; Casso, Michael A.

2010-01-01

During the period August 14-23, 2002, the discharge of total suspended solids (TSS) from the Massachusetts Water Resources Authority sewage-treatment plant ranged from 32 to 132 milligrams per liter, causing the monthly average discharge to exceed the limit specified in the National Pollution Discharge Elimination System permit. Time-series monitoring data collected by the U.S. Geological Survey in western Massachusetts Bay were examined to evaluate changes in environmental conditions during and after this exceedance event. The rate of sediment trapping and the concentrations of near-bottom suspended sediment measured near the outfall in western Massachusetts Bay increased during this period. Because similar increases in sediment-trapping rate were observed in the summers of 2003 and 2004, however, the increase in 2002 cannot be definitively attributed to the increased TSS discharge. Concentrations of copper and silver in trapped sediment collected 10 and 20 days following the 2002 TSS event were elevated compared to those in pre-event samples. Maximum concentrations were less than 50 percent of toxicity guidelines. Photographs of surficial bottom sediments obtained before and after the TSS event do not show sediment accumulation on the sea floor. Concentrations of silver, Clostridium perfringens, and clay in surficial bottom sediments sampled 10 weeks after the discharge event at a depositional site 3 kilometers west of the outfall were unchanged from those in samples obtained before the event. Simulation of the TSS event by using a coupled hydrodynamic-wave-sediment-transport model could enhance understanding of these observations and of the effects of the exceedance on the local marine environment.

Use of biofilters and suspended-growth reactors to treat VOC's

Energy Technology Data Exchange (ETDEWEB)

Neal, A.B.; Loehr, R.C.

2000-07-01

The greater limits placed on volatile organic compound (VOC) emissions by the Clean Air Act Amendments have stimulated evaluation of various VOC treatment methods. Two applicable gas phase treatment technologies are biofiltration and suspended growth reactors. Biofiltration removes contaminants from gas streams that are passed through a bed of biologically active solids. An aerobic suspended-growth reactor (SGR) removes VOCs by biologically treating contaminated air bubbled through an aqueous suspension of active microorganisms. This research compared the performance of a typical compost biofilter to a SGR for the removal of a common VOC (toluene) from gas streams. The objective was to evaluate the impact of mass loading on process performance. Major performance parameters investigated were (1) mass emitted and elimination capacity, (2) off-gas concentrations exiting each type of reactor for various mass loadings, and (3) removal efficiencies obtained by each type of reactor. The results indicated that SGRs can effectively treat gases containing VOCs. For mass loadings ranging from 5 to 30 mg/l-h, the biofilters and SGRs achieved similar VOC removals, in the range of 96--99.7%. Drying of the biofilter medium occurred a high mass loadings. In the SGRs, at mass loadings greater than 17 mg/l-h, process performance decreased when an unknown colored substance was present.

Non-intrusive measurement and hydrodynamics characterization of gas–solid fluidized beds: a review

OpenAIRE

Sun, Jingyuan; Yan, Yong

2016-01-01

Gas-solid fluidization is a well-established technique to suspend or transport particles and has been applied in a variety of industrial processes. Nevertheless, our knowledge of fluidization hydrodynamics is still limited for the design, scale-up and operation optimization of fluidized bed reactors. It is therefore essential to characterize the two-phase flow behaviours in gas-solid fluidized beds and monitor the fluidization processes for control and optimization. A range of non-intrusive t...

The acoustic radiation force on a small thermoviscous or thermoelastic particle suspended in a viscous and heat-conducting fluid

Science.gov (United States)

Karlsen, Jonas; Bruus, Henrik

2015-11-01

We present a theoretical analysis (arxiv.org/abs/1507.01043) of the acoustic radiation force on a single small particle, either a thermoviscous fluid droplet or a thermoelastic solid particle, suspended in a viscous and heat-conducting fluid. Our analysis places no restrictions on the viscous and thermal boundary layer thicknesses relative to the particle radius, but it assumes the particle to be small in comparison to the acoustic wavelength. This is the limit relevant to scattering of ultrasound waves from sub-micrometer particles. For particle sizes smaller than the boundary layer widths, our theory leads to profound consequences for the acoustic radiation force. For example, for liquid droplets and solid particles suspended in gasses we predict forces orders of magnitude larger than expected from ideal-fluid theory. Moreover, for certain relevant choices of materials, we find a sign change in the acoustic radiation force on different-sized but otherwise identical particles. These findings lead to the concept of a particle-size-dependent acoustophoretic contrast factor, highly relevant to applications in acoustic levitation or separation of micro-particles in gases, as well as to handling of μm- and nm-sized particles such as bacteria and vira in lab-on-a-chip systems.

Design, analysis and control of cable-suspended parallel robots and its applications

CERN Document Server

Zi, Bin

2017-01-01

This book provides an essential overview of the authors’ work in the field of cable-suspended parallel robots, focusing on innovative design, mechanics, control, development and applications. It presents and analyzes several typical mechanical architectures of cable-suspended parallel robots in practical applications, including the feed cable-suspended structure for super antennae, hybrid-driven-based cable-suspended parallel robots, and cooperative cable parallel manipulators for multiple mobile cranes. It also addresses the fundamental mechanics of cable-suspended parallel robots on the basis of their typical applications, including the kinematics, dynamics and trajectory tracking control of the feed cable-suspended structure for super antennae. In addition it proposes a novel hybrid-driven-based cable-suspended parallel robot that uses integrated mechanism design methods to improve the performance of traditional cable-suspended parallel robots. A comparative study on error and performance indices of hybr...

Suspended sediment apportionment in a South-Korean mountain catchment

Science.gov (United States)

Birkholz, Axel; Meusburger, Katrin; Park, Ji-Hyung; Alewell, Christine

2016-04-01

Due to the rapid agricultural expansion and intensification during the last decades in South-Korea, large areas of hill slope forests were transformed to paddies and vegetable fields. The intensive agriculture and the easily erodible soils in our catchment are a major reason for the increased erosion causing suspended sediments to infiltrate into the close drinking water reservoir. The drinking water reservoir Lake Soyang provides water supply for over ten million people in Seoul. Landscape managers need to know the exact origin of these sediments before they can create landscape amelioration schemes. We applied a compound-specific stable isotope (CSSI) approach (Alewell et al., 2015) to apportion the sources of the suspended sediments between forest and agricultural soil contribution to the suspended sediments in a different catchment and applied the same approach to identify and quantify the different sources of the suspended sediments in the river(s) contributing to Lake Soyang. We sampled eight soil sites within the catchment considering the different landuse types forest, rice paddies, maize and vegetables. Suspended sediments were sampled at three outlets of the different sub-catchments. Soils and suspended sediments are analysed for bulk carbon and nitrogen isotopes, compound-specific carbon isotopes of plant-wax derived long-chain fatty acids and long-chain n-alkanes. Fatty acid and alkane isotopes are then used in mixing calculations and the mixing model software IsoSource to find out the contribution of the different source soils to the suspended sediments. We present first data of the source soils and the suspended sediments. C. Alewell, A. Birkholz, K. Meusburger, Y. Schindler-Wildhaber, L. Mabit, 2015. Sediment source attribution from multiple land use systems with CSIA. Biogeosciences Discuss. 12: 14245-14269.

Ultraclean individual suspended single-walled carbon nanotube field effect transistor

Science.gov (United States)

Liu, Siyu; Zhang, Jian; Nshimiyimana, Jean Pierre; Chi, Xiannian; Hu, Xiao; Wu, Pei; Liu, Jia; Wang, Gongtang; Sun, Lianfeng

2018-04-01

In this work, we report an effective technique of fabricating ultraclean individual suspended single-walled carbon nanotube (SWNT) transistors. The surface tension of molten silver is utilized to suspend an individual SWNT between a pair of Pd electrodes during annealing treatment. This approach avoids the usage and the residues of organic resist attached to SWNTs, resulting ultraclean SWNT devices. And the resistance per micrometer of suspended SWNTs is found to be smaller than that of non-suspended SWNTs, indicating the effect of the substrate on the electrical properties of SWNTs. The ON-state resistance (˜50 kΩ), mobility of 8600 cm2 V-1 s-1 and large on/off ratio (˜105) of semiconducting suspended SWNT devices indicate its advantages and potential applications.

Infrared Spectroscopy of Noh Suspended in Solid Parahydrogen: Part Two

Science.gov (United States)

Balabanoff, Morgan E.; Mutunga, Fredrick M.; Anderson, David T.

2015-06-01

The only report in the literature on the infrared spectroscopy of the parent oxynitrene NOH was performed using Ar matrix isolation spectroscopy at 10 K. In this previous study, they performed detailed isotopic studies to make definitive vibrational assignments. NOH is predicted by high-level calculations to be in a triplet ground electronic state, but the Ar matrix isolation spectra cannot be used to verify this triplet assignment. In our 2013 preliminary report, we showed that 193 nm in situ photolysis of NO trapped in solid parahydrogen can also be used to prepare the NOH molecule. Over the ensuing two years we have been studying the infrared spectroscopy of this species in more detail. The spectra reveal that NOH can undergo hindered rotation in solid parahydrogen such that we can observe both a-type and b-type rovibrational transitions for the O-H stretch vibrational mode, but only a-type for the mode assigned to the bend. In addition, both observed a-type infrared absorption features (bend and OH stretch) display fine structure; an intense central peak with weaker peaks spaced symmetrically to both lower and higher wavenumbers. The spacing between the peaks is nearly identical for both vibrational modes. We now believe this fine structure is due to spin-rotation interactions and we will present a detailed analysis of this fine structure. Currently, we are performing additional experiments aimed at making 15NOH to test these preliminary assignments. The most recent data and up-to-date analysis will be presented in this talk. G. Maier, H. P. Reisenauer, M. De Marco, Angew. Chem. Int. Ed. 38, 108-110 (1999). U. Bozkaya, J. M. Turney, Y. Yamaguchi, and H. F. Schaefer III, J. Chem. Phys. 136, 164303 (2012). David T. Anderson and Mahmut Ruzi, 68th Ohio State University International Symposium on Molecular Spectroscopy, talk TE01 (2013).

Energy values of suspended detritus in Andaman Sea

Digital Repository Service at National Institute of Oceanography (India)

Krishnakumari, L.; Royan, J.P.; Sumitra-Vijayaraghavan

Energy content of suspended detritus was determined in Andaman Sea waters during April-May 1988. The caloric content of suspended detritus ranged from 987 to 7040 cal. per gram dry wt with an average value of 5530 cal. per gram dry wt. The results...

Methods of and system for swing damping movement of suspended objects

Science.gov (United States)

Jones, J.F.; Petterson, B.J.; Strip, D.R.

1991-03-05

A payload suspended from a gantry is swing damped in accordance with a control algorithm based on the periodic motion of the suspended mass or by servoing on the forces induced by the suspended mass. 13 figures.

Solid phase transport in series fluidised bed reactors

International Nuclear Information System (INIS)

Hayes, M.R.

1980-01-01

In a multistage counter-current fluidised bed column, fluidised bed material is recycled within each stage and a fraction is continuously withdrawn to the next lower stage at a rate dependent only on the rate of removal of the fluidised bed material from the base of the column. It has a particular application to the ion exchange treatment of liquids containing suspended solids, for example leach solutions from uranium ores. (author)

The suspended sentence in French Criminal Law

Directory of Open Access Journals (Sweden)

Jovašević Dragan

2016-01-01

Full Text Available From the ancient times until today, criminal law has provided different criminal sanctions as measures of social control. These coercive measures are imposed on the criminal offender by the competent court and aimed at limitting the offender's rights and freedoms or depriving the offender of certain rights and freedoms. These sanctions are applied to the natural or legal persons who violate the norms of the legal order and injure or endanger other legal goods that enjoy legal protection. In order to effectively protect social values, criminal legislations in all countries predict a number of criminal sanctions. These are: 1 imprisonment, 2 precautions, 3 safety measures, 4 penalties for juveniles, and 5 sanctions for legal persons. Apart and instead of punishment, warning measures have a significant role in the jurisprudence. Since they emerged in the early 20th century in the system of criminal sanctions, there has been an increase in their application to criminal offenders, especially when it comes to first-time offenders who committed a negligent or accidental criminal act. Warnings are applied in case of crimes that do not have serious consequences, and whose perpetrators are not hardened and incorrigible criminals. All contemporary criminal legislations (including the French legilation provide a warning measure of suspended sentence. Suspended sentence is a conditional stay of execution of sentence of imprisonment for a specified time, provided that the convicted person does not commit another criminal offense and fulfills other obligations. This sanction applies if the following two conditions are fulfilled: a forma! -which is attached to the sentence of imprisonment; and b material -which is the court assessment that the application of this sanction is justified and necessary in a particular case. In many modern criminal legislations, there are two different types of suspended (conditional sentence: 1 ordinary (classical suspended

Quantification of Suspended Sediment Load by Double Correlation in the Watershed of Chellif (Algeria

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Bouchelkia Hamid

2014-07-01

Full Text Available The sediment transport in rivers in Algeria is very high. However, it is poorly quantified in some wadis because of the absence and the shortage of data especially the concentration of fine particles and also the unavailability of gauging stations. To fill this gap, a technique for estimating sediment yield, based on data recorded at the gauging station has been developed. The estimation of suspended sediment yield was conducted by a statistical analysis with double correlation on average daily flow and solid concentrations. The results obtained by applying this model to the watershed Chellif are very encouraging because the correlation coefficients of the found models are between 61% and 91% for the first correlation and between 86% and 97% for the second correlation. The estimated quantity of suspended sediment load is between 2.35 and 4.12 million tonnes per year, it appears important; This is due to the vulnerability of the Chellif basin facing erosion, the importance of its area and the importance of fluid flows in wadi Cheliff and its torrential regime. Mention here some of the results and their significance to the study.

On Suspended matter grain size in Baltic sea

Science.gov (United States)

Bubnova, Ekaterina; Sivkov, Vadim; Zubarevich, Victor

2016-04-01

Suspended matter grain size data were gathered during the 25th research vessel "Akademik Mstislav Keldysh" cruise (1991, September-October). Initial quantitative data were obtained with a use of the Coulter counter and subsequently modified into volume concentrations (mm3/l) for size intervals. More than 80 samples from 15 stations were analyzed (depth range 0-355 m). The main goal of research was to illustrate the spatial variability of suspended matter concentration and dispersion in Baltic Sea. The mutual feature of suspended matter grain size distribution is the logical rise of particle number along with descending of particle's size. Vertical variability of grain size distribution was defined by Baltic Sea hydrological structure, including upper mixed layer - from the surface to the thermocline - with 35 m thick, cold intermediate layer - from the thermocline to the halocline- and bottom layer, which lied under the halocline. Upper layer showed a rise in total suspended matter concentration (up to 0.6 mm3/l), while cold intermediate level consisted of far more clear water (up to 0.1 mm3/l). Such a difference is caused by the thermocline boarding role. Meanwhile, deep bottom water experienced surges in suspended matter concentration owing to the nepheloid layer presence and "liquid bottom" effect. Coastal waters appeared to have the highest amount of particles (up to 5.0 mm3/l). Suspended matter grain size distribution in the upper mixed layer revealed a peak of concentration at 7 μ, which can be due to autumn plankton bloom. Another feature in suspended matter grain size distribution appeared at the deep layer below halocline, where both O2 and H2S were observed and red/ox barrier is. The simultaneous presence of Fe and Mn (in solutions below red/ox barrier) and O2 leads to precipitation of oxyhydrates Fe and Mn and grain size distribution graph peaking at 4.5 μ.

Solid cellulose nanofiber based foams - Towards facile design of sustained drug delivery systems

DEFF Research Database (Denmark)

Svagan, Anna J; Benjamins, Jan-Willem; Al-Ansari, Zeinab

2016-01-01

acceptable surfactant (lauric acid sodium salt). The drug was suspended in the wet-stable foams followed by a drying step to obtain dry foams. Flexible cellular solid materials of different thicknesses, shapes and drug loadings (up to 50wt%) could successfully be prepared. The drug was released from...... the solid foams in a diffusion-controlled, sustained manner due to the presence of intact air bubbles which imparted a tortuous diffusion path. The diffusion coefficient was assessed using Franz cells and shown to be more than one order of magnitude lower for the cellular solids compared to the bubble...

Continuous-flow centrifugation to collect suspended sediment for chemical analysis

Science.gov (United States)

Conn, Kathleen E.; Dinicola, Richard S.; Black, Robert W.; Cox, Stephen E.; Sheibley, Richard W.; Foreman, James R.; Senter, Craig A.; Peterson, Norman T.

2016-12-22

Recent advances in suspended-sediment monitoring tools and surrogate technologies have greatly improved the ability to quantify suspended-sediment concentrations and to estimate daily, seasonal, and annual suspended-sediment fluxes from rivers to coastal waters. However, little is known about the chemical composition of suspended sediment, and how it may vary spatially between water bodies and temporally within a single system owing to climate, seasonality, land use, and other natural and anthropogenic drivers. Many water-quality contaminants, such as organic and inorganic chemicals, nutrients, and pathogens, preferentially partition in sediment rather than water. Suspended sediment-bound chemical concentrations may be undetected during analysis of unfiltered water samples, owing to small water sample volumes and analytical limitations. Quantification of suspended sediment‑bound chemical concentrations is needed to improve estimates of total chemical concentrations, chemical fluxes, and exposure levels of aquatic organisms and humans in receiving environments. Despite these needs, few studies or monitoring programs measure the chemical composition of suspended sediment, largely owing to the difficulty in consistently obtaining samples of sufficient quality and quantity for laboratory analysis.A field protocol is described here utilizing continuous‑flow centrifugation for the collection of suspended sediment for chemical analysis. The centrifuge used for development of this method is small, lightweight, and portable for the field applications described in this protocol. Project scoping considerations, deployment of equipment and system layout options, and results from various field and laboratory quality control experiments are described. The testing confirmed the applicability of the protocol for the determination of many inorganic and organic chemicals sorbed on suspended sediment, including metals, pesticides, polycyclic aromatic hydrocarbons, and

Measurements of Two-Phase Suspended Sediment Transport in Breaking Waves Using Volumetric Three-Component Velocimetry

Science.gov (United States)

Ting, F. C. K.; LeClaire, P.

2016-02-01

Understanding the mechanisms of sediment pickup and distribution in breaking waves is important for modeling sediment transport in the surf zone. Previous studies were mostly concerned with bulk sediment transport under specific wave conditions. The distribution of suspended sediments in breaking waves had not been measured together with coherent flow structures. In this study, two-phase flow measurements were obtained under a train of plunging regular waves on a plane slope using the volumetric three-component velocimetry (V3V) technique. The measurements captured the motions of sediment particles simultaneously with the three-component, three-dimensional (3C3D) velocity fields of turbulent coherent structures (large eddies) induced by breaking waves. Sediment particles (solid glass spheres diameter 0.125 to 0.15 mm, specific gravity 2.5) were separated from fluid tracers (mean diameter 13 µm, specific gravity 1.3) based on a combination of particle spot size and brightness in the two-phase images. The interactions between the large eddies and glass spheres were investigated for plunger vortices generated at incipient breaking and for splash-up vortices generated at the second plunge point. The measured data show that large eddies impinging on the bottom was the primary mechanism which lift sediment particles into suspension and momentarily increased near-bed suspended sediment concentration. Although eddy impingement events were sporadic in space and time, the distributions of suspended sediments in the large eddies were not uniform. High suspended sediment concentration and vertical sediment flux were found in the wall-jet region where the impinging flow was deflected outward and upward. Sediment particles were also trapped and carried around by counter-rotating vortices (Figure 1). Suspended sediment concentration was significantly lower in the impingement region where the fluid velocity was downward, even though turbulent kinetic energy in the down flow was

Spatiotemporal dynamics of suspended sediment within an actively urbanizing peri-urban catchment in Portugal

Science.gov (United States)

Walsh, Rory; Ferreira, Carla; Ferreira, Antonio

2016-04-01

Suspended sediment levels tend to be enhanced in urban catchments, but vary considerably with (amongst many other factors) the degree of active urban development or redevelopment within the catchment and 'urbanization style'. Relatively little, however, is known about the relationship between suspended solids and urbanization style in peri-urban Mediterranean environments. This paper focuses on spatiotemporal suspended sediment dynamics within a typical Portuguese peri-urban catchment, Ribeira dos Covoes, that is undergoing rapid urbanization. The catchment currently has a 40% urban cover, with 17% impervious surfaces, dispersed between woodland (56%) and agricultural areas (4%). The study uses suspended sediment concentration measurements made at the catchment outlet (ESAC) and in three upstream tributaries: (i) Espírito Santo, with a largest urban area (49%); (ii) Porto Bordalo, 39% urbanized; and (iii) Quinta, 22% urbanized, most of which (18%) being an enterprise park under construction. Water sampling was carried out manually during 10 storm hydrographs between October 2011 and March 2013. Suspended sediment concentrations (SSC) were derived by laboratory analysis of the filtered samples using the gravimetric method. In addition total dissolved solids concentrations (TDS) were estimated using conductivity readings. Greatest SSCs were recorded in the Quinta sub-catchment and at the catchment outlet at ESAC (113-4320 mg L-1 and 200-1656 mg L-1, respectively) than in the Espírito Santo and Porto Bordalo sub-catchments (183-852 mg L-1 and 47-598 mg L-1 respectively, despite their greater impervious cover. The greatest SSCs for Quinta result from it containing the construction site, but it showed lower TDS (56-4010 mg L-1), perhaps due to the coarse sandy nature of the construction site. Higher TDS concentrations, however, were displayed in Porto Bordalo (27-5400 mg L-1), possibly due to the loamy soil. Espírito Santo, comprising sandy-loam soils, displayed 27

Motion of a suspended charged particle in a NON-Newtonian fluid. Vol. 2

Energy Technology Data Exchange (ETDEWEB)

Abdel-Khalek, M M [Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

The path lines of a solid spherical charged particle suspended in a non-newton electrical conducting viscous fluid through two infinite parallel plates in the presence of a constant magnetic field normal to the plane of particle motion were determined. The effect of some parameters such as particle volume, fluid density, fluid viscosity, and the use magnetic field strength on these path lines were determined. The present solution requires some empirical parameters concerning the collision of the particles with the wall. The differential equations of motion were numerically solved by Runge-Kutta method. Some conclusions about width, maximum height and number of collisions with upper and lower plates were deduced. 4 figs.

Dynamic model of movement of mine suspended monorail

Directory of Open Access Journals (Sweden)

Viktor GUTAREVYCH

2014-03-01

Full Text Available In the article we have developed the dynamic model of interaction of rolling stock during the movement, on the suspended monorail, taking into account the side-sway. We have received the motion equations, carried out their analysis and determined the own oscillation frequencies of rolling stock of suspended monorail.

Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

Energy Technology Data Exchange (ETDEWEB)

Solak, Murat [Duezce University, Kaynasli Vocational School, Environmental Protection and Control Department, 81900 Duezce (Turkey); Kilic, Mehmet, E-mail: kavi@mmf.sdu.edu.tr [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey); Hueseyin, Yazici; Sencan, Aziz [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey)

2009-12-15

In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m{sup 2}, and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m{sup 2}, respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

International Nuclear Information System (INIS)

Solak, Murat; Kilic, Mehmet; Hueseyin, Yazici; Sencan, Aziz

2009-01-01

In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m 2 , and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m 2 , respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: comparison of electrode materials and electrode connection systems.

Science.gov (United States)

Solak, Murat; Kiliç, Mehmet; Hüseyin, Yazici; Sencan, Aziz

2009-12-15

In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m(2), and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m(2), respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

Biogas production from organic wastes in suspended cell cultures and in biofilms

International Nuclear Information System (INIS)

Simenonov, I.; Chorukova, E.; Mamatarkova, V.; Nikolov, L.

2010-01-01

The results of a comparative study of two biogas production bioprocess systems are presented. The systems submitted to comparison are based on the suspended cells cultures and the biofilm formed on solid inert support. A comprehensive research concept is formulated and discussed. It includes the main considerations regarding the choice of substrate, bioagent as mixed microbial society, type of bioreactors, regimes of functioning, analytical determinations and method of comparison. The main requirements for efficient experimental activity in comparative investigations are formulated. Their satisfaction can grant correctness of the experimental design and data acquisition. On this basis the key parameter of comparison of the two systems is defined as the specific productivity of the bioprocess systems. Under these conditions series of preliminary experiments are carried out for testing the readiness of experimental set ups for long time stable functioning and monitoring devices capabilities to maintain the bioprocess parameters at the determined intervals. These tests grant continuous incessant experimentation with the investigated bioprocess systems. The results obtained show that biofilm bioprocess systems possess up to two and half time higher specific productivity in comparison with the bioprocess systems with the suspended cells. Some visions about the future developments of comparative research on the influence of additional parameters like the mixer rotation steed, organic loads, and higher values of dilution rates are outlined.

Determination of the origin of suspended matter and sediments in the Elbe estuary using natural tracers

International Nuclear Information System (INIS)

Schoer, J.H.

1990-01-01

The clay mineral composition, the concentrations of carbonates, the proportions of carbon and oxygen isotopes in carbonates and organic matter, as well as the concentrations of different nonanthropogenic metals were used to determine the origin of different grain size fractions of sediments and suspended matter in the Elbe estuary. Analysis of the smectite/kaolinite proportion revealed that solid material · 2 μm from the North Sea is transported up the river, about 40 km beyond the most upstream position of the salt wedge. In the 2-20 μm fraction, the 16 O/ 18 O ratio in carbonates and the kaolinite/chlorite proportion demonstrate a transport of North Sea material between 40 and 20 km upstream of the marine water limit. The transport behavior of the 20-63 μm grain size fraction could be determined by the hafnium concentration, representative for the heavy mineral zircon. In this case, the transport distance beyond the salt wedge was up to 20 km. No information was available on the origin of the fine organic matter, whereas the coarser fractions were derived primarily from debris of salt marsh vegetation. The results demonstrate that in the Elbe estuary mixing between marine and fluvial solid material occurs upstream of the salt wedge and is significantly responsible for the observed decrease in the concentration of various pollutants in sediments and suspended matter along the estuary. The cause of the upstream particle transport is probably a scour lag mechanism based on asymmetries of the flood- and ebb-tide current distribution, especially their differing maximum velocities

Numerical Simulation of Flow and Suspended Sediment Transport in the Distributary Channel Networks

Directory of Open Access Journals (Sweden)

Wei Zhang

2014-01-01

Full Text Available Flow and suspended sediment transport in distributary channel networks play an important role in the evolution of deltas and estuaries, as well as the coastal environment. In this study, a 1D flow and suspended sediment transport model is presented to simulate the hydrodynamics and suspended sediment transport in the distributary channel networks. The governing equations for river flow are the Saint-Venant equations and for suspended sediment transport are the nonequilibrium transport equations. The procedure of solving the governing equations is firstly to get the matrix form of the water level and suspended sediment concentration at all connected junctions by utilizing the transformation of the governing equations of the single channel. Secondly, the water level and suspended sediment concentration at all junctions can be obtained by solving these irregular spare matrix equations. Finally, the water level, discharge, and suspended sediment concentration at each river section can be calculated. The presented 1D flow and suspended sediment transport model has been applied to the Pearl River networks and can reproduce water levels, discharges, and suspended sediment concentration with good accuracy, indicating this that model can be used to simulate the hydrodynamics and suspended sediment concentration in the distributary channel networks.

Field Emission of Wet Transferred Suspended Graphene Fabricated on Interdigitated Electrodes.

Science.gov (United States)

Xu, Ji; Wang, Qilong; Tao, Zhi; Qi, Zhiyang; Zhai, Yusheng; Wu, Shengqi; Zhang, Xiaobing; Lei, Wei

2016-02-10

Suspended graphene (SG) membranes could enable strain-engineering of ballistic Dirac fermion transport and eliminate the extrinsic bulk disorder by annealing. When freely suspended without contact to any substrates, graphene could be considered as the ultimate two-dimensional (2D) morphology, leading to special field characteristics with the 2D geometrical effect and effectively utilized as an outstanding structure to explore the fundamental electronic or optoelectronic mechanism. In this paper, we report field emission characterization on an individual suspended few-layer graphene. A controllable wet transfer method is used to obtain the continuous and suspended graphene membrane on interdigitated gold electrodes. This suspended structure displays an overall field emission from the entirely surface, except for the variation in the emitting positions, acquiring a better enhancement than the exfoliated graphene on the conventional flat substrate. We also observe the transition process from space charge flow at low bias to the Fowler-Nordheim theory at high current emission regime. It could enable theoretical and experimental investigation of the typical electron emission properties of the 2D regime. Numerical simulations are also carried out to study the electrical properties of the suspended structure. Further improvement on the fabrication would realize low disorder, high quality, and large-scale suspended graphene devices.

76 FR 49449 - Continuation of Antidumping Duty Order on Solid Fertilizer Grade Ammonium Nitrate From the...

Science.gov (United States)

2011-08-10

... nitrate (``ammonium nitrate'') from the Russian Federation (``Russia'') would likely lead to continuation... Duty Order on Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation AGENCY: Import... ammonium nitrate suspended investigation. See Initiation of Five-Year (``Sunset'') Review, 76 FR 11202...

Electron stimulated reactions of methyl iodide coadsorbed with amorphous solid water

International Nuclear Information System (INIS)

Perry, C. C.; Faradzhev, N. S.; Madey, T. E.; Fairbrother, D. H.

2007-01-01

The electron stimulated reactions of methyl iodide (MeI) adsorbed on and suspended within amorphous solid water (ice) were studied using a combination of postirradiation temperature programmed desorption and reflection absorption infrared spectroscopy. For MeI adsorbed on top of amorphous solid water (ice), electron beam irradiation is responsible for both structural and chemical transformations within the overlayer. Electron stimulated reactions of MeI result principally in the formation of methyl radicals and solvated iodide anions. The cross section for electron stimulated decomposition of MeI is comparable to the gas phase value and is only weakly dependent upon the local environment. For both adsorbed MeI and suspended MeI, reactions of methyl radicals within MeI clusters lead to the formation of ethane, ethyl iodide, and diiodomethane. In contrast, reactions between the products of methyl iodide and water dissociation are responsible for the formation of methanol and carbon dioxide. Methane, formed as a result of reactions between methyl radicals and either parent MeI molecules or hydrogen atoms, is also observed. The product distribution is found to depend on the film's initial chemical composition as well as the electron fluence. Results from this study highlight the similarities in the carbon-containing products formed when monohalomethanes coadsorbed with amorphous solid water are irradiated by either electrons or photons

Elemental compositions of suspended particles released in glass manufacture

Energy Technology Data Exchange (ETDEWEB)

Mamuro, T; Mizohata, A; Kubota, T [Radiation Center of Osaka Prefecture, Sakai (Japan)

1980-03-01

Suspended particles released in glass manufacture were subjected to multielement analysis by means of instrumental neutron activation method and energy dispersive X-ray fluorescence spectrometry. Suspended particles emitted from glass manufacture generally consist of both particles emitted from glass fusion and those produced through fuel combustion (mainly oil combustion). Elemental compositions of suspended particles emitted from glass fusion were found to be strongly dependent on the kind and recipe of raw materials and additives. Of the various metallic elements involved in suspended particles emitted from glass fusion, the elements, As, Se, Cd, Sb, Pb and so on are regarded to produce the most serious air pollution. The amount of emission of these elements to the environment is, howerer, quite varied from manufacturer to manufacturer. The replacement of electric furnace by oil combustion in opal glass manufacture remarkably reduced the emission of metallic elements to the environment.

Pesticides in Water and Suspended Sediment of the Alamo and New Rivers, Imperial Valley/Salton Sea Basin, California, 2006-2007

Science.gov (United States)

Orlando, James L.; Smalling, Kelly L.; Kuivila, Kathryn

2008-01-01

Water and suspended-sediment samples were collected at eight sites on the Alamo and New Rivers in the Imperial Valley/Salton Sea Basin of California and analyzed for both current-use and organochlorine pesticides by the U.S. Geological Survey. Samples were collected in the fall of 2006 and spring of 2007, corresponding to the seasons of greatest pesticide use in the basin. Large-volume water samples (up to 650 liters) were collected at each site and processed using a flow-through centrifuge to isolate suspended sediments. One-liter water samples were collected from the effluent of the centrifuge for the analysis of dissolved pesticides. Additional samples were collected for analysis of dissolved organic carbon and for suspended-sediment concentrations. Water samples were analyzed for a suite of 61 current-use and organochlorine pesticides using gas chromatography/mass spectrometry. A total of 25 pesticides were detected in the water samples, with seven pesticides detected in more than half of the samples. Dissolved concentrations of pesticides observed in this study ranged from below their respective method detection limits to 8,940 nanograms per liter (EPTC). The most frequently detected compounds in the water samples were chlorpyrifos, DCPA, EPTC, and trifluralin, which were observed in more than 75 percent of the samples. The maximum concentrations of most pesticides were detected in samples from the Alamo River. Maximum dissolved concentrations of carbofuran, chlorpyrifos, diazinon, and malathion exceeded aquatic life benchmarks established by the U.S. Environmental Protection Agency for these pesticides. Suspended sediments were analyzed for 87 current-use and organochlorine pesticides using microwave-assisted extraction, gel permeation chromatography for sulfur removal, and either carbon/alumina stacked solid-phase extraction cartridges or deactivated Florisil for removal of matrix interferences. Twenty current-use pesticides were detected in the suspended

The rheology of non-suspended sediment transport mediated by a Newtonian fluid

Science.gov (United States)

Pähtz, Thomas; Durán, Orencio

2017-04-01

Using a coupled DEM/RANS numerical model of non-suspended sediment transport in a Newtonian fluid (Durán et al., POF 103306, 2012), we find that the gas-like part of the granular transport flow can be described by a universal condition that constrains the average geometry of interparticle collisions. We show that this condition corresponds to a constant sliding friction coefficient μ at an appropriately defined bed surface, thus explaining the success of Bagnold's old idea to describe the sediment transport in analogy to sliding friction. We are currently exploring whether this rheology applies to gas-like granular flows in general. We further find a transition of the gas-like flow to either a solid-like flow (solid-to-gas transition), which is typical for aeolian sediment transport ('saltation'), or a liquid-like flow (liquid-to-gas transition), which is typical for subaqueous sediment transport ('bedload'). The transition occurs at about the location of maximal particle collision frequency. If there is a liquid-like flow below the transition, we find that it can be described by a μ(I) rheology, where I is the visco-intertial number, an appropriately defined average of the viscous and intertial number.

Molybdenum-rhenium superconducting suspended nanostructures

Energy Technology Data Exchange (ETDEWEB)

Aziz, Mohsin; Christopher Hudson, David; Russo, Saverio [Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF (United Kingdom)

2014-06-09

Suspended superconducting nanostructures of MoRe 50%/50% by weight are fabricated employing commonly used fabrication steps in micro- and nano-meter scale devices followed by wet-etching with Hydro-fluoric acid of a SiO{sub 2} sacrificial layer. Suspended superconducting channels as narrow as 50 nm and length 3 μm have a critical temperature of ≈6.5 K, which can increase by 0.5 K upon annealing at 400 °C. A detailed study of the dependence of the superconducting critical current and critical temperature upon annealing and in devices with different channel widths reveals that desorption of contaminants is responsible for the improved superconducting properties. These findings pave the way for the development of superconducting electromechanical devices using standard fabrication techniques.

Fluid-solid boundary conditions for multiparticle collision dynamics

International Nuclear Information System (INIS)

Whitmer, Jonathan K; Luijten, Erik

2010-01-01

The simulation of colloidal particles suspended in solvent requires an accurate representation of the interactions between the colloids and the solvent molecules. Using the multiparticle collision dynamics method, we examine several proposals for stick boundary conditions, studying their properties in both plane Poiseuille flow (where fluid interacts with the boundary of a stationary macroscopic solid) and particle-based colloid simulations (where the boundaries are thermally affected and in motion). In addition, our simulations compare various collision rules designed to remove spurious slip near solid surfaces, and the effects of these rules on the thermal motion of colloidal particles. Furthermore, we demonstrate that stochastic reflection of the fluid at solid boundaries fails to faithfully represent stick boundary conditions, and conclude that bounce-back conditions should be applied at both mobile and stationary surfaces. Finally, we generalize these ideas to create partial slip boundary conditions at both stationary and mobile surfaces.

Suspended sediment in a high-Arctic river

DEFF Research Database (Denmark)

Ladegaard-Pedersen, Pernille; Sigsgaard, Charlotte; Kroon, Aart

2017-01-01

-2012) of daily measurements from the high-Artic Zackenberg River in Northeast Greenland to estimate annual suspended sediment fluxes based on four commonly used methods: M1) is the discharge weighted mean and uses direct measurements, while M2-M4) are one uncorrected and two bias corrected rating curves......-1 and 61,000±16,000ty-1. Extreme events with high discharges had a mean duration of 1day. The average suspended sediment flux during extreme events was 17,000±5000ty-1, which constitutes a year-to-year variation of 20-37% of the total annual flux. The most accurate sampling strategy was bi...... extrapolating a continuous concentration trace from measured values. All methods are tested on complete and reduced datasets. The average annual runoff in the period 2005-2012 was 190±25mio·m3 y-1. The different estimation methods gave a range of average annual suspended sediment fluxes between 43,000±10,000ty...

A novel fabrication method for suspended high-aspect-ratio microstructures

Science.gov (United States)

Yang, Yao-Joe; Kuo, Wen-Cheng

2005-11-01

Suspended high-aspect-ratio structures (suspended HARS) are widely used for MEMS devices such as micro-gyroscopes, micro-accelerometers, optical switches and so on. Various fabrication methods, such as SOI, SCREAM, AIM, SBM and BELST processes, were proposed to fabricate HARS. However, these methods focus on the fabrication of suspended microstructures with relatively small widths of trench opening (e.g. less than 10 µm). In this paper, we propose a novel process for fabricating very high-aspect-ratio suspended structures with large widths of trench opening using photoresist as an etching mask. By enhancing the microtrenching effect, we can easily release the suspended structure without thoroughly removing the floor polymer inside the trenches for the cases with a relatively small trench aspect ratio. All the process steps can be integrated into a single-run single-mask ICP-RIE process, which effectively reduces the process complexity and fabrication cost. We also discuss the phenomenon of corner erosion, which results in the undesired etching of silicon structures during the structure-releasing step. By using the proposed process, 100 µm thick suspended structures with the trench aspect ratio of about 20 are demonstrated. Also, the proposed process can be used to fabricate devices for applications which require large in-plane displacement. This paper was orally presented in the Transducers'05, Seoul, Korea (paper ID: 3B1.3).

Laboratory study on the adsorption of Mn(2+) on suspended and deposited amorphous Al(OH)(3) in drinking water distribution systems.

Science.gov (United States)

Wang, Wendong; Zhang, Xiaoni; Wang, Hongping; Wang, Xiaochang; Zhou, Lichuan; Liu, Rui; Liang, Yuting

2012-09-01

Manganese (II) is commonly present in drinking water. This paper mainly focuses on the adsorption of manganese on suspended and deposited amorphous Al(OH)(3) solids. The effects of water flow rate and water quality parameters, including solution pH and the concentrations of Mn(2+), humic acid, and co-existing cations on adsorption were investigated. It was found that chemical adsorption mainly took place in drinking water with pHs above 7.5; suspended Al(OH)(3) showed strong adsorption capacity for Mn(2+). When the total Mn(2+) input was 3 mg/L, 1.0 g solid could accumulate approximately 24.0 mg of Mn(2+) at 15 °C. In drinking water with pHs below 7.5, because of H(+) inhibition, active reaction sites on amorphous Al(OH)(3) surface were much less. The adsorption of Mn(2+) on Al(OH)(3) changed gradually from chemical coordination to physical adsorption. In drinking water with high concentrations of Ca(2+), Mg(2+), Fe(3+), and HA, the removal of Mn(2+) was enhanced due to the effects of co-precipitation and adsorption. In solution with 1.0 mg/L HA, the residual concentration of Mn(2+) was below 0.005 mg/L, much lower than the limit value required by the Chinese Standard for Drinking Water Quality. Unlike suspended Al(OH)(3), deposited Al(OH)(3) had a much lower adsorption capacity of 0.85 mg/g, and the variation in flow rate and major water quality parameters had little effect on it. Improved managements of water age, pipe flushing and mechanical cleaning were suggested to control residual Mn(2+). Copyright © 2012 Elsevier Ltd. All rights reserved.

Numerical Simulations of the Impact and Spreading of a Particulate Drop on a Solid Substrate

Directory of Open Access Journals (Sweden)

Hyun Jun Jeong

2012-01-01

Full Text Available We present two-dimensional numerical simulations of the impact and spreading of a droplet containing a number of small particles on a flat solid surface, just after hitting the solid surface, to understand particle effects on spreading dynamics of a particle-laden droplet for the application to the industrial inkjet printing process. The Navier-Stokes equation is solved by a finite-element-based computational scheme that employs the level-set method for the accurate interface description between the drop fluid and air and a fictitious domain method for suspended particles to account for full hydrodynamic interaction. Focusing on the particle effect on droplet spreading and recoil behaviors, we report that suspended particles suppress the droplet oscillation and deformation, by investigating the drop deformations for various Reynolds numbers. This suppressed oscillatory behavior of the particulate droplet has been interpreted with the enhanced energy dissipation due to the presence of particles.

Suspended particle dynamics and fluxes in an Arctic fjord (Kongsfjorden, Svalbard)

Science.gov (United States)

Meslard, Florian; Bourrin, François; Many, Gaël; Kerhervé, Philippe

2018-05-01

An experiment was carried out during summer 2015 in the inner part of the Kongsfjorden to study the inputs of meltwater and behaviour of associated suspended particles. We used a wide range of oceanographic instruments to assess the hydrological and hydrodynamic characteristics of coastal waters. The transfer of suspended particles occurs from a large surface plume fed by two main sources: the most important one is the upwelling of fresh and turbid water coming from a tide-water glacier: the Kronebreen, and the second one from a continental glacier: the Kongsvegen. We estimated that these two sources discharged about 2.48 ± 0.37 × 106 t of suspended sediments during the two months of melting. The major part of these sediments is deposited within the first kilometre due to flocculation phenomena. Flocculation is initiated below the surface turbid plume and is mainly caused by the salinity gradient and high suspended particle concentration. Finally, our estimates of suspended particle fluxes by a typical Arctic coastal glacier showed the need to consider suspended sediment fluxes from high-latitude areas into global budgets in the context of climate change.

High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer

Energy Technology Data Exchange (ETDEWEB)

Campbell, Chris G.; Laycak, Danny T.; Hoppes, William; Tran,Nguyen T.; Shi, Frank G.

2004-05-26

Suspended sediment loads mobilized during high flow periods in rivers and streams are largely uncharacterized. In smaller and intermittent streams, a large storm may transport a majority of the annual sediment budget. Therefore monitoring techniques that can measure high suspended sediment concentrations at semi-continuous time intervals are needed. A Fiber optic In-stream Transmissometer (FIT) is presented for continuous measurement of high concentration suspended sediment in storm runoff. FIT performance and precision were demonstrated to be reasonably good for suspended sediment concentrations up to 10g/L. The FIT was compared to two commercially available turbidity devices and provided better precision and accuracy at both high and low concentrations. Both turbidity devices were unable to collect measurements at concentrations greater than 4 g/L. The FIT and turbidity measurements were sensitive to sediment particle size. Particle size dependence of transmittance and turbidity measurement poses the greatest problem for calibration to suspended sediment concentration. While the FIT was demonstrated to provide acceptable measurements of high suspended sediment concentrations, approaches to real-time suspended sediment detection need to address the particle size dependence in concentration measurements.

Remote sensing of suspended sediment water research: principles, methods, and progress

Science.gov (United States)

Shen, Ping; Zhang, Jing

2011-12-01

In this paper, we reviewed the principle, data, methods and steps in suspended sediment research by using remote sensing, summed up some representative models and methods, and analyzes the deficiencies of existing methods. Combined with the recent progress of remote sensing theory and application in water suspended sediment research, we introduced in some data processing methods such as atmospheric correction method, adjacent effect correction, and some intelligence algorithms such as neural networks, genetic algorithms, support vector machines into the suspended sediment inversion research, combined with other geographic information, based on Bayesian theory, we improved the suspended sediment inversion precision, and aim to give references to the related researchers.

Removal of nitrogen and organic matter in a submerged-membrane bioreactor operating in a condition of simultaneous nitrification and denitrification

Directory of Open Access Journals (Sweden)

Izabela Major Barbosa

2016-04-01

Full Text Available This study evaluated the removal of nitrogen and organic matter in a membrane bioreactor system operating in a condition of simultaneous nitrification and denitrification controlled by intermittent aeration. A submerged-membrane system in a bioreactor was used in a pilot scale to treat domestic wastewater. The dissolved oxygen concentration was maintained between 0.5 and 0.8 mg L-1. The concentration of the mixed liquor suspended solids (MLSS in the system ranged from 1 to 6 g L-1. The system efficiency was evaluated by the removal efficiency of organic matter, quantified by Chemical Oxygen Demand (COD, Biochemical Oxygen Demand (BOD5 and Total Organic Carbon (TOC. Nitrogen removal was assessed by quantifying Total Kjeldahl Nitrogen (TKN and ammonia nitrogen. During the system start-up, the removal efficiencies of COD and NTK were around 90% and 80%, respectively. After the simultaneous nitrification and denitrification (SND conditions were established, the removal efficiencies of COD and NTK were 70% and 99%, respectively. These results showed that sewage treatment with the membrane bioreactor (MBR system, operating with simultaneous nitrification and denitrification conditions, was able to remove organic matter and promote nitrification and denitrification in a single reactor, producing a high-quality permeate.

Source Apportionment of Suspended Sediment Sources using 137Cs and 210Pbxs

Science.gov (United States)

Lamba, J.; Karthikeyan, K.; Thompson, A.

2017-12-01

A study was conducted in the Pleasant Valley Watershed (50 km 2) in South Central Wisconsin to better understand sediment transport processes using sediment fingerprinting technique. Previous studies conducted in this watershed showed that resuspension of fine sediment deposited on the stream bed is an important source of suspended sediment. To better understand the role of fine sediment deposited on the stream bed, fallout radionuclides,137Cs and 210Pbxs were used to determine relative contribution to suspended sediment from in-stream (stream bank and stream bed) and upland sediment sources. Suspended sediment samples were collected during the crop growing season. Potential sources of suspended sediment considered in this study included cropland, pasture and in-stream (stream bed and stream bank). Suspended sediment sources were determined at a subwatershed level. Results of this study showed that in-stream sediment sources are important sources of suspended sediment. Future research should be conducted to better understand the role of legacy sediment in watershed-level sediment transport processes.

Reconstruction of the solid transport of the river Tiber by a stochastic model

International Nuclear Information System (INIS)

Grimaldi, S.; Magnaldi, S.; Margaritora, G.

1999-01-01

The chronological series of cumulative suspended solids transport observed at Ripetta station in river Tiber (Rome, Italy) is reconstructed on the base of the correlation with the chronological series of liquid discharge, using a TFN (Transfer Function Noise) stochastic model with SARIMA noise. The results are compared with those similar reconstructions based on linear correlation that can be found in literature. Finally, the importance of floods intensity and frequency decrease observed after 1950 at Ripetta station is shown as not negligible aggravation for the decrease solid transport in river Tiber [it

76 FR 39847 - Solid Fertilizer Grade Ammonium Nitrate From the Russian Federation; Final Results of the...

Science.gov (United States)

2011-07-07

... duty order on ammonium nitrate from Russia would be likely to lead to continuation or recurrence of... Ammonium Nitrate From the Russian Federation; Final Results of the Expedited Sunset Review of Antidumping... review of the suspended antidumping duty investigation on solid fertilizer grade ammonium nitrate...

Status of Suspended Particulate Matters Pollution at Traditional Markets in Makassar City

Science.gov (United States)

Suryani, Sri; Fahrunnisa

2018-03-01

Research on the status of suspended particulate matters pollution in four traditional markets located in Makassar city has been done. The purpose of this research is to know the air quality in the traditional market areas, especially caused by suspended particulate matters. The background of this research is because traders who trade in traditional markets generally peddle their goods along dusty roads and suspended particulate matters in dust can be inhaled when the vehicle passes. These suspended particulate matters pollutant can cause lung diseases. The results showed that the level of suspended particulate matters pollution fluctuates every year depending on the local wind speed, humidity, and temperature. Research results also showed the values were over the standard value according to the governor of South Sulawesi regulation.

The suspended sentence in German criminal law

Directory of Open Access Journals (Sweden)

Jovašević Dragan

2017-01-01

Full Text Available From the ancient times until today, criminal law in all countries has provided different criminal sanctions as social control measures. These are court-imposed coercive measures that take away or limit certain rights and freedoms of criminal offenders. Sanctions are applied to natural or legal persons who violate the norms of the legal order and cause damage or endanger other legal goods that enjoy legal protection. In order to effectively protect social values jeopardized by the commission of crime, state legislations prescribe several kinds of criminal sanctions: 1 penalties, 2 precautions, 3 safety measures, 4 penalties for juvenile offenders, and 5 sanctions for legal persons. Penalties are the basic, the oldest and the most important type of criminal sanctions. They are prescribed for the largest number of criminal offences. Imposed instead of or alongside with penalties, warning measures have particularly important role in jurisprudence. Since they were introduced in the system of criminal sanctions in the early 20th century, there has been a notable increase in the application of these measures, particularly in cases involving negligent and accidental offences, and minor offences that do not cause serious consequences, whose perpetrators are not persons with criminal characteristics. Warning measures (suspended sentence are envisaged in all contemporary criminal legislations, including the German legislation. Suspended sentence is a conditional stay of execution of the sentence of imprisonment for a specified time, provided that the convicted person fulfills the imposed obligations and does not commit another criminal offense. Two conditions must be fulfilled for the application of these sanctions: a the formal requirement, which is attached to the sentence of imprisonment; and b the substantive requirement, which implies the court assessment that the application of these sanctions is justified and necessary in a particular case. Many

Magnetically suspended experimental vehicle-strength of structure and dynamic analysis

Energy Technology Data Exchange (ETDEWEB)

Nagahiro, T; Terada, K; Kasai, Y; Motonaga, M

1973-06-01

To cope with rapid increase in demand for railroad transportation, studies in magnetically suspended high speed trains are being pushed forward at the Japanese National Railways. Recently a special experimental vehiclc was completed which will be used by JNR in experiments concerning magnetic propulsion and suspension of magnetically suspended high speed trains. This test vehicle is provided with reaction plates of linear induction motor under the floor at about the center of the vehicle, with superconducting magnets for suspension on both sides. The vehicle body is made mainly of high tensile strengthened aluminium (duralumin) for weight reduction, but its strength was checked by the vibration analysis and load tests carried out in the suspended condition. Remote-operated from the control tower, this unmanned test vehicle will provide a key to the completion of a super-high speed magnetically suspended train.

Gas Generation from Solids in Aqueous Suspensions

International Nuclear Information System (INIS)

Meisel, D.; Schatz, T.

1999-01-01

The presence of solid particles suspended in solution may change the radiation-induced chemistry of a system in many ways. Catalytic surface effects may manifest themselves through the acceleration or inhibition of various reactions. As importantly, the yield of primary radiolysis products may be affected as the solids absorb a significant fraction of the radiation energy. The latter is the subject of this study. We explore the possibility that absorption of radiation by the solid particles may initiate chemistry in the water. This is a question of fundamental as well as practical significance. On the fundamental side we ask whether electron-hole pairs generated in the solid phase can escape and cross into the aqueous phase and initiate chemical reactions such as gas generation and how this possibility depends on the energy levels of the material and on particle size. From a practical angle, such questions are directly relevant to any heterogeneous system exposed to radiation. High-level waste temporarily stored in underground tanks, low-level waste permanently stored in humid grout, or soil particles migrating in geological formations are but a few examples

Influence of near-bottom re-suspended sediment on benthic light availability

DEFF Research Database (Denmark)

Pedersen, Troels Møller; Gallegos, Charles L.; Nielsen, Søren Laurentius

2012-01-01

Increased light attenuation in the water column is a common consequence of the increased organic loading that accompanies anthropogenic eutrophication in coastal systems. Frequently, the best water quality correlate of the light attenuation coefficient is the total suspended solids, even in systems......-bottomlight attenuation using an array of in situ light sensors with very close spacing near the sediment–water interface and a radiative transfer (RT) modeling with the software “Hydrolight”. We found that the light attenuation coefficient over 4.5 cm just above the bottom exceeded the attenuation found higher...... in the water column by a factor ranging from 1.6 to >30. RT modeling indicated that light received at the bottom could be overestimated by a factor 4 or more by extrapolating measurements not taking the near-bottomlight attenuation into account. The results may help explain the wide range of seagrass light...

Development of novel cilostazol-loaded solid SNEDDS using a SPG membrane emulsification technique: Physicochemical characterization and in vivo evaluation.

Science.gov (United States)

Mustapha, Omer; Kim, Kyung Soo; Shafique, Shumaila; Kim, Dong Shik; Jin, Sung Giu; Seo, Youn Gee; Youn, Yu Seok; Oh, Kyung Taek; Lee, Beom-Jin; Park, Young Joon; Yong, Chul Soon; Kim, Jong Oh; Choi, Han-Gon

2017-02-01

The objective of this study was to develop a novel solid self-nanoemulsifying drug delivery system (SNEDDS) using a membrane emulsification technique involving Shirasu porous glass (SPG) which produced very small and uniform emulsion droplets, resulting in enhanced solubility, dissolution and oral bioavailability of poorly water-soluble cilostazol. The effects of carriers on the drug solubility were assessed, and pseudo-ternary phase diagrams were plotted. Among the liquid SNEDDS formulations tested, the liquid SNEDDS composed of peceol (oil), Tween 20 (surfactant) and Labrasol (cosurfactant) at a weight ratio of 15/55/30, produced the smallest emulsion droplet size. The cilostazol-loaded liquid SNEDDS formulation was suspended in the distilled water and subjected to SPG membrane emulsification. Calcium silicate was added as a solid carrier in this liquid SNEDDS, completely suspended and spray-dried, leading to the production of a cilostazol-loaded solid SNEDDS. The emulsion droplet size, solubility and dissolution of the emulsified solid SNEDDS were assessed as compared to the solid SNEDDS prepared without emulsification. Moreover, the physicochemical characteristics and pharmacokinetics in rats were evaluated with the emulsified solid SNEDDS. The emulsified solid SNEDDS provided significantly smaller and more uniform nanoemulsions than did the non-emulsified solid SNEDDS. The emulsified solid SNEDDS showed significantly higher drug solubility and dissolution as compared to the non-emulsified solid SNEDDS. The crystalline drug in it was converted into the amorphous state. Moreover, in rats, it gave significantly higher initial plasma concentrations and AUC compared to the drug powder, suggesting its improved oral bioavailability of cilostazol. Thus, this novel solid SNEDDS developed using a membrane emulsification technique represents a potentially powerful oral delivery system for cilostazol. Copyright © 2016 Elsevier B.V. All rights reserved.

An analysis of bedload and suspended load interactions

Science.gov (United States)

Recking, alain; Navratil, Oldrich

2013-04-01

Several approaches were used to develop suspension equations. It includes semi-theoretical equations based on the convection diffusion equation (Einstein 1950; Van Rijn 1984; Camenen and Larson 2008; Julien 2010), semi-empirical tools based on energy concept (Velikanov 1954; Bagnold 1966), empirical adjustments (Prosser and Rusttomji 2000). One essential characteristic of all these equations is that most of them were developed by considering continuity between bedload and suspended load, and that the partitioning between these two modes of transport evolves progressively with increasing shear stress, which is the case for fine bed materials. The use of these equations is thus likely to be welcome in estuaries or lowland sandy rivers, but may be questionable in gravel-bed rivers and headwater streams where the bed is usually structured vertically and fine sediments potentially contributing to suspension are stored under a poorly mobile surface armour comprising coarse sediments. Thus one question this work aimed to answer is does the presence of an armour at the bed surface influence suspended load? This was investigated through a large field data set comprising instantaneous measurements of both bedload and suspension. We also considered the river characteristics, distinguishing between lowland rivers, gravel bed rivers and headwater streams. The results showed that a correlation exist between bedload and suspension for lowland and gravel bed rivers. This suggests that in gravel bed rivers a large part of the suspended load is fed by subsurface material, and depends on the remobilization of the surface material. No correlation was observed for head water streams where the sediment production is more likely related to hillslope processes. These results were used with a bedload transport equation for proposing a method for suspended load estimate. The method is rough, but especially for gravel bed rivers, it predicts suspended load reasonably well when compared to

Development and Optimization of a Flocculation Procedure for Improved Solid-Liquid Separation of Digested Biomass

Energy Technology Data Exchange (ETDEWEB)

Patton, Caroline; Lischeske, James J.; Sievers, David A.

2015-11-03

One viable treatment method for conversion of lignocellulosic biomass to biofuels begins with saccharification (thermochemical pretreatment and enzymatic hydrolysis), followed by fermentation or catalytic upgrading to fuels such as ethanol, butanol, or other hydrocarbons. The post-hydrolysis slurry is typically 4-8 percent insoluble solids, predominantly consisting of lignin. Suspended solids are known to inhibit fermentation as well as poison catalysts and obstruct flow in catalyst beds. Thus a solid-liquid separation following enzymatic hydrolysis would be highly favorable for process economics, however the material is not easily separated by filtration or gravimetric methods. Use of a polyacrylamide flocculant to bind the suspended particles in a corn stover hydrolyzate slurry into larger flocs (1-2mm diameter) has been found to be extremely helpful in improving separation. Recent and ongoing research on novel pretreatment methods yields hydrolyzate material with diverse characteristics. Therefore, we need a thorough understanding of rapid and successful flocculation design in order to quickly achieve process design goals. In this study potential indicators of flocculation performance were investigated in order to develop a rapid analysis method for flocculation procedure in the context of a novel hydrolyzate material. Flocculation conditions were optimized on flocculant type and loading, pH, and mixing time. Filtration flux of the hydrolyzate slurry was improved 170-fold using a cationic polyacrylamide flocculant with a dosing of approximately 22 mg flocculant/g insoluble solids at an approximate pH of 3. With cake washing, sugar recovery exceeded 90 percent with asymptotic yield at 15 L wash water/kg insoluble solids.

Promoting Therapists? Use of Motor Learning Strategies within Virtual Reality-Based Stroke Rehabilitation

OpenAIRE

Levac, Danielle E.; Glegg, Stephanie M. N.; Sveistrup, Heidi; Colquhoun, Heather; Miller, Patricia; Finestone, Hillel; DePaul, Vincent; Harris, Jocelyn E.; Velikonja, Diana

2016-01-01

Purpose Therapists use motor learning strategies (MLSs) to structure practice conditions within stroke rehabilitation. Virtual reality (VR)-based rehabilitation is an MLS-oriented stroke intervention, yet little support exists to assist therapists in integrating MLSs with VR system use. Method A pre-post design evaluated a knowledge translation (KT) intervention incorporating interactive e-learning and practice, in which 11 therapists learned how to integrate MLSs within VR-based therapy. Sel...

Temperature signal in suspended sediment export from an Alpine catchment

Science.gov (United States)

Costa, Anna; Molnar, Peter; Stutenbecker, Laura; Bakker, Maarten; Silva, Tiago A.; Schlunegger, Fritz; Lane, Stuart N.; Loizeau, Jean-Luc; Girardclos, Stéphanie

2018-01-01

Suspended sediment export from large Alpine catchments ( > 1000 km2) over decadal timescales is sensitive to a number of factors, including long-term variations in climate, the activation-deactivation of different sediment sources (proglacial areas, hillslopes, etc.), transport through the fluvial system, and potential anthropogenic impacts on the sediment flux (e.g. through impoundments and flow regulation). Here, we report on a marked increase in suspended sediment concentrations observed near the outlet of the upper Rhône River Basin in the mid-1980s. This increase coincides with a statistically significant step-like increase in basin-wide mean air temperature. We explore the possible explanations of the suspended sediment rise in terms of changes in water discharge (transport capacity), and the activation of different potential sources of fine sediment (sediment supply) in the catchment by hydroclimatic forcing. Time series of precipitation and temperature-driven snowmelt, snow cover, and ice melt simulated with a spatially distributed degree-day model, together with erosive rainfall on snow-free surfaces, are tested to explore possible reasons for the rise in suspended sediment concentration. We show that the abrupt change in air temperature reduced snow cover and the contribution of snowmelt, and enhanced ice melt. The results of statistical tests show that the onset of increased ice melt was likely to play a dominant role in the suspended sediment concentration rise in the mid-1980s. Temperature-driven enhanced melting of glaciers, which cover about 10 % of the catchment surface, can increase suspended sediment yields through an increased contribution of sediment-rich glacial meltwater, increased sediment availability due to glacier recession, and increased runoff from sediment-rich proglacial areas. The reduced extent and duration of snow cover in the catchment are also potential contributors to the rise in suspended sediment concentration through

Application of constructed wetlands to the treatment of leachates from a municipal solid waste landfill in Ibadan, Nigeria.

Science.gov (United States)

Aluko, Olufemi Oludare; Sridhar, M K C

2005-06-01

Leachates are wastewater generated principally from landfills and solid waste disposal sites. Leachates emanating from municipal wastes are a major source of surface and groundwater pollution worldwide. Globally, leachates have been implicated in low yield of farm produce, developmental anomalies, low birth weights, leukemia incidence, and other cancers in communities around the site. They have also been implicated in hazards to the environment, loss of biodiversity, and contamination of water sources. At Aba-Eku in Nigeria, leachates are being discharged into the Omi Stream without treatment. A study was conducted on a method of leachate treatment that passes the leachate through constructed wetlands using Ipomoea aquatica (Forsk), a locally available plant found close to the landfill site. The aim of the study was to evolve a sustainable and cost-effective method of treatment whose effluents can be discharged into the Omi Stream with no or minimal impact. The study was descriptive and analytical in design. Samples were collected and analyzed with standard methods for pH, suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia, nitrate, and trace metals. Raw leachates were turbid and amber in color and contained suspended solids (197.5 mg/L), ammonia (610.9 mg/L), lead (1.64 mg/L), iron (198.10 mg/L), and manganese (23.20 mg/L). When the leachates were passed through the constructed wetland with eight hours' detention time, effluents showed significant reductions in suspended solids (81.01 percent), BOD (86.03 percent), and ammonia (97.77 percent). The study shows that a constructed wetland is a feasible tool for the treatment of leachates before their disposal into the environment in Nigeria and can help safeguard environmental quality.

Aerial Photo Utilization in Estimating Suspended Sediment in the Wuryantoro Watershed, Wonogiri

Directory of Open Access Journals (Sweden)

Sugiharto Budi Santoso

2004-01-01

Full Text Available Suspended sediment load flowing out from a watershed is normally predicated by analysis os suspended sediment of water sample, and the volume of suspended sediment be calculated based on sediment concentration and river discharge. Such field measurements need a lot of field data and they are time consuming. Another method for prediction of suspended sediment by using remote sensing imagery data and recorded rainfall data. The objective of this research is to 1 examine the capability of remote sensing technique to obtain the parameters of the physical data of land in the prediction of suspended sediment; 2 examine the accuracy of the model for prediction suspended sediment. This research is carried out in Wuryantoro watershed, Wonogiri. The main data to obtain the parameters of the physical data of land is infrared aerial photograph on scale 1 : 10.000. the method that used in this research is interpretation of remote sensing imagery data, combined with rainfall data. The result show that the accuracy of landuse is 88.5%, the accuracy of slope is 87.67%. the accuracy of the prediction of suspended sediment by model A3 87.07%, model C1 86.63%, model C2 90.57%, model A8 84.13%, model A9 80.1%, and model C4 78.6%.

Influence of sampling frequency and load calculation methods on quantification of annual river nutrient and suspended solids loads.

Science.gov (United States)

Elwan, Ahmed; Singh, Ranvir; Patterson, Maree; Roygard, Jon; Horne, Dave; Clothier, Brent; Jones, Geoffrey

2018-01-11

Better management of water quality in streams, rivers and lakes requires precise and accurate estimates of different contaminant loads. We assessed four sampling frequencies (2 days, weekly, fortnightly and monthly) and five load calculation methods (global mean (GM), rating curve (RC), ratio estimator (RE), flow-stratified (FS) and flow-weighted (FW)) to quantify loads of nitrate-nitrogen (NO 3 - -N), soluble inorganic nitrogen (SIN), total nitrogen (TN), dissolved reactive phosphorus (DRP), total phosphorus (TP) and total suspended solids (TSS), in the Manawatu River, New Zealand. The estimated annual river loads were compared to the reference 'true' loads, calculated using daily measurements of flow and water quality from May 2010 to April 2011, to quantify bias (i.e. accuracy) and root mean square error 'RMSE' (i.e. accuracy and precision). The GM method resulted into relatively higher RMSE values and a consistent negative bias (i.e. underestimation) in estimates of annual river loads across all sampling frequencies. The RC method resulted in the lowest RMSE for TN, TP and TSS at monthly sampling frequency. Yet, RC highly overestimated the loads for parameters that showed dilution effect such as NO 3 - -N and SIN. The FW and RE methods gave similar results, and there was no essential improvement in using RE over FW. In general, FW and RE performed better than FS in terms of bias, but FS performed slightly better than FW and RE in terms of RMSE for most of the water quality parameters (DRP, TP, TN and TSS) using a monthly sampling frequency. We found no significant decrease in RMSE values for estimates of NO 3 - N, SIN, TN and DRP loads when the sampling frequency was increased from monthly to fortnightly. The bias and RMSE values in estimates of TP and TSS loads (estimated by FW, RE and FS), however, showed a significant decrease in the case of weekly or 2-day sampling. This suggests potential for a higher sampling frequency during flow peaks for more precise

Suspended HOPG nanosheets for HOPG nanoresonator engineering and new carbon nanostructure synthesis

International Nuclear Information System (INIS)

Rose, F; Debray, A; Martin, P; Fujita, H; Kawakatsu, H

2006-01-01

Suspended highly oriented pyrolytic graphite (HOPG) nanosheets (10-300 nm thick) were created by direct mechanical cleavage of a bulk HOPG crystal onto silicon micropillars and microtracks. We show that suspended HOPG nanosheets can be used to engineer HOPG nanoresonators such as membranes, bridges, and cantilevers as thin as 28 carbon atom layers. We measured by Doppler laser heterodyne interferometry that the discrete vibration modes of an HOPG nanosheet membrane and the resonance frequency of a FIB-created HOPG microcantilever lie in the MHz frequency regime. Moreover, a new carbon nanostructure, named 'nanolace', was synthesized by focused ion beam (FIB) sputtering of suspended HOPG nanosheets. Graphite nanosheets suspended on micropillars were eroded by a FIB to create self-oriented pseudo-periodical ripples. Additional sputtering and subsequent milling of these ripples led to the formation of honeycomb-like shaped nanolaces suspended and linked by ribbons

Effects of alcohols on gas holdup and volumetric liquid-phase mass transfer coefficient in gel-particle-suspended bubble column

Energy Technology Data Exchange (ETDEWEB)

Salvacion, J.; Murayama, M.; Otaguchi, K.; Koide, K. [Tokyo Institute of Technology, Tokyo (Japan)

1995-08-20

The effects of alcohols, column dimensions, gas velocity, physical properties of liquids, and gel particles on the gas holdup e{sub G} and the volumetric liquid-phase mass transfer coefficient k{sub L}a in a gel-particle-suspended bubble column under liquid-solid batch operation were studied experimentally. It was shown that addition of at alcohols to water generally increases e{sub G}. However, k{sub L}a values in aqueous solutions of alcohols became larger or smaller than those in water, according to the kind and concentration of the alcohol added to water. It was also shown that the presence of suspended gel-particles in the bubble column reduces values of e{sub G} and k{sub L}a. Based on these observations, empirical equations for e{sub G} in the transition regime in an ethanol solution, for e{sub G} in the heterogeneous now regime applicable to various alcohol solutions and for k{sub L}a in both now regimes were proposed. 18 refs., 12 figs., 3 tabs.

The features of ballistic electron transport in a suspended quantum point contact

International Nuclear Information System (INIS)

Shevyrin, A. A.; Budantsev, M. V.; Bakarov, A. K.; Toropov, A. I.; Pogosov, A. G.; Ishutkin, S. V.; Shesterikov, E. V.

2014-01-01

A suspended quantum point contact and the effects of the suspension are investigated by performing identical electrical measurements on the same experimental sample before and after the suspension. In both cases, the sample demonstrates conductance quantization. However, the suspended quantum point contact shows certain features not observed before the suspension, namely, plateaus at the conductance values being non-integer multiples of the conductance quantum, including the “0.7-anomaly.” These features can be attributed to the strengthening of electron-electron interaction because of the electric field confinement within the suspended membrane. Thus, the suspended quantum point contact represents a one-dimensional system with strong electron-electron interaction

Analysis of the Danube river suspended load regime

International Nuclear Information System (INIS)

Lukac, M.

2004-01-01

In this presentation author deals with the analysis of the Danube river suspended load regime at the Slovak section of Danube. It is concluded and recommended: Suspended load transport at the Slovak section of Danube decreases in the downstream directions - annual averages: Utilize relation of the Water Research Institute in Medvedov, the relation of the Slovak Hydrometeorological Institute is probably slightly underestimated; Distribution of suspended load concentration in the cross-section is influenced mainly with local hydraulic and morphological conditions; Measured flow velocity in the range 0.6 - 2.65 m/sec -1 , influenced with water level slope; Silt particles the most numerous, less numerous sandy and clayey particles; Bratislava 3.54 mil. tonnes, Medvedov 2.22 mil. tonnes, and Komarno 1.96 mil. tonnes; Recommendation to measure actual volume of the Cunovo reservoir, in order to validate sediment transport balance; Recommendation to continue in a complex monitoring programme of sediment transport

Seasonal changes in suspended sediment load in the Gauthami-Godavari Estuary

Digital Repository Service at National Institute of Oceanography (India)

Reddy, N.P.C.; Rao, B.P.; Rao, K.M.; Rao, V.S.

Studies carried out on suspended matter characteristics of the the Gautami Godavari Estuary revealed that the concentration of suspended matter (CSM) during southwest monsoon influenced mainly by the increased run off at both Neelarevu and Vrudha...

Experimental study on mechanism and shape characteristics of suspended flexible dam

Science.gov (United States)

Wang, Jian-zhong; Fan, Hong-xia; Zhu, Li-jun

2014-12-01

Hydraulic structures such as groin, longitudinal dike and seawall are common in water conservancy and water transportation engineering projects at home and abroad, which have long been dominated by solid mass structural form. With brush and stone as building materials, this kind of structure has an obvious engineering effect. However, it not only requires huge capital investments, but also has negative impacts on the ecological environment. The suspended flexible dam is an innovative engineering measure, and few theoretical and experimental researches of this type dam can be found at present. This paper studies the mechanism and shape characteristics of this dam and obtains the dynamic equilibrium equation of flexible dam, the float buoyancy expression, and the condition for transformation among three forms of the underwater shape of the dam. The results are valuable in engineering application and can be used as the reference for the future work due to the distinctive design philosophy, the small negative effects on environment and the consistency for sustainable development.

Prediction of maximal lactate steady state in runners with an incremental test on the field.

Science.gov (United States)

Leti, Thomas; Mendelson, Monique; Laplaud, David; Flore, Patrice

2012-01-01

During a maximal incremental ergocycle test, the power output associated with Respiratory Exchange Ratio equal to 1.00 (RER = 1.00) predicts maximal lactate steady state (MLSS). We hypothesised that these results are transferable for runners on the field. Fourteen runners performed a maximal progressive test, to assess the speed associated with RER = 1.00, and several 30 minutes constant velocity tests to determine the speed at MLSS. We observed that the speeds at RER = 1.00, at the second ventilatory threshold (VT2) and at MLSS did not differ (15.7 ± 1.1 km · h⁻¹, 16.2 ± 1.4 km · h⁻¹, 15.5 ± 1.1 km · h⁻¹ respectively). The speed associated with RER = 1.00 was better correlated with that at MLSS (r = 0.79; p = 0.0008) than that at VT2 (r = 0.73; p = 0.002). Neither the concentration of blood lactate nor the heart rate differed between the speed at RER = 1.00 and that at MLSS from the 10th and the 30th minute of the constant velocity test. Bland and Altman analysis showed a fair agreement between the speed at MLSS and that at RER (0.2 ± 1.4 km · h⁻¹). This study demonstrated that the speed associated with RER = 1.00 determined during maximal progressive track running allows a fair estimation of the speed associated with MLSS, markedly decreasing the burden of numerous invasive tests required to assess it.

Platform for monitoring water and solid fluxes in mountainous rivers

Science.gov (United States)

Nord, Guillaume; Esteves, Michel; Aubert, Coralie; Belleudy, Philippe; Coulaud, Catherine; Bois, Jérôme; Geay, Thomas; Gratiot, Nicolas; Legout, Cédric; Mercier, Bernard; Némery, Julien; Michielin, Yoann

2016-04-01

The project aims to develop a platform that electronically integrates a set of existing sensors for the continuous measurement at high temporal frequency of water and solid fluxes (bed load and suspension), characteristics of suspended solids (distribution in particle size, settling velocity of the particles) and other variables on water quality (color, nutrient concentration). The project is preferentially intended for rivers in mountainous catchments draining areas from 10 to 1000 km², with high suspended sediment concentrations (maxima between 10 and 300 g/l) and highly dynamic behavior, water discharge varying of several orders of magnitude in a short period of time (a few hours). The measurement of water and solid fluxes in this type of river remains a challenge and, to date, there is no built-in device on the market to continuously monitor all these variables. The development of this platform is based on a long experience of measurement of sediment fluxes in rivers within the French Critical Zone Observatories (http://portailrbv.sedoo.fr/), especially in the Draix-Bléone (http://oredraixbleone.irstea.fr/) and OHMCV (http://www.ohmcv.fr/) observatories. The choice was made to integrate in the platform instruments already available on the market and currently used by the scientific community (water level radar, surface velocity radar, turbidity sensor, automatic water sampler, video camera) and to include also newly developed instruments (System for the Characterization of Aggregates and Flocs - see EGU2016-8542 - and hydrophone) or commercial instruments (spectrophotometer and radiometer) to be tested in surface water with high suspended sediment concentration. Priority is given to non-intrusive instruments due to their robustness in this type of environment with high destructive potential. Development work includes the construction of a platform prototype "smart" and remotely configurable for implantation in an isolated environment (absence of electric

Temporal and spatial changes of cadmium in the near-bottom suspended matter of the Pomeranian Bay - Arkona Deep system

Directory of Open Access Journals (Sweden)

Andrzej Staniszewski

2000-12-01

Full Text Available Owing to the high toxicity of cadmium (Cd towards biota and the considerable quantities of this element entering the environment from anthropogenic sources, interest in its biogeochemistry is increasing. This is also true for the marine environment, which serves as a sink for both natural and anthropogenic Cd loads entering the hydrosphere and the atmosphere. The distribution of Cd in the coastal zone of the marine environment is governed primarily by the flux of the so-called fluffy layer suspended matter (FLSM, which spreads across the top of the sea floor as a several-centimetre-thick layer containing highly concentrated suspended matter. Both total contents and solid speciation of Cd was measured in FLSM collected in the Pomeranian Bay - Arkona Deep system (Western Baltic Proper in the course of the three-year-long study. Seasonal changes in the total Cd content (0.5-1.8 µg g–1 dry matter were attributed to the contribution of organic suspensions originating from algal blooms. The decreasing content of Cd in FLSM offshore is due to the input of Cd-rich suspended matter from the River Odra (Oder, and the decreasing organic matter content in FLSM with increasing depth. The contribution of labile fractions (adsorbed and bound to iron III hydroxides was found to be from 50 to 75% of the total content. In view of the substantial mobility and bioavailability of the fractions, this is a highly alarming feature.

Temperature signal in suspended sediment export from an Alpine catchment

Directory of Open Access Journals (Sweden)

A. Costa

2018-01-01

Full Text Available Suspended sediment export from large Alpine catchments ( >  1000 km2 over decadal timescales is sensitive to a number of factors, including long-term variations in climate, the activation–deactivation of different sediment sources (proglacial areas, hillslopes, etc., transport through the fluvial system, and potential anthropogenic impacts on the sediment flux (e.g. through impoundments and flow regulation. Here, we report on a marked increase in suspended sediment concentrations observed near the outlet of the upper Rhône River Basin in the mid-1980s. This increase coincides with a statistically significant step-like increase in basin-wide mean air temperature. We explore the possible explanations of the suspended sediment rise in terms of changes in water discharge (transport capacity, and the activation of different potential sources of fine sediment (sediment supply in the catchment by hydroclimatic forcing. Time series of precipitation and temperature-driven snowmelt, snow cover, and ice melt simulated with a spatially distributed degree-day model, together with erosive rainfall on snow-free surfaces, are tested to explore possible reasons for the rise in suspended sediment concentration. We show that the abrupt change in air temperature reduced snow cover and the contribution of snowmelt, and enhanced ice melt. The results of statistical tests show that the onset of increased ice melt was likely to play a dominant role in the suspended sediment concentration rise in the mid-1980s. Temperature-driven enhanced melting of glaciers, which cover about 10 % of the catchment surface, can increase suspended sediment yields through an increased contribution of sediment-rich glacial meltwater, increased sediment availability due to glacier recession, and increased runoff from sediment-rich proglacial areas. The reduced extent and duration of snow cover in the catchment are also potential contributors to the rise in suspended sediment

Suspended graphene variable capacitor

OpenAIRE

AbdelGhany, M.; Mahvash, F.; Mukhopadhyay, M.; Favron, A.; Martel, R.; Siaj, M.; Szkopek, T.

2016-01-01

The tuning of electrical circuit resonance with a variable capacitor, or varactor, finds wide application with the most important being wireless telecommunication. We demonstrate an electromechanical graphene varactor, a variable capacitor wherein the capacitance is tuned by voltage controlled deflection of a dense array of suspended graphene membranes. The low flexural rigidity of graphene monolayers is exploited to achieve low actuation voltage in an ultra-thin structure. Large arrays compr...

Optical fiber end-facet polymer suspended-mirror devices

Science.gov (United States)

Yao, Mian; Wu, Jushuai; Zhang, A. Ping; Tam, Hwa-Yaw; Wai, P. K. A.

2017-04-01

This paper presents a novel optical fiber device based on a polymer suspended mirror on the end facet of an optical fiber. With an own-developed optical 3D micro-printing technology, SU-8 suspended-mirror devices (SMDs) were successfully fabricated on the top of a standard single-mode optical fiber. Optical reflection spectra of the fabricated SU- 8 SMDs were measured and compared with theoretical analysis. The proposed technology paves a way towards 3D microengineering of the small end-facet of optical fibers to develop novel fiber-optic sensors.

Impact of sound attenuation by suspended sediment on ADCP backscatter calibrations

NARCIS (Netherlands)

Sassi, M.G.; Hoitink, A.J.F.; Vermeulen, B.

2012-01-01

Although designed for velocity measurements, acoustic Doppler current profilers (ADCPs) are widely being used to monitor suspended particulate matter in rivers and in marine environments. To quantify mass concentrations of suspended matter, ADCP backscatter is generally calibrated with in situ

Suspended microstructures of epoxy based photoresists fabricated with UV photolithography

DEFF Research Database (Denmark)

Hemanth, Suhith; Anhøj, Thomas Aarøe; Caviglia, Claudia

2017-01-01

In this work we present an easy, fast, reliable and low cost microfabrication technique for fabricating suspended microstructures of epoxy based photoresistswith UV photolithography. Two different fabrication processes with epoxy based resins (SU-8 and mr-DWL) using UV exposures at wavelengths...... of 313 nm and 405 nm were optimized and compared in terms of structural stability, control of suspended layer thickness and resolution limits. A novel fabrication process combining the two photoresists SU-8 and mr-DWL with two UV exposures at 365 nm and 405 nm respectively provided a wider processing...... window for definition of well-defined suspended microstructures with lateral dimensions down to 5 μmwhen compared to 313 nm or 365 nm UV photolithography processes....

300 GPM Solids Removal System A True Replacement for Back Flushable Powdered Filter Systems - 13607

Energy Technology Data Exchange (ETDEWEB)

Ping, Mark R.; Lewis, Mark [EnergySolutions, Suite 100, Center Point II, 100 Center Point Circle, Columbia, SC 29210 (United States)

2013-07-01

The EnergySolutions Solids Removal System (SRS) utilizes stainless steel cross-flow ultra-filtration (XUF) technology which allows it to reliably remove suspended solids greater than one (1) micron from liquid radwaste streams. The SRS is designed as a pre-treatment step for solids separation prior to processing through other technologies such as Ion Exchange Resin (IER) and/or Reverse Osmosis (RO), etc. Utilizing this pre-treatment approach ensures successful production of reactor grade water while 1) decreasing the amount of radioactive water being discharged to the environment; and 2) decreasing the amount of radioactive waste that must ultimately be disposed of due to the elimination of spent powdered filter media. (authors)

300 GPM Solids Removal System A True Replacement for Back Flushable Powdered Filter Systems - 13607

International Nuclear Information System (INIS)

Ping, Mark R.; Lewis, Mark

2013-01-01

The EnergySolutions Solids Removal System (SRS) utilizes stainless steel cross-flow ultra-filtration (XUF) technology which allows it to reliably remove suspended solids greater than one (1) micron from liquid radwaste streams. The SRS is designed as a pre-treatment step for solids separation prior to processing through other technologies such as Ion Exchange Resin (IER) and/or Reverse Osmosis (RO), etc. Utilizing this pre-treatment approach ensures successful production of reactor grade water while 1) decreasing the amount of radioactive water being discharged to the environment; and 2) decreasing the amount of radioactive waste that must ultimately be disposed of due to the elimination of spent powdered filter media. (authors)

The impacts of land reclamation on suspended-sediment dynamics in Jiaozhou Bay, Qingdao, China

Science.gov (United States)

Gao, Guan Dong; Wang, Xiao Hua; Bao, Xian Wen; Song, Dehai; Lin, Xiao Pei; Qiao, Lu Lu

2018-06-01

A three-dimensional, high-resolution tidal model coupled with the UNSW sediment model (UNSW-Sed) based on Finite Volume Coastal Ocean Model (FVCOM) was set up to study the suspended-sediment dynamics and its change in Jiaozhou Bay (JZB) due to land reclamation over the period 1935 to 2008. During the past decades, a large amount of tidal flats were lost due to land reclamation. Other than modulating the tides, the tidal flats are a primary source for sediment resuspensions, leading to turbidity maxima nearshore. The tidal dynamics are dominant in controlling the suspended-sediment dynamics in JZB and have experienced significant changes with the loss of tidal flats due to the land reclamation. The sediment model coupled with the tide model was used to investigate the changes in suspended-sediment dynamics due to the land reclamation from 1935 to 2008, including suspended-sediment concentrations (SSC) and the horizontal suspended-sediment fluxes. This model can predict the general patterns of the spatial and temporal variation of SSC. The model was applied to investigate how the net transport of suspended sediments between JZB and its adjacent sea areas changed with land reclamation: in 1935 the net movement of suspended sediments was from JZB to the adjacent sea (erosion for JZB), primarily caused by horizontal advection associated with a horizontal gradient in the SSC; This seaward transport (erosion for JZB) had gradually declined from 1935 to 2008. If land reclamation on a large scale is continued in future, the net transport between JZB and the adjacent sea would turn landward and JZB would switch from erosion to siltation due to the impact of land reclamation on the horizontal advection of suspended sediments. We also evaluate the primary physical mechanisms including advection of suspended sediments, settling lag and tidal asymmetry, which control the suspended-sediment dynamics with the process of land reclamation.

Suspended HfO2 photonic crystal slab on III-nitride/Si platform

International Nuclear Information System (INIS)

Wang, Yongjin; Feng, Jiao; Cao, Ziping; Zhu, Hongbo

2014-01-01

We present here the fabrication of suspended hafnium oxide (HfO 2 ) photonic crystal slab on a III-nitride/Si platform. The calculations are performed to model the suspended HfO 2 photonic crystal slab. Aluminum nitride (AlN) film is employed as the sacrificial layer to form air gap. Photonic crystal patterns are defined by electron beam lithography and transferred into HfO 2 film, and suspended HfO 2 photonic crystal slab is achieved on a III-nitride/Si platform through wet-etching of AlN layer in the alkaline solution. The method is promising for the fabrication of suspended HfO 2 nanostructures incorporating into a III-nitride/Si platform, or acting as the template for epitaxial growth of III-nitride materials. (orig.)

Influence of secondary settling tank performance on suspended solids mass balance in activated sludge systems.

Science.gov (United States)

Patziger, M; Kainz, H; Hunze, M; Józsa, J

2012-05-01

Secondary settling is the final step of the activated sludge-based biological waste water treatment. Secondary settling tanks (SSTs) are therefore an essential unit of producing a clear effluent. A further important function of SSTs is the sufficient thickening to achieve highly concentrated return sludge and biomass within the biological reactor. In addition, the storage of activated sludge is also needed in case of peak flow events (Ekama et al., 1997). Due to the importance of a high SST performance the problem has long been investigated (Larsen, 1977; Krebs, 1991; Takács et al., 1991; Ekama et al., 1997; Freimann, 1999; Patziger et al., 2005; Bürger et al., 2011), however, a lot of questions are still to solve regarding e.g. the geometrical features (inflow, outflow) and operations (return sludge control, scraper mechanism, allowable maximum values of surface overflow rates). In our study we focused on SSTs under dynamic load considering both the overall unsteady behaviour and the features around the peaks, investigating the effect of various sludge return strategies as well as the inlet geometry on SST performance. The main research tool was a FLUENT-based novel mass transport model consisting of two modules, a 2D axisymmetric SST model and a mixed reactor model of the biological reactor (BR). The model was calibrated and verified against detailed measurements of flow and concentration patterns, sludge settling, accompanied with continuous on-line measurement of in- and outflow as well as returned flow rates of total suspended solids (TSS) and water. As to the inlet arrangement a reasonable modification of the geometry could result in the suppression of the large scale flow structures of the sludge-water interface thus providing a significant improvement in the SST performance. Furthermore, a critical value of the overflow rate (q(crit)) was found at which a pronounced large scale circulation pattern develops in the vertical plane, the density current in

MEMS-Based Fuel Reformer with Suspended Membrane Structure

Science.gov (United States)

Chang, Kuei-Sung; Tanaka, Shuji; Esashi, Masayoshi

We report a MEMS-based fuel reformer for supplying hydrogen to micro-fuel cells for portable applications. A combustor and a reforming chamber are fabricated at either side of a suspended membrane structure. This design is used to improve the overall thermal efficiency, which is a critical issue to realize a micro-fuel reformer. The suspended membrane structure design provided good thermal isolation. The micro-heaters consumed 0.97W to maintain the reaction zone of the MEMS-based fuel reformer at 200°C, but further power saving is necessary by improving design and fabrication. The conversion rate of methanol to hydrogen was about 19% at 180°C by using evaporated copper as a reforming catalyst. The catalytic combustion of hydrogen started without any assistance of micro-heaters. By feeding the fuel mixture of an equivalence ratio of 0.35, the temperature of the suspended membrane structure was maintained stable at 100°C with a combustion efficiency of 30%. In future works, we will test a micro-fuel reformer by using a micro-combustor to supply heat.

77 FR 44233 - Clothianidin; Emergency Petition To Suspend; Notice of Availability

Science.gov (United States)

2012-07-27

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2012-0344; FRL-9355-1] Clothianidin; Emergency.... SUMMARY: PANNA and others submitted a request for the EPA to immediately suspend Clothianidin and take... the EPA suspend registrations for the insecticide clothianidin for the four following reasons: (1) To...

20 CFR 408.802 - When will we suspend your SVB payments?

Science.gov (United States)

2010-04-01

....802 Section 408.802 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Suspensions and Terminations Suspension § 408.802 When will we suspend your SVB... underway for a substitute representative payee.) (b) Effect of suspension. When we correctly suspend your...

H2S induces a suspended animation-like state in mice.

Science.gov (United States)

Blackstone, Eric; Morrison, Mike; Roth, Mark B

2005-04-22

Mammals normally maintain their core body temperature (CBT) despite changes in environmental temperature. Exceptions to this norm include suspended animation-like states such as hibernation, torpor, and estivation. These states are all characterized by marked decreases in metabolic rate, followed by a loss of homeothermic control in which the animal's CBT approaches that of the environment. We report that hydrogen sulfide can induce a suspended animation-like state in a nonhibernating species, the house mouse (Mus musculus). This state is readily reversible and does not appear to harm the animal. This suggests the possibility of inducing suspended animation-like states for medical applications.

The effects of Hurricane Hugo on suspended-sediment loads, Lago Loiza Basin, Puerto Rico

Science.gov (United States)

Gellis, A.

1993-01-01

In the two main tributaries that enter Lago Loiza, Rio Grande de Loiza and Rio Gurabo, 99 600 tonnes of suspended sediment was transported by 58.2??106 m3 of runoff in a 48 h period. The storm-average suspended-sediment concentration in the Rio Grande de Loiza for Hurricane Hugo was 2290 mgl-1, the second lowest for the 12 storms that have been monitored at this site. In Rio Gurabo the storm-average suspended-sediment concentration was 1420 mg l -1, the sixth lowest recorded out of 15 monitored storms. In Quebrada Salvatierra, a small tributary to Rio Grande de Loiza, suspended-sediment concentrations were as low as 33 mg l-1 during peak runoff of 20m3s-1. Normally the suspended-sediment concentrations at this discharge are 300 mg l-1. Hurricane force winds seem to be the most important factor contributing to the lower than expected suspended-sediment loads. High winds caused vegetation and debris to be dislodged and displaced. Debris accumulated on hillslopes and in small channels, blocked bridges and formed debris dams. These dams caused local backwater effects that reduced stream velocities and decreased suspended-sediment loads. -from Author

A Generalized Mathematical Model for the Fracture Problem of the Suspended Highway

Directory of Open Access Journals (Sweden)

Zhao Ying

2017-01-01

Full Text Available In order to answer dangling fracture problems of highway, the suspended pavement equivalent for non - suspended pavement, through the special boundary conditions has been suspended highway stress field of expression, in accordance with the 3D fracture model of crack formation, and establish a vacant, a general mathematics model for fracture problems of highway and analysis in highway suspended segment weight and vehicle load limit of highway capacity of Pu For overturning road inPu is less than the force of carrying more than compared to the work and fruit Bridge Hydropower Station Road engineering examples to verify suspended highway should force field expressions for the correctness and applicability. The results show that: when the hanging ratio R 0. 243177 limits of Pu design axle load 100kN. When the vertical crack in the vacant in the direction of length greater than 0. 1, the ultimate bearing capacity is less than the design axle load 100kN; when the hanging ratio R is less than 0. 5, the road to local fracture, the ultimate bearing capacity of suspended stress field expressions in solution; when the hanging ratio is greater than or equal to 0. 5, the road does not reach the limit bearing capacity of the whole body; torque shear surface of the effect is far less than the bending moments on shear planes.

Suspended particle and drug ingredient concentrations in hospital dispensaries and implications for pharmacists' working environments.

Science.gov (United States)

Inaba, Ryoichi; Hioki, Atsushi; Kondo, Yoshihiro; Nakamura, Hiroki; Nakamura, Mitsuhiro

2016-03-01

The aim of this study was to assess the present status of working environments for pharmacists, including the concentrations of suspended particles and suspended drug ingredients in dispensaries. We conducted a survey on the work processes and working environment in 15 hospital dispensaries, and measured the concentrations of suspended particles and suspended drug ingredients using digital dust counter and high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. Of 25 types of powdered drugs that were frequently handled in the 15 dispensaries surveyed, 11 could be quantitatively determined. The amounts of suspended particles were relatively high, but below the reference value, in three dispensaries without dust collectors. The sedative-hypnotic drug zopiclone was detected in the suspended particles at one dispensary that was not equipped with dust collectors, and the antipyretic and analgesic drug acetaminophen was detected in two dispensaries equipped with dust collectors. There was no correlation between the daily number of prescriptions containing powdered drugs and the concentration of suspended particles in dispensaries. On the basis of the suspended particle concentrations measured, we concluded that dust collectors were effective in these dispensaries. However, suspended drug ingredients were detected also in dispensaries with dust collectors. These results suggest that the drug dust control systems of individual dispensaries should be properly installed and managed.

Solids loading evaluation for HB-line scrap recovery filters

International Nuclear Information System (INIS)

Crowder, M.L.

2000-01-01

The HB-Line Scrap Recovery facility uses wire screen filters to remove solids from plutonium-containing solutions transferred from the slab tank dissolvers. At times, the accumulation of solids is large enough to cause blinding (i.e., pluggage) of the filters. If the solids contain undissolved plutonium, significant accumulation of fissile material could impact operations. To address this potential issue, experiments were performed to define the minimum solids required to completely blind a filter. The solids loading experiments were performed by arranging 25- and 10-microm HB-Line filters in series to simulate the equipment in the scrap recovery process. Separate tests were performed using coarse and fine glass frit and cerium oxide powder suspended in 35 wt% sodium nitrate solution using a small turbine mixer. The solution and solids were transferred from a reservoir through the filter housings by vacuum. In each case, the 25-microm filter blinded first and was full of wet cake. After drying and accounting for the sodium nitrate in the filter cake, the following results were obtained. The results of the solids loading tests demonstrated that at least 800 g of solids accumulated in the filter housing before flow stopped. The actual amount of collected material was dependent upon the physical properties of the solids such as density and particle size. The mass of solids collected by the blinded 25-microm filter increased when successively finer solids were used in the experiments. Based on these results, one should anticipate that filters in the HB-Line Scrap Recovery Facility have the potential to collect similar quantities of material before transfer of solution from the dissolvers is severely impacted

19 CFR 351.222 - Revocation of orders; termination of suspended investigations.

Science.gov (United States)

2010-04-01

... orders; termination of suspended investigations. (a) Introduction. “Revocation” is a term of art that... that: (i) Producers accounting for substantially all of the production of the domestic like product to... 19 Customs Duties 3 2010-04-01 2010-04-01 false Revocation of orders; termination of suspended...

Suspended sediment load in the tidal zone of an Indonesian river

Directory of Open Access Journals (Sweden)

F. A. Buschman

2012-11-01

Full Text Available Forest clearing for reasons of timber production, open pit mining and the establishment of oil palm plantations generally results in excessively high sediment loads in tropical rivers. The increasing sediment loads pose a threat to coastal marine ecosystems, such as coral reefs. This study presents observations of suspended sediment loads in the Berau River (Kalimantan, Indonesia, which debouches into a coastal ocean that is a preeminent center of coral diversity. The Berau River is relatively small and drains a mountainous, still relatively pristine basin that receives abundant rainfall. In the tidal zone of the Berau River, flow velocity was measured over a large part of the river width using a horizontal acoustic Doppler current profiler (HADCP. Surrogate measurements of suspended sediment concentration were taken with an optical backscatter sensor (OBS. Averaged over the 6.5 weeks covered by the benchmark survey period, the suspended sediment load was estimated at 2 Mt yr⁻¹. Based on rainfall-runoff modeling though, the river discharge peak during the survey was supposed to be moderate and the yearly averaged suspended sediment load is most likely somewhat higher than 2 Mt yr⁻¹. The consequences of ongoing clearing of rainforest were explored using a plot-scale erosion model. When rainforest, which still covered 50–60% of the basin in 2007, is converted to production land, soil loss is expected to increase with a factor between 10 and 100. If this soil loss is transported seaward as suspended sediment, the increase in suspended sediment load in the Berau River would impose a severe stress on this global hotspot of coral reef diversity.

Electrodialytic remediation of suspended soil – Comparison of two different soil fractions

DEFF Research Database (Denmark)

Sun, Tian Ran; Ottosen, Lisbeth M.; Jensen, Pernille Erland

2012-01-01

Electrodialytic remediation (EDR) can be used for removal of heavy metals from suspended soil, which allows for the soil remediation to be a continuous process. The present paper focused on the processing parameters for remediation of a soil polluted with Cu and As from wood preservation. Six...... electrodialytic treatments lasting from 5 to 22 days with different liquid to solid ratio (L/S) and current intensity were conducted. Among treatments, the highest removal was obtained from the soil fines with 5mA current at L/S 3.5 after 22 days where 96% of Cu and 64% of As were removed. Comparing the removal...... from the original soil and the soil fines in experiments with identical charge transportation, higher removal efficiency was observed from the soil fines. Constant current with 5mA could be maintained at L/S 3.5 for the soil fines while not for the original soil. Doubling current to 10mA could...

Forty Cases of Insomnia Treated by Suspended Moxibustion at Baihui (GV 20)

Institute of Scientific and Technical Information of China (English)

JU Yan-li; CHI Xu; LIU Jian-xin

2009-01-01

Objective:To observe the therapeutic effect of suspended moxibustion at Baihui (GV 20) for insomnia.Methods: 75 cases were divided randomly into two groups, with 40 cases in the treatment group treated by suspended moxibustion over Baihui (GV 20) and 35 cases in the control group treated by oral administration of Estazolam. Results: The difference in therapeutic effect between the two groups was not statistically significant (P>0.1). Conclusion: It was concluded that suspended moxibustion at Baihui (GV 20) is as effective as Estazolam for insomnia.

Bed-levelling experiments with suspended load

NARCIS (Netherlands)

Talmon, A.M.; De Graaff, J.

1991-01-01

Bed-levelling experiments are conducted in a straight laboratory channel. The experiments involve a significant fraction of suspended sediment transport. The purpose of the experiments is to provide data for modelling of the direction of sediment transport on a transverse sloping alluvial river bed,

CHARACTERISATION OF SOLID AND LIQUID PINEAPPLE WASTE

Directory of Open Access Journals (Sweden)

Abdullah Abdullah

2011-07-01

Full Text Available The pineapple waste is contain high concentration of biodegradable organic material and suspended solid. As a result it has a high BOD and extremes of pH conditions. The pineapple wastes juice contains mainly sucrose, glucose, fructose and other nutrients. The characterisation this waste is needed to reduce it by  recycling to get raw material or  for  conversion into useful product of higher value added products such as organic acid, methane , ethanol, SCP and enzyme. Analysis of sugar indicates that liquid waste contains mainly sucrose, glucose and fructose.  The dominant sugar was fructose, glucose and sucrose.  The fructose and glucose levels were similar to each other, with fructose usually slightly higher than glucose. The total sugar and citric acid content were 73.76 and 2.18 g/l. The sugar content in solid waste is glucose and fructose was 8.24 and 12.17 %, no sucrose on this waste

How are macroinvertebrates of slow flowing lotic systems directly affected by suspended and deposited sediments?

Energy Technology Data Exchange (ETDEWEB)

Kefford, Ben J., E-mail: ben.kefford@rmit.edu.a [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Zalizniak, Liliana [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Dunlop, Jason E. [Department of Environment and Resource Management (DERM), 120 Meiers Rd, Indooroopilly, Queensland 4068 (Australia); Smart Water Research Facility, Griffith University, Queensland (Australia); Nugegoda, Dayanthi [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Choy, Satish C. [Department of Environment and Resource Management (DERM), 120 Meiers Rd, Indooroopilly, Queensland 4068 (Australia)

2010-02-15

The effects of suspended and deposited sediments on the macroinvertebrates are well documented in upland streams but not in slower flowing lowland rivers. Using species found in lowland lotic environments, we experimentally evaluate mechanisms for sediments to affect macroinvertebrates, and in one experiment whether salinity alters the effect of suspended sediments. Suspended kaolin clay reduced feeding of Ischnura heterosticta (Odonata: Coenagrionidae) at high turbidity (1000-1500 NTU) but had no effects on feeding of Hemianax papuensis (Odonata: Aeshnidae) and Micronecta australiensis (Hemiptera: Corixidae). In freshwater (0.1 mS/cm), survival of Ischnura aurora was poor in clear water, but improved with suspended kaolin. Growth and feeding of I. aurora were unaffected by suspended sediments and salinity. Burial (1-5 mm) of eggs with kaolin or sand reduced hatching in Physa acuta (Gastropoda: Physidae), Gyraulus tasmanica (Gastropoda: Planorbidae) and Chironomus cloacalis (Diptera: Chironomidae). Settling sediments may pose greater risk to lowland lotic invertebrates than suspended sediments. - Sediment deposition may be more directly detrimental to macroinvertebrates of lowland rivers than suspended sediments.

Evaluation of Spinacia oleracea L. leaves mucilage as an innovative suspending agent

Directory of Open Access Journals (Sweden)

Amit Kumar Nayak

2010-01-01

Full Text Available The present study was undertaken to evaluate the mucilage isolated from Spinacia oleracea L. leaves, commonly named spinach (family: Amaranthaceae as an innovative suspending agent. Zinc oxide suspensions (20% w/v were prepared using the mucilage of S. oleracea L. leaves as a suspending agent, and it was evaluated for its stability by using parameters like, sedimentation profile, degree of flocculation, and redispersibility. The effect of the tested mucilage on the suspension was compared with various commonly used suspending agents, such as, tragacanth, bentonite, and sodium carboxymethyl cellulose (NaCMC at concentrations of 0.5, 1.0, and 2.0% w/v. The results obtained indicated that the mucilage of S. oleracea L. leaves could be used as a suspending agent, and the performance was found to be superior to both tragacanth and bentonite.

Evaluation of Spinacia oleracea L. leaves mucilage as an innovative suspending agent

Science.gov (United States)

Nayak, Amit Kumar; Pal, Dilipkumar; Pany, Dipti Ranjan; Mohanty, Biswaranjan

2010-01-01

The present study was undertaken to evaluate the mucilage isolated from Spinacia oleracea L. leaves, commonly named spinach (family: Amaranthaceae) as an innovative suspending agent. Zinc oxide suspensions (20% w/v) were prepared using the mucilage of S. oleracea L. leaves as a suspending agent, and it was evaluated for its stability by using parameters like, sedimentation profile, degree of flocculation, and redispersibility. The effect of the tested mucilage on the suspension was compared with various commonly used suspending agents, such as, tragacanth, bentonite, and sodium carboxymethyl cellulose (NaCMC) at concentrations of 0.5, 1.0, and 2.0% w/v. The results obtained indicated that the mucilage of S. oleracea L. leaves could be used as a suspending agent, and the performance was found to be superior to both tragacanth and bentonite. PMID:22247868

Studying Suspended Sediment Mechanism with Two-Phase PIV

Science.gov (United States)

Matinpour, H.; Atkinson, J. F.; Bennett, S. J.; Guala, M.

2017-12-01

Suspended sediment transport affects soil erosion, agriculture and water resources quality. Turbulent diffusion is the most primary force to maintain sediments in suspension. Although extensive previous literature have been studying the interactions between turbulent motion and suspended sediment, mechanism of sediments in suspension is still poorly understood. In this study, we investigate suspension of sediments as two distinct phases: one phase of sediments and another phase of fluid with turbulent motions. We designed and deployed a state-of-the-art two-phase PIV measurement technique to discriminate these two phases and acquire velocities of each phase separately and simultaneously. The technique that we have developed is employing a computer-vision based method, which enables us to discriminate sediment particles from fluid tracer particles based on two thresholds, dissimilar particle sizes and different particle intensities. Results indicate that fluid turbulence decreases in the presence of suspended sediments. Obtaining only sediment phase consecutive images enable us to compute fluctuation sediment concentration. This result enlightens understanding of complex interaction between the fluctuation velocities and the fluctuation of associated mass and compares turbulent viscosity with turbulent eddy diffusivity experimentally.

Swing damped movement of suspended objects

International Nuclear Information System (INIS)

Jones, J.F.; Petterson, B.J.; Werner, J.C.

1990-01-01

Transportation of large objects such as nuclear waste shipping casks using overhead cranes can induce pendular motion of the object. Residual oscillation from transportation typically must be damped or allowed to decay before the next process can take place. By properly programming the acceleration of the transporting device (e.g., crane) an oscillation damped transport and swing free stop are obtainable. This report reviews the theory associated with formulating such oscillation damped trajectories for a simply suspended object (e.g., simple pendulum). In addition, the use of force servo damping to eliminate initial oscillation of simply suspended objects is discussed. This is often needed to provide a well defined initial state for the system prior to executing an oscillation damped move. Also included are descriptions of experiments using a CIMCORP XR6100 gantry robot and results from these experiments. Finally, sources of error resulting in small residual oscillations are identified and possible solutions presented

USING TURBIDITY DATA TO PREDICT SUSPENDED SEDIMENT CONCENTRATIONS: POSSIBILITIES, LIMITATIONS, AND PITFALLS

Science.gov (United States)

This talk will look at the relationships between turbidity and suspended sediment concentrations in a variety of geographic areas, geomorphic river types, and river sizes; and attempt to give guidance on using existing turbidity data to predict suspended sediment concentrations.

Prevention of solids formation: Results of the FY 1999 studies

International Nuclear Information System (INIS)

Hunt, R.D.; Beahm, E.C.; Chase, C.W.; Collins, J.L.; Dillow, T.A.; Weber, C.F.

1999-01-01

Tank farm operations at Hanford and Savannah River have been adversely affected by unintentional solids formations. At Hanford, a new cross-site transfer line had to be built because nearly all the original transfer lines were no longer operational due to plugs. At Savannah River, operations at its evaporator system were suspended while a plug in the gravity drain line was physically removed at considerable expense. The plugs as Hanford and Savannah River, which have been characterized, were primarily due to sodium phosphate and sodium aluminosilicate, respectively

Colorimetry Technique for Scalable Characterization of Suspended Graphene.

Science.gov (United States)

Cartamil-Bueno, Santiago J; Steeneken, Peter G; Centeno, Alba; Zurutuza, Amaia; van der Zant, Herre S J; Houri, Samer

2016-11-09

Previous statistical studies on the mechanical properties of chemical-vapor-deposited (CVD) suspended graphene membranes have been performed by means of measuring individual devices or with techniques that affect the material. Here, we present a colorimetry technique as a parallel, noninvasive, and affordable way of characterizing suspended graphene devices. We exploit Newton's rings interference patterns to study the deformation of a double-layer graphene drum 13.2 μm in diameter when a pressure step is applied. By studying the time evolution of the deformation, we find that filling the drum cavity with air is 2-5 times slower than when it is purged.

Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2011–13

Science.gov (United States)

Buchanan, Paul A.; Downing-Kunz, Maureen; Schoellhamer, David H.; Shellenbarger, Gregory; Weidich, Kurt

2014-01-01

The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay. The San Francisco Bay area is home to millions of people, and the bay teems with both resident and migratory wildlife, plants, and fish. Fresh water mixes with salt water in the bay, which is subject both to riverine and marine (tides, waves, influx of salt water) influences. To understand this environment, the USGS, along with its partners, has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay. Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which causes gravity driven circulation patterns and stratification in the water column. Turbidity is measured using light-scattering from suspended solids in water, and is used as a surrogate for suspended-sediment concentration (SSC). Suspended sediment often carries adsorbed contaminants; attenuates sunlight in the water column; deposits on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; and deposits in ports and shipping channels, which can necessitate dredging. Dissolved oxygen, which is essential to a healthy ecosystem, is a fundamental indicator of water quality, and its concentration is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay reverse four times a day, and wind direction and intensity typically change on a daily cycle: consequently, salinity, water temperature, suspendedsediment concentration, and dissolvedoxygen concentration vary spatially and temporally throughout the bay, and continuous measurements are needed to observe these changes. The purpose of this fact sheet

Impact of suspended sediments on the survival of seagrass: Halodule pinifolia (Miki den Hartog

Directory of Open Access Journals (Sweden)

Satumanatpan, S.

2006-07-01

Full Text Available The research aimed to study the level of suspended sediments on the survival of Halodule pinifolia (Miki den Hartog. Three experiments were conducted. Broad concentration of suspended sediments covering the level found in nature were employed in the first experiment. The impact concentration of suspended sediments on the survival of H. pinifolia was extended in more detail in the second and third experiments. H. pinifolia was planted by washing off the mud and holding it with a grating. An air pump was used to stir the sediment in suspension during the experiments and necessary water parameters were strictly control. The suspended sediment was spread by siphon and conducted in a period of 30 days for the first and second experiments, and 45 days for the third experiment. The result indicated that suspended sediments with a concentration of 1-64 mg/l had no impact on the survival of H. pinifolia within 30 days. Initially, suspended sediments of 66 mg/l lowered H. pinifolia's survival to 95% at day 30. Concentration of suspended sediments higher than 66 mg/l affected the survival of H. pinifolia. The decreasing survival was noticed during days 20 -25 of the experiment and all died during days 40-45. However, the life span of H. pinifolia, would be very important and might also affect the survival of H. pinifolia after 30 days.

Ballistic magnetotransport in a suspended two-dimensional electron gas with periodic antidot lattices

Energy Technology Data Exchange (ETDEWEB)

Zhdanov, E. Yu., E-mail: zhdanov@isp.nsc.ru; Pogosov, A. G.; Budantsev, M. V.; Pokhabov, D. A.; Bakarov, A. K. [Siberian Branch of the Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics (Russian Federation)

2017-01-15

The magnetoresistance of suspended semiconductor nanostructures with a two-dimensional electron gas structured by periodic square antidot lattices is studied. It is shown that the ballistic regime of electron transport is retained after detaching the sample from the substrate. Direct comparative analysis of commensurability oscillations of magnetoresistance and their temperature dependences in samples before and after suspension is performed. It is found that the temperature dependences are almost identical for non-suspended and suspended samples, whereas significant differences are observed in the nonlinear regime, caused by direct current passage. Commensurability oscillations in the suspended samples are more stable with respect to exposure to direct current, which can be presumably explained by electron–electron interaction enhancement after detaching nanostructures from the high-permittivity substrate.

Long-term continuous acoustical suspended-sediment measurements in rivers - Theory, application, bias, and error

Science.gov (United States)

Topping, David J.; Wright, Scott A.

2016-05-04

It is commonly recognized that suspended-sediment concentrations in rivers can change rapidly in time and independently of water discharge during important sediment‑transporting events (for example, during floods); thus, suspended-sediment measurements at closely spaced time intervals are necessary to characterize suspended‑sediment loads. Because the manual collection of sufficient numbers of suspended-sediment samples required to characterize this variability is often time and cost prohibitive, several “surrogate” techniques have been developed for in situ measurements of properties related to suspended-sediment characteristics (for example, turbidity, laser-diffraction, acoustics). Herein, we present a new physically based method for the simultaneous measurement of suspended-silt-and-clay concentration, suspended-sand concentration, and suspended‑sand median grain size in rivers, using multi‑frequency arrays of single-frequency side‑looking acoustic-Doppler profilers. The method is strongly grounded in the extensive scientific literature on the incoherent scattering of sound by random suspensions of small particles. In particular, the method takes advantage of theory that relates acoustic frequency, acoustic attenuation, acoustic backscatter, suspended-sediment concentration, and suspended-sediment grain-size distribution. We develop the theory and methods, and demonstrate the application of the method at six study sites on the Colorado River and Rio Grande, where large numbers of suspended-sediment samples have been collected concurrently with acoustic attenuation and backscatter measurements over many years. The method produces acoustical measurements of suspended-silt-and-clay and suspended-sand concentration (in units of mg/L), and acoustical measurements of suspended-sand median grain size (in units of mm) that are generally in good to excellent agreement with concurrent physical measurements of these quantities in the river cross sections at

Enhancing liquid-liquid and solid-liquid phase separation by integrating alternating current electrocoagulators with processing and wastewater control systems

International Nuclear Information System (INIS)

Ryan, P.E.; Stanczyk, T.F.

1989-01-01

Coal, pigments, pharmaceutical solids, ceramics, carbon, clays, metallic powders and ores are among the categorical groups of products which are wasted as suspended solids in aqueous-based wash solutions. Phase separation and recovery of these solids by conventional dewatering systems is costly and relatively inefficient. Alternating current can be used to neutralize the electrical charge on fine and ultra-fine particles in aqueous suspensions, and facilitate agglomeration and settling of these particulates without using chemicals while improving recovery efficiencies. This paper provides an overview of the technology and discusses applications and benefits in the areas of in-plant processing, industrial wastewater treatment, site remediation and water purification

International Odra project (IOP) 'Interdisciplinary German Polish studies on the behaviour of pollutants in the Oder system'. Sub project 4: the state of suspended particulate matter in the Odra River system. Final report

Energy Technology Data Exchange (ETDEWEB)

Henning, K.H.; Damke, H.; Kasbohm, J.; Puff, T.; Breitenbach, E.; Theel, O.; Kiessling, A.

2001-05-20

The purpose of the present project was to characterise the pollutant freight of suspended matter and suspended-matter-borne sediments in the Oder river system on the basis of large samples drawn at selected sampling sites. One of the major goals was to assess and draw up a balance of the transport regime of suspended matter between the compartments water, suspended matter and sediments. Special attention was given to the composition and structure of suspended matter as well as to the distribution of trace elements in the various components. Furthermore, the study was intended to provide ecology-related information on the basis of selected biogenic components. Statements on the time course of pollution of estuarine waters and the Baltic Sea by way of the Oder can be derived from a characterisation of current fluviatile solids (suspended matter and suspended-matter-borne sediments) and determination of their quantitative proportions. The following research strategy was derived from these goals: for a characterisation of suspended matter in terms of composition, structure and biogenic origin it is necessary to determine the concentration of suspended matter, its granulometric composition, carbon and sulphur content, biogenic opal content, mineral content, phase composition, metal content, structure of suspended flakes and association of diatoms in the suspended flakes and on the periphyton. [German] Das Vorhaben ist darauf ausgerichtet, den Belastungszustand der Schwebstoffe und schwebstoffbuertigen Sedimente im Oderflusssystem anhand von Grossproben ausgewaehlter Probenahmeorte zu charakterisieren. Ein wesentliches Ziel ist die Beurteilung des Transportregimes der Schwebstoffe zwischen den Kompartimenten Wasser, Schwebstoff und Sediment sowie seine Bilanzierung. Dabei gilt die besondere Aufmerksamkeit der Zusammensetzung und der Struktur der Schwebstoffe sowie die Spurenelementspeziation an die unterschiedlichen Bestandteile. Weiterhin werden oekologische Aussagen

Total Suspended Load and Sediment Yield of Kayan River, Bulungan District, East Kalimantan

Directory of Open Access Journals (Sweden)

Suprapto Dibyosaputro

2016-12-01

Full Text Available This research was carried out the the drainage system of Kayan river, Bulungan District, East Kalimantan. The purpose of the research were to study the physical conditions of the Kayan catchment area, calculate the suspended sediment load, and to define the total sediment yield of Kayan River. Observation method were used in this research both of direct field observation as well as laboratory observation. Data acquired in this study were include of climatic data, geology, geomorphology, soil and land cover data. Besides also rain-fall data, temperature, river discharge and suspended sediment load. The total sediment yield were calculated by mean of mathematical and statistical analysis especially of linier regression analysis. The result of the research show that total the sediment yield of Kayan River with drainage area of 6,329.452 km² is about 236,921.25 m³/km²/year. The interesting result of the statistical analysis was that the existing negative correlation between river discharge and suspended sediment load. It is the effect of the location of discharge and suspended measurement. This condition caused by sea tide effect on river discharge at the apex delta. During high tide water river trend rising up on discharge but not on suspended sediment load. Instead, also existing setting down processes takes places of the suspended sediment load into the river bottom upper stream and the apex.

Self-suspended permanent magnetic FePt ferrofluids

KAUST Repository

Dallas, Panagiotis; Kelarakis, Antonios; Sahore, Ritu; DiSalvo, Francis J.; Livi, Sebastien; Giannelis, Emmanuel P.

2013-01-01

on the surface of L10 FePt nanoparticles. In contrast, all types of ferrofluids previously reported employ either volatile solvents as the suspending media or superparamagnetic iron oxide nanoparticles (that lacks permanent magnetization) as the inorganic

Suspended matter and heavy metal content of the Elbe Estuary

International Nuclear Information System (INIS)

Vollbrecht, K.

1980-01-01

(1) In the River Elbe estuary there is a turbidity zone which is closely bound to the region of brackish waters. Its suspended matter content changes strongly with the tidal rhythm. Suspended matter and river bed sediments influence each other by exchanging their particles. Owing to that mechanism, the heavy metal ions bound or taken up by the suspended matter (sorption) enter the sediments. To obtain an estimation of the estuary's ability to cope with ( self purify ) a strong burden of industrial wastes, it is neccessary to take into consideration the absorbing capacity of both the mean suspension load and the sediments. (2) The concentration of nearly all heavy metal ions investigated in the suspension load decreases remarkably at the very beginning of the turbid zone already, in the Hamburg region. It indicates that the binding process are going on very rapidly and that the metal ion absorbing capacity of the Elbe estuary still requires only the first few miles of this self purification system. The results gained indicate that the suspended matter in Hamburg waters could bind or take up more heavy metal ions than are discharged into this area. (3) The concentration of most ions bound to the suspension material correlates very well with the grain size distribution of the (anorganic) particles. The concentration values decrease along the estuary and lead to a continuous transition to the values of the open sea. Cu, Ni and Cd appear to be captured preferably by organic suspended matter. This behaviour, however, is solely restricted to the turbid zone. In the open sea, after oxidation of the binding organic material, Cu and Ni correspond to the anorganic grain size distribution. (orig./HP) [de

Combinational approach using solid dispersion and semi-solid matrix technology to enhance in vitro dissolution of telmisartan

Directory of Open Access Journals (Sweden)

Syed Faisal Ali

2016-02-01

Full Text Available The present investigation was focused to formulate semi-solid capsules (SSCs of hydrophobic drug telmisartan (TLMS by encapsulating semi-solid matrix of its solid dispersion (SD in HPMC capsules. The combinational approach was used to reduce the lag time in drug release and improvise its dissolution. SDs of TLMS was prepared using hot fusion method by varying the combinations of Pluronic-F68, Gelucire 50/13 and Plasdone S630. A total of nine batches (SD1-SD9 were characterized for micromeritic properties, in vitro dissolution behavior and surface characterization. SD4 with 52.43% cumulative drug release (CDR in phosphate buffer, pH 7.4, in 120 min, t50% 44.2 min and DE30min 96.76% was selected for the development of semi-solid capsules. Differential scanning calorimetry of SD4 revealed molecular dispersion of TLMS in Pluronic-F68. SD4 was formulated into SSCs using Gelucire 44/14 and PEG 400 as semi-solid components and PEG 6000 as a suspending agent to achieve reduction in lag time for effective drug dissolution. SSC6 showed maximum in vitro drug dissolution 97.49 % in phosphate buffer, pH 7.4 with in 20 min that was almost a three folds reduction in the time required to achieve similar dissolution by SD. Thus, SSCs present an excellent approach to enhance in vitro dissolution as well as to reduce the lag time of dissolution for poorly water soluble drugs especially to those therapeutic classes that are intended for faster onset of action. Developed approach based on HPMC capsules provided a better alternative to target delivery of telmisartan to the vegetarian population.

Effect of anabolic steroids on overloaded and overloaded suspended skeletal muscle

Science.gov (United States)

Tsika, R. W.; Herrick, R. E.; Baldwin, K. M.

1987-01-01

The effect of treatment with an anabolic steroid (nandrolone decanoate) on the muscle mass, the subcellular protein content, and the myosin patterns of normal overloaded and suspended overloaded plantaris muscle in female rat was investigated, dividing rats into six groups: normal control (NC), overload (OV), OV steroid (OV-S), normal suspended (N-sus), OV suspended (OV-sus), and OV suspended steroid (OV-sus-S). Relative to control values, overload produced a sparing effect on the muscle weight of the OV-sus group as well as increases of muscle weight of the OV group; increased protein content; and an increased expression of slow myosin in both OV and OV-sus groups. Steroid treatment of OV animals did not after the response of any parameter analyzed for the OV group, but in the OV-sus group steroid treatment induced increases in muscle weight and in protein content of the OV-sus-S group. The treatment did not alter the pattern of isomyosin expression observed in the OV or the OV-sus groups. These result suggest that the steroid acts synergistically with functional overload only under conditions in which the effect of overload is minimized by suspension.

The influence of solid particles density on parameters of multijet insert

Directory of Open Access Journals (Sweden)

Z. Niedźwiedzki

2008-10-01

Full Text Available Some dependences between solid particles density, chosen geometry and exploitation parameters of multijet inserts and developmentof laminar motion in continuous multijet sedimentation process, are presented in this paper. Results are obtained from the analysis of the multijet sedimentation model considering development of laminar motion of the suspension in the multijet insert conduit of the settling tank. The range of the researches covered, in particular, quantities necessary for designing inserts of multijet settling tanks finding application in purifying suspended solids in casting processes. Discussed problem has practical and cognitive meanings and is a base for more efficient designing multijet settling tanks inserts applied in iron and steel industry. Application of most efficient construction and exploitation parameters allows designing devices of lower dimensions what is especially advantageous in casting works.

Transfer-last suspended graphene fabrication on gold, graphite and silicon nanostructures

OpenAIRE

Reynolds, J.; Boodhoo, L.; Huang, C.C.; Hewak, D.W.; Saito, S.; Tsuchiya, Y.; Mizuta, H.

2015-01-01

While most graphene devices fabricated so far have been by transferring graphene onto flat substrates first, an interesting approach would be to transfer graphene onto patterned substrates to suspend graphene for future graphene nanoelectromechanical device applications. This novel "transfer-last" fabrication is beneficial for reducing possible damage of the suspended graphene caused by subsequent undercutting processes and typical substrate interactions. On the other hand, reduction of conta...

Geospatial approach towards enumerative analysis of suspended sediment concentration for Ganges-Brahmaputra Bay

Science.gov (United States)

Pandey, Palak; Kunte, Pravin D.

2016-10-01

This study presents an easy, modular, user-friendly, and flexible software package for processing of Landsat 7 ETM and Landsat 8 OLI-TIRS data for estimating suspended particulate matter concentrations in the coastal waters. This package includes 1) algorithm developed using freely downloadable SCILAB package, 2) ERDAS Models for iterative processing of Landsat images and 3) ArcMAP tool for plotting and map making. Utilizing SCILAB package, a module is written for geometric corrections, radiometric corrections and obtaining normalized water-leaving reflectance by incorporating Landsat 8 OLI-TIRS and Landsat 7 ETM+ data. Using ERDAS models, a sequence of modules are developed for iterative processing of Landsat images and estimating suspended particulate matter concentrations. Processed images are used for preparing suspended sediment concentration maps. The applicability of this software package is demonstrated by estimating and plotting seasonal suspended sediment concentration maps off the Bengal delta. The software is flexible enough to accommodate other remotely sensed data like Ocean Color monitor (OCM) data, Indian Remote Sensing data (IRS), MODIS data etc. by replacing a few parameters in the algorithm, for estimating suspended sediment concentration in coastal waters.

Fatigue Performance Assessment of Composite Arch Bridge Suspenders Based on Actual Vehicle Loads

Directory of Open Access Journals (Sweden)

Bin Chen

2015-01-01

Full Text Available In the through arch bridges, the suspenders are the key components connecting the arch rib and the bridge deck in the middle, and their safety is an increasing focus in the field of bridge engineering. In this study, various vehicle traffic flow parameters are investigated based on the actual vehicle data acquired from the long-term structural health monitoring system of a composite arch bridge. The representative vehicle types and the probability density functions of several parameters are determined, including the gross vehicle weight, axle weight, time headway, and speed. A finite element model of the bridge structure is constructed to determine the influence line of the cable force for various suspenders. A simulated vehicle flow, generated using the Monte Carlo method, is applied on the influence lines of the target suspender to determine the stress process, and then the stress amplitude spectrum is obtained based on the statistical analysis of the stress process using the rainflow counting method. The fatigue performance levels of various suspenders are analyzed according to the Palmgren-Miner linear cumulative damage theory, which helps to manage the safety of the suspenders.

Suspended dust in Norwegian cities

International Nuclear Information System (INIS)

2001-01-01

According to calculations, at least 80 000 people in Oslo and 8 000 in Trondheim were annoyed by too much suspended dust in 2000. The dust concentration is greatest in the spring, presumably because dust is swirling up from melting snow and ice on the streets. Car traffic is the main source of the dust, except for some of the most highly exposed regions where wood-firing from old stoves contributes up to 70 percent of the dust. National targets for air quality include suspended dust, nitrogen dioxide, sulphur dioxide and benzene. Calculations show that nitrogen dioxide emissions exceeding the limit affected 4 000 people in Oslo and 1 000 people in Trondheim. The sulphur dioxide emissions in the major cities did non exceed the national quality limit; they did exceed the limit in some of the smaller industrial centres. In Trondheim, measurements show that the national limit for benzene was exceeded. Most of the emission of nitrogen dioxide comes from the road traffic. Local air pollution at times causes considerable health- and well-being problems in the larger cities and industrial centres, where a great part of the population may be at risk of early death, infection of the respiratory passage, heart- and lung diseases and cancer

Infrared Spectroscopy of HNO and Noh Suspended in Solid Parahydrogen

Science.gov (United States)

Anderson, David T.; Ruzi, Mahmut

2013-06-01

The only report in the literature on the infrared spectroscopy of the parent oxynitrene NOH was performed using Ar matrix isolation spectroscopy at 10 K. In this previous study, the NOH is synthesized by co-deposition of NO/Ar and a H_2/Ar mixture that is passed through a microwave discharge to create H-atoms. The H-atoms recombine with NO in the Ar matrix to produce mostly HNO, but some NOH is produced as well. In this work we irradiate NO doped parahydrogen solids at 2 K using 193 nm radiation which is known to generate H-atoms as by-products. After the photolysis laser is stopped, we detect growth of HNO and NOH presumably due to reactions of H-atoms with NO analogous to the previous Ar matrix study. The higher energy NOH isomer is predicted by high-level calculations to be in a triplet ground electronic state. Interestingly, the infrared absorptions of NOH for the two observed vibrational modes (bend and OH stretch) display fine structure; an intense central peak with smaller peaks spaced symmetrically to both lower and higher wavenumbers. Further, the spacing between the peaks is the same for both vibrational modes. We believe this fine structure reflects the zero-field splitting of the triplet ground state of NOH (magnetic dipole-dipole interaction) and our most current results and analysis will be presented. G. Maier, H. P. Reisenauer, M. De Marco, Angew. Chem. Int. Ed. 38, 108-110 (1999). M. Fushitani and T. Momose, Low Temp. Phys. 29, 740-743 (2003). U. Bozkaya, J. M. Turney, Y. Yamaguchi, and H. F. Schaefer III, J. Chem. Phys. 136, 164303 (2012).

Capturing Flow-weighted Water and Suspended Particulates from Agricultural Canals During Drainage Events.

Science.gov (United States)

Bhadha, Jehangir H; Sexton, Anne; Lang, Timothy A; Daroub, Samira H

2017-11-07

The purpose of this study is to describe the methods used to capture flow-weighted water and suspended particulates from farm canals during drainage discharge events. Farm canals can be enriched by nutrients such as phosphorus (P) that are susceptible to transport. Phosphorus in the form of suspended particulates can significantly contribute to the overall P loads in drainage water. A settling tank experiment was conducted to capture suspended particulates during discrete drainage events. Farm canal discharge water was collected in a series of two 200 L settling tanks over the entire duration of the drainage event, so as to represent a composite subsample of the water being discharged. Imhoff settling cones are ultimately used to settle out the suspended particulates. This is achieved by siphoning water from the settling tanks via the cones. The particulates are then collected for physico-chemical analyses.

Sediment acoustic index method for computing continuous suspended-sediment concentrations

Science.gov (United States)

Landers, Mark N.; Straub, Timothy D.; Wood, Molly S.; Domanski, Marian M.

2016-07-11

Suspended-sediment characteristics can be computed using acoustic indices derived from acoustic Doppler velocity meter (ADVM) backscatter data. The sediment acoustic index method applied in these types of studies can be used to more accurately and cost-effectively provide time-series estimates of suspended-sediment concentration and load, which is essential for informed solutions to many sediment-related environmental, engineering, and agricultural concerns. Advantages of this approach over other sediment surrogate methods include: (1) better representation of cross-sectional conditions from large measurement volumes, compared to other surrogate instruments that measure data at a single point; (2) high temporal resolution of collected data; (3) data integrity when biofouling is present; and (4) less rating curve hysteresis compared to streamflow as a surrogate. An additional advantage of this technique is the potential expansion of monitoring suspended-sediment concentrations at sites with existing ADVMs used in streamflow velocity monitoring. This report provides much-needed standard techniques for sediment acoustic index methods to help ensure accurate and comparable documented results.

Effect of mixed liquor volatile suspended solids (MLVSS and hydraulic retention time (HRT on the performance of activated sludge process during the biotreatment of real textile wastewater

Directory of Open Access Journals (Sweden)

Kapil Kumar

2014-03-01

Full Text Available Adequate information is available on colour and organics removal in batch mode using pure microbial cultures from dye contaminated wastewater. There was a need to develop environment friendly and cost effective treatment technique for actual field conditions. Therefore, the present study was undertaken with an aim to evaluate the potential of acclimatized mixed microbial consortia for the removal of colour and organics from real textile wastewater. Experiments were performed in laboratory scale activated sludge process (ASP unit under steady state condition, varying mixed liquor volatile suspended solids (MLVSS (2500, 3500 and 5000 mg/l and hydraulic retention time (HRT (18, 24 and 36 h. The results showed that decolourization and chemical oxygen demand (COD removal increased with increase in MLVSS and HRT. At 18 h HRT, decolourization was found to be 46, 54 and 67%, which increased to 67, 75 and 90% (36 h HRT at 2500, 3500 and 5000 mg/l MLVSS, respectively. COD removal was found to be 62, 73 and 77% (at 18 h HRT which increased to 77, 85 and 91% (36 h HRT at 2000, 3500 and 5000 mg/l MLVSS, respectively. On the basis of the results obtained in this study suitable treatment techniques can be developed for the treatment of wastewater contaminated with variety of dyes in continuous mode of operation. This shall have the advantage of treatment of larger quantity of wastewater in shorter duration.

Piezoresistance of top-down suspended Si nanowires

International Nuclear Information System (INIS)

Koumela, A; Mercier, D; Dupre, C; Jourdan, G; Marcoux, C; Ollier, E; Duraffourg, L; Purcell, S T

2011-01-01

Measurements of the gauge factor of suspended, top-down silicon nanowires are presented. The nanowires are fabricated with a CMOS compatible process and with doping concentrations ranging from 2 x 10 20 down to 5 x 10 17 cm -3 . The extracted gauge factors are compared with results on identical non-suspended nanowires and with state-of-the-art results. An increase of the gauge factor after suspension is demonstrated. For the low doped nanowires a value of 235 is measured. Particular attention was paid throughout the experiments to distinguishing real resistance change due to strain modulation from resistance fluctuations due to charge trapping. Furthermore, a numerical model correlating surface charge density with the gauge factor is presented. Comparison of the simulations with experimental measurements shows the validity of this approach. These results contribute to a deeper understanding of the piezoresistive effect in Si nanowires.

Computing time-series suspended-sediment concentrations and loads from in-stream turbidity-sensor and streamflow data

Science.gov (United States)

Rasmussen, Patrick P.; Gray, John R.; Glysson, G. Doug; Ziegler, Andrew C.

2010-01-01

Over the last decade, use of a method for computing suspended-sediment concentration and loads using turbidity sensors—primarily nephelometry, but also optical backscatter—has proliferated. Because an in- itu turbidity sensor is capa le of measuring turbidity instantaneously, a turbidity time series can be recorded and related directly to time-varying suspended-sediment concentrations. Depending on the suspended-sediment characteristics of the measurement site, this method can be more reliable and, in many cases, a more accurate means for computing suspended-sediment concentrations and loads than traditional U.S. Geological Survey computational methods. Guidelines and procedures for estimating time s ries of suspended-sediment concentration and loading as a function of turbidity and streamflow data have been published in a U.S. Geological Survey Techniques and Methods Report, Book 3, Chapter C4. This paper is a summary of these guidelines and discusses some of the concepts, s atistical procedures, and techniques used to maintain a multiyear suspended sediment time series.

Influence of Wheel Eccentricity on Vertical Vibration of Suspended Monorail Vehicle: Experiment and Simulation

OpenAIRE

Kaikai Lv; Kaiyun Wang; Zhihui Chen; Chengbiao Cai; Lirong Guo

2017-01-01

This paper investigates the influence of wheel eccentricity on vertical vibration of suspended monorail vehicle based on experiment and simulation. Two sets of tests are conducted in the first Chinese suspended monorail, and the tested acceleration is analyzed and exhibited. A multibody dynamic model of the suspended monorail vehicle is established to simulate the vertical vibration of car body excited by wheel eccentricity. The results show that there are three factors which may cause an abn...

The Ages in a Self-Suspended Nanoparticle Liquid

KAUST Repository

Agarwal, Praveen; Qi, Haibo; Archer, Lynden A.

2010-01-01

Telomers ionically tethered to nanometer-sized particles yield self-suspended, nanoparticle-Iaden liquids with unusual dynamical features. By subjecting these suspensions to controlled, modest shear strains, we find that their flow behaviors

Magnetically suspended railway

Energy Technology Data Exchange (ETDEWEB)

Guenther, C

1977-07-28

The invention concerns the emergency support of a magnetically suspended railway. On failure of the magnetic suspension/tracking system, the vehicles touch down on the rail configuration by means of emergency gliding elements like sliding shoes, skids, or the like. In doing this, the touch-down shock of the emergency gliding elements has to be limited to a force maximum as small as possible. According to the invention a spring-attenuator combination is used for this purpose, the spring characteristic being linear while the attenuator has a square-law characteristic for the compressing and a linear characteristic for the yielding motion. The force maximum thus achieved is exactly half the size of the physically smallest possible force maximum for an emergency gliding element springed without damping.

Superior thermal conductivity in suspended bilayer hexagonal boron nitride

Science.gov (United States)

Wang, Chengru; Guo, Jie; Dong, Lan; Aiyiti, Adili; Xu, Xiangfan; Li, Baowen

2016-01-01

We reported the basal-plane thermal conductivity in exfoliated bilayer hexagonal boron nitride h-BN that was measured using suspended prepatterned microstructures. The h-BN sample suitable for thermal measurements was fabricated by dry-transfer method, whose sample quality, due to less polymer residues on surfaces, is believed to be superior to that of PMMA-mediated samples. The measured room temperature thermal conductivity is around 484 Wm−1K−1(+141 Wm−1K−1/ −24 Wm−1K−1) which exceeds that in bulk h-BN, providing experimental observation of the thickness-dependent thermal conductivity in suspended few-layer h-BN. PMID:27142571

Resonant tunnelling features in a suspended silicon nanowire single-hole transistor

Energy Technology Data Exchange (ETDEWEB)

Llobet, Jordi; Pérez-Murano, Francesc, E-mail: francesc.perez@csic.es, E-mail: z.durrani@imperial.ac.uk [Institut de Microelectrònica de Barcelona (IMB-CNM CSIC), Campus UAB, E-08193 Bellaterra, Catalonia (Spain); Krali, Emiljana; Wang, Chen; Jones, Mervyn E.; Durrani, Zahid A. K., E-mail: francesc.perez@csic.es, E-mail: z.durrani@imperial.ac.uk [Department of Electrical and Electronic Engineering, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom); Arbiol, Jordi [Institució Catalana de Recerca i Estudis Avançats (ICREA) and Institut Català de Nanociència i Nanotecnologia (ICN2), Campus UAB, 08193 Bellaterra, Catalonia (Spain); CELLS-ALBA Synchrotron Light Facility, 08290 Cerdanyola, Catalonia (Spain)

2015-11-30

Suspended silicon nanowires have significant potential for a broad spectrum of device applications. A suspended p-type Si nanowire incorporating Si nanocrystal quantum dots has been used to form a single-hole transistor. Transistor fabrication uses a novel and rapid process, based on focused gallium ion beam exposure and anisotropic wet etching, generating <10 nm nanocrystals inside suspended Si nanowires. Electrical characteristics at 10 K show Coulomb diamonds with charging energy ∼27 meV, associated with a single dominant nanocrystal. Resonant tunnelling features with energy spacing ∼10 meV are observed, parallel to both diamond edges. These may be associated either with excited states or hole–acoustic phonon interactions, in the nanocrystal. In the latter case, the energy spacing corresponds well with reported Raman spectroscopy results and phonon spectra calculations.

Noise Performance of a 72 m Suspended FABRY-PÉROT Cavity

Science.gov (United States)

Dumas, Jean-Charles; Ju, Li; Barriga, Pablo; Zhao, Chunnong; Woolley, Andrew A.; Blair, David G.

We report on a seismic isolator with a relatively compact 3 m stack, combining new passive isolation techniques. It consists of three cascaded passive 3D isolator stages suspended from an Ultra Low Frequency (ULF) horizontal Robert linkage stage which itself is suspended from a ULF 3D pre-isolator. The 3D isolators use self-damping pendulums and Euler springs for the horizontal and vertical stages respectively, while the 3D pre-isolator is the combination of an inverse pendulum which provides low frequency horizontal pre-isolation, and a LaCoste linkage for low frequency vertical pre-isolation. Two isolators suspending mirror test masses have been built to form a 72 m optical cavity in order to test their performance. We report results which demonstrate residual motion at nanometer level at frequencies above 1 Hz.

Resonant tunnelling features in a suspended silicon nanowire single-hole transistor

International Nuclear Information System (INIS)

Llobet, Jordi; Pérez-Murano, Francesc; Krali, Emiljana; Wang, Chen; Jones, Mervyn E.; Durrani, Zahid A. K.; Arbiol, Jordi

2015-01-01

Suspended silicon nanowires have significant potential for a broad spectrum of device applications. A suspended p-type Si nanowire incorporating Si nanocrystal quantum dots has been used to form a single-hole transistor. Transistor fabrication uses a novel and rapid process, based on focused gallium ion beam exposure and anisotropic wet etching, generating <10 nm nanocrystals inside suspended Si nanowires. Electrical characteristics at 10 K show Coulomb diamonds with charging energy ∼27 meV, associated with a single dominant nanocrystal. Resonant tunnelling features with energy spacing ∼10 meV are observed, parallel to both diamond edges. These may be associated either with excited states or hole–acoustic phonon interactions, in the nanocrystal. In the latter case, the energy spacing corresponds well with reported Raman spectroscopy results and phonon spectra calculations

40 CFR 1042.330 - Selling engines from an engine family with a suspended certificate of conformity.

Science.gov (United States)

2010-07-01

... with a suspended certificate of conformity. 1042.330 Section 1042.330 Protection of Environment... engines from an engine family with a suspended certificate of conformity. You may sell engines that you produce after we suspend the engine family's certificate of conformity under § 1042.315 only if one of the...

Pulse Jet Mixing Tests With Noncohesive Solids

Energy Technology Data Exchange (ETDEWEB)

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael K.; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro

2012-02-17

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid. The tests were conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants, and the test data were used to develop models predicting two measures of mixing performance for full-scale WTP vessels. The models predict the cloud height (the height to which solids will be lifted by the PJM action) and the critical suspension velocity (the minimum velocity needed to ensure all solids are suspended off the floor, though not fully mixed). From the cloud height, the concentration of solids at the pump inlet can be estimated. The predicted critical suspension velocity for lifting all solids is not precisely the same as the mixing requirement for 'disturbing' a sufficient volume of solids, but the values will be similar and closely related. These predictive models were successfully benchmarked against larger scale tests and compared well with results from computational fluid dynamics simulations. The application of the models to assess mixing in WTP vessels is illustrated in examples for 13 distinct designs and selected operational conditions. The values selected for these examples are not final; thus, the estimates of performance should not be interpreted as final conclusions of design adequacy or inadequacy. However, this work does reveal that several vessels may require adjustments to design, operating features, or waste feed properties to ensure confidence in operation. The models described in this report will prove to be valuable engineering tools to evaluate options as designs are finalized for the WTP. Revision 1 refines data sets used for model development and summarizes models developed since the completion of Revision 0.

Nuclear reactor with a suspended vessel

International Nuclear Information System (INIS)

Lemercier, Guy.

1977-01-01

This invention relates to a nuclear reactor with a suspended vessel and applies in particular when this is a fast reactor, the core or active part of the reactor being inside the vessel and immersed under a suitable volume of flowing liquid metal to cool it by extracting the calories released by the nuclear fission in the fuel assemblies forming this core [fr

Impact of robotics and a suspended lead suit on physician radiation exposure during percutaneous coronary intervention

Energy Technology Data Exchange (ETDEWEB)

Madder, Ryan D., E-mail: ryan.madder@spectrumhealth.org; VanOosterhout, Stacie; Mulder, Abbey; Elmore, Matthew; Campbell, Jessica; Borgman, Andrew; Parker, Jessica; Wohns, David

2017-04-15

Background: Reports of left-sided brain malignancies among interventional cardiologists have heightened concerns regarding physician radiation exposure. This study evaluated the impact of a suspended lead suit and robotic system on physician radiation exposure during percutaneous coronary intervention (PCI). Methods: Real-time radiation exposure data were prospectively collected from dosimeters worn by operating physicians at the head- and chest-level during consecutive PCI cases. Exposures were compared in three study groups: 1) manual PCI performed with traditional lead apparel; 2) manual PCI performed using suspended lead; and 3) robotic PCI performed in combination with suspended lead. Results: Among 336 cases (86.6% manual, 13.4% robotic) performed over 30 weeks, use of suspended lead during manual PCI was associated with significantly less radiation exposure to the chest and head of operating physicians than traditional lead apparel (chest: 0.0 [0.1] μSv vs 0.4 [4.0] μSv, p < 0.001; head: 0.5 [1.9] μSv vs 14.9 [51.5] μSv, p < 0.001). Chest-level radiation exposure during robotic PCI performed in combination with suspended lead was 0.0 [0.0] μSv, which was significantly less chest exposure than manual PCI performed with traditional lead (p < 0.001) or suspended lead (p = 0.046). In robotic PCI the median head-level exposure was 0.1 [0.2] μSv, which was 99.3% less than manual PCI performed with traditional lead (p < 0.001) and 80.0% less than manual PCI performed with suspended lead (p < 0.001). Conclusions: Utilization of suspended lead and robotics were observed to result in significantly less radiation exposure to the chest and head of operating physicians during PCI. - Highlights: • Use of suspended lead during manual PCI reduced cranial radiation among operators by 97%. • Robotic PCI reduced cranial radiation among operators by 99%. • Suspended lead and robotics together achieved the lowest levels of radiation exposure.

Impact of robotics and a suspended lead suit on physician radiation exposure during percutaneous coronary intervention

International Nuclear Information System (INIS)

Madder, Ryan D.; VanOosterhout, Stacie; Mulder, Abbey; Elmore, Matthew; Campbell, Jessica; Borgman, Andrew; Parker, Jessica; Wohns, David

2017-01-01

Background: Reports of left-sided brain malignancies among interventional cardiologists have heightened concerns regarding physician radiation exposure. This study evaluated the impact of a suspended lead suit and robotic system on physician radiation exposure during percutaneous coronary intervention (PCI). Methods: Real-time radiation exposure data were prospectively collected from dosimeters worn by operating physicians at the head- and chest-level during consecutive PCI cases. Exposures were compared in three study groups: 1) manual PCI performed with traditional lead apparel; 2) manual PCI performed using suspended lead; and 3) robotic PCI performed in combination with suspended lead. Results: Among 336 cases (86.6% manual, 13.4% robotic) performed over 30 weeks, use of suspended lead during manual PCI was associated with significantly less radiation exposure to the chest and head of operating physicians than traditional lead apparel (chest: 0.0 [0.1] μSv vs 0.4 [4.0] μSv, p < 0.001; head: 0.5 [1.9] μSv vs 14.9 [51.5] μSv, p < 0.001). Chest-level radiation exposure during robotic PCI performed in combination with suspended lead was 0.0 [0.0] μSv, which was significantly less chest exposure than manual PCI performed with traditional lead (p < 0.001) or suspended lead (p = 0.046). In robotic PCI the median head-level exposure was 0.1 [0.2] μSv, which was 99.3% less than manual PCI performed with traditional lead (p < 0.001) and 80.0% less than manual PCI performed with suspended lead (p < 0.001). Conclusions: Utilization of suspended lead and robotics were observed to result in significantly less radiation exposure to the chest and head of operating physicians during PCI. - Highlights: • Use of suspended lead during manual PCI reduced cranial radiation among operators by 97%. • Robotic PCI reduced cranial radiation among operators by 99%. • Suspended lead and robotics together achieved the lowest levels of radiation exposure.

Intermittent Ozonation to Reduce Excess Biological Sludge in SBR

Directory of Open Access Journals (Sweden)

Afshin Takdastan

2009-09-01

Full Text Available A combination of ozonation and an aerobic biological process such as the activated sludge has been recently developed as an alternative solution for sludge reduction with the objective of minimizing the excess biological sludge production. In this study, two SBR reactors each with a capacity of 20 liters and controlled by an on-line system are used. Once the steady state conditions were set in the reactors, sampling and testing of such parameters as COD, MLSS, MLVSS, DO, SOUR, SVI, residual ozone, and Y coefficient were performed over the 8 months of research. Results showed that during the solid retention time of 10 days, the kinetic coefficients of Y and Kd were 0.58 mg biomass/mg COD and 0.058 1/day, respectively. In the next stage of the study, different concentrations of ozone in the reactor were intermittently used to reduce the excess biological sludge production. The results showed that 22 mg of ozone per 1 gram of MLSS in the reactor was able to reduce the yield coefficient Y from 0.58 to 0.23 mg Biomass/mg COD. In other words, the excess biological sludge reduced by 60% but the soluble COD increased slightly in the effluent and the removal percentage decreased from 92 in the blank reactor to 76 in the test reactor. While the amount of SVI and SOUR for this level of ozone concentration reached 6 mgO2/h.gVSS and 27 ml/g, respectively. No excess sludge was observed in the reactor for an ozone concentration of 27 mg per 1 gram of MLSS.

Urban social assistance in China : Transnational diffusion and national interpretation

NARCIS (Netherlands)

Liu, Tao; Sun, L.

2016-01-01

In 1999 the State Council of the People’s Republic of China (PRC) introduced the Regulation on the Minimum Living Standard Scheme (MLSS, or dibao) for urban residents in China. Policy learning from different parts of the world significantly shaped the formation and expansion of the MLSS, and

Large theoretical thermoelectric power factor of suspended single-layer MoS2

International Nuclear Information System (INIS)

Babaei, Hasan; Khodadadi, J. M.; Sinha, Sanjiv

2014-01-01

We have calculated the semi-classical thermoelectric power factor of suspended single-layer (SL)- MoS 2 utilizing electron relaxation times derived from ab initio calculations. Measurements of the thermoelectric power factor of SL-MoS 2 on substrates reveal poor power factors. In contrast, we find the thermoelectric power factor of suspended SL-MoS 2 to peak at ∼2.8 × 10 4 μW/m K 2 at 300 K, at an electron concentration of 10 12 cm −2 . This figure is higher than that in bulk Bi 2 Te 3 , for example. Given its relatively high thermal conductivity, suspended SL-MoS 2 may hold promise for in-plane thin-film Peltier coolers, provided reasonable mobilities can be realized

[Effect of suspended silt from dredging at Yangtze estuary on Brachionus plicatilis].

Science.gov (United States)

Wang, Jinqui; Xu, Zhaoli; Shi, Chun; Chen, Yaqu

2002-07-01

The effect of suspended silt from dredging at Yangtze estuary on Brachionus plicatilis was investigated by clonal culture (to construct life table) and population accumulative culture. The intrinsic increasing rate of the rotifer population was greatly reduced under different concentrations (1, 3, 5, 7 and 9 mg.ml-1) of silt, from 29.6% to 64.1%, and to a maximum of 130.0%. The suspended silt affected population survival rate, rather than its reproduction rate. In accumulative culture, the densities of female, males, parthenogenetic eggs, and resting eggs in the population were not affected by silt. It was concluded that the presence of suspended silt should have a certain negative influence on the rotifer population in dredging Yangtze estuary.

Vertical transport of suspended particulate trace elements in the North Atlantic Ocean

International Nuclear Information System (INIS)

Kuss, J.; Kremling, K.; Scholten, J.

1999-01-01

Suspended marine particles play a key role in the exchange processes between rapidly sinking particles and seawater because of their large surface area and long residence times. They are involved in the transport processes of rapidly sinking particles (∼ 100 m/day) through aggregation and disaggregation. This mechanism results in a net downward transport of suspended particulate trace elements (TE). To provide more information to these processes TE in suspended particulate material (SPM) have been measured on three cruises from 1995 to 1997 along 20 deg. W using a large volume in situ filtration between 25 m and 4150 m depth in addition to particle flux measurements with sediment traps. These studies were performed under the framework of German JGOFS

Biohydrogen production in the suspended and attached microbial growth systems from waste pastry hydrolysate.

Science.gov (United States)

Han, Wei; Hu, Yunyi; Li, Shiyi; Li, Feifei; Tang, Junhong

2016-10-01

Waste pastry was hydrolyzed by glucoamylase and protease which were obtained from solid state fermentation of Aspergillus awamori and Aspergillus oryzae to produce waste pastry hydrolysate. Then, the effects of hydraulic retention times (HRTs) (4-12h) on hydrogen production rate (HPR) in the suspended microbial growth system (continuous stirred tank reactor, CSTR) and attached microbial growth system (continuous mixed immobilized sludge reactor, CMISR) from waste pastry hydrolysate were investigated. The maximum HPRs of CSTR (201.8mL/(h·L)) and CMISR (255.3mL/(h·L)) were obtained at HRT of 6h and 4h, respectively. The first-order reaction could be used to describe the enzymatic hydrolysis of waste pastry. The carbon content of the waste pastry remained 22.8% in the undigested waste pastry and consumed 77.2% for carbon dioxide and soluble microbial products. To our knowledge, this is the first study which reports biohydrogen production from waste pastry. Copyright © 2016 Elsevier Ltd. All rights reserved.

78 FR 22501 - Designation of Areas for Air Quality Planning Purposes; State of Nevada; Total Suspended Particulate

Science.gov (United States)

2013-04-16

... Areas for Air Quality Planning Purposes; State of Nevada; Total Suspended Particulate AGENCY... designations for total suspended particulate within the State of Nevada because the designations are no longer necessary. These designations relate to the attainment or unclassifiable areas for total suspended...

Response of reef corals on a fringing reef flat to elevated suspended-sediment concentrations: Moloka‘i, Hawai‘i

Science.gov (United States)

Jokiel, Paul L.; Rodgers, Ku'ulei S.; Storlazzi, Curt D.; Field, Michael E.; Lager, Claire V.; Lager, Dan

2014-01-01

A long-term (10 month exposure) experiment on effects of suspended sediment on the mortality, growth, and recruitment of the reef corals Montipora capitata and Porites compressa was conducted on the shallow reef flat off south Molokaʻi, Hawaiʻi. Corals were grown on wire platforms with attached coral recruitment tiles along a suspended solid concentration (SSC) gradient that ranged from 37 mg l−1 (inshore) to 3 mg l−1(offshore). Natural coral reef development on the reef flat is limited to areas with SSCs less than 10 mg l−1 as previously suggested in the scientific literature. However, the experimental corals held at much higher levels of turbidity showed surprisingly good survivorship and growth. High SSCs encountered on the reef flat reduced coral recruitment by one to three orders of magnitude compared to other sites throughout Hawaiʻi. There was a significant correlation between the biomass of macroalgae attached to the wire growth platforms at the end of the experiment and percentage of the corals showing mortality. We conclude that lack of suitable hard substrate, macroalgal competition, and blockage of recruitment on available substratum are major factors accounting for the low natural coral coverage in areas of high turbidity. The direct impact of high turbidity on growth and mortality is of lesser importance.

Spontaneous Spreading of a Droplet: The Role of Solid Continuity and Advancing Contact Angle.

Science.gov (United States)

Jiang, Youhua; Sun, Yujin; Drelich, Jaroslaw W; Choi, Chang-Hwan

2018-05-01

Spontaneous spreading of a droplet on a solid surface is poorly understood from a macroscopic level down to a molecular level. Here, we investigate the effect of surface topography and wettability on spontaneous spreading of a water droplet. Spreading force is measured for a suspended droplet that minimizes interference of kinetic energy in the spontaneous spreading during its contact with solid surfaces of discontinuous (pillar) and continuous (pore) patterns with various shapes and dimensions. Results show that a droplet cannot spread spontaneously on pillared surfaces regardless of their shapes or dimensions because of the solid discontinuity. On the contrary, a droplet on pored surfaces can undergo spontaneous spreading whose force increases with a decrease in the advancing contact angle. Theoretical models based on both the system free energy and capillary force along the contact line validate the direct and universal dependency of the spontaneous spreading force on the advancing contact angle.

Quantitative cross-sectional measurement of solid concentration distribution in slurries using a wire-mesh sensor

International Nuclear Information System (INIS)

Dos Santos, Eduardo Nunes; Da Silva, Marco Jose; Schleicher, Eckhard; Reinecke, Sebastian; Hampel, Uwe

2016-01-01

Wire-mesh sensors have so far been widely applied in gas–liquid flows where resistance or capacitance distributions are measured and converted into gas or liquid holdup distributions. In this work we report on the qualification of the wire-mesh imaging technique for the measurement of cross-sectional solid concentrations in solid–liquid mixtures. As the dielectric constants of solid particles are different from those of gas, water or oil in the flow, measuring this property can be used as an indication of solid distribution. Experiments were performed in a stirred tank of 100 mm diameter equipped with a capacitance wire-mesh sensor. The wire-mesh sensor was operated at an acquisition speed of 4000 frames per second and has a spatial resolution of 6.25 mm. As solids we used silica sand particles (diameter ∼250 μm) which were suspended in water in a volume concentration range of 1% to 35% to form slurries. By varying the stirring speed, different solid concentration distributions were produced and investigated. In order to convert the measured relative permittivity distribution into a solid concentration distribution, an empirical approach was employed. (paper)

Super-bridges suspended over carbon nanotube cables

Science.gov (United States)

Carpinteri, Alberto; Pugno, Nicola M.

2008-11-01

In this paper the new concept of 'super-bridges', i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of ~3. Too large compliance and dynamic self-excited resonances could be avoided by additional strands, rendering the super-bridge anchored as a spider's cobweb. As an example, we have computed the limit main spans of the current existing 19 suspended-deck bridges longer than 1 km assuming them to have substituted their cables with carbon nanotube bundles (thus maintaining the same geometry, with the exception of the length) finding spans of up to ~6.3 km. We thus suggest that the design of the Messina bridge in Italy, which would require a main span of ~3.3 km, could benefit from the use of carbon nanotube bundles. We believe that their use represents a feasible and economically convenient solution. The plausibility of these affirmations is confirmed by a statistical analysis of the existing 100 longest suspended bridges, which follow a Zipf's law with an exponent of 1.1615: we have found a Moore-like (i.e. exponential) law, in which the doubling of the capacity (here the main span) per year is substituted by the factor 1.0138. Such a law predicts that the realization of the Messina bridge using conventional materials will only occur around the middle of the present century, whereas it could be expected in the near future if carbon nanotube bundles were used. A simple cost analysis concludes the paper.

Super-bridges suspended over carbon nanotube cables

International Nuclear Information System (INIS)

Carpinteri, Alberto; Pugno, Nicola M

2008-01-01

In this paper the new concept of 'super-bridges', i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of ∼3. Too large compliance and dynamic self-excited resonances could be avoided by additional strands, rendering the super-bridge anchored as a spider's cobweb. As an example, we have computed the limit main spans of the current existing 19 suspended-deck bridges longer than 1 km assuming them to have substituted their cables with carbon nanotube bundles (thus maintaining the same geometry, with the exception of the length) finding spans of up to ∼6.3 km. We thus suggest that the design of the Messina bridge in Italy, which would require a main span of ∼3.3 km, could benefit from the use of carbon nanotube bundles. We believe that their use represents a feasible and economically convenient solution. The plausibility of these affirmations is confirmed by a statistical analysis of the existing 100 longest suspended bridges, which follow a Zipf's law with an exponent of 1.1615: we have found a Moore-like (i.e. exponential) law, in which the doubling of the capacity (here the main span) per year is substituted by the factor 1.0138. Such a law predicts that the realization of the Messina bridge using conventional materials will only occur around the middle of the present century, whereas it could be expected in the near future if carbon nanotube bundles were used. A simple cost analysis concludes the paper.

Simplified Entropic Model for the Evaluation of Suspended Load Concentration

Directory of Open Access Journals (Sweden)

Domenica Mirauda

2018-03-01

Full Text Available Suspended sediment concentration is a key aspect in the forecasting of river evolution dynamics, as well as in water quality assessment, evaluation of reservoir impacts, and management of water resources. The estimation of suspended load often relies on empirical models, of which efficiency is limited by their analytic structure or by the need for calibration parameters. The present work deals with a simplified fully-analytical formulation of the so-called entropic model in order to reproduce the vertical distribution of sediment concentration. The simplification consists in the leading order expansion of the generalized spatial coordinate of the entropic velocity profile that, strictly speaking, applies to the near-bed region, but that provides acceptable results also near the free surface. The proposed closed-form solution, which highlights the interplay among channel morphology, stream power, secondary flows, and suspended transport features, allows reducing the needed number of field measurements and, therefore, the time of field activities. Its accuracy and robustness were successfully tested based on the comparison with laboratory data reported in literature.

Effects of cadmium accumulation from suspended sediments and phytoplankton on the Oyster Saccostrea glomerata

Energy Technology Data Exchange (ETDEWEB)

Schmitz, Helena A.; Maher, William A., E-mail: bill.maher@canberra.edu.au; Taylor, Anne M.; Krikowa, Frank

2015-03-15

Highlights: • Saccostrea glomerata accumulated cadmium from sediments and phytoplankton. • Effects were similar for both pathways. • Antioxidant capacity, lipid peroxidation and lysosomal destabilisation were affected. • Clear exposure–dose–response relationships were demonstrated. - Abstract: Metals are accumulated by filter feeding organisms via water, ingestion of suspended sediments or food. The uptake pathway can affect metal toxicity. Saccostrea glomerata were exposed to cadmium through cadmium-spiked suspended sediments (19 and 93 μg/g dry mass) and cadmium-enriched phytoplankton (1.6–3 μg/g dry mass) and cadmium uptake and effects measured. Oysters accumulated appreciable amounts of cadmium from both low and high cadmium spiked suspended sediment treatments (5.9 ± 0.4 μg/g and 23 ± 2 μg/g respectively compared to controls 0.97 ± 0.05 μg/g dry mass). Only a small amount of cadmium was accumulated by ingestion of cadmium-enriched phytoplankton (1.9 ± 0.1 μg/g compared to controls 1.2 ± 0.1 μg/g). In the cadmium spiked suspended sediment experiments, most cadmium was desorbed from sediments and cadmium concentrations in S. glomerata were significantly related to dissolved cadmium concentrations (4–21 μg/L) in the overlying water. In the phytoplankton feeding experiment cadmium concentrations in overlying water were <0.01 μg/L. In both exposure experiments, cadmium-exposed oysters showed a significant reduction in total antioxidant capacity and significantly increased lipid peroxidation and percentage of destabilised lysosomes. Destabilised lysosomes in the suspended sediments experiments also resulted from stress of exposure to the suspended sediments. The study demonstrated that exposure to cadmium via suspended sediments and to low concentrations of cadmium through the ingestion of phytoplankton, can cause sublethal stress to S. glomerata.

Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

Science.gov (United States)

Voichick, Nicholas; Topping, David J.; Griffiths, Ronald E.

2018-03-01

Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water reservoirs, and (5) to establish connections with aquatic biological properties, such as primary production and predator-prey interactions. Turbidity is typically measured with an optical probe that detects light scattered from particles in the water. Probes have defined upper limits of the range of turbidity that they can measure. The general assumption is that when turbidity exceeds this upper limit, the values of turbidity will be constant, i.e., the probe is pegged; however, this assumption is not necessarily valid. In rivers with limited variation in the physical properties of the suspended sediment, at lower suspended-sediment concentrations, an increase in suspended-sediment concentration will cause a linear increase in turbidity. When the suspended-sediment concentration in these rivers is high, turbidity levels can exceed the upper measurement limit of an optical probe and record a constant pegged value. However, at extremely high suspended-sediment concentrations, optical turbidity probes do not necessarily stay pegged at a constant value. Data from the Colorado River in Grand Canyon, Arizona, USA, and a laboratory experiment both demonstrate that when turbidity exceeds instrument-pegged conditions, increasing suspended-sediment concentration (and thus increasing turbidity) may cause optical probes to record decreasing false turbidity values that appear to be within the valid measurement range of the probe. Therefore, under high-turbidity conditions, other surrogate measurements of turbidity (e.g., acoustic-attenuation measurements or suspended-sediment samples) are necessary to

SUSPENDED AND DISSOLVED MATTER FLUXES IN THE UPPER SELENGA RIVER BASIN

Directory of Open Access Journals (Sweden)

Sergey Chalov

2012-01-01

Full Text Available We synthesized recent field-based estimates of the dissolved ions (K+ Na+ Ca2+ Mg2+ Cl- SO42- HCO3-, biogens (NO3-, NO2-, PO43-(C, mg/l, heavy metal (Fesum, Mn, Pb and dissolved load (DL, kg/day, as far as suspended sediment concentration (SSC, mg/l and suspended load (SL, kg/day along upper Selenga river and its tributaries based on literature review and preliminary results of our 2011 field campaign. The crucial task of this paper is to provide full review of Russian, Mongolian and English-language literature which concern the matter fluxes in the upper part of Selenga river (within Mongolia. The exist estimates are compared with locations of 3 main matter sources within basin: mining and industry, river-bank erosion and slope wash. The heaviest increase of suspended and dissolved matter transport is indicated along Tuul-Orkhon river system (right tributary of the Selenga River where Mongolia capital Ulanbaatar, gold mine Zaamar and few other mines are located. In measurement campaigns conducted in 2005, 2006 and 2008 the increase directly after the Zaamar mining site was between 167 to 383 kg/day for Fe, between 15 and 5260 kg/day for Mn. Our field campaign indicated increase of suspended load along Tuul river from 4280 kg/day at the upstream point to 712000 kg/day below Ulaanbaatar and Zaamar. The results provide evidence on a potential connection between increased dissolved and suspended matter fluxes in transboundary rivers and zones of matter supply at industrial and mining centers, along eroded river banks and pastured lands. The gaps in the understanding of matter load fluxes within this basin are discussed with regards to determining further goals of hydrological and geochemical surveys.

Oil sands tailings treatment via surface modification of solids with polymers

Energy Technology Data Exchange (ETDEWEB)

Soane, D.; Ware, W.; Mahoney, R.; Kincaid, K. [Soane Energy, Cambridge, MA (United States)

2010-07-01

Oil sands fine tailings require large containment area and long-term storage. A recent directive has been established to reduce fluid tailings storage by 30 percent by 2012. This PowerPoint presentation described a method of treating oil sands tailings by modifying the surfaces of solids with polymers. The ATA process divided whole tailings into fines and coarse streams. The coarse stream was used to prepare anchor particles with a monolayer of tether polymers. An activator was added to the fine tailings in order to aggregate. The process cause a Velcro-like attraction between the activated fines and the tether-coated anchor particles. The solid ATA matrix trapped the fines and allowed water to drain more easily. Photographs of the process were provided. An analysis of the process demonstrated that 70 percent of the water in the tailings was recovered in less than 5 minutes. The water was clear, with less than 0.2 percent of suspended solids. The process is applicable to live tailings and mature fine tailings (MFT). tabs., figs.

Remote Sensing of Suspended Sediment Dynamics in the Mississippi Sound

Science.gov (United States)

Merritt, D. N.; Skarke, A. D.; Silwal, S.; Dash, P.

2016-02-01

The Mississippi Sound is a semi-enclosed estuary between the coast of Mississippi and a chain of offshore barrier islands with relatively shallow water depths and high marine biodiversity that is wildly utilized for commercial fishing and public recreation. The discharge of sediment-laden rivers into the Mississippi Sound and the adjacent Northern Gulf of Mexico creates turbid plumes that can extend hundreds of square kilometers along the coast and persist for multiple days. The concentration of suspended sediment in these coastal waters is an important parameter in the calculation of regional sediment budgets as well as analysis of water-quality factors such as primary productivity, nutrient dynamics, and the transport of pollutants as well as pathogens. The spectral resolution, sampling frequency, and regional scale spatial domain associated with satellite based sensors makes remote sensing an ideal tool to monitor suspended sediment dynamics in the Northern Gulf of Mexico. Accordingly, the presented research evaluates the validity of published models that relate remote sensing reflectance with suspended sediment concentrations (SSC), for similar environmental settings, with 51 in situ observations of SSC from the Mississippi Sound. Additionally, regression analysis is used to correlate additional in situ observations of SSC in Mississippi Sound with coincident observations of visible and near-infrared band reflectance collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard the Aqua satellite, in order to develop a site-specific empirical predictive model for SSC. Finally, specific parameters of the sampled suspended sediment such as grain size and mineralogy are analyzed in order to quantify their respective contributions to total remotely sensed reflectance.

High energy electron beam inactivation of lactate dehydrogenase suspended in different aqueous media

International Nuclear Information System (INIS)

Hategan, A.; Popescu, A.; Butan, C.; Oproiu, C.; Hategan, D.; Morariu, V.V.

1999-01-01

The direct and indirect effects of 5 MeV electron beam irradiation in the range (0-400 Gy) at 20 degC, 0 degC, -3 degC and -196 degC, as well as the influence of the aqueous suspending medium (ultrapure water and heavy water) on the total enzymatic activity of lactate dehydrogenase (LDH) have been studied. Our results showed an exponential decrease on the enzymatic activity of irradiated LDH, at all irradiation temperatures, independently of the direct or indirect action of radiation. The temperature gradient used to lower the temperature of the samples to -196 degC drastically influences the results. Freeze-thawing in two steps down to -196 degC protects LDH to radiation, in the dose range used. The data obtained here inform on the high energy electrons effects on the enzymatic activity loss during irradiation and during thawing, when the subsequent growth of the water crystals influences the three dimensional structure of the enzyme. A 99.98% concentration of D 2 O in the suspending medium of the enzyme decreases the global enzymatic activity, but reduces the rate of radiation inactivation of the enzyme. The rate of radiation inactivation of the enzyme suspended in ultrapure water is reduced when compared to the enzyme suspended in bidistilled water, but compared to the D 2 O suspended enzyme is lightly increased. (author)

78 FR 39710 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Opportunity To...

Science.gov (United States)

2013-07-02

... exporters.\\2\\ If the interested party intends for the Secretary to review sales of merchandise by an..., Finding, or Suspended Investigation; Opportunity To Request Administrative Review AGENCY: Import... review of that antidumping or countervailing duty order, finding, or suspended investigation. All...

78 FR 54235 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Opportunity To...

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2013-09-03

... exporters.\\2\\ If the interested party intends for the Secretary to review sales of merchandise by an..., Finding, or Suspended Investigation; Opportunity To Request Administrative Review AGENCY: Import... review of that antidumping or countervailing duty order, finding, or suspended investigation. All...

78 FR 33061 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Opportunity To...

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2013-06-03

... exporters.\\2\\ If the interested party intends for the Secretary to review sales of merchandise by an..., Finding, or Suspended Investigation; Opportunity To Request Administrative Review AGENCY: Import... review of that antidumping or countervailing duty order, finding, or suspended investigation. All...

76 FR 16770 - Petition To Suspend and Cancel All Registrations for the Soil Fumigant Iodomethane (Methyl Iodide...

Science.gov (United States)

2011-03-25

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2010-0541; FRL-8841-7] Petition To Suspend and Cancel... Earthjustice requesting that all uses of iodomethane (methyl iodide) be suspended and cancelled. The Agency is... uses of iodomethane (methyl iodide) be suspended and cancelled. The Agency is posting this petition for...

Quantifying suspended sediment loads delivered to Cheney Reservoir, Kansas: Temporal patterns and management implications

Science.gov (United States)

Stone, Mandy L.; Juracek, Kyle E.; Graham, Jennifer L.; Foster, Guy

2015-01-01

Cheney Reservoir, constructed during 1962 to 1965, is the primary water supply for the city of Wichita, the largest city in Kansas. Sediment is an important concern for the reservoir as it degrades water quality and progressively decreases water storage capacity. Long-term data collection provided a unique opportunity to estimate the annual suspended sediment loads for the entire history of the reservoir. To quantify and characterize sediment loading to Cheney Reservoir, discrete suspended sediment samples and continuously measured streamflow data were collected from the North Fork Ninnescah River, the primary inflow to Cheney Reservoir, over a 48-year period. Continuous turbidity data also were collected over a 15-year period. These data were used together to develop simple linear regression models to compute continuous suspended sediment concentrations and loads from 1966 to 2013. The inclusion of turbidity as an additional explanatory variable with streamflow improved regression model diagnostics and increased the amount of variability in suspended sediment concentration explained by 14%. Using suspended sediment concentration from the streamflow-only model, the average annual suspended sediment load was 102,517 t (113,006 tn) and ranged from 4,826 t (5,320 tn) in 1966 to 967,569 t (1,066,562 tn) in 1979. The sediment load in 1979 accounted for about 20% of the total load over the 48-year history of the reservoir and 92% of the 1979 sediment load occurred in one 24-hour period during a 1% annual exceedance probability flow event (104-year flood). Nearly 60% of the reservoir sediment load during the 48-year study period occurred in 5 years with extreme flow events (9% to 1% annual exceedance probability, or 11- to 104-year flood events). A substantial portion (41%) of sediment was transported to the reservoir during five storm events spanning only eight 24-hour periods during 1966 to 2013. Annual suspended sediment load estimates based on streamflow were, on

Effects of variation of flow and accumulation of suspended solids on the performance of anaerobic/aerobic biofilm system applied to grey water treatment. kenkiter dot koki roshoho no shori seino ni oyobosu ryuryo hendo oyobi kendaku busshitsu no eikyo

Energy Technology Data Exchange (ETDEWEB)

Okubo, T; Sagehashi, M; Otsuka, N; Okada, M; Murakami, A [Tokyo University of Agriculture and Technology, Tokyo (Japan)

1991-04-10

In this study, effects of variation of flow and accumulation of suspended solids (SS) on the performance of anaerobic/aerobic biofilm system were investigated through the laboratory test using synthetic wastewater and the field test using grey water. Effects of flow variation scarcely appeared on the time change of effluent quality in both cases where daily average hydraulic retention time (HRT) in anaerobic filter was 20h and that of aerobic filter was 6.7h. In the field test, however, removal rate of organic substances was lower (20-30%) than that of the laboratory test (90%), since SS content in grey water accumulated in the anaerobic filter which led dissolution of organic substances from accumulated SS, blocking, and short-circuit flow. Moreover, it was confirmed by the batch test that constituent of grey water has lower resolution for microorganisms and is more difficult to nitrate than synthetic waste water. 24 refs., 11 figs., 4 tabs.

Pulse Jet Mixing Tests With Noncohesive Solids

Energy Technology Data Exchange (ETDEWEB)

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro; Bailey, Sharon A.; Bower, John C.; Denslow, Kayte M.; Eakin, David E.; Elmore, Monte R.; Gauglitz, Phillip A.; Guzman, Anthony D.; Hatchell, Brian K.; Hopkins, Derek F.; Hurley, David E.; Johnson, Michael D.; Kirihara, Leslie J.; Lawler, Bruce D.; Loveland, Jesse S.; Mullen, O Dennis; Pekour, Mikhail S.; Peters, Timothy J.; Robinson, Peter J.; Russcher, Michael S.; Sande, Susan; Santoso, Christian; Shoemaker, Steven V.; Silva, Steve M.; Smith, Devin E.; Su, Yin-Fong; Toth, James J.; Wiberg, John D.; Yu, Xiao-Ying; Zuljevic, Nino

2009-05-11

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants. The test data were used to independently develop mixing models that can be used to predict full-scale WTP vessel performance and to rate current WTP mixing system designs against two specific performance requirements. One requirement is to ensure that all solids have been disturbed during the mixing action, which is important to release gas from the solids. The second requirement is to maintain a suspended solids concentration below 20 weight percent at the pump inlet. The models predict the height to which solids will be lifted by the PJM action, and the minimum velocity needed to ensure all solids have been lifted from the floor. From the cloud height estimate we can calculate the concentration of solids at the pump inlet. The velocity needed to lift the solids is slightly more demanding than "disturbing" the solids, and is used as a surrogate for this metric. We applied the models to assess WTP mixing vessel performance with respect to the two perform¬ance requirements. Each mixing vessel was evaluated against these two criteria for two defined waste conditions. One of the wastes was defined by design limits and one was derived from Hanford waste characterization reports. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy

The Shape of Breasts Suspended in Liquid

NARCIS (Netherlands)

De Kleijn, S.C.; Rensen, W.H.J.

2007-01-01

Philips has designed an optical mammography machine. In this machine the breast is suspended into a cup in which the measurements take place. A special fluid is inserted into the cup to prevent the light from going around the breast instead of going through it but this fluid also weakens the signal.

78 FR 25423 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Opportunity To...

Science.gov (United States)

2013-05-01

... for the Secretary to review sales of merchandise by an exporter (or a producer if that producer also..., Finding, or Suspended Investigation; Opportunity To Request Administrative Review AGENCY: Import... review of that antidumping or countervailing duty order, finding, or suspended investigation. All...

78 FR 13858 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Opportunity To...

Science.gov (United States)

2013-03-01

... for the Secretary to review sales of merchandise by an exporter (or a producer if that producer also..., Finding, or Suspended Investigation; Opportunity To Request Administrative Review AGENCY: Import... review of that antidumping or countervailing duty order, finding, or suspended investigation. All...

77 FR 59894 - Antidumping or Countervailing Duty Order, Finding, or Suspended Investigation; Opportunity To...

Science.gov (United States)

2012-10-01

... for the Secretary to review sales of merchandise by an exporter (or a producer if that producer also..., Finding, or Suspended Investigation; Opportunity To Request Administrative Review AGENCY: Import... review of that antidumping or countervailing duty order, finding, or suspended investigation. All...

High temporal resolution in situ measurement of the effective particle size characteristics of fluvial suspended sediment.

Science.gov (United States)

Williams, N D; Walling, D E; Leeks, G J L

2007-03-01

This paper reports the use of a LISST-100 device to monitor the effective particle size characteristics of suspended sediment in situ, and at a quasi-continuous temporal resolution. The study site was located on the River Exe at Thorverton, Devon, UK. This device has not previously been utilized in studies of fluvial suspended sediment at the storm event scale, and existing studies of suspended sediment dynamics have not involved such a high temporal resolution for extended periods. An evaluation of the field performance of the instrument is presented, with respect to innovative data collection and analysis techniques. It was found that trends in the effective particle size distribution (EPSD) and degree of flocculation of suspended sediment at the study site were highly complex, and showed significant short-term variability that has not previously been documented in the fluvial environment. The collection of detailed records of EPSD facilitated interpretation of the dynamic evolution of the size characteristics of suspended sediment, in relation to its likely source and delivery and flocculation mechanisms. The influence of measurement frequency is considered in terms of its implications for future studies of the particle size of fluvial suspended sediment employing in situ data acquisition.

Suspended sediment propagation in a long river reach: spatial and temporal dynamics of the Suspended Sediment Concentration-Water Discharge diagram for several hydrological events in the Northern French Alps.

Science.gov (United States)

Antoine, Germain; Jodeau, Magali; Camenen, Benoit; Esteves, Michel

2014-05-01

The relative propagation of water and suspended sediment is a key parameter to understand the suspended sediment transfers at the catchment scale. Several studies have shown the interest of performing detailed investigations of both temporal suspended sediment concentration (SSC) and water discharge signals. Most of them used temporal data from one measurement site, and classified hydrological events by studying the SSC curve as a function of water discharge (SSC-WD diagrams). Theoretical interpretations of these curves have been used to estimate the different sources of suspended sediment supply from sub-catchments, to evaluate the effect of seasons on the dynamics of suspended sediment, or to highlight the effect of a critical change at the catchment scale. However, few studies have focused on the signal propagation along the river channel. In this study, we analyze sampled data from a very well instrumented river reach in the Northern French Alps: the Arc-Isère River system. This gravel-bed river system is characterized by large concentrations of fines sediments, coming from the highly erodible mountains around. To control the hydraulic, sedimentary and chemical parameters from the catchment head, several gauging stations have been established since 2006. The continuous data measured at 4 gauging stations along 120 km of river have been analyzed to estimate the spatial and temporal dynamics of both SSC and water discharge. More precisely, about 40 major hydrological events have been sampled statistically between 2006 and 2012 from the data set and are analyzed in details. The study shows that the mean value of the propagation velocity is equal to 2 m/s and 3 m/s respectively for the SSC signal and the water discharge. These different propagation velocities imply that the suspended sediment mass is not only transported by the advection of the water at the river scale. The dispersion, erosion or deposition processes, and also the suspended sediment and discharge

Concentration of elements in suspended matter discharges to Lerma River, Mexico

International Nuclear Information System (INIS)

Avila-Perez, P.; Tejeda, S.; Carapia, L.; Barcelo-Quintal, I.; Martinez, T.

2011-01-01

The S, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Zn and Pb concentration and the elemental composition of particles in suspended matter from principal discharges to Lerma River, have been evaluated. The elemental concentration in suspended matter has been obtained by Energy Dispersive X-Ray Fluorescence Spectrometry. The elemental composition of particles has been obtained by means of Energy Dispersive X-Ray Spectrometry (EDS). The results show that K, Ca, Ti, Mn and Fe are mainly from natural origin in the Upper Course of the Lerma River (UCLR), where the principal contributions probably come from dragging of soils and sediments in the rainy season and Cr, Cu, Zn and Pb are mainly from anthropogenic origin where the principal contributions come from urban and industrial untreated discharge. The application of Energy Dispersive X-Ray Spectrometry plus Scanning Electron Microscopy is useful in the characterization of suspended matter in natural, anthropogenic and mixed water discharges. (author)

Air pollution in Aleppo city, gases,suspended particulates

International Nuclear Information System (INIS)

Othman, I.; Sabra, Sh.; Al-Kharfan, K.

1994-06-01

Total suspended particulates measured by using High Volume Air Sampler. The Co and O 3 were measured during weekday and weekend. The concentration of all pollutants at city center are higher than other measured areas. (author). 10 figs., 10 tabs

Effect of pH on Separation of Solid Content from Paint Contained Wastewater by a Coagulant-flocculant Compound

Directory of Open Access Journals (Sweden)

Mojtaba Semnani Rahbar

2014-05-01

Full Text Available Chemical wastewater treatment is one of the attracting and common methods for wastewater treatment among the currently employed chemical unit processes. The use of coagulant-flocculant compound is one of the efficient methods for separating of paint and recovery of water. In this research, it was introduced and the effect of pH on removal of solid content from solution was studied experimentally. For this purpose, sludge and suspended solid content of the solution were determined in a jar test by measurement of UV absorption of treated solution and solid separation percentage. The results showed that in pH range 9.5-10.5, maximum efficiency of solid content removal was up to 95%. Consequently, maximum paint removal was obtained in this range of pH. The separation of solid content of the solution was due to formation of aluminum hydroxide. As shown by the results, the reduction of potassium hydroxide as pH adjuster caused decrease of pH and consequently decreases of aluminum hydroxide and solid content removal.  

The observation of the Aharonov-Bohm effect in suspended semiconductor ring interferometers

Science.gov (United States)

Pokhabov, D. A.; Pogosov, A. G.; Shevyrin, A. A.; Zhdanov, E. Yu; Bakarov, A. K.; Shklyaev, A. A.; Ishutkin, S. V.; Stepanenko, M. V.; Shesterikov, E. V.

2018-02-01

A suspended semiconductor quantum ring interferometer based on a GaAs/AlGaAs heterostructure with a two-dimensional electron gas (2DEG) is created and experimentally studied. The electron interference in suspended 2DEG is observed. The interference manifests itself as the Aharonov-Bohm oscillations of the interferometer magnetoresistance, clearly observed before as well as after suspension. The amplitude of the oscillations remains almost unchanged after suspension.

Trends in suspended-sediment loads and concentrations in the Mississippi River Basin, 1950–2009

Science.gov (United States)

Heimann, David C.; Sprague, Lori A.; Blevins, Dale W.

2011-01-01

Trends in loads and concentrations of suspended sediment and suspended sand generally were downward for stations within the Mississippi River Basin during the 60-, 34-, and 12-year periods analyzed. Sediment transport in the lower Mississippi River has historically been, and continues to be, most closely correlative to sediment contributions from the Missouri River, which generally carried the largest annual suspended-sediment load of the major Mississippi River subbasins. The closure of Fort Randall Dam in the upper Missouri River in 1952 was the single largest event in the recorded historical decline of suspended-sediment loads in the Mississippi River Basin. Impoundments on tributaries and sediment reductions as a result of implementation of agricultural conservation practices throughout the basin likely account for much of the remaining Mississippi River sediment transport decline. Scour of the main-stem channel downstream from the upper Missouri River impoundments is likely the largest source of suspended sand in the lower Missouri River. The Ohio River was second to the Missouri River in terms of sediment contributions, followed by the upper Mississippi and Arkansas Rivers. Declines in sediment loads and concentrations continued through the most recent analysis period (1998–2009) at available Mississippi River Basin stations. Analyses of flow-adjusted concentrations of suspended sediment indicate the recent downward temporal changes generally can be explained by corresponding decreases in streamflows.

Element Geochemical Analysis of the Contribution of Aeolian Sand to Suspended Sediment in Desert Stream Flash Floods

Directory of Open Access Journals (Sweden)

Xiaopeng Jia

2014-01-01

Full Text Available The interaction of wind and water in semiarid and arid areas usually leads to low-frequency flash flood events in desert rivers, which have adverse effects on river systems and ecology. In arid zones, many aeolian dune-fields terminate in stream channels and deliver aeolian sand to the channels. Although aeolian processes are common to many desert rivers, whether the aeolian processes contribute to fluvial sediment loss is still unknown. Here, we identified the aeolian-fluvial cycling process responsible for the high rate of suspended sediment transport in the Sudalaer desert stream in the Ordos plateau of China. On the basis of element geochemistry data analysis, we found that aeolian sand was similar to suspended sediment in element composition, which suggests that aeolian sand contributes to suspended sediment in flash floods. Scatter plots of some elements further confirm that aeolian sand is the major source of the suspended sediment. Factor analysis and the relation between some elements and suspended sediment concentration prove that the greater the aeolian process, the higher the suspended sediment concentration and the greater the contribution of aeolian sand to suspended sediment yield. We conclude that aeolian sand is the greatest contributor to flash floods in the Sudalaer desert stream.

Element geochemical analysis of the contribution of aeolian sand to suspended sediment in desert stream flash floods.

Science.gov (United States)

Jia, Xiaopeng; Wang, Haibing

2014-01-01

The interaction of wind and water in semiarid and arid areas usually leads to low-frequency flash flood events in desert rivers, which have adverse effects on river systems and ecology. In arid zones, many aeolian dune-fields terminate in stream channels and deliver aeolian sand to the channels. Although aeolian processes are common to many desert rivers, whether the aeolian processes contribute to fluvial sediment loss is still unknown. Here, we identified the aeolian-fluvial cycling process responsible for the high rate of suspended sediment transport in the Sudalaer desert stream in the Ordos plateau of China. On the basis of element geochemistry data analysis, we found that aeolian sand was similar to suspended sediment in element composition, which suggests that aeolian sand contributes to suspended sediment in flash floods. Scatter plots of some elements further confirm that aeolian sand is the major source of the suspended sediment. Factor analysis and the relation between some elements and suspended sediment concentration prove that the greater the aeolian process, the higher the suspended sediment concentration and the greater the contribution of aeolian sand to suspended sediment yield. We conclude that aeolian sand is the greatest contributor to flash floods in the Sudalaer desert stream.

Suspended sediment behavior in a coastal dry-summer subtropical catchment: Effects of hydrologic preconditions

Science.gov (United States)

Variation in fluvial suspended sediment–discharge behavior is generally thought to be the product of changes in processes governing the delivery of sediment and water to the channel. The objective of this study was to infer sediment supply dynamics from the response of suspended ...

On the influence of suspended sediment transport on the generation of offshore sand waves

NARCIS (Netherlands)

Sterlini-Van der Meer, Fenneke; Hulscher, Suzanne J.M.H.; van den Berg, J.; Geurts, Bernardus J.; Clercx, H.J.H.; Uijttewaal, Wim

2007-01-01

Sand waves are bed-forms occurring in shallow seas. Although their characteristics are mainly affected by bed load transport, during rough weather suspended sediment transport can influence their characteristics. As a first step to model these influences, we added suspended sediment transport to a

Effect of phosphate ion on filtration characteristics of solids generated in simulated high level liquid waste

International Nuclear Information System (INIS)

Kondo, Y.

1998-01-01

The effect of phosphate ion on the filtration characteristics of solids generated in a high level liquid waste was experimentally examined. Addition of phosphate ion into the simulated HLLW induced the formation of phosphate such as zirconium phosphate and phosphomolybdic acid. The filtration rate of zirconium phosphate abruptly dropped in the midst of filtration because of a gel-cake formation on the filter surface. The denitration of the simulated HLLW contained zirconium phosphate improved the filterability of this gelatinous solid. The filtration rates of denitrated HLLW decreased with increase of the phosphate ion concentration, since the solids formed by denitration had irregular particle size and configuration in the simulated HLLW with phosphate ion. To increase the filtration rate of denitrated HLLW, a solid suspension filtration tester was designed. The solid-suspension accelerated the filtration rate only in the simulated HLLW with more than 1500 ppm phosphate ion concentration. Under this condition, the simple agitation can easily suspend the constituent solids of filter cake in the solution and a much higher filtration rate can be obtained because the filter cake is continuously swept from the filter surface by rotation of propellers. (authors)

Experimental study of perforated suspended ceilings as diffuse ventilation air inlets

DEFF Research Database (Denmark)

Hviid, Christian Anker; Svendsen, Svend

2013-01-01

An experimental study is reported in this paper for a diffuse ceiling ventilation concept. The analyses were carried out with two different porous surfaces mounted in a suspended ceiling: perforated tiles of aluminium and of gypsum. Ventilation air was supplied above the suspended ceiling effecti...... surface which increases the potential and applicability of the concept. Risk of thermal discomfort was not disclosed but the study did show evidence of large fluctuating air movements which could stem from transient behaviour creating sensations of draught to the occupants....

Initial Quantification of Suspended Sediment Loads for Three Alaska North Slope Rivers

Directory of Open Access Journals (Sweden)

Erica Lamb

2016-09-01

Full Text Available This study provides an initial assessment of suspended sediment transport in three rivers on the Alaska North Slope. From 2011 to 2013, the Anaktuvuk (69°27′51.00′′ N, 151°10′07.00′′ W, Chandler (69°17′0.30′′ N, 151°24′16.14′′ W, and Itkillik (68°51′59.46′′ N, 150°2′24.00′′ W Rivers were monitored for a variety of hydrologic, meteorologic, and sedimentologic characteristics. Watershed response to summer precipitation events was examined for each river. Bed sediment grain-size distribution was calculated using a photographic grid technique. Mean sediment diameters were 27.1 and 41.5 mm (Samples A and B for the Chandler, 35.8 mm for the Anaktuvuk, and 65.0 mm for the Itkillik. Suspended sediment rating curves were developed for each river. Suspended sediment discharge was analyzed. In 2011 and 2013, most of the total annual suspended sediment transport occurred during spring melt and widespread rainfall events, respectively. The results show that each river reacts differently to environmental inputs such as rain and basin characteristics.

Discrete Dynamics of Nanoparticle Channelling in Suspended Graphene

DEFF Research Database (Denmark)

Booth, Tim; Pizzocchero, Filippo; Andersen, Henrik

2011-01-01

We have observed a previously undescribed stepwise oxidation of mono- and few layer suspended graphene by silver nanoparticles in situ at subnanometer scale in an environmental transmission electron microscope. Over the range of 600–850 K, we observe crystallographically oriented channelling...

Exercise Intensity Thresholds: Identifying the Boundaries of Sustainable Performance.

Science.gov (United States)

Keir, Daniel A; Fontana, Federico Y; Robertson, Taylor C; Murias, Juan M; Paterson, Donald H; Kowalchuk, John M; Pogliaghi, Silvia

2015-09-01

Critical power (CP), respiratory compensation point (RCP), maximal lactate steady state (MLSS), and deoxyhemoglobin breakpoint ([HHb]BP) are alternative functional indices that are thought to demarcate the highest exercise intensity that can be tolerated for long durations. We tested the hypothesis that CP, RCP, MLSS, and [HHb]BP occur at the same metabolic intensity by examining the pulmonary oxygen uptake (V˙)O2p and power output (PO) associated with each "threshold." Twelve healthy men (mean ± SD age, 27 ± 3 yr) performed the following tests on a cycle ergometer: i) four to five exhaustive tests for determination of CP, ii) two to three 30-min constant-power trials for MLSS determination, and iii) a ramp incremental exercise test from which the V˙O2p and PO at RCP and [HHb]BP were determined. During each trial, breath-by-breath V˙O2p and ventilatory variables were measured with a metabolic cart and flowmeter turbine; near-infrared spectroscopy-derived [HHb] was monitored using a frequency domain multidistance system, and arterialized capillary blood lactate was sampled at regular intervals. There were no differences (P > 0.05) among the V˙O2p values associated with CP, RCP, MLSS, and [HHb]BP (CP, 3.29 ± 0.48; RCP, 3.34 ± 0.45; MLSS, 3.27 ± 0.44; [HHb]BP, 3.41 ± 0.46 L·min(-1)); however, the PO associated with RCP (262 ± 48 W) and [HHb]BP (273 ± 41 W) were greater (P 0.05). Although the standard methods for determination of CP, RCP, MLSS, and [HHb]BP are different, these indices occur at the same V˙O2p, suggesting that i) they may manifest as a result of similar physiological phenomenon and ii) each provides a valid delineation between tolerable and intolerable constant-power exercise.

Optimal control of suspended sediment distribution model of Talaga lake

Science.gov (United States)

Ratianingsih, R.; Resnawati, Azim, Mardlijah, Widodo, B.

2017-08-01

Talaga Lake is one of several lakes in Central Sulawesi that potentially to be managed in multi purposes scheme because of its characteristic. The scheme is addressed not only due to the lake maintenance because of its sediment but also due to the Algae farming for its biodiesel fuel. This paper governs a suspended sediment distribution model of Talaga lake. The model is derived from the two dimensional hydrodynamic shallow water equations of the mass and momentum conservation law of sediment transport. An order reduction of the model gives six equations of hyperbolic systems of the depth, two dimension directional velocities and sediment concentration while the bed elevation as the second order of turbulent diffusion and dispersion are neglected. The system is discreted and linearized such that could be solved numerically by box-Keller method for some initial and boundary condition. The solutions shows that the downstream velocity is play a role in transversal direction of stream function flow. The downstream accumulated sediment indicate that the suspended sediment and its changing should be controlled by optimizing the downstream velocity and transversal suspended sediment changing due to the ideal algae growth need.

Enhanced heterotrophic denitrification: effect of dairy industry sludge acclimatization and operating conditions.

Science.gov (United States)

Akbari Shahabi, Zeinab; Naeimpoor, Fereshteh

2014-06-01

Heterotrophic denitrification of drinking water was enhanced by selection of an anoxic sludge taken from a dairy industry among the sludges taken from various industries, and the effect of carbon sources was examined. Acclimatization to high nitrate concentration was then carried out in a five-stage process. Considering removals of both nitrate and nitrite, the sludge taken from anoxic unit of Tehran Pegah dairy industry was shown to be the superior microbial culture, with ethanol as carbon source as compared to acetate. To enhance the rate of denitrification, acclimatization to nitrate (at 100, 200, 400, 800, and 1,600 mg N-NO3/L) was carried out in sequencing batch reactors over a 3-month period under anoxic condition, and comparisons were made between the performances of acclimated and non-acclimated sludges at each stage. It was found that acclimatization up to the fourth stage enhanced the specific denitrification rate to a high value of 29.6 mg N-NO3/h/g mixed liquor suspended solids (MLSS), with no significant nitrite accumulation. Additionally, the effect of initial pH (6, 6.5, 7, and 7.5) and carbon-to-nitrogen (C/N) ratio (1, 1.5, 2, and 3) on the performance of this final acclimated sludge was assessed, where initial pH of 7 and C/N ratio of 1.5 resulted in the best performances considering both nitrate and nitrite removal.

Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

Science.gov (United States)

Voichick, Nicholas; Topping, David; Griffiths, Ronald

2018-01-01

Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water reservoirs, and (5) to establish connections with aquatic biological properties, such as primary production and predator–prey interactions. Turbidity is typically measured with an optical probe that detects light scattered from particles in the water. Probes have defined upper limits of the range of turbidity that they can measure. The general assumption is that when turbidity exceeds this upper limit, the values of turbidity will be constant, i.e., the probe is pegged; however, this assumption is not necessarily valid. In rivers with limited variation in the physical properties of the suspended sediment, at lower suspended-sediment concentrations, an increase in suspended-sediment concentration will cause a linear increase in turbidity. When the suspended-sediment concentration in these rivers is high, turbidity levels can exceed the upper measurement limit of an optical probe and record a constant pegged value. However, at extremely high suspended-sediment concentrations, optical turbidity probes do not necessarily stay pegged at a constant value. Data from the Colorado River in Grand Canyon, Arizona, USA, and a laboratory experiment both demonstrate that when turbidity exceeds instrument-pegged conditions, increasing suspended-sediment concentration (and thus increasing turbidity) may cause optical probes to record decreasing false turbidity values that appear to be within the valid measurement range of the probe. Therefore, under high-turbidity conditions, other surrogate measurements of turbidity (e.g., acoustic-attenuation measurements or suspended-sediment samples

Tracking suspended particle transport via radium isotopes (226Ra and 228Ra) through the Apalachicola–Chattahoochee–Flint River system

International Nuclear Information System (INIS)

Peterson, Richard N.; Burnett, William C.; Opsahl, Stephen P.; Santos, Isaac R.; Misra, Sambuddha; Froelich, Philip N.

2013-01-01

Suspended particles in rivers can carry metals, nutrients, and pollutants downstream which can become bioactive in estuaries and coastal marine waters. In river systems with multiple sources of both suspended particles and contamination sources, it is important to assess the hydrologic conditions under which contaminated particles can be delivered to downstream ecosystems. The Apalachicola–Chattahoochee–Flint (ACF) River system in the southeastern United States represents an ideal system to study these hydrologic impacts on particle transport through a heavily-impacted river (the Chattahoochee River) and one much less impacted by anthropogenic activities (the Flint River). We demonstrate here the utility of natural radioisotopes as tracers of suspended particles through the ACF system, where particles contaminated with arsenic (As) and antimony (Sb) have been shown to be contributed from coal-fired power plants along the Chattahoochee River, and have elevated concentrations in the surficial sediments of the Apalachicola Bay Delta. Radium isotopes ( 228 Ra and 226 Ra) on suspended particles should vary throughout the different geologic provinces of this river system, allowing differentiation of the relative contributions of the Chattahoochee and Flint Rivers to the suspended load delivered to Lake Seminole, the Apalachicola River, and ultimately to Apalachicola Bay. We also use various geochemical proxies ( 40 K, organic carbon, and calcium) to assess the relative composition of suspended particles (lithogenic, organic, and carbonate fractions, respectively) under a range of hydrologic conditions. During low (base) flow conditions, the Flint River contributed 70% of the suspended particle load to both the Apalachicola River and the bay, whereas the Chattahoochee River became the dominant source during higher discharge, contributing 80% of the suspended load to the Apalachicola River and 62% of the particles entering the estuary. Neither of these hydrologic

The use of modeling and suspended sediment concentration measurements for quantifying net suspended sediment transport through a large tidally dominated inlet

Science.gov (United States)

Erikson, Li H.; Wright, Scott A.; Elias, Edwin; Hanes, Daniel M.; Schoellhamer, David H.; Largier, John; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

2013-01-01

Sediment exchange at large energetic inlets is often difficult to quantify due complex flows, massive amounts of water and sediment exchange, and environmental conditions limiting long-term data collection. In an effort to better quantify such exchange this study investigated the use of suspended sediment concentrations (SSC) measured at an offsite location as a surrogate for sediment exchange at the tidally dominated Golden Gate inlet in San Francisco, CA. A numerical model was calibrated and validated against water and suspended sediment flux measured during a spring–neap tide cycle across the Golden Gate. The model was then run for five months and net exchange was calculated on a tidal time-scale and compared to SSC measurements at the Alcatraz monitoring site located in Central San Francisco Bay ~ 5 km from the Golden Gate. Numerically modeled tide averaged flux across the Golden Gate compared well (r2 = 0.86, p-value

2 CFR 901.1010 - Suspending official (Department of Energy supplement to government-wide definition at 2 CFR 180...

Science.gov (United States)

2010-01-01

... DEBARMENT AND SUSPENSION Definitions § 901.1010 Suspending official (Department of Energy supplement to government-wide definition at 2 CFR 180.1010). The suspending official for the Department of Energy... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Suspending official (Department of Energy...

An at-grade stabilization structure impact on runoff and suspended sediment

Science.gov (United States)

Minks, Kyle R.; Lowery, Birl; Madison, Fred W.; Ruark, Matthew; Frame, Dennis R.; Stuntebeck, Todd D.; Komiskey, Matthew J.

2012-01-01

In recent years, agricultural runoff has received more attention as a major contributor to surface water pollution. This is especially true for the unglaciated area of Wisconsin, given this area's steep topography, which makes it highly susceptible to runoff and soil loss. We evaluated the ability of an at-grade stabilization structure (AGSS), designed as a conservation practice to reduce the amount of overland runoff and suspended sediment transported to the surface waters of an agricultural watershed. Eight years of storm and baseflow data collected by the US Geological Survey–Wisconsin Water Science Center on a farm in west central Wisconsin were analyzed for changes in precipitation, storm runoff volume, and suspended sediment concentration before and after installation of an AGSS. The agricultural research site was designed as a paired watershed study in which monitoring stations were installed on the perennial streams draining both control and treatment watersheds. Linear mixed effects model analyses were conducted to determine if any statistically significant changes occurred in the water quality parameters before and after the AGSS was installed. Results indicated no significant changes (p = 0.51) in average event precipitation and runoff volumes before and after installation of the AGSS in either the treatment (NW) or control (SW) watersheds. However, the AGSS did significantly reduce the average suspended sediment concentration in the event runoff water (p = 0.02) in the NW from 972 to 263 mg L–1. In addition, particle size analyses, using light diffraction techniques, were conducted on soil samples taken from within the AGSS and adjacent valley and ridge top to determine if suspended sediments were being retained within the structure. Statistical analysis revealed a significantly (p clay inside the AGSS (37%) than outside (30%). These results indicate that the AGSS was successful in reducing the amount of suspended sediment transported to nearby

Levitation of Liquid Microdroplets Above A Solid Surface Subcooled to the Leidenfrost Temperature

Directory of Open Access Journals (Sweden)

Kirichenko D. P.

2016-01-01

Full Text Available Evaporation of liquid microdroplets that fall on a solid surface with the temperature of below the Leidenfrost temperature is studied. It has been found out that sufficiently small liquid droplets of about 10 microns can suspend at some distance from the surface (levitate and do not reach the surface; at that, the rate of droplet evaporation is reduced by an order as compared to microdroplets, which touch the surface. It is determined that in contrast to microdroplets, which touch the surface, the specific evaporation rate of levitating droplets is constant in time.

Suspended sediments from upstream tributaries as the source of downstream river sites

Science.gov (United States)

Haddadchi, Arman; Olley, Jon

2014-05-01

Understanding the efficiency with which sediment eroded from different sources is transported to the catchment outlet is a key knowledge gap that is critical to our ability to accurately target and prioritise management actions to reduce sediment delivery. Sediment fingerprinting has proven to be an efficient approach to determine the sources of sediment. This study examines the suspended sediment sources from Emu Creek catchment, south eastern Queensland, Australia. In addition to collect suspended sediments from different sites of the streams after the confluence of tributaries and outlet of the catchment, time integrated suspended samples from upper tributaries were used as the source of sediment, instead of using hillslope and channel bank samples. Totally, 35 time-integrated samplers were used to compute the contribution of suspended sediments from different upstream waterways to the downstream sediment sites. Three size fractions of materials including fine sand (63-210 μm), silt (10-63 μm) and fine silt and clay (<10 μm) were used to find the effect of particle size on the contribution of upper sediments as the sources of sediment after river confluences. And then samples were analysed by ICP-MS and -OES to find 41 sediment fingerprints. According to the results of Student's T-distribution mixing model, small creeks in the middle and lower part of the catchment were major source in different size fractions, especially in silt (10-63 μm) samples. Gowrie Creek as covers southern-upstream part of the catchment was a major contributor at the outlet of the catchment in finest size fraction (<10 μm) Large differences between the contributions of suspended sediments from upper tributaries in different size fractions necessitate the selection of appropriate size fraction on sediment tracing in the catchment and also major effect of particle size on the movement and deposition of sediments.

Multi-residue determination of the sorption of illicit drugs and pharmaceuticals to wastewater suspended particulate matter using pressurised liquid extraction, solid phase extraction and liquid chromatography coupled with tandem mass spectrometry.

Science.gov (United States)

Baker, David R; Kasprzyk-Hordern, Barbara

2011-11-04

Presented is the first comprehensive study of drugs of abuse on suspended particulate matter (SPM) in wastewater. Analysis of SPM is crucial to prevent the under-reporting of the levels of analyte that may be present in wastewater. Analytical methods to date analyse the aqueous part of wastewater samples only, removing SPM through the use of filtration or centrifugation. The development of an analytical method to determine 60 compounds on SPM using a combination of pressurised liquid extraction, solid phase extraction and liquid chromatography coupled with tandem mass spectrometry (PLE-SPE-LC-MS/MS) is reported. The range of compounds monitored included stimulants, opioid and morphine derivatives, benzodiazepines, antidepressants, dissociative anaesthetics, drug precursors, and their metabolites. The method was successfully validated (parameters studied: linearity and range, recovery, accuracy, reproducibility, repeatability, matrix effects, and limits of detection and quantification). The developed methodology was applied to SPM samples collected at three wastewater treatment plants in the UK. The average proportion of analyte on SPM as opposed to in the aqueous phase was 10% with regard to methadone, EDDP, EMDP, BZP, fentanyl, nortramadol, norpropoxyphene, sildenafil and all antidepressants (dosulepin, amitriptyline, nortriptyline, fluoxetine and norfluoxetine). Consequently, the lack of SPM analysis in wastewater sampling protocol could lead to the under-reporting of the measured concentration of some compounds. Copyright © 2011 Elsevier B.V. All rights reserved.

Writing and functionalisation of suspended DNA nanowires on superhydrophobic pillar arrays

KAUST Repository

Miele, Ermanno; Accardo, Angelo; Falqui, Andrea; Marini, Monica; Giugni, Andrea; Leoncini, Marco; De Angelis, Francesco De; Krahne, Roman; Di Fabrizio, Enzo M.

2014-01-01

Nanowire arrays and networks with precisely controlled patterns are very interesting for innovative device concepts in mesoscopic physics. In particular, DNA templates have proven to be versatile for the fabrication of complex structures that obtained functionality via combinations with other materials, for example by functionalisation with molecules or nanoparticles, or by coating with metals. Here, the controlled motion of the a three-phase contact line (TCL) of DNA-loaded drops on superhydrophobic substrates is used to fabricate suspended nanowire arrays. In particular, the deposition of DNA wires is imaged in situ, and different patterns are obtained on hexagonal pillar arrays by controlling the TCL velocity and direction. Robust conductive wires and networks are achieved by coating the wires with a thin layer of gold, and as proof of concept conductivity measurements are performed on single suspended wires. The plastic material of the superhydrophobic pillars ensures electrical isolation from the substrate. The more general versatility of these suspended nanowire networks as functional templates is outlined by fabricating hybrid organic-metal-semiconductor nanowires by growing ZnO nanocrystals onto the metal-coated nanowires.

Writing and functionalisation of suspended DNA nanowires on superhydrophobic pillar arrays

KAUST Repository

Miele, Ermanno

2014-08-08

Nanowire arrays and networks with precisely controlled patterns are very interesting for innovative device concepts in mesoscopic physics. In particular, DNA templates have proven to be versatile for the fabrication of complex structures that obtained functionality via combinations with other materials, for example by functionalisation with molecules or nanoparticles, or by coating with metals. Here, the controlled motion of the a three-phase contact line (TCL) of DNA-loaded drops on superhydrophobic substrates is used to fabricate suspended nanowire arrays. In particular, the deposition of DNA wires is imaged in situ, and different patterns are obtained on hexagonal pillar arrays by controlling the TCL velocity and direction. Robust conductive wires and networks are achieved by coating the wires with a thin layer of gold, and as proof of concept conductivity measurements are performed on single suspended wires. The plastic material of the superhydrophobic pillars ensures electrical isolation from the substrate. The more general versatility of these suspended nanowire networks as functional templates is outlined by fabricating hybrid organic-metal-semiconductor nanowires by growing ZnO nanocrystals onto the metal-coated nanowires.

Turbidity-controlled sampling for suspended sediment load estimation

Science.gov (United States)

Jack Lewis

2003-01-01

Abstract - Automated data collection is essential to effectively measure suspended sediment loads in storm events, particularly in small basins. Continuous turbidity measurements can be used, along with discharge, in an automated system that makes real-time sampling decisions to facilitate sediment load estimation. The Turbidity Threshold Sampling method distributes...

Suspended-sediment loads in the lower Stillaguamish River, Snohomish County, Washington, 2014–15

Science.gov (United States)

Anderson, Scott A.; Curran, Christopher A.; Grossman, Eric E.

2017-08-03

Continuous records of discharge and turbidity at a U.S. Geological Survey (USGS) streamgage in the lower Stillaguamish River were paired with discrete measurements of suspended-sediment concentration (SSC) in order to estimate suspended-sediment loads over the water years 2014 and 2015. First, relations between turbidity and SSC were developed and used to translate the continuous turbidity record into a continuous estimate of SSC. Those concentrations were then used to predict suspended-sediment loads based on the current discharge record, reported at daily intervals. Alternative methods were used to in-fill a small number of days with either missing periods of turbidity or discharge records. Uncertainties in our predictions at daily and annual time scales were estimated based on the parameter uncertainties in our turbidity-SSC regressions. Daily loads ranged from as high as 121,000 tons during a large autumn storm to as low as –56 tons, when tidal return flow moved more sediment upstream than river discharge did downstream. Annual suspended-sediment loads for both water years were close to 1.4 ± 0.2 million tons.

Turbidity and suspended sediment in the upper Esopus Creek watershed, Ulster County, New York

Science.gov (United States)

McHale, Michael R.; Siemion, Jason

2014-01-01

Suspended-sediment concentrations (SSCs) and turbidity were measured for 2 to 3 years at 14 monitoring sites throughout the upper Esopus Creek watershed in the Catskill Mountains of New York State. The upper Esopus Creek watershed is part of the New York City water-supply system that supplies water to more than 9 million people every day. Turbidity, caused primarily by high concentrations of inorganic suspended particles, is a potential water-quality concern because it colors the water and can reduce the effectiveness of drinking-water disinfection. The purposes of this study were to quantify concentrations of suspended sediment and turbidity levels, to estimate suspended-sediment loads within the upper Esopus Creek watershed, and to investigate the relations between SSC and turbidity. Samples were collected at four locations along the main channel of Esopus Creek and at all of the principal tributaries. Samples were collected monthly and during storms and were analyzed for SSC and turbidity in the laboratory. Turbidity was also measured every 15 minutes at six of the sampling stations with in situ turbidity probes.

Particles matter: Transformation of suspended particles in constructed wetlands

NARCIS (Netherlands)

Mulling, B.T.M.

2013-01-01

This thesis shows that constructed wetlands transform suspended particles in (treated) municipal wastewater through selective precipitation in ponds, biological filtering by plankton communities and physical and biological retention in reed beds. These processes effectively remove faecal indicator

Holding characteristics of planar objects suspended by near-field acoustic levitation

Science.gov (United States)

Matsuo; Koike; Nakamura; Ueha; Hashimoto

2000-03-01

The authors have found the acoustic levitation phenomenon where planar objects of 10 kg weight can be levitated near a vibration surface. This phenomenon has been studied for non-contact transportation. A circular planar object can be suspended without contacting a circular vibration plate. We have studied the holding force which acts horizontally on the levitated objects. The horizontal position of the object is stabilized by this force. In this paper, we discuss the effect of the radius of a levitated object, levitation distance, displacement amplitude of the vibration plate and the vibration mode on the suspending force.

The Influence of Turbulent Coherent Structure on Suspended Sediment Transport

Science.gov (United States)

Huang, S. H.; Tsai, C.

2017-12-01

The anomalous diffusion of turbulent sedimentation has received more and more attention in recent years. With the advent of new instruments and technologies, researchers have found that sediment behavior may deviate from Fickian assumptions when particles are heavier. In particle-laden flow, bursting phenomena affects instantaneous local concentrations, and seems to carry suspended particles for a longer distance. Instead of the pure diffusion process in an analogy to Brownian motion, Levy flight which allows particles to move in response to bursting phenomena is suspected to be more suitable for describing particle movement in turbulence. And the fractional differential equation is a potential candidate to improve the concentration profile. However, stochastic modeling (the Differential Chapmen-Kolmogorov Equation) also provides an alternative mathematical framework to describe system transits between different states through diffusion/the jump processes. Within this framework, the stochastic particle tracking model linked with advection diffusion equation is a powerful tool to simulate particle locations in the flow field. By including the jump process to this model, a more comprehensive description for suspended sediment transport can be provided with a better physical insight. This study also shows the adaptability and expandability of the stochastic particle tracking model for suspended sediment transport modeling.

Radium isotopes in suspended matter in an estuarine system in the southwest of Spain

International Nuclear Information System (INIS)

Perianez, R.; Garcia-Leon, M.; Abril, J.M.

1994-01-01

The presence of 226 Ra and 224 Ra in suspended matter from an estuarine system which surrounds a phosphate fertilizer complex has been investigated. The results have confirmed an important radioactive impact from the industrial complex, since up to 2.5 Bq 226 Ra/g suspended matter (dry) has been measured. The influence of tides and seasonal conditions, through changes in salinity, has been found to be relevant. The distribution coefficients for 226 Ra between the suspended matter and the river water have been calculated. The values are in agreement by order of magnitude with those found in the literature, but they clearly depend on tidal state and seasonal conditions. (author) 14 refs.; 6 figs.; 2 tabs

Room-Temperature Single-Photon Emission from Micrometer-Long Air-Suspended Carbon Nanotubes

Science.gov (United States)

Ishii, A.; Uda, T.; Kato, Y. K.

2017-11-01

Statistics of photons emitted by mobile excitons in individual carbon nanotubes are investigated. Photoluminescence spectroscopy is used to identify the chiralities and suspended lengths of air-suspended nanotubes, and photon-correlation measurements are performed at room temperature on telecommunication-wavelength nanotube emission with a Hanbury-Brown-Twiss setup. We obtain zero-delay second-order correlation g(2 )(0 ) less than 0.5, indicating single-photon generation. Excitation power dependence of the photon antibunching characteristics is examined for nanotubes with various chiralities and suspended lengths, where we find that the minimum value of g(2 )(0 ) is obtained at the lowest power. The influence of exciton diffusion and end quenching is studied by Monte Carlo simulations, and we derive an analytical expression for the minimum value of g(2 )(0 ). Our results indicate that mobile excitons in micrometer-long nanotubes can in principle produce high-purity single photons, leading to new design strategies for quantum photon sources.

Flow modelling to estimate suspended sediment travel times for two Canadian Deltas

Directory of Open Access Journals (Sweden)

S. R. Fassnacht

2000-01-01

Full Text Available The approximate travel times for suspended sediment transport through two multi-channel networks are estimated using flow modelling. The focus is on the movement of high sediment concentrations that travel rapidly downstream. Since suspended sediment transport through river confluences and bifurcation movement is poorly understood, it is assumed that the sediment moves at approximately the average channel velocity during periods of high sediment load movement. Calibration of the flow model is discussed, with an emphasis on the incorporation of cross-section data, that are not referenced to a datum, using a continuous water surface profile. Various flow regimes are examined for the Mackenzie and the Slave River Deltas in the Northwest Territories, Canada, and a significant variation in travel times is illustrated. One set of continuous daily sediment measurements throughout the Mackenzie Delta is used to demonstrate that the travel time estimates are reasonable. Keywords: suspended sediment; multi-channel river systems; flow modelling; sediment transport

Acoustic measuring techniques for suspended sediment

Science.gov (United States)

Gruber, P.; Felix, D.; Storti, G.; Lattuada, M.; Fleckenstein, P.; Deschwanden, F.

2016-11-01

Acoustic signals can be used in various ways for suspended sediment monitoring. One possibility which lends itself particularly well in the context of hydropower plants (HPPs), is to use installations for acoustic discharge measurement (ADM). Such installations already exist at waterways of many HPPs. Similar to certain turbidimeters, the attenuation of the forward scattered signal travelling through the water-sediment mixture is correlated with suspended sediment concentration (SSC). This correlation can be based on reference SSCs, e.g. from gravimetric analyses of bottle samples. Without the need of additional sensors and practically maintenance-free, this method is used successfully in the HPP Fieschertal to warn the HPP operator of high SSC to prevent excessive turbine abrasion. Acoustic methods and systems that allow for estimating both SSC and particle size distribution (PSD) are under development. The simultaneous determination of SSC and PSD is not possible using a single frequency. Therefore, multi-frequency approaches are investigated for generally scattered signals. When backscattered signals are used, a stronger frequency dependency can be exploited. However, the reliable simultaneous determination of particle size (and distribution) and concentration is still a major challenge due to a low signal-to-noise ratio and an ill- posed problem of estimating concentration and size from recorded signals. The optimal setup configuration (angles, frequencies) for such a system is not unique and further investigations are recommended.

Non-intrusive measurement and hydrodynamics characterization of gas-solid fluidized beds: a review

Science.gov (United States)

Sun, Jingyuan; Yan, Yong

2016-11-01

Gas-solid fluidization is a well-established technique to suspend or transport particles and has been applied in a variety of industrial processes. Nevertheless, our knowledge of fluidization hydrodynamics is still limited for the design, scale-up and operation optimization of fluidized bed reactors. It is, therefore, essential to characterize the two-phase flow behaviours in gas-solid fluidized beds and monitor the fluidization processes for control and optimization. A range of non-intrusive techniques have been developed or proposed for measuring the fluidization dynamic parameters and monitoring the flow status without disturbing or distorting the flow fields. This paper presents a comprehensive review of the non-intrusive measurement techniques and the current state of knowledge and experience in the characterization and monitoring of gas-solid fluidized beds. These techniques are classified into six main categories as per sensing principles, electrostatic, acoustic emission and vibration, visualization, particle tracking, laser Doppler anemometry and phase Doppler anemometry as well as pressure-fluctuation methods. Trends and future developments in this field are also discussed.

Non-intrusive measurement and hydrodynamics characterization of gas–solid fluidized beds: a review

International Nuclear Information System (INIS)

Sun, Jingyuan; Yan, Yong

2016-01-01

Gas–solid fluidization is a well-established technique to suspend or transport particles and has been applied in a variety of industrial processes. Nevertheless, our knowledge of fluidization hydrodynamics is still limited for the design, scale-up and operation optimization of fluidized bed reactors. It is, therefore, essential to characterize the two-phase flow behaviours in gas–solid fluidized beds and monitor the fluidization processes for control and optimization. A range of non-intrusive techniques have been developed or proposed for measuring the fluidization dynamic parameters and monitoring the flow status without disturbing or distorting the flow fields. This paper presents a comprehensive review of the non-intrusive measurement techniques and the current state of knowledge and experience in the characterization and monitoring of gas–solid fluidized beds. These techniques are classified into six main categories as per sensing principles, electrostatic, acoustic emission and vibration, visualization, particle tracking, laser Doppler anemometry and phase Doppler anemometry as well as pressure-fluctuation methods. Trends and future developments in this field are also discussed. (topical review)

Investigation of suspended sediment transport using ultrasonic techniques

DEFF Research Database (Denmark)

Bjørnø, Irina; Jensen, Leif Bjørnø

1994-01-01

The results of the initial experimental studies involving the scattering of ultrasonic signals from canonical and non-canonical shaped suspended particles with known elastical qualities are reported. These results have formed the basis for the development of a numerical model for ultrasound...... propagation through low-concentration suspensions of sand particles...

Muscular contribution to low-back loading and stiffness during standard and suspended push-ups.

Science.gov (United States)

Beach, Tyson A C; Howarth, Samuel J; Callaghan, Jack P

2008-06-01

Push-up exercises are normally performed to challenge muscles that span upper extremity joints. However, it is also recognized that push-ups provide an effective abdominal muscle challenge, especially when the hands are in contact with a labile support surface. The purpose of this study was to compare trunk muscle activation levels and resultant intervertebral joint (IVJ) loading when standard and suspended push-ups were performed, and to quantify and compare the contribution of trunk muscles to IVJ rotational stiffness in both exercises. Eleven recreationally trained male volunteers performed sets of standard and suspended push-ups. Upper body kinematic, kinetic, and EMG data were collected and input into a 3D biomechanical model of the lumbar torso to quantify lumbar IVJ loading and the contributions of trunk muscles to IVJ rotational stiffness. When performing suspended push-ups, muscles of the abdominal wall and the latissimus dorsi were activated to levels that were significantly greater than those elicited when performing standard push-ups (ppush-ups. Also directly resulting from the increased activation levels of the abdominal muscles and the latissimus dorsi during suspended push-ups was increased muscular contribution to lumbar IVJ rotational stiffness (ppush-ups appear to provide a superior abdominal muscle challenge. However, for individuals unable to tolerate high lumbar IVJ compressive loads, potential benefits gained by incorporating suspended push-ups into their resistance training regimen may be outweighed by the risk of overloading low-back tissues.

Temporal variability in the suspended sediment load and streamflow of the Doce River

Science.gov (United States)

Oliveira, Kyssyanne Samihra Santos; Quaresma, Valéria da Silva

2017-10-01

Long-term records of streamflow and suspended sediment load provide a better understanding of the evolution of a river mouth, and its adjacent waters and a support for mitigation programs associated with extreme events and engineering projects. The aim of this study is to investigate the temporal variability in the suspended sediment load and streamflow of the Doce River to the Atlantic Ocean, between 1990 and 2013. Streamflow and suspended sediment load were analyzed at the daily, seasonal, and interannual scales. The results showed that at the daily scale, Doce River flood events are due to high intensity and short duration rainfalls, which means that there is a flashy response to rainfall. At the monthly and season scales, approximately 94% of the suspended sediment supply occurs during the wet season. Extreme hydrological events are important for the interannual scale for Doce River sediment supply to the Atlantic Ocean. The results suggest that a summation of anthropogenic interferences (deforestation, urbanization and soil degradation) led to an increase of extreme hydrological events. The findings of this study shows the importance of understanding the typical behavior of the Doce River, allowing the detection of extreme hydrological conditions, its causes and possible environmental and social consequences.

DYNAMIC SUFFICIENCY OF THE MAGNETICALLY SUSPENDED TRAIN

Directory of Open Access Journals (Sweden)

V. A. Polyakov

2013-11-01

Full Text Available Purpose. The basic criterion of the magnetically suspended train's consumer estimation is a quality of its mechanical motion. This motion is realized in unpredictable conditions and, for purposefulness preservation, should adapt to them. Such adaptation is possible only within the limits of system’s dynamic sufficiency. Sufficiency is understood as presence at system of resources, which allow one to realize its demanded motions without violating actual restrictions. Therefore presence of such resources is a necessary condition of preservation of required purposefulness of train's dynamics, and verification of the mentioned sufficiency is the major component of this dynamic research. Methodology. Methods of the set theory are used in work. Desirable and actual approachability spaces of the train are found. The train is considered dynamically sufficient in zones of the specified spaces overlapping. Findings. Within the limits of the accepted treatment of train's dynamic sufficiency, verification of its presence, as well as a stock (or deficiency of preservations can be executed by the search and the subsequent estimation of such overlapping zones. Operatively (directly during motion it can be realized on the train's ODC with use, for example, of computer mathematics system Mathematica. It possesses extensive opportunities of highly efficient and, at the same time, demanding an expense concerning small resources information manipulation. The efficiency of using of created technique is illustrated on an example of vehicle's acceleration research. Calculation is executed with use of the constructed computer model of interaction of an independent traction electromagnetic subsystem of an artifact with its mechanical subsystem. Originality. The technique of verification of the high-speed magnetically suspended train's dynamic sufficiency is developed. The technique is highly efficient, it provides sufficient presentation and demands an expense of the

Large theoretical thermoelectric power factor of suspended single-layer MoS{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Babaei, Hasan, E-mail: babaei@illinois.edu, E-mail: babaei@auburn.edu [Mechanical Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-2906 (United States); Mechanical Engineering Department, Auburn University, Auburn, Alabama 36849-5341 (United States); Khodadadi, J. M. [Mechanical Engineering Department, Auburn University, Auburn, Alabama 36849-5341 (United States); Sinha, Sanjiv [Mechanical Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-2906 (United States)

2014-11-10

We have calculated the semi-classical thermoelectric power factor of suspended single-layer (SL)- MoS{sub 2} utilizing electron relaxation times derived from ab initio calculations. Measurements of the thermoelectric power factor of SL-MoS{sub 2} on substrates reveal poor power factors. In contrast, we find the thermoelectric power factor of suspended SL-MoS{sub 2} to peak at ∼2.8 × 10{sup 4} μW/m K{sup 2} at 300 K, at an electron concentration of 10{sup 12} cm{sup −2}. This figure is higher than that in bulk Bi{sub 2}Te{sub 3}, for example. Given its relatively high thermal conductivity, suspended SL-MoS{sub 2} may hold promise for in-plane thin-film Peltier coolers, provided reasonable mobilities can be realized.

Research on the Hydrophilic Modified of LDPE for the New Biological Suspended Filler

Directory of Open Access Journals (Sweden)

Kang Weijia

2016-01-01

Full Text Available Urban sewage is one of the main pollution sources of the city, which pollute soil, deteriorate the water quality and increase the water shortages and urban load. LDPE is low cost and widely used as the basic material of wastewater treatment, but LDPE’s hydrophilic is not good enough to meet the need of suspended filler in wastewater treatment. In this paper the hydrophilic modified of LDPE for the new biological suspended filler was studied and the preparation and processing technique based on LDPE was researched. The hydrophilic and mechanic performance of the hydrophilic modified materials was tested. Results shown that the new type of hydrophilic modified materials has good hydrophilic and meets the demand of urban sewage treatment. The research on the new suspended filler materials has great meaning in solving the problem of urban sewage and recycling.

Turbidity threshold sampling for suspended sediment load estimation

Science.gov (United States)

Jack Lewis; Rand Eads

2001-01-01

Abstract - The paper discusses an automated procedure for measuring turbidity and sampling suspended sediment. The basic equipment consists of a programmable data logger, an in situ turbidimeter, a pumping sampler, and a stage-measuring device. The data logger program employs turbidity to govern sample collection during each transport event. Mounting configurations and...

Year-round performance of a modified single-basin solar still with mica plate as a suspended absorber

Energy Technology Data Exchange (ETDEWEB)

El-Sebaii, A.A.; Aboul-Enein, S.; Ramadan, M.R.I.; El-Bialy, E. [Tanta University (Egypt). Faculty of Science

2000-01-01

In a previous study, a single-basin solar still with suspended absorber (SBSSBA) made from aluminium was constructed and investigated experimentally and theoretically. It was found that the daily productivity of the still was about 20% higher than that of the conventional single-basin solar still (SBSS). In this paper, the effect of thermal conductivity of the suspended absorber on the daily productivity of the still is investigated experimentally using aluminium, copper, stainless steel and mica plates as suspended absorbers. The results obtained are compared with those obtained for the SBSS tested under the same climatic conditions of Tanta (lat. 30{sup o} 47' N). The results indicate that it is advisable to use suspended plates made from insulating materials, such as mica, plastic, glass, etc. The daily productivity of the modified still with mica is found to be 42% higher than that of SBSS. Further, the effect of thickness of the suspended absorber on the productivity as well as the year-round performances of both SBSSBA and SBSS for the year 1996 are studied by computer simulation. There is good evidence that the productivity of SBSSBA is less dependent on the thickness of the suspended plate. The annual average productivities of the modified still with mica are found to be 23 and 15.8% higher than those of the conventional still when the basin water masses are 80 and 40 kg, respectively. This indicates that the suspended plate becomes more effective at higher masses of basin water. (author)

The role of suspension events in cross-shore and longshore suspended sediment transport in the surf zone

Science.gov (United States)

Jaffe, Bruce E.

2015-01-01

Suspension of sand in the surf zone is intermittent. Especially striking in a time series of concentration are periods of intense suspension, suspension events, when the water column suspended sediment concentration is an order of magnitude greater than the mean concentration. The prevalence, timing, and contribution of suspension events to cross-shore and longshore suspended sediment transport are explored using field data collected in the inner half of the surf zone during a large storm at Duck, NC. Suspension events are defined as periods when the concentration is above a threshold. Events tended to occur during onshore flow under the wave crest, resulting in an onshore contribution to the suspended sediment transport. Even though large events occurred less than 10 percent of the total time, at some locations onshore transport associated with suspension events was greater than mean-current driven offshore-directed transport during non-event periods, causing the net suspended sediment transport to be onshore. Events and fluctuations in longshore velocity were not correlated. However, events did increase the longshore suspended sediment transport by approximately the amount they increase the mean concentration, which can be up to 35%. Because of the lack of correlation, the longshore suspended sediment transport can be modeled without considering the details of the intensity and time of events as the vertical integration of the product of the time-averaged longshore velocity and an event-augmented time-averaged concentration. However, to accurately model cross-shore suspended sediment transport, the timing and intensity of suspension events must be reproduced.

Modeling long-term suspended-sediment export from an undisturbed forest catchment

Science.gov (United States)

Zimmermann, Alexander; Francke, Till; Elsenbeer, Helmut

2013-04-01

Most estimates of suspended sediment yields from humid, undisturbed, and geologically stable forest environments fall within a range of 5 - 30 t km-2 a-1. These low natural erosion rates in small headwater catchments (≤ 1 km2) support the common impression that a well-developed forest cover prevents surface erosion. Interestingly, those estimates originate exclusively from areas with prevailing vertical hydrological flow paths. Forest environments dominated by (near-) surface flow paths (overland flow, pipe flow, and return flow) and a fast response to rainfall, however, are not an exceptional phenomenon, yet only very few sediment yields have been estimated for these areas. Not surprisingly, even fewer long-term (≥ 10 years) records exist. In this contribution we present our latest research which aims at quantifying long-term suspended-sediment export from an undisturbed rainforest catchment prone to frequent overland flow. A key aspect of our approach is the application of machine-learning techniques (Random Forest, Quantile Regression Forest) which allows not only the handling of non-Gaussian data, non-linear relations between predictors and response, and correlations between predictors, but also the assessment of prediction uncertainty. For the current study we provided the machine-learning algorithms exclusively with information from a high-resolution rainfall time series to reconstruct discharge and suspended sediment dynamics for a 21-year period. The significance of our results is threefold. First, our estimates clearly show that forest cover does not necessarily prevent erosion if wet antecedent conditions and large rainfalls coincide. During these situations, overland flow is widespread and sediment fluxes increase in a non-linear fashion due to the mobilization of new sediment sources. Second, our estimates indicate that annual suspended sediment yields of the undisturbed forest catchment show large fluctuations. Depending on the frequency of large

Relationship between dioxin concentration and particle size for suspended sediment

Energy Technology Data Exchange (ETDEWEB)

Kitamura, K.; Sakurai, T.; Choi, J.W.; Suzuki, N.; Morita, M. [National Inst. for Environmental Studies, Tsukuba (Japan)

2004-09-15

The purpose of the present study was to find out how the amounts of adsorbed dioxins, i.e., polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/Fs), mono-ortho-polychlorinated biphenyls (PCBs) and non-ortho-PCBs, vary with the particle size of suspended sediment. As dioxins are hydrophobic, they tend to adsorb onto particles suspended in water, and the determination of which dioxin congeners readily dissolve in water or adsorb onto particles is central to the characterization of dioxin behavior in water/sediment systems. Presumably suspension of sediments and the size of the particles govern the transfer of dioxins to aquatic organisms. Therefore, in the present study, we investigated the relationship between the amount of dioxins and the particle-size distribution of resuspended, rather than settled, sediment.

Increasing precision of turbidity-based suspended sediment concentration and load estimates.

Science.gov (United States)

Jastram, John D; Zipper, Carl E; Zelazny, Lucian W; Hyer, Kenneth E

2010-01-01

Turbidity is an effective tool for estimating and monitoring suspended sediments in aquatic systems. Turbidity can be measured in situ remotely and at fine temporal scales as a surrogate for suspended sediment concentration (SSC), providing opportunity for a more complete record of SSC than is possible with physical sampling approaches. However, there is variability in turbidity-based SSC estimates and in sediment loadings calculated from those estimates. This study investigated the potential to improve turbidity-based SSC, and by extension the resulting sediment loading estimates, by incorporating hydrologic variables that can be monitored remotely and continuously (typically 15-min intervals) into the SSC estimation procedure. On the Roanoke River in southwestern Virginia, hydrologic stage, turbidity, and other water-quality parameters were monitored with in situ instrumentation; suspended sediments were sampled manually during elevated turbidity events; samples were analyzed for SSC and physical properties including particle-size distribution and organic C content; and rainfall was quantified by geologic source area. The study identified physical properties of the suspended-sediment samples that contribute to SSC estimation variance and hydrologic variables that explained variability of those physical properties. Results indicated that the inclusion of any of the measured physical properties in turbidity-based SSC estimation models reduces unexplained variance. Further, the use of hydrologic variables to represent these physical properties, along with turbidity, resulted in a model, relying solely on data collected remotely and continuously, that estimated SSC with less variance than a conventional turbidity-based univariate model, allowing a more precise estimate of sediment loading, Modeling results are consistent with known mechanisms governing sediment transport in hydrologic systems.

Sub-10-nm suspended nano-web formation by direct laser writing

Science.gov (United States)

Wang, Sihao; Yu, Ye; Liu, Hailong; Lim, Kevin T. P.; Madurai Srinivasan, Bharathi; Zhang, Yong Wei; Yang, Joel K. W.

2018-06-01

A diffraction-limited three-dimensional (3D) direct laser writing (DLW) system based on two-photon polymerization can routinely pattern structures at the 100 nm length scale. Several schemes have been developed to improve the patterning resolution of 3D DLW but often require customized resist formulations or multi-wavelength exposures. Here, we introduce a scheme to produce suspended nano-webs with feature sizes below 10 nm in IP-Dip resist using sub-threshold exposure conditions in a commercial DLW system. The narrowest suspended lines (nano-webs) measured 7 nm in width. Larger ∼20 nm nano-webs were patterned with ∼80% yield at increased laser powers. In addition, closely spaced nano-gaps with a center-to-center distance of 33 nm were produced by patterning vertically displaced suspended lines followed by metal deposition and liftoff. We provide hypotheses and present preliminary results for a mechanism involving the initiation of a percolative path and a strain-induced narrowing in the nano-web formation. Our approach allows selective features to be patterned with dimensions comparable to the sub-10 nm patterning capability of electron-beam lithography (EBL).

Protection against suspended sand: the function of the branchial membrane in the blue mussel Mytilus edulis

Science.gov (United States)

de Vooys, C. G. N.

2006-09-01

Blue mussels ( Mytilus edulis) living in estuaries have to cope with varying concentrations of suspended sand. Sand flowing through the inhalant siphons comes into the infrabranchial chamber. The inhalant siphon can be partially closed by the branchial membrane. As a result the inward flow decreases, and suspended sand sinks and can be eliminated. Experiments with mussels from three ecologically different locations showed about the same response of the branchial membrane on contact with suspended sand. The presence and function of the branchial membrane appears to be an adaptation of mussels to their estuarine environment.

Novel Resuscitation from Lethal Hemorrhage - Suspended Animation for Delayed Resuscitation

National Research Council Canada - National Science Library

Safar, Peter

2002-01-01

.... We have conceived and documented "suspended animation for delayed resuscitation" with the use of hypothermic saline flush into the aorta within the first 5 minute of no blood flow, using novel...

Evaluation of the suspending properties of Abizia zygia gum on ...

African Journals Online (AJOL)

Purpose: Some excipients are currently available for the formulation of pharmaceutical suspensions. ... Method: The suspending properties of Albizia zygia gum (family ... Characterization tests were carried out on purified Albizia zygia gum.

Caffeine Affects Time to Exhaustion and Substrate Oxidation during Cycling at Maximal Lactate Steady State

Directory of Open Access Journals (Sweden)

Rogério Santos de Oliveira Cruz

2015-06-01

Full Text Available This study analyzed the effects of caffeine intake on whole-body substrate metabolism and exercise tolerance during cycling by using a more individualized intensity for merging the subjects into homogeneous metabolic responses (the workload associated with the maximal lactate steady state—MLSS. MLSS was firstly determined in eight active males (25 ± 4 years, 176 ± 7 cm, 77 ± 11 kg using from two to four constant-load tests of 30 min. On two following occasions, participants performed a test until exhaustion at the MLSS workload 1 h after taking either 6 mg/kg of body mass of caffeine or placebo (dextrose, in a randomized, double-blinded manner. Respiratory exchange ratio was calculated from gas exchange measurements. There was an improvement of 22.7% in time to exhaustion at MLSS workload following caffeine ingestion (95% confidence limits of ±10.3%, p = 0.002, which was accompanied by decrease in respiratory exchange ratio (p = 0.001. These results reinforce findings indicating that sparing of the endogenous carbohydrate stores could be one of the several physiological effects of caffeine during submaximal performance around 1 h.

Discriminating silt-and-clay from suspended-sand in rivers using side-looking acoustic profilers

Science.gov (United States)

Wright, Scott A.; Topping, David J.; Williams, Cory A.

2010-01-01

The ability to accurately monitor suspended-sediment flux in rivers is needed to support many types of studies, because the sediment that typically travels in suspension affects geomorphology and aquatic habitat in a variety of ways (e.g. bank and floodplain deposition, bar morphology, light penetration and primary productivity, tidal wetland deposition in the context of sea-level rise, sediment-associated contaminants, reservoir sedimentation and potential erosion during dam removal, among others). In addition, human-induced changes to the landscape have resulted in substantially altered suspended-sediment loads (Syvitski et al., 2005). Thus, accurate monitoring of suspended-sediment flux is necessary for informed resource management of rivers. Because of this need, a variety of techniques have been developed and applied for suspendedsediment monitoring. The traditional approach in the United States, which was developed and has been used extensively by the U.S. Geological Survey (USGS), is to collect an isokinetic, velocity-weighted sample from a river cross-section, analyze the sample in the laboratory, and use water-discharge records to compute a record of suspended-sediment flux (Guy, 1969, Guy, 1970, Edwards and Glysson, 1999, Porterfield, 1972). The labor and expense associated with this traditional approach is substantial such that the number of USGS gages reporting daily records of suspended-sediment flux decreased from 364 in 1981 to 120 in 2003 (Osterkamp et al., 2004). Also, the traditional sampling approach is limited with respect to the temporal resolution that can be achieved, thus requiring the use of approximate relations between suspended-sediment concentration and water discharge to fill gaps between samples. To address these limitations, several indirect or "surrogate" measures have been investigated (see e.g. Gray and Gartner, 2009) most notably optical backscatter (i.e. turbidity), laser-diffraction, and acoustic backscatter. These indirect

Measuring the height-to-height correlation function of corrugation in suspended graphene

International Nuclear Information System (INIS)

Kirilenko, D.A.; Brunkov, P.N.

2016-01-01

Nanocorrugation of 2D crystals is an important phenomenon since it affects their electronic and mechanical properties. The corrugation may have various sources; one of them is flexural phonons that, in particular, are responsible for the thermal conductivity of graphene. A study of corrugation of just the suspended graphene can reveal much of valuable information on the physics of this complicated phenomenon. At the same time, the suspended crystal nanorelief can hardly be measured directly because of high flexibility of the 2D crystal. Moreover, the relief portion related to rapid out-of-plane oscillations (flexural phonons) is also inaccessible by such measurements. Here we present a technique for measuring the Fourier components of the height–height correlation function H(q) of suspended graphene which includes the effect of flexural phonons. The technique is based on the analysis of electron diffraction patterns. The H(q) is measured in the range of wavevectors q≈0.4–4.5 nm"−"1. At the upper limit of this range H(q) does follow the T/κq"4 law. So, we measured the value of suspended graphene bending rigidity κ=1.2±0.4 eV at ambient temperature T≈300 K. At intermediate wave vectors, H(q) follows a slightly weaker exponent than theoretically predicted q"−"3"."1"5 but is closer to the results of the molecular dynamics simulation. At low wave vectors, the dependence becomes even weaker, which may be a sign of influence of charge carriers on the dynamics of undulations longer than 10 nm. The technique presented can be used for studying physics of flexural phonons in other 2D materials. - Highlights: • A technique for measuring free-standing 2D crystal corrugation is proposed. • The height-to-height correlation function of the suspended graphene corrugation is measured. • Various parameters of the intrinsic graphene properties are experimentally determined.

Concentration Measurements of Suspended Load using ADV with Influence of the Particle Size

Science.gov (United States)

Schwarzwälder, Kordula

2017-04-01

ADV backscatter data can be used under certain conditions to gain information about the concentrations of suspended loads. This was shown in many studies before (Fugate and Friedrichs 2002; Chanson et al 2008; Ha et al. 2009). This paper reports on a pre-study to investigate the influence of particle size on concentration measurements for suspended sediment load with ADV. The study was conducted in a flume in the Oskar-von-Miller-Institute using fresh water from a river including the natural suspended load. The ADV used in the experiments was a Vectrino Profiler (Nortek). In addition water samples were taken for TSS and TOC. For the measurements a surge was generated in the flume to ensure that also particles of larger size will be present in the water phase. The measurements and samples were taken during the whole surge event. Therefore we were able to find a good correlation between the backscatter data of the ADV and the TSS as well as TOC results. For the decreasing part of the flow event the concentration of TOC in the suspended load of the water phase is decreasing much slower than the TSS and results in a damped decrease of the backscatter values. This means that the results for concentration measurements might be slightly influenced by the size of the particles. Further evaluations of measurements conducted with a LISST SL (Sequoia) will be investigated to show the trend of the particle sizes during this process and fortify this result. David C. Fugate, Carl T. Friedrichs, Determining concentration and fall velocity of estuarine particle populations using ADV, OBS and LISST, Continental Shelf Research, Volume 22, Issues 11-13, 2002 H.K. Ha, W.-Y. Hsu, J.P.-Y. Maa, Y.Y. Shao, C.W. Holland, Using ADV backscatter strength for measuring suspended cohesive sediment concentration, Continental Shelf Research, Volume 29, Issue 10, 2009 Hubert Chanson, Maiko Takeuchi, Mark Trevethan, Using turbidity and acoustic backscatter intensity as surrogate measures of

Solid waste management practices in wet coffee processing industries of Gidabo watershed, Ethiopia.

Science.gov (United States)

Ulsido, Mihret D; Li, Meng

2016-07-01

The financial and social contributions of coffee processing industries within most coffee export-based national economies like Ethiopia are generally high. The type and amount of waste produced and the waste management options adopted by these industries can have negative effects on the environment. This study investigated the solid waste management options adopted in wet coffee processing industries in the Gidabo watershed of Ethiopia. A field observation and assessment were made to identify whether the operational characteristics of the industries have any effect on the waste management options that were practiced. The investigation was conducted on 125 wet coffee processing industries about their solid waste handling techniques. Focus group discussion, structured questionnaires, key informant interview and transect walks are some of the tools employed during the investigation. Two major types of wastes, namely hull-bean-pulp blended solid waste and wastewater rich in dissolved and suspended solids were generated in the industries. Wet mills, on average, released 20.69% green coffee bean, 18.58% water and 60.74% pulp by weight. Even though these wastes are rich in organic matter and recyclables; the most favoured solid waste management options in the watershed were disposal (50.4%) and industrial or household composting (49.6%). Laxity and impulsive decision are the driving motives behind solid waste management in Gidabo watershed. Therefore, to reduce possible contamination of the environment, wastes generated during the processing of red coffee cherries, such as coffee wet mill solid wastes, should be handled properly and effectively through maximisation of their benefits with minimised losses. © The Author(s) 2016.

KINETICS OF SUSPENDED EMULSION POLYMERIZATION OF METHYL METHACRYLATE

Institute of Scientific and Technical Information of China (English)

Yong-zhong Bao; Cheng-xi Wang; Zhi-ming Huang; Zhi-xue Weng

2004-01-01

The kinetics of suspended emulsion polymerization of methyl methacrylate (MMA), in which water acted as the dispersed phase and the mixture of MMA and cyclohexane as the continuous phase, was investigated. It showed that the initial polymerization rate (Rp0) and steady-state polymerization rate (Rp) were proportional to the mass ratio between water and oil phase, and increased as the polymerization temperature, the potassium persulphate concentration ([I]) and the Tween20 emulsifier concentration ([S]) increased. The relationships between the polymerization rate and [I] and [S] were obtained as follows: Rp0 ∝ [I]0.73[S]0.32 and Rp ∝ [I]0.71[S]0.23. The above exponents were close to those obtained from normal MMA emulsion polymerization. It also showed that the average molecular weight of the resulting poly(methyl methacrylate) decreased as the polymerization temperature, [I] and [S] increased. Thus, MMA suspended emulsion polymerization could be considered as a combination of many miniature emulsion polymerizations proceeding in water drops and obeyed the classical kinetics of MMA emulsion polymerization.

Particles of bottom and suspended sediments: height of rise

Directory of Open Access Journals (Sweden)

Khodzinskaya Anna Gennadievna

2014-12-01

Full Text Available In the article, characteristic values of dynamic sizes of bottom and suspended sediments, including their probabilistic assessment, are considered. The article presents the processing results in respect of the experimental data for bottom and suspended sediments, obtained in the laboratory environment using samples and filming methods. The experiments have proven that the dynamic hydraulic size determines the height of rise for the particles of the saltation load, rather than suspended ones. In the laboratory environment, the maximal height of rise is mainly driven by the relative flow depth. According to the assessment made by the co-authors, depths of flows employed in the experiments designated for the identification of heights of rises, were comparable to saltation heights of particles. Besides, the saltation height of particles, having relative density well below 2.65, nearly always exceeded half of the depth of the laboratory flow. Hydrodynamic conditions favourable for the separation and motion of artificial particles in coarse surface tanks are far different from the motion of sand particles on the bottom of lowland rivers. Values of hydraulic resistance ratios typical for laboratory experiments by far exceed their values typical for lowland rivers, and it means that the conditions of the experiments performed in the laboratory were similar to those typical for mountain rivers. The research findings have proven that the particle separation and motion pattern, if artificial particles are made of the materials demonstrating variable density and elasticity values and if loose particles travel over fixed ones, is different from the pattern typical for natural particles having variable coarseness.

Seasonal variations in suspended-sediment dynamics in the tidal reach of an estuarine tributary

Science.gov (United States)

Downing-Kunz, Maureen A.; Schoellhamer, David H.

2013-01-01

Quantifying sediment supply from estuarine tributaries is an important component of developing a sediment budget, and common techniques for estimating supply are based on gages located above tidal influence. However, tidal interactions near tributary mouths can affect the magnitude and direction of sediment supply to the open waters of the estuary. We investigated suspended-sediment dynamics in the tidal reach of Corte Madera Creek, an estuarine tributary of San Francisco Bay, using moored acoustic and optical instruments. Flux of both water and suspended-sediment were calculated from observed water velocity and turbidity for two periods in each of wet and dry seasons during 2010. During wet periods, net suspended-sediment flux was seaward; tidally filtered flux was dominated by the advective component. In contrast, during dry periods, net flux was landward; tidally filtered flux was dominated by the dispersive component. The mechanisms generating this landward flux varied; during summer we attributed wind–wave resuspension in the estuary and subsequent transport on flood tides, whereas during autumn we attributed increased spring tide flood velocity magnitude leading to local resuspension. A quadrant analysis similar to that employed in turbulence studies was developed to summarize flux time series by quantifying the relative importance of sediment transport events. These events are categorized by the direction of velocity (flood vs. ebb) and the magnitude of concentration relative to tidally averaged conditions (relatively turbid vs. relatively clear). During wet periods, suspended-sediment flux was greatest in magnitude during relatively turbid ebbs, whereas during dry periods it was greatest in magnitude during relatively turbid floods. A conceptual model was developed to generalize seasonal differences in suspended-sediment dynamics; model application to this study demonstrated the importance of few, relatively large events on net suspended-sediment flux

Evaluation of the Suspending Properties of the Coprecipitate of ...

African Journals Online (AJOL)

The suspending ability of the different ratios was evaluated in magnesium trisilicate suspension, and compared with a suspension prepared with Compound Tragacanth Powder BP (CTP) as well as a commercially available magnesium trisilicate suspension (MTS). The parameters tested were sedimentation rate, flow rate, ...

77 FR 70142 - Initialed Draft Revision to the Agreement Suspending the Antidumping Investigation on Certain Hot...

Science.gov (United States)

2012-11-23

... the Agreement Suspending the Antidumping Investigation on Certain Hot-Rolled Flat-Rolled Carbon... revision to the Agreement Suspending the Antidumping Investigation on Certain Hot-Rolled Flat-Rolled Carbon...'') investigation on hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from the Russian...

THE HYDROLOGIC CYCLE, UNIDIRECTIONAL CHARTER OF THE DISSOLVED SALTS AND SUSPENDED LOAD

Directory of Open Access Journals (Sweden)

Nicolae Florea

2012-12-01

Full Text Available In this paper it is underlined that the hydrologic cycle in nature, reversible and regenerating of fresh water, carries out also an unidirectional and irreversible circulation – by means of a fragment of the hydrologic cycle – of the dissolved salts and stream’s suspended load, entailed by the water drained from continents to ocean. The trend is to transfer soluble salts from land to ocean in the same time with the running water on land in the portion of the hydrologic cycle which refers to the water transfer from continents to ocean in order to equilibrate the annual water balance of the hydrologic cycle. But, one can realize here and there some local salt accumulations in salt soils or in salt lakes within areas without drainage in arid climate; these salts accumulations are cases of local hydrologic cycles „grafted” along the way of water on land (to ocean. The energy necessary to the hydrologic cycle in nature is delivered by the Sun, and the entropy remains at a low level as a consequence of the elimination in this cycle of water vapors with high entropy, and of the receiving of liquid or solid water with low entropy, so that the annual level of entropy is maintained at a low level.

Observation of Van Hove Singularities and Temperature Dependence of Electrical Characteristics in Suspended Carbon Nanotube Schottky Barrier Transistors

Science.gov (United States)

Zhang, Jian; Liu, Siyu; Nshimiyimana, Jean Pierre; Deng, Ya; Hu, Xiao; Chi, Xiannian; Wu, Pei; Liu, Jia; Chu, Weiguo; Sun, Lianfeng

2018-06-01

A Van Hove singularity (VHS) is a singularity in the phonon or electronic density of states of a crystalline solid. When the Fermi energy is close to the VHS, instabilities will occur, which can give rise to new phases of matter with desirable properties. However, the position of the VHS in the band structure cannot be changed in most materials. In this work, we demonstrate that the carrier densities required to approach the VHS are reached by gating in a suspended carbon nanotube Schottky barrier transistor. Critical saddle points were observed in regions of both positive and negative gate voltage, and the conductance flattened out when the gate voltage exceeded the critical value. These novel physical phenomena were evident when the temperature is below 100 K. Further, the temperature dependence of the electrical characteristics was also investigated in this type of Schottky barrier transistor.

Suspended sediment transport in the Gulf of Lions (NW Mediterranean): Impact of extreme storms and floods

NARCIS (Netherlands)

Ulses, C.; Estournel, C.; Durrieu de Madron, X.; Palanques, A.

2008-01-01

In situ observations were combined with 3D modeling to gain understanding of and to quantify the suspended sediment transport in the Gulf of Lions (NW Mediterranean Sea). The outputs of a hydrodynamic–sediment transport coupled model were compared to near-bottom current and suspended sediment

Sampled control of vibration in suspended cask by using vibration manipulation functions

International Nuclear Information System (INIS)

Kotake, Shigeo

2014-01-01

Safe and reliable operation is most important for decommissioning the Fukushima 1 nuclear power plant. Especially it requires for transferring spent nuclear fuels from fuel pool to storage cask. Since the heavy cask will be suspended during the transferring operation, there is a risk of dropping it in case of the strike of large earthquakes. In this study, we introduce analytical functions to suppress residual vibration of a suspended cask by using vibration manipulation function. Hence the oscillation of the cask can be feedforward or sampled-data controlled by moving a trolley with analog actuator, the possible risk could be reduced. (author)

Graphene-based structure, method of suspending graphene membrane, and method of depositing material onto graphene membrane

Science.gov (United States)

Zettl, Alexander K.; Meyer, Jannik Christian

2013-04-02

An embodiment of a method of suspending a graphene membrane across a gap in a support structure includes attaching graphene to a substrate. A pre-fabricated support structure having the gap is attached to the graphene. The graphene and the pre-fabricated support structure are then separated from the substrate which leaves the graphene membrane suspended across the gap in the pre-fabricated support structure. An embodiment of a method of depositing material includes placing a support structure having a graphene membrane suspended across a gap under vacuum. A precursor is adsorbed to a surface of the graphene membrane. A portion of the graphene membrane is exposed to a focused electron beam which deposits a material from the precursor onto the graphene membrane. An embodiment of a graphene-based structure includes a support structure having a gap, a graphene membrane suspended across the gap, and a material deposited in a pattern on the graphene membrane.

Dynamics of suspended sediment load in the upper part of the Rasina River Basin in 2010

Directory of Open Access Journals (Sweden)

Mustafić Sanja

2013-01-01

Full Text Available The paper treats the issue of the suspended sediment load transport in the upper part of the Rasina River Basin, upstream from the "Ćelije" reservoir during the year of 2010. Measurements of the suspended sediment concentrations were being done at two hydrological profiles Brus and Ravni. Total quantity of the suspended sediment load that was transported at the profile of Brus in 2010 amounted to 3,437.3 t, which gave the specific transport of 16.4 t/km2/year. At the downstream profile of Ravni, 43,165 t of the suspended sediment load was transported, that is, 95.7 t/km2/year. The basin on the whole is characterized by the existence of two seasons, which by their characteristics in the load transport represent the extreme variants. During the winter-spring season, 74-85.8 % of the total annual load was transported, аnd during the summer-autumn season between 14.2 and 26 %.

A Case Study of Dynamic Response Analysis and Safety Assessment for a Suspended Monorail System.

Science.gov (United States)

Bao, Yulong; Li, Yongle; Ding, Jiajie

2016-11-10

A suspended monorail transit system is a category of urban rail transit, which is effective in alleviating traffic pressure and injury prevention. Meanwhile, with the advantages of low cost and short construction time, suspended monorail transit systems show vast potential for future development. However, the suspended monorail has not been systematically studied in China, and there is a lack of relevant knowledge and analytical methods. To ensure the health and reliability of a suspended monorail transit system, the driving safety of vehicles and structure dynamic behaviors when vehicles are running on the bridge should be analyzed and evaluated. Based on the method of vehicle-bridge coupling vibration theory, the finite element method (FEM) software ANSYS and multi-body dynamics software SIMPACK are adopted respectively to establish the finite element model for bridge and the multi-body vehicle. A co-simulation method is employed to investigate the vehicle-bridge coupling vibration for the transit system. The traffic operation factors, including train formation, track irregularity and tire stiffness, are incorporated into the models separately to analyze the bridge and vehicle responses. The results show that the coupling of dynamic effects of the suspended monorail system between vehicle and bridge are significant in the case studied, and it is strongly suggested to take necessary measures for vibration suppression. The simulation of track irregularity is a critical factor for its vibration safety, and the track irregularity of A-level road roughness negatively influences the system vibration safety.

A Case Study of Dynamic Response Analysis and Safety Assessment for a Suspended Monorail System

Directory of Open Access Journals (Sweden)

Yulong Bao

2016-11-01

Full Text Available A suspended monorail transit system is a category of urban rail transit, which is effective in alleviating traffic pressure and injury prevention. Meanwhile, with the advantages of low cost and short construction time, suspended monorail transit systems show vast potential for future development. However, the suspended monorail has not been systematically studied in China, and there is a lack of relevant knowledge and analytical methods. To ensure the health and reliability of a suspended monorail transit system, the driving safety of vehicles and structure dynamic behaviors when vehicles are running on the bridge should be analyzed and evaluated. Based on the method of vehicle-bridge coupling vibration theory, the finite element method (FEM software ANSYS and multi-body dynamics software SIMPACK are adopted respectively to establish the finite element model for bridge and the multi-body vehicle. A co-simulation method is employed to investigate the vehicle-bridge coupling vibration for the transit system. The traffic operation factors, including train formation, track irregularity and tire stiffness, are incorporated into the models separately to analyze the bridge and vehicle responses. The results show that the coupling of dynamic effects of the suspended monorail system between vehicle and bridge are significant in the case studied, and it is strongly suggested to take necessary measures for vibration suppression. The simulation of track irregularity is a critical factor for its vibration safety, and the track irregularity of A-level road roughness negatively influences the system vibration safety.

Influences of channelization on discharge of suspended sediment and wetland vegetation in Kushiro Marsh, northern Japan

Science.gov (United States)

Nakamura, Futoshi; Sudo, Tadashi; Kameyama, Satoshi; Jitsu, Mieko

1997-03-01

The effects of wetlands on hydrology, water quality, and wildlife habitat are internationally recognized. Protecting the remaining wetlands is one of the most important environmental issues in many countries. However wetlands in Japan have been gradually shrinking due to agricultural development and urbanization, which generally lowers the groundwater level and introduces suspended sediment and sediment-associated nutrients into wetlands. We examined the influences of channelization on discharge of suspended sediment and wetland vegetation in Hokkaido, northern Japan. The impact of river channelization was confirmed not only by the sediment budgets but also by river aggradation or degradation after the channelization and by the resultant vegetational changes. The budgets of suspended sediment demonstrated that wash load was the predominant component accounting for 95% of the total suspended load delivered into the wetland. This suspended sediment was primarily transported into the wetland by flooding associated with heavy rainfall. Twenty-three percent of the wash load and 63% of the suspended bed material load were deposited in the channelized reach, which produced aggradation of about 2 m at the end of the reach. A shorting of the length of the channel, due to channelization of a meandering river, steepened the slope and enhanced the stream power to transport sediment. This steepening shifted the depositional zones of fine sediment 5 km downstream and aggraded the riverbed. Development of the watershed may increase not only the water discharge but also the amount of suspended sediments. The aggradation reduced the carrying capacity of the channel and caused sediment ladened water to flood over the wetlands. The fine sediment accumulated on the wetlands gradually altered the edaphic conditions and wetland vegetation. A low percentage (10 to 15%) of organic contents of wetlands' soil is more evidence indicating that the present condition is far different from

Low-stress photosensitive polyimide suspended membrane for improved thermal isolation performance

Science.gov (United States)

Fan, J.; Xing, R. Y.; Wu, W. J.; Liu, H. F.; Liu, J. Q.; Tu, L. C.

2017-11-01

In this paper, we introduce a method of isolating thermal conduction from silicon substrate for accommodating thermal-sensitive micro-devices. This method lies in fabrication of a low-stress photosensitive polyimide (PSPI) suspension structure which has lower thermal conductivity than silicon. First, a PSPI layer was patterned on a silicon wafer and hard baked. Then, a cavity was etched from the backside of the silicon substrate to form a membrane or a bridge-shape PSPI structure. After releasing, a slight deformation of about 20 nm was observed in the suspended structures, suggesting ultralow residual stress which is essential for accommodating micro-devices. In order to investigate the thermal isolation performance of the suspended PSPI structures, micro Pirani vacuum gauges, which are thermal-sensitive, had been fabricated on the PSPI structures. The measurement results illustrated that the Pirani gauges worked as expected in the range from 1- 470 Pa. Moreover, the results of the Pirani gauges based on the membrane and bridge structures were comparable, indicating that the commonly used bridge-shape structure for further reducing thermal conduction was unnecessary. Due to the excellent thermal isolation performance of PSPI, the suspended PSPI membrane is promising to be an outstanding candidate for thermal isolation applications.

Climate-scale modelling of suspended sediment load in an Alpine catchment debris flow (Rio Cordon-northeastern Italy)

Science.gov (United States)

Diodato, Nazzareno; Mao, Luca; Borrelli, Pasquale; Panagos, Panos; Fiorillo, Francesco; Bellocchi, Gianni

2018-05-01

Pulsing storms and prolonged rainfall can drive hydrological damaging events in mountain regions with soil erosion and debris flow in river catchments. The paper presents a parsimonious model for estimating climate forcing on sediment loads in an Alpine catchment (Rio Cordon, northeastern Italian Alps). Hydroclimatic forcing was interpreted by the novel CliSMSSL (Climate-Scale Modelling of Suspended Sediment Load) model to estimate annual sediment loads. We used annual data on suspended-solid loads monitored at an experimental station from 1987 to 2001 and on monthly precipitation data. The quality of sediment load data was critically examined, and one outlying year was identified and removed from further analyses. This outlier revealed that our model underestimates exceptionally high sediment loads in years characterized by a severe flood event. For all other years, the CliSMSSL performed well, with a determination coefficient (R2) equal to 0.67 and a mean absolute error (MAE) of 129 Mg y-1. The calibrated model for the period 1986-2010 was used to reconstruct sediment loads in the river catchment for historical times when detailed precipitation records are not available. For the period 1810-2010, the model results indicate that the past centuries have been characterized by large interannual to interdecadal fluctuations in the conditions affecting sediment loads. This paper argues that climate-induced erosion processes in Alpine areas and their impact on environment should be given more attention in discussions about climate-driven strategies. Future work should focus on delineating the extents of these findings (e.g., at other catchments of the European Alpine belt) as well as investigating the dynamics for the formation of sediment loads.

Novel Resuscitation from Lethal Hemorrhage-Suspended Animation for Delayed Resuscitation

National Research Council Canada - National Science Library

Safar, Peter

2003-01-01

...). We have conceived and documented the concept of "suspended animation (SA) for delayed resuscitation" using a hypothermic saline flush into the aorta within the first 5 min of CA, using novel clinically relevant outcome models in dogs...

A Spatially Distributed Conceptual Model for Estimating Suspended Sediment Yield in Alpine catchments

Science.gov (United States)

Costa, Anna; Molnar, Peter; Anghileri, Daniela

2017-04-01

Suspended sediment is associated with nutrient and contaminant transport in water courses. Estimating suspended sediment load is relevant for water-quality assessment, recreational activities, reservoir sedimentation issues, and ecological habitat assessment. Suspended sediment concentration (SSC) along channels is usually reproduced by suspended sediment rating curves, which relate SSC to discharge with a power law equation. Large uncertainty characterizes rating curves based only on discharge, because sediment supply is not explicitly accounted for. The aim of this work is to develop a source-oriented formulation of suspended sediment dynamics and to estimate suspended sediment yield at the outlet of a large Alpine catchment (upper Rhône basin, Switzerland). We propose a novel modelling approach for suspended sediment which accounts for sediment supply by taking into account the variety of sediment sources in an Alpine environment, i.e. the spatial location of sediment sources (e.g. distance from the outlet and lithology) and the different processes of sediment production and transport (e.g. by rainfall, overland flow, snowmelt). Four main sediment sources, typical of Alpine environments, are included in our model: glacial erosion, hillslope erosion, channel erosion and erosion by mass wasting processes. The predictive model is based on gridded datasets of precipitation and air temperature which drive spatially distributed degree-day models to simulate snowmelt and ice-melt, and determine erosive rainfall. A mass balance at the grid scale determines daily runoff. Each cell belongs to a different sediment source (e.g. hillslope, channel, glacier cell). The amount of sediment entrained and transported in suspension is simulated through non-linear functions of runoff, specific for sediment production and transport processes occurring at the grid scale (e.g. rainfall erosion, snowmelt-driven overland flow). Erodibility factors identify different lithological units

Characterizing suspended sediments from the Piracicaba River Basin by means of k0-INAA

International Nuclear Information System (INIS)

Franca, E.J.; Fernandes, E.A.N.; Cavalca, I.P.O; Fonseca, F.Y.; Camilli, L.; Rodrigues, V.S.; Bardini Junior, C.; Ferreira, J.R.; Bacchi, M.A.

2010-01-01

The inorganic chemical characterization of suspended sediments is of utmost relevance for the knowledge of the dynamics and movement of chemical elements in the aquatic and wet ecosystems. Despite the complexity of the effective design for studying this ecological compartment, this work has tested a procedure for analyzing suspended sediments by instrumental neutron activation analysis, k 0 method (k 0 -INAA). The chemical elements As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, Hg, K, La, Mo, Na, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Yb and Zn were quantified in the suspended sediment compartment by means of k 0 -INAA. When compared with World Average for rivers, high mass fractions of Fe (222,900 mg/kg), Ba (4990 mg/kg), Zn (1350 mg/kg), Cr (646 mg/kg), Co (74.5 mg/kg), Br (113 mg/kg) and Mo (31.9 mg/kg) were quantified in suspended sediments from the Piracicaba River, the Piracicamirim Stream and the Marins Stream. Results of the principal component analysis for standardized chemical element mass fractions indicated an intricate correlation among chemical elements evaluated, as a response of the contribution of natural and anthropogenic sources of chemical elements for ecosystems.

Reduction in density of suspended - sediment - laden natural waters

Digital Repository Service at National Institute of Oceanography (India)

Joseph, A.; Desa, E.; Desa, E.; Smith, D.; Peshwe, V.B.; VijayKumar, K.; Desa, J.A.E.

to 0.4% - 4.5%) that of the density of the same water without suspended sediment. Teh values of peff in a given site differed from one tidal cycle to another (approx equal to 1.9%). These values varied slightly (less than 0.8%) from mid-tide to slack...

Validation of a low field Rheo-NMR instrument and application to shear-induced migration of suspended non-colloidal particles in Couette flow

Science.gov (United States)

Colbourne, A. A.; Blythe, T. W.; Barua, R.; Lovett, S.; Mitchell, J.; Sederman, A. J.; Gladden, L. F.

2018-01-01

Nuclear magnetic resonance rheology (Rheo-NMR) is a valuable tool for studying the transport of suspended non-colloidal particles, important in many commercial processes. The Rheo-NMR imaging technique directly and quantitatively measures fluid displacement as a function of radial position. However, the high field magnets typically used in these experiments are unsuitable for the industrial environment and significantly hinder the measurement of shear stress. We introduce a low field Rheo-NMR instrument (1 H resonance frequency of 10.7MHz), which is portable and suitable as a process monitoring tool. This system is applied to the measurement of steady-state velocity profiles of a Newtonian carrier fluid suspending neutrally-buoyant non-colloidal particles at a range of concentrations. The large particle size (diameter > 200 μm) in the system studied requires a wide-gap Couette geometry and the local rheology was expected to be controlled by shear-induced particle migration. The low-field results are validated against high field Rheo-NMR measurements of consistent samples at matched shear rates. Additionally, it is demonstrated that existing models for particle migration fail to adequately describe the solid volume fractions measured in these systems, highlighting the need for improvement. The low field implementation of Rheo-NMR is complementary to shear stress rheology, such that the two techniques could be combined in a single instrument.

River suspended sediment estimation by climatic variables implication: Comparative study among soft computing techniques

Science.gov (United States)

Kisi, Ozgur; Shiri, Jalal

2012-06-01

Estimating sediment volume carried by a river is an important issue in water resources engineering. This paper compares the accuracy of three different soft computing methods, Artificial Neural Networks (ANNs), Adaptive Neuro-Fuzzy Inference System (ANFIS), and Gene Expression Programming (GEP), in estimating daily suspended sediment concentration on rivers by using hydro-meteorological data. The daily rainfall, streamflow and suspended sediment concentration data from Eel River near Dos Rios, at California, USA are used as a case study. The comparison results indicate that the GEP model performs better than the other models in daily suspended sediment concentration estimation for the particular data sets used in this study. Levenberg-Marquardt, conjugate gradient and gradient descent training algorithms were used for the ANN models. Out of three algorithms, the Conjugate gradient algorithm was found to be better than the others.

Approximate Series Solutions for Nonlinear Free Vibration of Suspended Cables

Directory of Open Access Journals (Sweden)

Yaobing Zhao

2014-01-01

Full Text Available This paper presents approximate series solutions for nonlinear free vibration of suspended cables via the Lindstedt-Poincare method and homotopy analysis method, respectively. Firstly, taking into account the geometric nonlinearity of the suspended cable as well as the quasi-static assumption, a mathematical model is presented. Secondly, two analytical methods are introduced to obtain the approximate series solutions in the case of nonlinear free vibration. Moreover, small and large sag-to-span ratios and initial conditions are chosen to study the nonlinear dynamic responses by these two analytical methods. The numerical results indicate that frequency amplitude relationships obtained with different analytical approaches exhibit some quantitative and qualitative differences in the cases of motions, mode shapes, and particular sag-to-span ratios. Finally, a detailed comparison of the differences in the displacement fields and cable axial total tensions is made.

24 CFR 1000.44 - What prohibitions on the use of debarred, suspended, or ineligible contractors apply?

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false What prohibitions on the use of debarred, suspended, or ineligible contractors apply? 1000.44 Section 1000.44 Housing and Urban Development... § 1000.44 What prohibitions on the use of debarred, suspended, or ineligible contractors apply? In...

Impact of robotics and a suspended lead suit on physician radiation exposure during percutaneous coronary intervention.

Science.gov (United States)

Madder, Ryan D; VanOosterhout, Stacie; Mulder, Abbey; Elmore, Matthew; Campbell, Jessica; Borgman, Andrew; Parker, Jessica; Wohns, David

Reports of left-sided brain malignancies among interventional cardiologists have heightened concerns regarding physician radiation exposure. This study evaluated the impact of a suspended lead suit and robotic system on physician radiation exposure during percutaneous coronary intervention (PCI). Real-time radiation exposure data were prospectively collected from dosimeters worn by operating physicians at the head- and chest-level during consecutive PCI cases. Exposures were compared in three study groups: 1) manual PCI performed with traditional lead apparel; 2) manual PCI performed using suspended lead; and 3) robotic PCI performed in combination with suspended lead. Among 336 cases (86.6% manual, 13.4% robotic) performed over 30weeks, use of suspended lead during manual PCI was associated with significantly less radiation exposure to the chest and head of operating physicians than traditional lead apparel (chest: 0.0 [0.1] μSv vs 0.4 [4.0] μSv, probotic PCI performed in combination with suspended lead was 0.0 [0.0] μSv, which was significantly less chest exposure than manual PCI performed with traditional lead (probotic PCI the median head-level exposure was 0.1 [0.2] μSv, which was 99.3% less than manual PCI performed with traditional lead (probotics were observed to result in significantly less radiation exposure to the chest and head of operating physicians during PCI. Copyright © 2016 Elsevier Inc. All rights reserved.

IUTAM symposium on hydrodynamic diffusion of suspended particles

Energy Technology Data Exchange (ETDEWEB)

Davis, R.H. [ed.

1995-12-31

Hydrodynamic diffusion refers to the fluctuating motion of nonBrownian particles (or droplets or bubbles) which occurs in a dispersion due to multiparticle interactions. For example, in a concentrated sheared suspension, particles do not move along streamlines but instead exhibit fluctuating motions as they tumble around each other. This leads to a net migration of particles down gradients in particle concentration and in shear rate, due to the higher frequency of encounters of a test particle with other particles on the side of the test particle which has higher concentration or shear rate. As another example, suspended particles subject to sedimentation, centrifugation, or fluidization, do not generally move relative to the fluid with a constant velocity, but instead experience diffusion-like fluctuations in velocity due to interactions with neighboring particles and the resulting variation in the microstructure or configuration of the suspended particles. In flowing granular materials, the particles interact through direct collisions or contacts (rather than through the surrounding fluid); these collisions also cause the particles to undergo fluctuating motions characteristic of diffusion processes. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

Nature of suspended particulate matter and concentrations of heavy ...

African Journals Online (AJOL)

The concentrations of metals in bottom sediment in the Tanzanian waters of Lake Victoria and the nature of suspended particulate matter (SPM) were analysed. The objective of the study was to compare levels of metals in sediment from different locations and to establish their sources. Metal concentrations were higher in ...

Biological hydrogen production in continuous stirred tank reactor systems with suspended and attached microbial growth

Energy Technology Data Exchange (ETDEWEB)

Ren, Nan-Qi; Tang, Jing; Liu, Bing-Feng; Guo, Wan-Qian [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No.202 Haihe Road, Harbin 150090 (China)

2010-04-15

Fermentative H{sub 2} production in continuous stirred tank reactor (CSTR) system with bacteria attached onto granular activated carbon (GAC) was designed to produce H{sub 2} continuously. The H{sub 2} production performances of CSTR with suspended and attached-sludge from molasses were examined and compared at various organic loading rates (8-40 g COD/L/d) at hydraulic retention time of 6 h under mesophilic conditions (35 C). Both reactor systems achieved ethanol-type fermentation in the pH ranges 4.5-4.8 and 3.8-4.4, respectively, while ORP ranges from -450 to -470 mV and from -330 to -350 mV, respectively. The hydrogen production rate in the attached system was higher compared to that of the suspended system (9.72 and 6.65 L/d/L, respectively) while specific hydrogen production rate of 5.13 L/g VSS/d was higher in the suspended system. The attached-sludge CSTR is more stable than the suspended-sludge CSTR with regard to hydrogen production, pH, substrate utilization efficiency and metabolic products (e.g., volatile fatty acids and ethanol) during the whole test. (author)

Clean Transfer of Large Graphene Single Crystals for High-Intactness Suspended Membranes and Liquid Cells.

Science.gov (United States)

Zhang, Jincan; Lin, Li; Sun, Luzhao; Huang, Yucheng; Koh, Ai Leen; Dang, Wenhui; Yin, Jianbo; Wang, Mingzhan; Tan, Congwei; Li, Tianran; Tan, Zhenjun; Liu, Zhongfan; Peng, Hailin

2017-07-01

The atomically thin 2D nature of suspended graphene membranes holds promising in numerous technological applications. In particular, the outstanding transparency to electron beam endows graphene membranes great potential as a candidate for specimen support of transmission electron microscopy (TEM). However, major hurdles remain to be addressed to acquire an ultraclean, high-intactness, and defect-free suspended graphene membrane. Here, a polymer-free clean transfer of sub-centimeter-sized graphene single crystals onto TEM grids to fabricate large-area and high-quality suspended graphene membranes has been achieved. Through the control of interfacial force during the transfer, the intactness of large-area graphene membranes can be as high as 95%, prominently larger than reported values in previous works. Graphene liquid cells are readily prepared by π-π stacking two clean single-crystal graphene TEM grids, in which atomic-scale resolution imaging and temporal evolution of colloid Au nanoparticles are recorded. This facile and scalable production of clean and high-quality suspended graphene membrane is promising toward their wide applications for electron and optical microscopy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Validity of Lactate Thresholds in Inline Speed Skating.

Science.gov (United States)

Hecksteden, Anne; Heinze, Tobias; Faude, Oliver; Kindermann, Wilfried; Meyer, Tim

2015-09-01

Lactate thresholds are commonly used as estimates of the highest workload where lactate production and elimination are in equilibrium (maximum lactate steady state [MLSS]). However, because of the high static load on propulsive muscles, lactate kinetics in inline speed skating may differ significantly from other endurance exercise modes. Therefore, the discipline-specific validity of lactate thresholds has to be verified. Sixteen competitive inline-speed skaters (age: 30 ± 10 years; training per week: 10 ± 4 hours) completed an exhaustive stepwise incremental exercise test (start 24 km·h, step duration 3 minutes, increment 2 km·h) to determine individual anaerobic threshold (IAT) and the workload corresponding to a blood lactate concentration of 4 mmol·L (LT4) and 2-5 continuous load tests of (up to) 30 minutes to determine MLSS. The IAT and LT4 correlated significantly with MLSS, and the mean differences were almost negligible (MLSS 29.5 ± 2.5 km·h; IAT 29.2 ± 2.0 km·h; LT4 29.6 ± 2.3 km·h; p > 0.1 for all differences). However, the variability of differences was considerable resulting in 95% limits of agreement in the upper range of values known from other endurance disciplines (2.6 km·h [8.8%] for IAT and 3.1 km·h [10.3%] for LT4). Consequently, IAT and LT4 may be considered as valid estimates of the MLSS in inline speed skating, but verification by means of a constant load test should be considered in cases of doubt or when optimal accuracy is needed (e.g., in elite athletes or scientific studies).

Microscopic characterisation of suspended graphene grown by chemical vapour deposition

NARCIS (Netherlands)

Bignardi, L.; Dorp, W.F. van; Gottardi, S.; Ivashenko, O.; Dudin, P.; Barinov, A.; de Hosson, J.T.M.; Stöhr, M.; Rudolf, P.

2013-01-01

We present a multi-technique characterisation of graphene grown by chemical vapour deposition (CVD) and thereafter transferred to and suspended on a grid for transmission electron microscopy (TEM). The properties of the electronic band structure are investigated by angle-resolved photoelectron

Quantifying ratios of suspended sediment sources in forested headwater streams following timber-harvesting operations

Science.gov (United States)

Rachels, A. A.; Bladon, K. D.; Bywater-Reyes, S.

2017-12-01

Historically, timber-harvesting has increased fine sediment inputs to streams due to increased hillslope and streambank erosion and mass wasting along roads. However, under modern best management practices, the relative importance and variability of these sources is poorly understood. We present preliminary results from an ongoing study investigating the primary sources of suspended sediment in Oregon Coast Range streams influenced by timber harvesting. We instrumented two catchments, Enos Creek (harvested 2016) and Scheele Creek (reference) in fall 2016. Phillips samplers (5-6 per catchment) have been deployed longitudinally down the streams to enable robust characterization of suspended sediments—the collected samples integrate the chemical signatures of upstream sediment exports. We will collect samples monthly over 2 wet seasons and return to the laboratory to analyze the sediment using source fingerprinting approaches. The fingerprinting technique compares the chemical properties of stream sediment samples with the chemical properties of potential source areas, including 1) roads, 2) stream banks, and 3) hillslopes. To design a robust model for sediment-source identification, different types of chemical data are required—we will analyze sediment samples using a combination of: a) stable isotopes and C/N ratios (i.e., δ15N, δ13C, and C/N), b) geochemistry (Fe, K, and Ca), and c) radiogenic isotopes (137Cs and 210Pb). At the harvested site, the C/N ratios of the streambanks (17.9 ± 3.8) and the hillslopes (26.4 ± 4.8) are significantly different from one another (p = .016). C/N ratios of the suspended sediment (20.5 ± 2.0) are intermediate values between potential endmembers and behave conservatively with transport. The C/N ratios of the suspended sediment appear unaffected by roads (18.9 ± 8.7) along specific sections of the stream, suggesting that roads are not a primary sediment contributor. Under this assumption, the suspended sediment is, on

Promoting Therapists' Use of Motor Learning Strategies within Virtual Reality-Based Stroke Rehabilitation.

Directory of Open Access Journals (Sweden)

Danielle E Levac

Full Text Available Therapists use motor learning strategies (MLSs to structure practice conditions within stroke rehabilitation. Virtual reality (VR-based rehabilitation is an MLS-oriented stroke intervention, yet little support exists to assist therapists in integrating MLSs with VR system use.A pre-post design evaluated a knowledge translation (KT intervention incorporating interactive e-learning and practice, in which 11 therapists learned how to integrate MLSs within VR-based therapy. Self-report and observer-rated outcome measures evaluated therapists' confidence, clinical reasoning and behaviour with respect to MLS use. A focus group captured therapists' perspectives on MLS use during VR-based therapy provision.The intervention improved self-reported confidence about MLS use as measured by confidence ratings (p <0.001. Chart-Stimulated Recall indicated a moderate level of competency in therapists' clinical reasoning about MLSs following the intervention, with no changes following additional opportunities to use VR (p = .944. On the Motor Learning Strategy Rating Instrument, no behaviour change with respect to MLS use was noted (p = 0.092. Therapists favoured the strategy of transferring skills from VR to real-life tasks over employing a more comprehensive MLS approach.The KT intervention improved therapists' confidence but did not have an effect on clinical reasoning or behaviour with regard to MLS use during VR-based therapy.

Comparison Of Different Methods For The Swimming Aerobic Capacity Evaluation.

Science.gov (United States)

Pelarigo, Jailton Gregório; Fernandes, Ricardo Jorge; Ribeiro, João; Denadai, Benedito Sérgio; Greco, Camila Coelho; Vilas-Boas, João Paulo

2017-02-23

This study compared velocity (v) and bioenergetical factors using different methods applied for the swimming aerobic capacity evaluation. Ten elite female swimmers (17.6 ± 1.9 yrs., 1.70 ± 0.05 m and 61.3 ± 5.8 kg) performed an intermittent incremental velocity protocol until voluntary exhaustion to determine the v associated to the individual anaerobic threshold (IAnT), ventilatory threshold (VT), heart rate threshold (HRT), lactate threshold fixed in 3.5 mmol.L (LT3.5) and maximal oxygen uptake (V[Combining Dot Above]O2max). Two-to-three 30 min submaximal constant tests for the v assessment at maximal lactate steady state (MLSS). The v, gas exchange, heart rate and blood lactate concentration variables were monitored in all tests. The values of all parameters at the v corresponding to MLSS, IAnT, VT and HRT were similar (p 0.400), except for carbon dioxide (V[Combining Dot Above]CO2) that was higher for MLSS compared to VT (p higher when compared to other methods for v and bioenergetical factors. It is suggested that IAnT, VT and HRT methods are better predictors of the intensity corresponding to the commonly accepted gold-standard method (i.e. MLSS) for the aerobic capacity evaluation compared to LT3.5.

Degradation of phenol and TCE using suspended and chitosan-bead immobilized Pseudomonas putida.

Science.gov (United States)

Chen, Yan-Min; Lin, Tsair-Fuh; Huang, Chih; Lin, Jui-Che; Hsieh, Feng-Ming

2007-09-30

The degradability of phenol and trichloroethene (TCE) by Pseudomonas putida BCRC 14349 in both suspended culture and immobilized culture systems are investigated. Chitosan beads at a size of about 1-2mm were employed to encapsulate the P. putida cells, becoming an immobilized culture system. The phenol concentration was controlled at 100 mg/L, and that of TCE was studied from 0.2 to 20 mg/L. The pH, between 6.7 and 10, did not affect the degradation of either phenol or TCE in the suspended culture system. However, it was found to be an important factor in the immobilized culture system in which the only significant degradation was observed at pH >8. This may be linked to the surface properties of the chitosan beads and its influence on the activity of the bacteria. The transfer yield of TCE on a phenol basis was almost the same for the suspended and immobilized cultures (0.032 mg TCE/mg phenol), except that these yields occurred at different TCE concentrations. The transfer yield at a higher TCE concentration for the immobilized system suggested that the cells immobilized in carriers can be protected from harsh environmental conditions. For kinetic rate interpretation, the Monod equation was employed to describe the degradation rates of phenol, while the Haldane's equation was used for TCE degradation. Based on the kinetic parameters obtained from the two equations, the rate for the immobilized culture systems was only about 1/6 to that of the suspended culture system for phenol degradation, and was about 1/2 for TCE degradation. The slower kinetics observed for the immobilized culture systems was probably due to the slow diffusion of substrate molecules into the beads. However, compared with the suspended cultures, the immobilized cultures may tolerate a higher TCE concentration as much less inhibition was observed and the transfer yield occurred at a higher TCE concentration.

Daily Suspended Sediment Discharge Prediction Using Multiple Linear Regression and Artificial Neural Network

Science.gov (United States)

Uca; Toriman, Ekhwan; Jaafar, Othman; Maru, Rosmini; Arfan, Amal; Saleh Ahmar, Ansari

2018-01-01

Prediction of suspended sediment discharge in a catchments area is very important because it can be used to evaluation the erosion hazard, management of its water resources, water quality, hydrology project management (dams, reservoirs, and irrigation) and to determine the extent of the damage that occurred in the catchments. Multiple Linear Regression analysis and artificial neural network can be used to predict the amount of daily suspended sediment discharge. Regression analysis using the least square method, whereas artificial neural networks using Radial Basis Function (RBF) and feedforward multilayer perceptron with three learning algorithms namely Levenberg-Marquardt (LM), Scaled Conjugate Descent (SCD) and Broyden-Fletcher-Goldfarb-Shanno Quasi-Newton (BFGS). The number neuron of hidden layer is three to sixteen, while in output layer only one neuron because only one output target. The mean absolute error (MAE), root mean square error (RMSE), coefficient of determination (R2 ) and coefficient of efficiency (CE) of the multiple linear regression (MLRg) value Model 2 (6 input variable independent) has the lowest the value of MAE and RMSE (0.0000002 and 13.6039) and highest R2 and CE (0.9971 and 0.9971). When compared between LM, SCG and RBF, the BFGS model structure 3-7-1 is the better and more accurate to prediction suspended sediment discharge in Jenderam catchment. The performance value in testing process, MAE and RMSE (13.5769 and 17.9011) is smallest, meanwhile R2 and CE (0.9999 and 0.9998) is the highest if it compared with the another BFGS Quasi-Newton model (6-3-1, 9-10-1 and 12-12-1). Based on the performance statistics value, MLRg, LM, SCG, BFGS and RBF suitable and accurately for prediction by modeling the non-linear complex behavior of suspended sediment responses to rainfall, water depth and discharge. The comparison between artificial neural network (ANN) and MLRg, the MLRg Model 2 accurately for to prediction suspended sediment discharge (kg

Field calibration of optical sensors for measuring suspended sediment concentration in the western Mediterranean

Directory of Open Access Journals (Sweden)

J. Guillén

2000-12-01

Full Text Available The water turbidity measured with optical methods (transmittance and backscattering is usually expressed as beam attenuation coefficient (BAC or formazin turbidity units (FTU. The transformation of these units to volumetric suspended sediment concentration (SSC units is not straightforward, and accurate calibrations are required in order to obtain valuable information on suspended sediment distributions and fluxes. In this paper, data from field calibrations between BAC, FTU and SSC are presented and best-fit calibration curves are shown. These calibrations represent an average from different marine environments of the western Mediterranean (from estuary to continental slope. However, the general curves can only be applied for descriptive or semi-quantitative purposes. Comparison of turbidity measurements using the same sensor with different calibration ranges shows the advantage of simultaneously combining two instruments calibrated in different ranges when significant changes in suspended sediment concentrations are expected.

Finite Element Analysis of the Rotor System of a Magnetically Suspended Compound Molecule Pump

International Nuclear Information System (INIS)

Liu Pingfan; Zhao Lei; Shi Zhengang; Yang Guojun

2014-01-01

A novel magnetically suspended compound molecule pump has been designed, which has been supported by the active magnetic bearings (AMBs) system with 5 degrees of freedom. According to the characteristics of the high speed and AMBs, the rotor system of the magnetically suspended compound molecule pump has been analyzed by the finite element method. Modal analysis has been performed for the rotor, thus modal frequencies and corresponding modal shapes have been obtained. For the high rotating speed the blades usually have tended to be destroyed as the results of the centrifugal deformation and vibration. So several static parameters have been analyzed, such as stress distributions and deformations. Simulation results provide a theoretical foundation for the design of the magnetically suspended compound molecule pump’s controllers. The reliability and safety of the structure have been verified completely. Furthermore, this paper is of great significance for the pumps’ future developments. (author)

[Characteristics and its forming mechanism on grain size distribution of suspended matter at Changjiang Estuary].

Science.gov (United States)

Pang, Chong-guang; Yu, Wei; Yang, Yang

2010-03-01

In July of 2008, under the natural condition of sea water, the Laser in-situ scattering and transmissometry (LISST-100X Type C) was used to measure grain size distribution spectrum and volume concentration of total suspended matter in the sea water, including flocs at different layers of 24 sampling stations at Changjiang Estuary and its adjacent sea. The characteristics and its forming mechanism on grain size distribution of total suspended matter were analyzed based on the observation data of LISST-100X Type C, and combining with the temperature, salinity and turbidity of sea water, simultaneously observed by Alec AAQ1183. The observation data showed that the average median grain size of total suspended matter was about 4.69 phi in the whole measured sea area, and the characteristics of grain size distribution was relatively poor sorted, wide kurtosis, and basically symmetrical. The conclusion could be drawn that vertically average volume concentration decreased with the distance from the coastline, while median grain size had an increase trend with the distance, for example, at 31.0 degrees N section, the depth-average median grain size had been increased from 11 microm up to 60 microm. With the increasing of distance from the coast, the concentration of fine suspended sediment reduced distinctly, nevertheless some relatively big organic matter or big flocs appeared in quantity, so its grain size would rise. The observation data indicated that the effective density was ranged from 246 kg/m3 to 1334 kg/m, with average was 613 kg/m3. When the concentration of total suspended matter was relatively high, median grain size of total suspended matter increased with the water depth, while effective density decreased with the depth, because of the faster settling velocity and less effective density of large flocs that of small flocs. As for station 37 and 44, their correlation coefficients between effective density and median grain size were larger than 0.9.

76 FR 38694 - Uranium From Russia; Institution of a Five-Year Review Concerning the Suspended Investigation on...

Science.gov (United States)

2011-07-01

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-539-C (Third Review)] Uranium From Russia; Institution of a Five-Year Review Concerning the Suspended Investigation on Uranium From Russia AGENCY: United...)) (the Act) to determine whether termination of the suspended investigation on uranium from Russia would...

Consequences of hydrological events on the delivery of suspended sediment and associated radionuclides from the Rhone River to the Mediterranean Sea

Energy Technology Data Exchange (ETDEWEB)

Eyrolle, Frederique; Antonelli, Christelle; Ferrand, Emmanuelle [IRSN, Saint Paul Lez Durance (France). Pole Radioprotection environnement, dechets et crise, PRP-ENV, Service d' Etude et de Surveillance de la Radioactivite dans l' Environnement; Raimbault, Patrick [Institut Mediterraneen d' Oceanologie, OSU Pytheas, Marseille (France); Aubert, Dominique [CEFREM, Univ. de Perpignan Via Domitia CNRS UMR, Perpignan (France); Jacquet, Stephanie; Radakovitch, Olivier; Raccasi, Guillaume [Aix-Marseille Univ.-CNR-IRD-College de France, Aix en Provence (France); Charmasson, Sabine [IRSN, La Seyne sur mer (France). Pole Radioprotection, environnement, dechets et crise, PRP-ENV, Service d' Etude et de Surveillance de la Radioactivite dans l' Environnement; Gurriaran, Rodolfo [IRSN, Orsay (France). Pole Radioprotection, environnement, dechets et crise, PRP-ENV, Service de Traitement des echantillos et de Metrologie pour l' Environnement

2012-10-15

level and fate of suspended solids and radionuclide concentrations during flood events occurring in a large river system that could be contaminated by chronic or accidental radioactive releases. These results are of fundamental importance for further interpretations of sediment dynamics at the river mouth.

Experimental investigations of heat transfer in thermo active building systems in combination with suspended ceilings

DEFF Research Database (Denmark)

Alvarez, Maria Alonso; Hviid, Christian Anker; Weitzmann, Peter

2014-01-01

buildings to cover acoustic requirements hinders the use of TABS. To measure the reduction of the heat capacity, several experiments are performed in a room equipped with TABS in the upper deck and mixing ventilation. The heat transfer is measured for different suspended ceiling covering percentages...... that the ventilation rate has a high influence on the convective heat capacity. When the ventilation rate is increased from 1.7 h-1 to 2.9 h-1, the heat transfer coefficient increases up to 16% for the same occupancy and suspended ceiling layout.......Thermo Active Building Systems (TABS), described as radiant heating or cooling systems with pipes embedded in the building structure, represent a sustainable alternative to replace conventional systems by using source temperatures close to room temperatures. The use of suspended ceiling in office...

An overview of municipal solid waste management and landfill leachate treatment: Malaysia and Asian perspectives.

Science.gov (United States)

Kamaruddin, Mohamad Anuar; Yusoff, Mohd Suffian; Rui, Lo Ming; Isa, Awatif Md; Zawawi, Mohd Hafiz; Alrozi, Rasyidah

2017-12-01

Currently, generation of solid waste per capita in Malaysia is about 1.1 kg/day. Over 26,500 t of solid waste is disposed almost solely through 166 operating landfills in the country every day. Despite the availability of other disposal methods, landfill is the most widely accepted and prevalent method for municipal solid waste (MSW) disposal in developing countries, including Malaysia. This is mainly ascribed to its inherent forte in terms cost saving and simpler operational mechanism. However, there is a downside. Environmental pollution caused by the landfill leachate has been one of the typical dilemmas of landfilling method. Leachate is the liquid produced when water percolates through solid waste and contains dissolved or suspended materials from various disposed materials and biodecomposition processes. It is often a high-strength wastewater with extreme pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), inorganic salts and toxicity. Its composition differs over the time and space within a particular landfill, influenced by a broad spectrum of factors, namely waste composition, landfilling practice (solid waste contouring and compacting), local climatic conditions, landfill's physico-chemical conditions, biogeochemistry and landfill age. This paper summarises an overview of landfill operation and leachate treatment availability reported in literature: a broad spectrum of landfill management opportunity, leachate parameter discussions and the way forward of landfill leachate treatment applicability.

Evaluation of the suspending properties of Cola acuminata gum on ...

African Journals Online (AJOL)

Calamine suspensions were formulated with CAG between the concentration range of 1 – 4 % w/v and compared with suspensions formulated with two standard suspending agents (tragacanth and acacia gums). Sedimentation volume, flow rate, rheology and redispersibility were used as evaluating parameters.

Heavy metal toxicity and bioavailability of dissolved nutrients to a bacterivorous flagellate are linked to suspended particle physical properties

International Nuclear Information System (INIS)

Boenigk, Jens; Wiedlroither, Anneliese; Pfandl, Karin

2005-01-01

Many dissolved substances attach easily to sediment particles. In the presence of suspended sediments bioavailability of dissolved substances is therefore, usually reduced and clays are even applied to 'wash' natural waters upon pollution. In organisms which feed on food organisms in the size range of these suspended sediment particles, however, bioavailability of such substances may even increase. For microorganisms the interaction with dissolved substances and suspended sediment particles so far has hardly been investigated. We specifically tested: (1) the importance of suspended particles as an uptake route for dissolved substances; and (2) the significance of particle surface properties, i.e. surface load and mineralogy. As a model system we used an axenically cultured strain of a widespread and often abundant flagellate ('Spumella-like' flagellate strain JBM10). We tested the toxicity of cadmium (II) and mercury (II) as well as availability of dissolved organic matter (DOM) in the absence as well as in the presence of different natural clays, i.e. a kaolinite, a montmorillonite, and a mixed clay, and of artificial silicate particles of different surface charge. When applied separately the presence of the heavy metals cadmium and mercury as well as of suspended particles negatively affected the investigated flagellate but nutritive organics supported growth of the investigated flagellate. Toxic stress response comprises behavioral changes including enhanced swimming activity and stress egestion of ingested particles and was generally similar for a variety of different flagellate species. In combination with suspended particles, the respective effect of trace metals and nutritive substances decreased. Regarding the particle quality, cadmium toxicity increased with increasingly negative surface charge, i.e. increasing surface density of silanol groups (Pearson's product moment, P = 0.005). For mercury particle mineralogy still had a significant effect (P < 0

Study of Running Stability in Side-Suspended HTS-PMG Maglev Circular Line System

Science.gov (United States)

Zhou, Dajin; Zhao, Lifeng; Li, Linbo; Cui, Chenyu; Hsieh, Chang-Chun; Zhang, Yong; Guo, Jianqiang; Zhao, Yong

2017-07-01

A research on stability of the side-suspended HTS-PMG maglev circular line system is carried out through simulation experiment. The results show that the maglev vehicle will gradually get close to the track surface during acceleration under the action of centrifugal force, leading to decay of guidance force and occurrence of vertical eccentric motion. In case of linear array of YBa2Cu3O7-x (YBCO) bulks, the guidance force will be changed with the decreasing of the levitation gap. It can be suppressed through the complex arrangement of YBCO bulks. Fortunately, triangle array of YBCO bulks can effectively keep the guidance force constant and realize stable running during accelerating process of the prototype vehicle. Based on the research on stability of side-suspended maglev vehicle, a side-suspended PMG circular test track with diameter of 6.5 m and circumference of 20.4 m is successfully designed and established, enabling the prototype vehicle to run stably at up to 82.5 km/h under open atmosphere (9.6 × 104 Pa).

Low-energy electron point projection microscopy of suspended graphene, the ultimate 'microscope slide'

International Nuclear Information System (INIS)

Mutus, J Y; Livadaru, L; Urban, R; Salomons, M H; Cloutier, M; Wolkow, R A; Robinson, J T

2011-01-01

Point projection microscopy (PPM) is used to image suspended graphene by using low-energy electrons (100-205 eV). Because of the low energies used, the graphene is neither damaged nor contaminated by the electron beam for doses of the order of 10 7 electrons per nm 2 . The transparency of graphene is measured to be 74%, equivalent to electron transmission through a sheet twice as thick as the covalent radius of sp 2 -bonded carbon. Also observed is rippling in the structure of the suspended graphene, with a wavelength of approximately 26 nm. The interference of the electron beam due to diffraction off the edge of a graphene knife edge is observed and is used to calculate a virtual source size of 4.7±0.6 A for the electron emitter. It is demonstrated that graphene can serve as both the anode and the substrate in PPM, thereby avoiding distortions due to strong field gradients around nanoscale objects. Graphene can be used to image objects suspended on the sheet using PPM and, in the future, electron holography.

LOCAL ALGORITHM FOR MONITORING TOTAL SUSPENDED SEDIMENTS IN MICRO-WATERSHEDS USIN DRONES AND REMOTE SENSING APPLICATIONS. CASE STUDY: TEUSACÁ RIVER, LA CALERA, COLOMBIA

Directory of Open Access Journals (Sweden)

N. A. Sáenz

2015-08-01

Full Text Available An empirical relationship of Total Suspended Sediments (TSS concentrations and reflectance values obtained with Drones’ aerial photos and processed using remote sensing tools was set up as the main objective of this research. A local mathematic algorithm for the micro-watershed of the Teusacá River at La Calera, Colombia, was developed based on the computing of four component of bands from consumed-grade cameras obtaining from each their corresponding reflectance values from procedures for correcting digital camera imagery and using statistical analysis for study the fit and RMSE of 25 regressions. The assessment was characterized by the comparison of reflectance values and 34 in-situ data measurements concentrations between 1.6 and 33 mg L−1 taken from the superficial layer of the river in two campaigns. A large data set of empirical and referenced algorithm from literature were used to evaluate the accuracy and precision of the relationship. For estimation of TSS, a higher accuracy was achieved using the Tassan’s algorithm with the BAND X/ BANDX ratio. The correlation coefficient with R2 = X demonstrate the feasibility of use remote sensed data with consumed-grade cameras as an effective tool for a frequent monitoring and controlling of water quality parameters such as Total Suspended Solids of watersheds, these being the most vulnerable and less compliance with environmental regulations.

An experimental study on suspended sodium droplet combustion (3)

International Nuclear Information System (INIS)

Sato, Kenji

2005-03-01

As part of studies for phenomenological investigation of sodium droplet burning behavior, in our previous experimental studies for suspended single sodium droplet, behavior of ignition process and succeeding combustion, ignition delay time, and droplet temperature history had been investigated. In this study, combustion experiments of suspended sodium droplet were performed in upward dry air flow by expanding the range of free-stream velocity U of air flow into 400 cm/s with initial droplet temperature Ti=300, 350, and 400degC and initial droplet diameter 4 mm at first. Then, the combustion experiments were also performed by changing the initial droplet diameter from 2.3 to 4.4 mm with Ti=350 and 400degC and U=100 cm/s. From the experimental results, the effects of free-stream velocity, initial droplet temperature, and initial droplet diameter on the ignition/burning behavior and ignition delay time were examined. The obtained results are as follows: (1) Ignition phenomena of suspended droplet were observed for all examined experimental conditions up to 400 cm/s. The orange emission observed at the moment of ignition occurs simultaneously over whole droplet surface except the top region of it. (2) The feature of the dependence of ignition delay time on the free-stream velocity is independent of the initial droplet temperature. With the increase of the free-stream velocity, up to 300 cm/s the ignition delay time decreases with decreasing dependency, and then the dependency increases more. (3) The ignition delay time increases with the increase of initial droplet diameter. The dependency increases as the initial droplet diameter increases. The ignition delay time extrapolated toward zero diameters from the obtained results becomes to be essentially zero. (author)

A long-term survey on anthropogenic impacts to the water quality of coral reefs, southern Taiwan

International Nuclear Information System (INIS)

Meng, P.-J.; Lee, H.-J.; Wang, J.-T.; Chen, C.-C.; Lin, H.-J.; Tew, K.S.; Hsieh, W.-J.

2008-01-01

Before 2001, the ecological protection area in the Kenting National Park (KTNP), southern Taiwan, was poorly described. In this study, a set of four-year data (2001-2004) of seawater qualities at 19 sampling sites around the Nanwan Bay in the KTNP was used to explore anthropogenic impacts to ecological environment, especially coral reefs. The parameters of water quality were analyzed immediately after collection. The results showed that higher values of nutrients and suspended solids were attributed to the higher run-off around Nanwan Bay. The fluxes of nutrients and suspended solids were consistently correlated to rainfall. Hence, equations were developed to calculate nutrient fluxes and suspended solids by using only rainfall data. Our results show that suspended solids and ammonia were the dominant factors leading to the drop in coral coverage. In summary, the water quality in the intertidal zone of Nanwan Bay has been degraded and required greater attention. - Suspended solids and ammonium in discharge derived from anthropogenic activities are two main factors causing drop in coral coverage

A long-term survey on anthropogenic impacts to the water quality of coral reefs, southern Taiwan

Energy Technology Data Exchange (ETDEWEB)

Meng, P.-J. [National Museum of Marine Biology and Aquarium, Checheng, Pingtung 944, Taiwan (China); Institute of Marine Biodiversity and Evolution, National Dong Hwa University, Checheng, Pingtung 944, Taiwan (China)], E-mail: pjmeng@nmmba.gov.tw; Lee, H.-J. [Department of Marine Environmental Informatics, National Taiwan Ocean University, Keelung 20224, Taiwan (China); Wang, J.-T. [Tajen University, Pingtung 907, Taiwan (China)], E-mail: jtw@mail.tajen.edu.tw; Chen, C.-C. [Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan (China); Lin, H.-J. [Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan (China); Tew, K.S. [National Museum of Marine Biology and Aquarium, Checheng, Pingtung 944, Taiwan (China); Institute of Marine Biodiversity and Evolution, National Dong Hwa University, Checheng, Pingtung 944, Taiwan (China); Hsieh, W.-J. [National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan (China)

2008-11-15

Before 2001, the ecological protection area in the Kenting National Park (KTNP), southern Taiwan, was poorly described. In this study, a set of four-year data (2001-2004) of seawater qualities at 19 sampling sites around the Nanwan Bay in the KTNP was used to explore anthropogenic impacts to ecological environment, especially coral reefs. The parameters of water quality were analyzed immediately after collection. The results showed that higher values of nutrients and suspended solids were attributed to the higher run-off around Nanwan Bay. The fluxes of nutrients and suspended solids were consistently correlated to rainfall. Hence, equations were developed to calculate nutrient fluxes and suspended solids by using only rainfall data. Our results show that suspended solids and ammonia were the dominant factors leading to the drop in coral coverage. In summary, the water quality in the intertidal zone of Nanwan Bay has been degraded and required greater attention. - Suspended solids and ammonium in discharge derived from anthropogenic activities are two main factors causing drop in coral coverage.

Ultra-sensitive suspended atomically thin-layered black phosphorus mercury sensors.

Science.gov (United States)

Li, Peng; Zhang, Dongzhi; Jiang, Chuanxing; Zong, Xiaoqi; Cao, Yuhua

2017-12-15

The extraordinary properties of black phosphorus (BP) make it a promising candidate for next-generation transistor chemical sensors. However, BP films reported so far are supported on substrate, and substrate scattering drastically deteriorates its electrical properties. Consequentially, the potential sensing capability of intrinsic BP is highly underestimated and its sensing mechanism is masked. Additionally, the optimum sensing regime of BP remains unexplored. This article is the first demonstration of suspended BP sensor operated in subthreshold regime. BP exhibited significant enhancement of sensitivity for ultra-low-concentration mercury detection in the absence of substrate, and the sensitivity reached maximum in subthreshold regime. Without substrate scattering, the suspended BP device demonstrated 10 times lower 1/f noise which contributed to better signal-to-noise ratio. Therefore, rapid label-free trace detection of Hg 2+ was achieved with detection limit of 0.01 ppb, lower than the world health organization (WHO) tolerance level (1 ppb). The time constant for ion detection extracted was 3s. Additionally, experimental results revealed that good stability, repeatability, and selectivity were achieved. BP sensors also demonstrated the ability of detecting mercury ions in environment water samples. The underling sensing mechanism of intrinsic BP was ascribed to the carrier density variation resulted from surface charge gating effect, so suspended BP in subthreshold regime with optimum gating effect demonstrated the best sensitivity. Our results show the prominent advantages of intrinsic BP as a sensing material. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Frequency Selection for Multi-frequency Acoustic Measurement of Suspended Sediment

Science.gov (United States)

Chen, X.; HO, H.; Fu, X.

2017-12-01

Multi-frequency acoustic measurement of suspended sediment has found successful applications in marine and fluvial environments. Difficult challenges remain in regard to improving its effectiveness and efficiency when applied to high concentrations and wide size distributions in rivers. We performed a multi-frequency acoustic scattering experiment in a cylindrical tank with a suspension of natural sands. The sands range from 50 to 600 μm in diameter with a lognormal size distribution. The bulk concentration of suspended sediment varied from 1.0 to 12.0 g/L. We found that the commonly used linear relationship between the intensity of acoustic backscatter and suspended sediment concentration holds only at sufficiently low concentrations, for instance below 3.0 g/L. It fails at a critical value of concentration that depends on measurement frequency and the distance between the transducer and the target point. Instead, an exponential relationship was found to work satisfactorily throughout the entire range of concentration. The coefficient and exponent of the exponential function changed, however, with the measuring frequency and distance. Considering the increased complexity of inverting the concentration values when an exponential relationship prevails, we further analyzed the relationship between measurement error and measuring frequency. It was also found that the inversion error may be effectively controlled within 5% if the frequency is properly set. Compared with concentration, grain size was found to heavily affect the selection of optimum frequency. A regression relationship for optimum frequency versus grain size was developed based on the experimental results.

Guidelines and Procedures for Computing Time-Series Suspended-Sediment Concentrations and Loads from In-Stream Turbidity-Sensor and Streamflow Data

Science.gov (United States)

Rasmussen, Patrick P.; Gray, John R.; Glysson, G. Douglas; Ziegler, Andrew C.

2009-01-01

In-stream continuous turbidity and streamflow data, calibrated with measured suspended-sediment concentration data, can be used to compute a time series of suspended-sediment concentration and load at a stream site. Development of a simple linear (ordinary least squares) regression model for computing suspended-sediment concentrations from instantaneous turbidity data is the first step in the computation process. If the model standard percentage error (MSPE) of the simple linear regression model meets a minimum criterion, this model should be used to compute a time series of suspended-sediment concentrations. Otherwise, a multiple linear regression model using paired instantaneous turbidity and streamflow data is developed and compared to the simple regression model. If the inclusion of the streamflow variable proves to be statistically significant and the uncertainty associated with the multiple regression model results in an improvement over that for the simple linear model, the turbidity-streamflow multiple linear regression model should be used to compute a suspended-sediment concentration time series. The computed concentration time series is subsequently used with its paired streamflow time series to compute suspended-sediment loads by standard U.S. Geological Survey techniques. Once an acceptable regression model is developed, it can be used to compute suspended-sediment concentration beyond the period of record used in model development with proper ongoing collection and analysis of calibration samples. Regression models to compute suspended-sediment concentrations are generally site specific and should never be considered static, but they represent a set period in a continually dynamic system in which additional data will help verify any change in sediment load, type, and source.

A Passively-Suspended Tesla Pump Left Ventricular Assist Device

Science.gov (United States)

Izraelev, Valentin; Weiss, William J.; Fritz, Bryan; Newswanger, Raymond K.; Paterson, Eric G.; Snyder, Alan; Medvitz, Richard B.; Cysyk, Joshua; Pae, Walter E.; Hicks, Dennis; Lukic, Branka; Rosenberg, Gerson

2009-01-01

The design and initial test results of a new passively suspended Tesla type LAVD blood pump are described. CFD analysis was used in the design of the pump. Overall size of the prototype device is 50 mm in diameter and 75 mm in length. The pump rotor has a density lower than that of blood and when spinning inside the stator in blood it creates a buoyant centering force that suspends the rotor in the radial direction. The axial magnetic force between the rotor and stator restrain the rotor in the axial direction. The pump is capable of pumping up to 10 liters/min at a 70 mmHg head rise at 8000 RPM. The pump has demonstrated a normalized index of hemolysis level below .02 mg/dL for flows between 2 and 9.7 L/min. An inlet pressure sensor has also been incorporated into the inlet cannula wall and will be used for control purposes. One initial in vivo study showed an encouraging result. Further CFD modeling refinements are planned as well as endurance testing of the device. PMID:19770799

Near-Bed Monitoring of Suspended Sediment during a Major Flood Event Highlights Deficiencies in Existing Event-Loading Estimates

Directory of Open Access Journals (Sweden)

Alistair Grinham

2018-01-01

Full Text Available Rates of fluvial sediment discharge are notoriously difficult to quantify, particularly during major flood events. Measurements are typically undertaken using event stations requiring large capital investment, and the high cost tends to reduce the spatial coverage of monitoring sites. This study aimed to characterise the near-bed suspended sediment dynamics during a major flood event using a low-cost approach. Monitoring nodes consisted of a total suspended sediment (TSS logger, a single stage sampler, and a time-lapse camera for a total cost of less than US$420. Seven nodes were deployed across an elevation gradient on the stream bank of Laidley Creek, Queensland, Australia, and two of these nodes successfully characterised the near-bed suspended sediment dynamics across a major flood event. Near-bed TSS concentrations were closely related to stream flow, with the contribution of suspended bed material dominating the total suspended load during peak flows. Observed TSS concentrations were orders of magnitude higher than historical monitoring data for this site collected using the State government event station. This difference was attributed to the event station pump inlet screening the suspended bed material prior to sample collection. The ‘first flush’ phenomenon was detected and attributed to a local resuspension of muddy crusts immediately upstream of the study site. This low-cost approach will provide an important addition to the existing monitoring of fluvial sediment discharge during flood events.

On-chip photonic system using suspended p-n junction InGaN/GaN multiple quantum wells device and multiple waveguides

International Nuclear Information System (INIS)

Wang, Yongjin; Zhu, Guixia; Gao, Xumin; Yang, Yongchao; Yuan, Jialei; Shi, Zheng; Zhu, Hongbo; Cai, Wei

2016-01-01

We propose, fabricate, and characterize the on-chip integration of suspended p-n junction InGaN/GaN multiple quantum wells (MQWs) device and multiple waveguides on the same GaN-on-silicon platform. The integrated devices are fabricated via a wafer-level process and exhibit selectable functionalities for diverse applications. As the suspended p-n junction InGaN/GaN MQWs device operates under a light emitting diode (LED) mode, part of the light emission is confined and guided by the suspended waveguides. The in-plane propagation along the suspended waveguides is measured by a micro-transmittance setup. The on-chip data transmission is demonstrated for the proof-of-concept photonic integration. As the suspended p-n junction InGaN/GaN MQWs device operates under photodiode mode, the light is illuminated on the suspended waveguides with the aid of the micro-transmittance setup and, thus, coupled into the suspended waveguides. The guided light is finally sensed by the photodiode, and the induced photocurrent trace shows a distinct on/off switching performance. These experimental results indicate that the on-chip photonic integration is promising for the development of sophisticated integrated photonic circuits in the visible wavelength region.

Physical Conditions Regulate the Fungal to Bacterial Ratios of a Tropical Suspended Soil

Directory of Open Access Journals (Sweden)

Julian Donald

2017-12-01

Full Text Available As a source of ‘suspended soils’, epiphytes contribute large amounts of organic matter to the canopy of tropical rain forests. Microbes associated with epiphytes are responsible for much of the nutrient cycling taking place in rain forest canopies. However, soils suspended far above the ground in living organisms differ from soil on the forest floor, and traditional predictors of soil microbial community composition and functioning (nutrient availability and the activity of soil organisms are likely to be less important. We conducted an experiment in the rain forest biome at the Eden Project in the U.K. to explore how biotic and abiotic conditions determine microbial community composition and functioning in a suspended soil. To simulate their natural epiphytic lifestyle, bird’s nest ferns (Asplenium nidus were placed on a custom-built canopy platform suspended 8 m above the ground. Ammonium nitrate and earthworm treatments were applied to ferns in a factorial design. Extracellular enzyme activity and Phospholipid Fatty Acid (PLFA profiles were determined at zero, three and six months. We observed no significant differences in either enzyme activity or PLFA profiles between any of the treatments. Instead, we observed decreases in β-glucosidase and N-acetyl-glucosaminidase activity, and an increase in phenol oxidase activity across all treatments and controls over time. An increase in the relative abundance of fungi during the experiment meant that the microbial communities in the Eden Project ferns after six months were comparable with ferns sampled from primary tropical rain forest in Borneo.

40 CFR 421.74 - Standards of performance for new sources.

Science.gov (United States)

2010-07-01

... slag, speiss, or matte granulated Lead .000 .000 Zinc .000 .000 Total suspended solids .000 .000 pH (1.../kkg (pounds per billion pounds) of sinter production Lead .000 .000 Zinc .000 .000 Total suspended... Zinc .000 .000 Total suspended solids .000 .000 pH (1) (1) 1Within the range of 7.5 to 10.0 at all...

Prediction of suspended-sediment concentrations at selected sites in the Fountain Creek watershed, Colorado, 2008-09

Science.gov (United States)

Stogner, Sr., Robert W.; Nelson, Jonathan M.; McDonald, Richard R.; Kinzel, Paul J.; Mau, David P.

2013-01-01

In 2008, the U.S. Geological Survey (USGS), in cooperation with Pikes Peak Area Council of Governments, Colorado Water Conservation Board, Colorado Springs City Engineering, and the Lower Arkansas Valley Water Conservancy District, began a small-scale pilot study to evaluate the effectiveness of the use of a computational model of streamflow and suspended-sediment transport for predicting suspended-sediment concentrations and loads in the Fountain Creek watershed in Colorado. Increased erosion and sedimentation damage have been identified by the Fountain Creek Watershed Plan as key problems within the watershed. A recommendation in the Fountain Creek Watershed plan for management of the basin is to establish measurable criteria to determine if progress in reducing erosion and sedimentation damage is being made. The major objective of this study was to test a computational method to predict local suspended-sediment loads at two sites with different geomorphic characteristics in order to evaluate the feasibility of using such an approach to predict local suspended-sediment loads throughout the entire watershed. Detailed topographic surveys, particle-size data, and suspended-sediment samples were collected at two gaged sites: Monument Creek above Woodmen Road at Colorado Springs, Colorado (USGS gage 07103970), and Sand Creek above mouth at Colorado Springs, Colorado (USGS gage 07105600). These data were used to construct three-dimensional computational models of relatively short channel reaches at each site. The streamflow component of these models predicted a spatially distributed field of water-surface elevation, water velocity, and bed shear stress for a range of stream discharges. Using the model predictions, along with measured particle sizes, the sediment-transport component of the model predicted the suspended-sediment concentration throughout the reach of interest. These computed concentrations were used with predicted flow patterns and channel morphology to

Experimental realization of suspended atomic chains composed of different atomic species

International Nuclear Information System (INIS)

Bettini, Jefferson; Ugarte, Daniel; Sato, Fernando; Galvao, Douglas Soares; Coura, Pablo Zimmerman; Dantas, Socrates de Oliveira

2006-01-01

We report high resolution transmission electron microscopy (HRTEM) and molecular dynamics results of the first experimental test of suspended atomic chains composed of different atomic species formed from spontaneous stretching of metallic nanowires. (author)

Water-quality conditions and suspended-sediment transport in the Wilson and Trask Rivers, northwestern Oregon, water years 2012–14

Science.gov (United States)

Sobieszczyk, Steven; Bragg, Heather M.; Uhrich, Mark A.

2015-07-28

In October 2011, the U.S. Geological Survey began investigating and monitoring water-quality conditions and suspended-sediment transport in the Wilson and Trask Rivers, northwestern Oregon. Water temperature, specific conductance, turbidity, and dissolved oxygen were measured every 15–30 minutes in both streams using real-time instream water-quality monitors. In conjunction with the monitoring effort, suspended-sediment samples were collected and analyzed to model the amount of suspended sediment being transported by each river. Over the course of the 3-year study, which ended in September 2014, nearly 600,000 tons (t) of suspended-sediment material entered Tillamook Bay from these two tributaries. 

A direct simulation method for flows with suspended paramagnetic particles

NARCIS (Netherlands)

Kang, T.G.; Hulsen, M.A.; Toonder, den J.M.J.; Anderson, P.D.; Meijer, H.E.H.

2008-01-01

A direct numerical simulation method based on the Maxwell stress tensor and a fictitious domain method has been developed to solve flows with suspended paramagnetic particles. The numerical scheme enables us to take into account both hydrodynamic and magnetic interactions between particles in a

2 CFR 801.1010 - Suspending official (Department of Veterans Affairs supplement to government-wide definition at 2...

Science.gov (United States)

2010-01-01

... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Suspending official (Department of Veterans Affairs supplement to government-wide definition at 2 CFR 180.1010). 801.1010 Section 801.1010 Grants and... DEBARMENT AND SUSPENSION Definitions § 801.1010 Suspending official (Department of Veterans Affairs...

Performance of suspended and attached growth MBR systems in treating high strength synthetic wastewater.

Science.gov (United States)

Jamal Khan, S; Ilyas, Shazia; Javid, Sadaf; Visvanathan, C; Jegatheesan, V

2011-05-01

The performance of laboratory-scale attached growth (AG) and suspended growth (SG) membrane bioreactors (MBRs) was evaluated in treating synthetic wastewater simulating high strength domestic wastewater. This study investigated the influence of sponge suspended carriers in AG-MBR system, occupying 15% reactor volume, on the removal of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP), and compared it to that of SG-MBR. Results showed that the removal efficiencies of COD, TN and TP in AG-MBR were 98%, 89% and 58%, respectively as compared to 98%, 74% and 38%, respectively in SG-MBR. Improved TN removal in AG-MBR systems was primarily based on simultaneous nitrification and denitrification (SND) process. These results infer that the presence of small bio-particles having higher microbial activity and the growth of complex biomass captured within the suspended sponge carriers resulted in improved TN and TP removal in AG-MBR. Copyright © 2010 Elsevier Ltd. All rights reserved.

Determining Time Variation of Cable Tension Forces in Suspended Bridges Using Time-Frequency Analysis

Directory of Open Access Journals (Sweden)

Gannon Stromquist-LeVoir

2018-01-01

Full Text Available A feasibility study was conducted to develop a novel method to determine the temporal changes of tensile forces in bridge suspender cables using time-frequency analysis of ambient vibration measurements. An analytical model of the suspender cables was developed to evaluate the power spectral density (PSD function of a cable with consideration of cable flexural stiffness. Discrete-time, short-time Fourier transform (STFT was utilized to analyze the recorded acceleration histories in both time and frequency domains. A mathematical convolution of the analytical PSD function and time-frequency data was completed to evaluate changes in cable tension force over time. The method was implemented using acceleration measurements collected from an in-service steel arch bridge with a suspended deck to calculate the temporal variation in cable forces from the vibration measurements. The observations served as proof of concept that the proposed method may be used for cable fatigue life calculations and bridge weigh-in-motion studies.

Gas suspension flows of a moderately dense binary mixture of solid particles in vertical tubes

Energy Technology Data Exchange (ETDEWEB)

Zamankhan, P.; Huotari, J. [VTT Energy, Jyvaeskylae (Finland). Combustion and Conversion Lab.

1996-12-01

The turbulent, steady, fully-developed flow of a moderately dense (solid volume faction >>0.001) binary mixture of spherical particles in a gaseous carrier is investigated for the case of flow in a vertical riser. The suspended particles are considered to be in turbulent motion, driven by random aerodynamic forces acting between the particle and the gaseous carrier as well as particle-particle interactive forces. A model is constructed based on the combination of the time-averaged after volume-averaged conservation equations of mass, momentum and mechanical energy of the gas phase in the continuum theory and the corresponding equations for the solid particles obtained using the recently developed Enskog theory for dense multi-component mixtures of slightly inelastic spherical particles. The model properly takes into account the contributions of particle-particle collisions, as well as the fluid-dynamic fluctuating forces on individual particles. To demonstrate the validity of this approach, the fully-developed steady-state mean velocity and concentration distributions of a moderately dense binary mixture of solid particles in a turbulent vertical flow calculated by the present model are compared with available experimental measurements. The results provide a qualitative description of the experimentally observed motion of coarse particles in a fast bed of fine solids. (author)

Some properties of suspended sediment absorbed cations in turbid freshwaters of South Africa

International Nuclear Information System (INIS)

Grobbelaar, J.U.; Stegmann, P.; Keulder, P.C.

1980-01-01

Large quantities of suspended sediments are common in many of South Africa's freshwaters. Temporal and spatial variations in the amounts of cations adsorbed were recorded. The adsorption appears to be dependent on valency, because greater quantities of the higher valencies are adsorbed. Ca++ dominated the adsorbed cations and Mg++ the dissolved fraction. Water originating from the Beaufort Series contained high sodium concentrations. Fe++ dominated the adsorbed minor cations. Large quantities of sediments transported by rivers enter impoundments. The adsorbed ions transported in this way are influenced by the type of suspended sediment and form a significant part of the total input of ions

LAGRANGIAN MODELING OF A SUSPENDED-SEDIMENT PULSE.

Science.gov (United States)

Schoellhamer, David H.

1987-01-01

The one-dimensional Lagrangian Transport Model (LTM) has been applied in a quasi two-dimensional manner to simulate the transport of a slug injection of microbeads in steady experimental flows. A stationary bed segment was positioned below each parcel location to simulate temporary storage of beads on the bottom of the flume. Only one degree of freedom was available for all three bead simulations. The results show the versatility of the LTM and the ability of the LTM to accurately simulate transport of fine suspended sediment.

Suspended sediment fluxes in a tropical estuary, west coast of India

Digital Repository Service at National Institute of Oceanography (India)

AnilKumar, N.; DineshKumar, P.K.; Srinivas, K.

Annual transport processes of suspended sediments in Beypore estuary - a tropical estuary along the south west coast of India - were investigated based on time series measurements within the system. It's observed that the sediment transport...

Suspended sediment transport and shoaling in the Munambam fishery harbour, Kerala

Digital Repository Service at National Institute of Oceanography (India)

Revichandran, C.; Abraham, P.; Josanto, V.; Sankaranarayanan, V.N.

Results of the monthly synoptic field observations of vertical profiles of suspended sediment concentration, current velocity and salinity carried out in the Azhicode Estuary are presented with a view to understand the shoaling and siltation...

Experimental study on Kd of 137Cs at varying suspended load conditions

International Nuclear Information System (INIS)

Jaison, T.J.; Jain, Abhishek; Patra, A.K.; Ravi, P.M.; Tripathi, R.M.

2018-01-01

137 Cs is one of the radionuclide likely to be released through liquid effluents from a nuclear facility. It is soluble in water, but its mobility in aquatic environments is highly retarded by its strong interaction with suspended sediment. The 137 Cs + sorption by suspended load, especially in the subtropics and tropics are not fully understood. Besides, according to IAEA document in emergency situation 137 Cs and 131 I being marker radionuclides, are easier to identify and representative of all the other radionuclides present. Hence a laboratory study is carried out on sorption of 137 Cs with varying silt load, using the upstream lake water and sediments to estimate site specific distribution coefficient (K d )

Pre-aged soil organic carbon as a major component of the Yellow River suspended load: Regional significance and global relevance

Science.gov (United States)

Tao, Shuqin; Eglinton, Timothy I.; Montluçon, Daniel B.; McIntyre, Cameron; Zhao, Meixun

2015-03-01

Large rivers connect the continents and the oceans, and corresponding material fluxes have a global impact on marine biogeochemistry. The Yellow River transports vast quantities of suspended sediments to the ocean, yet the nature of the particulate organic carbon (POC) carried by this system is not well known. The focus of this study is to characterize the sources, composition and age of suspended POC collected near the terminus of this river system, focusing on the abundance and carbon isotopic composition (13C and 14C) of specific biomarkers. The concentrations of vascular plant wax lipids (long-chain (≥C24) n-alkanes, n-fatty acids) and POC co-varied with total suspended solid (TSS) concentrations, indicating that both were controlled by the overall terrestrial sediment flux. POC exhibited relatively uniform δ13C values (-23.8 to -24.2‰), and old radiocarbon ages (4000-4640 yr). However, different biomarkers exhibited a wide range of 14C ages. Short-chain (C16, C18) fatty acid 14C ages were variable but generally the youngest organic components (from 502 yr to modern), suggesting they reflect recently biosynthesized material. Lignin phenol 14C ages were also variable and relatively young (1070 yr to modern), suggesting rapid export of carbon from terrestrial primary production. In contrast, long-chain plant wax lipids display relatively uniform and significantly older 14C ages (1500-1800 yr), likely reflecting inputs of pre-aged, mineral-associated soil OC from the Yellow River drainage basin. Even-carbon-numbered n-alkanes yielded the oldest 14C ages (up to 26 000 yr), revealing the presence of fossil (petrogenic) OC. Two isotopic mass balance approaches were explored to quantitively apportion different OC sources in Yellow River suspended sediments. Results indicate that the dominant component of POC (53-57%) is substantially pre-aged (1510-1770 yr), and likely sourced from the extensive loess-paleosol deposits outcropping within the drainage basin. Of

Metabolism of branched-chain amino acids in leg muscles from tail-cast suspended intact and adrenalectomized rats

Science.gov (United States)

Jaspers, Stephen R.; Henriksen, Erik; Jacob, Stephan; Tischler, Marc E.

1989-01-01

The effects of muscle unloading, adrenalectomy, and cortisol treatment on the metabolism of branched-chain amino acids in the soleus and extensor digitorum longus of tail-cast suspended rats were investigated using C-14-labeled lucine, isoleucine, and valine in incubation studies. It was found that, compared to not suspended controls, the degradation of branched-chain amino acids in hind limb muscles was accelerated in tail-cast suspended rats. Adrenalectomy was found to abolish the aminotransferase flux and to diminish the dehydrogenase flux in the soleus. The data also suggest that cortisol treatment increases the rate of metabolism of branched-chain amino acids at the dehydrogenase step.

Sources of suspended-sediment flux in streams of the chesapeake bay watershed: A regional application of the sparrow model

Science.gov (United States)

Brakebill, J.W.; Ator, S.W.; Schwarz, G.E.

2010-01-01

We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban development generates on average the greatest amount of suspended sediment per unit area (3,928 Mg/km2/year), although agriculture is much more widespread and is the greatest overall source of suspended sediment (57 Mg/km2/year). Factors affecting sediment transport from uplands to streams include mean basin slope, reservoirs, physiography, and soil permeability. On average, 59% of upland suspended sediment generated is temporarily stored along large rivers draining the Coastal Plain or in reservoirs throughout the watershed. Applying erosion and sediment controls from agriculture and urban development in areas of the northern Piedmont close to the upper Bay, where the combined effects of watershed characteristics on sediment transport have the greatest influence may be most helpful in mitigating sedimentation in the bay and its tributaries. Stream restoration efforts addressing floodplain and bank stabilization and incision may be more effective in smaller, headwater streams outside of the Coastal Plain. ?? 2010 American Water Resources Association. No claim to original U.S. government works.

Modelling the transport of suspended particulate matter by the Rhone River plume (France). Implications for pollutant dispersion

International Nuclear Information System (INIS)

Perianez, R.

2005-01-01

A model to simulate the transport of suspended particulate matter by the Rhone River plume has been developed. The model solves the 3D hydrodynamic equations, including baroclinic terms and a 1-equation turbulence model, and the suspended matter equations including advection/diffusion of particles, settling and deposition. Four particle classes are considered simultaneously according to observations in the Rhone. Computed currents, salinity and particle distributions are, in general, in good agreement with observations or previous calculations. The model also provides sedimentation rates and the distribution of different particle classes over the sea bed. It has been found that high sedimentation rates close to the river mouth are due to coarse particles that sink rapidly. Computed sedimentation rates are also similar to those derived from observations. The model has been applied to simulate the transport of radionuclides by the plume, since suspended matter is the main vector for them. The radionuclide transport model, previously described and validated, includes exchanges of radionuclides between water, suspended matter and bottom sediment described in terms of kinetic rates. A new feature is the explicit inclusion of the dependence of kinetic rates upon salinity. The model has been applied to 137 Cs and 239,240 Pu. Results are, in general, in good agreement with observations. - A model has been developed to simulate transport of suspended particulate matter in the Rhone River plume

Compilation, quality control, analysis, and summary of discrete suspended-sediment and ancillary data in the United States, 1901-2010

Science.gov (United States)

Lee, Casey J.; Glysson, G. Douglas

2013-01-01

Human-induced and natural changes to the transport of sediment and sediment-associated constituents can degrade aquatic ecosystems and limit human uses of streams and rivers. The lack of a dedicated, easily accessible, quality-controlled database of sediment and ancillary data has made it difficult to identify sediment-related water-quality impairments and has limited understanding of how human actions affect suspended-sediment concentrations and transport. The purpose of this report is to describe the creation of a quality-controlled U.S. Geological Survey suspended-sediment database, provide guidance for its use, and summarize characteristics of suspended-sediment data through 2010. The database is provided as an online application at http://cida.usgs.gov/sediment to allow users to view, filter, and retrieve available suspended-sediment and ancillary data. A data recovery, filtration, and quality-control process was performed to expand the availability, representativeness, and utility of existing suspended-sediment data collected by the U.S. Geological Survey in the United States before January 1, 2011. Information on streamflow condition, sediment grain size, and upstream landscape condition were matched to sediment data and sediment-sampling sites to place data in context with factors that may influence sediment transport. Suspended-sediment and selected ancillary data are presented from across the United States with respect to time, streamflow, and landscape condition. Examples of potential uses of this database for identifying sediment-related impairments, assessing trends, and designing new data collection activities are provided. This report and database can support local and national-level decision making, project planning, and data mining activities related to the transport of suspended-sediment and sediment-associated constituents.

Chemically pretreating slaughterhouse solid waste to increase the efficiency of anaerobic digestion.

Science.gov (United States)

Flores-Juarez, Cyntia R; Rodríguez-García, Adrián; Cárdenas-Mijangos, Jesús; Montoya-Herrera, Leticia; Godinez Mora-Tovar, Luis A; Bustos-Bustos, Erika; Rodríguez-Valadez, Francisco; Manríquez-Rocha, Juan

2014-10-01

The combined effect of temperature and pretreatment of the substrate on the anaerobic treatment of the organic fraction of slaughterhouse solid waste was studied. The goal of the study was to evaluate the effect of pretreating the waste on the efficiency of anaerobic digestion. The effect was analyzed at two temperature ranges (the psychrophilic and the mesophilic ranges), in order to evaluate the effect of temperature on the performance of the anaerobic digestion process for this residue. The experiments were performed in 6 L batch reactors for 30 days. Two temperature ranges were studied: the psychrophilic range (at room temperature, 18°C average) and the mesophilic range (at 37°C). The waste was pretreated with NaOH before the anaerobic treatment. The result of pretreating with NaOH was a 194% increase in the soluble chemical oxygen demand (COD) with a dose of 0.6 g NaOH per g of volatile suspended solids (VSS). In addition, the soluble chemical oxygen demand/total chemical oxygen demand ratio (sCOD/tCOD) increased from 0.31 to 0.7. For the anaerobic treatment, better results were observed in the mesophilic range, achieving 70.7%, 47% and 47.2% removal efficiencies for tCOD, total solids (TS), and volatile solids (VS), respectively. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

High gradient magnetic filters for boiler water treatment

International Nuclear Information System (INIS)

Harland, J.R.; Nichols, R.M.

1977-01-01

Heavy metal oxide suspended solids in those steam condensates recycled to the boilers produce buildup within the boiler tubes which can lead to unequal and reduced heat transfer efficiency, and indirectly, to boiler tube failures. Recommended reductions in such suspended solids in feedwater to the economizers of modern high pressure boilers to levels of under 10 ppb have been published. The industrially-available SALA-HGMF magnetic filter has achieved these desired suspended solids levels in treating steam condensates. The high gradient magnetic filter has been shown in pilot tests to achieve and even exceed the recommended low level suspended solids in a practical and efficient industrial system. Such electromagnetic filters, when combined with good system chemistry, have achieved low single number parts per billion levels of several heavy metals with very high single-pass efficiencies

Physically based method for measuring suspended-sediment concentration and grain size using multi-frequency arrays of acoustic-doppler profilers

Science.gov (United States)

Topping, David J.; Wright, Scott A.; Griffiths, Ronald; Dean, David

2014-01-01

As the result of a 12-year program of sediment-transport research and field testing on the Colorado River (6 stations in UT and AZ), Yampa River (2 stations in CO), Little Snake River (1 station in CO), Green River (1 station in CO and 2 stations in UT), and Rio Grande (2 stations in TX), we have developed a physically based method for measuring suspended-sediment concentration and grain size at 15-minute intervals using multifrequency arrays of acoustic-Doppler profilers. This multi-frequency method is able to achieve much higher accuracies than single-frequency acoustic methods because it allows removal of the influence of changes in grain size on acoustic backscatter. The method proceeds as follows. (1) Acoustic attenuation at each frequency is related to the concentration of silt and clay with a known grain-size distribution in a river cross section using physical samples and theory. (2) The combination of acoustic backscatter and attenuation at each frequency is uniquely related to the concentration of sand (with a known reference grain-size distribution) and the concentration of silt and clay (with a known reference grain-size distribution) in a river cross section using physical samples and theory. (3) Comparison of the suspended-sand concentrations measured at each frequency using this approach then allows theory-based calculation of the median grain size of the suspended sand and final correction of the suspended-sand concentration to compensate for the influence of changing grain size on backscatter. Although this method of measuring suspended-sediment concentration is somewhat less accurate than using conventional samplers in either the EDI or EWI methods, it is much more accurate than estimating suspended-sediment concentrations using calibrated pump measurements or single-frequency acoustics. Though the EDI and EWI methods provide the most accurate measurements of suspended-sediment concentration, these measurements are labor-intensive, expensive, and

Urban Social Assistance in China: Transnational Diffusion and National Interpretation

OpenAIRE

Liu, Tao; Sun, Li

2016-01-01

In 1999 the State Council of the People’s Republic of China (PRC) introduced the Regulation on the Minimum Living Standard Scheme (MLSS, or dibao) for urban residents in China. Policy learning from different parts of the world significantly shaped the formation and expansion of the MLSS, and Chinese social policy researchers have drawn conclusions about the experiences of these multiple regions. Through expert interviews, we discovered that the Chinese social assistance scheme has been influe...

Removal of endocrine disruptors and non-steroidal anti-inflammatory drugs through wastewater chlorination: the effect of pH, total suspended solids and humic acids and identification of degradation by-products.

Science.gov (United States)

Noutsopoulos, Constantinos; Koumaki, Elena; Mamais, Daniel; Nika, Maria-Christina; Bletsou, Anna A; Thomaidis, Nikolaos S

2015-01-01

Endocrine disrupting chemicals (EDCs) and non-steroidal anti-inflammatory drugs (NSAIDs) are two groups of emerging pollutants the significance of which rests on their persistent detection in the aquatic environment and their possible adverse effects. Wastewater treatment plants are one of the major ways for transporting such chemicals in the aquatic environment. Chlorination is usually the last stage of treatment before wastewater being disposed to the aquatic environment. This work focuses on the evaluation of the effect of chlorine dose and specific wastewater characteristics (pH, total suspended solids and humic acids) on the removal of target EDCs and NSAIDs through chlorination. Another objective of this study is the identification of chlorination by-products of specific EDCs and NSAIDs and their dependence on contact time. Based on the results it is concluded that the effect of chlorine dose and humic acids concentration on the degradation of target compounds during chlorination is minimal. On the contrary, pH is a critical parameter which highly affects process performance. Moreover, it is concluded that not only the free available chlorine species, but also the properties of EDCs and NSAIDs under different pH conditions can affect chlorination process performance. The effect of TSS on the degradation of the target compounds during chlorination is more profound for chemicals with high Kow values and therefore higher affinity to partition to the particulate phase (i.e. nonylphenols, triclosan). Several degradation by-products were identified through chlorination of nonylphenol, bisphenol A and diclofenac. The dependence of these by-products on chlorination contact time is also demonstrated. Copyright © 2014 Elsevier Ltd. All rights reserved.

Suspended-sediment transport from the Green-Duwamish River to the Lower Duwamish Waterway, Seattle, Washington, 2013–17

Science.gov (United States)

Senter, Craig A.; Conn, Kathleen E.; Black, Robert W.; Peterson, Norman; Vanderpool-Kimura, Ann M.; Foreman, James R.

2018-02-28

The Green-Duwamish River transports watershed-derived sediment to the Lower Duwamish Waterway Superfund site near Seattle, Washington. Understanding the amount of sediment transported by the river is essential to the bed sediment cleanup process. Turbidity, discharge, suspended-sediment concentration (SSC), and particle-size data were collected by the U.S. Geological Survey (USGS) from February 2013 to January 2017 at the Duwamish River, Washington, within the tidal influence at river kilometer 16.7 (USGS streamgage 12113390; Duwamish River at Golf Course at Tukwila, WA). This report quantifies the timing and magnitude of suspended-sediment transported in the Duwamish River. Regression models were developed between SSC and turbidity and SSC and discharge to estimate 15- minute SSC. Suspended-sediment loads were calculated from the computed SSC and time-series discharge data for every 15-minute interval during the study period. The 2014–16 average annual suspended-sediment load computed was 117,246 tons (106,364 metric tons), of which 73.5 percent or (86,191 tons; 78,191 metric tons) was fine particle (less than 0.0625 millimeter in diameter) suspended sediment. The seasonality of this site is apparent when you divide the year into "wet" (October 16– April 15) and "dry" (April 16–October 15) seasons. Most (97 percent) of the annual suspended sediment was transported during the wet season, when brief periods of intense precipitation from storms, large releases from the Howard Hanson Dam, or a combination of both were much more frequent.

Optimization and development of analytical methods for the determination of new brominated flame retardants and polybrominated diphenyl ethers in sediments and suspended particulate matter

Energy Technology Data Exchange (ETDEWEB)

Lopez, P. [VU University Amsterdam, Institute for Environmental Studies (IVM), Amsterdam (Netherlands); Institute for Reference Materials and Measurements, European Commission, Joint Research Centre, Retieseweg 111, 2440, Geel (Belgium); Brandsma, S.A.; Leonards, P.E.G.; Boer, J. de [VU University Amsterdam, Institute for Environmental Studies (IVM), Amsterdam (Netherlands)

2011-05-15

With more stringent legislation on brominated flame retardants, it is expected that increasing amounts of substitutes would replace polybrominated diphenylethers (PBDEs). Therefore, the development and optimization of analytical methodologies that allow their identification and quantification are of paramount relevance. This work describes the optimization of an analytical procedure to determine pentabromochlorocyclohexane, tetrabromo-o-chlorotoluene, 2,3,5,6-tetrabromo-p-xylene, tetrabromophthalic anhydride, 2,3,4,5,6-pentabromotoluene, tris(2,3-dibromopropyl)phosphate, decabromodiphenylethane and 1,2-bis(2,4,6-tribromophenoxy)ethane together with PBDEs in sediments and in suspended particulate matter. This method comprises a pressurized liquid extraction followed by three cleanup steps (gel permeation chromatography and solid phase extraction on Oasis trademark HLB and on silica cartridges). Gas chromatography-mass spectrometry, using electron capture negative chemical ionization, is used for the final analysis. The proposed method provides recoveries >85%. The method was applied to sediment and suspended particulate matter samples from different locations in the Western Scheldt estuary (the Netherlands). To the best of our knowledge, this is the first time that the occurrence of the additive flame retardants 2,3,5,6-tetrabromo-p-xylene, 3,4,5,6-tetrabromo-o-chlorotoluene and 2,3,4,5,6-pentabromochlorocyclohexane is reported in the literature. The concentrations of these new flame retardants ranged from 0.05 to 0.30 {mu}g/kg dry weight. (orig.)

Novel Resuscitation From Lethal Hemorrhage Suspended Animation for Delayed Resuscitation, Year 7

National Research Council Canada - National Science Library

Kochanek, Patrick

2004-01-01

...). We have conceived and documented the concept of "suspended animation (SA) for delayed resuscitation" using a hypothermic saline flush into the aorta after rapid (over 5 min) exsanguination (Ex...

Cahn-Hilliard modeling of particles suspended in two-phase flows

NARCIS (Netherlands)

Choi, Y.J.; Anderson, P.D.

2012-01-01

In this paper, we present a model for the dynamics of particles suspended in two-phase flows by coupling the CahnHilliard theory with the extended finite element method (XFEM). In the CahnHilliard model the interface is considered to have a small but finite thickness, which circumvents explicit

20 CFR 901.30 - Authority to suspend or terminate enrollment.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Authority to suspend or terminate enrollment. 901.30 Section 901.30 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT OF ACTUARIES REGULATIONS... the enrollment of an enrolled actuary if the Joint Board finds that such enrolled actuary (a) Has...

Complete Evaluation of Suspended Air Particles and Their Composition in the Central Area of Yazd City

Directory of Open Access Journals (Sweden)

M Younesian

2009-01-01

Full Text Available Introduction: Air pollution is one of the problems of the recent century caused by vehicles, industries and other urban activities. The City of Yazd faces air pollution due to its high population, vehicular traffic and industrial places around the city. One of the important parameters of air pollution is suspended air particles that have harmful effects on the health of people, plants and objects. Methods: This research has been carried out by first determining a station in the central area of the city (Shahid Beheshti Square of Yazd. The suspended particles were measured during a five-month period from March to July, 2006. A high volume sampler was used for measuring Total Suspended Particles (TSP. The amount of lead content of TSP was measured in samples by using atomic absorption method. In the next stage, the percentage of organic and inorganic particles in the TSP of all samples was measured by using gravimetric methods and by burning in the oven. Results: The results of this study showed that amount of suspended particles in the city of Yazd is higher than national standard and the general mean average of the suspended particles of air in five months was 233 micrograms per cubic meter. The average concentration of suspended air particles from end of March to August during the five month period was 118, 193, 231, 267and 333, respectively. The average concentration of lead was 0.04 microgram per cubic meter and amount of organic and inorganic particles in TSP was 25.31% and 74.68%, respectively. Conclusion: With respect to the results, the minimum amount of TSP concentration was in March. This could be due to reduction in trading and industrial activities and New Year vacations. In addition, the average monthly TSP increased from March to July; the cause of which could be relative decrease in humidity and increase in temperature. The amount of lead in samples was much less than standard, which could be due to omission of lead from petrol

Experimental study on kinetics oil oil-suspended particulate matter aggregation

International Nuclear Information System (INIS)

Sun, J.; Environment Canada, Ottawa, ON; Khelifa, A.; Wang, Z.; Brown, C.; Fieldhouse, B.; Yang, C.; Zheng, X.; Wong, S.; So, L.C.

2009-01-01