Integrated pretreatment and desalination by electrocoagulation (EC)-ion concentration polarization (ICP) hybrid.

PubMed

Choi, Siwon; Kim, Bumjoo; Han, Jongyoon

2017-06-13

Conventional water treatment process is composed of multiple stages, including desalination (salt removal) and pre/post-treatment of desalination to remove particles, chemicals, and other potential foulants for desalination. In this work, we developed a microfluidic proof-of-concept for a single device water treatment system, which removes both salt ions and non-salt contaminants. Our system combines electrocoagulation (EC), a versatile contaminant removal process, and ion concentration polarization (ICP) desalination, which is an electromembrane desalination process. We demonstrated a continuous EC-ICP operation that removed >95% of suspended solids and reduced the salinity from brackish range (20 mM NaCl) to a potable level (<8.6 mM NaCl). We also demonstrated that our system is flexible in terms of the type and concentration of contaminants it can handle. Combining two different electrochemical processes into a single system, we can reduce unnecessary voltage drop by having a shared anode, and achieve both seamless integration and energy efficient operation. Our system will find applications as a small-scale water treatment system, if properly scaled up in the future.

Saline solutions: the quest for fresh water.

PubMed Central

Reuther, C G

2000-01-01

Despite steady advances in the technology, desalination remains one of the most expensive ways to produce potable water. But as water scarcity forces communities to find new sources of drinking water, scientists are developing innovations that may soon make desalination a reasonable option for many more communities. The newest approach to desalination is membrane systems, which include reverse osmosis and electrodialysis systems. Current research seeks to make these systems more effective and less likely to produce environmentally hazardous by-products. Many facilities use traditional distillation to desalinate water, and efforts are being made to combine membranes and distillation for more efficient systems. PMID:10656867

Volume 1: Survey of Available Information in Support of the Energy-Water Bandwidth Study of Desalination Systems

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

Rao, Prakash; Aghajanzadeh, Arian; Sheaffer, Paul

The U.S. Department of Energy (DOE) has set a goal to reduce the cost of seawater desalination systems to $0.50/ cubic meter (m 3) through the development of technology pathways to reduce energy, capital, operating, soft, and system integration costs.1 In support of this goal and to evaluate the technology pathways to lower the energy and carbon intensity of desalination while also reducing the total water cost, DOE is undertaking a comprehensive study of the energy consumption and carbon dioxide (CO 2) emissions for desalination technologies and systems. This study is being undertaken in two phases. Phase 1, Survey ofmore » Available Information in Support of the Energy-Water Bandwidth Study of Desalination Systems, collected the background information that will underpin Phase 2, the Energy Water Bandwidth Study for Desalination Systems. This report (Volume 1) summarizes the results from Phase 1. The results from Phase 2 will be summarized in Volume 2: Energy Water Bandwidth Study for Desalination Systems (Volume 2). The analysis effort for Phase 2 will utilize similar methods as other industry-specific Energy Bandwidth Studies developed by DOE,2 which has provided a framework to evaluate and compare energy savings potentials within and across manufacturing sectors at the macroscale. Volume 2 will assess the current state of desalination energy intensity and reduction potential through the use of advanced and emerging technologies. For the purpose of both phases of study, energy intensity is defined as the amount of energy required per unit of product water output (for example, kilowatt-hours per cubic meter of water produced). These studies will expand the scope of previous sectorial bandwidth studies by also evaluating CO 2 intensity and reduction opportunities and informing a techno-economic analysis of desalination systems. Volume 2 is expected to be completed in 2017.« less

Future Energy Benchmark for Desalination: is it Better to have a Power (electricity) Plant with ro or Med/msf?

NASA Astrophysics Data System (ADS)

Shahzad, Muhammad Wakil; Ng, Kim Choon; Thu, Kyaw

2016-06-01

Power and desalination cogeneration plants are common in many water scared courtiers. Designers and planners for cogeneration face tough challenges in deciding the options:- Is it better to operate a power plant (PP) with the reverse osmosis (i.e., PP+RO) or the thermally-driven multi-effect distillation/multi-stage flashed (PP+MED/MSF) methods. From literature, the RO methods are known to be energy efficient whilst the MED/MSF are known to have excellent thermodynamic synergies as only low pressure and temperature steam are used. Not with-standing the challenges of severe feed seawater of the Gulf, such as the frequent harmful algae blooms (HABs) and high silt contents, this presentation presents a quantitative analyses using the exergy and energetic approaches in evaluating the performances of a real cogeneration plant that was recently proposed in the eastern part of Saudi Arabia. We demonstrate that the process choice of PP+RO versus PP+MED depends on the inherent efficiencies of individual process method which is closely related to innovative process design. In this connection, a method of primary fuel cost apportionment for a co-generation plant with a MED desalination is presented. We show that an energy approach, that captures the quality of expanding steam, is a better method over the conventional work output (energetic) and the energy method seems to be over-penalizing a thermally-driven MED by as much as 22% in the operating cost of water.

Significance, evolution and recent advances in adsorption technology, materials and processes for desalination, water softening and salt removal.

PubMed

Alaei Shahmirzadi, Mohammad Amin; Hosseini, Seyed Saeid; Luo, Jianquan; Ortiz, Inmaculada

2018-06-01

Desalination and softening of sea, brackish, and ground water are becoming increasingly important solutions to overcome water shortage challenges. Various technologies have been developed for salt removal from water resources including multi-stage flash, multi-effect distillation, ion exchange, reverse osmosis, nanofiltration, electrodialysis, as well as adsorption. Recently, removal of solutes by adsorption onto selective adsorbents has shown promising perspectives. Different types of adsorbents such as zeolites, carbon nanotubes (CNTs), activated carbons, graphenes, magnetic adsorbents, and low-cost adsorbents (natural materials, industrial by-products and wastes, bio-sorbents, and biopolymer) have been synthesized and examined for salt removal from aqueous solutions. It is obvious from literature that the existing adsorbents have good potentials for desalination and water softening. Besides, nano-adsorbents have desirable surface area and adsorption capacity, though are not found at economically viable prices and still have challenges in recovery and reuse. On the other hand, natural and modified adsorbents seem to be efficient alternatives for this application compared to other types of adsorbents due to their availability and low cost. Some novel adsorbents are also emerging. Generally, there are a few issues such as low selectivity and adsorption capacity, process efficiency, complexity in preparation or synthesis, and problems associated to recovery and reuse that require considerable improvements in research and process development. Moreover, large-scale applications of sorbents and their practical utility need to be evaluated for possible commercialization and scale up. Copyright © 2018 Elsevier Ltd. All rights reserved.

Using Solar Energy to Desalinate Water.

ERIC Educational Resources Information Center

Tabor, Harry Z.

1978-01-01

Material presented is adapted from Desalination with Solar Energy, a paper presented before the International Symposium on Energy Sources and Development, held in Spain in 1977. Desalination systems energized by the sun, conditions governing their efficiency, and their costs are discussed. (HM)

Effect of the scale inhibitor on ion content in reverse osmosis system for seawater desalination

NASA Astrophysics Data System (ADS)

Gao, Yuhua; Liu, Zhenfa; Zhang, Lihui; Li, Haihua

2017-09-01

A scale inhibitor was synthesized from polysuccinimide with 2-aminoethanesulfonic acid and aspartic acid. The effect of scale inhibitor on ion content in reverse osmosis system for seawater desalination was studied. The results showed that the ion content of permeate water is lower with the scale inhibitor added in RO system for seawater desalination than without scale inhibitor. On the contrary, the ion content of concentrate water is higher when with scale inhibitor in RO system.

A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results.

PubMed

Kim, Young-Deuk; Thu, Kyaw; Ng, Kim Choon; Amy, Gary L; Ghaffour, Noreddine

2016-09-01

In this paper, a hybrid desalination system consisting of vacuum membrane distillation (VMD) and adsorption desalination (AD) units, designated as VMD-AD cycle, is proposed. The synergetic integration of the VMD and AD is demonstrated where a useful effect of the AD cycle is channelled to boost the operation of the VMD process, namely the low vacuum environment to maintain the high pressure gradient across the microporous hydrophobic membrane. A solar-assisted multi-stage VMD-AD hybrid desalination system with temperature modulating unit is first designed, and its performance is then examined with a mathematical model of each component in the system and compared with the VMD-only system with temperature modulating and heat recovery units. The total water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150 m(2) of evacuated-tube collectors and 10 m(3) seawater storage tanks, both annual collector efficiency and solar fraction are close to 60%. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Plan to Develop a Red Tide Warning System for Seawater Desalination Process Management

NASA Astrophysics Data System (ADS)

Kim, Tae Woo; Yun, Hong Sik

2017-04-01

The holt of the seawater desalination process for fifty five days due to the eight-month long red tide in 2008 in the Persian Gulf, the Middle East, had lost about 10 billion KRW. The POSCO Seawater Desalination facility, located in Gwangyang Bay Area in the Southern Sea, has produced 30,000 tons of fresh water per day since 2014. Since there has been an incident of red time in the area for three months in August, 2012, it is necessary to establish a warning system for red tide that threatens the stable operation of the seawater desalination facility. A red tide warning system can offer the seawater desalination facility manager customized services on red tide information and potential red tide inflow to the water intake. This study aimed to develop a red tide warning system in Gwangyang Bay Area by combining RS, modeling and monitoring technologies, which provides red tide forecasting information with which to effectively control the seawater desalination process. Using the proposed system, the seawater desalination facility manager can take phased measures to cope with the inflow of red tide. ACKNOWLEDGMENTS This research was supported by a grant(16IFIP-C088924-03) from Industrial Facilities & Infrastructure Research Program funded by Ministry of Land, Infrastructure and Transport(MOLIT) of the Korea government and the Korea Agency for Infrastructure Technology Advancement (KAIA). This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2014R1A1A2054975).

Solar powered desalination system using Fresnel lens

NASA Astrophysics Data System (ADS)

Sales, M. T. B. F.

2016-11-01

The Philippines is surrounded by coastal areas and these areas can be a potential source for potable water. This study aims to design and construct a solar powered desalination system using Fresnel lens. The experimental study was conducted using polluted salt water for the sample and desalination was carried out using the designed system. The desalination system was composed of the solar concentrator, solar still and the condenser system. The Fresnel lens was made of acrylic plastic and was an effective solar concentrator. Solar stills made of dark colored glass bottles were effective in absorbing the solar energy. The condenser system made of polybutylene and polystyrene were effective in condensing the vapor at ambient temperature. The shortest time of vaporization of the salt water was at 293 sec and the optimum angle of position of the lens was 36.42°. The amount of condensate collected was directly proportional to the amount of salt water in the solar still. The highest mean efficiency of the designed set-up was 34.82%. The water produced by the solar powered desalination system using Fresnel lens passed the standards set by WHO (World Health Organization) for drinking water.

Life Cycle Assessment for desalination: a review on methodology feasibility and reliability.

PubMed

Zhou, Jin; Chang, Victor W-C; Fane, Anthony G

2014-09-15

As concerns of natural resource depletion and environmental degradation caused by desalination increase, research studies of the environmental sustainability of desalination are growing in importance. Life Cycle Assessment (LCA) is an ISO standardized method and is widely applied to evaluate the environmental performance of desalination. This study reviews more than 30 desalination LCA studies since 2000s and identifies two major issues in need of improvement. The first is feasibility, covering three elements that support the implementation of the LCA to desalination, including accounting methods, supporting databases, and life cycle impact assessment approaches. The second is reliability, addressing three essential aspects that drive uncertainty in results, including the incompleteness of the system boundary, the unrepresentativeness of the database, and the omission of uncertainty analysis. This work can serve as a preliminary LCA reference for desalination specialists, but will also strengthen LCA as an effective method to evaluate the environment footprint of desalination alternatives. Copyright © 2014 Elsevier Ltd. All rights reserved.

Formation and fate of chlorination by-products in reverse osmosis desalination systems.

PubMed

Agus, Eva; Sedlak, David L

2010-03-01

Chlorination by-products may be formed during pretreatment or posttreatment disinfection in reverse osmosis (RO) desalination systems, potentially posing health, aesthetic and ecological risks. To assess the formation and fate of by-products under different conditions likely to be encountered in desalination systems, trihalomethanes, dihaloacetonitriles, haloacetic acids, and bromophenols were analyzed in water samples from a pilot-scale seawater desalination plant with a chlorine pretreatment system and in benchscale experiments designed to simulate other feed water conditions. In the pilot plant, RO rejection performance as low as 55% was observed for neutral, low-molecular-weight by-products such as chloroform or bromochloroacetonitrile. Benchscale chlorination experiments, conducted on seawater from various locations indicated significant temporal and spatial variability for all by-products, which could not be explained by measured concentrations of organic carbon or bulk parameters such as SUVA(254). When desalinated water was blended with freshwater, elevated concentrations of bromide in the blended water resulted in dihaloacetonitrile concentrations that were higher than those expected from dilution. In most situations, the concentration of chlorination by-products formed from continuous chlorination of seawater or blending of desalinated water and freshwater will not compromise water quality or pose significant risks to aquatic ecosystems. Copyright 2009 Elsevier Ltd. All rights reserved.

Use of simulated evaporation to assess the potential for scale formation during reverse osmosis desalination

USGS Publications Warehouse

Huff, G.F.

2004-01-01

The tendency of solutes in input water to precipitate efficiency lowering scale deposits on the membranes of reverse osmosis (RO) desalination systems is an important factor in determining the suitability of input water for desalination. Simulated input water evaporation can be used as a technique to quantitatively assess the potential for scale formation in RO desalination systems. The technique was demonstrated by simulating the increase in solute concentrations required to form calcite, gypsum, and amorphous silica scales at 25??C and 40??C from 23 desalination input waters taken from the literature. Simulation results could be used to quantitatively assess the potential of a given input water to form scale or to compare the potential of a number of input waters to form scale during RO desalination. Simulated evaporation of input waters cannot accurately predict the conditions under which scale will form owing to the effects of potentially stable supersaturated solutions, solution velocity, and residence time inside RO systems. However, the simulated scale-forming potential of proposed input waters could be compared with the simulated scale-forming potentials and actual scale-forming properties of input waters having documented operational histories in RO systems. This may provide a technique to estimate the actual performance and suitability of proposed input waters during RO.

Is irrigation with partial desalinated seawater a policy option for saving freshwater in the Kingdom of Saudi Arabia

NASA Astrophysics Data System (ADS)

Multsch, Sebastian; Alquwaizany, Abdulaziz S.; Lehnert, Karl-H.; Frede, Hans-Georg; Breuer, Lutz

2015-04-01

The agriculture sector consumes with 88 % a majority of the almost fossil water resources in the Kingdom of Saudi Arabia (KSA). Irrigation with saline water has been highlighted to be a promising technique to reduce fresh water consumption. Current desalination techniques, further developments, salt tolerant crop types and improved irrigation systems can potentially redesign future perspectives for irrigation agriculture, in particular by considering the growing desalination capacity in KSA (5 million m3 day-1 in 2003). Hence, we have analyzed the potential of using desalinated and partial desalinated seawater for growing crops in KSA by considering scenarios of salinity levels and desalination costs. The desalination process has been modelled with the ROSA© software considering a reverse osmosis (RO) plant. The spatial decision support system SPARE:WATER has been applied to assess the water footprint of crops (WFcrop). In order to maintain high crop yields, salts need to be washed out from the rooting zone, which requires the application of additional salt-free water. Therefore, high crop yields come along with additional water requirements and increased desalination effort and increased costs for proving high quality water. As an example, growing wheat with partial desalinated seawater from the Arabian Gulf with a RO plant has been investigated. Desalination reduces the salinity level from 76 dS m-1 to 0.5 dS m-1 considering two RO cycles, with cost of desalinized water in the range of 0.5 to 1.2 m-3. We acknowledge that cost only refer to desalination without considering others such as transport, water pumping or crop fertilization. The study shows that Boron is the most problematic salt component, because it is difficult to remove by RO and toxic in high concentrations for crops (wheat threshold of 0.5 to 1.0 mg l-1). The nationwide average WFcrop of wheat under surface irrigation is 2,628 m3 t-1 considering high water quality of 1 dS m-1 and 3,801 m3 t-1 at 12 dS m-1. Using sprinkler or drip irrigation systems the WFcrop decreases of about 20 % and 34 %, respectively. It can be shown that a salinity level larger than 9 dS m-1 increases leaching water requirement of wheat over proportional and that a salinity level of 9 dS m-1 reduces cost for irrigation water by about 11 % in comparison to the irrigation with nearly fresh water quality of 1 dS m-1. A trade-off analyses reveals that making desalinated seawater use profitable, cost need to be reduced below 0.2 m-3 for sprinkler and drip irrigation and even below 0.1 m-3 for widespread used surface irrigation systems. The authors gratefully acknowledge the support of the King Abdulaziz City for Science and Technology (KACST), Saudi Arabia, for funding the research Project No. 33-900 entitled 'Technology for desalinated seawater use in agriculture'.

Renewable Water: Direct Contact Membrane Distillation Coupled With Solar Ponds

NASA Astrophysics Data System (ADS)

Suarez, F. I.; Tyler, S. W.; Childress, A. E.

2010-12-01

The exponential population growth and the accelerated increase in the standard of living have increased significantly the global consumption of two precious resources: water and energy. These resources are intrinsically linked and are required to allow a high quality of human life. With sufficient energy, water may be harvested from aquifers, treated for potable reuse, or desalinated from brackish and seawater supplies. Even though the costs of desalination have declined significantly, traditional desalination systems still require large quantities of energy, typically from fossil fuels that will not allow these systems to produce water in a sustainable way. Recent advances in direct contact membrane distillation can take advantage of low-quality or renewable heat to desalinate brackish water, seawater or wastewater. Direct contact membrane distillation operates at low pressures and can use small temperature differences between the feed and permeate water to achieve a significant freshwater production. Therefore, a much broader selection of energy sources can be considered to drive thermal desalination. A promising method for providing renewable source of heat for direct contact membrane distillation is a solar pond, which is an artificially stratified water body that captures solar radiation and stores it as thermal energy at the bottom of the pond. In this work, a direct contact membrane distillation/solar pond coupled system is modeled and tested using a laboratory-scale system. Freshwater production rates on the order of 2 L day-1 per m2 of solar pond (1 L hr-1 per m2 of membrane area) can easily be achieved with minimal operating costs and under low pressures. While these rates are modest, they are six times larger than those produced by other solar pond-powered desalination systems - and they are likely to be increased if heat losses in the laboratory-scale system are reduced. Even more, this system operates at much lower costs than traditional desalination systems, thus, it can be used to meet the future needs of energy and water use in a sustainable way.

The Threat of Intentional Oil Spills to Desalination Plants in the Middle East: A U.S. Security Threat

DTIC Science & Technology

1998-04-01

desalination plants.”14 Kuwait and Qatar are almost entirely dependant on desalination plants already for their drinking water and with Qatar’s only aquifer ...rivers), below ground aquifers , and desalination facilities; the focus of this paper. Mary E. Morris most succinctly describes the basic water issues in...with different players and different issues: The first set involves the Jordan and Yarmuk River systems, as well as the West Bank and Gaza aquifers

Energy-positive wastewater treatment and desalination in an integrated microbial desalination cell (MDC)-microbial electrolysis cell (MEC)

NASA Astrophysics Data System (ADS)

Li, Yan; Styczynski, Jordyn; Huang, Yuankai; Xu, Zhiheng; McCutcheon, Jeffrey; Li, Baikun

2017-07-01

Simultaneous removal of nitrogen in municipal wastewater, metal in industrial wastewater and saline in seawater was achieved in an integrated microbial desalination cell-microbial electrolysis cell (MDC-MEC) system. Batch tests showed that more than 95.1% of nitrogen was oxidized by nitrification in the cathode of MDC and reduced by heterotrophic denitrification in the anode of MDC within 48 h, leading to the total nitrogen removal rate of 4.07 mg L-1 h-1. Combining of nitrogen removal and desalination in MDC effectively solved the problem of pH fluctuation in anode and cathode, and led to 63.7% of desalination. Power generation of MDC (293.7 mW m-2) was 2.9 times higher than the one without salt solution. The electric power of MDC was harvested by a capacitor circuit to supply metal reduction in a MEC, and 99.5% of lead (II) was removed within 48 h. A kinetic MDC model was developed to elucidate the correlation of voltage output and desalination efficiency. Ratio of wastewater and sea water was calculated for MDC optimal operation. Energy balance of nutrient removal, metal removal and desalination in the MDC-MEC system was positive (0.0267 kW h m-3), demonstrating the promise of utilizing low power output of MDCs.

New prospects for PV powered water desalination plants: case studies in Saudi Arabia: New prospects for PV powered water desalination plants

DOE PAGES

Fthenakis, Vasilis; Atia, Adam A.; Morin, Olivier; ...

2015-01-28

Increased water demand and increased drought episodes in the Middle East and other regions necessitate an expansion in desalination projects and create a great market opportunity for photovoltaics (PV). PV-powered desalination has previously been regarded as not being a cost-competitive solution when compared with conventionally powered desalination; however, the decline in PV costs over the last few years has changed this outlook. Here, this article presents up-to-date performance and cost analysis of reverse osmosis (RO) desalination powered with PV connected to the Saudi Arabian grid. Reference cases include relatively small (i.e., producing 6550 m 3 water per day) and largemore » (i.e., 190 000 m 3/day) desalination plants using seawater at a salinity of 40 000 ppm. We used data from a King Abdullah University for Science and Technology presentation and Hybrid Optimization Model for Electric Renewables 2.81 Energy Modeling Software (HOMER Energy LLC) in tandem with Desalination Economic Evaluation Program 4.0 (International Atomic Energy Agency) desalination software to analyze the techno-economic feasibility of these plants. The first phase of our work entailed a comparison between dual-axis high concentration PV (CPV) equipped with triple junction III/V solar cells and CdTe PV-powered RO systems. The estimated levelized cost of electricity from CPV is 0.16/kWh dollars, whereas that from CdTe PV is $0.10/kWh dollars and 0.09/kWh dollars for fixed-tilt and one-axis tracking systems, respectively. These costs are higher than the price of diesel-based grid electricity in the region because diesel fuel is heavily subsidized in Saudi Arabia.« less

Thermoeconomic analysis of an integrated multi-effect desalination thermal vapor compression (MED-TVC) system with a trigeneration system using triple-pressure HRSG

NASA Astrophysics Data System (ADS)

Ghaebi, Hadi; Abbaspour, Ghader

2018-05-01

In this research, thermoeconomic analysis of a multi-effect desalination thermal vapor compression (MED-TVC) system integrated with a trigeneration system with a gas turbine prime mover is carried out. The integrated system comprises of a compressor, a combustion chamber, a gas turbine, a triple-pressure (low, medium and high pressures) heat recovery steam generator (HRSG) system, an absorption chiller cycle (ACC), and a multi-effect desalination (MED) system. Low pressure steam produced in the HRSG is used to drive absorption chiller cycle, medium pressure is used in desalination system and high pressure superheated steam is used for heating purposes. For thermodynamic and thermoeconomic analysis of the proposed integrated system, Engineering Equation Solver (EES) is used by employing mass, energy, exergy, and cost balance equations for each component of system. The results of the modeling showed that with the new design, the exergy efficiency in the base design will increase to 57.5%. In addition, thermoeconomic analysis revealed that the net power, heating, fresh water and cooling have the highest production cost, respectively.

Model-based Extracted Water Desalination System for Carbon Sequestration

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

Gettings, Rachel; Dees, Elizabeth

The focus of this research effort centered around water recovery from high Total Dissolved Solids (TDS) extracted waters (180,000 mg/L) using a combination of water recovery (partial desalination) technologies. The research goals of this project were as follows: 1. Define the scope and test location for pilot-scale implementation of the desalination system, 2.Define a scalable, multi-stage extracted water desalination system that yields clean water, concentrated brine, and, salt from saline brines, and 3. Validate overall system performance with field-sourced water using GE pre-pilot lab facilities. Conventional falling film-mechanical vapor recompression (FF-MVR) technology was established as a baseline desalination process. Amore » quality function deployment (QFD) method was used to compare alternate high TDS desalination technologies to the base case FF-MVR technology, including but not limited to: membrane distillation (MD), forward osmosis (FO), and high pressure reverse osmosis (HPRO). Technoeconomic analysis of high pressure reverse osmosis (HPRO) was performed comparing the following two cases: 1. a hybrid seawater RO (SWRO) plus HPRO system and 2. 2x standard seawater RO system, to achieve the same total pure water recovery rate. Pre-pilot-scale tests were conducted using field production water to validate key process steps for extracted water pretreatment. Approximately 5,000 gallons of field produced water was processed through, microfiltration, ultrafiltration, and steam regenerable sorbent operations. Improvements in membrane materials of construction were considered as necessary next steps to achieving further improvement in element performance at high pressure. Several modifications showed promising results in their ability to withstand close to 5,000 PSI without gross failure.« less

Forward osmosis niches in seawater desalination and wastewater reuse.

PubMed

Valladares Linares, R; Li, Z; Sarp, S; Bucs, Sz S; Amy, G; Vrouwenvelder, J S

2014-12-01

This review focuses on the present status of forward osmosis (FO) niches in two main areas: seawater desalination and wastewater reuse. Specific applications for desalination and impaired-quality water treatment and reuse are described, as well as the benefits, advantages, challenges, costs and knowledge gaps on FO hybrid systems are discussed. FO can play a role as a bridge to integrate upstream and downstream water treatment processes, to reduce the energy consumption of the entire desalination or water recovery and reuse processes, thus achieving a sustainable solution for the water-energy nexus. FO hybrid membrane systems showed to have advantages over traditional membrane process like high pressure reverse osmosis and nanofiltration for desalination and wastewater treatment: (i) chemical storage and feed water systems may be reduced for capital, operational and maintenance cost, (ii) water quality is improved, (iii) reduced process piping costs, (iv) more flexible treatment units, and (v) higher overall sustainability of the desalination and wastewater treatment process. Nevertheless, major challenges make FO systems not yet a commercially viable technology, the most critical being the development of a high flux membrane, capable of maintaining an elevated salt rejection and a reduced internal concentration polarization effect, and the availability of appropriate draw solutions (cost effective and non-toxic), which can be recirculated via an efficient recovery process. This review article highlights the features of hybrid FO systems and specifically provides the state-of-the-art applications in the water industry in a novel classification and based on the latest developments toward scaling up these systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

PubMed

Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

2015-12-01

The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Saline Groundwater from Coastal Aquifers As a Source for Desalination.

PubMed

Stein, Shaked; Russak, Amos; Sivan, Orit; Yechieli, Yoseph; Rahav, Eyal; Oren, Yoram; Kasher, Roni

2016-02-16

Reverse osmosis (RO) seawater desalination is currently a widespread means of closing the gap between supply and demand for potable water in arid regions. Currently, one of the main setbacks of RO operation is fouling, which hinders membrane performance and induces pressure loss, thereby reducing system efficiency. An alternative water source is saline groundwater with salinity close to seawater, pumped from beach wells in coastal aquifers which penetrate beneath the freshwater-seawater interface. In this research, we studied the potential use of saline groundwater of the coastal aquifer as feedwater for desalination in comparison to seawater using fieldwork and laboratory approaches. The chemistry, microbiology and physical properties of saline groundwater were characterized and compared with seawater. Additionally, reverse osmosis desalination experiments in a cross-flow system were performed, evaluating the permeate flux, salt rejection and fouling propensities of the different water types. Our results indicated that saline groundwater was significantly favored over seawater as a feed source in terms of chemical composition, microorganism content, silt density, and fouling potential, and exhibited better desalination performance with less flux decline. Saline groundwater may be a better water source for desalination by RO due to lower fouling potential, and reduced pretreatment costs.

Bioelectrochemical systems-driven directional ion transport enables low-energy water desalination, pollutant removal, and resource recovery.

PubMed

Chen, Xi; Liang, Peng; Zhang, Xiaoyuan; Huang, Xia

2016-09-01

Bioelectrochemical systems (BESs) are integrated water treatment technologies that generate electricity using organic matter in wastewater. In situ use of bioelectricity can direct the migration of ionic substances in a BES, thereby enabling water desalination, resource recovery, and valuable substance production. Recently, much attention has been placed on the microbial desalination cells in BESs to drive water desalination, and various configurations have optimized electricity generation and desalination performance and also coupled hydrogen production, heavy metal reduction, and other reactions. In addition, directional transport of other types of charged ions can remediate polluted groundwater, recover nutrient, and produce valuable substances. To better promote the practical application, the use of BESs as directional drivers of ionic substances requires further optimization to improve energy use efficiency and treatment efficacy. This article reviews existing researches on BES-driven directional ion transport to treat wastewater and identifies a few key factors involved in efficiency optimization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Life cycle cost of a hybrid forward osmosis - low pressure reverse osmosis system for seawater desalination and wastewater recovery.

PubMed

Valladares Linares, R; Li, Z; Yangali-Quintanilla, V; Ghaffour, N; Amy, G; Leiknes, T; Vrouwenvelder, J S

2016-01-01

In recent years, forward osmosis (FO) hybrid membrane systems have been investigated as an alternative to conventional high-pressure membrane processes (i.e. reverse osmosis (RO)) for seawater desalination and wastewater treatment and recovery. Nevertheless, their economic advantage in comparison to conventional processes for seawater desalination and municipal wastewater treatment has not been clearly addressed. This work presents a detailed economic analysis on capital and operational expenses (CAPEX and OPEX) for: i) a hybrid forward osmosis - low-pressure reverse osmosis (FO-LPRO) process, ii) a conventional seawater reverse osmosis (SWRO) desalination process, and iii) a membrane bioreactor - reverse osmosis - advanced oxidation process (MBR-RO-AOP) for wastewater treatment and reuse. The most important variables affecting economic feasibility are obtained through a sensitivity analysis of a hybrid FO-LPRO system. The main parameters taken into account for the life cycle costs are the water quality characteristics (similar feed water and similar water produced), production capacity of 100,000 m(3) d(-1) of potable water, energy consumption, materials, maintenance, operation, RO and FO module costs, and chemicals. Compared to SWRO, the FO-LPRO systems have a 21% higher CAPEX and a 56% lower OPEX due to savings in energy consumption and fouling control. In terms of the total water cost per cubic meter of water produced, the hybrid FO-LPRO desalination system has a 16% cost reduction compared to the benchmark for desalination, mainly SWRO. Compared to the MBR-RO-AOP, the FO-LPRO systems have a 7% lower CAPEX and 9% higher OPEX, resulting in no significant cost reduction per m(3) produced by FO-LPRO. Hybrid FO-LPRO membrane systems are shown to have an economic advantage compared to current available technology for desalination, and comparable costs with a wastewater treatment and recovery system. Based on development on FO membrane modules, packing density, and water permeability, the total water cost could be further reduced. Copyright © 2015 Elsevier Ltd. All rights reserved.

Graphene-based Recyclable Photo-Absorbers for High-Efficiency Seawater Desalination.

PubMed

Wang, Xiangqing; Ou, Gang; Wang, Ning; Wu, Hui

2016-04-13

Today's scientific advances in water desalination dramatically increase our ability to transform seawater into fresh water. As an important source of renewable energy, solar power holds great potential to drive the desalination of seawater. Previously, solar assisted evaporation systems usually relied on highly concentrated sunlight or were not suitable to treat seawater or wastewater, severely limiting the large scale application of solar evaporation technology. Thus, a new strategy is urgently required in order to overcome these problems. In this study, we developed a solar thermal evaporation system based on reduced graphene oxide (rGO) decorated with magnetic nanoparticles (MNPs). Because this material can absorb over 95% of sunlight, we achieved high evaporation efficiency up to 70% under only 1 kW m(-2) irradiation. Moreover, it could be separated from seawater under the action of magnetic force by decorated with MNPs. Thus, this system provides an advantage of recyclability, which can significantly reduce the material consumptions. Additionally, by using photoabsorbing bulk or layer materials, the deposition of solutes offen occurs in pores of materials during seawater desalination, leading to the decrease of efficiency. However, this problem can be easily solved by using MNPs, which suggests this system can be used in not only pure water system but also high-salinity wastewater system. This study shows good prospects of graphene-based materials for seawater desalination and high-salinity wastewater treatment.

Characterization of saline groundwater across the coastal aquifer of Israel as resource for desalination

NASA Astrophysics Data System (ADS)

Stein, Shaked; Russak, Amos; Sivan, Orit; Yechieli, Yospeh; Oren, Yoram; Kasher, Roni

2015-04-01

In arid countries with access to marine water seawater desalination is becoming an important water source in order to deal with the water scarcity and population growth. Seawater reverse osmosis (RO) facilities use open seawater intake, which requires pretreatment processes to remove particles in order to avoid fouling of the RO membrane. In small and medium size desalination facilities, an alternative water source can be saline groundwater in coastal aquifers. Using saline groundwater from boreholes near the shore as feed water may have the advantage of natural filtration and low organic content. It will also reduce operation costs of pretreatment. Another advantage of using groundwater is its availability in highly populated areas, where planning of large RO desalination plants is difficult and expensive due to real-estate prices. Pumping saline groundwater underneath the freshwater-seawater interface (FSI) might shift the interface towards the sea, thus rehabilitating the fresh water reservoirs in the aquifer. In this research, we tested the potential use of saline groundwater in the coastal aquifer of Israel as feed water for desalination using field work and desalination experiments. Specifically, we sampled the groundwater from a pumping well 100 m from the shore of Tel-Aviv and sea water from the desalination plant in Ashqelon, Israel. We used an RO cross flow system in a pilot plant in order to compare between the two water types in terms of permeate flux, permeate flux decline, salt rejection of the membrane and the fouling on the membrane. The feed, brine and fresh desalinated water from the outlet of the desalination system were chemically analyzed and compared. Field measurements of dissolved oxygen, temperature, pH and salinity were also conducted in situ. Additionally, SDI (silt density index), which is an important index for desalination, and total organic carbon that has a key role in organic fouling and development of biofouling, were measured and compared. The results have shown that using saline groundwater underneath the FSI as a resource for RO desalination process is beneficial in terms of fluxes: the flux reduction in the seawater desalination was 16% of the initial flux, while the flux reduction with the saline groundwater was only 9%. The SDI and total organic carbon were lower in saline groundwater than in seawater, which support the flux results. Therefore, using saline groundwater as feed water for desalination may be advantageous because of lower operational costs and reduced applied pressure needed and energy usage.

Numerical Study on Radiation Effects to Evaporator in Natural Vacuum Solar Desalination System

NASA Astrophysics Data System (ADS)

Siregar, R. E. T.; Ronowikarto, A. D.; Setyawan, E. Y.; Ambarita, H.

2018-01-01

The need for clean water is increasing day by day due to the increasing factor of living standard of mankind, hence designed natural vacuum solar desalination. The natural vacuum Solar desalination is studied experimentally. A small-scale natural vacuum desalination study consists of evaporator and condenser as the main components designed and manufactured. To transfer heat from the solar collector into the evaporator, the fluid transfer system uses a pump powered by a solar cell. Thus, solar collectors are called hybrid solar collectors. The main purpose of this exposure is to know the characteristics of the radiation effects on incoming energy on the evaporator during the process. This system is tested by exposing the unit to the solar radiation in the 4th floor building in Medan. The experiment was conducted from 8.00 to 16.00 local time. The results show that natural vacuum solar desalination with hybrid solar collectors can be operated perfectly. If the received radiation is high, then the incoming energy received by the evaporator will also be high. From measurements with HOBO microstation, obtained the highest radiation 695.6 W/m2, and the calculation result of incoming energy received evaporator obtained highest result 1807.293 W.

Reverse osmosis desalination: water sources, technology, and today's challenges.

PubMed

Greenlee, Lauren F; Lawler, Desmond F; Freeman, Benny D; Marrot, Benoit; Moulin, Philippe

2009-05-01

Reverse osmosis membrane technology has developed over the past 40 years to a 44% share in world desalting production capacity, and an 80% share in the total number of desalination plants installed worldwide. The use of membrane desalination has increased as materials have improved and costs have decreased. Today, reverse osmosis membranes are the leading technology for new desalination installations, and they are applied to a variety of salt water resources using tailored pretreatment and membrane system design. Two distinct branches of reverse osmosis desalination have emerged: seawater reverse osmosis and brackish water reverse osmosis. Differences between the two water sources, including foulants, salinity, waste brine (concentrate) disposal options, and plant location, have created significant differences in process development, implementation, and key technical problems. Pretreatment options are similar for both types of reverse osmosis and depend on the specific components of the water source. Both brackish water and seawater reverse osmosis (RO) will continue to be used worldwide; new technology in energy recovery and renewable energy, as well as innovative plant design, will allow greater use of desalination for inland and rural communities, while providing more affordable water for large coastal cities. A wide variety of research and general information on RO desalination is available; however, a direct comparison of seawater and brackish water RO systems is necessary to highlight similarities and differences in process development. This article brings to light key parameters of an RO process and process modifications due to feed water characteristics.

Low Temperature Geothermal Resource Assessment for Membrane Distillation Desalination in the United States

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

Akar, Sertac; Turchi, Craig

Substantial drought and declines in potable groundwater in the United States over the last decade has increased the demand for fresh water. Desalination of saline water such as brackish surface or groundwater, seawater, brines co-produced from oil and gas operations, industrial wastewater, blow-down water from power plant cooling towers, and agriculture drainage water can reduce the volume of water that requires disposal while providing a source of high-quality fresh water for industrial or commercial use. Membrane distillation (MD) is a developing technology that uses low-temperature thermal energy for desalination. Geothermal heat can be an ideal thermal-energy source for MD desalinationmore » technology, with a target range of $1/m3 to $2/m3 for desalinated water depending on the cost of heat. Three different cases were analyzed to estimate levelized cost of heat (LCOH) for integration of MD desalination technology with low-grade geothermal heat: (1) residual heat from injection brine at a geothermal power plant, (2) heat from existing underutilized low-temperature wells, and (3) drilling new wells for low-temperature resources. The Central and Western United States have important low-temperature (<90 degrees C) geothermal resource potential with wide geographic distribution, but these resources are highly underutilized because they are inefficient for power production. According to the USGS, there are 1,075 identified low temperature hydrothermal systems, 55 low temperature sedimentary systems and 248 identified medium to high temperature geothermal systems in the United States. The estimated total beneficial heat potential from identified low temperature hydrothermal geothermal systems and residual beneficial heat from medium to high temperature systems is estimated as 36,300 MWth, which could theoretically produce 1.4 to 7 million m3/day of potable water, depending on desalination efficiency.« less

Coupling desalination and energy storage with redox flow electrodes.

PubMed

Hou, Xianhua; Liang, Qian; Hu, Xiaoqiao; Zhou, Yu; Ru, Qiang; Chen, Fuming; Hu, Shejun

2018-06-26

Both freshwater shortage and energy crisis are global issues. Herein, we present a double-function system of faradaic desalination and a redox flow battery consisting of VCl3|NaI redox flow electrodes and a feed stream. The system has a nominal cell potential (E0 = +0.79 V). During the discharge process, the salt ions in the feed are extracted by the redox reaction of the flow electrodes, which is indicated by salt removal. Stable and reversible salt removal capacity and electricity can be achieved up to 30 cycles. The energy consumption is as low as 10.27 kJ mol-1 salt. The energy efficiency is as high as 50% in the current aqueous redox flow battery. With energy recovery, the desalination energy consumption decreases greatly to 5.38 kJ mol-1; this is the lowest reported value to date. This "redox flow battery desalination generator" can be operated in a voltage range of 0.3-1.1 V. Our research provides a novel method for obtaining energy-saving desalination and redox flow batteries.

Numerical Study on Natural Vacuum Solar Desalination System with Varying Heat Source Temperature

NASA Astrophysics Data System (ADS)

Ambarita, H.

2017-03-01

A natural vacuum desalination unit with varying low grade heat source temperature is investigated numerically. The objective is to explore the effects of the variable temperature of the low grade heat source on performances and characteristics of the desalination unit. The specifications of the desalination unit are naturally vacuumed with surface area of seawater in evaporator and heating coil are 0.2 m2 and 0.188 m2, respectively. Temperature of the heating coil is simulated based on the solar radiation in the Medan city. A program to solve the governing equations in forward time step marching technique is developed. Temperature of the evaporator, fresh water production rate, and thermal efficiency of the desalination unit are analysed. Simulation is performed for 9 hours, it starts from 8.00 and finishes at 17.00 of local time. The results show that, the desalination unit with operation time of 9 hours can produce 5.705 L of freshwater and thermal efficiency is 81.8 %. This reveals that varying temperature of the heat source of natural vacuum desalination unit shows better performance in comparison with constant temperature of the heat source.

Advanced Multi-Effect Distillation System for Desalination Using Waste Heat fromGas Brayton Cycles

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

Haihua Zhao; Per F. Peterson

2012-10-01

Generation IV high temperature reactor systems use closed gas Brayton Cycles to realize high thermal efficiency in the range of 40% to 60%. The waste heat is removed through coolers by water at substantially greater average temperature than in conventional Rankine steam cycles. This paper introduces an innovative Advanced Multi-Effect Distillation (AMED) design that can enable the production of substantial quantities of low-cost desalinated water using waste heat from closed gas Brayton cycles. A reference AMED design configuration, optimization models, and simplified economics analysis are presented. By using an AMED distillation system the waste heat from closed gas Brayton cyclesmore » can be fully utilized to desalinate brackish water and seawater without affecting the cycle thermal efficiency. Analysis shows that cogeneration of electricity and desalinated water can increase net revenues for several Brayton cycles while generating large quantities of potable water. The AMED combining with closed gas Brayton cycles could significantly improve the sustainability and economics of Generation IV high temperature reactors.« less

Effects of Bloom-Forming Algae on Fouling of Integrated Membrane Systems in Seawater Desalination

ERIC Educational Resources Information Center

Ladner, David Allen

2009-01-01

Combining low- and high-pressure membranes into an integrated membrane system is an effective treatment strategy for seawater desalination. Low-pressure microfiltration (MF) and ultrafiltration (UF) membranes remove particulate material, colloids, and high-molecular-weight organics leaving a relatively foulant-free salt solution for treatment by…

CSP cogeneration of electricity and desalinated water at the Pentakomo field facility

NASA Astrophysics Data System (ADS)

Papanicolas, C. N.; Bonanos, A. M.; Georgiou, M. C.; Guillen, E.; Jarraud, N.; Marakkos, C.; Montenon, A.; Stiliaris, E.; Tsioli, E.; Tzamtzis, G.; Votyakov, E. V.

2016-05-01

The Cyprus Institute's Pentakomo Field Facility (PFF) is a major infrastructure for research, development and testing of technologies relating to concentrated solar power (CSP) and solar seawater desalination. It is located at the south coast of Cyprus near the sea and its environmental conditions are fully monitored. It provides a test facility specializing in the development of CSP systems suitable for island and coastal environments with particular emphasis on small units (<25 MWth) endowed with substantial storage, suitable for use in isolation or distributed in small power grids. The first major experiment to take place at the PFF concerns the development of a pilot/experimental facility for the co-generation of electricity and desalinated seawater from CSP. Specifically, the experimental plant consists of a heliostat-central receiver system for solar harvesting, thermal energy storage in molten salts followed by a Rankine cycle for electricity production and a multiple-effect distillation (MED) unit for desalination.

Microbial desalination cell with sulfonated sodium poly(ether ether ketone) as cation exchange membranes for enhancing power generation and salt reduction.

PubMed

Moruno, Francisco Lopez; Rubio, Juan E; Atanassov, Plamen; Cerrato, José M; Arges, Christopher G; Santoro, Carlo

2018-06-01

Microbial desalination cell (MDC) is a bioelectrochemical system capable of oxidizing organics, generating electricity, while reducing the salinity content of brine streams. As it is designed, anion and cation exchange membranes play an important role on the selective removal of ions from the desalination chamber. In this work, sulfonated sodium (Na + ) poly(ether ether ketone) (SPEEK) cation exchange membranes (CEM) were tested in combination with quaternary ammonium chloride poly(2,6-dimethyl 1,4-phenylene oxide) (QAPPO) anion exchange membrane (AEM). Non-patterned and patterned (varying topographical features) CEMs were investigated and assessed in this work. The results were contrasted against a commercially available CEM. This work used real seawater from the Pacific Ocean in the desalination chamber. The results displayed a high desalination rate and power generation for all the membranes, with a maximum of 78.6±2.0% in salinity reduction and 235±7mWm -2 in power generation for the MDCs with the SPEEK CEM. Desalination rate and power generation achieved are higher with synthesized SPEEK membranes when compared with an available commercial CEM. An optimized combination of these types of membranes substantially improves the performances of MDC, making the system more suitable for real applications. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Simulating the impact of brine from desalination plants on the salinity of the Persian/Arabian Gulf

NASA Astrophysics Data System (ADS)

Eltahir, E. A. B.; Ibrahim, H. D.

2016-12-01

The Middle East has an arid climate and very little freshwater from river runoff, which has forced a rapid expansion of desalination plants in the region in order to meet current and future freshwater demand due to rising population. The Gulf is the source of feedwater and sink of concentrated discharge (brine) for plants producing more than half of the world's desalination capacity. Moreover, the Gulf is one of the most saline water bodies in the world due to large evaporation that far exceeds the input of freshwater from precipitation and river runoff. An increase in salinity at the regional scale due to brine discharge may reduce the quality of feedwater to plants and efficiency of desalination, and at the basin scale, a rise in salinity may change the dynamics of water circulation and adversely impact the marine biota. Here we present modeling results from simulating the impact of desalination on the natural Gulf environment using a coupled Gulf-atmosphere regional model (GARM). GARM is the first two-way coupled model developed for the Gulf system. The hydrodynamic component of GARM is the unstructured grid finite volume coastal ocean model (FVCOM) and the atmosphere component of GARM is the MIT regional climate model (MRCM), both of which have been widely used in simulating regional ocean and atmospheric dynamics. Desalination activity is incorporated into GARM as a boundary condition and the Gulf system is simulated for a ten-year time period in order to quantify the impact of brine discharge both at regional and basin scales. These results will be useful for desalination plant design and planning for current and future water security in the region.

Sodium Hydroxide Production from Seawater Desalination Brine: Process Design and Energy Efficiency.

PubMed

Du, Fengmin; Warsinger, David M; Urmi, Tamanna I; Thiel, Gregory P; Kumar, Amit; Lienhard V, John H

2018-05-15

The ability to increase pH is a crucial need for desalination pretreatment (especially in reverse osmosis) and for other industries, but processes used to raise pH often incur significant emissions and nonrenewable resource use. Alternatively, waste brine from desalination can be used to create sodium hydroxide, via appropriate concentration and purification pretreatment steps, for input into the chlor-alkali process. In this work, an efficient process train (with variations) is developed and modeled for sodium hydroxide production from seawater desalination brine using membrane chlor-alkali electrolysis. The integrated system includes nanofiltration, concentration via evaporation or mechanical vapor compression, chemical softening, further ion-exchange softening, dechlorination, and membrane electrolysis. System productivity, component performance, and energy consumption of the NaOH production process are highlighted, and their dependencies on electrolyzer outlet conditions and brine recirculation are investigated. The analysis of the process also includes assessment of the energy efficiency of major components, estimation of system operating expense and comparison with similar processes. The brine-to-caustic process is shown to be technically feasible while offering several advantages, that is, the reduced environmental impact of desalination through lessened brine discharge, and the increase in the overall water recovery ratio of the reverse osmosis facility. Additionally, best-use conditions are given for producing caustic not only for use within the plant, but also in excess amounts for potential revenue.

Long-term performance and characterization of microbial desalination cells in treating domestic wastewater.

PubMed

Luo, Haiping; Xu, Pei; Ren, Zhiyong

2012-09-01

Microbial desalination cell represents a new technology for simultaneous wastewater treatment, water desalination, and energy production. This study characterized the long-term performance of MDC during wastewater treatment and identified the key factors that caused performance decline. The 8-month operation shows that MDC performance decreased over time, as indicated by a 47% decline in current density, a 46% drop in Columbic efficiency, and a 27% decrease in desalination efficiency. Advanced electrochemical, microscopy, and spectroscopy analyses all confirmed biofouling on the anion exchange membrane, which increased system resistance and reduced ionic transfer and energy conversion efficiency. Minor chemical scaling was found on the cation exchange membrane surface. Microbial communities became less diverse at the end of operation, and Proteobacteria spp. was dominant on both anode and AEM fouling layer surface. These results provide insights into the viability of long-term MDC operation on reactor performance and direct system development through membrane optimization. Copyright © 2012 Elsevier Ltd. All rights reserved.

Graphene oxide-based efficient and scalable solar desalination under one sun with a confined 2D water path

PubMed Central

Li, Xiuqiang; Xu, Weichao; Tang, Mingyao; Zhou, Lin; Zhu, Bin; Zhu, Shining; Zhu, Jia

2016-01-01

Because it is able to produce desalinated water directly using solar energy with minimum carbon footprint, solar steam generation and desalination is considered one of the most important technologies to address the increasingly pressing global water scarcity. Despite tremendous progress in the past few years, efficient solar steam generation and desalination can only be achieved for rather limited water quantity with the assistance of concentrators and thermal insulation, not feasible for large-scale applications. The fundamental paradox is that the conventional design of direct absorber−bulk water contact ensures efficient energy transfer and water supply but also has intrinsic thermal loss through bulk water. Here, enabled by a confined 2D water path, we report an efficient (80% under one-sun illumination) and effective (four orders salinity decrement) solar desalination device. More strikingly, because of minimized heat loss, high efficiency of solar desalination is independent of the water quantity and can be maintained without thermal insulation of the container. A foldable graphene oxide film, fabricated by a scalable process, serves as efficient solar absorbers (>94%), vapor channels, and thermal insulators. With unique structure designs fabricated by scalable processes and high and stable efficiency achieved under normal solar illumination independent of water quantity without any supporting systems, our device represents a concrete step for solar desalination to emerge as a complementary portable and personalized clean water solution. PMID:27872280

Graphene oxide-based efficient and scalable solar desalination under one sun with a confined 2D water path.

PubMed

Li, Xiuqiang; Xu, Weichao; Tang, Mingyao; Zhou, Lin; Zhu, Bin; Zhu, Shining; Zhu, Jia

2016-12-06

Because it is able to produce desalinated water directly using solar energy with minimum carbon footprint, solar steam generation and desalination is considered one of the most important technologies to address the increasingly pressing global water scarcity. Despite tremendous progress in the past few years, efficient solar steam generation and desalination can only be achieved for rather limited water quantity with the assistance of concentrators and thermal insulation, not feasible for large-scale applications. The fundamental paradox is that the conventional design of direct absorber-bulk water contact ensures efficient energy transfer and water supply but also has intrinsic thermal loss through bulk water. Here, enabled by a confined 2D water path, we report an efficient (80% under one-sun illumination) and effective (four orders salinity decrement) solar desalination device. More strikingly, because of minimized heat loss, high efficiency of solar desalination is independent of the water quantity and can be maintained without thermal insulation of the container. A foldable graphene oxide film, fabricated by a scalable process, serves as efficient solar absorbers (>94%), vapor channels, and thermal insulators. With unique structure designs fabricated by scalable processes and high and stable efficiency achieved under normal solar illumination independent of water quantity without any supporting systems, our device represents a concrete step for solar desalination to emerge as a complementary portable and personalized clean water solution.

Massive arrival of desalinated seawater in a regional urban water cycle: A multi-isotope study (B, S, O, H).

PubMed

Kloppmann, W; Negev, Ido; Guttman, Joseph; Goren, Orly; Gavrieli, Ittai; Guerrot, Catherine; Flehoc, Christine; Pettenati, Marie; Burg, Avihu

2018-04-01

"Man-made" or unconventional freshwater, like desalinated seawater or reclaimed effluents, is increasingly introduced into regional water cycles in arid or semi-arid countries. We show that the breakthrough of reverse osmosis-derived freshwater in the largely engineered water cycle of the greater Tel Aviv region (Dan Region) has profoundly changed previous isotope fingerprints. This new component can be traced throughout the system, from the drinking water supply, through sewage, treated effluents, and artificially recharged groundwater at the largest Soil-Aquifer Treatment system in the Middle East (Shafdan) collecting all the Dan region sewage. The arrival of the new water type (desalinated seawater) in 2007 and its predominance since 2010 constitutes an unplanned, large-scale, long-term tracer test and the monitoring of the breakthrough of desalination-specific fingerprints in the aquifer system of Shafdan allowed to get new insights on the water and solute flow and behavior in engineered groundwater systems. Our approach provides an investigation tool for the urban water cycle, allowing estimating the contribution of diverse freshwater sources, and an environmental tracing method for better constraining the long-term behavior and confinement of aquifer systems with managed recharge. Copyright © 2017. Published by Elsevier B.V.

Formation of hazardous inorganic by-products during electrolysis of seawater as a disinfection process for desalination.

PubMed

Oh, Byung Soo; Oh, Sang Guen; Hwang, Youn Young; Yu, Hye-Weon; Kang, Joon-Wun; Kim, In S

2010-11-01

From our previous study, an electrochemical process was determined to be a promising tool for disinfection in a seawater desalination system, but an investigation on the production of several hazardous by-products is still required. In this study, a more intensive exploration of the formation patterns of perchlorate and bromate during the electrolysis of seawater was conducted. In addition, the rejection efficiencies of the targeted by-products by membrane processes (microfiltration and seawater reverse osmosis) were investigated to uncover the concentrations remaining in the final product from a membrane-based seawater desalination system for the production of drinking water. On the electrolysis of seawater, perchlorate did not provoke any problem due to the low concentrations formed, but bromate was produced at a much higher level, resulting in critical limitation in the application of the electrochemical process to the desalination of seawater. Even though the formed bromate was rejected via microfiltration and reverse osmosis during the 1st and 2nd passes, the residual concentration was a few orders of magnitude higher than the USEPA regulation. Consequently, it was concluded that the application of the electrochemical process to seawater desalination cannot be recommended without the control of bromate. Copyright © 2010 Elsevier B.V. All rights reserved.

Stacked microbial desalination cells to enhance water desalination efficiency.

PubMed

Chen, Xi; Xia, Xue; Liang, Peng; Cao, Xiaoxin; Sun, Haotian; Huang, Xia

2011-03-15

Microbial desalination cell (MDC) is a new method to obtain clean water from brackish water using electricity generated from organic matters by exoelectrogenic bacteria. Anions and cations, derived from salt solution filled in the desalination chamber between the anode and cathode, move to the anode and cathode chambers under the force of electrical field, respectively. On the basis of the primitive single-desalination-chambered MDC, stacked microbial desalination cells (SMDCs) were developed in order to promote the desalination rate in the present study. The effects of desalination chamber number and external resistance were investigated. Results showed that a remarkable increase in the total desalination rate (TDR) could be obtained by means of increasing the desalination cell number and reducing the external resistance, which caused the charge transfer efficiency increased since the SMDCs enabled more pairs of ions separated while one electron passed through the external circuit. The maximum TDR of 0.0252 g/h was obtained using a two-desalination-chambered SMDC with an external resistance of 10 Ω, which was 1.4 times that of single-desalination-chambered MDC. SMDCs proved to be an effective approach to increase the total water desalination rate if provided a proper desalination chamber number and external resistance.

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

Akar, Sertac; Turchi, Craig

Substantial drought and declines in potable groundwater in the United States over the last decade has increased the demand for fresh water. Desalination of saline water such as brackish surface or groundwater, seawater, brines co-produced from oil and gas operations, industrial wastewater, blow-down water from power plant cooling towers, and agriculture drainage water can reduce the volume of water that requires disposal while providing a source of high-quality fresh water for industrial or commercial use. Membrane distillation (MD) is a developing technology that uses low-temperature thermal energy for desalination. Geothermal heat can be an ideal thermal-energy source for MD desalinationmore » technology, with a target range of $1/m3 to $2/m3 for desalinated water depending on the cost of heat. Three different cases were analyzed to estimate levelized cost of heat (LCOH) for integration of MD desalination technology with low-grade geothermal heat: (1) residual heat from injection brine at a geothermal power plant, (2) heat from existing underutilized low-temperature wells, and (3) drilling new wells for low-temperature resources. The Central and Western United States have important low-temperature (<90 degrees C) geothermal resource potential with wide geographic distribution, but these resources are highly underutilized because they are inefficient for power production. According to the USGS, there are 1,075 identified low temperature hydrothermal systems, 55 low temperature sedimentary systems and 248 identified medium to high temperature geothermal systems in the United States. The estimated total beneficial heat potential from identified low temperature hydrothermal geothermal systems and residual beneficial heat from medium to high temperature systems is estimated as 36,300 MWth, which could theoretically produce 1.4 to 7 million m3/day of potable water, depending on desalination efficiency.« less

Particulate-free porous silicon networks for efficient capacitive deionization water desalination

PubMed Central

Metke, Thomas; Westover, Andrew S.; Carter, Rachel; Oakes, Landon; Douglas, Anna; Pint, Cary L.

2016-01-01

Energy efficient water desalination processes employing low-cost and earth-abundant materials is a critical step to sustainably manage future human needs for clean water resources. Here we demonstrate that porous silicon – a material harnessing earth abundance, cost, and environmental/biological compatibility is a candidate material for water desalination. With appropriate surface passivation of the porous silicon material to prevent surface corrosion in aqueous environments, we show that porous silicon templates can enable salt removal in capacitive deionization (CDI) ranging from 0.36% by mass at the onset from fresh to brackish water (10 mM, or 0.06% salinity) to 0.52% in ocean water salt concentrations (500 mM, or ~0.3% salinity). This is on par with reports of most carbon nanomaterial based CDI systems based on particulate electrodes and covers the full salinity range required of a CDI system with a total ocean-to-fresh water required energy input of ~1.45 Wh/L. The use of porous silicon for CDI enables new routes to directly couple water desalination technology with microfluidic systems and photovoltaics that natively use silicon materials, while mitigating adverse effects of water contamination occurring from nanoparticulate-based CDI electrodes. PMID:27101809

Particulate-free porous silicon networks for efficient capacitive deionization water desalination.

PubMed

Metke, Thomas; Westover, Andrew S; Carter, Rachel; Oakes, Landon; Douglas, Anna; Pint, Cary L

2016-04-22

Energy efficient water desalination processes employing low-cost and earth-abundant materials is a critical step to sustainably manage future human needs for clean water resources. Here we demonstrate that porous silicon - a material harnessing earth abundance, cost, and environmental/biological compatibility is a candidate material for water desalination. With appropriate surface passivation of the porous silicon material to prevent surface corrosion in aqueous environments, we show that porous silicon templates can enable salt removal in capacitive deionization (CDI) ranging from 0.36% by mass at the onset from fresh to brackish water (10 mM, or 0.06% salinity) to 0.52% in ocean water salt concentrations (500 mM, or ~0.3% salinity). This is on par with reports of most carbon nanomaterial based CDI systems based on particulate electrodes and covers the full salinity range required of a CDI system with a total ocean-to-fresh water required energy input of ~1.45 Wh/L. The use of porous silicon for CDI enables new routes to directly couple water desalination technology with microfluidic systems and photovoltaics that natively use silicon materials, while mitigating adverse effects of water contamination occurring from nanoparticulate-based CDI electrodes.

Economic and Policy Drivers of Agricultural Water Desalination in California's Central Valley

NASA Astrophysics Data System (ADS)

Welle, P.; Medellin-Azuara, J.; Viers, J. H.; Mauter, M.

2016-12-01

Agriculture in arid regions is threatened by the twin stresses of soil salinity and uncertain water availability. Recently, water desalination has been a proposed solution for mitigating the effects of drought, soil salinization, and the ecological impacts of agricultural drainage. In this study, we combine data from earth observing systems with auxiliary information on prices, yields, and farmer behavior in order to create a decision framework which assesses the public and private costs and benefits of distributed desalination in the Central Valley (CV) of California. The use of remotely sensed crop classifiers allows us to resolve our analysis at the 30m pixel scale across the CV, a feature that allows us to characterize regional differences in technology effectiveness. We employ environmental and economic modeling to estimate the value of lower salinity irrigation water; the value of augmented water supply under present and future climate scenarios; and the human health, environmental, and climate change damages associated with generating power to desalinate water. We find that water desalination is only likely to be profitable in 4% of the CV during periods of severe drought, and that current costs would need to decrease by 70-90% for adoption to occur on the median acre. Fossil-fuel powered desalination technologies also generate air emissions that impose significant public costs in the form of human health and climate change damages, although these damages vary greatly depending on technology. The ecosystem service benefits of reduced agricultural drainage would need to be valued between 800 and 1200 per acre-foot, or nearly the full capital and operational costs of water desalination, for the net benefits of water desalination to be positive from a societal perspective.

Theoretical modelling and optimization of bubble column dehumidifier for a solar driven humidification-dehumidification system

NASA Astrophysics Data System (ADS)

Ranjitha, P. Raj; Ratheesh, R.; Jayakumar, J. S.; Balakrishnan, Shankar

2018-02-01

Availability and utilization of energy and water are the top most global challenges being faced by the new millennium. At the present state water scarcity has become a global as well as a regional challenge. 40 % of world population faces water shortage. Challenge of water scarcity can be tackled only with increase in water supply beyond what is obtained from hydrological cycle. This can be achieved either by desalinating the sea water or by reusing the waste water. High energy requirement need to be overcome for either of the two processes. Of many desalination technologies, humidification dehumidification (HDH) technology powered by solar energy is widely accepted for small scale production. Detailed optimization studies on system have the potential to effectively utilize the solar energy for brackish water desalination. Dehumidification technology, specifically, require further study because the dehumidifier effectiveness control the energetic performance of the entire HDH system. The reason attributes to the high resistance involved to diffuse dilute vapor through air in a dehumidifier. The present work intends to optimize the design of a bubble column dehumidifier for a solar energy driven desalination process. Optimization is carried out using Matlab simulation. Design process will identify the unique needs of a bubble column dehumidifier in HDH system.

Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO).

PubMed

Sim, Victor S T; She, Qianhong; Chong, Tzyy Haur; Tang, Chuyang Y; Fane, Anthony G; Krantz, William B

2013-07-04

This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%-20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination.

Perspectives and Challenges for Water Desalination - A Socio-Economic Multi-Regional Analysis and a Case Study for Texas

NASA Astrophysics Data System (ADS)

Ziolkowska, J. R.; Scanlon, B. R.; Young, M.

2013-12-01

Water desalination is anticipated to become a prospective solution for mitigating future water shortages in Texas. As of 2010, 46 municipal brackish water desalination plants were operating in Texas with an estimated total desalination capacity of about 120 million gallons per day (2.3% of state water use) (TWDB 2010; TWDB 2013). In 2011, 99% of the State of Texas suffered extreme drought, with large portions suffering through exceptional drought. This event was classified as the one-year drought of record. Moreover, the growing population of Texas and the subsequent growing water demand create an immediate need for long-term planning for a reliable and efficient water supply. Desalination, even though acknowledged as a reliable option in many countries in the world, requires high investment costs and energy inputs. Current costs of desalinated water can range between US1.09/1,000 gallons and US3.7/1,000 gallons (Arroyo and Shirazi 2012), which are about two to three times higher than water costs from conventional sources (San Antonio Water System 2012; AustinTexas.gov 2013). Economic efficiency is still the main factor determining future developments of desalination investments in Texas, and the technology is still emerging. While currently only investment, maintenance and total capital costs per unit water are considered as factors determining viability of a desalination plant, this study aims at depicting a broader picture of socio-economic impacts related to the construction project itself, both in the immediate region and adjacent communities and interlinked sectors. This study presents an Input-Output model for the brackish water desalination plant in San Antonio, with the first stage expected to be completed in 2016. By using multi-regional and sectoral multipliers, the analysis shows that constructing the desalination plant can create 2,050 jobs in the San Antonio region, while it will add 316 more jobs in other regions in Texas by 2016. Construction will also create US133.9M of total added value in the San Antonio region and US36.6M in Texas. The total number of new jobs in the San Antonio region (3,718) and added value of US$262.8M is expected after completing the last construction phase in 2026. This study presents a broad picture of development patterns of desalination plants in Texas and the US, as well as future opportunities and challenges for this technology. It emphasizes the necessity of evaluating economic and social direct, indirect, and induced effects of desalination plants on a macro level, rather than focusing solely on the direct investment costs and costs of desalinated water provided to consumers.

Model-Based Extracted Water Desalination System for Carbon Sequestration

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

Dees, Elizabeth M.; Moore, David Roger; Li, Li

Over the last 1.5 years, GE Global Research and Pennsylvania State University defined a model-based, scalable, and multi-stage extracted water desalination system that yields clean water, concentrated brine, and, optionally, salt. The team explored saline brines that ranged across the expected range for extracted water for carbon sequestration reservoirs (40,000 up to 220,000 ppm total dissolved solids, TDS). In addition, the validated the system performance at pilot scale with field-sourced water using GE’s pre-pilot and lab facilities. This project encompassed four principal tasks, in addition to Project Management and Planning: 1) identify a deep saline formation carbon sequestration site andmore » a partner that are suitable for supplying extracted water; 2) conduct a techno-economic assessment and down-selection of pre-treatment and desalination technologies to identify a cost-effective system for extracted water recovery; 3) validate the downselected processes at the lab/pre-pilot scale; and 4) define the scope of the pilot desalination project. Highlights from each task are described below: Deep saline formation characterization The deep saline formations associated with the five DOE NETL 1260 Phase 1 projects were characterized with respect to their mineralogy and formation water composition. Sources of high TDS feed water other than extracted water were explored for high TDS desalination applications, including unconventional oil and gas and seawater reverse osmosis concentrate. Technoeconomic analysis of desalination technologies Techno-economic evaluations of alternate brine concentration technologies, including humidification-dehumidification (HDH), membrane distillation (MD), forward osmosis (FO), turboexpander-freeze, solvent extraction and high pressure reverse osmosis (HPRO), were conducted. These technologies were evaluated against conventional falling film-mechanical vapor recompression (FF-MVR) as a baseline desalination process. Furthermore, a quality function deployment (QFD) method was used to compare alternate high TDS desalination technologies to FF-MVR. High pressure reverse osmosis was found to a be a promising alternative desalination technology. A deep-dive technoeconomic analysis of HPRO was performed, including Capex and Opex estimates, for seawater RO (SWRO). Additionally, two additional cases were explored: 1) a comparison of a SWRO plus HPRO system to the option of doubling the size of a standard seawater RO system to achieve the same total pure water recovery rate; and 2) a flue gas desulfurization wastewater treatment zero-liquid discharge (ZLD) application, where preconcentration with RO (SWRO or SWRO + HPRO) before evaporation and crystallization was compared to FF-MVR and crystallization technologies without RO preconcentration. Pre-pilot process validation Pre-pilot-scale tests were conducted using field production water to validate key process steps for extracted water pretreatment. Approximately 5,000 gallons of field produced water was processed through, microfiltration, ultrafiltration, and steam regenerable sorbent operations. Smaller quantities were processed through microclarification. In addition, analytical methods (purge-and-trap gas chromatography and Hach TOC analytical methods) were validated. Lab-scale HPRO elements were constructed and tested at high pressures, to identify and mitigate technical risks of the technology. Lastly, improvements in RO membrane materials were identified as the necessary next step to achieve further improvement in element performance at high pressure. Scope of Field Pilot A field pilot for extracted water pretreatment was designed.« less

Microfluidic desalination techniques and their potential applications.

PubMed

Roelofs, S H; van den Berg, A; Odijk, M

2015-09-07

In this review we discuss recent developments in the emerging research field of miniaturized desalination. Traditionally desalination is performed to convert salt water into potable water and research is focused on improving performance of large-scale desalination plants. Microfluidic desalination offers several new opportunities in comparison to macro-scale desalination, such as providing a platform to increase fundamental knowledge of ion transport on the nano- and microfluidic scale and new microfluidic sample preparation methods. This approach has also lead to the development of new desalination techniques, based on micro/nanofluidic ion-transport phenomena, which are potential candidates for up-scaling to (portable) drinking water devices. This review assesses microfluidic desalination techniques on their applications and is meant to contribute to further implementation of microfluidic desalination techniques in the lab-on-chip community.

Flash memory management system and method utilizing multiple block list windows

NASA Technical Reports Server (NTRS)

Chow, James (Inventor); Gender, Thomas K. (Inventor)

2005-01-01

The present invention provides a flash memory management system and method with increased performance. The flash memory management system provides the ability to efficiently manage and allocate flash memory use in a way that improves reliability and longevity, while maintaining good performance levels. The flash memory management system includes a free block mechanism, a disk maintenance mechanism, and a bad block detection mechanism. The free block mechanism provides efficient sorting of free blocks to facilitate selecting low use blocks for writing. The disk maintenance mechanism provides for the ability to efficiently clean flash memory blocks during processor idle times. The bad block detection mechanism provides the ability to better detect when a block of flash memory is likely to go bad. The flash status mechanism stores information in fast access memory that describes the content and status of the data in the flash disk. The new bank detection mechanism provides the ability to automatically detect when new banks of flash memory are added to the system. Together, these mechanisms provide a flash memory management system that can improve the operational efficiency of systems that utilize flash memory.

Carbon nanotube membranes with ultrahigh specific adsorption capacity for water desalination and purification.

PubMed

Yang, Hui Ying; Han, Zhao Jun; Yu, Siu Fung; Pey, Kin Leong; Ostrikov, Kostya; Karnik, Rohit

2013-01-01

Development of technologies for water desalination and purification is critical to meet the global challenges of insufficient water supply and inadequate sanitation, especially for point-of-use applications. Conventional desalination methods are energy and operationally intensive, whereas adsorption-based techniques are simple and easy to use for point-of-use water purification, yet their capacity to remove salts is limited. Here we report that plasma-modified ultralong carbon nanotubes exhibit ultrahigh specific adsorption capacity for salt (exceeding 400% by weight) that is two orders of magnitude higher than that found in the current state-of-the-art activated carbon-based water treatment systems. We exploit this adsorption capacity in ultralong carbon nanotube-based membranes that can remove salt, as well as organic and metal contaminants. These ultralong carbon nanotube-based membranes may lead to next-generation rechargeable, point-of-use potable water purification appliances with superior desalination, disinfection and filtration properties.

Microbial desalination cell for enhanced biodegradation of waste engine oil using a novel bacterial strain Bacillus subtilis moh3.

PubMed

Sabina, K; Fayidh, Mohammed A; Archana, G; Sivarajan, M; Babuskin, S; Babu, P Azhagu Saravana; Radha, K Krishnan; Sukumar, M

2014-01-01

Microbial desalination cell (MDC) is a bioelectrochemical system developed recently from microbial fuel cells (MFCs), for producing green energy from organic wastes along with desalination of saltwater. MDC is proved to be a better performer than MFC in terms of power output and chemical oxygen demand removal, with desalination as an additional feature. This study investigates the application potential of MDC for integrated biodegradation of waste engine oil. This study showed, for the first time, that waste engine oil could be used as an organic substrate in MDC, achieving biodegradation of engine oil along with considerable desalination and power production. Utilization of these wastes in MDC can protect the environment from waste engine oil contamination. Indigenous oil-degrading bacteria were isolated and identified from engine oil contaminated sludge. Degradation of waste engine oil by these novel isolates was studied in batch cultures and optimized the growth conditions. The same cultures when used in MDC, gave enhanced biodegradation (70.1 +/- 0.5%) along with desalination (68.3 +/- 0.6%) and power production (3.1 +/- 0.3 mW/m2). Fourier transform-infrared spectroscopy and gas chromatography-mass spectrometry analyses were performed to characterize the degradation metabolites in the anolyte of MDC which clearly indicated the biodegradation of long chain, branched and cyclic hydrocarbons present in waste engine oil.

Modeling, control, and dynamic performance analysis of a reverse osmosis desalination plant integrated within hybrid energy systems

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

Kim, Jong Suk; Chen, Jun; Garcia, Humberto E.

An RO (reverse osmosis) desalination plant is proposed as an effective, FLR (flexible load resource) to be integrated into HES (hybrid energy systems) to support various types of ancillary services to the electric grid, under variable operating conditions. To study the dynamic (transient) analysis of such system, among the various unit operations within HES, special attention is given here to the detailed dynamic modeling and control design of RO desalination process with a spiral-wound membrane module. The model incorporates key physical phenomena that have been investigated individually into a dynamic integrated model framework. In particular, the solution-diffusion model modified withmore » the concentration polarization theory is applied to predict RO performance over a large range of operating conditions. Simulation results involving several case studies suggest that an RO desalination plant, acting as a FLR, can provide operational flexibility to participate in energy management at the utility scale by dynamically optimizing the use of excess electrical energy. Here, the incorporation of additional commodity (fresh water) produced from a FLR allows a broader range of HES operations for maximizing overall system performance and profitability. For the purpose of assessing the incorporation of health assessment into process operations, an online condition monitoring approach for RO membrane fouling supervision is addressed in the case study presented.« less

Modeling, control, and dynamic performance analysis of a reverse osmosis desalination plant integrated within hybrid energy systems

DOE PAGES

Kim, Jong Suk; Chen, Jun; Garcia, Humberto E.

2016-06-17

An RO (reverse osmosis) desalination plant is proposed as an effective, FLR (flexible load resource) to be integrated into HES (hybrid energy systems) to support various types of ancillary services to the electric grid, under variable operating conditions. To study the dynamic (transient) analysis of such system, among the various unit operations within HES, special attention is given here to the detailed dynamic modeling and control design of RO desalination process with a spiral-wound membrane module. The model incorporates key physical phenomena that have been investigated individually into a dynamic integrated model framework. In particular, the solution-diffusion model modified withmore » the concentration polarization theory is applied to predict RO performance over a large range of operating conditions. Simulation results involving several case studies suggest that an RO desalination plant, acting as a FLR, can provide operational flexibility to participate in energy management at the utility scale by dynamically optimizing the use of excess electrical energy. Here, the incorporation of additional commodity (fresh water) produced from a FLR allows a broader range of HES operations for maximizing overall system performance and profitability. For the purpose of assessing the incorporation of health assessment into process operations, an online condition monitoring approach for RO membrane fouling supervision is addressed in the case study presented.« less

ZVI (Fe0) desalination: catalytic partial desalination of saline aquifers

NASA Astrophysics Data System (ADS)

Antia, David D. J.

2018-05-01

Globally, salinization affects between 100 and 1000 billion m3 a-1 of irrigation water. The discovery that zero valent iron (ZVI, Fe0) could be used to desalinate water (using intra-particle catalysis in a diffusion environment) raises the possibility that large-scale in situ desalination of aquifers could be undertaken to support agriculture. ZVI desalination removes NaCl by an adsorption-desorption process in a multi-stage cross-coupled catalytic process. This study considers the potential application of two ZVI desalination catalyst types for in situ aquifer desalination. The feasibility of using ZVI catalysts when placed in situ within an aquifer to produce 100 m3 d-1 of partially desalinated water from a saline aquifer is considered.

Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO)

PubMed Central

Sim, Victor S.T.; She, Qianhong; Chong, Tzyy Haur; Tang, Chuyang Y.; Fane, Anthony G.; Krantz, William B.

2013-01-01

This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%–20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination. PMID:24956940

Use of Low-Temperature Geothermal Energy for Desalination in the Western United States

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

Turchi, Craig S.; Akar, Sertac; Cath, Tzahi

2015-11-01

This joint project between the National Renewable Energy Laboratory and the Colorado School of Mines has examined the potential of using low-temperature geothermal resources for desalination. The temperature range in question is not well suited for electricity generation, but can be used for direct heating. Accordingly, the best integration approaches use thermal desalination technologies such as multi-effect distillation (MED) or membrane distillation (MD), rather than electric-driven technologies such as reverse osmosis (RO). The examination of different desalination technologies led to the selection of MD for pairing with geothermal energy. MD operates at near-ambient pressure and temperatures less than 100°C withmore » hydrophobic membranes. The technology is modular like RO, but the equipment costs are lower. The thermal energy demands of MD are higher than MED, but this is offset by an ability to run at lower temperatures and a low capital cost. Consequently, a geothermal-MD system could offer a low capital cost and, if paired with low-cost geothermal energy, a low operating cost. The target product water cost is $1.0 to $1.5 per cubic meter depending on system capacity and the cost of thermal energy.« less

Adaptive P300 based control system

PubMed Central

Jin, Jing; Allison, Brendan Z.; Sellers, Eric W.; Brunner, Clemens; Horki, Petar; Wang, Xingyu; Neuper, Christa

2015-01-01

An adaptive P300 brain-computer interface (BCI) using a 12 × 7 matrix explored new paradigms to improve bit rate and accuracy. During online use, the system adaptively selects the number of flashes to average. Five different flash patterns were tested. The 19-flash paradigm represents the typical row/column presentation (i.e., 12 columns and 7 rows). The 9- and 14-flash A & B paradigms present all items of the 12 × 7 matrix three times using either nine or 14 flashes (instead of 19), decreasing the amount of time to present stimuli. Compared to 9-flash A, 9-flash B decreased the likelihood that neighboring items would flash when the target was not flashing, thereby reducing interference from items adjacent to targets. 14-flash A also reduced adjacent item interference and 14-flash B additionally eliminated successive (double) flashes of the same item. Results showed that accuracy and bit rate of the adaptive system were higher than the non-adaptive system. In addition, 9- and 14-flash B produced significantly higher performance than their respective A conditions. The results also show the trend that the 14-flash B paradigm was better than the 19-flash pattern for naïve users. PMID:21474877

Impact of socio-economic growth on desalination in the US.

PubMed

Ziolkowska, Jadwiga R; Reyes, Reuben

2016-02-01

In 2013, around 1336 desalination plants in the United States (US) provided purified water mainly to municipalities, the industry sector and for power generation. In 2013 alone, ∼200 million m(3) of water were desalinated; the amount that could satisfy annual municipal water consumption of more than 1.5 million people in the US. Desalination has proven to be a reliable water supply source in many countries around the world, with the total global desalination capacity of ∼60 million m(3)/day in 2013. Desalination has been used to mitigate water scarcity and lessen the pressure on water resources. Currently, data and information about desalination are still limited, while extensive socio-economic analyses are missing. This paper presents an econometric model to fill this gap. It evaluates the impact of selected socio-economic variables on desalination development in the US in the time span 1970-2013. The results show that the GDP and population growth have significantly impacted the desalination sector over the analyzed time period. The insights into the economics of desalination provided with this paper can be used to further evaluate cost-effectiveness of desalination both in the US and in other countries around the world. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microbial desalination cells packed with ion-exchange resin to enhance water desalination rate.

PubMed

Morel, Alexandre; Zuo, Kuichang; Xia, Xue; Wei, Jincheng; Luo, Xi; Liang, Peng; Huang, Xia

2012-08-01

A novel configuration of microbial desalination cell (MDC) packed with ion-exchange resin (R-MDC) was proposed to enhance water desalination rate. Compared with classic MDC (C-MDC), an obvious increase in desalination rate (DR) was obtained by R-MDC. With relatively low concentration (10-2 g/L NaCl) influents, the DR values of R-MDC were about 1.5-8 times those of C-MDC. Ion-exchange resins packed in the desalination chamber worked as conductor and thus counteracted the increase in ohmic resistance during treatment of low concentration salt water. Ohmic resistances of R-MDC stabilized at 3.0-4.7 Ω. By contrast, the ohmic resistances of C-MDC ranged from 5.5 to 12.7 Ω, which were 55-272% higher than those of R-MDC. Remarkable improvement in desalination rate helped improve charge efficiency for desalination in R-MDC. The results first showed the potential of R-MDC in the desalination of water with low salinity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Optimizing desalinated sea water blending with other sources to meet magnesium requirements for potable and irrigation waters.

PubMed

Avni, Noa; Eben-Chaime, Moshe; Oron, Gideon

2013-05-01

Sea water desalination provides fresh water that typically lacks minerals essential to human health and to agricultural productivity. Thus the rising proportion of desalinated sea water consumed by both the domestic and agricultural sectors constitutes a public health risk. Research on low-magnesium water irrigation showed that crops developed magnesium deficiency symptoms that could lead to plant death, and tomato yields were reduced by 10-15%. The World Health Organization (WHO) reported on a relationship between sudden cardiac death rates and magnesium intake deficits. An optimization model, developed and tested to provide recommendations for Water Distribution System (WDS) quality control in terms of meeting optimal water quality requirements, was run in computational experiments based on an actual regional WDS. The expected magnesium deficit due to the operation of a large Sea Water Desalination Plant (SWDP) was simulated, and an optimal operation policy, in which remineralization at the SWDP was combined with blending desalinated and natural water to achieve the required quality, was generated. The effects of remineralization costs and WDS physical layout on the optimal policy were examined by sensitivity analysis. As part of the sensitivity blending natural and desalinated water near the treatment plants will be feasible up to 16.2 US cents/m(3), considering all expenses. Additional chemical injection was used to meet quality criteria when blending was not feasible. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

A prototype for communitising technology: Development of a smart salt water desalination device

NASA Astrophysics Data System (ADS)

Fakharuddin, F. M.; Fatchurrohman, N.; Puteh, S.; Puteri, H. M. A. R.

2018-04-01

Desalination is defined as the process that removes minerals from saline water or commonly known as salt water. Seawater desalination is becoming an attractive source of drinking water in coastal states as the costs for desalination declines. The purpose of this study is to develop a small scale desalination device and able to do an analysis of the process flow by using suitable sensors. Thermal technology was used to aid the desalination process. A graphical user interface (GUI) for the interface was made to enable the real time data analysis of the desalination device. ArduinoTM microcontroller was used in this device in order to develop an automatic device.

Drivers of an urban community's acceptance of a large desalination scheme for drinking water

NASA Astrophysics Data System (ADS)

Gibson, Fiona L.; Tapsuwan, Sorada; Walker, Iain; Randrema, Elodie

2015-09-01

Changing climates and growing populations have prompted policy makers to shift to more climate resilient, technology-driven water sources, such as seawater desalination. Desalination is a prominent water resource in the Middle East but countries in other parts of the world with similar scarcity issues and good access to sea water, such as Australia, have been comparatively slow to adopt it. This paper explores attitudes to desalination in Perth, Western Australia, and the factors that influence its acceptance. We compared individuals' acceptance of desalination over two time periods by using identical surveys administered in 2007 and 2012. We then examined the attitudinal factors - attitudes towards desalination and attitudes towards the environment - that influence acceptance. Acceptance of desalination was reasonably high and stable at both times (74% and 73% in 2007 and 2012 respectively). We found that respondents' attitudes to perceived outcomes and benefits, fairness, environmental obligation and risk were important predictors of their acceptance of desalination in both surveys. However the weight given to these aspects varied over time. The findings show that there is still mixed community sentiment towards desalination, which helps to explain why acceptance has not increased since desalination was introduced in 2006.

Hold-up power supply for flash memory

NASA Technical Reports Server (NTRS)

Ott, William E. (Inventor)

2004-01-01

A hold-up power supply for flash memory systems is provided. The hold-up power supply provides the flash memory with the power needed to temporarily operate when a power loss exists. This allows the flash memory system to complete any erasures and writes, and thus allows it to shut down gracefully. The hold-up power supply detects when a power loss on a power supply bus is occurring and supplies the power needed for the flash memory system to temporally operate. The hold-up power supply stores power in at least one capacitor. During normal operation, power from a high voltage supply bus is used to charge the storage capacitors. When a power supply loss is detected, the power supply bus is disconnected from the flash memory system. A hold-up controller controls the power flow from the storage capacitors to the flash memory system. The hold-up controller uses feedback to assure that the proper voltage is provided from the storage capacitors to the flash memory system. This power supplied by the storage capacitors allows the flash memory system to complete any erasures and writes, and thus allows the flash memory system to shut down gracefully.

Hierarchical distance-based fuzzy approach to evaluate urban water supply systems in a semi-arid region.

PubMed

Yekta, Tahereh Sadeghi; Khazaei, Mohammad; Nabizadeh, Ramin; Mahvi, Amir Hossein; Nasseri, Simin; Yari, Ahmad Reza

2015-01-01

Hierarchical distance-based fuzzy multi-criteria group decision making was served as a tool to evaluate the drinking water supply systems of Qom, a semi-arid city located in central part of Iran. A list of aspects consisting of 6 criteria and 35 sub-criteria were evaluated based on a linguistic term set by five decision-makers. Four water supply alternatives including "Public desalinated distribution system", "PET Bottled Drinking Water", "Private desalinated water suppliers" and "Household desalinated water units" were assessed based on criteria and sub-criteria. Data were aggregated and normalized to apply Performance Ratings of Alternatives. Also, the Performance Ratings of Alternatives were aggregated again to achieve the Aggregate Performance Ratings. The weighted distances from ideal solution and anti-ideal solution were calculated after secondary normalization. The proximity of each alternative to the ideal solution was determined as the final step. The alternatives were ranked based on the magnitude of ideal solutions. Results showed that "Public desalinated distribution system" was the most appropriate alternative to supply the drinking needs of Qom population. Also, "PET Bottled Drinking Water" was the second acceptable option. A novel classification of alternatives to satisfy the drinking water requirements was proposed which is applicable for the other cities located in semi-arid regions of Iran. The health issues were considered as independent criterion, distinct from the environmental issues. The constraints of high-tech alternatives were also considered regarding to the level of dependency on overseas.

Membraneless seawater desalination

DOEpatents

Crooks, Richard A.; Knust, Kyle N.; Perdue, Robbyn K.

2018-04-03

Disclosed are microfluidic devices and systems for the desalination of water. The devices and systems can include an electrode configured to generate an electric field gradient in proximity to an intersection formed by the divergence of two microfluidic channels from an inlet channel. Under an applied bias and in the presence of a pressure driven flow of saltwater, the electric field gradient can preferentially direct ions in saltwater into one of the diverging microfluidic channels, while desalted water flows into second diverging channel. Also provided are methods of using the devices and systems described herein to decrease the salinity of water.

Life cycle analysis of distributed concentrating solar combined heat and power: economics, global warming potential and water

NASA Astrophysics Data System (ADS)

Norwood, Zack; Kammen, Daniel

2012-12-01

We report on life cycle assessment (LCA) of the economics, global warming potential and water (both for desalination and water use in operation) for a distributed concentrating solar combined heat and power (DCS-CHP) system. Detailed simulation of system performance across 1020 sites in the US combined with a sensible cost allocation scheme informs this LCA. We forecast a levelized cost of 0.25 kWh-1 electricity and 0.03 kWh-1 thermal, for a system with a life cycle global warming potential of ˜80 gCO2eq kWh-1 of electricity and ˜10 gCO2eq kWh-1 thermal, sited in Oakland, California. On the basis of the economics shown for air cooling, and the fact that any combined heat and power system reduces the need for cooling while at the same time boosting the overall solar efficiency of the system, DCS-CHP compares favorably to other electric power generation systems in terms of minimization of water use in the maintenance and operation of the plant. The outlook for water desalination coupled with distributed concentrating solar combined heat and power is less favorable. At a projected cost of 1.40 m-3, water desalination with DCS-CHP would be economical and practical only in areas where water is very scarce or moderately expensive, primarily available through the informal sector, and where contaminated or salt water is easily available as feed-water. It is also interesting to note that 0.40-1.90 m-3 is the range of water prices in the developed world, so DCS-CHP desalination systems could also be an economical solution there under some conditions.

Application of forward osmosis membrane technology for oil sands process-affected water desalination.

PubMed

Jiang, Yaxin; Liang, Jiaming; Liu, Yang

2016-01-01

The extraction process used to obtain bitumen from the oil sands produces large volumes of oil sands process-affected water (OSPW). As a newly emerging desalination technology, forward osmosis (FO) has shown great promise in saving electrical power requirements, increasing water recovery, and minimizing brine discharge. With the support of this funding, a FO system was constructed using a cellulose triacetate FO membrane to test the feasibility of OSPW desalination and contaminant removal. The FO systems were optimized using different types and concentrations of draw solution. The FO system using 4 M NH4HCO3 as a draw solution achieved 85% water recovery from OSPW, and 80 to 100% contaminant rejection for most metals and ions. A water backwash cleaning method was applied to clean the fouled membrane, and the cleaned membrane achieved 77% water recovery, a performance comparable to that of new FO membranes. This suggests that the membrane fouling was reversible. The FO system developed in this project provides a novel and energy efficient strategy to remediate the tailings waters generated by oil sands bitumen extraction and processing.

Advanced Control Synthesis for Reverse Osmosis Water Desalination Processes.

PubMed

Phuc, Bui Duc Hong; You, Sam-Sang; Choi, Hyeung-Six; Jeong, Seok-Kwon

2017-11-01

  In this study, robust control synthesis has been applied to a reverse osmosis desalination plant whose product water flow and salinity are chosen as two controlled variables. The reverse osmosis process has been selected to study since it typically uses less energy than thermal distillation. The aim of the robust design is to overcome the limitation of classical controllers in dealing with large parametric uncertainties, external disturbances, sensor noises, and unmodeled process dynamics. The analyzed desalination process is modeled as a multi-input multi-output (MIMO) system with varying parameters. The control system is decoupled using a feed forward decoupling method to reduce the interactions between control channels. Both nominal and perturbed reverse osmosis systems have been analyzed using structured singular values for their stabilities and performances. Simulation results show that the system responses meet all the control requirements against various uncertainties. Finally the reduced order controller provides excellent robust performance, with achieving decoupling, disturbance attenuation, and noise rejection. It can help to reduce the membrane cleanings, increase the robustness against uncertainties, and lower the energy consumption for process monitoring.

Coupling Power Generation, Geologic CO2 Storage and Saline Groundwater Desalination to Address Growing Energy Needs in Water Constrained Regions

NASA Astrophysics Data System (ADS)

Davidson, C. L.; Wurstner, S. K.; Fortson, L. A.

2010-12-01

As humanity works to both minimize climate change and adapt to its early impacts, co-management of energy and water resources will become increasingly important. In some parts of the US, power plants have been denied permits, in part because of the significant burden placed on local water supplies by assigning new water rights for the facility’s entire design life. Water resources may be allocated 30 to 50 years into a future where water availability and quality are uncertain due to supply impacts associated with climate change and increased demand from growing populations, agriculture and industry. In many areas, particularly those with access to seawater, desalination is being employed with increasing frequency to augment conventional sources of fresh water. At the same time, many of the world’s developed nations are moving to reduce greenhouse gas emissions. One key technological option for addressing emissions from the power generation sector is CO2 capture and geologic storage (CCS). This process is both water and energy intensive for many power and industrial facilities, compounding the impact of declining water availability for plants faced with deploying CCS in a CO2-constrained future. However, a unique opportunity may exist to couple power generation and CCS by extracting and desalinating brine from the CO2 storage formation to produce fresh water. While this coupled approach is unlikely to be attractive for most CCS projects, it may represent a viable option in areas where there is demand for additional electricity but conventional water supplies are unable to meet the needs of the power generation and CO2 capture systems, or in areas where brine produced from CCS projects can be desalinated to supplement strained municipal supplies. This paper presents a preliminary analysis of the factors impacting the feasibility of coupled CCS-desalination projects. Several injection / extraction scenarios have been examined via the STOMP geochemical flow model resulting in key outputs including extraction wellhead conditions, in situ CO2 plume behavior and reservoir pressure. Economic modeling for the water extraction and desalination portion of these coupled CCS / desalination scenarios suggests that -- while some scenarios yield costs far in excess of most existing desalination projects -- depending on the specific storage formation characteristics and desalination technology employed, fresh water could be produced at costs competitive with seawater desalination facilities, bolstering local water supplies and enabling deployment of industrial projects that might otherwise have been infeasible.

Toward Future Photovoltaic-Based Agriculture in Sea.

PubMed

Moustafa, Khaled

2016-04-01

To meet the challenges of climate change and water shortages, combining solar energy-based seawater desalination technologies with floating agriculture stations in one innovative hybrid system would be worthy of investigation for dry and sunny regions for seawater desalination and crop production within the same platform. Here, I discuss the feasibility of such a 'floating farm' or 'bluehouse' in the sea, by comparing it with the use of terrestrial greenhouses. I also debate the potential advantages and shortcomings of such a system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimental Analysis of Desalination Unit Coupled with Solar Water Lens Concentrator

NASA Astrophysics Data System (ADS)

Chaithanya, K. K.; Rajesh, V. R.; Suresh, Rahul

2016-09-01

The main problem that the world faces in this scenario is shortage of potable water. Hence this research work rivets to increase the yield of desalination system in an economical way. The integration of solar concentrator and desalination unit can project the desired yield, but the commercially available concentrated solar power technologies (CSP) are not economically viable. So this study proposes a novel method to concentrate ample amount of solar radiation in a cost effective way. Water acting as lens is a highlighted technology initiated in this work, which can be a substitute for CSP systems. And water lens can accelerate the desalination process so as to increase the yield economically. The solar irradiance passing through the water will be concentrated at a focal point, and the concentration depends on curvature of water lens. The experimental analysis of water lens makes use of transparent thin sheet, supported on a metallic structure. The Plano convex shape of water lens is developed by varying the volume of water that is being poured on the transparent thin sheet. From the experimental analysis it is inferred that, as the curvature of water lens increases, solar irradiance can be focused more accurately on to the focus and a higher water temperature is obtained inside the solar still.

A conceptual demonstration of freeze desalination-membrane distillation (FD-MD) hybrid desalination process utilizing liquefied natural gas (LNG) cold energy.

PubMed

Wang, Peng; Chung, Tai-Shung

2012-09-01

The severe global water scarcity and record-high fossil oil price have greatly stimulated the research interests on new desalination technologies which can be driven by renewable energy or waste energy. In this study, a hybrid desalination process comprising freeze desalination and membrane distillation (FD-MD) processes was developed and explored in an attempt to utilize the waste cold energy released from re-gasification of liquefied natural gas (LNG). The concept of this technology was demonstrated using indirect-contact freeze desalination (ICFD) and direct-contact membrane distillation (DCMD) configurations. By optimizing the ICFD operation parameters, namely, the usage of nucleate seeds, operation duration and feed concentration, high quality drinkable water with a low salinity ∼0.144 g/L was produced in the ICFD process. At the same time, using the optimized hollow fiber module length and packing density in the DCMD process, ultra pure water with a low salinity of 0.062 g/L was attained at a condition of high energy efficiency (EE). Overall, by combining FD and MD processes and adopting the optimized operation parameters, the hybrid FD-MD system has been successfully demonstrated. A high total water recovery of 71.5% was achieved, and the water quality obtained met the standard for drinkable water. In addition, with results from specific energy calculation, it was proven that the hybrid process is an energy-saving process and utilization of LNG cold energy could greatly reduce the total energy consumption. Copyright © 2012 Elsevier Ltd. All rights reserved.

Use of geothermal energy for desalination in New Mexico: a feasibility study. Final report, January 1, 1977-May 30, 1979

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

Chaturvedi, L.; Keyes, C.G. Jr.; Swanberg, C.A.

The water requirements and availability for New Mexico are described. The possibility of using geothermal resources for desalination of the state's saline water sources is discussed. The following aspects of the problem are covered: resource evaluation, geothermal desalination technology, potential geothermal desalination sites, saline and geothermal aquifer well fields design, geothermal desalination plant waste brine disposal, process water pumping and brine disposal unit costs, environmental considerations, and legal and institutional considerations. (MHR)

Force Projection Technology Overview

DTIC Science & Technology

2011-08-12

Technologies • Fuel Efficient Powertrain Lubricant • Nanotechnology for Fuels and Lubes • Water from Air • Water Reuse • In-line Water Monitoring...purification systems with new pretreatment, desalination and post treatment technologies. Payoff: • Reduces the logistical footprint associated with water...FY11 FY12 FY13 FY14 FY15 FY16 FY17 •Water From Air •Water Quality Monitoring •Water Reuse •Pre and Post Treatment • Desalination 6 5 5

Modeling Remineralization of Desalinated Water by Micronized Calcite Dissolution.

PubMed

Hasson, David; Fine, Larissa; Sagiv, Abraham; Semiat, Raphael; Shemer, Hilla

2017-11-07

A widely used process for remineralization of desalinated water consists of dissolution of calcite particles by flow of acidified desalinated water through a bed packed with millimeter-size calcite particles. An alternative process consists of calcite dissolution by slurry flow of micron-size calcite particles with acidified desalinated water. The objective of this investigation is to provide theoretical models enabling design of remineralization by calcite slurry dissolution with carbonic and sulfuric acids. Extensive experimental results are presented displaying the effects of acid concentration, slurry feed concentration, and dissolution contact time. The experimental data are shown to be in agreement within less than 10% with theoretical predictions based on the simplifying assumption that the slurry consists of uniform particles represented by the surface mean diameter of the powder. Agreement between theory and experiment is improved by 1-8% by taking into account the powder size distribution. Apart from the practical value of this work in providing a hitherto lacking design tool for a novel technology. The paper has the merit of being among the very few publications providing experimental confirmation to the theory describing reaction kinetics in a segregated flow system.

A ten liter stacked microbial desalination cell packed with mixed ion-exchange resins for secondary effluent desalination.

PubMed

Zuo, Kuichang; Cai, Jiaxiang; Liang, Shuai; Wu, Shijia; Zhang, Changyong; Liang, Peng; Huang, Xia

2014-08-19

The architecture and performance of microbial desalination cell (MDC) have been significantly improved in the past few years. However, the application of MDC is still limited in a scope of small-scale (milliliter) reactors and high-salinity-water desalination. In this study, a large-scale (>10 L) stacked MDC packed with mixed ion-exchange resins was fabricated and operated in the batch mode with a salt concentration of 0.5 g/L NaCl, a typical level of domestic wastewater. With circulation flow rate of 80 mL/min, the stacked resin-packed MDC (SR-MDC) achieved a desalination efficiency of 95.8% and a final effluent concentration of 0.02 g/L in 12 h, which is comparable with the effluent quality of reverse osmosis in terms of salinity. Moreover, the SR-MDC kept a stable desalination performance (>93%) when concentrate volume decreased from 2.4 to 0.1 L (diluate/concentrate volume ratio increased from 1:1 to 1:0.04), where only 0.875 L of nonfresh water was consumed to desalinate 1 L of saline water. In addition, the SR-MDC achieved a considerable desalination rate (95.4 mg/h), suggesting a promising application for secondary effluent desalination through deriving biochemical electricity from wastewater.

Desalination: Status and Federal Issues

DTIC Science & Technology

2009-12-30

on one side and lets purified water through. Reverse osmosis plants have fewer problems with corrosion and usually have lower energy requirements...Texas) and cities are actively researching and investigating the feasibility of large-scale desalination plants for municipal water supplies...desalination research and development, and in construction and operational costs of desalination demonstration projects and full-scale plants

Integrated processes for desalination and salt production: A mini-review

NASA Astrophysics Data System (ADS)

Wenten, I. Gede; Ariono, Danu; Purwasasmita, Mubiar; Khoirudin

2017-03-01

The scarcity of fresh water due to the rapid growth of population and industrial activities has increased attention on desalination process as an alternative freshwater supply. In desalination process, a large volume of saline water is treated to produce freshwater while a concentrated brine is discharged back into the environment. The concentrated brine contains a high concentration of salt and also chemicals used during desalination operations. Due to environmental impacts arising from improper treatment of the brine and more rigorous regulations of the pollution control, many efforts have been devoted to minimize, treat, or reuse the rejected brine. One of the most promising alternatives for brine handling is reusing the brine which can reduce pollution, minimize waste volume, and recover valuable salt. Integration of desalination and salt production can be implemented to reuse the brine by recovering water and the valuable salts. The integrated processes can achieve zero liquid discharge, increase water recovery, and produce the profitable salt which can reduce the overall desalination cost. This paper gives an overview of desalination processes and the brine impacts. The integrated processes, including their progress and advantages in dual-purpose desalination and salt production are discussed.

Effects of blending of desalinated water with treated surface drinking water on copper and lead release.

PubMed

Liu, Haizhou; Schonberger, Kenneth D; Korshin, Gregory V; Ferguson, John F; Meyerhofer, Paul; Desormeaux, Erik; Luckenbach, Heidi

2010-07-01

This study examined effects of desalinated water on the corrosion of and metal release from copper and lead-containing materials. A jar test protocol was employed to examine metal release from copper and lead-tin coupons exposed to water chemistries with varying blending ratios of desalinated water, alkalinities, pHs and orthophosphate levels. Increasing fractions of desalinated water in the blends resulted in non-monotonic changes of copper and lead release, with generally lower metal concentrations in the presence of desalinated water, especially when its contribution increased from 80% to 100%. SEM examination showed that the increased fractions of desalinated water were associated with pronounced changes of the morphology of the corrosion scales, likely due to the influence of natural organic matter. This hypothesis was corroborated by the existence of correlations between changes of the zeta-potential of representative minerals (malachite and hydrocerussite) and metal release. For practical applications, maintaining pH at 7.8 and adding 1 mg/L orthophosphate as PO(4) were concluded to be adequate to decrease copper and lead release. Lower alkalinity of desalinated water was beneficial for blends containing 50% or more desalinated water. Copyright 2010 Elsevier Ltd. All rights reserved.

Effects of blending of desalinated and conventionally treated surface water on iron corrosion and its release from corroding surfaces and pre-existing scales.

PubMed

Liu, Haizhou; Schonberger, Kenneth D; Peng, Ching-Yu; Ferguson, John F; Desormeaux, Erik; Meyerhofer, Paul; Luckenbach, Heidi; Korshin, Gregory V

2013-07-01

This study examined effects of blending desalinated water with conventionally treated surface water on iron corrosion and release from corroding metal surfaces and pre-existing scales exposed to waters having varying fractions of desalinated water, alkalinities, pH values and orthophosphate levels. The presence of desalinated water resulted in markedly decreased 0.45 μm-filtered soluble iron concentrations. However, higher fractions of desalinated water in the blends were also associated with more fragile corroding surfaces, lower retention of iron oxidation products and release of larger iron particles in the bulk water. SEM, XRD and XANES data showed that in surface water, a dense layer of amorphous ferrihydrite phase predominated in the corrosion products. More crystalline surface phases developed in the presence of desalinated water. These solid phases transformed from goethite to lepidocrocite with increased fraction of desalinated water. These effects are likely to result from a combination of chemical parameters, notably variations of the concentrations of natural organic matter, calcium, chloride and sulfate when desalinated and conventionally treated waters are blended. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhancing forward osmosis water recovery from landfill leachate by desalinating brine and recovering ammonia in a microbial desalination cell.

PubMed

Iskander, Syeed Md; Novak, John T; He, Zhen

2018-05-01

In this work, a microbial desalination cell (MDC) was employed to desalinate the FO treated leachate for reduction of both salinity and chemical oxygen demand (COD). The FO recovered 51.5% water from a raw leachate and the recovery increased to 83.5% from the concentrated leachate after desalination in the MDC fed with either acetate or another leachate as an electron source and at a different hydraulic retention time (HRT). Easily-degraded substrate like acetate and a long HRT resulted in a low conductivity desalinated effluent. Ammonia was also recovered in the MDC cathode with a recovery efficiency varying from 11 to 64%, affected by current generation and HRT. Significant COD reduction, as high as 65.4%, was observed in the desalination chamber and attributed to the decrease of both organic and inorganic compounds via diffusion and electricity-driven movement. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bacteriological assessment of urban water sources in Khamis Mushait Governorate, southwestern Saudi Arabia.

PubMed

AlOtaibi, Eed L Sh

2009-03-21

Urban water sources of Khamis Mushait Governorate, southwestern Saudi Arabia, were studied to assess their bacteriological characteristics and suitability for potable purposes. A cross-sectional epidemiological method was adopted to investigate the four main urban water sources (i.e. bottled, desalinated, surface, and well water). These were sampled and examined between February and June 2007. A total of 95 water samples from bottled, desalinated, surface, and well water were collected randomly from the study area using different gathering and analysing techniques. The bacteriological examination of water samples included the most probable number of presumptive coliforms, faecal coliforms, and faecal streptococci (MPN/100 ml). The results showed that the total coliform count (MPN/100 ml) was not detected in any samples taken from bottled water, while it was detected in those taken from desalinated, surface, and well water: percentages were 12.9, 80.0, and 100.0, respectively. Faecal coliforms were detected in desalinated, surface, and well water, with percentages of 3.23, 60.0 and 87.88, respectively. About 6.45% of desalinated water, 53.33% of surface water, and 57.58% of well water was found positive for faecal streptococci. Colonies of coliforms were identified in different micro-organisms with various percentages. Water derived from traditional sources (wells) showed increases in most of the investigated bacteriological parameters, followed by surface water as compared to bottled or desalinated water. This may be attributed to the fact that well and surface water are at risk of contamination as indicated by the higher levels of most bacteriological parameters. Moreover, well water is exposed to point sources of pollution such as septic wells and domestic and farming effluents, as well as to soil with a high humus content. The lower bacteriological characteristics in samples from bottled water indicate that it is satisfactory for human drinking purposes. Contamination of desalinated water that is the main urban water source may occur during transportation from the desalination plant or in the house reservoir of the consumer. Improving and expanding the existing water treatment and sanitation systems is more likely to provide safe and sustainable sources of water over the long term. Strict hygienic measures should be applied to improve water quality and to avoid deleterious effects on public health, by using periodical monitoring programmes to detect sewage pollution running over local hydrological networks and valleys.

Bacteriological assessment of urban water sources in Khamis Mushait Governorate, southwestern Saudi Arabia

PubMed Central

Sh AlOtaibi, Eed L

2009-01-01

Background Urban water sources of Khamis Mushait Governorate, southwestern Saudi Arabia, were studied to assess their bacteriological characteristics and suitability for potable purposes. A cross-sectional epidemiological method was adopted to investigate the four main urban water sources (i.e. bottled, desalinated, surface, and well water). These were sampled and examined between February and June 2007. Results A total of 95 water samples from bottled, desalinated, surface, and well water were collected randomly from the study area using different gathering and analysing techniques. The bacteriological examination of water samples included the most probable number of presumptive coliforms, faecal coliforms, and faecal streptococci (MPN/100 ml). The results showed that the total coliform count (MPN/100 ml) was not detected in any samples taken from bottled water, while it was detected in those taken from desalinated, surface, and well water: percentages were 12.9, 80.0, and 100.0, respectively. Faecal coliforms were detected in desalinated, surface, and well water, with percentages of 3.23, 60.0 and 87.88, respectively. About 6.45% of desalinated water, 53.33% of surface water, and 57.58% of well water was found positive for faecal streptococci. Colonies of coliforms were identified in different micro-organisms with various percentages. Conclusion Water derived from traditional sources (wells) showed increases in most of the investigated bacteriological parameters, followed by surface water as compared to bottled or desalinated water. This may be attributed to the fact that well and surface water are at risk of contamination as indicated by the higher levels of most bacteriological parameters. Moreover, well water is exposed to point sources of pollution such as septic wells and domestic and farming effluents, as well as to soil with a high humus content. The lower bacteriological characteristics in samples from bottled water indicate that it is satisfactory for human drinking purposes. Contamination of desalinated water that is the main urban water source may occur during transportation from the desalination plant or in the house reservoir of the consumer. Improving and expanding the existing water treatment and sanitation systems is more likely to provide safe and sustainable sources of water over the long term. Strict hygienic measures should be applied to improve water quality and to avoid deleterious effects on public health, by using periodical monitoring programmes to detect sewage pollution running over local hydrological networks and valleys. PMID:19302710

A new method for water desalination using microbial desalination cells.

PubMed

Cao, Xiaoxin; Huang, Xia; Liang, Peng; Xiao, Kang; Zhou, Yingjun; Zhang, Xiaoyuan; Logan, Bruce E

2009-09-15

Current water desalination techniques are energy intensive and some use membranes operated at high pressures. It is shown here that water desalination can be accomplished without electrical energy input or high water pressure by using a source of organic matter as the fuel to desalinate water. A microbial fuel cell was modified by placing two membranes between the anode and cathode, creating a middle chamber for water desalination between the membranes. An anion exchange membrane was placed adjacent to the anode, and a cation exchange membrane was positioned next to the cathode. When current was produced by bacteria on the anode, ionic species in the middle chamber were transferred into the two electrode chambers, desalinating the water in the middle chamber. Proof-of-concept experiments for this approach, using what we call a microbial desalination cell (MDC), was demonstrated using water at different initial salt concentrations (5, 20, and 35 g/L) with acetate used as the substrate for the bacteria. The MDC produced a maximum of 2 W/m2 (31 W/m3) while at the same time removing about 90% of the salt in a single desalination cycle. As the salt was removed from the middle chamber the ohmic resistance of the MDC (measured using electrochemical impedance spectroscopy) increased from 25 Omega to 970 Omega at the end of the cycle. This increased resistance was reflected by a continuous decrease in the voltage produced over the cycle. These results demonstrate for the first time the possibility for a new method for water desalination and power production that uses only a source of biodegradable organic matter and bacteria.

Desalination and reuse of high-salinity shale gas produced water: drivers, technologies, and future directions.

PubMed

Shaffer, Devin L; Arias Chavez, Laura H; Ben-Sasson, Moshe; Romero-Vargas Castrillón, Santiago; Yip, Ngai Yin; Elimelech, Menachem

2013-09-03

In the rapidly developing shale gas industry, managing produced water is a major challenge for maintaining the profitability of shale gas extraction while protecting public health and the environment. We review the current state of practice for produced water management across the United States and discuss the interrelated regulatory, infrastructure, and economic drivers for produced water reuse. Within this framework, we examine the Marcellus shale play, a region in the eastern United States where produced water is currently reused without desalination. In the Marcellus region, and in other shale plays worldwide with similar constraints, contraction of current reuse opportunities within the shale gas industry and growing restrictions on produced water disposal will provide strong incentives for produced water desalination for reuse outside the industry. The most challenging scenarios for the selection of desalination for reuse over other management strategies will be those involving high-salinity produced water, which must be desalinated with thermal separation processes. We explore desalination technologies for treatment of high-salinity shale gas produced water, and we critically review mechanical vapor compression (MVC), membrane distillation (MD), and forward osmosis (FO) as the technologies best suited for desalination of high-salinity produced water for reuse outside the shale gas industry. The advantages and challenges of applying MVC, MD, and FO technologies to produced water desalination are discussed, and directions for future research and development are identified. We find that desalination for reuse of produced water is technically feasible and can be economically relevant. However, because produced water management is primarily an economic decision, expanding desalination for reuse is dependent on process and material improvements to reduce capital and operating costs.

Phased charging and discharging in capacitive desalinatio

DOEpatents

Stadermann, Michael; Qu, Yatian; Santiago, Juan G.; Hemmatifar, Ali

2017-09-12

A system combines complete, ultra-thin cells into a monolithic and robust framework necessary for desalination applications which yields orders of magnitude faster desalination. The electrode pairs are located so that a flow of feed water flows through or around the electrode pairs with the flow perpendicular to sequentially applied electric potentials. The system is controlled to charge the series of electrode pairs sequentially or phased. That means the charging of the second electrode pair is delayed with regard to the charging of the first electrode pair and the charging of a third electrode pair is delayed with respect to the charging of the second electrode pair.

Design and Manufacturing of Desalination System Powered by Solar Energy Using CDI Technique

NASA Astrophysics Data System (ADS)

Rostami, Mohammad Sajjad; Khashehchi, Morteza; Pipelzadeh, Ehsan

2017-11-01

Capacitive deionization (CDI) is an emerging energy efficient, low pressure and low capital intensive desalination process where ions are separated by a pure electrostatic force imposed by a small bias potential as low as 1 V That funded by an external Renewable (Solar) power supply to materials with high specific surface area. The main objective of this configuration is to separate the cation and anions on oppositely charged electrodes. One of the key parameters for commercial realization of CDI is the salt adsorption capacity of the electrodes. State-of-the-art electrode materials are based on porous activated carbon particles or carbon aerogels. Various electrode materials have been developed in the past, which have suffered from instability and lack of performance. Preliminary experimental results using carbon black, graphite powder, graphene ∖ graphite ∖ PTFE (Active ∖ Conductive ∖ binder) show that the graphene reduced via urea method is a suitable method to develop CDI electrode materials. Although some progress has been made, production of efficient and stable carbon based electrode materials for large scale desalination has not been fully realized. A new desalination technique using capacitive deionization.

Design of stand-alone brackish water desalination wind energy system for Jordan

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

Habali, S.M.; Saleh, I.A.

1994-06-01

More than 100 underground water wells drilled in Jordan are known to have brackish water with total desolved solids (TDS) over 1500 ppm but not greater than 4000 ppm. The world standard for potable water limits the TDS count to 500 ppm in addition to being free from live microorganisms or dangerous mineral and organic substances. A reverse osmosis desalination scheme powered by a stand-alone wind energy converter (WEC) is proposed to produce fresh water water from wells located in potentially high-wind sites. The purpose of this study if to present the main design parameters and economic estimates of amore » wind-assisted RO system using a diesel engine as the baseline energy source and an electric wind turbine for the wind energy source. It is found that brackish water pumping and desalinating using WECs costs 0.67 to 1.16 JD/m[sup 3] (JD = Jordanian Dinar, 1US$ = 0.68 JD), which is less than using conventional diesel engines especially in remote areas. In addition, the wind-reverse osmosis system becomes more economically feasible for higher annual production rates or in good wind regimes.« less

An Osmotic Membrane Bioreactor-Membrane Distillation System for Simultaneous Wastewater Reuse and Seawater Desalination: Performance and Implications.

PubMed

Luo, Wenhai; Phan, Hop V; Li, Guoxue; Hai, Faisal I; Price, William E; Elimelech, Menachem; Nghiem, Long D

2017-12-19

In this study, we demonstrate the potential of an osmotic membrane bioreactor (OMBR)-membrane distillation (MD) hybrid system for simultaneous wastewater reuse and seawater desalination. A stable OMBR water flux of approximately 6 L m -2 h -1 was achieved when using MD to regenerate the seawater draw solution. Water production by the MD process was higher than that from OMBR to desalinate additional seawater and thus account for draw solute loss due to the reverse salt flux. Amplicon sequencing on the Miseq Illumina platform evidenced bacterial acclimatization to salinity build-up in the bioreactor, though there was a reduction in the bacterial community diversity. In particular, 18 halophilic and halotolerant bacterial genera were identified with notable abundance in the bioreactor. Thus, the effective biological treatment was maintained during OMBR-MD operation. By coupling biological treatment and two high rejection membrane processes, the OMBR-MD hybrid system could effectively remove (>90%) all 30 trace organic contaminants of significant concern investigated here and produce high quality water. Nevertheless, further study is necessary to address MD membrane fouling due to the accumulation of organic matter, particularly protein- and humic-like substances, in seawater draw solution.

Energy extraction and water treatment in one system: The idea of using a desalination battery in a cooling tower

NASA Astrophysics Data System (ADS)

Shapira, Barak; Cohen, Izaak; Penki, Tirupathi Rao; Avraham, Eran; Aurbach, Doron

2018-02-01

The use of sodium manganese oxide as an intercalation electrode for water treatment was recently explored, and referred to as a "desalination battery" and "hybrid capacitive deionization". Here, we examine the feasibility of using such a desalination battery, comprising crystalline Na4Mn9O18 as the cathode and Ag/AgCl/Cl- electrode as the anode, to extract energy from low-grade waste heat sources. Sodium manganese oxide electrode's material was produced via a solid-state synthesis. Electrodes were produced by spray-coated onto graphite foils, and showed a temperature dependence of the electrode potential, namely, ∂ E / ∂ T , of -0.63 mV/K (whereas, the Ag/AgCl/Cl- mesh electrode showed much lower temperature dependence, < 0.1 mV/K). In order to demonstrate ion-removal capabilities together with the feasibility of thermal-energy conversion, a flow battery system was constructed. Thermally regenerative electrochemical cycles (TREC) were constructed for the flow battery cell. The thermal energy conversion, in this particular system, was shown to be feasible at relatively low C-rate (C/19) with temperatures varying between 30 °C and 70 °C.

Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

PubMed Central

Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J.; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

2016-01-01

There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes. PMID:27545955

Why do local communities support or oppose seawater desalination?

NASA Astrophysics Data System (ADS)

Mirza Ordshahi, B.; Heck, N.; Faraola, S.; Paytan, A.; Haddad, B.; Potts, D. C.

2016-12-01

Freshwater shortages have become a global problem due to increasing water consumption and environmental changes which are reducing the reliability of traditional water resources. One option to address water shortages in coastal areas is the use of seawater desalination. Desalination technology is particularly valued for the production of high quality drinking water and consistent production. However, seawater desalination is controversial due to potential environmental, economic, and societal impacts and lack of public support for this water supply method. Compared to alternative potable water production methods, such as water recycling, little is known about public attitudes towards seawater desalination and factors that shape local support or rejection. Our research addresses this gap and explores variables that influence support for proposed desalination plants in the Monterey Bay region, where multiple facilities have been proposed in recent years. Data was collected via a questionnaire-based survey among a random sample of coastal residents and marine stakeholders between June-July, 2016. Findings of the study identify the influence of socio-demographic variables, knowledge about desalination, engagement in marine activities, perception of the environmental context, and the existence of a National Marine Sanctuary on local support. Research outcome provide novel insights into public attitudes towards desalination and enhances our understanding of why communities might support or reject this water supply technology.

Purification of High Salinity Brine by Multi-Stage Ion Concentration Polarization Desalination

NASA Astrophysics Data System (ADS)

Kim, Bumjoo; Kwak, Rhokyun; Kwon, Hyukjin J.; Pham, Van Sang; Kim, Minseok; Al-Anzi, Bader; Lim, Geunbae; Han, Jongyoon

2016-08-01

There is an increasing need for the desalination of high concentration brine (>TDS 35,000 ppm) efficiently and economically, either for the treatment of produced water from shale gas/oil development, or minimizing the environmental impact of brine from existing desalination plants. Yet, reverse osmosis (RO), which is the most widely used for desalination currently, is not practical for brine desalination. This paper demonstrates technical and economic feasibility of ICP (Ion Concentration Polarization) electrical desalination for the high saline water treatment, by adopting multi-stage operation with better energy efficiency. Optimized multi-staging configurations, dependent on the brine salinity values, can be designed based on experimental and numerical analysis. Such an optimization aims at achieving not just the energy efficiency but also (membrane) area efficiency, lowering the true cost of brine treatment. ICP electrical desalination is shown here to treat brine salinity up to 100,000 ppm of Total Dissolved Solids (TDS) with flexible salt rejection rate up to 70% which is promising in a various application treating brine waste. We also demonstrate that ICP desalination has advantage of removing both salts and diverse suspended solids simultaneously, and less susceptibility to membrane fouling/scaling, which is a significant challenge in the membrane processes.

Desalination

EPA Science Inventory

To cope with the rising demand for fresh water, desalination of brackish groundwater and seawater is increasingly being viewed as a pragmatic option for augmenting fresh water supplies. The large scale deployment of desalination is likely to demonstrably increase electricity use,...

Strategies for merging microbial fuel cell technologies in water desalination processes: Start-up protocol and desalination efficiency assessment

NASA Astrophysics Data System (ADS)

Borjas, Zulema; Esteve-Núñez, Abraham; Ortiz, Juan Manuel

2017-07-01

Microbial Desalination Cells constitute an innovative technology where microbial fuel cell and electrodialysis merge in the same device for obtaining fresh water from saline water with no energy-associated cost for the user. In this work, an anodic biofilm of the electroactive bacteria Geobacter sulfurreducens was able to efficiently convert the acetate present in synthetic waste water into electric current (j = 0.32 mA cm-2) able to desalinate water. .Moreover, we implemented an efficient start-up protocol where desalination up to 90% occurred in a desalination cycle (water production:0.308 L m-2 h-1, initial salinity: 9 mS cm-1, final salinity: <1 mS cm-1) using a filter press-based MDC prototype without any energy supply (excluding peristaltic pump energy). This start-up protocol is not only optimized for time but also simplifies operational procedures making it a more feasible strategy for future scaling-up of MDCs either as a single process or as a pre-treatment method combined with other well established desalination technologies such as reverse osmosis (RO) or reverse electrodialysis.

A global flash flood forecasting system

NASA Astrophysics Data System (ADS)

Baugh, Calum; Pappenberger, Florian; Wetterhall, Fredrik; Hewson, Tim; Zsoter, Ervin

2016-04-01

The sudden and devastating nature of flash flood events means it is imperative to provide early warnings such as those derived from Numerical Weather Prediction (NWP) forecasts. Currently such systems exist on basin, national and continental scales in Europe, North America and Australia but rely on high resolution NWP forecasts or rainfall-radar nowcasting, neither of which have global coverage. To produce global flash flood forecasts this work investigates the possibility of using forecasts from a global NWP system. In particular we: (i) discuss how global NWP can be used for flash flood forecasting and discuss strengths and weaknesses; (ii) demonstrate how a robust evaluation can be performed given the rarity of the event; (iii) highlight the challenges and opportunities in communicating flash flood uncertainty to decision makers; and (iv) explore future developments which would significantly improve global flash flood forecasting. The proposed forecast system uses ensemble surface runoff forecasts from the ECMWF H-TESSEL land surface scheme. A flash flood index is generated using the ERIC (Enhanced Runoff Index based on Climatology) methodology [Raynaud et al., 2014]. This global methodology is applied to a series of flash floods across southern Europe. Results from the system are compared against warnings produced using the higher resolution COSMO-LEPS limited area model. The global system is evaluated by comparing forecasted warning locations against a flash flood database of media reports created in partnership with floodlist.com. To deal with the lack of objectivity in media reports we carefully assess the suitability of different skill scores and apply spatial uncertainty thresholds to the observations. To communicate the uncertainties of the flash flood system output we experiment with a dynamic region-growing algorithm. This automatically clusters regions of similar return period exceedence probabilities, thus presenting the at-risk areas at a spatial resolution appropriate to the NWP system. We then demonstrate how these warning areas could eventually complement existing global systems such as the Global Flood Awareness System (GloFAS), to give warnings of flash floods. This work demonstrates the possibility of creating a global flash flood forecasting system based on forecasts from existing global NWP systems. Future developments, in post-processing for example, will need to address an under-prediction bias, for extreme point rainfall, that is innate to current-generation global models.

A desalination battery.

PubMed

Pasta, Mauro; Wessells, Colin D; Cui, Yi; La Mantia, Fabio

2012-02-08

Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na(2-x)Mn(5)O(10) nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l(-1) for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (~ 0.2 Wh l(-1)), the most efficient technique presently available. © 2012 American Chemical Society

Effects of freshwater leaching on potential bioavailability of heavy metals in tidal flat soils.

PubMed

Li, Hui; Lu, Jun; Li, Qu-Sheng; He, Bao-Yan; Mei, Xiu-Qin; Yu, Dan-Ping; Xu, Zhi-Min; Guo, Shi-Hong; Chen, Hui-Jun

2016-02-01

Leaching experiments were conducted to investigate the effects of desalination levels and sediment depths on potential bioavailability of heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in tidal flat soils. The data showed that both the desalination levels (p < 0.001) and soil depths (p < 0.001) had significant effects on the concentrations of acid-volatile sulfide (AVS). AVS concentrations generally exhibited increasing trends with an increase in depth and decreasing trends with enhanced desalination levels. The desalination levels had significant (p < 0.05) effects on the concentrations of simultaneously extracted metal (SEM; Cd, Cr, Cu, Fe, Mn, Pb, and Zn). Moreover, the concentrations of SEM (Cd, Cr, Cu, Fe, Mn, Pb, and Zn) generally tended to decrease with an increase in the desalination level. The desalination treatment significantly reduced the ratios of SEM/AVS compared with control. However, the ratios of SEM/AVS increased with enhanced desalination levels in treatments. Results reveal that low desalination treatment is better for reducing toxicity to benthic organisms than high desalination treatment. Since these reclaimed tidal flats with low desalinisation are suitable for saline water aquaculture, transforming the present land use of reclaimed tidal flats from fresh water aquaculture into saline water aquaculture may reduce health risk of heavy metals remained in sediments. These results will also contribute to our understanding of the dynamic behavior of heavy metals in the reclamation of tidal flats during leaching and the role of the ratio of SEM/AVS predictions on assessing the ecological risks of reclaimed tidal flats.

Water permeability of nanoporous graphene at realistic pressures for reverse osmosis desalination

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

Cohen-Tanugi, David; Grossman, Jeffrey C.

Nanoporous graphene (NPG) shows tremendous promise as an ultra-permeable membrane for water desalination thanks to its atomic thickness and precise sieving properties. However, a significant gap exists in the literature between the ideal conditions assumed for NPG desalination and the physical environment inherent to reverse osmosis (RO) systems. In particular, the water permeability of NPG has been calculated previously based on very high pressures (1000–2000 bars). Does NPG maintain its ultrahigh water permeability under real-world RO pressures (<100 bars)? Here, we answer this question by drawing results from molecular dynamics simulations. Our results indicate that NPG maintains its ultrahigh permeabilitymore » even at low pressures, allowing a permeate water flux of 6.0 l/h-bar per pore, or equivalently 1041 ± 20 l/m{sup 2}-h-bar assuming a nanopore density of 1.7 × 10{sup 13} cm{sup −2}.« less

Design and realization of flash translation layer in tiny embedded system

NASA Astrophysics Data System (ADS)

Ren, Xiaoping; Sui, Chaoya; Luo, Zhenghua; Cao, Wenji

2018-05-01

We design a solution of tiny embedded device NAND Flash storage system on the basis of deeply studying the characteristics of widely used NAND Flash in the embedded devices in order to adapt to the development of intelligent interconnection trend and solve the storage problem of large data volume in tiny embedded system. The hierarchical structure and function purposes of the system are introduced. The design and realization of address mapping, error correction, bad block management, wear balance, garbage collection and other algorithms in flash memory transformation layer are described in details. NAND Flash drive and management are realized on STM32 micro-controller, thereby verifying design effectiveness and feasibility.

Emerging desalination technologies for water treatment: a critical review.

PubMed

Subramani, Arun; Jacangelo, Joseph G

2015-05-15

In this paper, a review of emerging desalination technologies is presented. Several technologies for desalination of municipal and industrial wastewater have been proposed and evaluated, but only certain technologies have been commercialized or are close to commercialization. This review consists of membrane-based, thermal-based and alternative technologies. Membranes based on incorporation of nanoparticles, carbon nanotubes or graphene-based ones show promise as innovative desalination technologies with superior performance in terms of water permeability and salt rejection. However, only nanocomposite membranes have been commercialized while others are still under fundamental developmental stages. Among the thermal-based technologies, membrane distillation and adsorption desalination show the most promise for enhanced performance with the availability of a waste heat source. Several alternative technologies have also been developed recently; those based on capacitive deionization have shown considerable improvements in their salt removal capacity and feed water recovery. In the same category, microbial desalination cells have been shown to desalinate high salinity water without any external energy source, but to date, scale up of the process has not been methodically evaluated. In this paper, advantages and drawbacks of each technology is discussed along with a comparison of performance, water quality and energy consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluating Non-In-Place Update Techniques for Flash-Based Transaction Processing Systems

NASA Astrophysics Data System (ADS)

Wang, Yongkun; Goda, Kazuo; Kitsuregawa, Masaru

Recently, flash memory is emerging as the storage device. With price sliding fast, the cost per capacity is approaching to that of SATA disk drives. So far flash memory has been widely deployed in consumer electronics even partly in mobile computing environments. For enterprise systems, the deployment has been studied by many researchers and developers. In terms of the access performance characteristics, flash memory is quite different from disk drives. Without the mechanical components, flash memory has very high random read performance, whereas it has a limited random write performance because of the erase-before-write design. The random write performance of flash memory is comparable with or even worse than that of disk drives. Due to such a performance asymmetry, naive deployment to enterprise systems may not exploit the potential performance of flash memory at full blast. This paper studies the effectiveness of using non-in-place-update (NIPU) techniques through the IO path of flash-based transaction processing systems. Our deliberate experiments using both open-source DBMS and commercial DBMS validated the potential benefits; x3.0 to x6.6 performance improvement was confirmed by incorporating non-in-place-update techniques into file system without any modification of applications or storage devices.

Rotating carbon nanotube membrane filter for water desalination

NASA Astrophysics Data System (ADS)

Tu, Qingsong; Yang, Qiang; Wang, Hualin; Li, Shaofan

2016-05-01

We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology.

Rotating carbon nanotube membrane filter for water desalination

PubMed Central

Tu, Qingsong; Yang, Qiang; Wang, Hualin; Li, Shaofan

2016-01-01

We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF device may significantly improve desalination efficiency by combining the centrifugal force propelled reverse osmosis process and the porous CNT-based fine scale selective separation technology. PMID:27188982

Synchronized Electronic Shutter System (SESS) for Thermal Nondestructive Evaluation

NASA Technical Reports Server (NTRS)

Zalameda, Joseph N.

2001-01-01

The purpose of this paper is to describe a new method for thermal nondestructive evaluation. This method uses a synchronized electronic shutter system (SESS) to remove the heat lamp's influence on the thermal data during and after flash heating. There are two main concerns when using flash heating. The first concern is during the flash when the photons are reflected back into the camera. This tends to saturate the detectors and potentially introduces unknown and uncorrectable errors when curve fitting the data to a model. To address this, an electronically controlled shutter was placed over the infrared camera lens. Before firing the flash lamps, the shutter is opened to acquire the necessary background data for offset calibration. During flash heating, the shutter is closed to prevent the photons from the high intensity flash from saturating the camera's detectors. The second concern is after the flash heating where the lamps radiate heat after firing. This residual cooling introduces an unwanted transient thermal response into the data. To remove this residual effect, a shutter was placed over the flash lamps to block the infrared heat radiating from the flash head after heating. This helped to remove the transient contribution of the flash. The flash lamp shutters were synchronized electronically with the camera shutter. Results are given comparing the use of the thermal inspection with and without the shutter system.

The look of into Desalination and Natural Hazard

NASA Astrophysics Data System (ADS)

Arregoitia Sarabia, C. A.

2012-04-01

Today due to climate change and population growth, cities and especially larger cities have become more water stressed. Thus the growing demand for drinkable water due to water scarcity in different World regions and its reliable supply, have persuaded humans to construct desalination plants. Today, the implementation of different large-scale desalination methods is increasing. Desalination is a separation process that consists on the removal of salts from water (seawater or brackish water) to make it suitable for other purposes. Some important environmental aspects for a desalination plant are the location of the plant, brine disposal and energy considerations. However these issues become affected when natural adversity happens. Desalination processes used are normally classified in thermal and membrane. The energy required by these processes could be of any form of heat, electrical or mechanical depending on the separation process. These types of energy derive from fossil fuels, which conditions the desalination sustainability -environmental and economical. To improve this reality, the desalination industry is making a great research effort related to novel technologies, the use of renewable energies, and brine management. Presently desalination membrane technologies are preferred over thermal ones (based on evaporation) since they allow for continuous operations close to ambient temperatures. Moreover, the offer for a wider selection of large equipment and modules is increasing. This makes it possible to design processes according to potable needs as well as ease the use of membranes and other separation technologies together. Traditionally the location of the plant is an obvious matter where selection of site should be determined by considerations of mainly energy supply available and distance in relation to feed water intake, disposal site and end-user. This means locating these plants in coastal areas or inland locations and look for a solution to then naturally dispose their brine waste. However, a desalination plant can be affected by different natural hazards depending on where they are located and therefore they should be considered when determining the optimum site for it. A natural hazard is an unexpected or uncontrollable natural event of unusual intensity that threatens people's lives or their activities. Atmospheric hazards are weather-related events, whereas geologic hazards happen on or within the Earth's surface. However, it is important to understand that the capricious force of nature can trigger catastrophes that could impact households, communities and even threaten life across the world depending on the desalination plant location. Little work has been undertaken so far to explore the impact of desalination technology when a natural event arrives. Therefore, this paper looks at the different desalination technologies and their role and impact when a natural hazard occurs because they can either be a mitigation source for water scarcity or can be turned into a greater disaster. An example is presented Keywords: desalination, water, natural hazards and megacities

Multilayer Nanoporous Graphene Membranes for Water Desalination.

PubMed

Cohen-Tanugi, David; Lin, Li-Chiang; Grossman, Jeffrey C

2016-02-10

While single-layer nanoporous graphene (NPG) has shown promise as a reverse osmosis (RO) desalination membrane, multilayer graphene membranes can be synthesized more economically than the single-layer material. In this work, we build upon the knowledge gained to date toward single-layer graphene to explore how multilayer NPG might serve as a RO membrane in water desalination using classical molecular dynamic simulations. We show that, while multilayer NPG exhibits similarly promising desalination properties to single-layer membranes, their separation performance can be designed by manipulating various configurational variables in the multilayer case. This work establishes an atomic-level understanding of the effects of additional NPG layers, layer separation, and pore alignment on desalination performance, providing useful guidelines for the design of multilayer NPG membranes.

Impact of Desalination on Physical and Mechanical Properties of Lanzhou Loess

NASA Astrophysics Data System (ADS)

Bing, Hui; Zhang, Ying; Ma, Min

2017-12-01

Soluble salt in soil has a significant influence on the physical and mechanical properties of the soil. We performed desalination experiments on Lanzhou loess, a typical sulfate saline soil, to study the effects of salt on the physical and mechanical properties of the loess and compare variations in the soil properties after desalination. The Atterberg limits of the soil increased after desalination as a result of changes in the soil particle composition and grain refinement. The shear and uniaxial compressive strength of the soil increased as a result of decreased calcitic cementation and other changes to the soil structure. Scanning electron microstructure (SEM) and mercury intrusion porosimetry (MIP) procedures revealed changes to the microstructure and pore-size distribution of the Lanzhou loess after desalination.

Flash LIDAR Systems for Planetary Exploration

NASA Astrophysics Data System (ADS)

Dissly, Richard; Weinberg, J.; Weimer, C.; Craig, R.; Earhart, P.; Miller, K.

2009-01-01

Ball Aerospace offers a mature, highly capable 3D flash-imaging LIDAR system for planetary exploration. Multi mission applications include orbital, standoff and surface terrain mapping, long distance and rapid close-in ranging, descent and surface navigation and rendezvous and docking. Our flash LIDAR is an optical, time-of-flight, topographic imaging system, leveraging innovations in focal plane arrays, readout integrated circuit real time processing, and compact and efficient pulsed laser sources. Due to its modular design, it can be easily tailored to satisfy a wide range of mission requirements. Flash LIDAR offers several distinct advantages over traditional scanning systems. The entire scene within the sensor's field of view is imaged with a single laser flash. This directly produces an image with each pixel already correlated in time, making the sensor resistant to the relative motion of a target subject. Additionally, images may be produced at rates much faster than are possible with a scanning system. And because the system captures a new complete image with each flash, optical glint and clutter are easily filtered and discarded. This allows for imaging under any lighting condition and makes the system virtually insensitive to stray light. Finally, because there are no moving parts, our flash LIDAR system is highly reliable and has a long life expectancy. As an industry leader in laser active sensor system development, Ball Aerospace has been working for more than four years to mature flash LIDAR systems for space applications, and is now under contract to provide the Vision Navigation System for NASA's Orion spacecraft. Our system uses heritage optics and electronics from our star tracker products, and space qualified lasers similar to those used in our CALIPSO LIDAR, which has been in continuous operation since 2006, providing more than 1.3 billion laser pulses to date.

An Improved B+ Tree for Flash File Systems

NASA Astrophysics Data System (ADS)

Havasi, Ferenc

Nowadays mobile devices such as mobile phones, mp3 players and PDAs are becoming evermore common. Most of them use flash chips as storage. To store data efficiently on flash, it is necessary to adapt ordinary file systems because they are designed for use on hard disks. Most of the file systems use some kind of search tree to store index information, which is very important from a performance aspect. Here we improved the B+ search tree algorithm so as to make flash devices more efficient. Our implementation of this solution saves 98%-99% of the flash operations, and is now the part of the Linux kernel.

Energy and air emission effects of water supply.

PubMed

Stokes, Jennifer R; Horvath, Arpad

2009-04-15

Life-cycle air emission effects of supplying water are explored using a hybrid life-cycle assessment For the typically sized U.S. utility analyzed, recycled water is preferable to desalination and comparable to importation. Seawater desalination has an energy and air emission footprint that is 1.5-2.4 times larger than that of imported water. However, some desalination modes fare better; brackish groundwater is 53-66% as environmentally intensive as seawater desalination. The annual water needs (326 m3) of a typical Californian that is met with imported water requires 5.8 GJ of energy and creates 360 kg of CO2 equivalent emissions. With seawater desalination, energy use would increase to 14 GJ and 800 kg of CO2 equivalent emissions. Meeting the water demand of California with desalination would consume 52% of the state's electricity. Supply options were reassessed using alternative electricity mixes, including the average mix of the United States and several renewable sources. Desalination using solar thermal energy has lower greenhouse gas emissions than that of imported and recycled water (using California's electricity mix), but using the U.S. mix increases the environmental footprint by 1.5 times. A comparison with a more energy-intensive international scenario shows that CO2 equivalent emissions for desalination in Dubai are 1.6 times larger than in California. The methods, decision support tool (WEST), and results of this study should persuade decision makers to make informed water policy choices by including energy consumption and material use effects in the decision-making process.

Synergies of solar energy use in the desalination of seawater: A case study in northern Chile

NASA Astrophysics Data System (ADS)

Servert, Jorge F.; Cerrajero, Eduardo; Fuentealba, Edward L.

2016-05-01

The mining industry is a great consumer of water for hydrometallurgical processes. Despite the efforts in minimizing the use of fresh water through reuse, recycling and process intensification, water demand for mining is expected to rise a 40% from 2013 to 2020. For seawater to be an alternative to groundwater, it must be pumped up to the mine (thousands of meters uphill) and desalinated. These processes require intensive energy and investment in desalination and piping/pumping facilities. A conventional solution for this process would be desalination by reverse osmosis at sea level, powered by electricity from the grid, and further pumping of the desalinated water uphill. This paper compares the feasibility of two solar technologies versus the "conventional" option. LCOW (Levelized Cost of Water) was used as a comparative indicator among the studied solutions, with values for a lifetime of 10, 15, 20 and 25 years, calculated using a real discount rate equal to 12%. The LCOW is lower in all cases for the RO + grid solution. The cost of desalination, ignoring the contribution of pumping, is similar for the three technologies from twenty years of operation. The use of solar energy to desalinate sea water for consumption in the mines of the Atacama region is technically feasible. However, due to the extra costs from pumping whole seawater, and not just the desalinated water, solar solutions are less competitive than the conventional process.

Planning and Design of Seawater Reverse Osmosis Desalination Plants Marine Outfalls

NASA Astrophysics Data System (ADS)

Maalouf, S.; Yeh, W. W.

2011-12-01

Increasing demands for water in urban areas and agricultural zones in arid and semi-arid regions have urged planners and regulators to look for alternative renewable water sources. Worldwide, seawater reverse osmosis (SWRO) desalination plants have become an essential supply source for the production of fresh water in such regions. Disposal of their wastes, however, has not been fully and properly addressed. This study presents a strategy for the analysis and design of optimal disposal systems of hypersaline wastes that are generated by SWRO desalination plants. The study evaluates current disposal methods and recommends ways to effectively employ multiport marine outfalls for this purpose. Such outfalls emerged as reliable means for conveying wastes from process plants, to include wastewater treatment and power plants, into the coastal waters. Their proper use, however, in conjunction with SWRO desalination plants is still in its beginning stage, and much work needs to be done to employ them effectively. Therefore, the main objective of this research is to provide design engineers with effective procedures that meet environmental permitting requirements and restrictions, while ascertaining adequate hydrodynamic performance. The study is tested by employing a simulation model and examining its reliability under many parameter perturbation scenarios. This is further extended by providing a solution to the same problem using a heuristic approach.

Ion selection of charge-modified large nanopores in a graphene sheet

NASA Astrophysics Data System (ADS)

Zhao, Shijun; Xue, Jianming; Kang, Wei

2013-09-01

Water desalination becomes an increasingly important approach for clean water supply to meet the rapidly growing demand of population boost, industrialization, and urbanization. The main challenge in current desalination technologies lies in the reduction of energy consumption and economic costs. Here, we propose to use charged nanopores drilled in a graphene sheet as ion exchange membranes to promote the efficiency and capacity of desalination systems. Using molecular dynamics simulations, we investigate the selective ion transport behavior of electric-field-driven KCl electrolyte solution through charge modified graphene nanopores. Our results reveal that the presence of negative charges at the edge of graphene nanopore can remarkably impede the passage of Cl- while enhance the transport of K+, which is an indication of ion selectivity for electrolytes. We further demonstrate that this selectivity is dependent on the pore size and total charge number assigned at the nanopore edge. By adjusting the nanopore diameter and electric charge on the graphene nanopore, a nearly complete rejection of Cl- can be realized. The electrical resistance of nanoporous graphene, which is a key parameter to evaluate the performance of ion exchange membranes, is found two orders of magnitude lower than commercially used membranes. Our results thus suggest that graphene nanopores are promising candidates to be used in electrodialysis technology for water desalinations with a high permselectivity.

DEVELOPMENT OF HIGHLY-EFFICIENT AQUAPORIN-BASED WATER TREATMENTMEMBRANES FOR DESALINATION AND CONTAMINANT REMOVAL

EPA Science Inventory

As an outcome of this project data on the applicability of protein polymer membranes for application to water desalination will be obtained. This will provide information on the stability and permeability of these membranes under simulated desalination conditions. The struct...

Improvement of water desalination technologies in reverse osmosis plants

NASA Astrophysics Data System (ADS)

Vysotskii, S. P.; Konoval'chik, M. V.; Gul'ko, S. E.

2017-07-01

The strengthening of requirements for the protection of surface-water sources and increases in the cost of reagents lead to the necessity of using membrane (especially, reverse osmosis) technologies of water desalination as an alternative to ion-exchange technologies. The peculiarities of using reverse osmosis technologies in the desalination of waters with an increased salinity have been discussed. An analogy has been made between the dependence of the adsorptive capacity of ion-exchange resins on the reagent consumption during ion exchange and the dependence of the specific ion flux on the voltage in the electrodialysis and productivity of membrane elements on the excess of the pressure of source water over the osmotic pressure in reverse osmosis. It has been proposed to regulate the number of water desalination steps in reverse osmosis plants, which makes it possible to flexibly change the productivity of equipment and the level of desalinization, depending on the requirements for the technological process. It is shown that the selectivity of reverse osmotic membranes with respect to bivalent ions (calcium, magnesium, and sulfates) is approximately four times higher than the selectivity with respect to monovalent ions (sodium and chlorine). The process of desalination in reverse osmosis plants depends on operation factors, such as the salt content and ion composition of source water, the salt content of the concentrate, and the temperatures of solution and operating pressure, and the design features of devices, such as the length of the motion of the desalination water flux, the distance between membranes, and types of membranes and turbulators (spacers). To assess the influence of separate parameters on the process of reverse osmosis desalination of water solutions, we derived criteria equations by compiling problem solution matrices on the basis of the dimensional method, taking into account the Huntley complement. The operation of membrane elements was analyzed and the dependence of the output of desalinated water (permeate) through the membranes on the pressure of influent water for desalination and the dependence of the permeate output on the water viscosity and the dependence of the specific permeate output on the velocity and length of the motion of the desalination water flux were built. The values of the optimum pressure of source influent water for desalination in a reverse osmosis device were found. Provided the current prices for membrane elements (800 to 1200 USD) and cost of electricity (0.06-0.1 USD), the optimum pressure is 1.0 to 1.4 MPa.

Optimization study of small-scale solar membrane distillation desalination systems (s-SMDDS).

PubMed

Chang, Hsuan; Chang, Cheng-Liang; Hung, Chen-Yu; Cheng, Tung-Wen; Ho, Chii-Dong

2014-11-24

Membrane distillation (MD), which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS) is a potential technology for resolving energy and water resource problems. Small-scale SMDDS (s-SMDDS) is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo-steady-state approach for equipment sizing and dynamic optimization using overall system mathematical models. Two s-SMDDS employing an air gap membrane distillation module with membrane areas of 11.5 m(2) and 23 m(2) are analyzed. The lowest water production costs are $5.92/m(3) and $5.16/m(3) for water production rates of 500 kg/day and 1000 kg/day, respectively. For these two optimal cases, the performance ratios are 0.85 and 0.91; the recovery ratios are 4.07% and 4.57%. The effect of membrane characteristics on the production cost is investigated. For the commercial membrane employed in this study, the increase of the membrane mass transfer coefficient up to two times is beneficial for cost reduction.

Optimization Study of Small-Scale Solar Membrane Distillation Desalination Systems (s-SMDDS)

PubMed Central

Chang, Hsuan; Chang, Cheng-Liang; Hung, Chen-Yu; Cheng, Tung-Wen; Ho, Chii-Dong

2014-01-01

Membrane distillation (MD), which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS) is a potential technology for resolving energy and water resource problems. Small-scale SMDDS (s-SMDDS) is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo-steady-state approach for equipment sizing and dynamic optimization using overall system mathematical models. Two s-SMDDS employing an air gap membrane distillation module with membrane areas of 11.5 m2 and 23 m2 are analyzed. The lowest water production costs are $5.92/m3 and $5.16/m3 for water production rates of 500 kg/day and 1000 kg/day, respectively. For these two optimal cases, the performance ratios are 0.85 and 0.91; the recovery ratios are 4.07% and 4.57%. The effect of membrane characteristics on the production cost is investigated. For the commercial membrane employed in this study, the increase of the membrane mass transfer coefficient up to two times is beneficial for cost reduction. PMID:25421065

CCD high-speed videography system with new concepts and techniques

NASA Astrophysics Data System (ADS)

Zheng, Zengrong; Zhao, Wenyi; Wu, Zhiqiang

1997-05-01

A novel CCD high speed videography system with brand-new concepts and techniques is developed by Zhejiang University recently. The system can send a series of short flash pulses to the moving object. All of the parameters, such as flash numbers, flash durations, flash intervals, flash intensities and flash colors, can be controlled according to needs by the computer. A series of moving object images frozen by flash pulses, carried information of moving object, are recorded by a CCD video camera, and result images are sent to a computer to be frozen, recognized and processed with special hardware and software. Obtained parameters can be displayed, output as remote controlling signals or written into CD. The highest videography frequency is 30,000 images per second. The shortest image freezing time is several microseconds. The system has been applied to wide fields of energy, chemistry, medicine, biological engineering, aero- dynamics, explosion, multi-phase flow, mechanics, vibration, athletic training, weapon development and national defense engineering. It can also be used in production streamline to carry out the online, real-time monitoring and controlling.

Solar-hydrogen energy system for Pakistan

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

Lutfi, N.

1990-01-01

A solar-hydrogen energy system has been proposed for Pakistan as the best replacement for the present fossil fuel based energy system. It has been suggested to produce hydrogen via photovoltaic-electrolysis, utilizing the available non-agricultural sunny terrain in Baluchistan region. There will be a desalination plant for sea water desalination. The area under the photovoltaic panels with the availability of water would provide suitable environment for growing some cash crops. This would change the cast useless desert land into green productive farms. In order to show the quantitative benefits of the proposed system, future trends of important energy and economical parametersmore » have been studied with and without hydrogen introduction. The following parameters have been included: population, energy demand (fossil + hydrogen), energy production (fossil + hydrogen), gross national product, fossil energy imports, world energy prices, air pollution, quality of life, environmental savings due to hydrogen introduction, savings due to the higher utilization efficiency of hydrogen, by-product credit, agricultural income, income from hydrogen sale, photovoltaic cell area, total land area, water desalination plant capacity, capital investment, operating and maintenance cost, and total income from the system. The results indicate that adopting the solar-hydrogen energy system would eliminate the import dependency of fossil fuels, increase gross product per capita, reduce pollution, improve quality of life and establish a permanent and clean energy system. The total annual expenditure on the proposed system is less than the total income from the proposed system. The availability of water, the cash crop production, electricity and hydrogen would result in rapid development of Baluchistan, the largest province of Pakistan.« less

Nonlinear dynamic model of a gear-rotor-bearing system considering the flash temperature

NASA Astrophysics Data System (ADS)

Gou, Xiangfeng; Zhu, Lingyun; Qi, Changjun

2017-12-01

The instantaneous flash temperature is an important factor for gears in service. To investigate the effect of the flash temperature of a tooth surface on the dynamics of the spur gear system, a modified nonlinear dynamic model of a gear-rotor-bearing system is established. The factors such as the contact temperature of the tooth surface, time-varying stiffness, tooth surface friction, backlash, the comprehensive transmission error and so on are considered. The flash temperature of a tooth surface of pinion and gear is formulated according to Blok's flash temperature theory. The mathematical expression of the contact temperature of the tooth surface varied with time is derived and the tooth profile deformation caused by the change of the flash temperature of the tooth surface is calculated. The expression of the mesh stiffness varied with the flash temperature of the tooth surface is derived based on Hertz contact theory. The temperature stiffness is proposed and added to the nonlinear dynamic model of the system. The influence of load on the flash temperature of the tooth surface is analyzed in the parameters plane. The variation of the flash temperature of the tooth surface is studied. The numerical results indicate that the calculated method of the flash temperature of the gear tooth surface is effective and it can reflect the rules for the change of gear meshing temperature and sliding of the gear tooth surface. The effects of frequency, backlash, bearing clearance, comprehensive transmission error and time-varying stiffness on the nonlinear dynamics of the system are analyzed according to the bifurcation diagrams, Top Lyapunov Exponent (TLE) spectrums, phase portraits and Poincaré maps. Some nonlinear phenomena such as periodic bifurcation, grazing bifurcation, quasi-periodic bifurcation, chaos and its routes to chaos are investigated and the critical parameters are identified. The results provide an understanding of the system and serve as a useful reference in designing such systems.

Science Communication and Desalination Research: Water Experts' Views

ERIC Educational Resources Information Center

Schibeci, R. A.; Williams, A. J.

2014-01-01

Access to clean drinking water is a major problem for many people across the world. Desalination is being increasingly used in many countries to provide this important resource. Desalination technology has received varying degrees of support in the communities in which this technology has been adopted. Productive communication suggests we…

Forward-Osmosis Desalination with Poly(Ionic Liquid) Hydrogels as Smart Draw Agents.

PubMed

Fan, Xuelin; Liu, Huili; Gao, Yating; Zou, Zhu; Craig, Vincent S J; Zhang, Guangzhao; Liu, Guangming

2016-06-01

The combination of high desalination efficiency, negligible draw-solute leakage, nontoxicity, ease of regeneration, and effective separation to produce liquid water makes the smart draw agents developed here highly suited for forward-osmosis desalination. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Review of Knowledge on the Occurrence, Chemical Composition, and Potential Use for Desalination of Saline Ground Water in Arizona, New Mexico, and Texas with a Discussion of Potential Future Study Needs

DTIC Science & Technology

2004-01-01

Parsons Company and Texas Water Development Board, 1967; Schultz and others, 1967; Morris and Prehn , 1971; and Stucky and Arnwine, 1971). Desalination is...Inland desalination operations commonly dispose of concentrate using evaporation ponds (Morris and Prehn , 1971; Stucky and Arnwine, 1971) or deep-well...New Mexico, 1976). The potential contribution of desalination to water supply in New Mexico has been discussed by Morris and Prehn (1971) and Stucky

An exergy approach to efficiency evaluation of desalination

NASA Astrophysics Data System (ADS)

Ng, Kim Choon; Shahzad, Muhammad Wakil; Son, Hyuk Soo; Hamed, Osman A.

2017-05-01

This paper presents an evaluation process efficiency based on the consumption of primary energy for all types of practical desalination methods available hitherto. The conventional performance ratio has, thus far, been defined with respect to the consumption of derived energy, such as the electricity or steam, which are susceptible to the conversion losses of power plants and boilers that burned the input primary fuels. As derived energies are usually expressed by the units, either kWh or Joules, these units cannot differentiate the grade of energy supplied to the processes accurately. In this paper, the specific energy consumption is revisited for the efficacy of all large-scale desalination plants. In today's combined production of electricity and desalinated water, accomplished with advanced cogeneration concept, the input exergy of fuels is utilized optimally and efficiently in a temperature cascaded manner. By discerning the exergy destruction successively in the turbines and desalination processes, the relative contribution of primary energy to the processes can be accurately apportioned to the input primary energy. Although efficiency is not a law of thermodynamics, however, a common platform for expressing the figures of merit explicit to the efficacy of desalination processes can be developed meaningfully that has the thermodynamic rigor up to the ideal or thermodynamic limit of seawater desalination for all scientists and engineers to aspire to.

Evaluating options for balancing the water-electricity nexus in California: part 1--securing water availability.

PubMed

Tarroja, Brian; AghaKouchak, Amir; Sobhani, Reza; Feldman, David; Jiang, Sunny; Samuelsen, Scott

2014-11-01

The technical potential and effectiveness of different water supply options for securing water availability in a large-scale, interconnected water supply system under historical and climate-change augmented inflow and demand conditions were compared. Part 1 of the study focused on determining the scale of the options required to secure water availability and compared the effectiveness of different options. A spatially and temporally resolved model of California's major surface reservoirs was developed, and its sensitivity to urban water conservation, desalination, and water reuse was examined. Potential capacities of the different options were determined. Under historical (baseline) hydrology conditions, many individual options were found to be capable of securing water availability alone. Under climate change augment conditions, a portfolio approach was necessary. The water savings from many individual options other than desalination were insufficient in the latter, however, relying on seawater desalination alone requires extreme capacity installations which have energy, brine disposal, management, and cost implications. The importance of identifying and utilizing points of leverage in the system for choosing where to deploy different options is also demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

A framework for investigating the interactions between climate, dust, solar power generation and water desalination processes in Desert Climate

NASA Astrophysics Data System (ADS)

Siam, M. S.; Alqatari, S.; Ibrahim, H. D.; AlAloula, R. A.; Alrished, M.; AlSaati, A.; Eltahir, E. A. B.

2016-12-01

Increasing water demand in Saudi Arabia due to rapid population growth has forced the rapid expansion of seawater desalination plants in order to meet both current and future freshwater needs. Saudi Arabia has a huge potential for solar energy, hence, solar-powered desalination plants provide an opportunity to sustainably address the freshwater demand in the kingdom without relying on fossil fuels energy. However, the desert climate of Saudi Arabia and limited access to the open ocean imposes several challenges to the expansion and sustainability of solar-powered desalination plants. For example, the frequent and intense dust storms that occur in the region can degrade solar panels and significantly reduce their efficiency. Moreover, the high salinity Arabian Gulf is both the source of feedwater and sink of hypersaline discharge (brine) for many plants in the east of the Kingdom, and the brine may alter the salinity, temperature and movement of the water thereby reducing the quality of the feedwater to the desalination plants. Here, we propose a framework to investigate the different interactions between climate, dust, solar power generation and seawater desalination in order to identify optimal parameters such as locations of solar panels and seawater intake for sustainable implementation of solar-powered desalination plants. This framework integrates several numerical models including regional climate, hydrodynamics, Photovoltaics (PV) and Photovoltaic-Reverse Osmosis (PV-RO) models that are used to investigate these interactions for a solar-powered desalination plant at AlKhafji on the Northeastern coast of Saudi Arabia.

Efficiently Combining Water Reuse and Desalination through Forward Osmosis-Reverse Osmosis (FO-RO) Hybrids: A Critical Review.

PubMed

Blandin, Gaetan; Verliefde, Arne R D; Comas, Joaquim; Rodriguez-Roda, Ignasi; Le-Clech, Pierre

2016-07-01

Forward osmosis (FO) is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO) hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application) and water management challenges (proximity of wastewater and desalination plants), FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO) demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs) in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling.

Efficiently Combining Water Reuse and Desalination through Forward Osmosis—Reverse Osmosis (FO-RO) Hybrids: A Critical Review

PubMed Central

Blandin, Gaetan; Verliefde, Arne R.D.; Comas, Joaquim; Rodriguez-Roda, Ignasi; Le-Clech, Pierre

2016-01-01

Forward osmosis (FO) is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO) hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application) and water management challenges (proximity of wastewater and desalination plants), FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO) demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs) in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling. PMID:27376337

Bioelectrochemical desalination and electricity generation in microbial desalination cell with dewatered sludge as fuel.

PubMed

Meng, Fanyu; Jiang, Junqiu; Zhao, Qingliang; Wang, Kun; Zhang, Guodong; Fan, Qingxin; Wei, Liangliang; Ding, Jing; Zheng, Zhen

2014-04-01

Microbial desalination cells (MDCs) with common liquid anodic substrate exhibit a slow startup and destructive pH drop, and abiotic cathodes have high cost and low sustainability. A biocathode MDC with dewatered sludge as fuel was developed for synergistic desalination, electricity generation and sludge stabilization. Experimental results indicated that the startup period was reduced to 3d, anodic pH was maintained between 6.6 and 7.6, and high stability was shown under long-term operation (300d). When initial NaCl concentrations were 5 and 10g/L, the desalinization rates during stable operation were 46.37±1.14% and 40.74±0.89%, respectively. The maximum power output of 3.178W/m(3) with open circuit voltage (OCV) of 1.118V was produced on 130d. After 300d, 25.71±0.15% of organic matter was removed. These results demonstrated that dewatered sludge was an appropriate anodic substrate to enhance MDC stability for desalination and electricity generation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Coastal Residents Ocean Literacy about Seawater Desalination and its Impacts on Marine Ecosystems in the Monterey Bay

NASA Astrophysics Data System (ADS)

Faraola, S.; Heck, N.; Mirza Ordshahi, B.; Paytan, A.; Petersen, K. L.; Haddad, B.; Potts, D. C.

2016-12-01

The current lack of available freshwater in California has brought about the consideration of utilizing seawater desalination to provide a consistent drinking water source for local residents of coastal areas. Public literacy about this technology and its impacts on the ocean is vital to making informed policy decisions about marine resources and ecosystems, which may empower local communities to become more involved stewards of the ocean. Our study evaluates public literacy about seawater desalination and its impacts on the ocean. Data was collected using a questionnaire-based survey from a randomly selected sample of residents and marine stakeholders in coastal communities around Monterey Bay. The study explored (1) self-assessed and accurate knowledge about marine impacts from seawater desalination and (2) what shapes public literacy concerning pertinent ocean issues in communities near a National Marine Sanctuary. Our findings show to what extent the public is prepared to engage in meaningful discussions about marine issues and seawater desalination and if an understanding of the ocean shapes perceptions on saltwater desalination.

Integrating Desalination and Energy Storage using a Saltwater-based Hybrid Sodium-ion Supercapacitor.

PubMed

Guo, Zhaowei; Ma, Yuanyuan; Dong, Xiaoli; Hou, Mengyan; Wang, Yonggang; Xia, Yongyao

2018-06-11

Ever-increasing freshwater scarcity and energy crisis problems require efficient seawater desalination and energy storage technologies; however, each target is generally considered separately. Herein, a hybrid sodium-ion supercapacitor, involving a carbon-coated nano-NaTi 2 (PO 4 ) 3 -based battery anode and an activated-carbon-based capacitive cathode, is developed to combine desalination and energy storage in one device. On charge, the supercapacitor removes salt in a flowing saltwater electrolyte through Cl - electrochemical adsorption at the cathode and Na + intercalation at the anode. Discharge delivers useful electric energy and regenerates the electrodes. This supercapacitor can be used not only for energy storage with promising electrochemical performance (i.e., high power, high efficiency, and long cycle life), but also as a desalination device with desalination capacity of 146.8 mg g -1 , much higher than most reported capacitive and battery desalination devices. Finally, we demonstrate renewables to usable electric energy and desalted water through combining commercial photovoltaics and this hybrid supercapacitor. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The end of scarcity? Water desalination as the new cornucopia for Mediterranean Spain

NASA Astrophysics Data System (ADS)

March, Hug; Saurí, David; Rico-Amorós, Antonio M.

2014-11-01

In this paper we explore the new orientation taken by Spanish water policy since the beginning of the 21st century and very specifically the shift towards desalination as an alternative to other water supply options such as river regulation or inter-basin water transfers. Desalination has been seen as the cure for everything that dams and inter-basin water transfers were unable to solve, including droughts, scarcities, social conflicts, environmental impacts, and political rivalries among the different Spanish regions. Desalination also means a new and powerful element in water planning and management that could provide water for the continuous expansion of the urban and tourist growth machine in Mediterranean Spain and thus relax possible water constraints on this growth. However, by 2012 most new desalination plants along the Mediterranean coast remained almost idle. Focusing on the case of the Mancomunidad de los Canales del Taibillla in South-eastern Spain, our aim is to develop a critical, integrated and reflexive perspective on the use of desalination as a source of water for urban and regional growth.

Solar-Cooled Hotel in the Virgin Islands

NASA Technical Reports Server (NTRS)

Harber, H.

1982-01-01

Performance of solar cooling system is described in 21-page report. System provides cooling for public areas including ball rooms, restaurant, lounge, lobby and shops. Chilled water from solar-cooling system is also used to cool hot water from hotel's desalinization plant.

An investigation of desalination by nanofiltration, reverse osmosis and integrated (hybrid NF/RO) membranes employed in brackish water treatment.

PubMed

Talaeipour, M; Nouri, J; Hassani, A H; Mahvi, A H

2017-01-01

As an appropriate tool, membrane process is used for desalination of brackish water, in the production of drinking water. The present study aims to investigate desalination processes of brackish water of Qom Province in Iran. This study was carried out at the central laboratory of Water and Wastewater Company of the studied area. To this aim, membrane processes, including nanofiltration (NF) and reverse osmosis (RO), separately and also their hybrid process were applied. Moreover, water physical and chemical parameters, including salinity, total dissolved solids (TDS), electric conductivity (EC), Na +1 and Cl -1 were also measured. Afterward, the rejection percent of each parameter was investigated and compared using nanofiltration and reverse osmosis separately and also by their hybrid process. The treatment process was performed by Luna domestic desalination device, which its membrane was replaced by two NF90 and TW30 membranes for nanofiltration and reverse osmosis processes, respectively. All collected brackish water samples were fed through membranes NF90-2540, TW30-1821-100(RO) and Hybrid (NF/RO) which were installed on desalination household scale pilot (Luna water 100GPD). Then, to study the effects of pressure on permeable quality of membranes, the simulation software model ROSA was applied. Results showed that percent of the salinity rejection was recorded as 50.21%; 72.82 and 78.56% in NF, RO and hybrid processes, respectively. During the study, in order to simulate the performance of nanofiltartion, reverse osmosis and hybrid by pressure drive, reverse osmosis system analysis (ROSA) model was applied. The experiments were conducted at performance three methods of desalination to remove physic-chemical parameters as percentage of rejections in the pilot plant are: in the NF system the salinity 50.21, TDS 43.41, EC 43.62, Cl 21.1, Na 36.15, and in the RO membrane the salinity 72.02, TDS 60.26, EC 60.33, Cl 43.08, Na 54.41. Also in case of the rejection in hybrid system of those parameters and ions included salinity 78.65, TDS 76.52, EC 76.42, Cl 63.95, and Na 70.91. Comparing rejection percent in three above-mentioned methods, it could be concluded that, in reverse osmosis process, ions and non-ion parameters rejection ability were rather better than nanofiltration process, and also better in hybrid compared to reverse osmosis process. The results reported in this paper indicate that the integration of membrane nanofiltration with reverse osmosis (hybrid NF/RO) can be completed by each other probably to remove salinity, TDS, EC, Cl, and Na.

Motorist actions at a crosswalk with an in-pavement flashing light system.

PubMed

Karkee, Ganesh J; Nambisan, Shashi S; Pulugurtha, Srinivas S

2010-12-01

An in-pavement flashing light system is used at crosswalks to alert motorists and pedestrians of possible conflicts and to influence their behavior to enhance safety. The relative behaviors of the drivers and the pedestrians affect safety. An evaluation of motorist behavior at a pedestrian crosswalk with an in-pavement flashing light system is presented in this manuscript. Field observations provide the basis to evaluate motorist behavior at a crosswalk with an in-pavement flashing light system. Outcomes of pedestrian and motorists actions were observed to quantify measures of effectiveness (MOEs) such as yielding behavior of motorists, vehicle speeds, and yielding distance from the crosswalk. A before-and-after study design was used. The before condition was prior to the activation of the in-pavement flashing light system and the after condition was after the activation of the in-pavement flashing light system. The study was conducted on a relatively low-volume roadway located in the Henderson, Nevada. The significance of the differences in the MOEs between the 2 study periods was evaluated using statistical analysis tools such as a one-tailed test for proportions and the Welch-Satterthwaite t-test. The results show that the installation of the in-pavement flashing light system increased the yielding behavior of motorists significantly (P < 0.001). The vehicular speeds decreased when pedestrians were waiting at the curb to cross and when they were crossing (P < 0.001). Motorists yielded to pedestrians on an average about 3 m (∼10 feet) upstream from the yield markings and the yielding distances were consistent in both directions. The in-pavement flashing light system is seen to be effective to improve motorists' yielding behavior and the speeds of vehicles were also observed to decrease in the presence of pedestrians.

Desalinated drinking water in the GCC countries - The need to address consumer perceptions.

PubMed

Shomar, Basem; Hawari, Jalal

2017-10-01

The Gulf Cooperation Council (GCC) countries consist of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates. These countries depend mainly on seawater desalination to meet their water needs. Although great emphasis is given to characterize desalinated water for its physicochemical and microbial properties, e.g. presence of metals, other organic contaminants and for bacteria, sensorial characteristics including smell, taste and color have not received the same attention. This is possibly attributed to the fact that inhabitants of GCC States do not use desalinated tap water for drinking consumption, rather they depend on locally produced or imported bottled water where color, taste and odor are not problematic. To address the consumer needs and perceptions of drinking desalinated water in GCC countries, water quality standards and guidelines, should respond to the public concern about other sensorial characteristics (organoleptic properties) including taste, odor, and trigeminal sensations. Often the root causes of color and smell in water are attributed to the presence of organic and inorganic contaminants and to bacterial growth which is frequently accompanied by the production of metabolites and byproducts that are obnoxious. The unpleasant sensorial problems associated with desalinated drinking tap water may constitute the driving force for most people in GCC countries to depend on bottled water. To encourage people in the GCC countries to consume desalinated tap water, it is essential that water testing include measurements of physicochemical properties, biofilm presence and organoleptic parameters to improve overall water quality. This review highlights the contribution of organoleptics for consumers of desalinated tap water. It extends water quality research to be addressed by standards for organoleptic parameters in desalinated drinking water. Accordingly, consumer awareness and outreach campaigns should be implemented to encourage people to drink tap water in the GCC countries. Copyright © 2017 Elsevier Inc. All rights reserved.

Desalination of brick masonry and stone carvings in Capitullum hall of Riga Dome Cathedral

NASA Astrophysics Data System (ADS)

Grave, J.; Krage, L.; Lusis, R.; Vitina, I.

2011-12-01

The construction of Riga Dome Cathedral and its Capithullum hall were initiated in 1211. Through centuries they were damaged a lot due to migration of soluble salts and moisture. During the last restoration (1888-1891) a lot of mistakes were conceded and subsequently some of probable solutions for restoration were unsuccessful. In 2009 the new restoration stage in Capithullum hall was started. Two types of desalination methods were used in hall - desalination with lime-sand plaster and poultice of lignin. Both quantitative and semiquantitative chemical analyses were performed in order to appreciate the desalination process.

Compact and reliable triggering method for near muzzle flash radiography

NASA Astrophysics Data System (ADS)

Lee, Eun S.; Hwang, Eul H.; Yim, Dong W.; Song, So Y.

1993-01-01

Precise timing for x-ray bursts is crucial in acquiring useful information from flash radiographic experiments. Triggering the flash x-ray system near the muzzle is a difficult task because of the intrinsic nature of the muzzle blast. In this work a compact and reliable triggering method for near muzzle flash radiography is introduced; a piezoelectric pin probe attached at the end of the barrel. These types of probes have not been activated by the precursor shock wave, but they have been activated by the main blast wave only. Reliability in triggering the flash x-ray system has been confirmed throughout a series of flash radiographic experiments near the muzzle for gun barrels with calibers up to 105 mm.

Cloud-to-ground lightning activity in Colombia: A 14-year study using lightning location system data

NASA Astrophysics Data System (ADS)

Herrera, J.; Younes, C.; Porras, L.

2018-05-01

This paper presents the analysis of 14 years of cloud-to-ground lightning activity observation in Colombia using lightning location systems (LLS) data. The first Colombian LLS operated from 1997 to 2001. After a few years, this system was upgraded and a new LLS has been operating since 2007. Data obtained from these two systems was analyzed in order to obtain lightning parameters used in designing lightning protection systems. The flash detection efficiency was estimated using average peak current maps and some theoretical results previously published. Lightning flash multiplicity was evaluated using a stroke grouping algorithm resulting in average values of about 1.0 and 1.6 for positive and negative flashes respectively and for both LLS. The time variation of this parameter changes slightly for the years considered in this study. The first stroke peak current for negative and positive flashes shows median values close to 29 kA and 17 kA respectively for both networks showing a great dependence on the flash detection efficiency. The average percentage of negative and positive flashes shows a 74.04% and 25.95% of occurrence respectively. The daily variation shows a peak between 23 and 02 h. The monthly variation of this parameter exhibits a bimodal behavior typical of the regions located near The Equator. The lightning flash density was obtained dividing the study area in 3 × 3 km cells and resulting in maximum average values of 25 and 35 flashes km- 2 year- 1 for each network respectively. A comparison of these results with global lightning activity hotspots was performed showing good correlation. Besides, the lightning flash density variation with altitude shows an inverse relation between these two variables.

Low-Energy Water Recovery from Subsurface Brines

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

Choi, Young Chul; Kim, Gyu Dong; Hendren, Zachary

A novel non-aqueous phase solvent (NAS) desalination process was proposed and developed in this research project. The NAS desalination process uses less energy than thermal processes, doesn’t require any additional chemicals for precipitation, and can be utilized to treat high TDS brine. In this project, our experimental work determined that water solubility changes and selective absorption are the key characteristics of NAS technology for successful desalination. Three NAS desalination mechanisms were investigated: (1) CO2 switchable, (2) high-temp absorption to low-temp desorption (thermally switchable), and (3) low-temp absorption to high-temp desorption (thermally switchable). Among these mechanisms, thermally switchable (low-temp absorption tomore » high-temp desorption) showed the highest water recovery and relatively high salt rejection. A test procedure for semi-continuous, bench scale NAS desalination process was also developed and used to assess performance under a range of conditions.« less

Decision support system for road closures in flash flood emergencies.

DOT National Transportation Integrated Search

2013-06-01

Among all the natural hazards, flash flood ranks as the No. 1 weather-related killer in U.S. More : than half of the deaths in flash flood are due to drowning victims in a traffic environment. So road : closure is critical to save lives from flash fl...

Reverse osmosis desalination of chitosan cross-linked graphene oxide/titania hybrid lamellar membranes.

PubMed

Deng, Hui; Sun, Penzhan; Zhang, Yingjiu; Zhu, Hongwei

2016-07-08

With excellent mass transport properties, graphene oxide (GO)-based lamellar membranes are believed to have great potential in water desalination. In order to quantify whether GO-based membranes are indeed suitable for reverse osmosis (RO) desalination, three sub-micrometer thick GO-based lamellar membranes: GO-only, reduced GO (RGO)/titania (TO) nanosheets and RGO/TO/chitosan (CTS) are prepared, and their RO desalination performances are evaluated in a home-made RO test apparatus. The photoreduction of GO by TO improves the salt rejection, which increases slowly with the membrane thickness. The RGO/TO/CTS hybrid membranes exhibit higher rejection rates of only about 30% (greater than threefold improvement compared with a GO-only membrane) which is still inferior compared to other commercial RO membranes. The low rejection rates mainly arise from the pressure-induced weakening of the ion-GO interlayer interactions. Despite the advantages of simple, low-cost preparation, high permeability and selectivity of GO-based lamellar membranes, as the current desalination performances are not high enough to afford practical application, there still remains a great challenge to realize high performance separation membranes for water desalination applications.

Enhancing biodegradation and energy generation via roughened surface graphite electrode in microbial desalination cell.

PubMed

Ebrahimi, Atieh; Yousefi Kebria, Daryoush; Najafpour Darzi, Ghasem

2017-09-01

The microbial desalination cell (MDC) is known as a newly developed technology for water and wastewater treatment. In this study, desalination rate, organic matter removal and energy production in the reactors with and without desalination function were compared. Herein, a new design of plain graphite called roughened surface graphite (RSG) was used as the anode electrode in both microbial fuel cell (MFC) and MDC reactors for the first time. Among the three type of anode electrodes investigated in this study, RSG electrode produced the highest power density and salt removal rate of 10.81 W/m 3 and 77.6%, respectively. Such a power density was 2.33 times higher than the MFC reactor due to the junction potential effect. In addition, adding the desalination function to the MFC reactor enhanced columbic efficiency from 21.8 to 31.4%. These results provided a proof-of-concept that the use of MDC instead of MFC would improve wastewater treatment efficiency and power generation, with an added benefit of water desalination. Furthermore, RSG can successfully be employed in an MDC or MFC, enhancing the bio-electricity generation and salt removal.

Acupuncture as treatment of hot flashes and the possible role of calcitonin gene-related Peptide.

PubMed

Spetz Holm, Anna-Clara E; Frisk, Jessica; Hammar, Mats L

2012-01-01

The mechanisms behind hot flashes in menopausal women are not fully understood. The flashes in women are probably preceded by and actually initiated by a sudden downward shift in the set point for the core body temperature in the thermoregulatory center that is affected by sex steroids, β-endorphins, and other central neurotransmitters. Treatments that influence these factors may be expected to reduce hot flashes. Since therapy with sex steroids for hot flashes has appeared to cause a number of side effects and risks and women with hot flashes and breast cancer as well as men with prostate cancer and hot flashes are prevented from sex steroid therapy there is a great need for alternative therapies. Acupuncture affecting the opioid system has been suggested as an alternative treatment option for hot flashes in menopausal women and castrated men. The heat loss during hot flashes may be mediated by the potent vasodilator and sweat gland activator calcitonin gene-related peptide (CGRP) the concentration of which increases in plasma during flashes in menopausal women and, according to one study, in castrated men with flushes. There is also evidence for connections between the opioid system and the release of CGRP. In this paper we discuss acupuncture as a treatment alternative for hot flashes and the role of CGRP in this context.

DESALINATION AND WATER TREATMENT RESEARCH AT SANDIA NATIONAL LABORATORIES.

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

Rigali, Mark J.; Miller, James E.; Altman, Susan J.

Water is the backbone of our economy - safe and adequate supplies of water are vital for agriculture, industry, recreation, and human consumption. While our supply of water today is largely safe and adequate, we as a nation face increasing water supply challenges in the form of extended droughts, demand growth due to population increase, more stringent health-based regulation, and competing demands from a variety of users. To meet these challenges in the coming decades, water treatment technologies, including desalination, will contribute substantially to ensuring a safe, sustainable, affordable, and adequate water supply for the United States. This overview documentsmore » Sandia National Laboratories' (SNL, or Sandia) Water Treatment Program which focused on the development and demonstration of advanced water purification technologies as part of the larger Sandia Water Initiative. Projects under the Water Treatment Program include: (1) the development of desalination research roadmaps (2) our efforts to accelerate the commercialization of new desalination and water treatment technologies (known as the 'Jump-Start Program),' (3) long range (high risk, early stage) desalination research (known as the 'Long Range Research Program'), (4) treatment research projects under the Joint Water Reuse & Desalination Task Force, (5) the Arsenic Water Technology Partnership Program, (6) water treatment projects funded under the New Mexico Small Business Administration, (7) water treatment projects for the National Energy Technology Laboratory (NETL) and the National Renewable Energy Laboratory (NREL), (8) Sandia- developed contaminant-selective treatment technologies, and finally (9) current Laboratory Directed Research and Development (LDRD) funded desalination projects.« less

Development Of A Flash X-Ray Scanner For Stereoradiography And CT

NASA Astrophysics Data System (ADS)

Endorf, Robert J.; DiBianca, Frank A.; Fritsch, Daniel S.; Liu, Wen-Ching; Burns, Charles B.

1989-05-01

We are developing a flash x-ray scanner for stereoradiography and CT which will be able to produce a stereoradiograph in 30 to 70 ns and a complete CT scan in one microsecond. This type of imaging device will be valuable in studying high speed processes, high acceleration, and traumatic events. We have built a two channel flash x-ray system capable of producing stereo radiographs with stereo angles of from 15 to 165 degrees. The dynamic and static Miff 's for the flash x-ray system were measured and compared with similar MIT's measured for a conventional medical x-ray system. We have written and tested a stereo reconstruction algorithm to determine three dimensional space points from corresponding points in the two stereo images. To demonstrate the ability of the system to image traumatic events, a radiograph was obtained of a bone undergoing a fracture. The effects of accelerations of up to 600 g were examined on radiographs taken of human kidney tissue samples in a rapidly rotating centrifuge. Feasibility studies of CT reconstruction have been performed by making simulated Cr images of various phantoms for larger flash x-ray systems of from 8 to 29 flash x-ray tubes.

Co-design of application software and NAND flash memory in solid-state drive for relational database storage system

NASA Astrophysics Data System (ADS)

Miyaji, Kousuke; Sun, Chao; Soga, Ayumi; Takeuchi, Ken

2014-01-01

A relational database management system (RDBMS) is designed based on NAND flash solid-state drive (SSD) for storage. By vertically integrating the storage engine (SE) and the flash translation layer (FTL), system performance is maximized and the internal SSD overhead is minimized. The proposed RDBMS SE utilizes physical information about the NAND flash memory which is supplied from the FTL. The query operation is also optimized for SSD. By these treatments, page-copy-less garbage collection is achieved and data fragmentation in the NAND flash memory is suppressed. As a result, RDBMS performance increases by 3.8 times, power consumption of SSD decreases by 46% and SSD life time is increased by 61%. The effectiveness of the proposed scheme increases with larger erase block sizes, which matches the future scaling trend of three-dimensional (3D-) NAND flash memories. The preferable row data size of the proposed scheme is below 500 byte for 16 kbyte page size.

System and method for conditioning a hardwood pulp liquid hydrolysate

DOEpatents

Waite, Darrell M; Arnold, Richard; St. Pierre, James; Pendse, Hemant P; Ceckler, William H

2013-12-17

A system and method for hardwood pulp liquid hydrolysate conditioning includes a first evaporator receives a hardwood mix extract and outputting a quantity of vapor and extract. A hydrolysis unit receives the extract, hyrolyzes and outputs to a lignin separation device, which separates and recovers a quantity of lignin. A neutralization device receives extract from the lignin separation device and a neutralizing agent, producing a mixture of solid precipitate and a fifth extract. The solid precipitate is removed from the fifth extract. A second evaporator removes a quantity of acid from the fifth extract in a vapor form. This vapor may be recycled to improve total acid recovery or discarded. A desalination device receives the diluted extract, separates out some of the acid and salt and outputs a desalinated solution.

An experimental study of solar desalination using free jets and an auxiliary hot air stream

NASA Astrophysics Data System (ADS)

Eid, Eldesouki I.; Khalaf-Allah, Reda A.; Dahab, Mohamed A.

2018-04-01

An experimental study for a solar desalination system based on jet-humidification with an auxiliary perpendicular hot air stream was carried out at Suez city, Egypt 29.9668°N, 32.5498°E. The tests were done from May to October 2016. The effects of nozzles situations and nozzle diameter with and without hot air stream on fresh water productivity were monitored. The results show that; the lateral and downward jets from narrow nozzles have more productivities than other situations. The hot air stream has to be adapted at a certain flow rate to get high values of productivity. The system productivity is (5.6 L/m 2 ), the estimated cost is (0.030063 / L) and the efficiency is 32.8%.

Solar energy water desalination in the United States and Saudi Arabia

NASA Technical Reports Server (NTRS)

Luft, W.; William, J.

1981-01-01

Five solar energy water desalination systems were designed to deliver 6000 cubic m/day of desalted water from either seawater or brackish water. Two systems will be selected for pilot plant construction. The pilot plants will have capacities in the range of 100 to 400 m/day. Goals of the Project Agreement for Cooperation in the Field of Solar Energy, under the auspices of the United States-Saudi Arabian Joint Commission on Economic Cooperation, are to: (1) cooperate in the field of solar energy technology for the mutual benefit of the two countries, including the development and stimulation of solar industries within the two countries; (2) advance the development of solar energy technology in the two countries; and (3) facilitate the transfer between the two countries of technology developed under this agreement.

Bioluminescence-Based Method for Measuring Assimilable Organic Carbon in Pretreatment Water for Reverse Osmosis Membrane Desalination ▿

PubMed Central

Weinrich, Lauren A.; Schneider, Orren D.; LeChevallier, Mark W.

2011-01-01

A bioluminescence-based assimilable organic carbon (AOC) test was developed for determining the biological growth potential of seawater within the reverse osmosis desalination pretreatment process. The test uses Vibrio harveyi, a marine organism that exhibits constitutive luminescence and is nutritionally robust. AOC was measured in both a pilot plant and a full-scale desalination plant pretreatment. PMID:21148685

A Comprehensive Study on Energy Efficiency and Performance of Flash-based SSD

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

Park, Seon-Yeon; Kim, Youngjae; Urgaonkar, Bhuvan

2011-01-01

Use of flash memory as a storage medium is becoming popular in diverse computing environments. However, because of differences in interface, flash memory requires a hard-disk-emulation layer, called FTL (flash translation layer). Although the FTL enables flash memory storages to replace conventional hard disks, it induces significant computational and space overhead. Despite the low power consumption of flash memory, this overhead leads to significant power consumption in an overall storage system. In this paper, we analyze the characteristics of flash-based storage devices from the viewpoint of power consumption and energy efficiency by using various methodologies. First, we utilize simulation tomore » investigate the interior operation of flash-based storage of flash-based storages. Subsequently, we measure the performance and energy efficiency of commodity flash-based SSDs by using microbenchmarks to identify the block-device level characteristics and macrobenchmarks to reveal their filesystem level characteristics.« less

A Hydrocarbon Fuel Flash Vaporization System for a Pulsed Detonation Engine

DTIC Science & Technology

2006-12-01

Experiments were performed in the Air Force Research Laboratory (AFRL) Pulsed Detonation Research Facility at Wright Patterson AFB, Ohio. The PDE ...AFRL-MN-EG-TP-2006-7420 A HYDROCARBON FUEL FLASH VAPORIZATION SYSTEM FOR A PULSED DETONATION ENGINE (PREPRINT) K. Colin Tucker...85,7<&/$66,),&$7,212) E7(/(3+21(180%(5 ,QFOXGHDUHDFRGH A Hydrocarbon Fuel Flash Vaporization System for a Pulsed Detonation Engine K

ROOFER Inventory Procedures and Inspection Manual for Metal Panel Roofing

DTIC Science & Technology

2012-12-01

impedes drainage . 2. Flashing has holes. 3. Flashing joint has failed and is allowing water to penetrate the roofing system . 4. Flashing flange... system shares a number of general characteristics with other types, but they use certain distinct types of materials that have their own... System . DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does

Improving the performance of water desalination through ultra-permeable functionalized nanoporous graphene oxide membrane

NASA Astrophysics Data System (ADS)

Hosseini, Mostafa; Azamat, Jafar; Erfan-Niya, Hamid

2018-01-01

Molecular dynamics simulations were performed to investigate the water desalination performance of nanoporous graphene oxide (NPGO) membranes. The simulated systems consist of a NPGO as a membrane with a functionalized pore in its center immersed in an aqueous ionic solution and a graphene sheet as a barrier. The considered NPGO membranes are involved four types of pore with different size and chemistry. The results indicated that the NPGO membrane has effective efficiency in salt rejection as well as high performance in water flux. For all types of pore with the radius size of 2.9-4.5 Å, the NPGO shows salt rejection of >89%. Functional groups on the surface and edge of pores have a great effect on water flux. To precisely understand the effect of functional groups on the surface of nanostructured membranes, nanoporous graphene was simulated under the same condition for comparison. Hydrophilic groups on the surface make the NPGO as an ultra-permeable membrane. As a result, the obtained water flux for NPGO was about 77% greater than graphene. Also, it was found that the water flux of NPGO is 2-5 orders of magnitude greater than other existing reverse osmosis membranes. Therefore, the investigated systems can be recommended as a model for the water desalination.

Energy efficiency of batch and semi-batch (CCRO) reverse osmosis desalination.

PubMed

Warsinger, David M; Tow, Emily W; Nayar, Kishor G; Maswadeh, Laith A; Lienhard V, John H

2016-12-01

As reverse osmosis (RO) desalination capacity increases worldwide, the need to reduce its specific energy consumption becomes more urgent. In addition to the incremental changes attainable with improved components such as membranes and pumps, more significant reduction of energy consumption can be achieved through time-varying RO processes including semi-batch processes such as closed-circuit reverse osmosis (CCRO) and fully-batch processes that have not yet been commercialized or modelled in detail. In this study, numerical models of the energy consumption of batch RO (BRO), CCRO, and the standard continuous RO process are detailed. Two new energy-efficient configurations of batch RO are analyzed. Batch systems use significantly less energy than continuous RO over a wide range of recovery ratios and source water salinities. Relative to continuous RO, models predict that CCRO and batch RO demonstrate up to 37% and 64% energy savings, respectively, for brackish water desalination at high water recovery. For batch RO and CCRO, the primary reductions in energy use stem from atmospheric pressure brine discharge and reduced streamwise variation in driving pressure. Fully-batch systems further reduce energy consumption by not mixing streams of different concentrations, which CCRO does. These results demonstrate that time-varying processes can significantly raise RO energy efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

An arduino based control system for a brackish water desalination plant

NASA Astrophysics Data System (ADS)

Caraballo, Ginna

Water scarcity for agriculture is one of the most important challenges to improve food security worldwide. In this thesis we study the potential to develop a low-cost controller for a small scale brackish desalination plant that consists of proven water treatment technologies, reverse osmosis, cation exchange, and nanofiltration to treat groundwater into two final products: drinking water and irrigation water. The plant is powered by a combination of wind and solar power systems. The low-cost controller uses Arduino Mega, and Arduino DUE, which consist of ATmega2560 and Atmel SAM3X8E ARM Cortex-M3 CPU microcontrollers. These are widely used systems characterized for good performance and low cost. However, Arduino also requires drivers and interfaces to allow the control and monitoring of sensors and actuators. The thesis explains the process, as well as the hardware and software implemented.

Active Flash: Out-of-core Data Analytics on Flash Storage

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

Boboila, Simona; Kim, Youngjae; Vazhkudai, Sudharshan S

2012-01-01

Next generation science will increasingly come to rely on the ability to perform efficient, on-the-fly analytics of data generated by high-performance computing (HPC) simulations, modeling complex physical phenomena. Scientific computing workflows are stymied by the traditional chaining of simulation and data analysis, creating multiple rounds of redundant reads and writes to the storage system, which grows in cost with the ever-increasing gap between compute and storage speeds in HPC clusters. Recent HPC acquisitions have introduced compute node-local flash storage as a means to alleviate this I/O bottleneck. We propose a novel approach, Active Flash, to expedite data analysis pipelines bymore » migrating to the location of the data, the flash device itself. We argue that Active Flash has the potential to enable true out-of-core data analytics by freeing up both the compute core and the associated main memory. By performing analysis locally, dependence on limited bandwidth to a central storage system is reduced, while allowing this analysis to proceed in parallel with the main application. In addition, offloading work from the host to the more power-efficient controller reduces peak system power usage, which is already in the megawatt range and poses a major barrier to HPC system scalability. We propose an architecture for Active Flash, explore energy and performance trade-offs in moving computation from host to storage, demonstrate the ability of appropriate embedded controllers to perform data analysis and reduction tasks at speeds sufficient for this application, and present a simulation study of Active Flash scheduling policies. These results show the viability of the Active Flash model, and its capability to potentially have a transformative impact on scientific data analysis.« less

Iron and copper release in drinking-water distribution systems.

PubMed

Shi, Baoyou; Taylor, James S

2007-09-01

A large-scale pilot study was carried out to evaluate the impacts of changes in water source and treatment process on iron and copper release in water distribution systems. Finished surface waters, groundwaters, and desalinated waters were produced with seven different treatment systems and supplied to 18 pipe distribution systems (PDSs). The major water treatment processes included lime softening, ferric sulfate coagulation, reverse osmosis, nanofiltration, and integrated membrane systems. PDSs were constructed from PVC, lined cast iron, unlined cast iron, and galvanized pipes. Copper pipe loops were set up for corrosion monitoring. Results showed that surface water after ferric sulfate coagulation had low alkalinity and high sulfates, and consequently caused the highest iron release. Finished groundwater treated by conventional method produced the lowest iron release but the highest copper release. The iron release of desalinated water was relatively high because of the water's high chloride level and low alkalinity. Both iron and copper release behaviors were influenced by temperature.

Circulating interleukin-8 and tumor necrosis factor-α are associated with hot flashes in healthy postmenopausal women.

PubMed

Huang, Wan-Yu; Hsin, I-Lun; Chen, Dar-Ren; Chang, Chia-Chu; Kor, Chew-Teng; Chen, Ting-Yu; Wu, Hung-Ming

2017-01-01

Hot flashes have been postulated to be linked to systemic inflammation. This study aimed to investigate the relationship between hot flashes, pro-inflammatory factors, and leukocytes in healthy, non-obese postmenopausal women. In this cross-sectional study, a total of 202 women aged 45-60 years were stratified into one of four groups according to their hot-flash status: never experienced hot flashes (Group N), mild hot flashes (Group m), moderate hot flashes (Group M), and severe hot flashes (Group S). Variables measured in this study included clinical parameters, hot flash experience, leukocytes, and fasting plasma levels of nine circulating cytokines/chemokines measured by using multiplex assays. Multiple linear regression analysis was used to evaluate the associations of hot flashes with these pro-inflammatory factors. The study was performed in a hospital medical center. The mean values of leukocyte number were not different between these four groups. The hot flash status had a positive tendency toward increased levels of circulating IL-6 (P-trend = 0.049), IL-8 (P-trend < 0.001), TNF-α (P-trend = 0.008), and MIP1β (P-trend = 0.04). Multivariate linear regression analysis revealed that hot-flash severity was significantly associated with IL-8 (P-trend < 0.001) and TNFα (P-trend = 0.007) among these nine cytokines/chemokines after adjustment for age, menopausal duration, BMI and FSH. Multivariate analysis further revealed that severe hot flashes were strongly associated with a higher IL-8 (% difference, 37.19%; 95% confidence interval, 14.98,63.69; P < 0.001) and TNFα (51.27%; 6.64,114.57; P < 0.05). The present study provides evidence that hot flashes are associated with circulating IL-8 and TNF-α in healthy postmenopausal women. It suggests that hot flashes might be related to low-grade systemic inflammation.

Circulating interleukin-8 and tumor necrosis factor-α are associated with hot flashes in healthy postmenopausal women

PubMed Central

Huang, Wan-Yu; Hsin, I-Lun; Chen, Dar-Ren; Chang, Chia-Chu; Kor, Chew-Teng; Chen, Ting-Yu

2017-01-01

Introduction Hot flashes have been postulated to be linked to systemic inflammation. This study aimed to investigate the relationship between hot flashes, pro-inflammatory factors, and leukocytes in healthy, non-obese postmenopausal women. Participants and design In this cross-sectional study, a total of 202 women aged 45–60 years were stratified into one of four groups according to their hot-flash status: never experienced hot flashes (Group N), mild hot flashes (Group m), moderate hot flashes (Group M), and severe hot flashes (Group S). Variables measured in this study included clinical parameters, hot flash experience, leukocytes, and fasting plasma levels of nine circulating cytokines/chemokines measured by using multiplex assays. Multiple linear regression analysis was used to evaluate the associations of hot flashes with these pro-inflammatory factors. Settings The study was performed in a hospital medical center. Results The mean values of leukocyte number were not different between these four groups. The hot flash status had a positive tendency toward increased levels of circulating IL-6 (P-trend = 0.049), IL-8 (P-trend < 0.001), TNF-α (P-trend = 0.008), and MIP1β (P-trend = 0.04). Multivariate linear regression analysis revealed that hot-flash severity was significantly associated with IL-8 (P-trend < 0.001) and TNFα (P-trend = 0.007) among these nine cytokines/chemokines after adjustment for age, menopausal duration, BMI and FSH. Multivariate analysis further revealed that severe hot flashes were strongly associated with a higher IL-8 (% difference, 37.19%; 95% confidence interval, 14.98,63.69; P < 0.001) and TNFα (51.27%; 6.64,114.57; P < 0.05). Conclusion The present study provides evidence that hot flashes are associated with circulating IL-8 and TNF-α in healthy postmenopausal women. It suggests that hot flashes might be related to low-grade systemic inflammation. PMID:28846735

Treatment and desalination of domestic wastewater for water reuse in a four-chamber microbial desalination cell.

PubMed

Lu, Yaobin; Abu-Reesh, Ibrahim M; He, Zhen

2016-09-01

Microbial desalination cells (MDCs) have been studied for contaminant removal from wastewater and salinity reduction in saline water. However, in an MDC wastewater treatment and desalination occurs in different streams, and high salinity of the treated wastewater creates challenges for wastewater reuse. Herein, a single-stream MDC (SMDC) with four chambers was developed for simultaneous organic removal and desalination in the same synthetic wastewater. This SMDC could achieve a desalination rate of 12.2-31.5 mg L(-1) h(-1) and remove more than 90 % of the organics and 75 % of NH4 (+)-N; the pH imbalance between the anode and cathode chambers was also reduced. Several strategies such as controlling catholyte pH, increasing influent COD concentration, adopting the batch mode, applying external voltage, and increasing the alkalinity of wastewater were investigated for improving the SMDC performance. Under a condition of 0.4 V external voltage, anolyte pH adjustment, and a batch mode, the SMDC decreased the wastewater salinity from 1.45 to below 0.75 mS cm(-1), which met the salinity standard of wastewater for irrigation. Those results encourage further development of the SMDC technology for sustainable wastewater treatment and reuse.

Online PH measurement technique in seawater desalination

NASA Astrophysics Data System (ADS)

Wang, Haibo; Wu, Kaihua; Hu, Shaopeng

2009-11-01

The measurement technology of pH is essential in seawater desalination. Glass electrode is the main pH sensor in seawater desalination. Because the internal impedance of glass electrode is high and the signal of pH sensor is easy to be disturbed, a signal processing circuit with high input impedance was designed. Because of high salinity of seawater and the characteristic of glass electrode, ultrasonic cleaning technology was used to online clean pH sensor. Temperature compensation was also designed to reduce the measurement error caused by variety of environment temperature. Additionally, the potential drift of pH sensor was analyzed and an automatic calibration method was proposed. In order to online monitor the variety of pH in seawater desalination, three operating modes were designed. The three modes are online monitoring mode, ultrasonic cleaning mode and auto-calibration mode. The current pH in seawater desalination was measured and displayed in online monitoring mode. The cleaning process of pH sensor was done in ultrasonic cleaning mode. The calibration of pH sensor was finished in auto-calibration mode. The result of experiments showed that the measurement technology of pH could meet the technical requirements for desalination. The glass electrode could be promptly and online cleaned and its service life was lengthened greatly.

Simultaneous Removal of Phenol and Dissolved Solids from Wastewater Using Multichambered Microbial Desalination Cell.

PubMed

Pradhan, Harapriya; Jain, Sumat Chand; Ghangrekar, Makarand M

2015-12-01

Microbial desalination cell (MDC) has great potential toward direct electricity generation from wastewater and concurrent desalination through potential difference developed due to microbial activity. Degradation of phenol by isolate Pseudomonas aeruginosa in anodic chamber and simultaneous desalination of water in middle desalination chamber of multichamber MDC is demonstrated in this study. Performance of the MDCs with different anodic inoculum conditions, namely pure culture of P. aeruginosa (MDC-1), 50 % v/v mixture of P. aeruginosa and anaerobic mixed consortia (MDC-2) and anaerobic mixed consortia (MDC-3), was evaluated to compare the phenol degradation in anodic chamber, bioelectricity generation, and simultaneous total dissolved solids (TDS) removal from saline water in desalination chamber. Synergistic effect between P. aeruginosa and mixed anaerobic consortia as inoculum was evident in MDC-2 demonstrating phenol degradation of 90 %, TDS removal of 75 % in 72 h of reaction time along with higher power generation of 27.5 mW/m(2) as compared to MDC-1 (95 %, 64 %, 12.8 mW/m(2), respectively) and MDC-3 (58 %, 52 %, 4.8 mW/m(2), respectively). The results illustrate that the multichamber MDC-2 is effective for simultaneous removal of phenol and dissolved solids contained in industrial wastewaters.

Self-Driven Desalination and Advanced Treatment of Wastewater in a Modularized Filtration Air Cathode Microbial Desalination Cell.

PubMed

Zuo, Kuichang; Wang, Zhen; Chen, Xi; Zhang, Xiaoyuan; Zuo, Jiaolan; Liang, Peng; Huang, Xia

2016-07-05

Microbial desalination cells (MDCs) extract organic energy from wastewater for in situ desalination of saline water. However, to desalinate salt water, traditional MDCs often require an anolyte (wastewater) and a catholyte (other synthetic water) to produce electricity. Correspondingly, the traditional MDCs also produced anode effluent and cathode effluent, and may produce a concentrate solution, resulting in a low production of diluate. In this study, nitrogen-doped carbon nanotube membranes and Pt carbon cloths were utilized as filtration material and cathode to fabricate a modularized filtration air cathode MDC (F-MDC). With real wastewater flowing from anode to cathode, and finally to the middle membrane stack, the diluate volume production reached 82.4%, with the removal efficiency of salinity and chemical oxygen demand (COD) reached 93.6% and 97.3% respectively. The final diluate conductivity was 68 ± 12 μS/cm, and the turbidity was 0.41 NTU, which were sufficient for boiler supplementary or industrial cooling. The concentrate production was only 17.6%, and almost all the phosphorus and salt, and most of the nitrogen were recovered, potentially allowing the recovery of nutrients and other chemicals. These results show the potential utility of the modularized F-MDC in the application of municipal wastewater advanced treatment and self-driven desalination.

Menopausal hot flashes: Randomness or rhythmicity

NASA Astrophysics Data System (ADS)

Kronenberg, Fredi

1991-10-01

Menopausal hot flashes are episodes of flushing, increased heart rate, skin blood flow and skin temperature, and a sensation of heat. The thermoregulatory and cardiovascular concomitants of hot flashes are associated with peaks in the levels of various hormones and neurotransmitters in the peripheral circulation. Although hot flashes affect about 75% of women, and are the primary reason that women at menopause seek medical attention, the mechanism of hot flashes is still not understood. Hot flashes vary in frequency and intensity both within and between individuals, and have been thought of as occurring randomly. Yet, some women report that their hot flashes are worse at a particular time of day or year. Initial examination of subjects' recordings of their hot flashes showed diurnal patterns of hot flash occurrence. There also seems to be a diurnal rhythm of hot flash intensity. Continuous physiological monitoring of hot flashes is facilitating the analysis of these patterns, which is revealing circadian and ultradian periodicities. The occurrence of hot flashes can be modulated by external and internal factors, including ambient temperature and fever. Rhythms of thermoregulatory and endocrine functions also may influence hot flash patterns. Examination of the interrelationships between the various systems of the body involved in hot flashes, and a multidisciplinary approach to the analysis of hot flash patterns, will aid our understanding of this complex phenomenon.

Small SWAP 3D imaging flash ladar for small tactical unmanned air systems

NASA Astrophysics Data System (ADS)

Bird, Alan; Anderson, Scott A.; Wojcik, Michael; Budge, Scott E.

2015-05-01

The Space Dynamics Laboratory (SDL), working with Naval Research Laboratory (NRL) and industry leaders Advanced Scientific Concepts (ASC) and Hood Technology Corporation, has developed a small SWAP (size, weight, and power) 3D imaging flash ladar (LAser Detection And Ranging) sensor system concept design for small tactical unmanned air systems (STUAS). The design utilizes an ASC 3D flash ladar camera and laser in a Hood Technology gyro-stabilized gimbal system. The design is an autonomous, intelligent, geo-aware sensor system that supplies real-time 3D terrain and target images. Flash ladar and visible camera data are processed at the sensor using a custom digitizer/frame grabber with compression. Mounted in the aft housing are power, controls, processing computers, and GPS/INS. The onboard processor controls pointing and handles image data, detection algorithms and queuing. The small SWAP 3D imaging flash ladar sensor system generates georeferenced terrain and target images with a low probability of false return and <10 cm range accuracy through foliage in real-time. The 3D imaging flash ladar is designed for a STUAS with a complete system SWAP estimate of <9 kg, <0.2 m3 and <350 W power. The system is modeled using LadarSIM, a MATLAB® and Simulink®- based ladar system simulator designed and developed by the Center for Advanced Imaging Ladar (CAIL) at Utah State University. We will present the concept design and modeled performance predictions.

An Interactive Computer Tool for Teaching About Desalination and Managing Water Demand in the US

NASA Astrophysics Data System (ADS)

Ziolkowska, J. R.; Reyes, R.

2016-12-01

This paper presents an interactive tool to geospatially and temporally analyze desalination developments and trends in the US in the time span 1950-2013, its current contribution to satisfying water demands and its future potentials. The computer tool is open access and can be used by any user with Internet connection, thus facilitating interactive learning about water resources. The tool can also be used by stakeholders and policy makers for decision-making support and with designing sustainable water management strategies. Desalination technology has been acknowledged as a solution to a sustainable water demand management stemming from many sectors, including municipalities, industry, agriculture, power generation, and other users. Desalination has been applied successfully in the US and many countries around the world since 1950s. As of 2013, around 1,336 desalination plants were operating in the US alone, with a daily production capacity of 2 BGD (billion gallons per day) (GWI, 2013). Despite a steady increase in the number of new desalination plants and growing production capacity, in many regions, the costs of desalination are still prohibitive. At the same time, the technology offers a tremendous potential for `enormous supply expansion that exceeds all likely demands' (Chowdhury et al., 2013). The model and tool are based on data from Global Water Intelligence (GWI, 2013). The analysis shows that more than 90% of all the plants in the US are small-scale plants with the capacity below 4.31 MGD. Most of the plants (and especially larger plants) are located on the US East Coast, as well as in California, Texas, Oklahoma, and Florida. The models and the tool provide information about economic feasibility of potential new desalination plants based on the access to feed water, energy sources, water demand, and experiences of other plants in that region.

Nanofiltration technology in water treatment and reuse: applications and costs.

PubMed

Shahmansouri, Arash; Bellona, Christopher

2015-01-01

Nanofiltration (NF) is a relatively recent development in membrane technology with characteristics that fall between ultrafiltration and reverse osmosis (RO). While RO membranes dominate the seawater desalination industry, NF is employed in a variety of water and wastewater treatment and industrial applications for the selective removal of ions and organic substances, as well as certain niche seawater desalination applications. The purpose of this study was to review the application of NF membranes in the water and wastewater industry including water softening and color removal, industrial wastewater treatment, water reuse, and desalination. Basic economic analyses were also performed to compare the profitability of using NF membranes over alternative processes. Although any detailed cost estimation is hampered by some uncertainty (e.g. applicability of estimation methods to large-scale systems, labor costs in different areas of the world), NF was found to be a cost-effective technology for certain investigated applications. The selection of NF over other treatment technologies, however, is dependent on several factors including pretreatment requirements, influent water quality, treatment facility capacity, and treatment goals.

Heavy metal contamination in sand and sediments near to disposal site of reject brine from desalination plant, Arabian Gulf: Assessment of environmental pollution.

PubMed

Alshahri, Fatimh

2017-01-01

Accumulation of heavy metals in environment may cause series potential risk in the living system. This study was carried out to investigate heavy metal contamination in sand samples and sediments along the beach near to disposal site of reject brine from Alkhobar desalination plant, which is one of the oldest and largest reverse osmosis desalination plants in eastern Saudi Arabia, Arabian Gulf. Fourteen heavy metals (U, Ca, Fe, Al, Ti, Sr, Rb, Ni, Pb, Cd, Cr, Cu, As, and Zr) were measured using gamma-ray spectrometry, atomic absorption spectrometer (AAS) and energy dispersive X-ray fluorescence spectrometer (EDX). The obtained data revealed that the concentrations of these metals were higher than the values in sediment and soil for other studies in Arabian Gulf. Furthermore, the mean values of Fe, Mn, Cr, Cu, As, Sr, and Zr concentrations in sand and sediments were higher than the geochemical background values in shale. The contamination factor (CF), modified degree of contamination (mC d ) and pollution load index (PLI) were assessed. According to contamination factors (CF > 1), the results showed elevated levels of Cu, Cr, Mn, Zr, and As in all samples. The highest value of contamination factor was found for As. Based on PLI (PLI > 1), the values of all sampling sites indicate a localized pollution in the study area. Current study could be useful as baseline data for heavy metals in sand and sediments nearby a desalination plant.

Geophysical characterization of subaerial hydrothermal manifestations in Punta Banda, Baja California, Mexico.

NASA Astrophysics Data System (ADS)

Flores-Marquez, L.; Prol-Ledesma, R. M.; Arango, C.; Canet, C.

2009-04-01

Important growth of population in Baja California Peninsula has triggered the need for energy and fresh water. The most sustainable possibility for increasing the availability of fresh water is the use of renewable energy sources in desalination plants. The abundance of geothermal manifestations in the peninsula provides a reliable energy source for desalination purposes. Geothermal development of the Baja California Peninsula dates from the 70's, when the Cerro Prieto geothermal field started producing electricity. Two important cities, Tijuana and Ensenada, are located in the north-western area of Baja California. The city of Ensenada has a desalination plant that is due to be replaced and the geothermal resources of the area could be an option for the new desalination plant. Punta Banda, a region near Ensenada, was specially investigated to determine its geothermal potential. Subaerial springs and the submarine vents were sampled and studied in this work, also geological and geochemical studies were performed, moreover geoelectrical surveys were accomplished to characterize the hydrothermal system at depth. Even though saline intrusion is a severe problem in Ensenada (TDS higher than 3000), thermal springs away from the coast and coastal springs have salinities lower than sea water. According to the geoelectrical models obtained from profiles, the inferred conductive features can be related to thermal anomalies. The existence of hot springs located along a trend suggests that the dynamic of the thermal fluid is restricted by secondary faults.

Organic flash cycles for efficient power production

DOEpatents

Ho, Tony; Mao, Samuel S.; Greif, Ralph

2016-03-15

This disclosure provides systems, methods, and apparatus related to an Organic Flash Cycle (OFC). In one aspect, a modified OFC system includes a pump, a heat exchanger, a flash evaporator, a high pressure turbine, a throttling valve, a mixer, a low pressure turbine, and a condenser. The heat exchanger is coupled to an outlet of the pump. The flash evaporator is coupled to an outlet of the heat exchanger. The high pressure turbine is coupled to a vapor outlet of the flash evaporator. The throttling valve is coupled to a liquid outlet of the flash evaporator. The mixer is coupled to an outlet of the throttling valve and to an outlet of the high pressure turbine. The low pressure turbine is coupled to an outlet of the mixer. The condenser is coupled to an outlet of the low pressure turbine and to an inlet of the pump.

Energy Implications of Seawater Desalination (Invited)

NASA Astrophysics Data System (ADS)

Cooley, H.; Heberger, M. G.

2013-12-01

Freshwater has traditionally come from rivers, lakes, streams, and groundwater aquifers. As demand increases and climate change alters the location and timing of water supply, these traditional sources are becoming unavailable, more difficult, or increasingly expensive to develop. As a result, many communities are switching to alternative sources of water. Interest in pursuing seawater desalination is high in many coastal communities. In California, for example, 17 plants are proposed for development along the California coast and two in Mexico. Water managers are pursing desalination because is a local supply that can help diversify the water supply portfolio. Additionally, it is a reliable supply, which can be especially valuable during a drought. But removing the salt from seawater is an energy-intensive process that consumes more energy per gallon than most other water supply and treatment options. These energy requirements are key factors that will impact the extent and success of desalination in California. Energy requirements for seawater desalination average about 4.0 kWh per cubic meter (m3) of water produced. By comparison, the least energy-intensive options of local sources of groundwater and surface water require 0 - 0.90 kWh per m3; wastewater reuse, depending on treatment levels, may require from 0.26 - 2.2 kWh per m3. Beyond the electricity required for the desalination facility itself, producing any new source of water, including through desalination, increases the amount of energy required to deliver and use the water produced as well as collect, treat, and dispose of the wastewater generated. Energy is the largest single variable cost for a desalination plant, varying from one-third to more than one-half the cost of produced water. Building a desalination plant may reduce a water utility's exposure to water reliability risks at the added expense of an increase in exposure to energy price risk. In dependent on hydropower, electricity prices tend to rise during droughts, when runoff, and thus power production, is constrained and electricity demands are high. Additionally, electricity prices are projected to rise in many regions to maintain and replace aging transmission and distribution infrastructure, install advanced metering infrastructure, comply with once-through cooling regulations, meet new demand growth , and increase renewable energy production. While rising electricity prices will affect the price of all water sources, they will have a greater impact on those that are the most energy intensive, like desalination. The high energy requirements of seawater desalination also raise concerns about greenhouse gas emissions. In 2006, California lawmakers passed the Global Warming Solutions Act, or Assembly Bill 32, which requires the state to reduce greenhouse gas emissions to 1990 levels by 2020. Thus, the state has committed itself to a program of steadily reducing its greenhouse gas emissions in both the short- and long-term, which includes cutting current emissions and preventing future emissions associated with growth. Desalination - through increased energy use - can cause an increase in greenhouse gas emissions, further contributing to the root cause of climate change and running counter to the state's greenhouse gas reduction goals.

Technology of uncooled fast polycrystalline PbSe focal plane arrays in systems for muzzle flash detection

NASA Astrophysics Data System (ADS)

Kastek, Mariusz; PiÄ tkowski, Tadeusz; Polakowski, Henryk; Barela, Jaroslaw; Firmanty, Krzysztof; Trzaskawka, Piotr; Vergara, German; Linares, Rodrigo; Gutierrez, Raul; Fernandez, Carlos; Montojo Supervielle, Maria Teresa

2014-05-01

The paper presents some aspects of muzzle flash detection using low resolution polycrystalline PbSe 32×32 and 80×80 detectors FPA operating at room temperature (uncooled performance). These sensors, which detect in MWIR (3 - 5 microns region) and are manufactured using proprietary technology from New Infrared Technologies (VPD PbSe - Vapor Phase Deposition of polycrystalline PbSe), can be applied to muzzle flash detection. The system based in the uncooled 80×80 FPA monolithically integrated with the CMOS readout circuitry has allowed image recording with frame rates over 2000 Hz (true snapshot acquisition), whereas the lower density, uncooled 32×32 FPA is suitable for being used in low cost infrared imagers sensitive in the MWIR band with frame rates above 1000 Hz. The FPA detector, read-out electronics and processing electronics (allows the implementation of some algorithms for muzzle flash detection) of both systems are presented. The systems have been tested at field test ground. Results of detection range measurement with two types of optical systems (wide and narrow field of view) have been shown. The theoretical analysis of possibility detection of muzzle flash and initial results of testing of some algorithms for muzzle flash detection have been presented too.

Fast uncooled module 32×32 array of polycrystalline PbSe used for muzzle flash detection

NASA Astrophysics Data System (ADS)

Kastek, Mariusz; Dulski, Rafał; Trzaskawka, Piotr; Bieszczad, Grzegorz

2011-06-01

The paper presents some aspects of muzzle flash detection using low resolution polycrystalline PbSe uncooled 32×32 detectors array. This system for muzzle flash detection works in MWIR (3 - 5 microns) region and it is based on VPD (Vapor Phase Deposition) technology. The low density uncooled 32×32 array is suitable for being used in low cost IR imagers sensitive in the MWIR band with frame rates exceeding 1.000 Hz. The FPA detector, read-out electronics and processing electronics (allowing the implementation of some algorithms for muzzle flash detection) has been presented. The system has been tested at field test ground. Results of detection range measurement with two types of optical systems (wide and narrow field of view) have been shown. The initial results of testing of some algorithms for muzzle flash detection have been also presented.

Characteristics of the most intense lightning storm ever recorded at the CN Tower

NASA Astrophysics Data System (ADS)

Hussein, A. M.; Kazazi, S.; Anwar, M.; Yusouf, M.; Liatos, P.

2017-02-01

Lightning strikes to the CN Tower have been optically observed since 1978. In 1990, five independent systems started to operate to simultaneously record parameters of lightning strikes to the tower, including the time derivative of the current, the associated electric and magnetic fields, and the channel optical characteristics. On August 24, 2011, during an unusually severe lightning storm, video records showed that the CN Tower was struck with 52 lightning flashes within 84 min and 6.9 s. Thus, this storm produced, on average, a flash to the tower every 99 s. However, the CN Tower lightning current derivative measurement system only recorded 32 flashes, which were perfectly time-matched with 32 of the 52 video-recorded flashes. It is found that the current derivative measurement system recorded every video-recorded flash that contained at least one return stroke. Based on the analysis of video records, it is noted that each of the storm's 52 flashes contains an initial-stage current, proving that all flashes were upward initiated. This unique CN Tower storm - the most intense ever recorded at the tower - is here thoroughly analyzed, based on video and current records. The inter-flash time within the storm is found to vary between 10.6 s and 274 s, with an overall average of 98 s. It is also found that the inter-flash time between successive non-return-stroke flashes is on average 64% longer than that for successive flashes containing return strokes. Statistical analysis of video and current data clearly reveals that the time duration of flashes containing initial-stage currents and return strokes is on average 27% longer than that of flashes that only have initial-stage currents. Furthermore, it is important to note that the time duration of the initial-stage current in flashes containing no return strokes is on average 76% longer than that in flashes containing return strokes. Therefore, it is possible to conclude that if the time duration of the initial-stage current in a flash is long enough, resulting in large charge transfer, then there is less probability of having return strokes following it. The 32 current-recorded flashes contain a total of 156 return strokes, with an average multiplicity of 4.875. It is worth mentioning that during one decade, 1992-2001, the CN Tower current derivative measurement system only recorded 478 return strokes, demonstrating that the number of return strokes recorded at the tower within about 84 min is close to one third of those recorded at the tower during one decade. This finding clearly shows the great value and rarity of the presented extensive lightning current derivative data. Only one of the 32 current-recorded flashes is proved to be positive with a single return stroke. Based on current records, out of a total of 124 inter-stroke time intervals, 94% are found to be within 200 ms, with an overall inter-stroke time average of 68.1 ms. The maximum inter-stroke time recorded during this storm is 726.3 ms, the longest ever recorded at the CN Tower.

FLASH Interface; a GUI for managing runtime parameters in FLASH simulations

NASA Astrophysics Data System (ADS)

Walker, Christopher; Tzeferacos, Petros; Weide, Klaus; Lamb, Donald; Flocke, Norbert; Feister, Scott

2017-10-01

We present FLASH Interface, a novel graphical user interface (GUI) for managing runtime parameters in simulations performed with the FLASH code. FLASH Interface supports full text search of available parameters; provides descriptions of each parameter's role and function; allows for the filtering of parameters based on categories; performs input validation; and maintains all comments and non-parameter information already present in existing parameter files. The GUI can be used to edit existing parameter files or generate new ones. FLASH Interface is open source and was implemented with the Electron framework, making it available on Mac OSX, Windows, and Linux operating systems. The new interface lowers the entry barrier for new FLASH users and provides an easy-to-use tool for experienced FLASH simulators. U.S. Department of Energy (DOE), NNSA ASC/Alliances Center for Astrophysical Thermonuclear Flashes, U.S. DOE NNSA ASC through the Argonne Institute for Computing in Science, U.S. National Science Foundation.

Potential effects of desalinated water quality on the operation stability of wastewater treatment plants.

PubMed

Lew, Beni; Cochva, Malka; Lahav, Ori

2009-03-15

Desalinated water is expected to become the major source of drinking water in many places in the near future, and thus the major source of wastewater to arrive at wastewater treatment plants. The paper examines the effect of the alkalinity value with which the water is released from the desalination plant on the alkalinity value that would develop within the wastewater treatment process under various nitrification-denitrification operational scenarios. The main hypothesis was that the difference in the alkalinity value between tap water and domestic wastewater is almost exclusively a result of the hydrolysis of urea (NH(2)CONH(2), excreted in the human urine) to ammonia (NH(3)), regardless of the question what fraction of NH(3(aq)) is transformed to NH(4)(+). Results from a field study show that the ratio between the alkalinity added to tap water when raw wastewater is formed (in meq/l units) and the TAN (total ammonia nitrogen, mole/l) concentration in the raw wastewater is almost 1:1 in purely domestic sewage and close to 1:1 in domestic wastewater streams mixed with light industry wastewaters. Having established the relationship between TAN and total alkalinity in raw wastewater the paper examines three theoretical nitrification-denitrification treatment scenarios in the wastewater treatment plant (WWTP). The conclusion is that if low-alkalinity desalinated water constitutes the major water source arriving at the WWTP, external alkalinity will have to be added in order to avoid pH drop and maintain process stability. The results lead to the conclusion that supplying desalinated water with a high alkalinity value (e.g. > or =100 mg/l as CaCO(3)) would likely prevent the need to add costly basic chemicals in the WWTP, while, in addition, it would improve the chemical and biological stability of the drinking water in the distribution system.

System and method for conditioning a hardwood pulp liquid hydrolysate

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

Waite, Darrell; Arnold, Richard; St. Pierre, James

2015-06-30

A system and method for hardwood pulp liquid hydrolysate conditioning includes a first evaporator receives a hardwood mix extract and outputting a quantity of vapor and extract. A hydrolysis unit receives the extract, hydrolyzes and outputs to a lignin separation device, which separates and recovers a quantity of lignin. A neutralization device receives extract from the lignin separation device and a neutralizing agent, producing a mixture of solid precipitate and a fifth extract. The solid precipitate is removed from the fifth extract. A second evaporator removes a quantity of acid from the fifth extract in a vapor form. This vapormore » may be recycled to improve total acid recovery or discarded. A desalination device receives the diluted extract, separates out some of the acid and salt and outputs a desalinated solution.« less

Hybrid capacitive deionization with anion-exchange membranes for lithium extraction

NASA Astrophysics Data System (ADS)

Siekierka, Anna; Bryjak, Marek

2017-11-01

Lithium is considered to be a critical material for various industrial fields. We present our studies on extraction lithium from diluted aqueous solution by novel hybrid system based on a membrane capacitive deionization and batteries desalination. Hybrid CDI is comprised by a lithium selective adsorbent, activated carbon electrode and anion-exchange membranes. Here, we demonstrated implication of various type of anion-exchange membranes and influence their properties on effective capacity and energy requirements in charge/discharge steps. We described a configuration with anion-exchange membrane characterized by adsorption capacity of 35 mg/g of Li+ with 0.08Wh/g and removal efficiency of 60 % of lithium ions, using novel selective desalination technique.

Synoptic-scale atmospheric conditions associated with flash flooding in watersheds of the Catskill Mountains, New York, USA

NASA Astrophysics Data System (ADS)

Teale, N. G.; Quiring, S. M.

2015-12-01

Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.Understanding flash flooding is important in unfiltered watersheds, such as portions of the New York City water supply system (NYCWSS), as water quality is degraded by turbidity associated with flooding. To further understand flash flooding in watersheds of the NYCWSS, synoptic-scale atmospheric conditions most frequently associated with flash flooding between 1987 and 2013 were examined. Flash floods were identified during this time period using USGS 15-minute discharge data at the Esopus Creek near Allaben, NY and Neversink River at Claryville, NY gauges. Overall, 25 flash floods were detected, occurring over 17 separate flash flood days. These flash flood days were compared to the days on which flash flood warnings encompassing the study area was issued by the National Weather Service. The success rate for which the flash flood warnings for Ulster County coincided with flash flood in the study watershed was 0.09, demonstrating the highly localized nature of flash flooding in the Catskill Mountain region. The synoptic-scale atmospheric patterns influencing the study area were characterized by a principal component analysis and k-means clustering of NCEP/NCAR 500 mb geopotential height reanalysis data. This procedure was executed in Spatial Synoptic Typer Tools 4.0. While 17 unique synoptic patterns were identified, only 3 types were strongly associated with flash flooding events. A strong southwesterly flow suggesting advection of moisture from the Atlantic Ocean and Gulf of Mexico is shown in composites of these 3 types. This multiscalar study thereby links flash flooding in the NYCWSS with synoptic-scale atmospheric circulation.

Remote sensing of rainfall for flash flood prediction in the United States

NASA Astrophysics Data System (ADS)

Gourley, J. J.; Flamig, Z.; Vergara, H. J.; Clark, R. A.; Kirstetter, P.; Terti, G.; Hong, Y.; Howard, K.

2015-12-01

This presentation will briefly describe the Multi-Radar Multi-Sensor (MRMS) system that ingests all NEXRAD and Canadian weather radar data and produces accurate rainfall estimates at 1-km resolution every 2 min. This real-time system, which was recently transitioned for operational use in the National Weather Service, provides forcing to a suite of flash flood prediction tools. The Flooded Locations and Simulated Hydrographs (FLASH) project provides 6-hr forecasts of impending flash flooding across the US at the same 1-km grid cell resolution as the MRMS rainfall forcing. This presentation will describe the ensemble hydrologic modeling framework, provide an evaluation at gauged basins over a 10-year period, and show the FLASH tools' performance during the record-setting floods in Oklahoma and Texas in May and June 2015.

Competitive migration behaviors of multiple ions and their impacts on ion-exchange resin packed microbial desalination cell.

PubMed

Zuo, Kuichang; Yuan, Lulu; Wei, Jincheng; Liang, Peng; Huang, Xia

2013-10-01

Mixed ion-exchange resins packed microbial desalination cell (R-MDC) could stabilize the internal resistance, however, the impacts of multiple ions on R-MDC performance was unclear. This study investigated the desalination performance, multiple ions migration behaviors and their impacts on R-MDCs fed with salt solution containing multiple anions and cations. Results showed that R-MDC removed multiple anions better than multiple cations with desalination efficiency of 99% (effluent conductivity <0.05 ms/cm) at hydraulic retention time of 50 h. Competitive migration order was SO4(2-)>NO3(-)>Cl(-) for anions and Ca(2+)≈Mg(2+)>NH4(+)>Na(+) for cations, jointly affected by both their molar conductivity and exchange selectivity on resins. After long-term operation, the existence of higher concentration Ca(2+) and Mg(2+) caused the electric conductivity of mixed resins decrease and scaling on the surface of cation-exchange membrane adjoined with cathode chamber, suggesting that R-MDC would be more suitable for desalination of water with lower hardness. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ground- and Space-based Observations of Horizontally-extensive Lightning Flashes

NASA Astrophysics Data System (ADS)

Zhang, D.; Cummins, K. L.; Bitzer, P. M.

2017-12-01

Horizontally-extensive lightning flashes occur frequently in association with mature and late phases of multicellular thunderstorms, both in trailing stratiform regions and horizontally-extensive anvils. The spatial relationship between these flashes and the parent cloud volume is of importance for space launch operational decision making, and is of broader scientific interest. Before this question can be accurately addressed, there is a need to understand the degree to which current lightning observation systems can depict the spatial extent of these long flashes. In this ongoing work, we will intercompare the depiction of horizontally-extensive flashes using several ground-based lightning locating systems (LLSs) located at Kennedy Space Center (KSC) with space-based observations observed by the recently-launched Geostationary Lightning Mapper (GLM) onboard the GOES-16 satellite. Ground-based datasets include the KSC Lightning Mapping Array (KSCLMA), the operational narrowband digital interferometer network MERLIN, and the combined cloud-to-ground and cloud lightning dataset produced by the U.S. National Lightning Detection Network (NLDN). The KSCLMA system is a network of VHF time-of-arrival sensors that preferentially report breakdown processes, and MERLIN is a network of VHF interferometers that point to the discharges in the horizontal plane. Observations to date indicate that MERLIN and the KSCSLMA provide similar overall descriptions of the spatial and temporal extent of these flashes, while the NLDN does not provide adequate spatial mapping of these flashes. The KSC LMA system has much better location accuracy, and provides excellent 3-dimensional representation within 100 km of KSC. It also has sufficient sensitivity to provide 2-dimensional flash mapping within 250 km of KSC. The MERLIN system provides a more-detailed representation of fast leader propagation (in 2 dimensions) with 100 km of KSC. Earlier work during the CHUVA campaign in Brazil with similar systems and the (orbital) Lightning Imaging System (LIS) has shown that the interferometric data correlated much better in space and time with the LIS optical observations. We are currently investigating this relationship at KSC, where both the LMA and interferometer perform much better than the systems used during CHUVA.

The framework of a UAS-aided flash flood modeling system for coastal regions

NASA Astrophysics Data System (ADS)

Zhang, H.; Xu, H.

2016-02-01

Flash floods cause severe economic damage and are one of the leading causes of fatalities connected with natural disasters in the Gulf Coast region. Current flash flood modeling systems rely on empirical hydrological models driven by precipitation estimates only. Although precipitation is the driving factor for flash floods, soil moisture, urban drainage system and impervious surface have been recognized to have significant impacts on the development of flash floods. We propose a new flash flooding modeling system that integrates 3-D hydrological simulation with satellite and multi-UAS observations. It will have three advantages over existing modeling systems. First, it will incorporate 1-km soil moisture data through integrating satellite images from European SMOS mission and NASA's SMAP mission. The utilization of high-resolution satellite images will provide essential information to determine antecedent soil moisture condition, which is an essential control on flood generation. Second, this system is able to adjust flood forecasting based on real-time inundation information collected by multi-UAS. A group of UAS will be deployed during storm events to capture the changing extent of flooded areas and water depth at multiple critical locations simultaneously. Such information will be transmitted to a hydrological model to validate and improve flood simulation. Third, the backbone of this system is a state-of-the-art 3-D hydrological model that assimilates the hydrological information from satellites and multi-UAS. The model is able to address surface water-groundwater interactions and reflect the effects of various infrastructures. Using Web-GIS technologies, the modeling results will be available online as interactive flood maps accessible to the public. To support the development and verification of this modeling system, surface and subsurface hydrological observations will be conducted in a number of small watersheds in the Coastal Bend region. We envision this system will provide an innovative means to benefit the forecasting, evaluation and mitigation of flash floods in costal regions.

Flash signal evolution in Photinus fireflies: character displacement and signal exploitation in a visual communication system.

PubMed

Stanger-Hall, Kathrin F; Lloyd, James E

2015-03-01

Animal communication is an intriguing topic in evolutionary biology. In this comprehensive study of visual signal evolution, we used a phylogenetic approach to study the evolution of the flash communication system of North American fireflies. The North American firefly genus Photinus contains 35 described species with simple ON-OFF visual signals, and information on habitat types, sympatric congeners, and predators. This makes them an ideal study system to test hypotheses on the evolution of male and female visual signal traits. Our analysis of 34 Photinus species suggests two temporal pattern generators: one for flash duration and one for flash intervals. Reproductive character displacement was a main factor for signal divergence in male flash duration among sympatric Photinus species. Male flash pattern intervals (i.e., the duration of the dark periods between signals) were positively correlated with the number of sympatric Photuris fireflies, which include predators of Photinus. Females of different Photinus species differ in their response preferences to male traits. As in other communication systems, firefly male sexual signals seem to be a compromise between optimizing mating success (sexual selection) and minimizing predation risk (natural selection). An integrative model for Photinus signal evolution is proposed. © 2015 The Author(s).

Clinical value of Flash glucose monitoring in patients with type 1 diabetes treated with continuous subcutaneous insulin infusion.

PubMed

Moreno-Fernandez, Jesus; Pazos-Couselo, Marcos; González-Rodriguez, Maria; Rozas, Pedro; Delgado, Manuel; Aguirre, Miguel; Garcia-Lopez, Jose Manuel

2018-06-12

To analyze the clinical impact of the Flash glucose monitoring system in patients with type 1 diabetes mellitus (T1DM) treated with continuous subcutaneous insulin infusion (CSII). A 24-week retrospective cohort study in CSII-treated T1DM patients exposed (1:1) to the Flash glucose monitoring system vs. self-monitoring of capillary blood glucose (SMBG). The primary outcome was the difference in hemoglobin A1c (HbA1c) levels between both groups at the end of the study. Thirty-six patients with a mean age of 38.2 years (range 22-55) and a mean T1DM duration of 20.9±7.8 years, treated with CSII for 7.1±5.4 years, were enrolled into the study. At the end of the study, mean HbA1c levels improved in patients in the Flash group (7.1±0.7 vs. 7.8±1.0, p=0.04). Only the Flash group showed a significant decrease in HbA1c levels of -0.4% (95% CI, -0.6, -0.2; p=0.004) during follow-up. Flash patients captured 93.9% of data through 17.8±9.9 scans daily. In fact, the Flash cohort showed a three-fold increase in daily self-monitoring of glucose, while daily frequency of SMBG decreased during the study (-1.8 tests/24h (95% CI -3, -0.7; p=0.01). No safety issues related to Flash use were recorded. The Flash glucose monitoring system is a novel approach to improve blood glucose control in CSII-treated T1DM patients. Randomized controlled trials are needed to assess the effectiveness of this system in CSII-treated T1DM patients. Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

A novel multi-stage direct contact membrane distillation module: Design, experimental and theoretical approaches.

PubMed

Lee, Jung-Gil; Kim, Woo-Seung; Choi, June-Seok; Ghaffour, Noreddine; Kim, Young-Deuk

2016-12-15

An economic desalination system with a small scale and footprint for remote areas, which have a limited and inadequate water supply, insufficient water treatment and low infrastructure, is strongly demanded in the desalination markets. Here, a direct contact membrane distillation (DCMD) process has the simplest configuration and potentially the highest permeate flux among all of the possible MD processes. This process can also be easily instituted in a multi-stage manner for enhanced compactness, productivity, versatility and cost-effectiveness. In this study, an innovative, multi-stage, DCMD module under countercurrent-flow configuration is first designed and then investigate both theoretically and experimentally to identify its feasibility and operability for desalination application. Model predictions and measured data for mean permeate flux are compared and shown to be in good agreement. The effect of the number of module stages on the mean permeate flux, performance ratio and daily water production of the MDCMD system has been theoretically identified at inlet feed and permeate flow rates of 1.5 l/min and inlet feed and permeate temperatures of 70 °C and 25 °C, respectively. The daily water production of a three-stage DCMD module with a membrane area of 0.01 m 2  at each stage is found to be 21.5 kg. Copyright © 2016 Elsevier Ltd. All rights reserved.

All-season flash flood forecasting system for real-time operations

USDA-ARS?s Scientific Manuscript database

Flash floods can cause extensive damage to both life and property, especially because they are difficult to predict. Flash flood prediction requires high-resolution meteorologic observations and predictions, as well as calibrated hydrologic models in addition to extensive data handling. We have de...

Atomistic and continuum scale modeling of functionalized graphyne membranes for water desalination.

PubMed

Raju, Muralikrishna; Govindaraju, Pavan B; van Duin, Adri C T; Ihme, Matthias

2018-02-22

Recent theoretical and experimental studies reported ultra-high water permeability and salt rejection in nanoporous single-layer graphene. However, creating and controlling the size and distribution of nanometer-scale pores pose significant challenges to application of these membranes for water desalination. Graphyne and hydrogenated graphyne have tremendous potential as ultra-permeable membranes for desalination and wastewater reclamation due to their uniform pore-distribution, atomic thickness and mechano-chemical stability. Using molecular dynamics (MD) simulations and upscale continuum analysis, the desalination performance of bare and hydrogenated α-graphyne and γ-{2,3,4}-graphyne membranes is evaluated as a function of pore size, pore geometry, chemical functionalization and applied pressure. MD simulations show that pores ranging from 20 to 50 Å 2 reject in excess of 90% of the ions for pressures up to 1 GPa. Water permeability is found to range up to 85 L cm -2 day -1 MPa -1 , which is up to three orders of magnitude larger than commercial seawater reverse osmosis (RO) membranes and up to ten times that of nanoporous graphene. Pore chemistry, functionalization and geometry are shown to play a critical role in modulating the water flux, and these observations are explained by water velocity, density, and energy barriers in the pores. The atomistic scale investigations are complemented by upscale continuum analysis to examine the performance of these membranes in application to cross-flow RO systems. This upscale analysis, however, shows that the significant increase in permeability, observed from MD simulations, does not fully translate to current RO systems due to transport limitations. Nevertheless, upscale calculations predict that the higher permeability of graphyne membranes would allow up to six times higher permeate recovery or up to 6% less energy consumption as compared to thin-film composite membranes at currently accessible operating conditions. Significantly higher energy savings and permeate recovery can be achieved if higher feed-flow rates can be realized.

Desalination Brine Discharge Impacts on Coastal Biology and Water Chemistry - A Case Study from Carlsbad Southern California

NASA Astrophysics Data System (ADS)

Petersen, K. L.; Heck, N.; Potts, D. C.; Paytan, A.

2017-12-01

Fresh water demand is increasing world-wide due to on-going droughts, climate change and increasing human population and associated demand for food and water. Desalination of seawater is a reliable source of potable water; however the effects of byproduct brine discharge from desalination plants on coastal areas have not been thoroughly assessed. Here we report results from in-situmeasurements of the effects of brine discharge on water chemistry and coastal biology from a desalination plant in Carlsbad, Southern California. We compared select parameters in the coastal zone around the discharge site before and after operation began and conducted additional controlled laboratory incubations with key coastal species and brine effluent. Our in-situ data shows differences in salinity and temperature between the discharge area and a control site both before and after the desalination plant started operation. The discharge water is warmer by 3-5 Co than the ambient seawater and a temperature gradient is seen around the discharge channel. This is likely a result of mixing of the desalination brine with power plant cooling water for dilution prior to discharge and the higher temperatures are not directly attributed to the desalination. Our post-discharge results show a decipherable salinity plume at the bottom of the water column ( 6 m depth) reaching up to 600 m offshore from the discharge site. This indicates inefficient mixing of the brine in the coastal discharge zone. No significant differences are found in nutrient levels, organic carbon or chlorophyll a concentrations around the discharge. The benthic biology assemblage post-discharge is significantly different from the pre-discharge organisms' assemblage. However, the role of seasonal changes in temperature may also have impacted the data as the sampling was conducted during different seasons. Controlled incubation experiments of brittle stars (Ophiothrix spiculata) shows no significant difference in growth or survival rates when held in water collected at the discharge site ( 6% salinity increase of ambient) for 5 weeks. Our results signifies the importance of proper dilution of discharge brine at desalination plants and underlies the need for continuous monitoring around discharge areas to constrain the impacts on the coastal ecology.

Quasi-steady-state analysis of coupled flashing ratchets.

PubMed

Levien, Ethan; Bressloff, Paul C

2015-10-01

We perform a quasi-steady-state (QSS) reduction of a flashing ratchet to obtain a Brownian particle in an effective potential. The resulting system is analytically tractable and yet preserves essential dynamical features of the full model. We first use the QSS reduction to derive an explicit expression for the velocity of a simple two-state flashing ratchet. In particular, we determine the relationship between perturbations from detailed balance, which are encoded in the transitions rates of the flashing ratchet, and a tilted-periodic potential. We then perform a QSS analysis of a pair of elastically coupled flashing ratchets, which reduces to a Brownian particle moving in a two-dimensional vector field. We suggest that the fixed points of this vector field accurately approximate the metastable spatial locations of the coupled ratchets, which are, in general, impossible to identify from the full system.

Characterization of Resistances of a Capacitive Deionization System

DOE PAGES

Qu, Yatian; Baumann, Theodore F.; Santiago, Juan G.; ...

2015-07-27

Capacitive deionization (CDI) is a promising desalination technology, which operates at low pressure, low temperature, requires little infrastructure, and has the potential to consume less energy for brackish water desalination. However, CDI devices consume significantly more energy than the theoretical thermodynamic minimum, and this is at least partly due to resistive power dissipation. We here report our efforts to characterize electric resistances in a CDI system, with a focus on the resistance associated with the contact between current collectors and porous electrodes. We present an equivalent circuit model to describe resistive components in a CDI cell. We propose measurable figuresmore » of merit to characterize cell resistance. We also show that contact pressure between porous electrodes and current collectors can significantly reduce contact resistance. As a result, we propose and test an alternative electrical contact configuration which uses a pore-filling conductive adhesive (silver epoxy) and achieves significant reductions in contact resistance.« less

Integration of solar process heat into an existing thermal desalination plant in Qatar

NASA Astrophysics Data System (ADS)

Dieckmann, S.; Krishnamoorthy, G.; Aboumadi, M.; Pandian, Y.; Dersch, J.; Krüger, D.; Al-Rasheed, A. S.; Krüger, J.; Ottenburger, U.

2016-05-01

The water supply of many countries in the Middle East relies mainly on water desalination. In Qatar, the water network is completely fed with water from desalination plants. One of these power and desalination plants is located in Ras Abu Fontas, 20 km south of the capital Doha. The heat required for thermal desalination is provided by steam which is generated in waste heat recovery boilers (HRB) connected to gas turbines. Additionally, gas fired boilers or auxiliary firing in the HRBs are used in order to decouple the water generation from the electricity generation. In Ras Abu Fontas some auxiliary boilers run 24/7 because the HRB capacity does not match the demand of the desalination units. This paper contains the techno-economic analysis of two large-scale commercial solar field options, which could reduce the fuel consumption significantly. Both options employ parabolic trough technology with a nominal saturated steam output of 350 t/h at 15 bar (198°C, 240 MW). The first option uses direct steam generation without storage while the second relies on common thermal oil in combination with a molten salt thermal storage with 6 hours full-load capacity. The economic benefit of the integration of solar power depends mainly on the cost of the fossil alternative, and thus the price (respectively opportunity costs) of natural gas. At a natural gas price of 8 US-/MMBtu the internal rate of return on equity (IRR) is expected at about 5%.

Multi-Head Very High Power Strobe System For Motion Picture Special Effects

NASA Astrophysics Data System (ADS)

Lovoi, P. A.; Fink, Michael L.

1983-10-01

A very large camera synchronizable strobe system has been developed for motion picture special effects. This system, the largest ever built, was delivered to MGM/UA to be used in the movie "War Games". The system consists of 12 individual strobe heads and a power supply distribution system. Each strobe head operates independently and may be flashed up to 24 times per second under computer control. An energy of 480 Joules per flash is used in six strobe heads and 240 Joules per flash in the remaining six strobe heads. The beam pattern is rectangular with a FWHM of 60° x 48°.

Faradaic reactions in capacitive deionization (CDI) - problems and possibilities: A review.

PubMed

Zhang, Changyong; He, Di; Ma, Jinxing; Tang, Wangwang; Waite, T David

2018-01-01

Capacitive deionization (CDI) is considered to be one of the most promising technologies for the desalination of brackish water with low to medium salinity. In practical applications, Faradaic redox reactions occurring in CDI may have both negative and positive effects on CDI performance. In this review, we present an overview of the types and mechanisms of Faradaic reactions in CDI systems including anodic oxidation of carbon electrodes, cathodic reduction of oxygen and Faradaic ion storage and identify their apparent negative and positive effects on water desalination. A variety of strategies including development of novel electrode materials and use of alternative configurations and/or operational modes are proposed for the purpose of mitigation or elimination of the deterioration of electrodes and the formation of byproducts caused by undesired side Faradaic reactions. It is also recognized that Faradaic reactions facilitate a variety of exciting new applications including i) the incorporation of intercalation electrodes to enhance water desalination or to selectively separate certain ions through reversible Faradaic reactions and ii) the use of particular anodic oxidation and cathodic reduction reactions to realize functions such as water disinfection and contaminant removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel water filtration of saline water in the outermost layer of mangrove roots.

PubMed

Kim, Kiwoong; Seo, Eunseok; Chang, Suk-Kyu; Park, Tae Jung; Lee, Sang Joon

2016-02-05

The scarcity of fresh water is a global challenge faced at present. Several desalination methods have been suggested to secure fresh water from sea water. However, conventional methods suffer from technical limitations, such as high power consumption, expensive operating costs, and limited system durability. In this study, we examined the feasibility of using halophytes as a novel technology of desalinating high-concentration saline water for long periods. This study investigated the biophysical characteristics of sea water filtration in the roots of the mangrove Rhizophora stylosa from a plant hydrodynamic point of view. R. stylosa can grow even in saline water, and the salt level in its roots is regulated within a certain threshold value through filtration. The root possesses a hierarchical, triple layered pore structure in the epidermis, and most Na(+) ions are filtered at the first sublayer of the outermost layer. The high blockage of Na(+) ions is attributed to the high surface zeta potential of the first layer. The second layer, which is composed of macroporous structures, also facilitates Na(+) ion filtration. This study provides insights into the mechanism underlying water filtration through halophyte roots and serves as a basis for the development of a novel bio-inspired desalination method.

An Experimental Study on the Effect of Using Fresnel Lenses on the Performance of Solar Stills

NASA Astrophysics Data System (ADS)

Abdelsalam, Tarek I.; Abdel-Mesih, Bahy

The global water concern is mainly about the scarcity of fresh water resources despite the abundance of saline and brackish water in oceans, seas, and underground. Solar desalination offers a worthy solution to produce fresh water by using solar radiation, which also lessens the energy concern by offering a renewable source of energy to alter the consumption of fossil fuels and other non-renewable resources. One of the solar desalination technologies is the solar still system, which is a portable unit capable of producing distilled water by evaporating brackish or saline water by using solar thermal energy. The steam is then condensed on the inside of the glass cover and collected as fresh water. Solar stills are easy to manufacture and install using local materials and workmanship, which suits underprivileged remote communities that face difficulties in finding clean potable water, while locating near a source of saline water. However, efficiency and productivity of solar stills are still feeble when compared to other traditional desalination techniques. As an attempt to overcome these issues, an upgraded system is proposed and tested experimentally to augment the incoming solar radiation falling on the top glass surface of the still by concentrating extra solar radiation to preheat the flowing feedwater to the solar still system. The results of the experimental study showed that the integration of linear Fresnel lenses has approximately tripled the productivity of distilled water and improved efficiency of a solar still, by about 68.76 %, when compared to a conventional non-concentrating solar still.

A bubble column evaporator with basic flat-plate condenser for brackish and seawater desalination.

PubMed

Schmack, Mario; Ho, Goen; Anda, Martin

2016-01-01

This paper describes the development and experimental evaluation of a novel bubble column-based humidification-dehumidification system, for small-scale desalination of saline groundwater or seawater in remote regions. A bubble evaporator prototype was built and matched with a simple flat-plate type condenser for concept assessment. Consistent bubble evaporation rates of between 80 and 88 ml per hour were demonstrated. Particular focus was on the performance of the simple condenser prototype, manufactured from rectangular polyvinylchlorid plastic pipe and copper sheet, a material with a high thermal conductivity that quickly allows for conduction of the heat energy. Under laboratory conditions, a long narrow condenser model of 1500 mm length and 100 mm width achieved condensate recovery rates of around 73%, without the need for external cooling. The condenser prototype was assessed under a range of different physical conditions, that is, external water cooling, partial insulation and aspects of air circulation, via implementing an internal honeycomb screen structure. Estimated by extrapolation, an up-scaled bubble desalination system with a 1 m2 condenser may produce around 19 l of distilled water per day. Sodium chloride salt removal was found to be highly effective with condensate salt concentrations between 70 and 135 µS. Based on findings and with the intent to reduce material cost of the system, a shorter condenser length of 750 mm for the non-cooled (passive) condenser and of 500 mm for the water-cooled condenser was considered to be equally efficient as the experimentally evaluated prototype of 1500 mm length.

Deionization and desalination using electrostatic ion pumping

DOEpatents

Bourcier, William L.; Aines, Roger D.; Haslam, Jeffery J.; Schaldach, Charlene M.; O& #x27; Brien, Kevin C.; Cussler, Edward

2013-06-11

The present invention provides a new method and apparatus/system for purifying ionic solutions, such as, for example, desalinating water, using engineered charged surfaces to sorb ions from such solutions. Surface charge is applied externally, and is synchronized with oscillatory fluid movements between substantially parallel charged plates. Ions are held in place during fluid movement in one direction (because they are held in the electrical double layer), and released for transport during fluid movement in the opposite direction by removing the applied electric field. In this way the ions, such as salt, are "ratcheted" across the charged surface from the feed side to the concentrate side. The process itself is very simple and involves only pumps, charged surfaces, and manifolds for fluid collection.

Deionization and desalination using electrostatic ion pumping

DOEpatents

Bourcier, William L [Livermore, CA; Aines, Roger D [Livermore, CA; Haslam, Jeffery J [Livermore, CA; Schaldach, Charlene M [Pleasanton, CA; O'Brien, Kevin C [San Ramon, CA; Cussler, Edward [Edina, MN

2011-07-19

The present invention provides a new method and apparatus/system for purifying ionic solutions, such as, for example, desalinating water, using engineered charged surfaces to sorb ions from such solutions. Surface charge is applied externally, and is synchronized with oscillatory fluid movements between substantially parallel charged plates. Ions are held in place during fluid movement in one direction (because they are held in the electrical double layer), and released for transport during fluid movement in the opposite direction by removing the applied electric field. In this way the ions, such as salt, are "ratcheted" across the charged surface from the feed side to the concentrate side. The process itself is very simple and involves only pumps, charged surfaces, and manifolds for fluid collection.

New developments in flash radiography

NASA Astrophysics Data System (ADS)

Mattsson, Arne

2007-01-01

The paper will review some of the latest developments in flash radiography. A series of multi anode tubes has been developed. These are tubes with several x-ray sources within the same vacuum enclosure. The x-ray sources are closely spaced, to come as close as possible to a single source. The x-ray sources are sequentially pulsed, at times that can be independently chosen. Tubes for voltages in the range 150 - 500 kV, with up to eight x-ray sources, will be described. Combining a multi anode tube with an intensified CCD camera, will make it possible to generate short "x-ray movies". A new flash x-ray control system has been developed. The system is operated from a PC or Laptop. All parameters of a multi channel flash x-ray system can be remotely set and monitored. The system will automatically store important operation parameters.

Energy minimization strategies and renewable energy utilization for desalination: a review.

PubMed

Subramani, Arun; Badruzzaman, Mohammad; Oppenheimer, Joan; Jacangelo, Joseph G

2011-02-01

Energy is a significant cost in the economics of desalinating waters, but water scarcity is driving the rapid expansion in global installed capacity of desalination facilities. Conventional fossil fuels have been utilized as their main energy source, but recent concerns over greenhouse gas (GHG) emissions have promoted global development and implementation of energy minimization strategies and cleaner energy supplies. In this paper, a comprehensive review of energy minimization strategies for membrane-based desalination processes and utilization of lower GHG emission renewable energy resources is presented. The review covers the utilization of energy efficient design, high efficiency pumping, energy recovery devices, advanced membrane materials (nanocomposite, nanotube, and biomimetic), innovative technologies (forward osmosis, ion concentration polarization, and capacitive deionization), and renewable energy resources (solar, wind, and geothermal). Utilization of energy efficient design combined with high efficiency pumping and energy recovery devices have proven effective in full-scale applications. Integration of advanced membrane materials and innovative technologies for desalination show promise but lack long-term operational data. Implementation of renewable energy resources depends upon geography-specific abundance, a feasible means of handling renewable energy power intermittency, and solving technological and economic scale-up and permitting issues. Copyright © 2011 Elsevier Ltd. All rights reserved.

Seawater desalination and serum magnesium concentrations in Israel.

PubMed

Koren, Gideon; Shlezinger, Meital; Katz, Rachel; Shalev, Varda; Amitai, Yona

2017-04-01

With increasing shortage of fresh water globally, more countries are consuming desalinated seawater (DSW). In Israel >50% of drinking water is now derived from DSW. Desalination removes magnesium, and hypomagnesaemia has been associated with increased cardiac morbidity and mortality. Presently the impact of consuming DSW on body magnesium status has not been established. We quantified changes in serum magnesium in a large population based study (n = 66,764), before and after desalination in regions consuming DSW and in regions where DSW has not been used. In the communities that switched to DSW in 2013, the mean serum magnesium was 2.065 ± 0.19 mg/dl before desalination and fell to 2.057 ± 0.19 mg/dl thereafter (p < 0.0001). In these communities 1.62% of subjects exhibited serum magnesium concentrations ≤1.6 mg/dl between 2010 and 2013. This proportion increased by 24% between 2010-2013 and 2015-2016 to 2.01% (p = 0.0019). In contrast, no such changes were recorded in the communities that did not consume DSW. Due to the emerging evidence of increased cardiac morbidity and mortality associated with hypomagnesaemia, it is vital to consider re-introduction of magnesium to DSW.

Complex admixtures of clathrate hydrates in a water desalination method

DOEpatents

Simmons, Blake A [San Francisco, CA; Bradshaw, Robert W [Livermore, CA; Dedrick, Daniel E [Berkeley, CA; Anderson, David W [Riverbank, CA

2009-07-14

Disclosed is a method that achieves water desalination by utilizing and optimizing clathrate hydrate phenomena. Clathrate hydrates are crystalline compounds of gas and water that desalinate water by excluding salt molecules during crystallization. Contacting a hydrate forming gaseous species with water will spontaneously form hydrates at specific temperatures and pressures through the extraction of water molecules from the bulk phase followed by crystallite nucleation. Subsequent dissociation of pure hydrates yields fresh water and, if operated correctly, allows the hydrate-forming gas to be efficiently recycled into the process stream.

Non-invasive online wavelength measurements at FLASH2 and present benchmark

PubMed Central

Braune, Markus; Buck, Jens; Kuhlmann, Marion; Grunewald, Sören; Düsterer, Stefan; Viefhaus, Jens; Tiedtke, Kai

2018-01-01

At FLASH2, the free-electron laser radiation wavelength is routinely measured by an online spectrometer based on photoionization of gas targets. Photoelectrons are detected with time-of-flight spectrometers and the wavelength is determined by means of well known binding energies of the target species. The wavelength measurement is non-invasive and transparent with respect to running user experiments due to the low gas pressure applied. Sophisticated controls for setting the OPIS operation parameters have been created and integrated into the distributed object-oriented control system at FLASH2. Raw and processed data can be stored on request in the FLASH data acquisition system for later correlation with data from user experiments or re-analysis. In this paper, the commissioning of the instrument at FLASH2 and the challenges of space charge effects on wavelength determination are reported. Furthermore, strategies for fast data reduction and online data processing are presented. PMID:29271744

The Evolution and Structure of Extreme Optical Lightning Flashes.

PubMed

Peterson, Michael; Rudlosky, Scott; Deierling, Wiebke

2017-12-27

This study documents the composition, morphology, and motion of extreme optical lightning flashes observed by the Lightning Imaging Sensor (LIS). The furthest separation of LIS events (groups) in any flash is 135 km (89 km), the flash with the largest footprint had an illuminated area of 10,604 km 2 , and the most dendritic flash has 234 visible branches. The longest-duration convective LIS flash lasted 28 s and is overgrouped and not physical. The longest-duration convective-to-stratiform propagating flash lasted 7.4 s, while the longest-duration entirely stratiform flash lasted 4.3 s. The longest series of nearly consecutive groups in time lasted 242 ms. The most radiant recorded LIS group (i.e., "superbolt") is 735 times more radiant than the average group. Factors that impact these optical measures of flash morphology and evolution are discussed. While it is apparent that LIS can record the horizontal development of the lightning channel in some cases, radiative transfer within the cloud limits the flash extent and level of detail measured from orbit. These analyses nonetheless suggest that lightning imagers such as LIS and Geostationary Lightning Mapper can complement ground-based lightning locating systems for studying physical lightning phenomena across large geospatial domains.

Report on in-situ studies of flash sintering of uranium dioxide

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

Raftery, Alicia Marie

Flash sintering is a novel type of field assisted sintering that uses an electric field and current to provide densification of materials on very short time scales. The potential for field assisted sintering techniques to be used in producing nuclear fuel is gaining recognition due to the potential economic benefits and improvements in material properties. The flash sintering behavior has so far been linked to applied and material parameters, but the underlying mechanisms active during flash sintering have yet to be identified. This report summarizes the efforts to investigate flash sintering of uranium dioxide using dilatometer studies at Los Alamosmore » National Laboratory and two separate sets of in-situ studies at Brookhaven National Laboratory’s NSLS-II XPD-1 beamline. The purpose of the dilatometer studies was to understand individual parameter (applied and material) effects on the flash behavior and the purpose of the in-situ studies was to better understand the mechanisms active during flash sintering. As far as applied parameters, it was found that stoichiometry, or oxygen-to-metal ratio, has a significant effect on the flash behavior (time to flash and speed of flash). Composite systems were found to have degraded sintering behavior relative to pure UO 2. The critical field studies are complete for UO 2.00 and will be analyzed against an existing model for comparison. The in-situ studies showed that the strength of the field and current are directly related to the sample temperature, with temperature-driven phase changes occurring at high values. The existence of an ‘incubation time’ has been questioned, due to a continuous change in lattice parameter values from the moment that the field is applied. Some results from the in-situ experiments, which should provide evidence regarding ion migration, are still being analyzed. Some preliminary conclusions can be made from these results with regard to using field assisted sintering to fabricate nuclear fuel. First, the pure UO 2-based system shows promising behavior with flash sintering, but composite systems are likely to show better sintering behavior with spark plasma sintering. Efforts to develop these methods should therefore be tailored towards the likelihood of success. Additionally, modeling is a rapidly developing aspect of current flash sintering research and should be used in parallel with experiments. Ultimately, ongoing flash sintering studies on various materials, like those summarized in this report, are rapidly contributing to the feasibility of controlling this method for use in the future.« less

A new case for promoting wastewater reuse in Saudi Arabia: bringing energy into the water equation.

PubMed

Kajenthira, Arani; Siddiqi, Afreen; Anadon, Laura Diaz

2012-07-15

Saudi Arabia is the third-largest per capita water user worldwide and has addressed the disparity between its renewable water resources and domestic demand primarily through desalination and the abstraction of non-renewable groundwater. This study evaluates the potential costs of this approach in the industrial and municipal sectors, exploring economic, energy, and environmental costs (including CO2 emissions and possible coastal impacts). Although the energy intensity of desalination is a global concern, it is particularly urgent to rethink water supply options in Saudi Arabia because the entirety of its natural gas production is consumed domestically, primarily in petrochemical and desalination plants. This burgeoning demand is necessitating the development of more expensive high-sulfur gas resources that could make desalination even pricier. The evolving necessity to conserve non-renewable water and energy resources and mitigate GHG emissions in the region also requires policy makers to weigh in much more considerably the energy and environmental costs of desalination. This paper suggests that in Saudi Arabia, the implementation of increased water conservation and reuse across the oil and natural gas sectors could conserve up to 29% of total industrial water withdrawals at costs recovered over 0-30 years, depending on the specific improvement. This work also indicates that increasing wastewater treatment and reuse in six high-altitude inland cities could save a further $225 million (2009 dollars) and conserve 2% of Saudi Arabia's annual electricity consumption. By these estimates, some anticipated investments in desalination projects could be deferred by improving water efficiency in industry and prioritizing investment in sewage and water distribution networks that would ensure more effective water reclamation and reuse. Simultaneously, such initiatives would conserve non-renewable natural gas resources and could help prevent the lock-in of potentially unnecessary desalination infrastructure that is likely to become more energy and cost efficient in future. Copyright © 2012 Elsevier Ltd. All rights reserved.

Capacitive deionization on-chip as a method for microfluidic sample preparation.

PubMed

Roelofs, Susan H; Kim, Bumjoo; Eijkel, Jan C T; Han, Jongyoon; van den Berg, Albert; Odijk, Mathieu

2015-03-21

Desalination as a sample preparation step is essential for noise reduction and reproducibility of mass spectrometry measurements. A specific example is the analysis of proteins for medical research and clinical applications. Salts and buffers that are present in samples need to be removed before analysis to improve the signal-to-noise ratio. Capacitive deionization is an electrostatic desalination (CDI) technique which uses two porous electrodes facing each other to remove ions from a solution. Upon the application of a potential of 0.5 V ions migrate to the electrodes and are stored in the electrical double layer. In this article we demonstrate CDI on a chip, and desalinate a solution by the removal of 23% of Na(+) and Cl(-) ions, while the concentration of a larger molecule (FITC-dextran) remains unchanged. For the first time impedance spectroscopy is introduced to monitor the salt concentration in situ in real-time in between the two desalination electrodes.

CFD Analysis of Evaporation-Condensation Phenomenon In an Evaporation Chamber of Natural Vacuum Solar Desalination

NASA Astrophysics Data System (ADS)

Ambarita, H.; Ronowikarto, A. D.; Siregar, R. E. T.; Setyawan, E. Y.

2018-01-01

Desalination technologies is one of solutions for water scarcity. With using renewable energy, like solar energy, wind energy, and geothermal energy, expected will reduce the energy demand. This required study on the modeling and transport parameters determination of natural vacuum solar desalination by using computational fluid dynamics (CFD) method to simulate the model. A three-dimensional case, two-phase model was developed for evaporation-condensation phenomenon in natural vacuum solar desalination. The CFD simulation results were compared with the avalaible experimental data. The simulation results shows inthat there is a phenomenon of evaporation-condensation in an evaporation chamber. From the simulation, the fresh water productivity is 2.21 litre, and from the experimental is 2.1 litre. This study shows there’s an error of magnitude 0.4%. The CFD results also show that, vacuum pressure will degrade the saturation temperature of sea water.

A Modern Apparatus for Performing Flash Chromatography: An Experiment for the Organic Laboratory

ERIC Educational Resources Information Center

Naumiec, Gregory R.; Del Padre, Angela N.; Hooper, Matthew M.; Germaine, Alison St.; DeBoef, Brenton

2013-01-01

A modern apparatus for performing flash chromatography using commercially available, prepacked silica cartridges has been developed. The key advantage of this system, when compared to traditional flash chromatography, is its use of commercially available silica cartridges, which obviates the need for students to handle silica gel. The apparatus…

BRAIN CHOLINESTERASE INHIBITION PRODUCED BY PROPOXUR AND DEPRESSION OF THE PHOTIC AFTER DISCHARGE OF FLASH EVOKED POTENTIALS IN LONG EVANS RATS.

EPA Science Inventory

Propoxur is a widely used N-methyl carbamate pesticide that acts by inhibiting cholinesterases (ChE), which may lead to cholinergic toxicity. Flash evoked potentials (FEPs) are a neurophysiological response following stimulation of the visual system with flashes of light. They ar...

Cost calculation for a flash glucose monitoring system for UK adults with type 1 diabetes mellitus receiving intensive insulin treatment.

PubMed

Hellmund, Richard; Weitgasser, Raimund; Blissett, Deirdre

2018-04-01

To estimate the costs associated with a flash glucose monitoring system as a replacement for routine self-monitoring of blood glucose (SMBG) in patients with type 1 diabetes mellitus (T1DM) using intensive insulin, from a UK National Health Service (NHS) perspective. The base-case cost calculation was created using the maximum frequency of glucose monitoring recommended by the 2015 National Institute for Health and Care Excellence guidelines (4-10 tests per day). Scenario analyses considered SMBG at the frequency observed in the IMPACT clinical trial (5.6 tests per day) and at the frequency of flash monitoring observed in a real-world analysis (16 tests per day). A further scenario included potential costs associated with severe hypoglycaemia. In the base case, the annual cost per patient using flash monitoring was £234 (19%) lower compared with routine SMBG (10 tests per day). In scenario analyses, the annual cost per patient of flash monitoring compared with 5.6 and 16 SMBG tests per day was £296 higher and £957 lower, respectively. The annual cost of severe hypoglycaemia for flash monitoring users was estimated to be £221 per patient, compared with £428 for routine SMBG users (based on 5.6 tests/day), corresponding to a reduction in costs of £207. The flash monitoring system has a modest impact on glucose monitoring costs for the UK NHS for patients with T1DM using intensive insulin. For people requiring frequent tests, flash monitoring may be cost saving, especially when taking into account potential reductions in the rate of severe hypoglycaemia. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

FPGA Flash Memory High Speed Data Acquisition

NASA Technical Reports Server (NTRS)

Gonzalez, April

2013-01-01

The purpose of this research is to design and implement a VHDL ONFI Controller module for a Modular Instrumentation System. The goal of the Modular Instrumentation System will be to have a low power device that will store data and send the data at a low speed to a processor. The benefit of such a system will give an advantage over other purchased binary IP due to the capability of allowing NASA to re-use and modify the memory controller module. To accomplish the performance criteria of a low power system, an in house auxiliary board (Flash/ADC board), FPGA development kit, debug board, and modular instrumentation board will be jointly used for the data acquisition. The Flash/ADC board contains four, 1 MSPS, input channel signals and an Open NAND Flash memory module with an analog to digital converter. The ADC, data bits, and control line signals from the board are sent to an Microsemi/Actel FPGA development kit for VHDL programming of the flash memory WRITE, READ, READ STATUS, ERASE, and RESET operation waveforms using Libero software. The debug board will be used for verification of the analog input signal and be able to communicate via serial interface with the module instrumentation. The scope of the new controller module was to find and develop an ONFI controller with the debug board layout designed and completed for manufacture. Successful flash memory operation waveform test routines were completed, simulated, and tested to work on the FPGA board. Through connection of the Flash/ADC board with the FPGA, it was found that the device specifications were not being meet with Vdd reaching half of its voltage. Further testing showed that it was the manufactured Flash/ADC board that contained a misalignment with the ONFI memory module traces. The errors proved to be too great to fix in the time limit set for the project.

Efficiency mark of the two-product power complex of nuclear power plant

NASA Astrophysics Data System (ADS)

Khrustalev, V. A.; Suchkov, V. M.

2017-11-01

The article discusses the combining nuclear power plants (NPP) with pressurized water reactors and distillation-desalination plants (DDP), their joint mode of operation during periods of coating failures of the electric power load graphs and thermo-economical efficiency. Along with the release of heat and generation of electric energy a desalination complex with the nuclear power plant produces distillate. Part of the selected steam “irretrievably lost” with a mix of condensation of this vapor in a desalination machine with a flow of water for distillation. It means that this steam transforms into condition of acquired product - distillate. The article presents technical solutions for the return of the working fluid for turbine К-1000-60/1500-2 и К-1200-6,8/50, as well as permissible part of low pressure regime according to the number of desalination units for each turbine. Patent for the proposed two-product energy complex, obtained by Gagarin State Technical University is analyzed. The energy complex has such system advantages as increasing the capacity factor of a nuclear reactor and also allows to solve the problem of shortage of fresh water. Thermo-economics effectiveness of this complex is determined by introducing a factor-“thermo-economic index”. During analyzing of the results of the calculations of a thermo-economic index we can see a strong influence of the cost factor of the distillate on the market. Then higher participation of the desalination plant in coverage of the failures of the graphs of the electric loading then smaller the payback period of the NPP. It is manifested more clearly, as it’s shown in the article, when pricing options depend on time of day and the configuration of the daily electric load diagram. In the geographical locations of the NPPs with PWR the Russian performance in a number of regions with low freshwater resources and weak internal electrical connections combined with DDP might be one of the ways to improve the competitiveness of NPPs, especially for foreign coastal areas.

Harmful algae and their potential impacts on desalination operations off southern California.

PubMed

Caron, David A; Garneau, Marie-Eve; Seubert, Erica; Howard, Meredith D A; Darjany, Lindsay; Schnetzer, Astrid; Cetinić, Ivona; Filteau, Gerry; Lauri, Phil; Jones, Burton; Trussell, Shane

2010-01-01

Seawater desalination by reverse osmosis (RO) is a reliable method for augmenting drinking water supplies. In recent years, the number and size of these water projects have increased dramatically. As freshwater resources become limited due to global climate change, rising demand, and exhausted local water supplies, seawater desalination will play an important role in the world's future water supply, reaching far beyond its deep roots in the Middle East. Emerging contaminants have been widely discussed with respect to wastewater and freshwater sources, but also must be considered for seawater desalination facilities to ensure the long-term safety and suitability of this emerging water supply. Harmful algal blooms, frequently referred to as 'red tides' due to their vibrant colors, are a concern for desalination plants due to the high biomass of microalgae present in ocean waters during these events, and a variety of substances that some of these algae produce. These compounds range from noxious substances to powerful neurotoxins that constitute significant public health risks if they are not effectively and completely removed by the RO membranes. Algal blooms can cause significant operational issues that result in increased chemical consumption, increased membrane fouling rates, and in extreme cases, a plant to be taken off-line. Early algal bloom detection by desalination facilities is essential so that operational adjustments can be made to ensure that production capacity remains unaffected. This review identifies the toxic substances, their known producers, and our present state of knowledge regarding the causes of toxic episodes, with a special focus on the Southern California Bight. (c) 2009 Elsevier Ltd. All rights reserved.

The techno-economic optimization of a 100MWe CSP-desalination plant in Arandis, Namibia

NASA Astrophysics Data System (ADS)

Dall, Ernest P.; Hoffmann, Jaap E.

2017-06-01

Energy is a key factor responsible for a country's economic growth and prosperity. It is closely related to the main global challenges namely: poverty mitigation, global environmental change and food and water security [1.]. Concentrating solar power (CSP) is steadily gaining more market acceptance as the cost of electricity from CSP power plants progressively declines. The cogeneration of electricity and water is an attractive prospect for future CSP developments as the simultaneous production of power and potable water can have positive economic implications towards increasing the feasibility of CSP plant developments [2.]. The highest concentrations of direct normal irradiation are located relatively close to Western coastal and Middle-Eastern North-African regions. It is for this reason worthwhile investigating the possibility of CSP-desalination (CSP+D) plants as a future sustainable method for providing both electricity and water with significantly reduced carbon emissions and potential cost reductions. This study investigates the techno-economic feasibility of integrating a low-temperature thermal desalination plant to serve as the condenser as opposed to a conventional dry-cooled CSP plant in Arandis, Namibia. It outlines the possible benefits of the integration CSP+D in terms of overall cost of water and electricity. The high capital costs of thermal desalination heat exchangers as well as the pumping of seawater far inland is the most significant barrier in making this approach competitive against more conventional desalination methods such as reverse osmosis. The compromise between the lowest levelized cost of electricity and water depends on the sizing and the top brine temperature of the desalination plant.

Development of a Desalination Membrane Bioinspired by Mangrove Roots for Spontaneous Filtration of Sodium Ions.

PubMed

Kim, Kiwoong; Kim, Hyejeong; Lim, Jae Hong; Lee, Sang Joon

2016-12-27

The shortage of available fresh water is one of the global issues presently faced by humanity. To determine a solution to this problem, the survival strategies of plants have been examined. In this study, a nature-inspired membrane with a highly charged surface is proposed as an effective membrane for the filtration of saline water. To mimic the desalination characteristics of mangrove roots, a macroporous membrane based on polyethylene terephthalate is treated with polyelectrolytes using a layer-by-layer deposition method. The fabricated membrane surface has a highly negative charged ζ-potential value of -97.5 ± 4.3 mV, similar to that of the first layer of mangrove roots. Desalination of saline water using this membrane shows a high salt retention rate of 96.5%. The highly charged surface of the membrane may induce a relatively thick and stable ion depletion zone in front of the membrane. As a result, most co-ions are repelled from the membrane surface, and counterions are also rejected by virtue of their electroneutrality. The water permeability is found to be 7.60-7.69 L/m 2 ·h, which is 10 times higher than that of the reverse osmosis desalination method. This nature-inspired filtration membrane exhibits steady desalination performance over 72 h of operation, successfully demonstrating the stable filtration of saline water. This nature-inspired membrane is applicable to the design of a small-scale, portable, and energy-free desalination device for use in third-world countries or small villages.

Direct evidence for a position input to the smooth pursuit system.

PubMed

Blohm, Gunnar; Missal, Marcus; Lefèvre, Philippe

2005-07-01

When objects move in our environment, the orientation of the visual axis in space requires the coordination of two types of eye movements: saccades and smooth pursuit. The principal input to the saccadic system is position error, whereas it is velocity error for the smooth pursuit system. Recently, it has been shown that catch-up saccades to moving targets are triggered and programmed by using velocity error in addition to position error. Here, we show that, when a visual target is flashed during ongoing smooth pursuit, it evokes a smooth eye movement toward the flash. The velocity of this evoked smooth movement is proportional to the position error of the flash; it is neither influenced by the velocity of the ongoing smooth pursuit eye movement nor by the occurrence of a saccade, but the effect is absent if the flash is ignored by the subject. Furthermore, the response started around 85 ms after the flash presentation and decayed with an average time constant of 276 ms. Thus this is the first direct evidence of a position input to the smooth pursuit system. This study shows further evidence for a coupling between saccadic and smooth pursuit systems. It also suggests that there is an interaction between position and velocity error signals in the control of more complex movements.

Hydro, wind and solar power as a base for a 100% renewable energy supply for South and Central America.

PubMed

Barbosa, Larissa de Souza Noel Simas; Bogdanov, Dmitrii; Vainikka, Pasi; Breyer, Christian

2017-01-01

Power systems for South and Central America based on 100% renewable energy (RE) in the year 2030 were calculated for the first time using an hourly resolved energy model. The region was subdivided into 15 sub-regions. Four different scenarios were considered: three according to different high voltage direct current (HVDC) transmission grid development levels (region, country, area-wide) and one integrated scenario that considers water desalination and industrial gas demand supplied by synthetic natural gas via power-to-gas (PtG). RE is not only able to cover 1813 TWh of estimated electricity demand of the area in 2030 but also able to generate the electricity needed to fulfil 3.9 billion m3 of water desalination and 640 TWhLHV of synthetic natural gas demand. Existing hydro dams can be used as virtual batteries for solar and wind electricity storage, diminishing the role of storage technologies. The results for total levelized cost of electricity (LCOE) are decreased from 62 €/MWh for a highly decentralized to 56 €/MWh for a highly centralized grid scenario (currency value of the year 2015). For the integrated scenario, the levelized cost of gas (LCOG) and the levelized cost of water (LCOW) are 95 €/MWhLHV and 0.91 €/m3, respectively. A reduction of 8% in total cost and 5% in electricity generation was achieved when integrating desalination and power-to-gas into the system.

Hydro, wind and solar power as a base for a 100% renewable energy supply for South and Central America

PubMed Central

Barbosa, Larissa de Souza Noel Simas; Bogdanov, Dmitrii; Vainikka, Pasi; Breyer, Christian

2017-01-01

Power systems for South and Central America based on 100% renewable energy (RE) in the year 2030 were calculated for the first time using an hourly resolved energy model. The region was subdivided into 15 sub-regions. Four different scenarios were considered: three according to different high voltage direct current (HVDC) transmission grid development levels (region, country, area-wide) and one integrated scenario that considers water desalination and industrial gas demand supplied by synthetic natural gas via power-to-gas (PtG). RE is not only able to cover 1813 TWh of estimated electricity demand of the area in 2030 but also able to generate the electricity needed to fulfil 3.9 billion m3 of water desalination and 640 TWhLHV of synthetic natural gas demand. Existing hydro dams can be used as virtual batteries for solar and wind electricity storage, diminishing the role of storage technologies. The results for total levelized cost of electricity (LCOE) are decreased from 62 €/MWh for a highly decentralized to 56 €/MWh for a highly centralized grid scenario (currency value of the year 2015). For the integrated scenario, the levelized cost of gas (LCOG) and the levelized cost of water (LCOW) are 95 €/MWhLHV and 0.91 €/m3, respectively. A reduction of 8% in total cost and 5% in electricity generation was achieved when integrating desalination and power-to-gas into the system. PMID:28329023

GOES-16 Geostationary Lightning Mapper Comparison with the Earth Networks Total Lightning Network

NASA Astrophysics Data System (ADS)

Lapierre, J. L.; Stock, M.; Zhu, Y.

2017-12-01

Lightning location systems have shown to be an integral part of weather research and forecasting. The launch of the GOES-16 Geostationary Lightning Mapper (GLM) will provide a new tool to help improve lightning detection throughout the Americas and ocean regions. However, before this data can be effectively used, there must be a thorough analysis of its performance to validate the data it produces. Here, we compare GLM data to data from the Earth Networks Total Lightning Network (ENTLN). We analyze data during the months of May and June of 2017 to determine the detection efficiency of each system. A successful match occurs when two flashes overlap in time and are less than 0.2 degrees apart. Of the flashes detected by ENTLN, GLM detects about 50% overall. The highest DEs for GLM are over the ocean and South America, and lowest are in Central America and the Northeastern and Western parts of the U.S. Of the flashes detected by GLM, ENTLN detected over 80% in the Central and Eastern parts of the U.S. and 10-20% in Central and South America. Finally, we determined all the unique flashes detected by both systems and determined the DE of both systems from this unique flash dataset. We find that GLM does very well in South America, over the tropical islands in the Caribbean Sea as well as Northern U.S. It detects above 50% of the unique flashes over Central and off the Eastern Coast of the U.S. as well as in Mexico. GLM detects less than 50% of the unique flashes over Florida, the Mid-Atlantic, Mid-West, and Southwestern U.S., areas where ENTLN is expected to perform well.

Analysis of a Wave-Powered, Reverse-Osmosis System and its Economic Availability in the United States

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

Yu, Yi-Hsiang; Jenne, Dale S

A wave energy converter (WEC) system has the potential to convert the wave energy resource directly into the high-pressure flow that is needed by the desalination system to permeate saltwater through the reverse-osmosis membrane to generate clean water. In this study, a wave-to-water numerical model was developed to investigate the potential use of a wave-powered desalination system (WPDS) for water production in the United States. The model was developed by coupling a time-domain radiation-and-diffraction-method-based numerical tool (WEC-Sim) for predicting the hydrodynamic performance of WECs with a solution-diffusion model that was used to simulate the reverse-osmosis process. To evaluate the feasibilitymore » of the WPDS, the wave-to-water numerical model was applied to simulate a desalination system that used an oscillating surge WEC device to pump seawater through the system. The annual water production was estimated based on the wave resource at a reference site on the coast of northern California to investigate the potential cost of water in that area, where the cost of water and electricity is high compared to other regions. In the scenario evaluated, for a 100-unit utility-scale array, the estimated levelized cost of energy for these WECs is about 3-6 times the U.S.'s current, unsubsidized electricity rates. However, with clean water as an end product and by directly producing pressurized water with WECs, rather than electricity as an intermediary, it is presently only 12% greater than typical water cost in California. This study suggests that a WEC array that produces water may be a viable, near-term solution to the nation's water supply, and the niche application of the WPDS may also provide developers with new opportunities to further develop technologies that benefit both the electric and drinking water markets.« less

Analysis of a Wave-Powered, Reverse-Osmosis System and Its Economic Availability in the United States: Preprint

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

Yu, Yi-Hsiang; Jenne, Dale S

A wave energy converter (WEC) system has the potential to convert the wave energy resource directly into the high-pressure flow that is needed by the desalination system to permeate saltwater through the reverse-osmosis membrane to generate clean water. In this study, a wave-to-water numerical model was developed to investigate the potential use of a wave-powered desalination system (WPDS) for water production in the United States. The model was developed by coupling a time-domain radiation-and-diffraction-method-based numerical tool (WEC-Sim) for predicting the hydrodynamic performance of WECs with a solution-diffusion model that was used to simulate the reverse-osmosis process. To evaluate the feasibilitymore » of the WPDS, the wave-to-water numerical model was applied to simulate a desalination system that used an oscillating surge WEC device to pump seawater through the system. The annual water production was estimated based on the wave resource at a reference site on the coast of northern California to investigate the potential cost of water in that area, where the cost of water and electricity is high compared to other regions. In the scenario evaluated, for a 100-unit utility-scale electricity-producing array, the estimated levelized cost of energy for these WECs is about 3-6 times the U.S.'s current, unsubsidized electricity rates. However, with clean water as an end product and by directly producing pressurized water with WECs, rather than electricity as an intermediary, it is presently only 12 percent greater than typical water cost in California. This study suggests that a WEC array that produces water may be a viable, near-term solution to the nation's water supply, and the niche application of the WPDS may also provide developers with new opportunities to further develop technologies that benefit both the electric and drinking water markets.« less

Evaluation of 1.5-T Cell Flash Memory Total Ionizing Dose Response

NASA Astrophysics Data System (ADS)

Clark, Lawrence T.; Holbert, Keith E.; Adams, James W.; Navale, Harshad; Anderson, Blake C.

2015-12-01

Flash memory is an essential part of systems used in harsh environments, experienced by both terrestrial and aerospace TID applications. This paper presents studies of COTS flash memory TID hardness. While there is substantial literature on flash memory TID response, this work focuses for the first time on 1.5 transistor per cell flash memory. The experimental results show hardness varying from about 100 krad(Si) to over 250 krad(Si) depending on the usage model. We explore the circuit and device aspects of the results, based on the extensive reliability literature for this flash memory type. Failure modes indicate both device damage and circuit marginalities. Sector erase failure limits, but read only operation allows TID exceeding 200 krad(Si). The failures are analyzed by type.

Detoxification and protein quality control markers in the mussel Mytilus edulis (Linnaeus) exposed to crude oil: Salinity-induced modulation

NASA Astrophysics Data System (ADS)

Lysenko, Liudmila; Sukhovskaya, Irina; Borvinskaya, Ekaterina; Krupnova, Marina; Kantserova, Nadezda; Bakhmet, Igor'; Nemova, Nina

2015-12-01

Marine and coastal ecosystems are influenced by oil from chronic contamination or sporadic oil spills. An oil spill was simulated in an aquarium-based experiment designed to reproduce interactions of crude oil with inert environmental components, particularly adhesion on shore gravel and dissolution in sea water. Total experimental oil concentrations were in the range of comparable hydrocarbon concentrations following an oil spill. Furthermore, the possible interaction of a chemical (anthropogenic) stressor, such as oil PAHs, and a "natural" stressor like desalination, was simulated. In order to assess the biological effects of crude oil contamination and desalination (each individually and in combination) on the blue mussel Mytilus edulis L., biochemical responses were estimated including: detoxification capacity by glutathione-S-transferase (GST) activity, reduced glutathione (GSH) level, and protein quality control by autophagy-related proteases cathepsin B (CatB), cathepsin D (CatD), and calcium-dependent calpain-like proteases. Oil treatment stimulated defense system response in the mussels with primary effects on GST and protease-mediated reactions such as the activation of CatB, CatD, and calpains. Most of biomarkers responded to oil in a dose- and time-dependent manner. Additional environmental stress, such as desalination, promoted the oil-induced activation of GST and CatD while resulting in a delay or impairement of the defense response to oil by GSH and proteases CatB and calpains. Thus, biomarker data shows that combined effects of oil compounds and desalination can be realized in both a synergistic and an antagonistic manner. The evaluated interaction between oil pollution effects and sub-optimal salinity on M. edulis indicates the potential risk of maladaptation to the biota of estuaries.

Life-cycle energy impacts for adapting an urban water supply system to droughts.

PubMed

Lam, Ka Leung; Stokes-Draut, Jennifer R; Horvath, Arpad; Lane, Joe L; Kenway, Steven J; Lant, Paul A

2017-12-15

In recent years, cities in some water stressed regions have explored alternative water sources such as seawater desalination and potable water recycling in spite of concerns over increasing energy consumption. In this study, we evaluate the current and future life-cycle energy impacts of four alternative water supply strategies introduced during a decade-long drought in South East Queensland (SEQ), Australia. These strategies were: seawater desalination, indirect potable water recycling, network integration, and rainwater tanks. Our work highlights the energy burden of alternative water supply strategies which added approximately 24% life-cycle energy use to the existing supply system (with surface water sources) in SEQ even for a current post-drought low utilisation status. Over half of this additional life-cycle energy use was from the centralised alternative supply strategies. Rainwater tanks contributed an estimated 3% to regional water supply, but added over 10% life-cycle energy use to the existing system. In the future scenario analysis, we compare the life-cycle energy use between "Normal", "Dry", "High water demand" and "Design capacity" scenarios. In the "Normal" scenario, a long-term low utilisation of the desalination system and the water recycling system has greatly reduced the energy burden of these centralised strategies to only 13%. In contrast, higher utilisation in the unlikely "Dry" and "Design capacity" scenarios add 86% and 140% to life-cycle energy use of the existing system respectively. In the "High water demand" scenario, a 20% increase in per capita water use over 20 years "consumes" more energy than is used by the four alternative strategies in the "Normal" scenario. This research provides insight for developing more realistic long-term scenarios to evaluate and compare life-cycle energy impacts of drought-adaptation infrastructure and regional decentralised water sources. Scenario building for life-cycle assessments of water supply systems should consider i) climate variability and, therefore, infrastructure utilisation rate, ii) potential under-utilisation for both installed centralised and decentralised sources, and iii) the potential energy penalty for operating infrastructure well below its design capacity (e.g., the operational energy intensity of the desalination system is three times higher at low utilisation rates). This study illustrates that evaluating the life-cycle energy use and intensity of these type of supply sources without considering their realistic long-term operating scenario(s) can potentially distort and overemphasise their energy implications. To other water stressed regions, this work shows that managing long-term water demand is also important, in addition to acknowledging the energy-intensive nature of some alternative water sources. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phase transformation in the alumina-titania system during flash sintering experiments

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

Jha, S. K.; Lebrun, J. M.; Raj, R.

2016-02-01

We show that phase transformation in the alumina–titania system, which produces aluminum-titanate, follows an unusual trajectory during flash sintering. The experiments begin with mixed powders of alumina–titania and end in dense microstructures that are transformed into aluminum-titanate. The sintering and the phase transformation are separated in time, with the sintering occurs during Stage II, and phase transformation during Stage III of the flash sintering experiment. Stage III is the steady-state condition of flash activated state that is established under current control, while Stage II is the period of transition from voltage to current control. The extent of phase transformation increasesmore » with the current density and the hold time in Stage III.« less

Asymmetric programming: a highly reliable metadata allocation strategy for MLC NAND flash memory-based sensor systems.

PubMed

Huang, Min; Liu, Zhaoqing; Qiao, Liyan

2014-10-10

While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it's critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB) pages which are more reliable than least significant bit (LSB) pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme.

Asymmetric Programming: A Highly Reliable Metadata Allocation Strategy for MLC NAND Flash Memory-Based Sensor Systems

PubMed Central

Huang, Min; Liu, Zhaoqing; Qiao, Liyan

2014-01-01

While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it's critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB) pages which are more reliable than least significant bit (LSB) pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme. PMID:25310473

Exploiting interfacial water properties for desalination and purification applications.

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

Xu, Hongwu; Varma, Sameer; Nyman, May Devan

2008-09-01

A molecular-scale interpretation of interfacial processes is often downplayed in the analysis of traditional water treatment methods. However, such an approach is critical for the development of enhanced performance in traditional desalination and water treatments. Water confined between surfaces, within channels, or in pores is ubiquitous in technology and nature. Its physical and chemical properties in such environments are unpredictably different from bulk water. As a result, advances in water desalination and purification methods may be accomplished through an improved analysis of water behavior in these challenging environments using state-of-the-art microscopy, spectroscopy, experimental, and computational methods.

Mesoporous Three-Dimensional Graphene Networks for Highly Efficient Solar Desalination under 1 sun Illumination.

PubMed

Kim, Kwanghyun; Yu, Sunyoung; An, Cheolwon; Kim, Sung-Wook; Jang, Ji-Hyun

2018-05-09

Solar desalination via thermal evaporation of seawater is one of the most promising technologies for addressing the serious problem of global water scarcity because it does not require additional supporting energy other than infinite solar energy for generating clean water. However, low efficiency and a large amount of heat loss are considered critical limitations of solar desalination technology. The combination of mesoporous three-dimensional graphene networks (3DGNs) with a high solar absorption property and water-transporting wood pieces with a thermal insulation property has exhibited greatly enhanced solar-to-vapor conversion efficiency. 3DGN deposited on a wood piece provides an outstanding value of solar-to-vapor conversion efficiency, about 91.8%, under 1 sun illumination and excellent desalination efficiency of 5 orders salinity decrement. The mass-producible 3DGN enriched with many mesopores efficiently releases the vapors from an enormous area of the surface by heat localization on the top surface of the wood piece. Because the efficient solar desalination device made by 3DGN on the wood piece is highly scalable and inexpensive, it could serve as one of the main sources for the worldwide supply of purified water achieved via earth-abundant materials without an extra supporting energy source.

Removal of Radionuclides from Waste Water at Fukushima Daiichi Nuclear Power Plant: Desalination and Adsorption Methods - 13126

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

Kani, Yuko; Kamosida, Mamoru; Watanabe, Daisuke

Waste water containing high levels of radionuclides due to the Fukushima Daiichi Nuclear Power Plant accident, has been treated by the adsorption removal and reverse-osmosis (RO) desalination to allow water re-use for cooling the reactors. Radionuclides in the waste water are collected in the adsorbent medium and the RO concentrate (RO brine) in the water treatment system currently operated at the Fukushima Daiichi site. In this paper, we have studied the behavior of radionuclides in the presently applied RO desalination system and the removal of radionuclides in possible additional adsorption systems for the Fukushima Daiichi waste water treatment. Regarding themore » RO desalination system, decontamination factors (DFs) of the elements present in the waste water were obtained by lab-scale testing using an RO unit and simulated waste water with non-radioactive elements. The results of the lab-scale testing using representative elements showed that the DF for each element depended on its hydrated ionic radius: the larger the hydrated ionic radius of the element, the higher its DF is. Thus, the DF of each element in the waste water could be estimated based on its hydrated ionic radius. For the adsorption system to remove radionuclides more effectively, we studied adsorption behavior of typical elements, such as radioactive cesium and strontium, by various kinds of adsorbents using batch and column testing. We used batch testing to measure distribution coefficients (K{sub d}s) for cesium and strontium onto adsorbents under different brine concentrations that simulated waste water conditions at the Fukushima Daiichi site. For cesium adsorbents, K{sub d}s with different dependency on the brine concentration were observed based on the mechanism of cesium adsorption. As for strontium, K{sub d}s decreased as the brine concentration increased for any adsorbents which adsorbed strontium by intercalation and by ion exchange. The adsorbent titanium oxide had higher K{sub d}s and it was used for the column testing to obtain breakthrough curves under various conditions of pH and brine concentration. The breakthrough point had a dependency on pH and the brine concentration. We found that when the pH was higher or the brine concentration was lower, the longer it took to reach the breakthrough point. The inhibition of strontium adsorption by alkali earth metals would be diminished for conditions of higher pH and lower brine concentration. (authors)« less

The Evolution and Structure of Extreme Optical Lightning Flashes

PubMed Central

Peterson, Michael; Rudlosky, Scott; Deierling, Wiebke

2018-01-01

This study documents the composition, morphology, and motion of extreme optical lightning flashes observed by the Lightning Imaging Sensor (LIS). The furthest separation of LIS events (groups) in any flash is 135 km (89 km), the flash with the largest footprint had an illuminated area of 10,604 km2, and the most dendritic flash has 234 visible branches. The longest-duration convective LIS flash lasted 28 s and is overgrouped and not physical. The longest-duration convective-to-stratiform propagating flash lasted 7.4 s, while the longest-duration entirely stratiform flash lasted 4.3 s. The longest series of nearly consecutive groups in time lasted 242 ms. The most radiant recorded LIS group (i.e., “superbolt”) is 735 times more radiant than the average group. Factors that impact these optical measures of flash morphology and evolution are discussed. While it is apparent that LIS can record the horizontal development of the lightning channel in some cases, radiative transfer within the cloud limits the flash extent and level of detail measured from orbit. These analyses nonetheless suggest that lightning imagers such as LIS and Geostationary Lightning Mapper can complement ground-based lightning locating systems for studying physical lightning phenomena across large geospatial domains. PMID:29527425

Timing in a FLASH

NASA Astrophysics Data System (ADS)

Hoek, M.; Cardinali, M.; Corell, O.; Dickescheid, M.; Ferretti B., M. I.; Lauth, W.; Schlimme, B. S.; Sfienti, C.; Thiel, M.

2017-12-01

A prototype detector, called FLASH (Fast Light Acquiring Start Hodoscope), was built to provide precise Time-of-Flight (TOF) measurements and reference timestamps for detector setups at external beam lines. Radiator bars, made of synthetic fused silica, were coupled to a fast MCP-PMT with 64 channels and read out with custom electronics using Time-over-Threshold (TOT) for signal characterization. The TRB3 system, a high-precision TDC implemented in an FPGA, was used as data acquisition system. The performance of a system consisting of two FLASH units was investigated at a dedicated test experiment at the Mainz Microtron (MAMI) accelerator using its 855 MeV electron beam. The TOT measurement enabled time walk corrections and an overall TOF resolution of ∼70 ps could be achieved which translates into a resolution of ∼50 ps per FLASH unit. The intrinsic resolution of the frontend electronics including the TDC was measured to be less than 25 ps.

An Implicit Solver on A Parallel Block-Structured Adaptive Mesh Grid for FLASH

NASA Astrophysics Data System (ADS)

Lee, D.; Gopal, S.; Mohapatra, P.

2012-07-01

We introduce a fully implicit solver for FLASH based on a Jacobian-Free Newton-Krylov (JFNK) approach with an appropriate preconditioner. The main goal of developing this JFNK-type implicit solver is to provide efficient high-order numerical algorithms and methodology for simulating stiff systems of differential equations on large-scale parallel computer architectures. A large number of natural problems in nonlinear physics involve a wide range of spatial and time scales of interest. A system that encompasses such a wide magnitude of scales is described as "stiff." A stiff system can arise in many different fields of physics, including fluid dynamics/aerodynamics, laboratory/space plasma physics, low Mach number flows, reactive flows, radiation hydrodynamics, and geophysical flows. One of the big challenges in solving such a stiff system using current-day computational resources lies in resolving time and length scales varying by several orders of magnitude. We introduce FLASH's preliminary implementation of a time-accurate JFNK-based implicit solver in the framework of FLASH's unsplit hydro solver.

340nm UV LED excitation in time-resolved fluorescence system for europium-based immunoassays detection

NASA Astrophysics Data System (ADS)

Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter; Pedersen, Christian

2017-02-01

In immunoassay analyzers for in-vitro diagnostics, Xenon flash lamps have been widely used as excitation light sources. Recent advancements in UV LED technology and its advantages over the flash lamps such as smaller footprint, better wall-plug efficiency, narrow emission spectrum, and no significant afterglow, have made them attractive light sources for gated detection systems. In this paper, we report on the implementation of a 340 nm UV LED based time-resolved fluorescence system based on europium chelate as a fluorescent marker. The system performance was tested with the immunoassay based on the cardiac marker, TnI. The same signal-to-noise ratio as for the flash lamp based system was obtained, operating the LED below specified maximum current. The background counts of the system and its main contributors were measured and analyzed. The background of the system of the LED based unit was improved by 39% compared to that of the Xenon flash lamp based unit, due to the LEDs narrower emission spectrum and longer pulse width. Key parameters of the LED system are discussed to further optimize the signal-to-noise ratio and signal-to-background, and hence the sensitivity of the instrument.

Spectroscopic measurements of muzzle flash plasma

NASA Astrophysics Data System (ADS)

Uglum, J. R.

1986-11-01

The experimental apparatus and sample data for the muzzle flash plasma of a laboratory-scale railgun are described. Theoretical predictions for the railgun system configuration used indicated that 24 kJ of energy would be dissipated by the muzzle flash. Spectral data were recorded with a spectrograph sensing through a slit and a PIN diode, the latter to obtain temporal resolution in the data. The tests featured a plastic projectile with an Al foil armature. The measurements identified Cu as the dominant flash material, ablated from the rails in the barrel.

Bayer Digester Optimization Studies using Computer Techniques

NASA Astrophysics Data System (ADS)

Kotte, Jan J.; Schleider, Victor H.

Theoretically required heat transfer performance by the multistaged flash heat reclaim system of a high pressure Bayer digester unit is determined for various conditions of discharge temperature, excess flash vapor and indirect steam addition. Solution of simultaneous heat balances around the digester vessels and the heat reclaim system yields the magnitude of available heat for representation of each case on a temperature-enthalpy diagram, where graphical fit of the number of flash stages fixes the heater requirements. Both the heat balances and the trial-and-error graphical solution are adapted to solution by digital computer techniques.

The Economic Potential of Two Nuclear-Renewable Hybrid Energy Systems

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

Ruth, Mark; Cutler, Dylan; Flores-Espino, Francisco

Tightly coupled nuclear-renewable hybrid energy systems (N-R HESs) are an option that can generate zero-carbon, dispatchable electricity and provide zero-carbon energy for industrial processes at a lower cost than alternatives. N-R HESs are defined as systems that are managed by a single entity and link a nuclear reactor that generates heat, a thermal power cycle for heat to electricity conversion, at least one renewable energy source, and an industrial process that uses thermal and/or electrical energy. This report provides results of an analysis of two N-R HES scenarios. The first is a Texas-synthetic gasoline scenario that includes four subsystems: amore » nuclear reactor, thermal power cycle, wind power plant, and synthetic gasoline production technology. The second is an Arizona-desalination scenario with its four subsystems a nuclear reactor, thermal power cycle, solar photovoltaics, and a desalination plant. The analysis focuses on the economics of the N-R HESs and how they compare to other options, including configurations without all the subsystems in each N-R HES and alternatives where the energy is provided by natural gas.« less

Indirect contact freeze water desalination for an ice maker machine - CFD simulation

NASA Astrophysics Data System (ADS)

Jayakody, Harith; Al-Dadah, Raya; Mahmoud, Saad

2017-11-01

To offer for potable water shortages, sea water desalination is a potential solution for the global rising demand for fresh water. The latent heat of fusion is about one-seventh the latent heat of vaporisation, thus indicating the benefit of lower energy consumption for the freeze desalination process. Limited literature is reported on computational fluid dynamics (CFD) on freeze desalination. Therefore, analysing and investigating thermodynamic processes are easily conducted by the powerful tool of CFD. A single unit of ice formation in an ice maker machine was modelled using ANSYS Fluent software three-dimensionally. Energy, species transport and solidification/melting modules were used in building the CFD model. Parametric analysis was conducted using the established CFD model to predict the effects of freezing temperature and the geometry of the ice maker machine; on ice production and the freezing time. Lower freezing temperatures allowed more ice production and faster freezing. Increasing the diameter and the length of the freezing tube enabled more ice to be produced.

Effects of high salinity from desalination brine on growth, photosynthesis, water relations and osmolyte concentrations of seagrass Posidonia australis.

PubMed

Cambridge, M L; Zavala-Perez, A; Cawthray, G R; Mondon, J; Kendrick, G A

2017-02-15

Highly saline brines from desalination plants expose seagrass communities to salt stress. We examined effects of raised salinity (46 and 54psu) compared with seawater controls (37psu) over 6weeks on the seagrass, Posidonia australis, growing in tanks with the aim of separating effects of salinity from other potentially deleterious components of brine and determining appropriate bioindicators. Plants survived exposures of 2-4weeks at 54psu, the maximum salinity of brine released from a nearby desalination plant. Salinity significantly reduced maximum quantum yield of PSII (chlorophyll a fluorescence emissions). Leaf water potential (Ψ w ) and osmotic potential (Ψ π ) were more negative at increased salinity, while turgor pressure (Ψ p ) was unaffected. Leaf concentrations of K + and Ca 2+ decreased, whereas concentrations of sugars (mainly sucrose) and amino acids increased. We recommend leaf osmolarity, ion, sugar and amino acid concentrations as bioindicators for salinity effects, associated with brine released in desalination plant outfalls. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of New Water Sources on the Overall Water Network: An Optimisation Approach

PubMed Central

Jones, Brian C.; Hove-Musekwa, Senelani D.

2014-01-01

A mathematical programming problem is formulated for a water network with new water sources included. Salinity and water hardness are considered in the model, which is later solved using the Max-Min Ant System (MMAS) to assess the impact of new water sources on the total cost of the existing network. It is efficient to include new water sources if the distances to them are short or if there is a high penalty associated with failure to meet demand. Desalination unit costs also significantly affect the decision whether to install new water sources into the existing network while softening costs are generally negligible in making such decisions. Experimental results show that, in the example considered, it is efficient to reduce number of desalination plants to remain with one central plant. The Max-Min Ant System algorithm seems to be an effective method as shown by least computational time as compared to the commercial solver Cplex. PMID:27382617

Molecular dynamics simulation of salt rejection through silicon carbide nanotubes as a nanostructure membrane.

PubMed

Khataee, Alireza; Bayat, Golchehreh; Azamat, Jafar

2017-01-01

Salt rejection phenomenon was investigated using armchair silicon carbide (SiC) nanotubes under applied electric fields. The systems included the (7,7) and (8,8) SiC nanotubes surrounded by silicon nitride membrane immersed in a 0.4mol/L aqueous solution of sodium chloride. Results of molecular dynamics (MD) simulations for selective separation of Na + and Cl - ions showed that the (7,7) SiC nanotube is suitable for separation of cations and the (8,8) SiC nanotube can be used for separating anions. The water desalination by SiC nanotubes was demonstrated by potential of mean force for Na + and Cl - ions in each SiC nanotube. Furthermore, the ionic current, ion residence time, and the radial distribution functions of species were measured to evaluate the properties of the system. Based on the results of this research, the studied SiC nanotubes can be recommended as a nanostructure model for water desalination. Copyright © 2016 Elsevier Inc. All rights reserved.

The potential contribution of geothermal energy to electricity supply in Saudi Arabia

NASA Astrophysics Data System (ADS)

Chandrasekharam, D.; Lashin, Aref; Al Arifi, Nassir

2016-10-01

With increase in demand for electricity at 7.5% per year, the major concern of Saudi Arabia is the amount of CO2 being emitted. The country has the potential of generating 200×106 kWh from hydrothermal sources and 120×106 terawatt hour from Enhanced Geothermal System (EGS) sources. In addition to electricity generation and desalination, the country has substantial source for direct application such as space cooling and heating, a sector that consumes 80% of the electricity generated from fossil fuels. Geothermal energy can offset easily 17 million kWh of electricity that is being used for desalination. At least a part of 181,000 Gg of CO2 emitted by conventional space cooling units can also be mitigated through ground-source heat pump technology immediately. Future development of EGS sources together with the wet geothermal systems will make the country stronger in terms of oil reserves saved and increase in exports.

Multi-objective Optimization of a Solar Humidification Dehumidification Desalination Unit

NASA Astrophysics Data System (ADS)

Rafigh, M.; Mirzaeian, M.; Najafi, B.; Rinaldi, F.; Marchesi, R.

2017-11-01

In the present paper, a humidification-dehumidification desalination unit integrated with solar system is considered. In the first step mathematical model of the whole plant is represented. Next, taking into account the logical constraints, the performance of the system is optimized. On one hand it is desired to have higher energetic efficiency, while on the other hand, higher efficiency results in an increment in the required area for each subsystem which consequently leads to an increase in the total cost of the plant. In the present work, the optimum solution is achieved when the specific energy of the solar heater and also the areas of humidifier and dehumidifier are minimized. Due to the fact that considered objective functions are in conflict, conventional optimization methods are not applicable. Hence, multi objective optimization using genetic algorithm which is an efficient tool for dealing with problems with conflicting objectives has been utilized and a set of optimal solutions called Pareto front each of which is a tradeoff between the mentioned objectives is generated.

Desalination of Walls and Façades

NASA Astrophysics Data System (ADS)

Wedekind, W.; Jáuregui Arreola, K.; Siegesmund, S.

2012-04-01

For large monumental objects like walls and façades, the common technique of applying poultices for desalination often are not effective. This practice is neither cost effective nor does it lead to the desired result of desalination. To manage the conservation and desalination of these kinds of objects, several sprinkling techniques are known and have been applied on historical objects. For example, in the wooden warship Vasa, which was excavated from the sea bottom in Stockholm/Sweden, a sprinkling method was applied in 1961 for conservation and desalination. A sprinkling method to desalinate porous mineral materials will be presented using three different case studies: the rock cut monument no. 825 in Petra/Jordan, the medieval monastary church of the former Franziscan convent in Zeitz/Germany and the baroque monastary church Santa Monica in Guadalajara/Mexico. Before to start with practical conservation, the material- and petropysical properties, focoussed on water transport properties, like porosity, pore size distribution, water uptake and drying rate were investigadet. Diagnostic investigations on the objects included the mapping of deterioration, moister content measurements and salt accumulation determined by borehole cuts samples at depth. In the sprinkling method water is sprayed onto the wall surface through nozzels arranged in a modular grid. Depending on the sprinkling duration, a small or a large amount of water seeps into the porous materials, whereby the depth penetration can be adjusted accordingly. The water not absorbed by the stone runs off the facade and can be collected in liter amounts and tested by electrical conductivity with respect to the dissolved substances. After the drying of the wall's surface and the accumulation of salt at the material's surface, the procedure is repeated. For each subsequent washing a lower content of salt should be brought to the surface. Step by step the salt concentration will eventually decrease to almost zero. By application of the sprinkling method several thousand grams of soluble salts can be extracted. A significant reduction of the salt content within the stone can be detected by drilling dust analyses. The specific situation of salt-accumulation and weathering will be illustrated in each case, along with a presentation of the results and the difficulties and experiences of practical desalination.

A first look at global flash drought: long term change and short term predictability

NASA Astrophysics Data System (ADS)

Yuan, Xing; Wang, Linying; Ji, Peng

2017-04-01

"Flash drought" became popular after the unexpected 2012 central USA drought, mainly due to its rapid development, low predictability and devastating impacts on water resources and crop yields. A pilot study by Mo and Lettenmaier (2015) found that flash drought, based on a definition of concurrent heat extreme, soil moisture deficit and evapotranspiration (ET) enhancement at pentad scale, were in decline over USA during recent 100 years. Meanwhile, a recent work indicated that the occurrence of flash drought in China was doubled during the past 30 years, where a severe flash drought in the summer of 2013 ravaged 13 provinces in southern China. As global warming increases the frequency of heat waves and accelerates the hydrological cycle, the flash drought is expected to increase in general, but its trend might also be affected by interannual to decadal climate oscillations. To consolidate the hotspots of flash drought and the effects of climate change on flash drought, a global inventory is being conducted by using multi-source observations (in-situ, satellite and reanalysis), CMIP5 historical simulations and future projections under different forcing scenarios, as well as global land surface hydrological modeling for key variables including surface air temperature, soil moisture and ET. In particular, a global picture of the flash drought distribution, the contribution of naturalized and anthropogenic forcings to global flash drought change, and the risk of global flash drought in the future, will be presented. Besides investigating the long-term change of flash drought, providing reliable early warning is also essential to developing adaptation strategies. While regional drought early warning systems have been emerging in recent decade, forecasting of flash drought is still at an exploratory stage due to limited understanding of flash drought predictability. Here, a set of sub-seasonal to seasonal (S2S) hindcast datasets are being used to assess the short term predictability of flash drought via a perfect model assumption.

33 CFR 118.110 - Daymarks and lateral lighting on bridges.

Code of Federal Regulations, 2012 CFR

2012-07-01

... through bridges with U.S. aids to navigation system lateral marks and lights installed on the... flashing, flashing, isophase or occulting red and green lights to mark the main channels. (b) If lateral system lights are required or authorized to mark the main navigation channels, fixed yellow lights shall...

33 CFR 118.110 - Daymarks and lateral lighting on bridges.

Code of Federal Regulations, 2013 CFR

2013-07-01

... through bridges with U.S. aids to navigation system lateral marks and lights installed on the... flashing, flashing, isophase or occulting red and green lights to mark the main channels. (b) If lateral system lights are required or authorized to mark the main navigation channels, fixed yellow lights shall...

33 CFR 118.110 - Daymarks and lateral lighting on bridges.

Code of Federal Regulations, 2014 CFR

2014-07-01

... through bridges with U.S. aids to navigation system lateral marks and lights installed on the... flashing, flashing, isophase or occulting red and green lights to mark the main channels. (b) If lateral system lights are required or authorized to mark the main navigation channels, fixed yellow lights shall...

Evaluation of a rectangular rapid flashing beacon system at the Belmont Ridge Road and W&OD Trail mid-block crosswalk.

DOT National Transportation Integrated Search

2015-05-01

On April 8, 2013, the Virginia Department of Transportation (VDOT) installed a Rectangular Rapid Flashing Beacon : (RRFB) system at Belmont Ridge Road in Loudoun County that included two units at the Washington and Old Dominion : (W&OD) Trail crossin...

Water recovery from brines and salt-saturated solutions: operability and thermodynamic efficiency considerations for desalination technologies

EPA Science Inventory

This review provides an overview of desalination technologies and discusses the thermodynamic efficiencies and operational issues associated with the various technologies particularly with regard to high salinity streams. When water is recovered from a saline source, a brine conc...

Calibration of High Temperature Thermal Conductivity System: New Algorithm to Measure Heat Capacity Using Flash Thermal Diffusivity in Thermoelectric Materials

NASA Technical Reports Server (NTRS)

Deb, Rahul; Snyder, Jeff G.

2005-01-01

A viewgraph presentation describing thermoelectric materials, an algorithm for heat capacity measurements and the process of flash thermal diffusivity. The contents include: 1) What are Thermoelectrics?; 2) Thermoelectric Applications; 3) Improving Thermoelectrics; 4) Research Goal; 5) Flash Thermal Diffusivity; 6) Background Effects; 7) Stainless Steel Comparison; 8) Pulse Max Integral; and 9) Graphite Comparison Algorithm.

Improving bioelectricity generation and COD removal of sewage sludge in microbial desalination cell.

PubMed

Ebrahimi, Atieh; Yousefi Kebria, Daryoush; Darzi, Ghasem Najafpour

2018-05-01

Improving wastewater treatment process and water desalination are two important solutions for increasing the available supply of fresh water. Microbial desalination cells (MDCs) with common electrolytes display relatively low organic matter removal and high cost. In this study, sewage sludge was used as the substrate in the Microbial desalination cell (MDC) under three different initial salt concentrations (5, 20 and 35 g.L -1 ) and the maximum salt removal rates of 50.6%, 64% and 69.6% were obtained under batch condition, respectively. The MDC also produced the maximum power density of 47.1 W m -3 and the averaged chemical oxygen demand (COD) removal of 58.2 ± 0.89% when the initial COD was 6610 ± 83 mg L -1 . Employing treated sludge as catholyte enhanced COD removal and power density to 87.3% and 54.4 W m -3 , respectively, with counterbalancing pH variation in treated effluent. These promising results showed, for the first time, that the excess sewage sludge obtained from biological wastewater treatment plants could be successfully used as anolyte and catholyte in MDC, achieving organic matter biodegradation along with salt removal and energy production. In addition, using treated sludge as catholyte will improve the performance of MDC and introduce a more effective method for both sludge treatment and desalination.

Status of the photomultiplier-based FlashCam camera for the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Pühlhofer, G.; Bauer, C.; Eisenkolb, F.; Florin, D.; Föhr, C.; Gadola, A.; Garrecht, F.; Hermann, G.; Jung, I.; Kalekin, O.; Kalkuhl, C.; Kasperek, J.; Kihm, T.; Koziol, J.; Lahmann, R.; Manalaysay, A.; Marszalek, A.; Rajda, P. J.; Reimer, O.; Romaszkan, W.; Rupinski, M.; Schanz, T.; Schwab, T.; Steiner, S.; Straumann, U.; Tenzer, C.; Vollhardt, A.; Weitzel, Q.; Winiarski, K.; Zietara, K.

2014-07-01

The FlashCam project is preparing a camera prototype around a fully digital FADC-based readout system, for the medium sized telescopes (MST) of the Cherenkov Telescope Array (CTA). The FlashCam design is the first fully digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for digitization and triggering, and a high performance camera server as back end. It provides the option to easily implement different types of trigger algorithms as well as digitization and readout scenarios using identical hardware, by simply changing the firmware on the FPGAs. The readout of the front end modules into the camera server is Ethernet-based using standard Ethernet switches and a custom, raw Ethernet protocol. In the current implementation of the system, data transfer and back end processing rates of 3.8 GB/s and 2.4 GB/s have been achieved, respectively. Together with the dead-time-free front end event buffering on the FPGAs, this permits the cameras to operate at trigger rates of up to several ten kHz. In the horizontal architecture of FlashCam, the photon detector plane (PDP), consisting of photon detectors, preamplifiers, high voltage-, control-, and monitoring systems, is a self-contained unit, mechanically detached from the front end modules. It interfaces to the digital readout system via analogue signal transmission. The horizontal integration of FlashCam is expected not only to be more cost efficient, it also allows PDPs with different types of photon detectors to be adapted to the FlashCam readout system. By now, a 144-pixel mini-camera" setup, fully equipped with photomultipliers, PDP electronics, and digitization/ trigger electronics, has been realized and extensively tested. Preparations for a full-scale, 1764 pixel camera mechanics and a cooling system are ongoing. The paper describes the status of the project.

First Lightning Flashes on Saturn

NASA Image and Video Library

2010-04-14

NASA Cassini spacecraft captured the first lightning flashes on Saturn. The storm that generated the lightning lasted from January to October 2009, making it the longest-lasting lightning storm known in the solar system.

CLOSED-CYCLE TEXTILE DYEING: FULL-SCALE HYPERFILTRATION DEMONSTRATION

EPA Science Inventory

The report gives results of a project of joining a full-scale dynamic-membrane hyperfiltration (HF) system with an operating dye range. (HF is a membrane separation technique that has been used successfully to desalinate natural water. The dye range is a multi-purpose unit with a...

Membrane-spacer assembly for flow-electrode capacitive deionization

NASA Astrophysics Data System (ADS)

Lee, Ki Sook; Cho, Younghyun; Choo, Ko Yeon; Yang, SeungCheol; Han, Moon Hee; Kim, Dong Kook

2018-03-01

Flow-electrode capacitive deionization (FCDI) is a desalination process designed to overcome the limited desalination capacity of conventional CDI systems due to their fixed electrodes. Such a FCDI cell system is comprised of a current collector, freestanding ion-exchange membrane (IEM), gasket, and spacer for flowing saline water. To simplify the cell system, in this study we combined the membrane and spacer into a single unit, by coating the IEM on a porous ceramic structure that acts as the spacer. The combination of membrane with the porous structure avoids the use of costly freestanding IEM. Furthermore, the FCDI system can be readily scaled up by simply inserting the IEM-coated porous structures in between the channels for flow electrodes. However, coating the IEM on such porous ceramic structures can cause a sudden drop in the treatment capacity, if the coated IEM penetrates the ceramic pores and prevents these pores from acting as saline flow channels. To address this issue, we blocked the larger microscale pores on the outer surface with SiO2 and polymeric multilayers. Thus, the IEM is coated only onto the top surface of the porous structure, while the internal pores remain empty to function as water channels.

IMPROVING THE QUALITY, AVAILABILITY AND SUSTAINABILITY OF DRINKING WATER SUPPLIES THROUGH ANTIFOULING AND ANTISCALING DESALINATION MEMBRANES

EPA Science Inventory

Surface modification with the selected polymers is expected to reduce the fouling and scaling propensity of desalination membranes by strongly binding water at the membrane surface. Foulants will interact with this bound water layer and not with the membrane surface itself....

Desalination. LC Science Tracer Bullet.

ERIC Educational Resources Information Center

Buydos, John F., Comp.

This guide provides a review of the relevant literature on desalination within the collections of the Library of Congress. While not intended as a comprehensive bibliography, this guide is designed as a quick and ready reference source for the reader, and includes the following sections: (1) articles that provide introductions to the topic of…

Imaging Flash Lidar for Safe Landing on Solar System Bodies and Spacecraft Rendezvous and Docking

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin; Roback, Vincent E.; Bulyshev, Alexander E.; Brewster, Paul F.; Carrion, William A; Pierrottet, Diego F.; Hines, Glenn D.; Petway, Larry B.; Barnes, Bruce W.; Noe, Anna M.

2015-01-01

NASA has been pursuing flash lidar technology for autonomous, safe landing on solar system bodies and for automated rendezvous and docking. During the final stages of the landing from about 1 kilometer to 500 meters above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard flight computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16,000 pixels range images with 7 centimeters precision, at 20 Hertz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument and presents the results of recent flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus) built by NASA Johnson Space Center. The flights were conducted at a simulated lunar terrain site, consisting of realistic hazard features and designated landing areas, built at NASA Kennedy Space Center specifically for this demonstration test. This paper also provides an overview of the plan for continued advancement of the flash lidar technology aimed at enhancing its performance to meet both landing and automated rendezvous and docking applications.

FLASH fly-by-light flight control demonstration results overview

NASA Astrophysics Data System (ADS)

Halski, Don J.

1996-10-01

The Fly-By-Light Advanced Systems Hardware (FLASH) program developed Fly-By-Light (FBL) and Power-By-Wire (PBW) technologies for military and commercial aircraft. FLASH consists of three tasks. Task 1 developed the fiber optic cable, connectors, testers and installation and maintenance procedures. Task 3 developed advanced smart, rotary thin wing and electro-hydrostatic (EHA) actuators. Task 2, which is the subject of this paper,l focused on integration of fiber optic sensors and data buses with cable plant components from Task 1 and actuators from Task 3 into centralized and distributed flight control systems. Both open loop and piloted hardware-in-the-loop demonstrations were conducted with centralized and distributed flight control architectures incorporating the AS-1773A optical bus, active hand controllers, optical sensors, optimal flight control laws in high speed 32-bit processors, and neural networks for EHA monitoring and fault diagnosis. This paper overviews the systems level testing conducted under the FLASH Flight Control task. Preliminary results are summarized. Companion papers provide additional information.

Moving target detection in flash mode against stroboscopic mode by active range-gated laser imaging

NASA Astrophysics Data System (ADS)

Zhang, Xuanyu; Wang, Xinwei; Sun, Liang; Fan, Songtao; Lei, Pingshun; Zhou, Yan; Liu, Yuliang

2018-01-01

Moving target detection is important for the application of target tracking and remote surveillance in active range-gated laser imaging. This technique has two operation modes based on the difference of the number of pulses per frame: stroboscopic mode with the accumulation of multiple laser pulses per frame and flash mode with a single shot of laser pulse per frame. In this paper, we have established a range-gated laser imaging system. In the system, two types of lasers with different frequency were chosen for the two modes. Electric fan and horizontal sliding track were selected as the moving targets to compare the moving blurring between two modes. Consequently, the system working in flash mode shows more excellent performance in motion blurring against stroboscopic mode. Furthermore, based on experiments and theoretical analysis, we presented the higher signal-to-noise ratio of image acquired by stroboscopic mode than flash mode in indoor and underwater environment.

Multi-stage flash degaser

DOEpatents

Rapier, P.M.

1980-06-26

A multi-stage flash degaser is incorporated in an energy conversion system having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger in order that the heat exchanger and a turbine and condenser of the system can operate at optimal efficiency.

Temporal characterization of small arms muzzle flash in the broadband visible

NASA Astrophysics Data System (ADS)

Burke, Tom; Bratlie, Duane

2010-04-01

The authors have developed a simple system for characterizing the muzzle flash duration of common military small-arms ammunition as a feeder for system design configurations. This paper is a synopsis of the efforts and results of the effort to characterize the broadband optical signature of modern small arms.

Gun muzzle flash detection using a CMOS single photon avalanche diode

NASA Astrophysics Data System (ADS)

Merhav, Tomer; Savuskan, Vitali; Nemirovsky, Yael

2013-10-01

Si based sensors, in particular CMOS Image sensors, have revolutionized low cost imaging systems but to date have hardly been considered as possible candidates for gun muzzle flash detection, due to performance limitations, and low SNR in the visible spectrum. In this study, a CMOS Single Photon Avalanche Diode (SPAD) module is used to record and sample muzzle flash events in the visible spectrum, from representative weapons, common on the modern battlefield. SPADs possess two crucial properties for muzzle flash imaging - Namely, very high photon detection sensitivity, coupled with a unique ability to convert the optical signal to a digital signal at the source pixel, thus practically eliminating readout noise. This enables high sampling frequencies in the kilohertz range without SNR degradation, in contrast to regular CMOS image sensors. To date, the SPAD has not been utilized for flash detection in an uncontrolled environment, such as gun muzzle flash detection. Gun propellant manufacturers use alkali salts to suppress secondary flashes ignited during the muzzle flash event. Common alkali salts are compounds based on Potassium or Sodium, with spectral emission lines around 769nm and 589nm, respectively. A narrow band filter around the Potassium emission doublet is used in this study to favor the muzzle flash signal over solar radiation. This research will demonstrate the SPAD's ability to accurately sample and reconstruct the temporal behavior of the muzzle flash in the visible wavelength under the specified imaging conditions. The reconstructed signal is clearly distinguishable from background clutter, through exploitation of flash temporal characteristics.

Toward seamless high-resolution flash flood forecasting over Europe based on radar nowcasting and NWP: An evaluation with case studies

NASA Astrophysics Data System (ADS)

Park, Shinju; Berenguer, Marc; Sempere-Torres, Daniel; Baugh, Calum; Smith, Paul

2017-04-01

Flash floods induced by heavy rain are one of the hazardous natural events that significantly affect human lives. Because flash floods are characterized by their rapid onset, forecasting flash flood to lead an effective response requires accurate rainfall predictions with high spatial and temporal resolution and adequate representation of the hydrologic and hydraulic processes within a catchment that determine rainfall-runoff accumulations. We present extreme flash flood cases which occurred throughout Europe in 2015-2016 that were identified and forecasted by two real-time approaches: 1) the European Rainfall-Induced Hazard Assessment System (ERICHA) and 2) the European Runoff Index based on Climatology (ERIC). ERICHA is based on the nowcasts of accumulated precipitation generated from the pan-European radar composites produced by the EUMETNET project OPERA. It has the advantage of high-resolution precipitation inputs and rapidly updated forecasts (every 15 minutes), but limited forecast lead time (up to 8 hours). ERIC, on the other hand, provides 5-day forecasts based on the COSMO-LEPS NWP simulations updated 2 times a day but is only produced at a 7 km resolution. We compare the products from both systems and focus on showing the advantages, limitations and complementarities of ERICHA and ERIC for seamless high-resolution flash flood forecasting.

An assessment of the use of skin flashes in helical tomotherapy using phantom and in-vivo dosimetry.

PubMed

Tournel, Koen; Verellen, Dirk; Duchateau, Michael; Fierens, Yves; Linthout, Nadine; Reynders, Truus; Voordeckers, Mia; Storme, Guy

2007-07-01

In helical tomotherapy the nature of the optimizing and planning systems allows the delivery of dose on the skin using a build-up compensating technique (skin flash). However, positioning errors or changes in the patient's contour can influence the correct dosage in these regions. This work studies the behavior of skin-flash regions using phantom and in-vivo dosimetry. The dosimetric accuracy of the tomotherapy planning system in skin-flash regions is checked using film and TLD on phantom. Positioning errors are induced and the effect on the skin dose is investigated. Further a volume decrease is simulated using bolus material and the results are compared. Results show that the tomotherapy planning system calculates dose on skin regions within 2 SD using TLD measurements. Film measurements show drops of dose of 2.8% and 26% for, respectively, a 5mm and 10mm mispositioning of the phantom towards air and a dose increase of 9% for a 5mm shift towards tissue. These measurements are confirmed by TLD measurements. A simulated volume reduction shows a similar behavior with a 2.6% and 19.4% drop in dose, measured with TLDs. The tomotherapy system allows adequate planning and delivery of dose using skin flashes. However, exact positioning is crucial to deliver the dose at the exact location.

Sertac Akar | NREL

Science.gov Websites

Sertac Akar Photo of Sertac Akar Sertac Akar Energy Analyst - Geothermal Sertac.Akar@nrel.gov | 303 systems (GIS) and remote sensing (RS) Research Interests Techno-economic analysis of geothermal energy resource assessment (exploration & production) Desalination of brackish water using geothermal energy

2. SECTIONAL BOILER '#4 IDEAL RED FLASH.' Hot Springs ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. SECTIONAL BOILER '#4 IDEAL RED FLASH.' - Hot Springs National Park, Bathhouse Row, Ozark Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

The Flash ADC system and PMT waveform reconstruction for the Daya Bay experiment

NASA Astrophysics Data System (ADS)

Huang, Yongbo; Chang, Jinfan; Cheng, Yaping; Chen, Zhang; Hu, Jun; Ji, Xiaolu; Li, Fei; Li, Jin; Li, Qiuju; Qian, Xin; Jetter, Soeren; Wang, Wei; Wang, Zheng; Xu, Yu; Yu, Zeyuan

2018-07-01

To better understand the energy response of the Antineutrino Detector (AD), the Daya Bay Reactor Neutrino Experiment installed a full Flash ADC readout system on one AD that allowed for simultaneous data taking with the current readout system. This paper presents the design, data acquisition, and simulation of the Flash ADC system, and focuses on the PMT waveform reconstruction algorithms. For liquid scintillator calorimetry, the most critical requirement to waveform reconstruction is linearity. Several common reconstruction methods were tested but the linearity performance was not satisfactory. A new method based on the deconvolution technique was developed with 1% residual non-linearity, which fulfills the requirement. The performance was validated with both data and Monte Carlo (MC) simulations, and 1% consistency between them has been achieved.

Performance verification of the FlashCam prototype camera for the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Werner, F.; Bauer, C.; Bernhard, S.; Capasso, M.; Diebold, S.; Eisenkolb, F.; Eschbach, S.; Florin, D.; Föhr, C.; Funk, S.; Gadola, A.; Garrecht, F.; Hermann, G.; Jung, I.; Kalekin, O.; Kalkuhl, C.; Kasperek, J.; Kihm, T.; Lahmann, R.; Marszalek, A.; Pfeifer, M.; Principe, G.; Pühlhofer, G.; Pürckhauer, S.; Rajda, P. J.; Reimer, O.; Santangelo, A.; Schanz, T.; Schwab, T.; Steiner, S.; Straumann, U.; Tenzer, C.; Vollhardt, A.; Wolf, D.; Zietara, K.; CTA Consortium

2017-12-01

The Cherenkov Telescope Array (CTA) is a future gamma-ray observatory that is planned to significantly improve upon the sensitivity and precision of the current generation of Cherenkov telescopes. The observatory will consist of several dozens of telescopes with different sizes and equipped with different types of cameras. Of these, the FlashCam camera system is the first to implement a fully digital signal processing chain which allows for a traceable, configurable trigger scheme and flexible signal reconstruction. As of autumn 2016, a prototype FlashCam camera for the medium-sized telescopes of CTA nears completion. First results of the ongoing system tests demonstrate that the signal chain and the readout system surpass CTA requirements. The stability of the system is shown using long-term temperature cycling.

A low power flash-FPGA based brain implant micro-system of PID control.

PubMed

Lijuan Xia; Fattah, Nabeel; Soltan, Ahmed; Jackson, Andrew; Chester, Graeme; Degenaar, Patrick

2017-07-01

In this paper, we demonstrate that a low power flash FPGA based micro-system can provide a low power programmable interface for closed-loop brain implant inter- faces. The proposed micro-system receives recording local field potential (LFP) signals from an implanted probe, performs closed-loop control using a first order control system, then converts the signal into an optogenetic control stimulus pattern. Stimulus can be implemented through optoelectronic probes. The long term target is for both fundamental neuroscience applications and for clinical use in treating epilepsy. Utilizing our device, closed-loop processing consumes only 14nJ of power per PID cycle compared to 1.52μJ per cycle for a micro-controller implementation. Compared to an application specific digital integrated circuit, flash FPGA's are inherently programmable.

Maskless, reticle-free, lithography

DOEpatents

Ceglio, N.M.; Markle, D.A.

1997-11-25

A lithography system in which the mask or reticle, which usually carries the pattern to be printed onto a substrate, is replaced by a programmable array of binary (i.e. on/off) light valves or switches which can be programmed to replicate a portion of the pattern each time an illuminating light source is flashed. The pattern of light produced by the programmable array is imaged onto a lithographic substrate which is mounted on a scanning stage as is common in optical lithography. The stage motion and the pattern of light displayed by the programmable array are precisely synchronized with the flashing illumination system so that each flash accurately positions the image of the pattern on the substrate. This is achieved by advancing the pattern held in the programmable array by an amount which corresponds to the travel of the substrate stage each time the light source flashes. In this manner the image is built up of multiple flashes and an isolated defect in the array will only have a small effect on the printed pattern. The method includes projection lithographies using radiation other than optical or ultraviolet light. The programmable array of binary switches would be used to control extreme ultraviolet (EUV), x-ray, or electron, illumination systems, obviating the need for stable, defect free masks for projection EUV, x-ray, or electron, lithographies. 7 figs.

Maskless, reticle-free, lithography

DOEpatents

Ceglio, Natale M.; Markle, David A.

1997-11-25

A lithography system in which the mask or reticle, which usually carries the pattern to be printed onto a substrate, is replaced by a programmable array of binary (i.e. on/off) light valves or switches which can be programmed to replicate a portion of the pattern each time an illuminating light source is flashed. The pattern of light produced by the programmable array is imaged onto a lithographic substrate which is mounted on a scanning stage as is common in optical lithography. The stage motion and the pattern of light displayed by the programmable array are precisely synchronized with the flashing illumination system so that each flash accurately positions the image of the pattern on the substrate. This is achieved by advancing the pattern held in the programmable array by an amount which corresponds to the travel of the substrate stage each time the light source flashes. In this manner the image is built up of multiple flashes and an isolated defect in the array will only have a small effect on the printed pattern. The method includes projection lithographies using radiation other than optical or ultraviolet light. The programmable array of binary switches would be used to control extreme ultraviolet (EUV), x-ray, or electron, illumination systems, obviating the need for stable, defect free masks for projection EUV, x-ray, or electron, lithographies.

Sustainable water desalination and electricity generation in a separator coupled stacked microbial desalination cell with buffer free electrolyte circulation.

PubMed

Chen, Xi; Liang, Peng; Wei, Zhimou; Zhang, Xiaoyuan; Huang, Xia

2012-09-01

A separator coupled circulation stacked microbial desalination cell (c-SMDC-S) was constructed to stabilize the pH imbalances in MDCs without buffer solution and achieved the stable desalination. The long-term operation of c-SMDC-S, regular stacked MDC (SMDC) and no separator coupled circulation SMDC (c-SMDC) were tested. The SMDC and c-SMDC could only stably operate for 1 week and 1 month owing to dramatic anolyte pH decrease and serious biofilm growth on the air cathode, respectively. The c-SMDC-S gained in anolyte alkalinity and operated stably for about 60 days without the thick biofilm growth on cathode. Besides, the chemical oxygen demand removal and coulombic efficiency were 64 ± 6% and 30 ± 2%, higher than that of SMDC and c-SMDC, respectively. It was concluded that the circulation of alkalinity could remove pH imbalance while the separator could expand the operation period and promote the conversion of organic matter to electricity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nanotechnology applications to desalination : a report for the joint water reuse & desalination task force.

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

Brady, Patrick Vane; Mayer, Tom; Cygan, Randall Timothy

2011-01-01

Nanomaterials and nanotechnology methods have been an integral part of international research over the past decade. Because many traditional water treatment technologies (e.g. membrane filtration, biofouling, scale inhibition, etc.) depend on nanoscale processes, it is reasonable to expect one outcome of nanotechnology research to be better, nano-engineered water treatment approaches. The most immediate, and possibly greatest, impact of nanotechnology on desalination methods will likely be the development of membranes engineered at the near-molecular level. Aquaporin proteins that channel water across cell membranes with very low energy inputs point to the potential for dramatically improved performance. Aquaporin-laced polymer membranes and aquaporin-mimickingmore » carbon nanotubes and metal oxide membranes developed in the lab support this. A critical limitation to widespread use of nanoengineered desalination membranes will be their scalability to industrial fabrication processes. Subsequent, long-term improvements in nanoengineered membranes may result in self-healing membranes that ideally are (1) more resistant to biofouling, (2) have biocidal properties, and/or (3) selectively target trace contaminants.« less

Review of Knowledge on the Occurrence, Chemical Composition, and Potential Use for Desalination of Saline Ground Water in Arizona, New Mexico, and Texas with a Discussion of Potential Future Study Needs

USGS Publications Warehouse

Huff, G.F.

2004-01-01

Increasing demand on the limited supplies of freshwater in the desert Southwest, as well as other parts of the United States, has increased the level of interest in saline-water resources. Saline ground water has long been recognized as a potentially important contributor to water supply in the Southwest, as demonstrated by the number of hydrologic, geologic, and engineering studies on the distribution of saline water and the feasibility of desalination. Potential future study needs include investigating and documenting the three-dimensional distribution of salinity and chemical composition of saline-water resources and the hydraulic properties of aquifers containing these saline-water resources, assessing the chemical suitability of saline water for use with existing and anticipated desalination technologies, simulating the effect of withdrawal of saline ground water on water levels and water composition in saline and adjoining or overlying freshwater aquifers, and determining the suitability of target geologic formations for injection of desalination-generated waste.

An assessment of Spain's Programa AGUA and its implications for sustainable water management in the province of Almería, southeast Spain.

PubMed

Downward, Stuart R; Taylor, Ros

2007-01-01

Spain's Programa AGUA was proposed in 2004 as a replacement for the Spanish National Hydrological Plan and represented a fundamental policy shift in national water management from large inter-basin water transfers to a commitment to desalination. Twenty-one desalination facilities are planned for six provinces on the Spanish Mediterranean coast to supplement their water needs. These include the province of Almería that for the last 30 years has endured a net water abstraction overdraft leading to serious reservoir depletion and groundwater imbalances. Rising water use is a result of increasing demand to support irrigated agriculture (e.g. greenhouse horticulture) and for domestic needs (e.g. rapid urban growth and tourism development), which has led observers to question Almería's long-term water sustainability. Desalinated water alone is unlikely to be sufficient to make up these water deficits and water-users will have to accept a move to full-price water recovery by 2010 under the European Union (EU) Water Framework Directive of which Spain is a signatory. Anticipated water efficiencies resulting from higher water tariffs, increasing water reuse and water infrastructure improvements (including inter-basin transfers), in conjunction with increasing use of desalinated water, are expected to address the province's current water overdraft. However, Almería will need to balance its planned initiatives against long-term estimates of projected agricultural and domestic development and the environmental consequences of adopting a desalination-supported water future.

Membrane scaling and flux decline during fertiliser-drawn forward osmosis desalination of brackish groundwater.

PubMed

Phuntsho, Sherub; Lotfi, Fezeh; Hong, Seungkwan; Shaffer, Devin L; Elimelech, Menachem; Shon, Ho Kyong

2014-06-15

Fertiliser-drawn forward osmosis (FDFO) desalination has been recently studied as one feasible application of forward osmosis (FO) for irrigation. In this study, the potential of membrane scaling in the FDFO process has been investigated during the desalination of brackish groundwater (BGW). While most fertilisers containing monovalent ions did not result in any scaling when used as an FO draw solution (DS), diammonium phosphate (DAP or (NH4)2HPO4) resulted in significant scaling, which contributed to severe flux decline. Membrane autopsy using scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD) analysis indicated that the reverse diffusion of DAP from the DS to the feed solution was primarily responsible for scale formation during the FDFO process. Physical cleaning of the membrane with deionised water at varying crossflow velocities was employed to evaluate the reversibility of membrane scaling and the extent of flux recovery. For the membrane scaled using DAP as DS, 80-90% of the original flux was recovered when the crossflow velocity for physical cleaning was the same as the crossflow velocity during FDFO desalination. However, when a higher crossflow velocity or Reynolds number was used, the flux was recovered almost completely, irrespective of the DS concentration used. This study underscores the importance of selecting a suitable fertiliser for FDFO desalination of brackish groundwater to avoid membrane scaling and severe flux decline. Copyright © 2014 Elsevier Ltd. All rights reserved.

Medium range forecasting of Hurricane Harvey flash flooding using ECMWF and social vulnerability data

NASA Astrophysics Data System (ADS)

Pillosu, F. M.; Jurlina, T.; Baugh, C.; Tsonevsky, I.; Hewson, T.; Prates, F.; Pappenberger, F.; Prudhomme, C.

2017-12-01

During hurricane Harvey the greater east Texas area was affected by extensive flash flooding. Their localised nature meant they were too small for conventional large scale flood forecasting systems to capture. We are testing the use of two real time forecast products from the European Centre for Medium-range Weather Forecasts (ECMWF) in combination with local vulnerability information to provide flash flood forecasting tools at the medium range (up to 7 days ahead). Meteorological forecasts are the total precipitation extreme forecast index (EFI), a measure of how the ensemble forecast probability distribution differs from the model-climate distribution for the chosen location, time of year and forecast lead time; and the shift of tails (SOT) which complements the EFI by quantifying how extreme an event could potentially be. Both products give the likelihood of flash flood generating precipitation. For hurricane Harvey, 3-day EFI and SOT products for the period 26th - 29th August 2017 were used, generated from the twice daily, 18 km, 51 ensemble member ECMWF Integrated Forecast System. After regridding to 1 km resolution the forecasts were combined with vulnerable area data to produce a flash flood hazard risk area. The vulnerability data were floodplains (EU Joint Research Centre), road networks (Texas Department of Transport) and urban areas (Census Bureau geographic database), together reflecting the susceptibility to flash floods from the landscape. The flash flood hazard risk area forecasts were verified using a traditional approach against observed National Weather Service flash flood reports, a total of 153 reported flash floods have been detected in that period. Forecasts performed best for SOT = 5 (hit ratio = 65%, false alarm ratio = 44%) and EFI = 0.7 (hit ratio = 74%, false alarm ratio = 45%) at 72 h lead time. By including the vulnerable areas data, our verification results improved by 5-15%, demonstrating the value of vulnerability information within natural hazard forecasts. This research shows that flash flooding from hurricane Harvey was predictable up to 4 days ahead and that filtering the forecasts to vulnerable areas provides a more focused guidance to civil protection agencies planning their emergency response.

Increasing Gas Hydrate Formation Temperature for Desalination of High Salinity Produced Water with Secondary Guests

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

Cha, Jong-Ho; Seol, Yongkoo

We suggest a new gas hydrate-based desalination process using water-immiscible hydrate formers; cyclopentane (CP) and cyclohexane (CH) as secondary hydrate guests to alleviate temperature requirements for hydrate formation. The hydrate formation reactions were carried out in an isobaric condition of 3.1 MPa to find the upper temperature limit of CO2 hydrate formation. Simulated produced water (8.95 wt % salinity) mixed with the hydrate formers shows an increased upper temperature limit from -2 °C for simple CO2 hydrate to 16 and 7 °C for double (CO2 + CP) and (CO2 + CH) hydrates, respectively. The resulting conversion rate to double hydratemore » turned out to be similar to that with simple CO2 hydrate at the upper temperature limit. Hydrate formation rates (Rf) for the double hydrates with CP and CH are shown to be 22 and 16 times higher, respectively, than that of the simple CO2 hydrate at the upper temperature limit. Such mild hydrate formation temperature and fast formation kinetics indicate increased energy efficiency of the double hydrate system for the desalination process. Dissociated water from the hydrates shows greater than 90% salt removal efficiency for the hydrates with the secondary guests, which is also improved from about 70% salt removal efficiency for the simple hydrates.« less

Ocular Screening System

NASA Technical Reports Server (NTRS)

1987-01-01

Used to detect eye problems in children through analysis of retinal reflexes, the system incorporates image processing techniques. VISISCREEN's photorefractor is basically a 35 millimeter camera with a telephoto lens and an electronic flash. By making a color photograph, the system can test the human eye for refractive error and obstruction in the cornea or lens. Ocular alignment problems are detected by imaging both eyes simultaneously. Electronic flash sends light into the eyes and the light is reflected from the retina back to the camera lens. Photorefractor analyzes the retinal reflexes generated by the subject's response to the flash and produces an image of the subject's eyes in which the pupils are variously colored. The nature of a defect, where such exists, is identifiable by atrained observer's visual examination.

Identified Natural Hazards May Cause Adverse Impact on Sustainability of Desalination Plants in Red Sea

NASA Astrophysics Data System (ADS)

Aburizaiza, O. S.; Zaigham, N. A.; Nayyar, Z. A.; Mahar, G. A.; Siddique, A.; Eusufi, S. N.

2011-12-01

The Red Sea and its surrounding countries have harsh arid climatic conditions where fast growth of the socio-economic activities and rapid change of lifestyle have caused tremendous stress on water to the level of acute crisis. To meet the water demands, the Red Sea countries have adopted seawater desalination giving priority against their land-based resources. Saudi Arabia is the largest desalinated-water producers in the Red Sea and has practically no adequate backup plan in case of sudden unforeseen emergency. Out of about 3.64 million m3/day, Saudi Arabia is alone being desalinated about 3.29 m3/day seawater from Red Sea and more projects are in progress. Present integrated research study has identified some of natural and anthropogenic hazards, which may be major threats to the quality of the seawater as well as to the desalination plants themselves. Results of present study reveal that the submarine complex morphologic features may cause the isolation of Red Sea from any of the open sea, the increase in the seismicity trends, the active volcanism causing unique longitudinal as well as transverse deformations of the axial trough particularly in the southern part of the Red Sea, the consistently generating enormous hot-brine tectonic-factory all along the deeper parts of the Red Sea rifting trough and other related issues. Considering the identified odd conditions, the total dependence on seawater desalination may not be worthwhile for sustainable water management strategy and consequent socio-economic developments in future. It is recommended that the priority should also be given mainly in three main disciplines to meet the future water challenges - one, developing reliable backup water management; second, alternate options for the supplementary resources of water; and third, the development and immediate implementation of the water-use conservation strategy plan.

A seawater desalination scheme for global hydrological models

NASA Astrophysics Data System (ADS)

Hanasaki, Naota; Yoshikawa, Sayaka; Kakinuma, Kaoru; Kanae, Shinjiro

2016-10-01

Seawater desalination is a practical technology for providing fresh water to coastal arid regions. Indeed, the use of desalination is rapidly increasing due to growing water demand in these areas and decreases in production costs due to technological advances. In this study, we developed a model to estimate the areas where seawater desalination is likely to be used as a major water source and the likely volume of production. The model was designed to be incorporated into global hydrological models (GHMs) that explicitly include human water usage. The model requires spatially detailed information on climate, income levels, and industrial and municipal water use, which represent standard input/output data in GHMs. The model was applied to a specific historical year (2005) and showed fairly good reproduction of the present geographical distribution and national production of desalinated water in the world. The model was applied globally to two periods in the future (2011-2040 and 2041-2070) under three distinct socioeconomic conditions, i.e., SSP (shared socioeconomic pathway) 1, SSP2, and SSP3. The results indicate that the usage of seawater desalination will have expanded considerably in geographical extent, and that production will have increased by 1.4-2.1-fold in 2011-2040 compared to the present (from 2.8 × 109 m3 yr-1 in 2005 to 4.0-6.0 × 109 m3 yr-1), and 6.7-17.3-fold in 2041-2070 (from 18.7 to 48.6 × 109 m3 yr-1). The estimated global costs for production for each period are USD 1.1-10.6 × 109 (0.002-0.019 % of the total global GDP), USD 1.6-22.8 × 109 (0.001-0.020 %), and USD 7.5-183.9 × 109 (0.002-0.100 %), respectively. The large spreads in these projections are primarily attributable to variations within the socioeconomic scenarios.

Investigation of Flash Fill{reg_sign} as a thermal backfill material

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

Ayers, P.H.; Charlton, C.B.; Frishette, C.W.

1995-09-01

Flash Fill{reg_sign} was created as a fast-setting, flowable backfill material made entirely from coal combustion by-products and water. Its quick-setting, self-leveling, self-compacting characteristics makes trench road repairs faster, easier, and more economical. Other uses include building foundations, fill around pipes, gas lines, and manholes, and replacement of weak subgrade beneath rooters. Flash Fill can be hand-excavated without the use of power assisted tools or machinery. To enhance thermal resistivity, the original Flash Fill mix was modified to include concrete sand. This resulted in a new Flash Fill, designated FSAND, with all of the aforementioned desirable characteristics of Flash Fill andmore » a thermal resistivity of approximately 50{degree} C-cm/watt. Thermal resistivity tests using conventional laboratory thermal probes, high-current thermal tests, and moisture migration tests have been performed to determine the properties of FSAND. As a result of these tests, FSAND has been approved for use as power cable thermal backfill on all AEP System distribution projects.« less

FLASH LIDAR Based Relative Navigation

NASA Technical Reports Server (NTRS)

Brazzel, Jack; Clark, Fred; Milenkovic, Zoran

2014-01-01

Relative navigation remains the most challenging part of spacecraft rendezvous and docking. In recent years, flash LIDARs, have been increasingly selected as the go-to sensors for proximity operations and docking. Flash LIDARS are generally lighter and require less power that scanning Lidars. Flash LIDARs do not have moving parts, and they are capable of tracking multiple targets as well as generating a 3D map of a given target. However, there are some significant drawbacks of Flash Lidars that must be resolved if their use is to be of long-term significance. Overcoming the challenges of Flash LIDARs for navigation-namely, low technology readiness level, lack of historical performance data, target identification, existence of false positives, and performance of vision processing algorithms as intermediaries between the raw sensor data and the Kalman filter-requires a world-class testing facility, such as the Lockheed Martin Space Operations Simulation Center (SOSC). Ground-based testing is a critical step for maturing the next-generation flash LIDAR-based spacecraft relative navigation. This paper will focus on the tests of an integrated relative navigation system conducted at the SOSC in January 2014. The intent of the tests was to characterize and then improve the performance of relative navigation, while addressing many of the flash LIDAR challenges mentioned above. A section on navigation performance and future recommendation completes the discussion.

Kappa Agonists as a Novel Therapy for Menopausal Hot Flashes

PubMed Central

Oakley, Amy E.; Steiner, Robert A.; Chavkin, Charles; Clifton, Donald K.; Ferrara, Laura K.; Reed, Susan D.

2015-01-01

Objective Postmenopausal hot flash etiology is poorly understood, making it difficult to develop and target ideal therapies. A network of hypothalamic estrogen-sensitive neurons producing Kisspeptin, Neurokinin B, and Dynorphin (KNDy neurons), located adjacent to the thermoregulatory center, regulate pulsatile secretion of GnRH and LH. Dynorphin may inhibit this system by binding kappa opioid receptors within the vicinity of KNDy neurons. We hypothesize that hot flashes are reduced by KNDy neuron manipulation. Methods A double-blind, cross-over, placebo-controlled pilot study evaluated the effect of a kappa agonist (KA).Hot flash frequency was the primary outcome. Twelve healthy postmenopausal women with moderate-severe hot flashes, ages 48-60 years, were randomized. Eight women with sufficient baseline hot flashes for statistical analysis completed all 3 interventions: placebo, standard Pentazocine/Naloxone (50/0.5 mg) or low-dose Pentazocine/Naloxone (25/0.25 mg). In an inpatient research setting, each participant received the 3 interventions, in randomized order, on 3 separate days. On each day, an intravenous catheter was inserted for luteinizing hormone (LH) blood sampling, and skin conductance and Holter monitors were placed. Subjective hot flash frequency and severity were recorded. Results Mean hot flash frequency 2-7 hours following therapy initiation was lower than that for placebo (KA standard-dose: 4.75 ± 0.67; KA low-dose: 4.50 ± 0.57; and placebo: 5.94 ± 0.78 hot flashes/5 hours; p =0.025). Hot flash intensity did not vary between interventions. LH pulsatility mirrored objective hot flashes in some, but not all women. Conclusions This pilot suggests that kappa agonists may affect menopausal vasomotor symptoms. PMID:25988798

Minimum energy requirements for desalination of brackish groundwater in the United States with comparison to international datasets

USGS Publications Warehouse

Ahdab, Yvana D.; Thiel, Gregory P.; Böhlke, John Karl; Stanton, Jennifer S.; Lienhard, John H.

2018-01-01

This paper uses chemical and physical data from a large 2017 U.S. Geological Surveygroundwater dataset with wells in the U.S. and three smaller international groundwater datasets with wells primarily in Australia and Spain to carry out a comprehensive investigation of brackish groundwater composition in relation to minimum desalinationenergy costs. First, we compute the site-specific least work required for groundwater desalination. Least work of separation represents a baseline for specific energy consumptionof desalination systems. We develop simplified equations based on the U.S. data for least work as a function of water recovery ratio and a proxy variable for composition, either total dissolved solids, specific conductance, molality or ionic strength. We show that the U.S. correlations for total dissolved solids and molality may be applied to the international datasets. We find that total molality can be used to calculate the least work of dilute solutions with very high accuracy. Then, we examine the effects of groundwater solute composition on minimum energy requirements, showing that separation requirements increase from calcium to sodium for cations and from sulfate to bicarbonate to chloride for anions, for any given TDS concentration. We study the geographic distribution of least work, total dissolved solids, and major ions concentration across the U.S. We determine areas with both low least work and high water stress in order to highlight regions holding potential for desalination to decrease the disparity between high water demand and low water supply. Finally, we discuss the implications of the USGS results on water resource planning, by comparing least work to the specific energy consumption of brackish water reverse osmosisplants and showing the scaling propensity of major electrolytes and silica in the U.S. groundwater samples.

THE DYNACELL AND FOCAL PLANE CONCEPTS OF PHOTOTROPIC SYSTEMS APPLICATION TO OPHTHALMIC NUCLEAR FLASH-PROTECTIVE DEVICES

DTIC Science & Technology

Two concepts of phototropic systems application are presented in this report. These concepts, when considered individually or in combination, make...possible the development of improved, directly or indirectly actuated, phototropic , ophthalmic, nuclear flash-protective devices. By the application...of a phototropic filter at the focal plane of an optical system, the attenuation of the phototropic response due to distance is minimized. Using a

The Behavior of Total Lightning Activity in Severe Florida Thunderstorms

NASA Technical Reports Server (NTRS)

Williams, Earle; Boldi, Bob; Matlin, Anne; Weber, Mark; Hodanish, Steve; Sharp, Dave; Goodman, Steve; Raghavan, Ravi; Buechler, Dennis

1998-01-01

The development of a new observational system called LISDAD (Lightning Imaging Sensor Demonstration and Display) has enabled a study of severe weather in central Florida. The total flash rates for storms verified to be severe are found to exceed 60 flashes/min, with some values reaching 500 flashes/min. Similar to earlier results for thunderstorm microbursts, the peak flash rate precedes the severe weather at the ground by 5-20 minutes. A distinguishing feature of severe storms is the presence of lightning "jumps"-abrupt increases in flash rate in advance of the maximum rate for the storm. ne systematic total lightning precursor to severe weather of all kinds-wind, hail, tornadoes-is interpreted in terms of the updraft that sows the seeds aloft for severe weather at the surface and simultaneously stimulates the ice microphysics that drives the lightning activity.

Nanophotonics-enabled solar membrane distillation for off-grid water purification.

PubMed

Dongare, Pratiksha D; Alabastri, Alessandro; Pedersen, Seth; Zodrow, Katherine R; Hogan, Nathaniel J; Neumann, Oara; Wu, Jinjian; Wang, Tianxiao; Deshmukh, Akshay; Elimelech, Menachem; Li, Qilin; Nordlander, Peter; Halas, Naomi J

2017-07-03

With more than a billion people lacking accessible drinking water, there is a critical need to convert nonpotable sources such as seawater to water suitable for human use. However, energy requirements of desalination plants account for half their operating costs, so alternative, lower energy approaches are equally critical. Membrane distillation (MD) has shown potential due to its low operating temperature and pressure requirements, but the requirement of heating the input water makes it energy intensive. Here, we demonstrate nanophotonics-enabled solar membrane distillation (NESMD), where highly localized photothermal heating induced by solar illumination alone drives the distillation process, entirely eliminating the requirement of heating the input water. Unlike MD, NESMD can be scaled to larger systems and shows increased efficiencies with decreased input flow velocities. Along with its increased efficiency at higher ambient temperatures, these properties all point to NESMD as a promising solution for household- or community-scale desalination.

The influences of separators on capacitive deionization systems in the cycle of adsorption and desorption.

PubMed

Yao, Qihan; Shi, Zhou; Liu, Qingqing; Gu, Zhengyang; Ning, Ruihuan

2018-02-01

This research focused on the influence of different separator compartments on the performance of capacitive deionization (CDI) cells in terms of brackish water treatment. For comparison, different separators including filter paper(FP), carbon nanotube (CNT), and stainless steel fiber (SSF) on deionization and desorption rate of salt were examined. The best performance was obtained when the CNT separator was packed, followed by SSF and FP. Reducing the cell voltage from 1.2 to 0.4 V decreased the salt removal and electrode regeneration rate of SSF-CDI. Electrochemical impedance spectrometry (EIS) analysis revealed that the resistance and specific capacitance of separator materials are essential to the desalination and desorption performance of CDI. The electric double layers (EDLs) accelerated the ion transfer in the flow chamber due to storing excess ions, therefore increasing the desalination and electrode regeneration rate.

A New Desalination Pump Helps Define the pH of Ocean Worlds

NASA Astrophysics Data System (ADS)

Levi, A.; Sasselov, D.

2018-04-01

We study ocean exoplanets, for which the global surface ocean is separated from the rocky interior by a high-pressure ice mantle. We describe a mechanism that can pump salts out of the ocean, resulting in oceans of very low salinity. Here we focus on the H2O–NaCl system, though we discuss the application of this pump to other salts as well. We find our ocean worlds to be acidic, with a pH in the range of 2–4. We discuss and compare between the conditions found within our studied oceans and the conditions in which polyextremophiles were discovered. This work focuses on exoplanets in the super-Earth mass range (∼2 M ⊕), with water composing at least a few percent of their mass. However, the principle of the desalination pump might extend beyond this mass range.

Nanophotonics-enabled solar membrane distillation for off-grid water purification

PubMed Central

Dongare, Pratiksha D.; Alabastri, Alessandro; Pedersen, Seth; Zodrow, Katherine R.; Hogan, Nathaniel J.; Neumann, Oara; Wu, Jinjian; Wang, Tianxiao; Deshmukh, Akshay; Elimelech, Menachem; Li, Qilin; Nordlander, Peter; Halas, Naomi J.

2017-01-01

With more than a billion people lacking accessible drinking water, there is a critical need to convert nonpotable sources such as seawater to water suitable for human use. However, energy requirements of desalination plants account for half their operating costs, so alternative, lower energy approaches are equally critical. Membrane distillation (MD) has shown potential due to its low operating temperature and pressure requirements, but the requirement of heating the input water makes it energy intensive. Here, we demonstrate nanophotonics-enabled solar membrane distillation (NESMD), where highly localized photothermal heating induced by solar illumination alone drives the distillation process, entirely eliminating the requirement of heating the input water. Unlike MD, NESMD can be scaled to larger systems and shows increased efficiencies with decreased input flow velocities. Along with its increased efficiency at higher ambient temperatures, these properties all point to NESMD as a promising solution for household- or community-scale desalination. PMID:28630307

Weak positive cloud-to-ground flashes in Northeastern Colorado

NASA Technical Reports Server (NTRS)

Lopez, Raul E.; Maier, Michael W.; Garcia-Miguel, Juan A.; Holle, Ronald L.

1991-01-01

The frequency distributions of the peak magnetic field associated with the first detected return stroke of positive and negative cloud-to-ground (CG) flashes were studied using lightning data from northeastern Colorado. These data were obtained during 1985 with a medium-to-high gain network of three direction finders (DF's). The median signal strength of positive flashes was almost two times that of the negatives for flashes within 300 km of the DF's, which have an inherent detection-threshold bias that tends to discriminate against weak signals. This bias increases with range, and affects the detection of positive and negative flashes in different ways, because of the differing character of their distributions. Positive flashes appear to have a large percentage of signals clustered around very weak values that are lost to the medium-to-high gain Colorado Detection System very quickly with increasing range. The resulting median for positive signals could thus appear to be much larger than the median for negative signals, which are more clustered around intermediate values. When only flashes very close to the DF's are considered, however, the two distributions have almost identical medians. The large percentage of weak positive signals detected close to the DF's has not been explored previously. They have been suggested to come from intracloud discharges and thus are improperly classified as CG flashes. Evidence in hand, points to their being real positive, albeit weak CG flashes. Whether or not they are real positive ground flashes, it is important to be aware of their presence in data from magnetic DF networks.

High Resolution Flash Flood Forecasting Using a Wireless Sensor Network in the Dallas-Fort Worth Metroplex

NASA Astrophysics Data System (ADS)

Bartos, M. D.; Kerkez, B.; Noh, S.; Seo, D. J.

2017-12-01

In this study, we develop and evaluate a high resolution urban flash flood monitoring system using a wireless sensor network (WSN), a real-time rainfall-runoff model, and spatially-explicit radar rainfall predictions. Flooding is the leading cause of natural disaster fatalities in the US, with flash flooding in particular responsible for a majority of flooding deaths. While many riverine flood models have been operationalized into early warning systems, there is currently no model that is capable of reliably predicting flash floods in urban areas. Urban flash floods are particularly difficult to model due to a lack of rainfall and runoff data at appropriate scales. To address this problem, we develop a wide-area flood-monitoring wireless sensor network for the Dallas-Fort Worth metroplex, and use this network to characterize rainfall-runoff response over multiple heterogeneous catchments. First, we deploy a network of 22 wireless sensor nodes to collect real-time stream stage measurements over catchments ranging from 2-80 km2 in size. Next, we characterize the rainfall-runoff response of each catchment by combining stream stage data with gage and radar-based precipitation measurements. Finally, we demonstrate the potential for real-time flash flood prediction by joining the derived rainfall-runoff models with real-time radar rainfall predictions. We find that runoff response is highly heterogeneous among catchments, with large variabilities in runoff response detected even among nearby gages. However, when spatially-explicit rainfall fields are included, spatial variability in runoff response is largely captured. This result highlights the importance of increased spatial coverage for flash flood prediction.

Multi-objective Optimization of Solar-driven Hollow-fiber Membrane Distillation Systems

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

Nenoff, Tina M.; Moore, Sarah E.; Mirchandani, Sera

Securing additional water sources remains a primary concern for arid regions in both the developed and developing world. Climate change is causing fluctuations in the frequency and duration of precipitation, which can be can be seen as prolonged droughts in some arid areas. Droughts decrease the reliability of surface water supplies, which forces communities to find alternate primary water sources. In many cases, ground water can supplement the use of surface supplies during periods of drought, reducing the need for above-ground storage without sacrificing reliability objectives. Unfortunately, accessible ground waters are often brackish, requiring desalination prior to use, and underdevelopedmore » infrastructure and inconsistent electrical grid access can create obstacles to groundwater desalination in developing regions. The objectives of the proposed project are to (i) mathematically simulate the operation of hollow fiber membrane distillation systems and (ii) optimize system design for off-grid treatment of brackish water. It is anticipated that methods developed here can be used to supply potable water at many off-grid locations in semi-arid regions including parts of the Navajo Reservation. This research is a collaborative project between Sandia and the University of Arizona.« less

I-process Nucleosynthesis and Mass Retention Efficiency in He-shell Flash Evolution of Rapidly Accreting White Dwarfs

NASA Astrophysics Data System (ADS)

Denissenkov, Pavel A.; Herwig, Falk; Battino, Umberto; Ritter, Christian; Pignatari, Marco; Jones, Samuel; Paxton, Bill

2017-01-01

Based on stellar evolution simulations, we demonstrate that rapidly accreting white dwarfs (WDs) in close binary systems are an astrophysical site for the intermediate neutron-capture process. During recurrent and very strong He-shell flashes in the stable H-burning accretion regime H-rich material enters the He-shell flash convection zone. {}12{{C}}(p,γ ){}13{{N}} reactions release enough energy to potentially impact convection, and I process is activated through the {}13{{C}}{(α ,{{n}})}16{{O}} reaction. The H-ingestion flash may not cause a split of the convection zone as it was seen in simulations of He-shell flashes in post-AGB and low-Z asymptotic giant branch (AGB) stars. We estimate that for the production of first-peak heavy elements this site can be of similar importance for galactic chemical evolution as the s-process production by low-mass AGB stars. The He-shell flashes result in the expansion and, ultimately, ejection of the accreted and then I-process enriched material, via super-Eddington-luminosity winds or Roche-lobe overflow. The WD models do not retain any significant amount of the accreted mass, with a He retention efficiency of ≲ 10 % depending on mass and convective boundary mixing assumptions. This makes the evolutionary path of such systems to supernova Ia explosion highly unlikely.

A Brief 30-Year Review: Research Highlights from Lightning Mapping Systems 1970-2000

NASA Astrophysics Data System (ADS)

MacGorman, D. R.

2016-12-01

Modern lightning mapping began in the 1970s, the decade in which VHF mapping systems, acoustic mapping systems, and ground strike locating systems were introduced. Adding GPS synchronization of VHF systems in the late 1990s enabled real-time VHF mapping systems to be deployed more extensively. Data these systems provided by 2000 revolutionized our understanding of how storms produce lightning. Among key results: Electrostatics, not electrodynamics, governs where lightning is initiated and where it propagates, contrary to early expectations. Lightning is initiated in a region of large electric field magnitude, typically between a positive charge region and a negative charge region. The geometry of a storm's charge regions governs the spatial extent of each end of the flash. The flash initially propagates bidirectionally toward the two charge regions that initiated it, and once it reaches the charge regions and maximizes the ambient potential difference spanned by the flash structure, it extends through each charge region's ambient electric potential well until the total electric field magnitude at the ends of the flash drops below the threshold for continued propagation. The typical charge distribution producing a cloud-to-ground flash is a region of charge of the polarity being lowered to ground, above a lesser amount of charge of the opposite polarity; the lower region has too little charge to capture the downward propagating channel. Contrary to previous understanding, naturally occurring cloud-to-ground lightning often lowers positive charge to ground, instead of the usual negative charge, in several situations, including winter storms, stratiform precipitation regions, some severe storms, and storms on the High Plains of the United States. The reason cloud-to-ground activity in some storms is dominated by flashes that lower positive charge to ground is that the polarity of the main charge regions in those storms is inverted from the usual polarity, with the main mid-level charge being positive and the main upper-level charge being negative. This strongly implies that the dominant non-inductive electrification mechanism is inverted in those storms, probably because the liquid water content in the mixed phase region is larger than in most storms.

Multi-stage flash degaser

DOEpatents

Rapier, Pascal M.

1982-01-01

A multi-stage flash degaser (18) is incorporated in an energy conversion system (10) having a direct-contact, binary-fluid heat exchanger to remove essentially all of the noncondensable gases from geothermal brine ahead of the direct-contact binary-fluid heat exchanger (22) in order that the heat exchanger (22) and a turbine (48) and condenser (32) of the system (10) can operate at optimal efficiency.

Nanotechnology, resources, and pollution control

NASA Astrophysics Data System (ADS)

Gillett, Stephen L.

1996-09-01

The separation of different kinds of atoms or molecules from each other is a fundamental technological problem. Current techniques of resource extraction, which use the ancient paradigm of the differential partitioning of elements into coexisting phases, are simple but extremely wasteful and require feedstocks (`ores') that are already anomalously enriched. This is impractical for pollution control and desalination, which require extraction of low concentrations; instead, atomistic separation, typically by differential motion through semipermeable membranes, is used. The present application of such membranes is seriously limited, however, mostly because of limitations in their fabrication by conventional bulk techniques. The capabilities of biological systems, such as vertebrate kidneys, are vastly better, largely because they are intrinsically structured at a molecular scale. Nanofabrication of semipermeable membranes promises capabilities on the order of those of biological systems, and this in turn could provide much financial incentive for the development of molecular assemblers, as well established markets exist already. Continued incentives would exist, moreover, as markets expanded with decreasing costs, leading to such further applications as remediation of polluted sites, cheap desalination, and resource extraction from very low-grade sources.

Mutational analysis of FLASH and PTPN13 genes in colorectal carcinomas.

PubMed

Jeong, Eun Goo; Lee, Sung Hak; Yoo, Nam Jin; Lee, Sug Hyung

2008-01-01

The Fas-Fas ligand system is considered a major pathway for induction of apoptosis in cells and tissues. FLASH was identified as a pro-apoptotic protein that transmits apoptosis signal during Fas-mediated apoptosis. PTPN13 interacts with Fas and functions as both suppressor and inducer of Fas-mediated apoptosis. There are polyadenine tracts in both FLASH (A8 and A9 in exon 8) and PTPN13 (A8 in exon 7) genes that could be frameshift mutation targets in colorectal carcinomas. Because genes encoding proteins in Fas-mediated apoptosis frequently harbor somatic mutations in cancers, we explored the possibility as to whether mutations of FLASH and PTPN13 are a feature of colorectal carcinomas. We analysed human FLASH in exon 8 and PTPN13 in exon 7 for the detection of somatic mutations in 103 colorectal carcinomas by a polymerase chain reaction (PCR)- based single-strand conformation polymorphism (SSCP). We detected two mutations in FLASH gene, but none in PTPN13 gene. However, the two mutations were not frameshift (deletion or insertion) mutations in the polyadenine tracts of FLASH. The two mutations consisted of a deletion mutation (c.3734-3737delAGAA) and a missense mutation (c.3703A>C). These data indicate that frameshift mutation in the polyadenine tracts in both FLASH and PTPN13 genes is rare in colorectal carcinomas. Also, the data suggest that both FLASH and PTPN13 mutations in the polyadenine tracts may not have a crucial role in the pathogenesis of colorectal carcinomas.

TRMM-Based Lightning Climatology

NASA Technical Reports Server (NTRS)

Cecil, Daniel J.; Buechler, Dennis E.; Blakeslee, Richard J.

2011-01-01

Gridded climatologies of total lightning flash rates seen by the spaceborne Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) have been updated. OTD collected data from May 1995 to March 2000. LIS data (equatorward of about 38 deg) has been added for 1998-2010. Flash counts from each instrument are scaled by the best available estimates of detection efficiency. The long LIS record makes the merged climatology most robust in the tropics and subtropics, while the high latitude data is entirely from OTD. The mean global flash rate from the merged climatology is 46 flashes per second. The peak annual flash rate at 0.5 deg scale is 160 fl/square km/yr in eastern Congo. The peak monthly average flash rate at 2.5 scale is 18 fl/square km/mo, from early April to early May in the Brahmaputra Valley of far eastern India. Lightning decreases in this region during the monsoon season, but increases further north and west. A monthly average peak from early August to early September in northern Pakistan also exceeds any monthly averages from Africa, despite central Africa having the greatest yearly average. Most continental regions away from the equator have an annual cycle with lightning flash rates peaking in late spring or summer. The main exceptions are India and southeast Asia, with springtime peaks in April and May. For landmasses near the equator, flash rates peak near the equinoxes. For many oceanic regions, the peak flash rates occur in autumn. This is particularly noticeable for the Mediterranean and North Atlantic. Landmasses have a strong diurnal cycle of lightning, with flash rates generally peaking between 3-5 pm local solar time. The central United States flash rates peak later, in late evening or early night. Flash rates peak after midnight in northern Argentina. These regions are known for large, intense, long-lived mesoscale convective systems.

Severe storm electricity

NASA Technical Reports Server (NTRS)

Rust, W. D.; Macgorman, D. R.; Taylor, W.; Arnold, R. T.

1984-01-01

Severe storms and lightning were measured with a NASA U2 and ground based facilities, both fixed base and mobile. Aspects of this program are reported. The following results are presented: (1) ground truth measurements of lightning for comparison with those obtained by the U2. These measurements include flash type identification, electric field changes, optical waveforms, and ground strike location; (2) simultaneous extremely low frequency (ELF) waveforms for cloud to ground (CG) flashes; (3) the CG strike location system (LLP) using a combination of mobile laboratory and television video data are assessed; (4) continued development of analog-to-digital conversion techniques for processing lightning data from the U2, mobile laboratory, and NSSL sensors; (5) completion of an all azimuth TV system for CG ground truth; (6) a preliminary analysis of both IC and CG lightning in a mesocyclone; and (7) the finding of a bimodal peak in altitude lightning activity in some storms in the Great Plains and on the east coast. In the forms on the Great Plains, there was a distinct class of flash what forms the upper mode of the distribution. These flashes are smaller horizontal extent, but occur more frequently than flashes in the lower mode of the distribution.

Flash floods warning technique based on wireless communication networks data

NASA Astrophysics Data System (ADS)

David, Noam; Alpert, Pinhas; Messer, Hagit

2010-05-01

Flash floods can occur throughout or subsequent to rainfall events, particularly in cases where the precipitation is of high-intensity. Unfortunately, each year these floods cause severe property damage and heavy casualties. At present, there are no sufficient real time flash flood warning facilities found to cope with this phenomenon. Here we show the tremendous potential of flash floods advanced warning based on precipitation measurements of commercial microwave links. As was recently shown, wireless communication networks supply high resolution precipitation measurements at ground level while often being situated in flood prone areas, covering large parts of these hazardous regions. We present the flash flood warning potential of the wireless communication system for two different cases when floods occurred at the Judean desert and at the northern Negev in Israel. In both cases, an advanced warning regarding the hazard could have been announced based on this system. • This research was supported by THE ISRAEL SCIENCE FOUNDATION (grant No. 173/08). This work was also supported by a grant from the Yeshaya Horowitz Association, Jerusalem. Additional support was given by the PROCEMA-BMBF project and by the GLOWA-JR BMBF project.

Quantitative comparison of the application accuracy between NDI and IGT tracking systems

NASA Astrophysics Data System (ADS)

Li, Qinghang; Zamorano, Lucia J.; Jiang, Charlie Z. W.; Gong, JianXing; Diaz, Fernando

1999-07-01

The application accuracy is a crucial factor for the stereotactic surgical localization system in which space digitization system is one of the most important part of equipment. In this study we compared the application accuracy of using the OPTOTRAK space digitization system (OPTOTRAK 3020, Northern Digital, Waterloo, CAN) and FlashPoint Model 3000 and 5000 3-D digitizer systems (FlashPoint Model 3000 and 5000, Image Guided Surgery Technology Inc., Boulder, CO 80301, USA) for interactive localization of intracranial lesions. A phantom was mounted with the implantable frameless marker system (Fischer- Leibinger, Freiburg, Germany) which randomly distributed markers on the surface of the phantom. The target point was digitized and the coordinates were recorded and compared with reference points. The differences from the reference points were used as the deviation from the `true point'. The mean square root was calculated to show the sum of vectors. A paired t-test was used to analyze results. The results of the phantom showed that the mean square roots were 0.76 +/- 0.54 mm for the OPTOTRAK system and 1.23 +/- 0.53 mm for FlashPoint Model 3000 3-D digitizer system and 1.00 +/- 0.42 mm for FlashPoint Model 3000 3-D digitizer system in the 1 mm sections of CT scan. This preliminary results showed that there is no significant difference between two tracking systems. Both of them can be used for image guided surgery procedure.

Adaptive aperture for Geiger mode avalanche photodiode flash ladar systems.

PubMed

Wang, Liang; Han, Shaokun; Xia, Wenze; Lei, Jieyu

2018-02-01

Although the Geiger-mode avalanche photodiode (GM-APD) flash ladar system offers the advantages of high sensitivity and simple construction, its detection performance is influenced not only by the incoming signal-to-noise ratio but also by the absolute number of noise photons. In this paper, we deduce a hyperbolic approximation to estimate the noise-photon number from the false-firing percentage in a GM-APD flash ladar system under dark conditions. By using this hyperbolic approximation function, we introduce a method to adapt the aperture to reduce the number of incoming background-noise photons. Finally, the simulation results show that the adaptive-aperture method decreases the false probability in all cases, increases the detection probability provided that the signal exceeds the noise, and decreases the average ranging error per frame.

Adaptive aperture for Geiger mode avalanche photodiode flash ladar systems

NASA Astrophysics Data System (ADS)

Wang, Liang; Han, Shaokun; Xia, Wenze; Lei, Jieyu

2018-02-01

Although the Geiger-mode avalanche photodiode (GM-APD) flash ladar system offers the advantages of high sensitivity and simple construction, its detection performance is influenced not only by the incoming signal-to-noise ratio but also by the absolute number of noise photons. In this paper, we deduce a hyperbolic approximation to estimate the noise-photon number from the false-firing percentage in a GM-APD flash ladar system under dark conditions. By using this hyperbolic approximation function, we introduce a method to adapt the aperture to reduce the number of incoming background-noise photons. Finally, the simulation results show that the adaptive-aperture method decreases the false probability in all cases, increases the detection probability provided that the signal exceeds the noise, and decreases the average ranging error per frame.

Investigation of spray characteristics for flashing injection of fuels containing dissolved air and superheated fuels

NASA Technical Reports Server (NTRS)

Solomon, A. S. P.; Chen, L. D.; Faeth, G. M.

1982-01-01

The flow, atomization and spreading of flashing injector flowing liquids containing dissolved gases (jet/air) as well as superheated liquids (Freon II) were considered. The use of a two stage expansion process separated by an expansion chamber, ws found to be beneficial for flashing injection particularly for dissolved gas systems. Both locally homogeneous and separated flow models provided good predictions of injector flow properties. Conventional correlations for drop sizes from pressure atomized and airblast injectors were successfully modified, using the separated flow model to prescribe injector exit conditions, to correlate drop size measurements. Additional experimental results are provided for spray angle and combustion properties of sprays from flashing injectors.

A Fault-Tolerant Radiation-Robust Mass Storage Concept for Highly Scaled Flash Memory

NASA Astrophysics Data System (ADS)

Fuchs, Cristian M.; Trinitis, Carsten; Appel, Nicolas; Langer, Martin

2015-09-01

Future spacemissions will require vast amounts of data to be stored and processed aboard spacecraft. While satisfying operational mission requirements, storage systems must guarantee data integrity and recover damaged data throughout the mission. NAND-flash memories have become popular for space-borne high performance mass memory scenarios, though future storage concepts will rely upon highly scaled flash or other memory technologies. With modern flash memory, single bit erasure coding and RAID based concepts are insufficient. Thus, a fully run-time configurable, high performance, dependable storage concept, requiring a minimal set of logic or software. The solution is based on composite erasure coding and can be adjusted for altered mission duration or changing environmental conditions.

Modeling heat and moisture transport in firefighter protective clothing during flash fire exposure

NASA Astrophysics Data System (ADS)

Chitrphiromsri, Patirop; Kuznetsov, Andrey V.

2005-01-01

In this paper, a model of heat and moisture transport in firefighter protective clothing during a flash fire exposure is presented. The aim of this study is to investigate the effect of coupled heat and moisture transport on the protective performance of the garment. Computational results show the distribution of temperature and moisture content in the fabric during the exposure to the flash fire as well as during the cool-down period. Moreover, the duration of the exposure during which the garment protects the firefighter from getting second and third degree burns from the flash fire exposure is numerically predicted. A complete model for the fire-fabric-air gap-skin system is presented.

Energy portfolio of Iran: A case study of solar desalination

NASA Astrophysics Data System (ADS)

Besharati, Adib

Energy plays a very important role in the economic development of a country such as Iran where industrial progress and higher living standards increase demand for energy. Iran is one of the countries in the world that simultaneously produces and consumes large amounts of energy. Because of its geographic latitude and weather conditions, Iran has the potential to develop and use of both fossil and renewable energy sources. In South Iran, there are huge oil and gas resources, and at the same time high potential of solar radiation. However, at the present large-scale utilization, solar energy is prohibitively expensive for Iran. Therefore, this study investigates an economical way to utilize solar energy in a meaningful way for Iran. One of the possible uses of solar energy that is both economical and technically feasible is desalination of water using solar energy. People in South Iran live in different areas with relatively low population density. One of the critical problems in those areas is a lack of clean drinking water. As a result, there is an urgent need to investigate ways to produce clean water from the saltwater. Therefore, the present study conducts a case study of solar desalination in south Iran using solar. Different desalination methods, such as humidification dehumidification by using a solar collector, and reverse osmosis, are discussed. In the case study, a prototype desalination plant was considered and both technical and economic aspects of the plant were investigated in details. The results showed higher productivity of drinking water in reverse osmosis method for south Iran.

Unlocking High-Salinity Desalination with Cascading Osmotically Mediated Reverse Osmosis: Energy and Operating Pressure Analysis.

PubMed

Chen, Xi; Yip, Ngai Yin

2018-02-20

Current practice of using thermally driven methods to treat hypersaline brines is highly energy-intensive and costly. While conventional reverse osmosis (RO) is the most efficient desalination technique, it is confined to purifying seawater and lower salinity sources. Hydraulic pressure restrictions and elevated energy demand render RO unsuitable for high-salinity streams. Here, we propose an innovative cascading osmotically mediated reverse osmosis (COMRO) technology to overcome the limitations of conventional RO. The innovation utilizes the novel design of bilateral countercurrent reverse osmosis stages to depress the hydraulic pressure needed by lessening the osmotic pressure difference across the membrane, and simultaneously achieve energy savings. Instead of the 137 bar required by conventional RO to desalinate 70 000 ppm TDS hypersaline feed, the highest operating pressure in COMRO is only 68.3 bar (-50%). Furthermore, up to ≈17% energy saving is attained by COMRO (3.16 kWh/m 3 , compared to 3.79 kWh/m 3 with conventional RO). When COMRO is employed to boost the recovery of seawater desalination to 70% from the typical 35-50%, energy savings of up to ≈33% is achieved (2.11 kWh/m 3 , compared to 3.16 kWh/m 3 with conventional RO). Again, COMRO can operate at a moderate hydraulic pressure of 80 bar (25% lower than 113 bar of conventional RO). This study highlights the encouraging potential of energy-efficient COMRO to access unprecedented high recovery rates and treat hypersaline brines at moderate hydraulic pressures, thus extending the capabilities of membrane-based technologies for high-salinity desalination.

Desalination and hydrogen, chlorine, and sodium hydroxide production via electrophoretic ion exchange and precipitation.

PubMed

Shkolnikov, Viktor; Bahga, Supreet S; Santiago, Juan G

2012-08-28

We demonstrate and analyze a novel desalination method which works by electrophoretically replacing sodium and chloride in feed salt water with a pair of ions, calcium and carbonate, that react and precipitate out. The resulting calcium carbonate precipitate is benign to health, and can be filtered or settled out, yielding low ionic strength product water. The ion exchange and precipitation employs self-sharpening interfaces induced by movement of multiple ions in an electric field to prevent contamination of the product water. Simultaneously, the electrolysis associated with the electromigration produces hydrogen gas, chlorine gas, and sodium hydroxide. We conducted an experimental study of this method's basic efficacy to desalinate salt water from 100 to 600 mol m(-3) sodium chloride. We also present physicochemical models of the process, and analyze replacement reagents consumption, permeate recovery ratio, and energy consumption. We hypothesize that the precipitate can be recycled back to replacement reagents using the well-known, commercially implemented Solvay process. We show that the method's permeate recovery ratio is 58% to 46%, which is on par with that of reverse osmosis. We show that the method's energy consumption requirement over and above that necessary to generate electrolysis is 3 to 10 W h l(-1), which is on par with the energy consumed by state-of-the-art desalination methods. Furthermore, the method operates at ambient temperature and pressure, and uses no specialized membranes. The process may be feasible as a part of a desalination-co-generation facility: generating fresh water, hydrogen and chlorine gas, and sodium hydroxide.

Temperature and Pressure Effects of Desalination Using a MFI-Type Zeolite Membrane

PubMed Central

Zhu, Bo; Kim, Jun Hyun; Na, Yong-Han; Moon, Il-Shik; Connor, Greg; Maeda, Shuichi; Morris, Gayle; Gray, Stephen; Duke, Mikel

2013-01-01

Zeolites are potentially a robust desalination alternative, as they are chemically stable and possess the essential properties needed to reject ions. Zeolite membranes could desalinate “challenging” waters, such as saline secondary effluent, without any substantial pre-treatment, due to the robust mechanical properties of ceramic membranes. A novel MFI-type zeolite membrane was developed on a tubular α-Al2O3 substrate by a combined rubbing and secondary hydrothermal growth method. The prepared membrane was characterised by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and single gas (He or N2) permeation and underwent desalination tests with NaCl solutions under different pressures (0.7 MPa and 7 MPa). The results showed that higher pressure resulted in higher Na+ rejection and permeate flux. The zeolite membrane achieved a good rejection of Na+ (~82%) for a NaCl feed solution with a TDS (total dissolved solids) of 3000 mg·L−1 at an applied pressure of 7 MPa and 21 °C. To explore the opportunity for high salinity and high temperature desalination, this membrane was also tested with high concentration NaCl solutions (up to TDS 90,000 mg·L−1) and at 90 °C. This is the first known work at such high salinities of NaCl. It was found that increasing the salinity of the feed solution decreased both Na+ rejection and flux. An increase in testing temperature resulted in an increase in permeate flux, but a decrease in ion rejection. PMID:24956943

Flash-lag effect: complicating motion extrapolation of the moving reference-stimulus paradoxically augments the effect.

PubMed

Bachmann, Talis; Murd, Carolina; Põder, Endel

2012-09-01

One fundamental property of the perceptual and cognitive systems is their capacity for prediction in the dynamic environment; the flash-lag effect has been considered as a particularly suggestive example of this capacity (Nijhawan in nature 370:256-257, 1994, Behav brain sci 31:179-239, 2008). Thus, because of involvement of the mechanisms of extrapolation and visual prediction, the moving object is perceived ahead of the simultaneously flashed static object objectively aligned with the moving one. In the present study we introduce a new method and report experimental results inconsistent with at least some versions of the prediction/extrapolation theory. We show that a stimulus moving in the opposite direction to the reference stimulus by approaching it before the flash does not diminish the flash-lag effect, but rather augments it. In addition, alternative theories (in)capable of explaining this paradoxical result are discussed.

Impact of spacer thickness on biofouling in forward osmosis.

PubMed

Valladares Linares, R; Bucs, Sz S; Li, Z; AbuGhdeeb, M; Amy, G; Vrouwenvelder, J S

2014-06-15

Forward osmosis (FO) indirect desalination systems integrate wastewater recovery with seawater desalination. Niche applications for FO systems have been reported recently, due to the demonstrated advantages compared to conventional high-pressure membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Among them, wastewater recovery has been identified to be particularly suitable for practical applications. However, biofouling in FO membranes has rarely been studied in applications involving wastewater effluents. Feed spacers separating the membrane sheets in cross-flow systems play an important role in biofilm formation. The objective of this study was to determine the influence of feed spacer thickness (28, 31 and 46 mil) on biofouling development and membrane performance in a FO system, using identical cross-flow cells in parallel studies. Flux development, biomass accumulation, fouling localization and composition were determined and analyzed. For all spacer thicknesses, operated at the same feed flow and the same run time, the same amount of biomass was found, while the flux reduction decreased with thicker spacers. These observations are in good agreement with biofouling studies for RO systems, considering the key differences between FO and RO. Our findings contradict previous cross-flow studies on particulate/colloidal fouling, where higher cross-flow velocities improved system performance. Thicker spacers reduced the impact of biofouling on FO membrane flux. Copyright © 2014 Elsevier Ltd. All rights reserved.

Subsurface intake systems: Green choice for improving feed water quality at SWRO desalination plants, Jeddah, Saudi Arabia.

PubMed

Dehwah, Abdullah H A; Missimer, Thomas M

2016-01-01

An investigation of three seawater reverse osmosis facilities located along the shoreline of the Red Sea of Saudi Arabia that use well intake systems showed that the pumping-induced flow of raw seawater through a coastal aquifer significantly improves feed water quality. A comparison between the surface seawater and the discharge from the wells shows that turbidity, algae, bacteria, total organic carbon, most fractions of natural organic matter (NOM), and particulate and colloidal transparent exopolymer particles (TEP) have significant reductions in concentration. Nearly all of the algae, up to 99% of the bacteria, between 84 and 100% of the biopolymer fraction of NOM, and a high percentage of the TEP were removed during transport. The data suggest that the flowpath length and hydraulic retention time in the aquifer play the most important roles in removal of the organic matter. Since the collective concentrations of bacteria, biopolymers, and TEP in the intake seawater play important roles in the biofouling of SWRO membranes, the observed reductions suggest that the desalination facilities that use well intakes systems will have a potentially lower fouling rate compared to open-ocean intake systems. Furthermore, well intake system intakes also reduce the need for chemical usage during complex pretreatment systems required for operation of SWRO facilities using open-ocean intakes and reduce environmental impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Graphene membranes with nanoslits for seawater desalination via forward osmosis.

PubMed

Dahanayaka, Madhavi; Liu, Bo; Hu, Zhongqiao; Pei, Qing-Xiang; Chen, Zhong; Law, Adrian Wing-Keung; Zhou, Kun

2017-11-22

Stacked graphene (GE) membranes with cascading nanoslits can be synthesized economically compared to monolayer nanoporous GE membranes, and have potential for molecular separation. This study focuses on investigating the seawater desalination performance of these stacked GE layers as forward osmosis (FO) membranes by using molecular dynamics simulations. The FO performance is evaluated in terms of water flux and salt rejection and is explained by analysing the water density distribution and radial distribution function. The water flow displays an Arrhenius type relation with temperature and the activation energy for the stacked GE membrane is estimated to be 8.02 kJ mol -1 , a value much lower than that of commercially available FO membranes. The study reveals that the membrane characteristics including the pore width, offset, interlayer separation distance and number of layers have significant effects on the desalination performance. Unlike monolayer nanoporous GE membranes, at an optimum layer separation distance, the stacked GE membranes with large pore widths and completely misaligned pore configuration can retain complete ion rejection and maintain a high water flux. Findings from the present study are helpful in developing GE-based membranes for seawater desalination via FO.

Carbon electrode for desalination purpose in capacitive deionization

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

Endarko,, E-mail: endarko@physics.its.ac.id; Fadilah, Nurul; Anggoro, Diky

Carbon electrodes for desalination purpose have been successfully synthesized using activated carbon powder (BET surface area=700 – 1400 m{sup 2}/g), carbon black and polyvinyl alcohol (PVA) binder by cross-linking method with glutaric acid (GA) at 120 °C. The electrochemical properties of the carbon electrodes were analyzed using electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) whilst the physical properties were observed with scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). In order to assess the desalting performance, salt removal experiments were performed by constructing a capacitive deionization unit cell with five pairs of carbon electrodes. For each pair consistedmore » of two parallel carbon electrodes separated by a spacer. Desalination and regeneration processes were also observed in the salt-removal experiments. The salt-removal experiments were carried out in single-pass mode using a solution with 0.1 M NaCl at a flow rate of 10 mL/min. A voltage of 3 V was applied to the cell for 60 minutes for both processes in desalination and regeneration. The result showed that the percentage value of the salt-removal was achieved at 20%.« less

Biodesalination-On harnessing the potential of nature's desalination processes.

PubMed

Taheri, Reza; Razmjou, Amir; Szekely, Gyorgy; Hou, Jingwei; Ghezelbash, Gholam Reza

2016-07-08

Water scarcity is now one of the major global crises, which has affected many aspects of human health, industrial development and ecosystem stability. To overcome this issue, water desalination has been employed. It is a process to remove salt and other minerals from saline water, and it covers a variety of approaches from traditional distillation to the well-established reverse osmosis. Although current water desalination methods can effectively provide fresh water, they are becoming increasingly controversial due to their adverse environmental impacts including high energy intensity and highly concentrated brine waste. For millions of years, microorganisms, the masters of adaptation, have survived on Earth without the excessive use of energy and resources or compromising their ambient environment. This has encouraged scientists to study the possibility of using biological processes for seawater desalination and the field has been exponentially growing ever since. Here, the term biodesalination is offered to cover all of the techniques which have their roots in biology for producing fresh water from saline solution. In addition to reviewing and categorizing biodesalination processes for the first time, this review also reveals unexplored research areas in biodesalination having potential to be used in water treatment.

47 CFR 213.6 - Criteria.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Criteria. 213.6 Section 213.6 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL GOVERNMENT AND PUBLIC CORRESPONDENCE TELECOMMUNICATIONS PRECEDENCE SYSTEM § 213.6 Criteria. (a) Flash, Flash Emergency. (1) This is the...

47 CFR 213.6 - Criteria.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Criteria. 213.6 Section 213.6 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL GOVERNMENT AND PUBLIC CORRESPONDENCE TELECOMMUNICATIONS PRECEDENCE SYSTEM § 213.6 Criteria. (a) Flash, Flash Emergency. (1) This is the...

47 CFR 213.6 - Criteria.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Criteria. 213.6 Section 213.6 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL GOVERNMENT AND PUBLIC CORRESPONDENCE TELECOMMUNICATIONS PRECEDENCE SYSTEM § 213.6 Criteria. (a) Flash, Flash Emergency. (1) This is the...

47 CFR 213.6 - Criteria.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Criteria. 213.6 Section 213.6 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL GOVERNMENT AND PUBLIC CORRESPONDENCE TELECOMMUNICATIONS PRECEDENCE SYSTEM § 213.6 Criteria. (a) Flash, Flash Emergency. (1) This is the...

47 CFR 213.6 - Criteria.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Criteria. 213.6 Section 213.6 Telecommunication OFFICE OF SCIENCE AND TECHNOLOGY POLICY AND NATIONAL SECURITY COUNCIL GOVERNMENT AND PUBLIC CORRESPONDENCE TELECOMMUNICATIONS PRECEDENCE SYSTEM § 213.6 Criteria. (a) Flash, Flash Emergency. (1) This is the...

The Evolution of a Long-Lived Mesoscale Convective System Observed by GLM

NASA Astrophysics Data System (ADS)

Peterson, M. J.; Rudlosky, S. D.; Antunes, L.

2017-12-01

Continuous Geostationary Lightning Mapper (GLM) observations are used to document total lightning activity over the life cycle of a long-lived Mesoscale Convective System (MCS). MCS's may be few in number, but they are important for the Global Electric Circuit (GEC) because they sustain high lightning flash rates and quasi steady state conduction currents (Wilson currents) over longer time periods than ordinary isolated convection. The optical characteristics of the flashes produced by MCS's change over time, providing additional insights into the precipitation structure, convective mode, and evolution of the storm system. These insights are particularly useful in areas void of radar observations. Intercalibrated passive microwave radiometer data from the Global Precipitation Measurement (GPM) constellation also are used to estimate changes in Wilson current generation as the system evolves. These results highlight the role of MCS's in the GEC, and showcase how optical flash descriptors relate to thunderstorm organization, maturity, and structure.

High-performance multi-functional reverse osmosis membranes obtained by carbon nanotube·polyamide nanocomposite

PubMed Central

Inukai, Shigeki; Cruz-Silva, Rodolfo; Ortiz-Medina, Josue; Morelos-Gomez, Aaron; Takeuchi, Kenji; Hayashi, Takuya; Tanioka, Akihiko; Araki, Takumi; Tejima, Syogo; Noguchi, Toru; Terrones, Mauricio; Endo, Morinobu

2015-01-01

Clean water obtained by desalinating sea water or by purifying wastewater, constitutes a major technological objective in the so-called water century. In this work, a high-performance reverse osmosis (RO) composite thin membrane using multi-walled carbon nanotubes (MWCNT) and aromatic polyamide (PA), was successfully prepared by interfacial polymerization. The effect of MWCNT on the chlorine resistance, antifouling and desalination performances of the nanocomposite membranes were studied. We found that a suitable amount of MWCNT in PA, 15.5 wt.%, not only improves the membrane performance in terms of flow and antifouling, but also inhibits the chlorine degradation on these membranes. Therefore, the present results clearly establish a solid foundation towards more efficient large-scale water desalination and other water treatment processes. PMID:26333385

Water Desalination Using Nanoporous Single-Layer Graphene with Tunable Pore Size

DOE PAGES

Surwade, Sumedh P.; Smirnov, Sergei N.; Vlassiouk, Ivan V.; ...

2015-03-23

Graphene has great potential to serve as a separation membrane due to its unique properties such as chemical and mechanical stability, flexibility and most importantly its one-atom thickness. In this study, we demonstrate first experimental evidence of the use of single-layer porous graphene as a desalination membrane. Nanometer-sized pores are introduced into single layer graphene using a convenient oxygen plasma etching process that permits tuning of the pore size. The resulting porous graphene membrane exhibited high rejection of salt ions and rapid water transport, thus functioning as an efficient water desalination membrane. Salt rejection selectivity of nearly 100% and exceptionallymore » high water fluxes exceeding 105 g m-2 s-1 at 40 C were measured using saturated water vapor as a driving force.« less

Multi-Level Bitmap Indexes for Flash Memory Storage

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

Wu, Kesheng; Madduri, Kamesh; Canon, Shane

2010-07-23

Due to their low access latency, high read speed, and power-efficient operation, flash memory storage devices are rapidly emerging as an attractive alternative to traditional magnetic storage devices. However, tests show that the most efficient indexing methods are not able to take advantage of the flash memory storage devices. In this paper, we present a set of multi-level bitmap indexes that can effectively take advantage of flash storage devices. These indexing methods use coarsely binned indexes to answer queries approximately, and then use finely binned indexes to refine the answers. Our new methods read significantly lower volumes of data atmore » the expense of an increased disk access count, thus taking full advantage of the improved read speed and low access latency of flash devices. To demonstrate the advantage of these new indexes, we measure their performance on a number of storage systems using a standard data warehousing benchmark called the Set Query Benchmark. We observe that multi-level strategies on flash drives are up to 3 times faster than traditional indexing strategies on magnetic disk drives.« less

Wide Bandgap Semiconductor Detector Optimization for Flash X-Ray Measurements

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

Roecker, Caleb Daniel; Schirato, Richard C.

2017-11-17

Charge trapping, resulting in a decreased and spatially dependent electric field, has long been a concern for wide bandgap semiconductor detectors. While significant work has been performed to characterize this degradation at varying temperatures and radiation environments, this work concentrates upon examining the event-to-event response in a flash X-ray environment. The following work investigates if charge trapping is a problem for CZT detectors, with particular emphasis on flash X-ray radiation fields at cold temperatures. Results are compared to a non-flash radiation field, using an Am-241 alpha source and similar temperature transitions. Our ability to determine if a response change occurredmore » was hampered by the repeatability of our flash X-ray systems; a small response change was observed with the Am-241 source. Due to contrast of these results, we are in the process of revisiting the Am-241 measurements in the presence of a high radiation environment. If the response change is more pronounced in the high radiation environment, a similar test will be performed in the flash X-ray environment.« less

Regional reconstruction of flash flood history in the Guadarrama range (Central System, Spain).

PubMed

Rodriguez-Morata, C; Ballesteros-Cánovas, J A; Trappmann, D; Beniston, M; Stoffel, M

2016-04-15

Flash floods are a common natural hazard in Mediterranean mountain environments and responsible for serious economic and human disasters. The study of flash flood dynamics and their triggers is a key issue; however, the retrieval of historical data is often limited in mountain regions as a result of short time series and the systematic lack of historical data. In this study, we attempt to overcome data deficiency by supplementing existing records with dendrogeomorphic techniques which were employed in seven mountain streams along the northern slopes of the Guadarrama Mountain range. Here we present results derived from the tree-ring analysis of 117 samples from 63 Pinus sylvestris L. trees injured by flash floods, to complement existing flash flood records covering the last ~200years and comment on their hydro-meteorological triggers. To understand the varying number of reconstructed flash flood events in each of the catchments, we also performed a comparative analysis of geomorphic catchment characteristics, land use evolution and forest management. Furthermore, we discuss the limitations of dendrogeomorphic techniques applied in managed forests. Copyright © 2016 Elsevier B.V. All rights reserved.

Flash Floods Simulation Using a Physical based hydrological Model at the Eastern Nile Basin: Case studies; Wadi Assiut, Egypt and Wadi Gumara, Lake Tana, Ethiopia.

NASA Astrophysics Data System (ADS)

Saber, M.; Sefelnasr, A.; Yilmaz, K. K.

2015-12-01

Flash flood is a natural hydrological phenomenon which affects many regions of the world. The behavior and effect of this phenomenon is different from one region to the other regions depending on several issues such as climatology and hydrological and topographical conditions at the target regions. Wadi assiut, Egypt as arid environment, and Gumara catchment, Lake Tana, Ethiopia, as humid conditions have been selected for application. The main target of this work is to simulate flash floods at both catchments considering the difference between them on the flash flood behaviors based on the variability of both of them. In order to simulate the flash floods, remote sensing data and a physical-based distributed hydrological model, Hydro-BEAM-WaS (Hydrological River Basin Environmental Assessment Model incorporating Wadi System) have been integrated used in this work. Based on the simulation results of flash floods in these regions, it was found that the time to reach the maximum peak is very short and consequently the warning time is very short as well. It was found that the flash floods starts from zero flow in arid environment, but on the contrary in humid arid, it starts from Base flow which is changeable based on the simulated events. Distribution maps of flash floods showing the vulnerable regions of these selected areas have been developed. Consequently, some mitigation strategies relying on this study have been introduced. The proposed methodology can be applied effectively for flash flood forecasting at different climate regions, however the paucity of observational data.

[Effects of Suaeda glauca planting and straw mulching on soil salinity dynamics and desalination in extremely heavy saline soil of coastal areas.

PubMed

Zhang, Jiao; Cui, Shi You; Feng, Zhi Xiang

2018-05-01

To elucidate the seasonal variations in soil salinity and its driving factors, and to explore the effects of planting Suaeda glauca and straw mulching on soil desalination and salinity controlling, a field experiment was conducted in extremely heavy saline soil of coastal areas in Rudong, Jiangsu Province. There were four treatments: control (bare land, CK), planting S. glauca (PS), straw mulching A (at 15 t·hm -2 , SM-A), straw mulching 2A (at 30 t·hm -2 , SM-2A). Climate factors (including rainfall, atmospheric temperature, sunshine duration, and atmospheric evaporation) and soil salinity dynamic changes were determined from May 2014 to May 2015. Results showed that: (1) The seasonal variation of soil salinity was obvious in the bare ground (CK), with the lowest (8.69 g·kg -1 ) during June-August and the highest (26.66 g·kg -1 ) during September-December. The changes of soil salinity in topsoil (0-20 cm) were more intense than that in sub-topsoil (20-40 cm), with the changes in sub-topsoil having somewhat time lag compared the topsoil. (2) Soil salinity in CK treatment had a significantly linear correlation with the cumulative rainfall and evaporation-precipitation ratio of the fifteen-day before sampling. The results from multifactor and interphase analysis indicated that the increases of rainfall would promote soil desalinization. The rise of atmospheric temperature could exacerbate soil salt accumulation in surface soil. The interaction between rainfall and atmospheric temperature would have a positive effect on soil salt accumulation. (3) PS treatment did not alter the seasonal variation in soil salinity, but it reduced soil salinity in topsoil. (4) In SM-A and SM-2A treatments, the relationship of soil desalinization rate (%, Y) and treatment time (days, X) was expressed as Logistic curve equation. Moreover, the soil desalination rate was over 95.0% in the topsoil after 90-100 days of straw mul-ching treatment and was over 92.0% in sub-topsoil after 120 days of straw mulching treatment. The soil salinity in SM-A and SM-2A treatments fluctuated below 0.60 g·kg -1 and 1.00 g·kg -1 , respectively in topsoil and sub-topsoil. Considering the desalination and economic costs, a suitable amount of straw mulching (such as 15 t·hm -2 ) before rainy season was recommended, which would promote the soil desalinization and reclamation in extremely heavy saline soil of coastal areas.

Application of lightning data to satellite-based rainfall estimation

NASA Technical Reports Server (NTRS)

Martin, David W.; Hinton, Barry B.; Auvine, Brian A.

1991-01-01

Information on lightning may improve rain estimates made from infrared images of a geostationary satellite. We address this proposition through a case from the Cooperative Huntsville Meteorological Experiment (COHMEX). During the afternoon and evening of 13 July 1986 waves of showers and thunderstorms developed over and near the lower Tennessee River Valley. For the shower and thunderstorm region within 200 km of the National Weather Service radar at Nashville, Tennessee, we measure cold-cloud area in a sequence of GOES infrared images covering all but the end of the shower and thunderstorm period. From observations of the NASA/Marshall direction-finding network in this small domain, we also count cloud-to-ground lightning flashes and, from scans of the Nashville radar, we calculate volume rain flux. Using a modified version of the Williams and Houze scheme, over an area within roughly 240 km of the radar (the large domain), we identify and track cold cloud systems. For these systems, over the large domain, we measure area and count flashes; over the small domain, we calculate volume rain flux. For a temperature threshold of 235K, peak cloud area over the small domain lags both peak rain flux and peak flash count by about four hours. At a threshold of 226K, the lag is about two hours. Flashes and flux are matched in phase. Over the large domain, nine storm systems occur. These range in size from 300 to 60,000 km(exp 2); in lifetime, from about 2 1/2 h to 6 h or more. Storm system area lags volume rain flux and flash count; nevertheless, it is linked with these variables. In essential respects the associations were the same when clouds were defined by a threshold of 226K. Tentatively, we conclude that flash counts complement infrared images in providing significant additional information on rain flux.

A Temporal Locality-Aware Page-Mapped Flash Translation Layer

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

Kim, Youngjae; Gupta, Aayush; Urgaonkar, Bhuvan

2013-01-01

The poor performance of random writes has been a cause of major concern which needs to be addressed to better utilize the potential of flash in enterprise-scale environments. We examine one of the important causes of this poor performance: the design of the flash translation layer (FTL) which performs the virtual-to-physical address translations and hides the erase-before-write characteristics of flash. We propose a complete paradigm shift in the design of the core FTL engine from the existing techniques with our Demand-Based Flash Translation Layer (DFTL) which selectively caches page- level address mappings. Our experimental evaluation using FlashSim with realistic enterprise-scalemore » workloads endorses the utility of DFTL in enterprise-scale storage systems by demonstrating: 1) improved performance, 2) reduced garbage collection overhead and 3) better overload behavior compared with hybrid FTL schemes which are the most popular implementation methods. For example, a predominantly random-write dominant I/O trace from an OLTP application running at a large financial institution shows a 78% improvement in average response time (due to a 3-fold reduction in operations of the garbage collector), compared with the hybrid FTL scheme. Even for the well-known read-dominant TPC-H benchmark, for which DFTL introduces additional overheads, we improve system response time by 56%. Moreover, interestingly, when write-back cache on DFTL-based SSD is enabled, DFTL even outperforms the page-based FTL scheme, improving their response time by 72% in Financial trace.« less

Spectral measurements of muzzle flash with multispectral and hyperspectral sensor

NASA Astrophysics Data System (ADS)

Kastek, M.; Dulski, R.; Trzaskawka, P.; Piątkowski, T.; Polakowski, H.

2011-08-01

The paper presents some practical aspects of the measurements of muzzle flash signatures. Selected signatures of sniper shot in typical scenarios has been presented. Signatures registered during all phases of muzzle flash were analyzed. High precision laboratory measurements were made in a special ballistic laboratory and as a result several flash patterns were registered. The field measurements of a muzzle flash were also performed. During the tests several infrared cameras were used, including the measurement class devices with high accuracy and frame rates. The registrations were made in NWIR, SWIR and LWIR spectral bands simultaneously. An ultra fast visual camera was also used for visible spectra registration. Some typical infrared shot signatures were presented. Beside the cameras, the LWIR imaging spectroradiometer HyperCam was also used during the laboratory experiments and the field tests. The signatures collected by the HyperCam device were useful for the determination of spectral characteristics of the muzzle flash, whereas the analysis of thermal images registered during the tests provided the data on temperature distribution in the flash area. As a result of the measurement session the signatures of several types handguns, machine guns and sniper rifles were obtained which will be used in the development of passive infrared systems for sniper detection.

Nanotechnology: A Policy Primer

DTIC Science & Technology

2010-03-12

clean water. Nanotechnology water desalination and filtration systems may offer affordable, scalable, and portable water filtration...CRS Report for Congress Prepared for Members and Committees of Congress Nanotechnology : A Policy Primer John F. Sargent Jr. Specialist...DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Nanotechnology : A Policy Primer 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

Nanotechnology: A Policy Primer

DTIC Science & Technology

2010-01-04

clean water. Nanotechnology water desalination and filtration systems may offer affordable, scalable, and portable water filtration...CRS Report for Congress Prepared for Members and Committees of Congress Nanotechnology : A Policy Primer John F. Sargent Jr. Specialist...DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Nanotechnology : A Policy Primer 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

Teaching Mass Transfer and Filtration Using Crossflow Reverse Osmosis and Nanofiltration: An Experiment for the Undergraduate Unit Operations Lab

ERIC Educational Resources Information Center

Anastasio, Daniel; McCutcheon, Jeffrey

2012-01-01

A crossflow reverse osmosis (RO) system was built for a senior-level chemical engineering unit operations laboratory course. Intended to teach students mass transfer fundamentals related to membrane separations, students tested several commercial desalination membranes, measuring water flux and salt rejections at various pressures, flow rates, and…

Fluorimetric Detection of a Bacillus stearothermophilus Spore-Bound Enzyme, α-d-Glucosidase, for Rapid Indication of Flash Sterilization Failure

PubMed Central

Vesley, Donald; Langholz, Ann C.; Rohlfing, Stephen R.; Foltz, William E.

1992-01-01

A biological indicator based on fluorimetric detection within 60 min of a Bacillus stearothermophilus spore-bound enzyme, α-d-glucosidase, has been developed. Results indicate that the enzyme survived slightly longer than spores observed after 24 h of incubation. The new system shows promise for evaluating flash sterilization cycles within 60 min compared with conventional 24-h systems. PMID:16348654

Novel approach for low-cost muzzle flash detection system

NASA Astrophysics Data System (ADS)

Voskoboinik, Asher

2008-04-01

A low-cost muzzle flash detection based on CMOS sensor technology is proposed. This low-cost technology makes it possible to detect various transient events with characteristic times between dozens of microseconds up to dozens of milliseconds while sophisticated algorithms successfully separate them from false alarms by utilizing differences in geometrical characteristics and/or temporal signatures. The proposed system consists of off-the-shelf smart CMOS cameras with built-in signal and image processing capabilities for pre-processing together with allocated memory for storing a buffer of images for further post-processing. Such a sensor does not require sending giant amounts of raw data to a real-time processing unit but provides all calculations in-situ where processing results are the output of the sensor. This patented CMOS muzzle flash detection concept exhibits high-performance detection capability with very low false-alarm rates. It was found that most false-alarms due to sun glints are from sources at distances of 500-700 meters from the sensor and can be distinguished by time examination techniques from muzzle flash signals. This will enable to eliminate up to 80% of falsealarms due to sun specular reflections in the battle field. Additional effort to distinguish sun glints from suspected muzzle flash signal is made by optimization of the spectral band in Near-IR region. The proposed system can be used for muzzle detection of small arms, missiles and rockets and other military applications.

NAFFS: network attached flash file system for cloud storage on portable consumer electronics

NASA Astrophysics Data System (ADS)

Han, Lin; Huang, Hao; Xie, Changsheng

Cloud storage technology has become a research hotspot in recent years, while the existing cloud storage services are mainly designed for data storage needs with stable high speed Internet connection. Mobile Internet connections are often unstable and the speed is relatively low. These native features of mobile Internet limit the use of cloud storage in portable consumer electronics. The Network Attached Flash File System (NAFFS) presented the idea of taking the portable device built-in NAND flash memory as the front-end cache of virtualized cloud storage device. Modern portable devices with Internet connection have built-in more than 1GB NAND Flash, which is quite enough for daily data storage. The data transfer rate of NAND flash device is much higher than mobile Internet connections[1], and its non-volatile feature makes it very suitable as the cache device of Internet cloud storage on portable device, which often have unstable power supply and intermittent Internet connection. In the present work, NAFFS is evaluated with several benchmarks, and its performance is compared with traditional network attached file systems, such as NFS. Our evaluation results indicate that the NAFFS achieves an average accessing speed of 3.38MB/s, which is about 3 times faster than directly accessing cloud storage by mobile Internet connection， and offers a more stable interface than that of directly using cloud storage API. Unstable Internet connection and sudden power off condition are tolerable, and no data in cache will be lost in such situation.

Coupling Flash LC with MS for enrichment and isolation of milk oligosaccharides for functional studies

PubMed Central

Strum, John S.; Aldredge, Danielle; Barile, Daniela; Lebrilla, Carlito B.

2013-01-01

Mass spectrometry has been coupled with flash liquid chromatography to yield new capabilities for isolating non-chromophoric material from complicated biological mixtures. A flash LC/MS/MS method enabled fraction collection of milk oligosaccharides from biological mixtures based on composition and structure. The method is compatible with traditional gas-pressure driven flow flash chromatography, widely employed in organic chemistry laboratories. The on-line mass detector enabled real-time optimization of chromatographic parameters to favor separation of oligosaccharides that would otherwise be indistinguishable from co-eluting components with a non-specific detector. Unlike previously described preparative LC/MS techniques, we have employed a dynamic flow connection that permits any flow rate from the flash system to be delivered from 1–200 mL/min without affecting the ionization conditions of the mass spectrometer. A new way of packing large amounts of graphitized carbon allowed the enrichment and separation of milligram quantities of structurally heterogeneous mixtures of human milk oligosaccharides (HMOs) and bovine milk oligosaccharides (BMOs). Abundant saccharide components in milk, such as lactose and lacto-N-tetraose, were separated from the rarer and less abundant oligosaccharides that have greater structural diversity and biological functionality. Neutral and acidic HMOs and BMOs were largely separated and enriched with a dual binary solvent system. PMID:22370281

Isolation of methyl gamma linolenate from Spirulina platensis using flash chromatography and its apoptosis inducing effect.

PubMed

Jubie, S; Dhanabal, S P; Chaitanya, M V N L

2015-08-04

Isolation of methyl gamma linolenate from Spirulina platensis using flash chromatography and its apoptosis inducing effect against human lung carcinoma A- 549 cell lines. Gamma linolenic acid is an important omega-6 polyunsaturated fatty acid (PUFA) of medicinal interest was isolated from microalgae Spirulina platensis using flash chromatography system (Isolera system) as its methyl ester. The isolated methyl gamma linolenate was characterized by IR, (1)H NMR, (13)C NMR and mass spectral analysis and the data were consistent with the structure. The percentage yield of isolated methyl gamma linolenate is found to be 71% w/w, which is a very good yield in comparison to other conventional methods. It was subjected to in-vitro cytotoxic screening on A-549 lung cancer cell lines using SRB assay and result was compared with standard rutin. It may be concluded that the Flash chromatography system plays a major role in improving the yield for the isolation of methyl gamma linoleate from Spirulina platensis and the isolated molecule is a potent cytotoxic agent towards human lung carcinoma cell lines, however it may be further taken up for an extensive study.

What affects public acceptance of recycled and desalinated water?

PubMed Central

Dolnicar, Sara; Hurlimann, Anna; Grün, Bettina

2011-01-01

This paper identifies factors that are associated with higher levels of public acceptance for recycled and desalinated water. For the first time, a wide range of hypothesized factors, both of socio-demographic and psychographic nature, are included simultaneously. The key results, based on a survey study of about 3000 respondents are that: (1) drivers of the stated likelihood of using desalinated water differ somewhat from drivers of the stated likelihood of using recycled water; (2) positive perceptions of, and knowledge about, the respective water source are key drivers for the stated likelihood of usage; and (3) awareness of water scarcity, as well as prior experience with using water from alternative sources, increases the stated likelihood of use. Practical recommendations for public policy makers, such as key messages to be communicated to the public, are derived. PMID:20950834

Response of amphipod assemblages to desalination brine discharge: Impact and recovery

NASA Astrophysics Data System (ADS)

de-la-Ossa-Carretero, J. A.; Del-Pilar-Ruso, Y.; Loya-Fernández, A.; Ferrero-Vicente, L. M.; Marco-Méndez, C.; Martinez-Garcia, E.; Sánchez-Lizaso, J. L.

2016-04-01

Desalination has become an important industry whose dense, high-salinity effluent has an impact on marine communities. Without adequate dilution, brine remains on the bottom increasing bottom salinity and affecting benthic communities. Amphipods showed high sensitivity to increased salinity produced by desalination brine discharge. A decrease in abundance and diversity of amphipods was detected at the station closest to the outfall, where salinity values reached 53. This salinity was later reduced by including a diffuser at the end of the pipeline. Six months after diffuser installation, amphipod abundance increased. During the first stage of this recovery, species such as Photis longipes recovered their abundance, others such as Microdeutopus versiculatus displayed opportunistic patterns, while others needed more time for recovery, e.g. Harpinia pectinata. These differences may be dependent on the organism living habits.

Constructing Black Titania with Unique Nanocage Structure for Solar Desalination.

PubMed

Zhu, Guilian; Xu, Jijian; Zhao, Wenli; Huang, Fuqiang

2016-11-23

Solar desalination driven by solar radiation as heat source is freely available, however, hindered by low efficiency. Herein, we first design and synthesize black titania with a unique nanocage structure simultaneously with light trapping effect to enhance light harvesting, well-crystallized interconnected nanograins to accelerate the heat transfer from titania to water and with opening mesopores (4-10 nm) to facilitate the permeation of water vapor. Furthermore, the coated self-floating black titania nanocages film localizes the temperature increase at the water-air interface rather than uniformly heating the bulk of the water, which ultimately results in a solar-thermal conversion efficiency as high as 70.9% under a simulated solar light with an intensity of 1 kW m -2 (1 sun). This finding should inspire new black materials with rationally designed structure for superior solar desalination performance.

Incorporating Lightning Flash Data into the WRF-CMAQ Modeling System: Algorithms and Evaluations

EPA Science Inventory

We describe the use of lightning flash data from the National Lightning Detection Network (NLDN) to constrain and improve the performance of coupled meteorology-chemistry models. We recently implemented a scheme in which lightning data is used to control the triggering of conve...

Impact of Operating Rules on Planning Capacity Expansion of Urban Water Supply Systems

NASA Astrophysics Data System (ADS)

de Neufville, R.; Galelli, S.; Tian, X.

2017-12-01

This study addresses the impact of operating rules on capacity planning of urban water supply systems. The continuous growth of metropolitan areas represents a major challenge for water utilities, which often rely on industrial water supply (e.g., desalination, reclaimed water) to complement natural resources (e.g., reservoirs). These additional sources increase the reliability of supply, equipping operators with additional means to hedge against droughts. How do their rules for using industrial water supply impact the performance of water supply system? How might it affect long-term plans for capacity expansion? Possibly significantly, as demonstrated by the analysis of the operations and planning of a water supply system inspired by Singapore. Our analysis explores the system dynamics under multiple inflow and management scenarios to understand the extent to which alternative operating rules for the use of industrial water supply affect system performance. Results first show that these operating rules can have significant impact on the variability in system performance (e.g., reliability, energy use) comparable to that of hydro-climatological conditions. Further analyses of several capacity expansion exercises—based on our original hydrological and management scenarios—show that operating rules significantly affect the timing and magnitude of critical decisions, such as the construction of new desalination plants. These results have two implications: Capacity expansion analysis should consider the effect of a priori uncertainty about operating rules; and operators should consider how their flexibility in operating rules can affect their perceived need for capacity.

A geopressured-geothermal, solar conversion system to produce potable water

NASA Astrophysics Data System (ADS)

Nitschke, George Samuel

A design is presented for recovering Geopressured-Geothermal (GPGT) reservoir brines for conversion into solar ponds to renewably power coastal seawater desalination. The hot, gas-cut, high-pressure GPGT brine is flowed through a well-bore to surface systems which concentrate the brine in multi-effect evaporators and recover the gas. The gas and distilled water are used for thermal enhanced oil recovery, and the concentrated brine is used to construct solar ponds. The thermal energy from the solar ponds is used to produce electricity, which is then used to renewably power coastal desalination plants for large-scale potable water production from the sea. The design is proposed for deployment in California and Texas, where the two largest U.S. GPGT basins exist. Projections show that the design fully deployed in California could provide 5 MAF/y (million acre-ft per year) while yielding a 45% Rate of Return (combined oil and water revenues); the California municipal water load is 10 MAF/y. The dissertation contains a feasibility study of the design approach, supported by engineering analyses and simulation models, included in the appendices. A range of systems configurations and GPGT flow conditions are modeled to illustrate how the approach lends itself to modular implementation, i.e., incrementally installing a single system, tens of systems, up to 1000 systems, which corresponds to full deployment in California for the scenario analyzed. The dissertation includes a method for launching and piloting the approach, starting from a single system installation.

Water desalination by electrical resonance inside carbon nanotubes.

PubMed

Feng, Jia-Wei; Ding, Hong-Ming; Ma, Yu-Qiang

2016-10-12

Although previous studies have indicated that the carbon nanotube (CNT) can be used for directed transportation of water and ions, it is still a challenging problem to design a CNT-based device for high performance water desalination. In this study, by using molecular dynamics simulations, we successfully design one type of CNT as a highly efficient desalination membrane through electrical resonance. By decorating the two ends of the CNT with vibrational charges, an alternating electric field is created inside the CNT. When the amplitude of the vibrational charge is 0.05 e, and the vibrational frequency is between 10 THz and 20 THz, the CNT can completely block the transportation of ions. The decrease of the amplitude or the deviation of the frequency in an appropriate range will gradually increase the ion flow. Besides, we also reveal the underlying molecular mechanism of ion blockage, i.e., the electric resonance can disrupt the water structure inside the CNT and then alter the hydration energy of ions inside the CNT. More importantly, we further demonstrate that this mechanism is universal, which is independent of the type of ions and the size of CNT. The present work could be useful for designing water desalination membranes with lower energy consumption and higher fresh water production.

Desalination of simulated seawater by purge-air pervaporation using an innovative fabricated membrane.

PubMed

Naim, Mona; Elewa, Mahmoud; El-Shafei, Ahmed; Moneer, Abeer

2015-01-01

An innovative polymeric membrane has been invented, which presents a breakthrough in the field of desalination membranes. It can desalinate simulated seawater of exceptionally high concentration to produce a high flux of potable water with over 99.7% salt rejection (%SR) in a once-through purge-air pervaporation (PV) process. A set-up was constructed for conducting the desalination experiments and the effect of initial salt solution concentration (Ci) and pervaporation temperature (Tpv) on the water flux (J), %SR, separation factor, and pervaporation separation index were determined. The membrane was prepared by the phase-inversion technique, of a specially formulated casting solution consisting of five ingredients, after which the membrane was subjected to a post-treatment by which certain properties were conferred. The results confirmed that the salinity of the pervaporate was independent of Ci (all %SR above 99.7). The best result was at Tpv=70 °C, where J varied from 5.97 to 3.45 l/m2 h for Ci=40-140 g NaCl/l, respectively. The membrane morphology was confirmed to be asymmetric. The contact angle was immeasurable, indicating the membrane to be super-hydrophilic. Activation energies computed using Arrhenius law were, under all conditions investigated, less than 20 kJ/mol K.

Plasmonic heating from indium nanoparticles on a floating microporous membrane for enhanced solar seawater desalination.

PubMed

Zhang, Lulu; Xing, Jun; Wen, Xinglin; Chai, Jianwei; Wang, Shijie; Xiong, Qihua

2017-09-14

Passive solar evaporation represents a promising and environmentally benign method of water purification/desalination. Plasmonic nanoparticles have been demonstrated as an effective approach for enhancing solar steam generation through a plasmonic heating effect, nonetheless the efficiency is constrained by unnecessary bulk heating of the entire liquid volume, while the noble metals commonly used are not cost-effective in terms of availability and their sophisticated preparation. Herein, a paper-like plasmonic device consisting of a microporous membrane and indium nanoparticles (In NPs/MPM) is fabricated through a simple thermal evaporation method. Due to the light-weight and porous nature of the device, the broadband light absorption properties, and theoretically the excellent plasmonic heating effect from In NP which could be even higher than gold, silver and aluminium nanoparticles, our device can effectively enhance solar water evaporation by floating on the water surface and its utility has been demonstrated in the solar desalination of a real seawater sample. The durability of the device in solar seawater desalination has also been investigated over multiple cycles with stable performances. This portable device could provide a solution for individuals to do water/seawater purification in under-developed areas with limited/no access to electricity or a centralized drinking water supply.

Wash water recovery system

NASA Technical Reports Server (NTRS)

Deckman, G.; Rousseau, J. (Editor)

1973-01-01

The Wash Water Recovery System (WWRS) is intended for use in processing shower bath water onboard a spacecraft. The WWRS utilizes flash evaporation, vapor compression, and pyrolytic reaction to process the wash water to allow recovery of potable water. Wash water flashing and foaming characteristics, are evaluated physical properties, of concentrated wash water are determined, and a long term feasibility study on the system is performed. In addition, a computer analysis of the system and a detail design of a 10 lb/hr vortex-type water vapor compressor were completed. The computer analysis also sized remaining system components on the basis of the new vortex compressor design.

Electro-optical muzzle flash detection

NASA Astrophysics Data System (ADS)

Krieg, Jürgen; Eisele, Christian; Seiffer, Dirk

2016-10-01

Localizing a shooter in a complex scenario is a difficult task. Acoustic sensors can be used to detect blast waves. Radar technology permits detection of the projectile. A third method is to detect the muzzle flash using electro-optical devices. Detection of muzzle flash events is possible with focal plane arrays, line and single element detectors. In this paper, we will show that the detection of a muzzle flash works well in the shortwave infrared spectral range. Important for the acceptance of an operational warning system in daily use is a very low false alarm rate. Using data from a detector with a high sampling rate the temporal signature of a potential muzzle flash event can be analyzed and the false alarm rate can be reduced. Another important issue is the realization of an omnidirectional view required on an operational level. It will be shown that a combination of single element detectors and simple optics in an appropriate configuration is a capable solution.

Evaluation of Internet websites about floaters and light flashes in patient education.

PubMed

Barbosa, Andréa Lima; Martins, Elisabeth Nogueira

2007-01-01

Flashes of light and floaters are most commonly caused by posterior vitreous separation but may be associated with sight-threatening disorders. Prevention of severe sequelae requires prompt dilated eye examination. Thus, information dissemination is crucial. This study aimed to evaluate the quality of information about floaters and light flashes available for patients on the Internet. Cross-sectional study. In July 2005 we evaluated information available on the Internet regarding floaters and light flashes, using two search engines (MetaCrawler and MSN) and three key terms ("floaters", "dark spots eye", and "light flashes eye"). The quality of each website was evaluated using a score system. The sites were classified as academic, organizational or commercial. Readability, general quality of the website (based on: ownership, purpose, authorship, author qualification, attribution, interactivity, and currency) and quality of the specific content (definition, causes, epidemiology, diagnosis, treatment, and prognosis) were analyzed. Of 145 websites evaluated, 49 were included. Four sites (8.2%) were academic, 9 (18.4%) organizational, and 36 (73.4%) commercial. In the majority of the sites (53.0%) information was poor and quality was not correlated with website classification. Information about floaters and light flashes available on the Internet is poor.

Representative shuttle evaporative heat sink

NASA Technical Reports Server (NTRS)

Hixon, C. W.

1978-01-01

The design, fabrication, and testing of a representative shuttle evaporative heat sink (RSEHS) system which vaporizes an expendable fluid to provide cooling for the shuttle heat transport fluid loop is reported. The optimized RSEHS minimum weight design meets or exceeds the shuttle flash evaporator system requirements. A cold trap which cryo-pumps flash evaporator exhaust water from the CSD vacuum chamber test facility to prevent water contamination of the chamber pumping equipment is also described.

Flash evaporator systems test

NASA Technical Reports Server (NTRS)

Dietz, J. B.

1976-01-01

A flash evaporator heat rejection system representative of that proposed for the space shuttle orbiter underwent extensive system testing at the NASA Johnson Space Center (JSC) to determine its operational suitability and to establish system performance/operational characteristics for use in the shuttle system. During the tests the evaporator system demonstrated its suitability to meet the shuttle requirements by: (1) efficient operation with 90 to 95% water evaporation efficiency, (2) control of outlet temperature to 40 + or - 2 F for partial heat load operation, (3) stability of control system for rapid changes in Freon inlet temperature, and (4) repeated dormant-to-active device operation without any startup procedures.

Spectroscopic temperature measurements in interior ballistic environments

NASA Astrophysics Data System (ADS)

Klingenberg, G.; Mach, H.

1984-11-01

Spectroscopic temperature measurements during the interior ballistic cycle of a 20 mm test fixture gun and inside the muzzle flash of a 7.62 mm rifle are described. The investigation yields information on temperature distribution in the burning propellant charge of the 20 mm test fixture and on radial temperature profiles in the 7.62 mm muzzle flash region. A technique to obtain temperature during the ignition and combustion within the 20 mm propellant charge is presented. Additional in-bore measurements by quartz windows mounted into bores along the barrel and emission-absorption measurements inside the muzzle flash of the 20 mm test fixture yield a complete temperature profile for the gun system. Spectroscopic infrared measurements inside the muzzle flash of a 7.62 mm rifle complete the investigation.

Imaging Flash Lidar for Autonomous Safe Landing and Spacecraft Proximity Operation

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin; Roback, Vincent E.; Brewster, Paul F.; Hines, Glenn D.; Bulyshev, Alexander E.

2016-01-01

3-D Imaging flash lidar is recognized as a primary candidate sensor for safe precision landing on solar system bodies (Moon, Mars, Jupiter and Saturn moons, etc.), and autonomous rendezvous proximity operations and docking/capture necessary for asteroid sample return and redirect missions, spacecraft docking, satellite servicing, and space debris removal. During the final stages of landing, from about 1 km to 500 m above the ground, the flash lidar can generate 3-Dimensional images of the terrain to identify hazardous features such as craters, rocks, and steep slopes. The onboard fli1ght computer can then use the 3-D map of terrain to guide the vehicle to a safe location. As an automated rendezvous and docking sensor, the flash lidar can provide relative range, velocity, and bearing from an approaching spacecraft to another spacecraft or a space station from several kilometers distance. NASA Langley Research Center has developed and demonstrated a flash lidar sensor system capable of generating 16k pixels range images with 7 cm precision, at a 20 Hz frame rate, from a maximum slant range of 1800 m from the target area. This paper describes the lidar instrument design and capabilities as demonstrated by the closed-loop flight tests onboard a rocket-propelled free-flyer vehicle (Morpheus). Then a plan for continued advancement of the flash lidar technology will be explained. This proposed plan is aimed at the development of a common sensor that with a modest design adjustment can meet the needs of both landing and proximity operation and docking applications.

Atom Resolved Electron Microscpe Images of Polyvinylidene Fluoride Nanofibers for Water Desalination

NASA Astrophysics Data System (ADS)

Liu, Suqi; Reneker, Darrell

Ultra-thin nanofibers of polyvinylidene fluoride (PVDF), observed with an aberration corrected transmission electron microscope, in a through focus series of 50 images, revealed three-dimensional positions and motions of some molecular segments. The x,y positions of fluorine atoms in the PVDF segments were observed at high resolution as described in (DOI: 10.1039/c5nr01619c). The methods described in (DOI:10.1038/nature11074) were used to measure the positions of fluorine atoms along the observation direction of the microscope. PVDF is widely used to separate salt ions from water in reverse osmosis systems. The observed separation depends on the atomic scale positions and motions of segments of the PVDF molecules. Conformational changes and the associated changes in the directions of the dipole moments of PVDF segments distinguish the diffusion of dipolar water molecules from diffusion of salt ions to accomplish desalination. Authors thank Coalescence Filtration Nanofibers Consortium at The University of Akron for support.

FlaME: Flash Molecular Editor - a 2D structure input tool for the web.

PubMed

Dallakian, Pavel; Haider, Norbert

2011-02-01

So far, there have been no Flash-based web tools available for chemical structure input. The authors herein present a feasibility study, aiming at the development of a compact and easy-to-use 2D structure editor, using Adobe's Flash technology and its programming language, ActionScript. As a reference model application from the Java world, we selected the Java Molecular Editor (JME). In this feasibility study, we made an attempt to realize a subset of JME's functionality in the Flash Molecular Editor (FlaME) utility. These basic capabilities are: structure input, editing and depiction of single molecules, data import and export in molfile format. The result of molecular diagram sketching in FlaME is accessible in V2000 molfile format. By integrating the molecular editor into a web page, its communication with the HTML elements on this page is established using the two JavaScript functions, getMol() and setMol(). In addition, structures can be copied to the system clipboard. A first attempt was made to create a compact single-file application for 2D molecular structure input/editing on the web, based on Flash technology. With the application examples presented in this article, it could be demonstrated that the Flash methods are principally well-suited to provide the requisite communication between the Flash object (application) and the HTML elements on a web page, using JavaScript functions.

Relaciones hidrogeologicas y medioambientales entre el mar mediterraneo, El saladar y el acuifero de agua amarga (provincia de alicante). Incidencia de las explotaciones de las desaladoras de alicante I Y II Y medidas correctoras

NASA Astrophysics Data System (ADS)

Manteca, Ivan Alhama

The Agua Amarga coastal aquifer, located in the south of Alicante province, has been subjected to successive anthropogenic actions: salt works activity (1925-1975) and water withdrawal to supply the Alicante I and II desalination plants (since 2003). These interventions have influenced the salinity and the flow regime. Due to the existence of a salt marsh of ecological interest linked to the aquifer, the 'Mancomunidad de los Canales del Taibilla' (agency responsible for the desalination plants) designed a piezometric network for monitoring piezometry and electrical conductivity (in operation since May 2008). Soil humidity and piezometrics levels have been recovered by means of a seawater pouring programme over the salt marsh (since December 2009),which represents the third anthropic intervention. In this memoria, we investigate the Agua Amarga coastal aquifer to develop a physical conceptual model. Firstly, the study area is characterized in relation to climatology, geology, geomorphology and hydrogeology, using published information, describing, in addition, the desalination plants catchment system. Next, based on hydrogeological studies prior to the start up of the desalination plants, the aquifer is characterized: type, lithology, hydraulic parameters, thickness, surface extension, etc. Water quantity relating to rainfall, water withdrawal and pourings over the salt marsh, have been integrated in conjunction with data from monthly piezometric campaigns. In adittion, in order to gain insight into the groundwater mixing processes, chemical and isotope analyses were carried out on meteoric water and groundwater samples taken at different locations. The results were used to elaborate a conceptual physical model and a water budget. As an extension tool to understand processes and assess aquifer management, a 3-D fluid-flow and solute-transport model is designed with SEAWAT. Also, the 2-D physical characterization of scenarios with seawater intrusion and salt flats is presented. Finally, after describing ecological values of the salt marsh, the effect of the seawater pouring programme on aquifer piezometry and salinity is studied, assessing the possibility of applying this pilot scheme to other scenarios.

Geophysical remote sensing of water reservoirs suitable for desalinization.

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

Aldridge, David Franklin; Bartel, Lewis Clark; Bonal, Nedra

2009-12-01

In many parts of the United States, as well as other regions of the world, competing demands for fresh water or water suitable for desalination are outstripping sustainable supplies. In these areas, new water supplies are necessary to sustain economic development and agricultural uses, as well as support expanding populations, particularly in the Southwestern United States. Increasing the supply of water will more than likely come through desalinization of water reservoirs that are not suitable for present use. Surface-deployed seismic and electromagnetic (EM) methods have the potential for addressing these critical issues within large volumes of an aquifer at amore » lower cost than drilling and sampling. However, for detailed analysis of the water quality, some sampling utilizing boreholes would be required with geophysical methods being employed to extrapolate these sampled results to non-sampled regions of the aquifer. The research in this report addresses using seismic and EM methods in two complimentary ways to aid in the identification of water reservoirs that are suitable for desalinization. The first method uses the seismic data to constrain the earth structure so that detailed EM modeling can estimate the pore water conductivity, and hence the salinity. The second method utilizes the coupling of seismic and EM waves through the seismo-electric (conversion of seismic energy to electrical energy) and the electro-seismic (conversion of electrical energy to seismic energy) to estimate the salinity of the target aquifer. Analytic 1D solutions to coupled pressure and electric wave propagation demonstrate the types of waves one expects when using a seismic or electric source. A 2D seismo-electric/electro-seismic is developed to demonstrate the coupled seismic and EM system. For finite-difference modeling, the seismic and EM wave propagation algorithms are on different spatial and temporal scales. We present a method to solve multiple, finite-difference physics problems that has application beyond the present use. A limited field experiment was conducted to assess the seismo-electric effect. Due to a variety of problems, the observation of the electric field due to a seismic source is not definitive.« less

Spontaneous water filtration of bio-inspired membrane

NASA Astrophysics Data System (ADS)

Kim, Kiwoong; Kim, Hyejeong; Lee, Sang Joon

2016-11-01

Water is one of the most important elements for plants, because it is essential for various metabolic activities. Thus, water management systems of vascular plants, such as water collection and water filtration have been optimized through a long history. In this view point, bio-inspired technologies can be developed by mimicking the nature's strategies for the survival of the fittest. However, most of the underlying biophysical features of the optimized water management systems remain unsolved In this study, the biophysical characteristics of water filtration phenomena in the roots of mangrove are experimentally investigated. To understand water-filtration features of the mangrove, the morphological structures of its roots are analyzed. The electrokinetic properties of the root surface are also examined. Based on the quantitatively analyzed information, filtration of sodium ions in the roots are visualized. Motivated by this mechanism, spontaneous desalination mechanism in the root of mangrove is proposed by combining the electrokinetics and hydrodynamic transportation of ions. This study would be helpful for understanding the water-filtration mechanism of the roots of mangrove and developing a new bio-inspired desalination technology. This research was financially supported by the National Research Foundation (NRF) of Korea (Contract Grant Number: 2008-0061991).

A natural driven membrane process for brackish and wastewater treatment: photovoltaic powered ED and FO hybrid system.

PubMed

Zhang, Yang; Pinoy, Luc; Meesschaert, Boudewijn; Van der Bruggen, Bart

2013-09-17

In isolated locations, remote areas, or islands, potable water is precious because of the lack of drinking water treatment facilities and energy supply. Thus, a robust and reliable water treatment system based on natural energy is needed to reuse wastewater or to desalinate groundwater/seawater for provision of drinking water. In this work, a hybrid membrane system combining electrodialysis (ED) and forward osmosis (FO), driven by renewable energy (solar energy), denoted as EDFORD (ED-FO Renewable energy Desalination), is proposed to produce high-quality water (potable) from secondary wastewater effluent or brackish water. In this hybrid membrane system, feedwater (secondary wastewater effluent or synthetic brackish water) was drawn to the FO draw solution while the organic and inorganic substances (ions, compounds, colloids and particles) were rejected. The diluted draw solution was then pumped to the solar energy driven ED. In the ED unit, the diluted draw solution was desalted and high-quality water was produced; the concentrate was recycled to the FO unit and reused as the draw solution. Results show that the water produced from this system contains a low concentration of total organic carbon (TOC), carbonate, and cations derived from the feedwater; had a low conductivity; and meets potable water standards. The water production cost considering the investment for membranes and solar panel is 3.32 to 4.92 EUR m(-3) (for 300 days of production per year) for a small size potable water production system.

Qualitative assessment of contrast-enhanced magnetic resonance angiography using breath-hold and non-breath-hold techniques in the portal venous system

NASA Astrophysics Data System (ADS)

Goo, Eun-Hoe; Kim, Sun-Ju; Dong, Kyung-Rae; Kim, Kwang-Choul; Chung, Woon-Kwan

2016-09-01

The purpose of this study is to evaluate the image quality in delineation of the portal venous systems with two different methods, breath-hold and non-breath-hold by using the 3D FLASH sequence. We used a 1.5 T system to obtain magnetic resonance(MR)images. Arterial and portal phase 3D FLASH images were obtained with breath-hold after a bolus injection of GD-DOTA. The detection of PVS on the MR angiograms was classified into three grades. First, the angiograms of the breath-hold method showed well the portal vein, the splenic vein and the superior mesenteric vein systems in 13 of 15 patients (86%) and the inferior mesenteric vein system in 6 of 15 patients (40%), Second, MR angiograms of the non-breath-hold method demonstrated the PVS and the SMV in 12 of 15 patients (80%) and the IMV in 5 of 15 patients (33%). Our study showed contrast-enhanced 3D FLASH MR angiography, together with the breath-hold technique, may provide reliable and accurate information on the portal venous system.

Solar technology in the Federal Republic of Germany

NASA Technical Reports Server (NTRS)

1979-01-01

A series of papers dealing with the status of solar research and development in the Federal Republic of Germany are presented at a conference in Greece with the object of promoting international cooperation in solar energy utilization. The reports focus on solar collector designs, solar systems, heat pumps, solar homes, solar cooling and refrigeration, desalination and electric power generation. Numerous examples of systems produced by German manufacturers are illustrated and described, and performance data are presented.

Dynamic flashing yellow arrow (FYA): a study on variable left-turn mode operational and safety impacts phase II - model expansion and testing.

DOT National Transportation Integrated Search

2016-06-01

The flashing yellow arrow (FYA) signal display creates an opportunity to enhance the left-turn phase with a : variable mode that can be changed on demand. The previously developed decision support system (DSS) in : phase I facilitated the selection o...

INHIBITION OF BRAIN CHOLINESTERASE AND THE PHOTIC AFTER DISCHARGE OF FLASH EVOKED POTENTIALS PRODUCED BY CARBARYL IN LONG EVANS RATS.

EPA Science Inventory

Carbaryl is a widely used N-methyl carbamate pesticide that acts by inhibiting cholinesterases (ChE), which may lead to cholinergic toxicity. Flash evoked potentials (FEPs) are a neurophysiological response often used to detect central nervous system (CNS) changes following expos...

High Risk Flash Flood Rainstorm Mapping Based on Regional L-moments Approach

NASA Astrophysics Data System (ADS)

Ding, Hui; Liao, Yifan; Lin, Bingzhang

2017-04-01

Difficulties and complexities in elaborating flash flood early-warning and forecasting system prompt hydrologists to develop some techniques to substantially reduce the disastrous outcome of a flash flood in advance. An ideal to specify those areas that are subject at high risk to flash flood in terms of rainfall intensity in a relatively large region is proposed in this paper. It is accomplished through design of the High Risk Flash Flood Rainstorm Area (HRFFRA) based on statistical analysis of historical rainfall data, synoptic analysis of prevailing storm rainfalls as well as the field survey of historical flash flood events in the region. A HRFFRA is defined as the area potentially under hitting by higher intense-precipitation for a given duration with certain return period that may cause a flash flood disaster in the area. This paper has presented in detail the development of the HRFFRA through the application of the end-to-end Regional L-moments Approach (RLMA) to precipitation frequency analysis in combination with the technique of spatial interpolation in Jiangxi Province, South China Mainland. Among others, the concept of hydrometeorologically homogenous region, the precision of frequency analysis in terms of parameter estimation, the accuracy of quantiles in terms of uncertainties and the consistency adjustments of quantiles over durations and space, etc., have been addressed. At the end of this paper, the mapping of the HRFFRA and an internet-based visualized user-friendly data-server of the HRFFRA are also introduced. Key words: HRFFRA; Flash Flood; RLMA; rainfall intensity; Hydrometeorological homogenous region.

Desalination with Carbon Aerogel Electrodes

DTIC Science & Technology

1996-12-04

Desalination with Carbon Aerogel Electrodes Joseph C. Farmer, Jeffrey H Richardson and David V Fix Chemistry and Materials Science Department Lawrence...Department of Interior, 190 pages, May (1966). 9. A. M. Johnson, A. W. Venolia, J. Newman, R. G. Wilbourne , C. M. Wong,, W. S. Gillam, S. Johnson, R. H...200 056, 31 pages, March (1970). 10. A. M. Johnson, A. W. Venolia, R. G. Wilbourne , J. Newman, "The Electrosorb Process for Desalting Water," Marquardt

Coupling Radar Rainfall Estimation and Hydrological Modelling For Flash-flood Hazard Mitigation

NASA Astrophysics Data System (ADS)

Borga, M.; Creutin, J. D.

Flood risk mitigation is accomplished through managing either or both the hazard and vulnerability. Flood hazard may be reduced through structural measures which alter the frequency of flood levels in the area. The vulnerability of a community to flood loss can be mitigated through changing or regulating land use and through flood warning and effective emergency response. When dealing with flash-flood hazard, it is gener- ally accepted that the most effective way (and in many instances the only affordable in a sustainable perspective) to mitigate the risk is by reducing the vulnerability of the involved communities, in particular by implementing flood warning systems and community self-help programs. However, both the inherent characteristics of the at- mospheric and hydrologic processes involved in flash-flooding and the changing soci- etal needs provide a tremendous challenge to traditional flood forecasting and warning concepts. In fact, the targets of these systems are traditionally localised like urbanised sectors or hydraulic structures. Given the small spatial scale that characterises flash floods and the development of dispersed urbanisation, transportation, green tourism and water sports, human lives and property are exposed to flash flood risk in a scat- tered manner. This must be taken into consideration in flash flood warning strategies and the investigated region should be considered as a whole and every section of the drainage network as a potential target for hydrological warnings. Radar technology offers the potential to provide information describing rain intensities almost contin- uously in time and space. Recent research results indicate that coupling radar infor- mation to distributed hydrologic modelling can provide hydrologic forecasts at all potentially flooded points of a region. Nevertheless, very few flood warning services use radar data more than on a qualitative basis. After a short review of current under- standing in this area, two issues are examined: advantages and caveats of using radar rainfall estimates in operational flash flood forecasting, methodological problems as- sociated to the use of hydrological models for distributed flash flood forecasting with rainfall input estimated from radar.

Two-step optimization of pressure and recovery of reverse osmosis desalination process.

PubMed

Liang, Shuang; Liu, Cui; Song, Lianfa

2009-05-01

Driving pressure and recovery are two primary design variables of a reverse osmosis process that largely determine the total cost of seawater and brackish water desalination. A two-step optimization procedure was developed in this paper to determine the values of driving pressure and recovery that minimize the total cost of RO desalination. It was demonstrated that the optimal net driving pressure is solely determined by the electricity price and the membrane price index, which is a lumped parameter to collectively reflect membrane price, resistance, and service time. On the other hand, the optimal recovery is determined by the electricity price, initial osmotic pressure, and costs for pretreatment of raw water and handling of retentate. Concise equations were derived for the optimal net driving pressure and recovery. The dependences of the optimal net driving pressure and recovery on the electricity price, membrane price, and costs for raw water pretreatment and retentate handling were discussed.

Capacitive deionization coupled with microbial fuel cells to desalinate low-concentration salt water.

PubMed

Yuan, Lulu; Yang, Xufei; Liang, Peng; Wang, Lei; Huang, Zheng-Hong; Wei, Jincheng; Huang, Xia

2012-04-01

A new technology (CDI-MFC) that combined capacitive deionization (CDI) and microbial fuel cell (MFC) was developed to treat low-concentration salt water with NaCl concentration of 60mg/L. The water desalination rate was 35.6mg/(Lh), meanwhile the charge efficiency was 21.8%. Two desorption modes were investigated: discharging (DC) mode and short circuit (SC) mode. The desalination rate in the DC mode was 200.6±3.1mg/(Lh), 47.8% higher than that in the SC mode [135.7±15.3mg/(Lh)]. The average current in the DC mode was also much higher than that of the SC mode. The energy stored in the CDI cell has been reused to enhance the electron production of MFC by the discharging desorption mode (DC mode), which offers an approach to recover the electrostatic energy in the CDI cell. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of the Discharge Water which Mixed Sewage Disposal Water with Seawater Desalting Treated Sewage for Bottom Sediment and Hypoxic Water Mass

NASA Astrophysics Data System (ADS)

Watanabe, Ryoichi; Yamasaki, Koreyoshi; Minagawa, Tomoko; Iyooka, Hiroki; Kitano, Yoshinori

For every time in summer season, hypoxic water mass has formed at the inner part of Hakata Bay. Field observation study has carried out at the inner part of Hakata Bay since 2004 with the particular aim of tracking the movement of hypoxic water mass. Hypoxic water masses form the end of June to September on this area because the consumption of oxygen in bottom water layers exceeds the re-supply of oxygen from the atmosphere. Under such hypoxic conditions, the seawater desalination plant has begun to use in 2005. After seawater desalination plant operation starting, hypoxic water mass tends to improve. In this research, the authors show the following result. After seawater desalination plant has begun to operate, the hypoxia around the mixed discharge water outlet tends to be improved.

Effects of the Shuttle Orbiter fuselage and elevon on the molecular distribution of water vapor from the flash evaporator system

NASA Technical Reports Server (NTRS)

Richmond, R. G.; Kelso, R. M.

1980-01-01

A concern has arisen regarding the emissive distribution of water molecules from the shuttle orbiter flash evaporator system (FES). The role of the orbiter fuselage and elevon in affecting molecular scattering distributions was nuclear. The effect of these components were evaluated. Molecular distributions of the water vapor effluents from the FE were measured. These data were compared with analytically predicted values and the resulting implications were calculated.

The bi-directional leader observation in positive cloud-to-ground lightning flashes during summer thunderstorm season

NASA Astrophysics Data System (ADS)

Nakamura, Y.; Manabu, A.; Morimoto, T.; Ushio, T.; Kawasaki, Z.; Miki, M.; Shimizu, M.

2009-12-01

In this paper, we present observations of positive cloud-to-ground (+CG) lightning flashes obtained with the VHF BDITF (VHF Broadband Digital InTerFerometer) and the ALPS (Automatic Lightning Discharge Progressing Feature Observation System). The VHF BDITF observed two- (2D) and three-dimensional (3D) developments of lightning flashes with high time resolution. The ALPS observed the luminous propagation of the local process at low altitudes within its observational range. At 2028:59 JST on 8 August, 2008, we observed the 3D spatiotemporal development channels of +CG lightning flash with the VHF BDITF and the RS with the lightning location and protection (LLP) system. This flash is divided before and after the RS. In the former stage, the in-cloud negative breakdown (NB) progress about 15 km horizontally between 6 and 10 km high. The LLP system detects the RS near the initiation point of that negative breakdown (NB) at the end of the former stage. In the latter stage, the new NB runs through the same path as the first NB before the RS. The luminous intensity of the RS near the ground obtained with the ALPS is synchronized with the development of the new NB. The time variation of luminous intensity by the ALPS has two peaks. The time difference of these peaks is corresponding to the blank of the VHF radiation. Since the new NB following the RS runs through the path of the first NB, the positive breakdown (PB), which is not visualized by the VHF BDITF, could be considered to progress from the starting point of the first NB and touches to the ground. The RS current propagates and penetrates in the opposite direction as visualized subsequent NB. This suggests the first NB and the PB progress together. This +CG lightning flash has the bi-directional leader. To assume the path of the PB is straight line, the velocity of the PB is about 4 × 104 m/s.

Spatial interpolation of GPS PWV and meteorological variables over the west coast of Peninsular Malaysia during 2013 Klang Valley Flash Flood

NASA Astrophysics Data System (ADS)

Suparta, Wayan; Rahman, Rosnani

2016-02-01

Global Positioning System (GPS) receivers are widely installed throughout the Peninsular Malaysia, but the implementation for monitoring weather hazard system such as flash flood is still not optimal. To increase the benefit for meteorological applications, the GPS system should be installed in collocation with meteorological sensors so the precipitable water vapor (PWV) can be measured. The distribution of PWV is a key element to the Earth's climate for quantitative precipitation improvement as well as flash flood forecasts. The accuracy of this parameter depends on a large extent on the number of GPS receiver installations and meteorological sensors in the targeted area. Due to cost constraints, a spatial interpolation method is proposed to address these issues. In this paper, we investigated spatial distribution of GPS PWV and meteorological variables (surface temperature, relative humidity, and rainfall) by using thin plate spline (tps) and ordinary kriging (Krig) interpolation techniques over the Klang Valley in Peninsular Malaysia (longitude: 99.5°-102.5°E and latitude: 2.0°-6.5°N). Three flash flood cases in September, October, and December 2013 were studied. The analysis was performed using mean absolute error (MAE), root mean square error (RMSE), and coefficient of determination (R2) to determine the accuracy and reliability of the interpolation techniques. Results at different phases (pre, onset, and post) that were evaluated showed that tps interpolation technique is more accurate, reliable, and highly correlated in estimating GPS PWV and relative humidity, whereas Krig is more reliable for predicting temperature and rainfall during pre-flash flood events. During the onset of flash flood events, both methods showed good interpolation in estimating all meteorological parameters with high accuracy and reliability. The finding suggests that the proposed method of spatial interpolation techniques are capable of handling limited data sources with high accuracy, which in turn can be used to predict future floods.

Coupling flash liquid chromatography with mass spectrometry for enrichment and isolation of milk oligosaccharides for functional studies.

PubMed

Strum, John S; Aldredge, Danielle; Barile, Daniela; Lebrilla, Carlito B

2012-05-15

Mass spectrometry has been coupled with flash liquid chromatography to yield new capabilities for isolating nonchromophoric material from complicated biological mixtures. A flash liquid chromatography/tandem mass spectrometry (LC/MS/MS) method enabled fraction collection of milk oligosaccharides from biological mixtures based on composition and structure. The method is compatible with traditional gas pressure-driven flow flash chromatography widely employed in organic chemistry laboratories. The online mass detector enabled real-time optimization of chromatographic parameters to favor separation of oligosaccharides that would otherwise be indistinguishable from coeluting components with a nonspecific detector. Unlike previously described preparative LC/MS techniques, we have employed a dynamic flow connection that permits any flow rate from the flash system to be delivered from 1 to 200 ml/min without affecting the ionization conditions of the mass spectrometer. A new way of packing large amounts of graphitized carbon allowed the enrichment and separation of milligram quantities of structurally heterogeneous mixtures of human milk oligosaccharides (HMOs) and bovine milk oligosaccharides (BMOs). Abundant saccharide components in milk, such as lactose and lacto-N-tetraose, were separated from the rarer and less abundant oligosaccharides that have greater structural diversity and biological functionality. Neutral and acidic HMOs and BMOs were largely separated and enriched with a dual binary solvent system. Published by Elsevier Inc.

Modeling the Colorado Front Range Flood of 2013 with Coupled WRF and WRF-Hydro System

NASA Astrophysics Data System (ADS)

Unal, E.; Ramirez, J. A.

2015-12-01

Abstract. Flash floods are one of the most damaging natural disasters producing large socio-economic losses. Projected impacts of climate change include increases in the magnitude and the frequency of flash floods all around the world. Therefore, it is important to understand the physical processes of flash flooding to enhance our capacity for prediction, prevention, risk management, and recovery. However, understanding these processes is ambitious because of small spatial scale and sudden nature of flash floods, interactions with complex topography and land use, difficulty in defining initial soil moisture conditions, non-linearity of catchment response, and high space-time variability of storm characteristics. Thus, detailed regional case studies are needed, especially with respect to the interactions between the land surface and the atmosphere. One such flash flood event occurred recently in the Front Range of the Rocky Mountains of Colorado during September 9-15, 2013 causing 10 fatalities and $3B cost in damages. An unexpected persistent and moist weather pattern located over the mountains and produced seven-day extreme rainfall fed by moisture input from the Gulf of Mexico. We used a coupled WRF-WRF-Hydro modeling system to simulate this event for better understanding of the physical process and of the sensitivity of the hydrologic response to storm characteristics, initial soil moisture conditions, and watershed characteristics.

The saptio-temporal distribution of lightning over the southern Levant and its relation to the regional synoptic systems

NASA Astrophysics Data System (ADS)

Shalev, S.; Izsak, T.; Saaroni, H.; Yair, Y.; Ziv, B.

2010-09-01

The saptio-temporal distribution of lightning flashes over the southern Levant is derived from data obtained from the Lightning Positioning and Tracking System (LPATS) operated by the Israeli Electrical Company (IEC). The system has an aerial coverage in a range of ~ 500 Km around central Israel, including the southeastern Mediterranean Sea, Israel, Lebanon, western Syria and Jordan and the eastern part of Sinai Peninsula and the Red Sea. The study period includes 4 years. The spatial distribution of lightning flash density indicated the highest concentration over the sea, and is attributed to the contribution of sensible and latent heat fluxes. Other centers of high flash density appear along the coastal plain, expressing the friction effect of the coastline, and along orographic barriers, especially in northern Israel. The intra-annual distribution shows a complete absence of lightning in the eastern Mediterranean during the summer (JJA) which is due to the persistent existence of the subtropical high above the region. The vast majority of the lightning activity occurs during 7 months between October and April. Even though over 65% of the rainfall is obtained in the winter months (DJF) only 35% of the lightning is obtained in the winter and October is the richest month, with 40% of total annual number of lightning flashes. This is attributed mostly to tropical intrusions, i.e., Red Sea Trough (RST), which is characterized by high static instability. Cyprus lows are the synoptic system contributing the vast majority, >80%, of the rainfall in Israel, but only 42% of the lightning, whereas the RST, a minor contributor of rainfall, shares 48% of the lightning. However, during the winter 66% of the lightning flashes are associated with Cyprus lows and 25% with RST while during the autumn months the ratio is reversed: only 27% are associated with Cyprus lows and the majority (63%) occurs during RST. It was found that over 80% of the days defined as Cyprus lows were associated with lightning, indicating the instability associated with these cyclones over the region. During the RST, even though it is characterized by different weather conditions, 60% of the days were associated with lightning. The spatial distribution of lightning is further studied for positive and negative cloud-to-ground flashes separately. Positive lightning, being <10% of their total number, are concentrated eastward over the coast and inland compared to the negative flashes. This may be explained by the enhanced inclination of the thunder-cloud due to their encounter with the coastline, leading to a "tilted dipole" which is manifested in a larger percentage of positive flashes. Similar results are found in the west coast of Japan in the winter season.

Lightning Mapping With an Array of Fast Antennas

NASA Astrophysics Data System (ADS)

Wu, Ting; Wang, Daohong; Takagi, Nobuyuki

2018-04-01

Fast Antenna Lightning Mapping Array (FALMA), a low-frequency lightning mapping system comprising an array of fast antennas, was developed and established in Gifu, Japan, during the summer of 2017. Location results of two hybrid flashes and a cloud-to-ground flash comprising 11 return strokes (RSs) are described in detail in this paper. Results show that concurrent branches of stepped leaders can be readily resolved, and K changes and dart leaders with speeds up to 2.4 × 107 m/s are also well imaged. These results demonstrate that FALMA can reconstruct three-dimensional structures of lightning flashes with great details. Location accuracy of FALMA is estimated by comparing the located striking points of successive RSs in cloud-to-ground flashes. Results show that distances between successive RSs are mainly below 25 m, indicating exceptionally high location accuracy of FALMA.

Flashing light in microalgae biotechnology.

PubMed

Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

2016-03-01

Flashing light can enhance photosynthesis and improve the quality and quantity of microalgal biomass, as it can increase the products of interest by magnitudes. Therefore, the integration of flashing light effect into microalgal cultivation systems should be considered. However, microalgae require a balanced mix of the light/dark cycle for higher growth rates, and respond to light intensity differently according to the pigments acquired or lost during the growth. This review highlights recently published results on flashing light effect on microalgae and its applications in biotechnology, as well as the recently developed bioreactors designed to fulfill this effect. It also discusses how this knowledge can be applied in selecting the optimal light frequencies and intensities with specific technical properties for increasing biomass production and/or the yield of the chemicals of interest by microalgae belonging to different genera. Copyright © 2015 Elsevier Ltd. All rights reserved.

Why Flash Type Matters: A Statistical Analysis

NASA Astrophysics Data System (ADS)

Mecikalski, Retha M.; Bitzer, Phillip M.; Carey, Lawrence D.

2017-09-01

While the majority of research only differentiates between intracloud (IC) and cloud-to-ground (CG) flashes, there exists a third flash type, known as hybrid flashes. These flashes have extensive IC components as well as return strokes to ground but are misclassified as CG flashes in current flash type analyses due to the presence of a return stroke. In an effort to show that IC, CG, and hybrid flashes should be separately classified, the two-sample Kolmogorov-Smirnov (KS) test was applied to the flash sizes, flash initiation, and flash propagation altitudes for each of the three flash types. The KS test statistically showed that IC, CG, and hybrid flashes do not have the same parent distributions and thus should be separately classified. Separate classification of hybrid flashes will lead to improved lightning-related research, because unambiguously classified hybrid flashes occur on the same order of magnitude as CG flashes for multicellular storms.

Coupling ion-exchangers with inexpensive activated carbon fiber electrodes to enhance the performance of capacitive deionization cells for domestic wastewater desalination.

PubMed

Liang, Peng; Yuan, Lulu; Yang, Xufei; Zhou, Shaoji; Huang, Xia

2013-05-01

A capacitive deionization (CDI) cell was built with electrodes made of an inexpensive commercial activated carbon fiber (ACF), and then modified by incorporating ion-exchangers into the cell compartment. Three modified CDI designs were tested: MCDI - a CDI with electrodes covered by ion-exchange membranes (IEMs) of the same polarity, FCDI - a CDI with electrodes covered by ion-exchange felts (IEFs), and R-MCDI - an MCDI with cell chamber packed with ion-exchange resin (IER) granules. The cell was operated in the batch reactor mode with an initial salt concentration of 1000 mg/L NaCl, a typical level of domestic wastewater. The desalination tests involved investigations of two consecutive operation stages of CDIs: electrical adsorption (at an applied voltage of 1.2 V) and desorption [including short circuit (SC) desorption and discharge (DC) desorption]. The R-MCDI showed the highest electric adsorption as measured in the present study by desalination rate [670 ± 20 mg/(L h)] and salt removal efficiency (90 ± 1%) at 60 min, followed by the MCDI [440 ± 15 mg/(L h) and 60 ± 2%, respectively]. The superior desalination performance of the R-MCDI over other designs was also affirmed by its highest charge efficiency (110 ± 7%) and fastest desorption rates at both the SC [1960 ± 15 mg/(L·h)] and DC [3000 ± 20 mg/(L·h)] modes. The desalination rate and salt removal efficiency of the R-MCDI increased from ∼270 mg/(L h) and 83% to ∼650 mg/(L h) and 98% respectively when the applied voltage increased from 0.6 V to 1.4 V, while decreased slightly when lowering the salt water flow rate that fed into the cell. The packing of IER granules in the R-MCDI provided additional surface area for ions transfer; meanwhile, according to the results of electrochemical impedance spectroscopy (EIS) analysis, it substantially lower down the R-MCDI's ohmic resistance, resulting in improved desalination performance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Aquifer composition and the tendency toward scale-deposit formation during reverse osmosis desalination - Examples from saline ground water in New Mexico, USA

USGS Publications Warehouse

Huff, G.F.

2006-01-01

Desalination is expected to make a substantial contribution to water supply in the United States by 2020. Currently, reverse osmosis is one of the most cost effective and widely used desalination technologies. The tendency to form scale deposits during reverse osmosis is an important factor in determining the suitability of input waters for use in desalination. The tendency toward scale formation of samples of saline ground water from selected geologic units in New Mexico was assessed using simulated evaporation. All saline water samples showed a strong tendency to form CaCO3 scale deposits. Saline ground water samples from the Yeso Formation and the San Andres Limestone showed relatively stronger tendencies to form CaSO4 2H2O scale deposits and relatively weaker tendencies to form SiO2(a) scale deposits than saline ground water samples from the Rio Grande alluvium. Tendencies toward scale formation in saline ground water samples from the Dockum Group were highly variable. The tendencies toward scale formation of saline waters from the Yeso Formation, San Andres Limestone, and Rio Grande alluvium appear to correlate with the mineralogical composition of the geologic units, suggesting that scale-forming tendencies are governed by aquifer composition and water-rock interaction. ?? 2006 Elsevier B.V. All rights reserved.

Nonlinear dynamics of capacitive charging and desalination by porous electrodes.

PubMed

Biesheuvel, P M; Bazant, M Z

2010-03-01

The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by supercapacitors, water desalination and purification by capacitive deionization, and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) valid in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory for the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes with different time scales: (i) in the "supercapacitor regime" of small voltages and/or early times, the porous electrode acts like a transmission line, governed by a linear diffusion equation for the electrostatic potential, scaled to the RC time of a single pore, and (ii) in the "desalination regime" of large voltages and long times, the porous electrode slowly absorbs counterions, governed by coupled, nonlinear diffusion equations for the pore-averaged potential and salt concentration.

Nonlinear dynamics of capacitive charging and desalination by porous electrodes

NASA Astrophysics Data System (ADS)

Biesheuvel, P. M.; Bazant, M. Z.

2010-03-01

The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by supercapacitors, water desalination and purification by capacitive deionization, and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) valid in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory for the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes with different time scales: (i) in the “supercapacitor regime” of small voltages and/or early times, the porous electrode acts like a transmission line, governed by a linear diffusion equation for the electrostatic potential, scaled to the RC time of a single pore, and (ii) in the “desalination regime” of large voltages and long times, the porous electrode slowly absorbs counterions, governed by coupled, nonlinear diffusion equations for the pore-averaged potential and salt concentration.

Dendrogeomorphic analysis of flash floods in a small ungauged mountain catchment (Central Spain)

NASA Astrophysics Data System (ADS)

Ruiz-Villanueva, Virginia; Díez-Herrero, Andrés; Stoffel, Markus; Bollschweiler, Michelle; Bodoque, José M.; Ballesteros, Juan A.

2010-06-01

Flash floods represent one of the most significant natural hazards with serious death tolls and economic damage at a worldwide level in general and in Mediterranean mountain catchments in particular. In these environments, systematic data is often lacking and analyses have to be based on alternative approaches such as dendrogeomorphology. In this study, we focus on the identification of flash floods based on growth disturbances (GD) observed in 98 heavily affected Mediterranean pine trees ( Pinus pinaster Ait.) located in or next to the torrential channel of the Pelayo River in the Spanish Central System. Flash floods are quite common in this catchment and are triggered by heavy storms, with high discharge and debris transport rates favoured by high stream gradients. Comparison of the anomalies in tree morphology and the position of the trees in the channel showed that the intensity of the disturbance clearly depends on geomorphology. The dating of past flash flood events was based on the number and intensity of GD observed in the tree-ring series and on the spatial distribution of affected trees along the torrent, thus allowing seven flash flood events during the last 50 years to be dated, namely in 1963, 1966, 1973, 1976, 1996, 2000, and 2005.

Dendrogeomorphic analysis of Flash Floods in a small ungauged mountain catchment (Central Spain)

NASA Astrophysics Data System (ADS)

Ruiz-Villanueva, Virginia; Díez-Herrero, Andrés.; Stoffel, Markus; Bollschweiler, Michelle; María Bodoque, José; Ballesteros, Juan Antonio

2010-05-01

Flash floods represent one of the most significant natural hazards with serious death tolls and economic damage at a worldwide level in general and in Mediterranean mountain catchments in particular. In these environments, systematic data is often lacking and analyses have to be based on alternative approaches such as dendrogeomorphology. In this study, we focus on the identification of flash floods based on growth disturbances (GD) observed in 98 heavily affected Mediterranean pine trees (Pinus pinaster Ait.) located in or next to the torrential channel of the Pelayo River in the Spanish Central System. Flash floods are quite common in this catchment and are triggered by heavy storms, with high discharge and debris transport rates favoured by high stream gradients. Comparison of the anomalies in tree morphology and the position of the trees in the channel showed that the intensity of the disturbance clearly depends on geomorphology. The dating of past flash-flood events was based on the number and intensity of GD observed in the tree-ring series, and on the spatial distribution of affected trees along the torrent, thus allowing seven flash-flood events during the last ~50 years to be dated, namely in 1963, 1966, 1973, 1976, 1996, 2000, and 2005.

FlaME: Flash Molecular Editor - a 2D structure input tool for the web

PubMed Central

2011-01-01

Background So far, there have been no Flash-based web tools available for chemical structure input. The authors herein present a feasibility study, aiming at the development of a compact and easy-to-use 2D structure editor, using Adobe's Flash technology and its programming language, ActionScript. As a reference model application from the Java world, we selected the Java Molecular Editor (JME). In this feasibility study, we made an attempt to realize a subset of JME's functionality in the Flash Molecular Editor (FlaME) utility. These basic capabilities are: structure input, editing and depiction of single molecules, data import and export in molfile format. Implementation The result of molecular diagram sketching in FlaME is accessible in V2000 molfile format. By integrating the molecular editor into a web page, its communication with the HTML elements on this page is established using the two JavaScript functions, getMol() and setMol(). In addition, structures can be copied to the system clipboard. Conclusion A first attempt was made to create a compact single-file application for 2D molecular structure input/editing on the web, based on Flash technology. With the application examples presented in this article, it could be demonstrated that the Flash methods are principally well-suited to provide the requisite communication between the Flash object (application) and the HTML elements on a web page, using JavaScript functions. PMID:21284863

Nanotechnology: A Policy Primer

DTIC Science & Technology

2010-06-02

States of 24 million barrels of oil.3 • Universal access to clean water. Nanotechnology water desalination and filtration systems may offer...CRS Report for Congress Prepared for Members and Committees of Congress Nanotechnology : A Policy Primer John F. Sargent Jr. Specialist...00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Nanotechnology : A Policy Primer 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

Nanotechnology: A Policy Primer

DTIC Science & Technology

2008-05-20

of oil.3 ! Universal access to clean water. Nanotechnology water desalination and filtration systems may offer affordable, scalable, and portable...Order Code RL34511 Nanotechnology : A Policy Primer May 20, 2008 John F. Sargent Specialist in Science and Technology Policy Resources, Science, and...REPORT DATE 20 MAY 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Nanotechnology : A Policy Primer 5a

The energy balance within a bubble column evaporator

NASA Astrophysics Data System (ADS)

Fan, Chao; Shahid, Muhammad; Pashley, Richard M.

2018-05-01

Bubble column evaporator (BCE) systems have been studied and developed for many applications, such as thermal desalination, sterilization, evaporative cooling and controlled precipitation. The heat supplied from warm/hot dry bubbles is to vaporize the water in various salt solutions until the solution temperature reaches steady state, which was derived into the energy balance of the BCE. The energy balance and utilization involved in each BCE process form the fundamental theory of these applications. More importantly, it opened a new field for the thermodynamics study in the form of heat and vapor transfer in the bubbles. In this paper, the originally derived energy balance was reviewed on the basis of its physics in the BCE process and compared with new proposed energy balance equations in terms of obtained the enthalpy of vaporization (Δ H vap) values of salt solutions from BCE experiments. Based on the analysis of derivation and Δ H vap values comparison, it is demonstrated that the original balance equation has high accuracy and precision, within 2% over 19-55 °C using improved systems. Also, the experimental and theoretical techniques used for determining Δ H vap values of salt solutions were reviewed for the operation conditions and their accuracies compared to the literature data. The BCE method, as one of the most simple and accurate techniques, offers a novel way to determine Δ H vap values of salt solutions based on its energy balance equation, which had error less than 3%. The thermal energy required to heat the inlet gas, the energy used for water evaporation in the BCE and the energy conserved from water vapor condensation were estimated in an overall energy balance analysis. The good agreement observed between input and potential vapor condensation energy illustrates the efficiency of the BCE system. Typical energy consumption levels for thermal desalination for producing pure water using the BCE process was also analyzed for different inlet air temperatures, and indicated the better energy efficiency, of 7.55 kW·h per m3 of pure water, compared to traditional thermal desalination techniques.

Heavy Rain, Flash Flooding Possible Across Parts of Lower Mississippi Valley, Southeast

NASA Image and Video Library

2017-12-08

The system that brought heavy rainfall and flash flooding to parts of the southern Plains and western Gulf Coast over the past several days continues to push eastward, with the greatest potential for heavy rain and flash flooding on Monday across parts of the lower Mississippi Valley and Southeast. This image was taken by GOES East at 1515Z on October 26, 2015. Credit: NOAA/NASA GOES Project Credit: NASA/NOAA via NOAA Environmental Visualization Laboratory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

A non-ideal model for predicting the effect of dissolved salt on the flash point of solvent mixtures.

PubMed

Liaw, Horng-Jang; Wang, Tzu-Ai

2007-03-06

Flash point is one of the major quantities used to characterize the fire and explosion hazard of liquids. Herein, a liquid with dissolved salt is presented in a salt-distillation process for separating close-boiling or azeotropic systems. The addition of salts to a liquid may reduce fire and explosion hazard. In this study, we have modified a previously proposed model for predicting the flash point of miscible mixtures to extend its application to solvent/salt mixtures. This modified model was verified by comparison with the experimental data for organic solvent/salt and aqueous-organic solvent/salt mixtures to confirm its efficacy in terms of prediction of the flash points of these mixtures. The experimental results confirm marked increases in liquid flash point increment with addition of inorganic salts relative to supplementation with equivalent quantities of water. Based on this evidence, it appears reasonable to suggest potential application for the model in assessment of the fire and explosion hazard for solvent/salt mixtures and, further, that addition of inorganic salts may prove useful for hazard reduction in flammable liquids.

Optical bullet-tracking algorithms for weapon localization in urban environments

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

Roberts, R S; Breitfeller, E F

2006-03-31

Localization of the sources of small-arms fire, mortars, and rocket propelled grenades is an important problem in urban combat. Weapons of this type produce characteristic signatures, such as muzzle flashes, that are visible in the infrared. Indeed, several systems have been developed that exploit the infrared signature of muzzle flash to locate the positions of shooters. However, systems based on muzzle flash alone can have difficulty localizing weapons if the muzzle flash is obscured or suppressed. Moreover, optical clutter can be problematic to systems that rely on muzzle flash alone. Lawrence Livermore National Laboratory (LLNL) has developed a projectile trackingmore » system that detects and localizes sources of small-arms fire, mortars and similar weapons using the thermal signature of the projectile rather than a muzzle flash. The thermal signature of a projectile, caused by friction as the projectile travels along its trajectory, cannot be concealed and is easily discriminated from optical clutter. The LLNL system was recently demonstrated at the MOUT facility of the Aberdeen Test Center [1]. In the live-fire demonstration, shooters armed with a variety of small-arms, including M-16s, AK-47s, handguns, mortars and rockets, were arranged at several positions in around the facility. Experiments ranged from a single-weapon firing a single-shot to simultaneous fire of all weapons on full automatic. The LLNL projectile tracking system was demonstrated to localize multiple shooters at ranges up to 400m, far greater than previous demonstrations. Furthermore, the system was shown to be immune to optical clutter that is typical in urban combat. This paper describes the image processing and localization algorithms designed to exploit the thermal signature of projectiles for shooter localization. The paper begins with a description of the image processing that extracts projectile information from a sequence of infrared images. Key to the processing is an adaptive spatio-temporal filter developed to suppress scene clutter. The filtered image sequence is further processed to produce a set of parameterized regions, which are classified using several discriminate functions. Regions that are classified as projectiles are passed to a data association algorithm that matches features from these regions with existing tracks, or initializes new tracks as needed. A Kalman filter is used to smooth and extrapolate existing tracks. Shooter locations are determined by solving a combinatorial least-squares solution for all bullet tracks. It also provides an error ellipse for each shooter, quantifying the uncertainty of shooter location. The paper concludes with examples from the live-fire exercise at the Aberdeen Test Center.« less

Multispectral signature analysis measurements of selected sniper rifles and small arms

NASA Astrophysics Data System (ADS)

Law, David B.; Carapezza, Edward M.; Csanadi, Christina J.; Edwards, Gerald D.; Hintz, Todd M.; Tong, Ronald M.

1997-02-01

During October 1995 - June 1996, the Naval Command, Control and Ocean Surveillance Center RDT&E Division (NRaD), under sponsorship from Defense Advanced Research Projects Agency (DARPA), conducted an intensive series of multi-spectral signature analyses of typical sniper weapons. Multi-spectral signatures of the muzzle flashes from rifles and pistols and some imagery of the bullets in flight were collected. Multi- spectral signatures of the muzzle flash were collected in the infrared (2.5 - 14.5 microns), visible -- near-IR (400 - 1200 nanometers), and the ultra-violet (185 - 400 nanometers) wavelength regions. These measurements consisted of high spectral resolution (0.0159 micron) measurements of the spectral radiance of the muzzle flash. A time history plot of the muzzle flash as it evolves just forward of the end of the muzzle is provided. These measurements were performed with a CI Systems Model SR5000 IR/Visible spectroradiometer and an Ocean Optics Model PC1000 UV spectroradiometer. Muzzle flash infrared imagery is provided to show the effect that specific muzzle breaks have on the resulting muzzle flash. The following set of sniper weapons were included in this test: AK-47, SKS, M16A2, M-14, FN-FAL, SMLE IIa, 03 Springfield, SVD Dragunov, 50 caliber McMillan, and a 45 caliber ACP pistol. The results of this signature analysis show that important measurable electro-optical differences do exist between all these weapons in terms of spectral radiance of the flash, spectral content of the gun powders, and spectral shapes/geometries of the muzzle flashes. These differences were sufficient such that, after a more complete data base is collected, it will be possible to develop a passive electro-optical weapon and ammunition identifier.

Hydrologic ensembles based on convection-permitting precipitation nowcasts for flash flood warnings

NASA Astrophysics Data System (ADS)

Demargne, Julie; Javelle, Pierre; Organde, Didier; de Saint Aubin, Céline; Ramos, Maria-Helena

2017-04-01

In order to better anticipate flash flood events and provide timely warnings to communities at risk, the French national service in charge of flood forecasting (SCHAPI) is implementing a national flash flood warning system for small-to-medium ungauged basins. Based on a discharge-threshold flood warning method called AIGA (Javelle et al. 2014), the current version of the system runs a simplified hourly distributed hydrologic model with operational radar-gauge QPE grids from Météo-France at a 1-km2 resolution every 15 minutes. This produces real-time peak discharge estimates along the river network, which are subsequently compared to regionalized flood frequency estimates to provide warnings according to the AIGA-estimated return period of the ongoing event. To further extend the effective warning lead time while accounting for hydrometeorological uncertainties, the flash flood warning system is being enhanced to include Météo-France's AROME-NWC high-resolution precipitation nowcasts as time-lagged ensembles and multiple sets of hydrological regionalized parameters. The operational deterministic precipitation forecasts, from the nowcasting version of the AROME convection-permitting model (Auger et al. 2015), were provided at a 2.5-km resolution for a 6-hr forecast horizon for 9 significant rain events from September 2014 to June 2016. The time-lagged approach is a practical choice of accounting for the atmospheric forecast uncertainty when no extensive forecast archive is available for statistical modelling. The evaluation on 781 French basins showed significant improvements in terms of flash flood event detection and effective warning lead-time, compared to warnings from the current AIGA setup (without any future precipitation). We also discuss how to effectively communicate verification information to help determine decision-relevant warning thresholds for flood magnitude and probability. Javelle, P., Demargne, J., Defrance, D., Arnaud, P., 2014. Evaluating flash flood warnings at ungauged locations using post-event surveys: a case study with the AIGA warning system. Hydrological Sciences Journal, doi: 10.1080/02626667.2014.923970 Auger, L., Dupont, O., Hagelin, S., Brousseau, P., Brovelli, P., 2015. AROME-NWC: a new nowcasting tool based on an operational mesoscale forecasting system. Quarterly Journal of the Royal Meteorological Society, 141: 1603-1611, doi:10.1002/qj.2463

A Study on Cost Allocation in Nuclear Power Coupled with Desalination

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

Lee, ManKi; Kim, SeungSu; Moon, KeeHwan

As for a single-purpose desalination plant, there is no particular difficulty in computing the unit cost of the water, which is obtained by dividing the annual total costs by the output of fresh water. When it comes to a dual-purpose plant, cost allocation is needed between the two products. No cost allocation is needed in some cases where two alternatives producing the same water and electricity output are to be compared. In these cases, the consideration of the total cost is then sufficient. This study assumes MED (Multi-Effect Distillation) technology is adopted when nuclear power is coupled with desalination. Themore » total production cost of the two commodities in dual-purpose plant can easily be obtained by using costing methods, if the necessary raw data are available. However, it is not easy to calculate a separate cost for each product, because high-pressure steam plant costs cannot be allocated to one or the other without adopting arbitrary methods. Investigation on power credit method is carried out focusing on the cost allocation of combined benefits due to dual production, electricity and water. The illustrative calculation is taken from Preliminary Economic Feasibility Study of Nuclear Desalination in Madura Island, Indonesia. The study is being performed by BATAN (National Nuclear Energy Agency), KAERI (Korean Atomic Energy Research Institute) and under support of the IAEA (International Atomic Energy Agency) started in the year 2002 in order to perform a preliminary economic feasibility in providing the Madurese with sufficient power and potable water for the public and to support industrialization and tourism in Madura Region. The SMART reactor coupled with MED is considered to be an option to produce electricity and potable water. This study indicates that the correct recognition of combined benefits attributable to dual production is important in carrying out economics of desalination coupled with nuclear power. (authors)« less

Bacterial community structure and variation in a full-scale seawater desalination plant for drinking water production.

PubMed

Belila, A; El-Chakhtoura, J; Otaibi, N; Muyzer, G; Gonzalez-Gil, G; Saikaly, P E; van Loosdrecht, M C M; Vrouwenvelder, J S

2016-05-01

Microbial processes inevitably play a role in membrane-based desalination plants, mainly recognized as membrane biofouling. We assessed the bacterial community structure and diversity during different treatment steps in a full-scale seawater desalination plant producing 40,000 m(3)/d of drinking water. Water samples were taken over the full treatment train consisting of chlorination, spruce media and cartridge filters, de-chlorination, first and second pass reverse osmosis (RO) membranes and final chlorine dosage for drinking water distribution. The water samples were analyzed for water quality parameters (total bacterial cell number, total organic carbon, conductivity, pH, etc.) and microbial community composition by 16S rRNA gene pyrosequencing. The planktonic microbial community was dominated by Proteobacteria (48.6%) followed by Bacteroidetes (15%), Firmicutes (9.3%) and Cyanobacteria (4.9%). During the pretreatment step, the spruce media filter did not impact the bacterial community composition dominated by Proteobacteria. In contrast, the RO and final chlorination treatment steps reduced the Proteobacterial relative abundance in the produced water where Firmicutes constituted the most dominant bacterial group. Shannon and Chao1 diversity indices showed that bacterial species richness and diversity decreased during the seawater desalination process. The two-stage RO filtration strongly reduced the water conductivity (>99%), TOC concentration (98.5%) and total bacterial cell number (>99%), albeit some bacterial DNA was found in the water after RO filtration. About 0.25% of the total bacterial operational taxonomic units (OTUs) were present in all stages of the desalination plant: the seawater, the RO permeates and the chlorinated drinking water, suggesting that these bacterial strains can survive in different environments such as high/low salt concentration and with/without residual disinfectant. These bacterial strains were not caused by contamination during water sample filtration or from DNA extraction protocols. Control measurements for sample contamination are important for clean water studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Variability of lightning activity over India on ENSO time scales

NASA Astrophysics Data System (ADS)

Ahmad, Adnan; Ghosh, Mili

2017-12-01

ENSO, the reliable indicator of inter-annual climate variation of the ocean-atmosphere system in the tropical Pacific region, can affect the overall lightning activity which is another atmospheric phenomenon. In the present study, the impact of the ENSO on the total lightning activity over India has been studied for the period 2004-2014. During the El-Nino period (July 2004-April 2005 and July 2009-April 2010), total number of lightning flashes increased by 10% and 18% respectively and during La-Nina period (July 2010-April 2011 and August 2011 to March 2012), the total number of lightning flashes decreased approximately by 19% and 28% respectively as compared to the mean of corresponding period (2004-14) of the Non-ENSO. Seasonal variation of flash density is also examined for the El-Nino and La-Nina period. The result shows that in the El-Nino period of the pre-monsoon and monsoon seasons, there is an increment in the flash density approximately by 48% and 9% respectively than the Non-ENSO and the spatial variation also having high flash density along the foot of Himalayas region. In the post-monsoon season, there is a marginal change in the flash density between El-Nino and the Non-ENSO. In the winter season, there is an increment in flash density in the El-Nino period approximately by 45% than the Non-ENSO. In the La-Nina period of the pre-monsoon and monsoon seasons, there is the decrement in the flash density approximately by the 44% and 24% respectively than the Non-ENSO. In the Post-monsoon season and winter season of La-Nina, the flash density is increased by about 24% and 33% over India. These findings can be applied to do proper planning of lightning induced hazard mitigation as lightning is of one of the major natural disasters of India.

Economic assessment of flash co-pyrolysis of short rotation coppice and biopolymer waste streams.

PubMed

Kuppens, T; Cornelissen, T; Carleer, R; Yperman, J; Schreurs, S; Jans, M; Thewys, T

2010-12-01

The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass and waste of biopolymers synergistically improves the characteristics of the pyrolysis process: e.g. reduction of the water content of the bio-oil, more bio-oil and less char production and an increase of the HHV of the oil. This research paper investigates the economic consequences of the synergistic effects of flash co-pyrolysis of 1:1 w/w ratio blends of willow and different biopolymer waste streams via cost-benefit analysis and Monte Carlo simulations taking into account uncertainties. In all cases economic opportunities of flash co-pyrolysis of biomass with biopolymer waste are improved compared to flash pyrolysis of pure willow. Of all the biopolymers under investigation, polyhydroxybutyrate (PHB) is the most promising, followed by Eastar, Biopearls, potato starch, polylactic acid (PLA), corn starch and Solanyl in order of decreasing profits. Taking into account uncertainties, flash co-pyrolysis is expected to be cheaper than composting biopolymer waste streams, except for corn starch. If uncertainty increases, composting also becomes more interesting than flash co-pyrolysis for waste of Solanyl. If the investment expenditure is 15% higher in practice than estimated, the preference for flash co-pyrolysis compared to composting biopolymer waste becomes less clear. Only when the system of green current certificates is dismissed, composting clearly is a much cheaper processing technique for disposing of biopolymer waste. Copyright © 2010 Elsevier Ltd. All rights reserved.

Gabapentin for hot flashes in 420 women with breast cancer: a randomised double-blind placebo-controlled trial

PubMed Central

Pandya, K J; Morrow, G R; Roscoe, J A; Hickok, J T; Zhao, H; Pajon, E; Sweeney, T J; Banerjee, T K; Flynn, P J

2005-01-01

Summary Background Most women receiving systemic therapy for breast cancer experience hot flashes. We undertook a randomised, double-blind, placebo-controlled, multi-institutional trial to assess the efficacy of gabapentin in controlling hot flashes in women with breast cancer. Methods 420 women with breast cancer who were having two or more hot flashes per day were randomly assigned placebo, gabapentin 300 mg/day, or gabapentin 900 mg/day by mouth in three divided doses for 8 weeks. Each patient kept a 1-week, self-report diary on the frequency, severity, and duration of hot flashes before the start of the study and during weeks 4 and 8 of treatment. Analyses were by intention to treat. Findings Evaluable data were available on 371 participants at 4 weeks (119 placebo, 123 gabapentin 300 mg, and 129 gabapentin 900 mg) and 347 at 8 weeks (113 placebo, 114 gabapentin 300 mg, and 120 gabapentin 900 mg). The percentage decreases in hot-flash severity score between baseline and weeks 4 and 8, respectively were: 21% (95% CI 12 to 30) and 15% (1 to 29) in the placebo group; 33% (23 to 43) and 31% (16 to 46) in the group assigned gabapentin 300 mg; and 49% (42 to 56) and 46% (34 to 58) in the group assigned gabapentin 900 mg. The differences between the groups were significant (p=0.0001 at 4 weeks and p=0.007 at 8 weeks by ANCOVA for overall treatment effect, adjusted for baseline values); only the higher dose of gabapentin was associated with significant decreases in hot-flash frequency and severity. Interpretation Gabapentin is effective in the control of hot flashes at a dose of 900 mg/day, but not at a dose of 300 mg/day. This drug should be considered for treatment of hot flashes in women with breast cancer. PMID:16139656

LOFAR Lightning Imaging: Mapping Lightning With Nanosecond Precision

NASA Astrophysics Data System (ADS)

Hare, B. M.; Scholten, O.; Bonardi, A.; Buitink, S.; Corstanje, A.; Ebert, U.; Falcke, H.; Hörandel, J. R.; Leijnse, H.; Mitra, P.; Mulrey, K.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Rutjes, C.; Schellart, P.; Thoudam, S.; Trinh, T. N. G.; ter Veen, S.; Winchen, T.

2018-03-01

Lightning mapping technology has proven instrumental in understanding lightning. In this work we present a pipeline that can use lightning observed by the LOw-Frequency ARray (LOFAR) radio telescope to construct a 3-D map of the flash. We show that LOFAR has unparalleled precision, on the order of meters, even for lightning flashes that are over 20 km outside the area enclosed by LOFAR antennas (˜3,200 km2), and can potentially locate over 10,000 sources per lightning flash. We also show that LOFAR is the first lightning mapping system that is sensitive to the spatial structure of the electrical current during individual lightning leader steps.

Observations of Stratiform Lightning Flashes and Their Microphysical and Kinematic Environments

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Williams, Earle

2016-01-01

During the Midlatitude Continental Convective Clouds Experiment (MC3E), combined observations of clouds and precipitation were made from airborne and ground-based in situ and remote sensing platforms. These observations were coordinated for multiple mesoscale convective systems (MCSs) that passed over the MC3E domain in northern Oklahoma. Notably, during a storm on 20 May 2011 in situ and remote sensing airborne observations were made near the times and locations of stratiform positive cloud-to-ground (+CG) lightning flashes. These +CGs resulted from extremely large stratiform lightning flashes that were hundreds of km in length and lasted several seconds. This dataset provides an unprecedented look at kinematic and microphysical environments in the vicinity of large, powerful, and long-lived stratiform lightning flashes. We will use this dataset to understand the influence of low liquid water contents (LWCs) in the electrical charging of MCS stratiform regions.

Observations of Stratiform Lightning Flashes and Their Microphysical and Kinematic Environments

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Williams, Earle

2017-01-01

During the Midlatitude Continental Convective Clouds Experiment (MC3E), combined observations of clouds and precipitation were made from airborne and ground-based in situ and remote sensing platforms. These observations were coordinated for multiple mesoscale convective systems (MCSs) that passed over the MC3E domain in northern Oklahoma. Notably, during a storm on 20 May 2011 in situ and remote sensing airborne observations were made near the times and locations of stratiform positive cloud-to-ground (+CG) lightning flashes. These +CGs resulted from extremely large stratiform lightning flashes that were hundreds of km in length and lasted several seconds. This dataset provides an unprecedented look at kinematic and microphysical environments in the vicinity of large, powerful, and long-lived stratiform lightning flashes. We will use this dataset to understand the influence of low liquid water contents (LWCs) in the electrical charging of MCS stratiform regions.

RF radiation from lightning

NASA Technical Reports Server (NTRS)

Levine, D. M.

1978-01-01

Radiation from lightning in the RF band from 3-300 MHz were monitored. Radiation in this frequency range is of interest as a potential vehicle for monitoring severe storms and for studying the lightning itself. Simultaneous measurements were made of RF radiation and fast and slow field changes. Continuous analogue recordings with a system having 300 kHz of bandwidth were made together with digital records of selected events (principally return strokes) at greater temporal resolution. The data reveal patterns in the RF radiation for the entire flash which are characteristic of flash type and independent of the frequency of observation. Individual events within the flash also have characteristic RF patterns. Strong radiation occurs during the first return strokes, but delayed about 20 micron sec with respect to the begining of the return stroke; whereas, RF radiation from subsequent return strokes tends to be associated with cloud processes preceding the flash with comparatively little radiation occurring during the return stroke itself.

Flash LIDAR Emulator for HIL Simulation

NASA Technical Reports Server (NTRS)

Brewster, Paul F.

2010-01-01

NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project is building a system for detecting hazards and automatically landing controlled vehicles safely anywhere on the Moon. The Flash Light Detection And Ranging (LIDAR) sensor is used to create on-the-fly a 3D map of the unknown terrain for hazard detection. As part of the ALHAT project, a hardware-in-the-loop (HIL) simulation testbed was developed to test the data processing, guidance, and navigation algorithms in real-time to prove their feasibility for flight. Replacing the Flash LIDAR camera with an emulator in the testbed provided a cheaper, safer, more feasible way to test the algorithms in a controlled environment. This emulator must have the same hardware interfaces as the LIDAR camera, have the same performance characteristics, and produce images similar in quality to the camera. This presentation describes the issues involved and the techniques used to create a real-time flash LIDAR emulator to support HIL simulation.

An investigation of air solubility in Jet A fuel at high pressures

NASA Technical Reports Server (NTRS)

Faeth, G. M.

1981-01-01

Problems concerned with the supercritical injection concept are discussed. Supercritical injection involves dissolving air into a fuel prior to injection. A similar effect is obtained by preheating the fuel so that a portion of the fuel flashes when its pressure is reduced. Flashing improves atomization properties and the presence of air in the primary zone of a spray flame reduces the formation of pollutants. The investigation is divided into three phases: (1) measure the solubility and density properties of fuel/gas mixtures, including Jet A/air, at pressures and correlate these results using theory; (2) investigate the atomization properties of flashing liquids, including fuel/dissolved gas systems. Determine and correlate the effect of inlet properties and injector geometry on mass flow rates, Sauter mean diameter and spray angles; (3) examine the combustion properties of flashing injection in an open burner flame, considering flame shape and soot production.

Microsecond-scale electric field pulses in cloud lightning discharges

NASA Technical Reports Server (NTRS)

Villanueva, Y.; Rakov, V. A.; Uman, M. A.; Brook, M.

1994-01-01

From wideband electric field records acquired using a 12-bit digitizing system with a 500-ns sampling interval, microsecond-scale pulses in different stages of cloud flashes in Florida and New Mexico are analyzed. Pulse occurrence statistics and waveshape characteristics are presented. The larger pulses tend to occur early in the flash, confirming the results of Bils et al. (1988) and in contrast with the three-stage representation of cloud-discharge electric fields suggested by Kitagawa and Brook (1960). Possible explanations for the discrepancy are discussed. The tendency for the larger pulses to occur early in the cloud flash suggests that they are related to the initial in-cloud channel formation processes and contradicts the common view found in the atmospheric radio-noise literature that the main sources of VLF/LF electromagnetic radiation in cloud flashes are the K processes which occur in the final, or J type, part of the cloud discharge.

A LIS Validation Study at the KSC-ER using LDAR and Field Mill Data

NASA Technical Reports Server (NTRS)

Koshak, William J.; Christian, Hugh J.; Krider, E. Philip

1999-01-01

The chance of having the TRMM satellite pass over east central Florida when there is lightning over the NASA Kennedy Space Center (KSC) and USAF Eastern Range (ER) is small; however, such a condition did occur on September 21, 1998 (Day 264). Starting at about 20:40 GMT, the Lightning Imaging Sensor (LIS) reported 5 flashes during a 90 second interval that the KSC-ER was within the sensor field of view. Ground-based instrumentation, the Lightning Detection and Ranging (LDAR) system and a network of electric field mills (FM), detected 6 flashes in the same interval. In this paper, we will compare the times and locations of the optical pulses that were detected by LIS with the times and locations of RF sources (LDAR) and the charges that were deposited by the flash (FM network). We will show that LIS responded to all flashes that the LDAR and FM network detected; however, two discharges that were separated by less than 1 second in time and by about 10 km in space were grouped as one flash by the LIS data processing algorithm. In spite of the fact that all flashes occurred near the edge of the LIS field of view, the locations of the LIS events were consistent with both the LDAR and FM locations (the latter are usually within 1-2 kilometers of each other and often are co-located). Two of the 5 flashes reported by LIS were shifted north by about 8 km from the corresponding LDAR and FM locations. The LIS flash times tended to be after the first LDAR pulse was detected and before the last, and the integrated light signal (per LIS event) was surprisingly constant over the 5 flashes that were detected by LIS. In the future, we plan to study more correlated events and will try to determine whether and how the LIS light signal is related to the charge transfer in the flash and/or the number and spatial extent of RF sources.

Portable flash lamp reflectance analyzer system and method

NASA Technical Reports Server (NTRS)

Kalshoven, James Edward (Inventor)

1999-01-01

The system and method allow spectroscopic analysis of vegetation or the like without effects from changing sun and cloud conditions, undesired portions of the area of interest or atmospheric disturbances. The system (1) includes a light source (5) such as a xenon flash lamp, a telescope (7), a spectrometer (9), an analog/digital converter (11), a memory (13), a display (15), and an on-board microprocessor (17) or a port (19) for attachment to a laptop computer. The system is taken to an area of interest in the woods (step 41), the vegetation is illuminated from below (step 43) and data are taken (step 45).

Global Positioning System Synchronized Active Light Autonomous Docking System

NASA Technical Reports Server (NTRS)

Howard, Richard T. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor); Bell, Joseph L. (Inventor)

1996-01-01

A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprising at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

Global Positioning System Synchronized Active Light Autonomous Docking System

NASA Technical Reports Server (NTRS)

Howard, Richard (Inventor)

1994-01-01

A Global Positioning System Synchronized Active Light Autonomous Docking System (GPSSALADS) for automatically docking a chase vehicle with a target vehicle comprises at least one active light emitting target which is operatively attached to the target vehicle. The target includes a three-dimensional array of concomitantly flashing lights which flash at a controlled common frequency. The GPSSALADS further comprises a visual tracking sensor operatively attached to the chase vehicle for detecting and tracking the target vehicle. Its performance is synchronized with the flash frequency of the lights by a synchronization means which is comprised of first and second internal clocks operatively connected to the active light target and visual tracking sensor, respectively, for providing timing control signals thereto, respectively. The synchronization means further includes first and second Global Positioning System receivers operatively connected to the first and second internal clocks, respectively, for repeatedly providing simultaneous synchronization pulses to the internal clocks, respectively. In addition, the GPSSALADS includes a docking process controller means which is operatively attached to the chase vehicle and is responsive to the visual tracking sensor for producing commands for the guidance and propulsion system of the chase vehicle.

3D flash lidar performance in flight testing on the Morpheus autonomous, rocket-propelled lander to a lunar-like hazard field

NASA Astrophysics Data System (ADS)

Roback, Vincent E.; Amzajerdian, Farzin; Bulyshev, Alexander E.; Brewster, Paul F.; Barnes, Bruce W.

2016-05-01

For the first time, a 3-D imaging Flash Lidar instrument has been used in flight to scan a lunar-like hazard field, build a 3-D Digital Elevation Map (DEM), identify a safe landing site, and, in concert with an experimental Guidance, Navigation, and Control system, help to guide the Morpheus autonomous, rocket-propelled, free-flying lander to that safe site on the hazard field. The flight tests served as the TRL 6 demo of the Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT) system and included launch from NASA-Kennedy, a lunar-like descent trajectory from an altitude of 250m, and landing on a lunar-like hazard field of rocks, craters, hazardous slopes, and safe sites 400m down-range. The ALHAT project developed a system capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The Flash Lidar is a second generation, compact, real-time, air-cooled instrument. Based upon extensive on-ground characterization at flight ranges, the Flash Lidar was shown to be capable of imaging hazards from a slant range of 1 km with an 8 cm range precision and a range accuracy better than 35 cm, both at 1-σ. The Flash Lidar identified landing hazards as small as 30 cm from the maximum slant range which Morpheus could achieve (450 m); however, under certain wind conditions it was susceptible to scintillation arising from air heated by the rocket engine and to pre-triggering on a dust cloud created during launch and transported down-range by wind.

3-D Flash Lidar Performance in Flight Testing on the Morpheus Autonomous, Rocket-Propelled Lander to a Lunar-Like Hazard Field

NASA Technical Reports Server (NTRS)

Roback, Vincent E.; Amzajerdian, Farzin; Bulyshev, Alexander E.; Brewster, Paul F.; Barnes, Bruce W.

2016-01-01

For the first time, a 3-D imaging Flash Lidar instrument has been used in flight to scan a lunar-like hazard field, build a 3-D Digital Elevation Map (DEM), identify a safe landing site, and, in concert with an experimental Guidance, Navigation, and Control (GN&C) system, help to guide the Morpheus autonomous, rocket-propelled, free-flying lander to that safe site on the hazard field. The flight tests served as the TRL 6 demo of the Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT) system and included launch from NASA-Kennedy, a lunar-like descent trajectory from an altitude of 250m, and landing on a lunar-like hazard field of rocks, craters, hazardous slopes, and safe sites 400m down-range. The ALHAT project developed a system capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The Flash Lidar is a second generation, compact, real-time, air-cooled instrument. Based upon extensive on-ground characterization at flight ranges, the Flash Lidar was shown to be capable of imaging hazards from a slant range of 1 km with an 8 cm range precision and a range accuracy better than 35 cm, both at 1-delta. The Flash Lidar identified landing hazards as small as 30 cm from the maximum slant range which Morpheus could achieve (450 m); however, under certain wind conditions it was susceptible to scintillation arising from air heated by the rocket engine and to pre-triggering on a dust cloud created during launch and transported down-range by wind.

The Thermal Flash Protection System, low pass filter JN175666A1

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

Washington, L.A.

1987-06-01

This report discusses the development of the JN175666A1 Low Pass Filter used in the B1-B Thermal Flash Protection System. It also discusses problems encountered during development of the ceramic capacitors and how they were resolved. Included in this report is a description of the filter, the electrical and environmental tests, why they were performed and data accumulated during the development testing. After completing the evaluation of this device, it is concluded that the JN175666A1 filter is a usable component for the B1-B system.

Novel Cleanup Agents Designed Exclusively for Oil Field Membrane Filtration Systems Low Cost Field Demonstrations of Cleanup Agents in Controlled Experimental Environments

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

David Burnett; Harold Vance

2007-08-31

The goal of our project is to develop innovative processes and novel cleaning agents for water treatment facilities designed to remove fouling materials and restore micro-filter and reverse osmosis (RO) membrane performance. This project is part of Texas A&M University's comprehensive study of the treatment and reuse of oilfield brine for beneficial purposes. Before waste water can be used for any beneficial purpose, it must be processed to remove contaminants, including oily wastes such as residual petroleum hydrocarbons. An effective way of removing petroleum from brines is the use of membrane filters to separate oily waste from the brine. Texasmore » A&M and its partners have developed highly efficient membrane treatment and RO desalination for waste water including oil field produced water. We have also developed novel and new cleaning agents for membrane filters utilizing environmentally friendly materials so that the water from the treatment process will meet U.S. EPA drinking water standards. Prototype micellar cleaning agents perform better and use less clean water than alternate systems. While not yet optimized, the new system restores essentially complete membrane flux and separation efficiency after cleaning. Significantly the amount of desalinated water that is required to clean the membranes is reduced by more than 75%.« less

Optical countermeasures against CLOS weapon systems

NASA Astrophysics Data System (ADS)

Toet, Alexander; Benoist, Koen W.; van Lingen, Joost N. J.; Schleijpen, H. Ric M. A.

2013-10-01

There are many weapon systems in which a human operator acquires a target, tracks it and designates it. Optical countermeasures against this type of systems deny the operator the possibility to fulfill this visual task. We describe the different effects that result from stimulation of the human visual system with high intensity (visible) light, and the associated potential operational impact. Of practical use are flash blindness, where an intense flash of light produces a temporary "blind-spot" in (part of) the visual field, flicker distraction, where strong intensity and/or color changes at a discomfortable frequency are produced, and disability glare where a source of light leads to contrast reduction. Hence there are three possibilities to disrupt the visual task of an operator with optical countermeasures such as flares or lasers or a combination of these; namely, by an intense flash of light, by an annoying light flicker or by a glare source. A variety of flares for this purpose is now available or under development: high intensity flash flares, continuous burning flares or strobe flares which have an oscillating intensity. The use of flare arrays seems particularly promising as an optical countermeasure. Lasers are particularly suited to interfere with human vision, because they can easily be varied in intensity, color and size, but they have to be directed at the (human) target, and issues like pointing and eye-safety have to be taken into account. Here we discuss the design issues and the operational impact of optical countermeasures against human operators.

Lightning characteristics of derecho producing mesoscale convective systems

NASA Astrophysics Data System (ADS)

Bentley, Mace L.; Franks, John R.; Suranovic, Katelyn R.; Barbachem, Brent; Cannon, Declan; Cooper, Stonie R.

2016-06-01

Derechos, or widespread, convectively induced wind storms, are a common warm season phenomenon in the Central and Eastern United States. These damaging and severe weather events are known to sweep quickly across large spatial regions of more than 400 km and produce wind speeds exceeding 121 km h-1. Although extensive research concerning derechos and their parent mesoscale convective systems already exists, there have been few investigations of the spatial and temporal distribution of associated cloud-to-ground lightning with these events. This study analyzes twenty warm season (May through August) derecho events between 2003 and 2013 in an effort to discern their lightning characteristics. Data used in the study included cloud-to-ground flash data derived from the National Lightning Detection Network, WSR-88D imagery from the University Corporation for Atmospheric Research, and damaging wind report data obtained from the Storm Prediction Center. A spatial and temporal analysis was conducted by incorporating these data into a geographic information system to determine the distribution and lightning characteristics of the environments of derecho producing mesoscale convective systems. Primary foci of this research include: (1) finding the approximate size of the lightning activity region for individual and combined event(s); (2) determining the intensity of each event by examining the density and polarity of lightning flashes; (3) locating areas of highest lightning flash density; and (4) to provide a lightning spatial analysis that outlines the temporal and spatial distribution of flash activity for particularly strong derecho producing thunderstorm episodes.

Muzzle flash localization for the dismounted soldier

NASA Astrophysics Data System (ADS)

Kennedy Scott, Will

2015-05-01

The ability to accurately and rapidly know the precise location of enemy fire would be a substantial capability enhancement to the dismounted soldier. Acoustic gun-shot detections systems can provide an approximate bearing but it is desired to precisely know the location (direction and range) of enemy fire; for example to know from `which window' the fire is coming from. Funded by the UK MOD (via Roke Manor Research) QinetiQ is developing an imaging solution built around an InGaAs camera. This paper presents work that QinetiQ has undertaken on the Muzzle Flash Locator system. Key technical challenges that have been overcome are explained and discussed in this paper. They include; the design of the optical sensor and processing hardware to meet low size, weight and power requirements; the algorithm approach required to maintain sensitivity whilst rejecting false alarms from sources such as close passing insects and sun glint from scene objects; and operation on the move. This work shows that such a sensor can provide sufficient sensitivity to detect muzzle flash events to militarily significant ranges and that such a system can be combined with an acoustic gunshot detection system to minimize the false alarm rate. The muzzle flash sensor developed in this work operates in real-time and has a field of view of approximately 29° (horizontal) by 12° (vertical) with a pixel resolution of 0.13°. The work has demonstrated that extension to a sensor with realistic angular rotation rate is feasible.

Total Lightning as a Severe Weather Diagnostic in Strongly Baroclinic Systems in Central Florida

NASA Technical Reports Server (NTRS)

Williams, E.; Boldi, B.; Matlin, A.; Weber, M.; Hodanish, S.; Sharp, D.; Goodman, Steven J.; Raghavan, R.; Buechler, Dennis

1998-01-01

The establishment of a consistent behavior of total lightning activity in severe convective storms has been challenged historically by the relative scarcity of these storms combined with the difficulties inherent in documenting the (dominant) intracloud component of total lightning. This situation has changed recently with the abundance of severe weather in central Florida during 1997-98, including the tornado outbreak of February 23, 1998, and with the development of the operational LISDAD system (Boldi et al, this conference) to document these cases. This paper is concerned primarily with the behavior of total lightning in severe weather during the dry season when the Florida atmosphere is most strongly baroclinic. It has been found that all three manifestations of severe weather (ie., hall, wind, tornadoes) are consistently preceded by rapid increases in total flash rate with values often in excess of 100 flashes/minute. Preliminary analysis suggests that this systematic electrical behavior observed in summertime 'pulse severe' storms (Hodanish et al, this conference) also pertains to the more strongly baroclinic, long-track tornadic storms (more common in Oklahoma), as evidenced by the February 23, 1998 outbreak case in central Florida exhibiting two long-tracking F3 tornadoes. The largest flash rates in severe weather anywhere occur in baroclinic conditions at midlatitude. The physical plausibility of flash rates in excess of 100 per minute will be assessed. We will also consider the differences in storm structure for high flash rate storms that are non-severe.

Measuring hot flash phenomenonology using ambulatory prospective digital diaries

PubMed Central

Fisher, William I.; Thurston, Rebecca C.

2016-01-01

Objective This study provides the description, protocol, and results from a novel prospective ambulatory digital hot flash phenomenon diary. Methods This study included 152 midlife women with daily hot flashes who completed an ambulatory electronic hot flash diary continuously for the waking hours of 3 consecutive days. In this diary, women recorded their hot flashes and accompanying characteristics and associations as the hot flashes occurred. Results Self-reported hot flash severity on the digital diaries indicated that the majority of hot flashes were rated as mild (41.3%) or moderate (43.7%). Severe (13.1%) and very severe (1.8%) hot flashes were less common. Hot flash bother ratings were rated as mild (43%), or moderate (33.5%), with fewer hot flashes reported bothersome (17.5%) or very bothersome (6%). The majority of hot flashes were reported as occurring on the on the face (78.9%), neck (74.7%), and chest (61.3%). Prickly skin was reported concurrently with 32% of hot flashes, 7% with anxiety and 5% with nausea. A novel finding, 38% of hot flashes were accompanied by a premonitory aura. Conclusion A prospective electronic digital hot flash diary allows for a more precise quantitation of hot flashes while overcoming many of the limitations of commonly employed retrospective questionnaires and paper diaries. Unique insights into the phenomenology, loci and associated characteristics of hot flashes were obtained using this device. The digital hot flash phenomenology diary is recommended for future ambulatory studies of hot flashes as a prospective measure of the hot flash experience. PMID:27404030

Measuring hot flash phenomenonology using ambulatory prospective digital diaries.

PubMed

Fisher, William I; Thurston, Rebecca C

2016-11-01

This study provides the description, protocol, and results from a novel prospective ambulatory digital hot flash phenomenon diary. This study included 152 midlife women with daily hot flashes who completed an ambulatory electronic hot flash diary continuously for the waking hours of three consecutive days. In this diary, women recorded their hot flashes and accompanying characteristics and associations as the hot flashes occurred. Self-reported hot flash severity on the digital diaries indicated that the majority of hot flashes were rated as mild (41.3%) or moderate (43.7%). Severe (13.1%) and very severe (1.8%) hot flashes were less common. Hot flash bother ratings were rated as mild (43%), or moderate (33.5%), with fewer hot flashes reported bothersome (17.5%) or very bothersome (6%). The majority of hot flashes were reported as occurring on the face (78.9%), neck (74.7%), and chest (61.3%). Of all reported hot flashes, 32% occurred concurrently with prickly skin, 7% with anxiety, and 5% with nausea. A novel finding from the study was that 38% of hot flashes were accompanied by a premonitory aura. A prospective electronic digital hot flash diary allows for a more precise quantitation of hot flashes while overcoming many of the limitations of commonly used retrospective questionnaires and paper diaries. Unique insights into the phenomenology, loci, and associated characteristics of hot flashes were obtained using this device. The digital hot flash phenomenology diary is recommended for future ambulatory studies of hot flashes as a prospective measure of the hot flash experience.

An experimental operative system for shallow landslide and flash flood warning based on rainfall thresholds and soil moisture modelling

NASA Astrophysics Data System (ADS)

Brigandı, G.; Aronica, G. T.; Basile, G.; Pasotti, L.; Panebianco, M.

2012-04-01

On November 2011 a thunderstorms became almost exceptional over the North-East part of the Sicily Region (Italy) producing local heavy rainfall, mud-debris flow and flash flooding. The storm was concentrated on the Tyrrhenian sea coast near the city of Barcellona within the Longano catchment. Main focus of the paper is to present an experimental operative system for alerting extreme hydrometeorological events by using a methodology based on the combined use of rainfall thresholds, soil moisture indexes and quantitative precipitation forecasting. As matter of fact, shallow landslide and flash flood warning is a key element to improve the Civil Protection achievements to mitigate damages and safeguard the security of people. It is a rather complicated task, particularly in those catchments with flashy response where even brief anticipations are important and welcomed. It is well known how the triggering of shallow landslides is strongly influenced by the initial soil moisture conditions of catchments. Therefore, the early warning system here applied is based on the combined use of rainfall thresholds, derived both for flash flood and for landslide, and soil moisture conditions; the system is composed of several basic component related to antecedent soil moisture conditions, real-time rainfall monitoring and antecedent rainfall. Soil moisture conditions were estimated using an Antecedent Precipitation Index (API), similar to this widely used for defining soil moisture conditions via Antecedent Moisture conditions index AMC. Rainfall threshold for landslides were derived using historical and statistical analysis. Finally, rainfall thresholds for flash flooding were derived using an Instantaneous Unit Hydrograph based lumped rainfall-runoff model with the SCS-CN routine for net rainfall. After the implementation and calibration of the model, a testing phase was carried out by using real data collected for the November 2001 event in the Longano catchment. Moreover, in order to test the capability of the system to forecast thise event, Quantitative Precipitation Forecasting provided by the SILAM (Sicily Limited Area Model), a meteorological model run by SIAS (Sicilian Agrometeorological Service) with a forecast horizon up to 144 hours, have been used to run the system.

The Use of Water Vapor for Detecting Environments that Lead to Convectively Produced Heavy Precipitation and Flash Floods

NASA Technical Reports Server (NTRS)

Scofield, Rod; Vicente, Gilberto; Hodges, Mike

2000-01-01

This Tech Report summarizes years of study and experiences on using GOES Water vapor (6.7 micron and precipitable water) and Special Sensor Microwave Imager (SSM/1) from the Defense Meteorological Satellite Program (DMSP) derived Precipitable Water (PNAI) for detecting environments favorable for convectively produced flash floods. An emphasis is on the moisture. upper air flow, and equivalent potential temperature (Theta(sub e)) patterns that lead to devastating flood events. The 15 minute 6.7 micron water vapor imagery is essential for tracking middle to upper tropospheric disturbances that produce upward vertical motion and initiate flash flood producing systems. Water vapor imagery at 6.7 micron is also used to detect surges of upper level moisture (called tropical water vapor plumes) that have been associated with extremely heavy rainfall. Since the water vapor readily depicts lifting mechanisms and upper level moisture, water vapor imagery is often an excellent source of data for recognizing patterns of heavy precipitation and flash floods. In order to analyze the depth of the moisture, the PW aspects of the troposphere must be measured. The collocation (or nearby location) of high values ofP\\V and instability are antecedent conditions prior to the flash flood or heavy rainfall events. Knowledge of PW magnitudes have been used as thresholds for impending flash flood events, PW trends are essential in flash flood prediction. Conceptual models and water vapor products are used to study some of the characteristics of convective systems that occurred over the United States of America (USA) during the summer of 1997 and the 1997-1998 El Nino. P\\V plumes were associated with most of the \\vest coast heavy precipitation events examined during the winter season of 1997 - 1998, In another study, conducted during the summer season of 1997. results showed that the collocation of water vapor (6.7 micron) and P\\N' plumes possessed higher correlations with predicted rainfall amounts than when PW plumes occurred by themselves (i.e.. without the presence of 6.7 micron water vapor plumes). Satellite Analysis Branch (SAB) meteorologists use the 6.7 micron water and P\\V products for their QPE's (interactive Flash Flood Analyzer (IFFA) and Auto-Estimator precipitation estimates), Outlooks, and heavy precipitation briefings with the Hydrometeorological Prediction Center/National Center for Environmental Prediction.

Removal efficiency of nickel and lead from industrial wastewater using microbial desalination cell

NASA Astrophysics Data System (ADS)

Mirzaienia, Fariba; Asadipour, Ali; Jafari, Ahmad Jonidi; Malakootian, Mohammad

2017-11-01

Microbial desalination cell (MDC) is a new method of desalination. Its energy is supplied through microbial metabolism of organic materials. In this study, synthetic samples were provided with concentration of 25, 50, 75, 100 mg/L Ni and Pb. Removal efficiency of each metal was analyzed after 60, 90, 120 min, psychrophilic, mesophilic, thermophilic and 3-4, 4-5, 5-6 mg/L dissolved oxygen. Optimum conditions for removing Ni and Pb were achieved in 100, 4.5 and 4.6 mg/L dissolved oxygen, respectively, 26 °C and 120 min. Nickel and led were removed from wastewaters of Isfahan electroplating industry and steel company. The maximum removal efficiencies of Ni and Pb in real samples were 68.81 and 70.04%. MDC can be considered as a good choice for removing Ni and Pb from industrial wastewater. Due to microorganisms for decomposing organic material in municipal wastewater, metals from industrial wastewater can be removed simultaneously.

The Role of Ion Exchange Membranes in Membrane Capacitive Deionisation.

PubMed

Hassanvand, Armineh; Wei, Kajia; Talebi, Sahar; Chen, George Q; Kentish, Sandra E

2017-09-14

Ion-exchange membranes (IEMs) are unique in combining the electrochemical properties of ion exchange resins and the permeability of a membrane. They are being used widely to treat industrial effluents, and in seawater and brackish water desalination. Membrane Capacitive Deionisation (MCDI) is an emerging, energy efficient technology for brackish water desalination in which these ion-exchange membranes act as selective gates allowing the transport of counter-ions toward carbon electrodes. This article provides a summary of recent developments in the preparation, characterization, and performance of ion exchange membranes in the MCDI field. In some parts of this review, the most relevant literature in the area of electrodialysis (ED) is also discussed to better elucidate the role of the ion exchange membranes. We conclude that more work is required to better define the desalination performance of the proposed novel materials and cell designs for MCDI in treating a wide range of feed waters. The extent of fouling, the development of cleaning strategies, and further techno-economic studies, will add value to this emerging technique.

Yeast fuel cell: Application for desalination

NASA Astrophysics Data System (ADS)

Mardiana, Ummy; Innocent, Christophe; Cretin, Marc; Buchari, Buchari; Gandasasmita, Suryo

2016-02-01

Yeasts have been implicated in microbial fuel cells as biocatalysts because they are non-pathogenic organisms, easily handled and robust with a good tolerance in different environmental conditions. Here we investigated baker's yeast Saccharomyces cerevisiae through the oxidation of glucose. Yeast was used in the anolyte, to transfer electrons to the anode in the presence of methylene blue as mediator whereas K3Fe(CN)6 was used as an electron acceptor for the reduction reaction in the catholyte. Power production with biofuel cell was coupled with a desalination process. The maximum current density produced by the cell was 88 mA.m-2. In those conditions, it was found that concentration of salt was removed 64% from initial 0.6 M after 1-month operation. This result proves that yeast fuel cells can be used to remove salt through electrically driven membrane processes and demonstrated that could be applied for energy production and desalination. Further developments are in progress to improve power output to make yeast fuel cells applicable for water treatment.

Enhancement in ion adsorption rate and desalination efficiency in a capacitive deionization cell through improved electric field distribution using electrodes composed of activated carbon cloth coated with zinc oxide nanorods.

PubMed

Laxman, Karthik; Myint, Myo Tay Zar; Bourdoucen, Hadj; Dutta, Joydeep

2014-07-09

Electrodes composed of activated carbon cloth (ACC) coated with zinc oxide (ZnO) nanorods are compared with plain ACC electrodes, with respect to their desalination efficiency of a 17 mM NaCl solution at different applied potentials. Polarization of the ZnO nanorods increased the penetration depth and strength of the electric field between the electrodes, leading to an increase in the capacitance and charge efficiency at reduced input charge ratios. Uniform distribution of the electric field lines between two electrodes coated with ZnO nanorods led to faster ion adsorption rates, reduced the electrode saturation time, and increased the average desalination efficiency by ∼45% for all applied potentials. The electrodes were characterized for active surface area, capacitance from cyclic voltammetry, theoretical assessment of surface area utilization, and the magnitude of electric field force acting on an ion of unit charge for each potential.

Electroadsorption Desalination with Carbon Nanotube/PAN-Based Carbon Fiber Felt Composites as Electrodes

PubMed Central

Liu, Yang; Zhou, Junbo

2014-01-01

The chemical vapor deposition method is used to prepare CNT (carbon nanotube)/PCF (PAN-based carbon fiber felt) composite electrodes in this paper, with the surface morphology of CNT/PCF composites and electroadsorption desalination performance being studied. Results show such electrode materials with three-dimensional network nanostructures having a larger specific surface area and narrower micropore distribution, with a huge number of reactive groups covering the surface. Compared with PCF electrodes, CNT/PCF can allow for a higher adsorption and desorption rate but lower energy consumption; meanwhile, under the condition of the same voltage change, the CNT/PCF electrodes are provided with a better desalination effect. The study also found that the higher the original concentration of the solution, the greater the adsorption capacity and the lower the adsorption rate. At the same time, the higher the solution's pH, the better the desalting; the smaller the ions' radius, the greater the amount of adsorption. PMID:24963504

HybridICE® filter: ice separation in freeze desalination of mine waste waters.

PubMed

Adeniyi, A; Maree, J P; Mbaya, R K K; Popoola, A P I; Mtombeni, T; Zvinowanda, C M

2014-01-01

Freeze desalination is an alternative method for the treatment of mine waste waters. HybridICE(®) technology is a freeze desalination process which generates ice slurry in surface scraper heat exchangers that use R404a as the primary refrigerant. Ice separation from the slurry takes place in the HybridICE filter, a cylindrical unit with a centrally mounted filter element. Principally, the filter module achieves separation of the ice through buoyancy force in a continuous process. The HybridICE filter is a new and economical means of separating ice from the slurry and requires no washing of ice with water. The performance of the filter at a flow-rate of 25 L/min was evaluated over time and with varied evaporating temperature of the refrigerant. Behaviours of the ice fraction and residence time were also investigated. The objective was to find ways to improve the performance of the filter. Results showed that filter performance can be improved by controlling the refrigerant evaporating temperature and eliminating overflow.

Wastewater reclamation using discarded reverse osmosis membranes for reuse in irrigation in Djibouti, an arid country.

PubMed

Awaleh, Mohamed Osman; Ahmed, Moussa Mahdi; Soubaneh, Youssouf Djibril; Hoch, Farhan Bouraleh; Bouh, Samatar Mohamed; Dirieh, Elias Said

2013-01-01

The purpose of this paper is to establish the feasibility of recovering discarded reverse osmosis (RO) membranes in order to reduce the salinity of domestic treated wastewater. This study shows that the reuse of RO membranes is of particular interest for arid countries having naturally high mineralized water such as Djibouti. The pilot desalination unit reduces the electrical conductivity, the turbidity and the total dissolved salt respectively at 75-85, 96.7 and 95.4%. The water produced with this desalination unit contains an average of 254 cfu/100 mL total coliforms and 87 cfu/100 mL fecal coliforms. This effluent meets the World Health Organization standards for treated wastewater reuse for agricultural purposes. The annual cost of the desalination unit was evaluated as US $/m(3) 0.82, indicating the relatively high cost of this process. Nevertheless, such processes are required to produce an effluent, with a high reuse potential.

High-flux water desalination with interfacial salt sieving effect in nanoporous carbon composite membranes

NASA Astrophysics Data System (ADS)

Chen, Wei; Chen, Shuyu; Liang, Tengfei; Zhang, Qiang; Fan, Zhongli; Yin, Hang; Huang, Kuo-Wei; Zhang, Xixiang; Lai, Zhiping; Sheng, Ping

2018-04-01

Freshwater flux and energy consumption are two important benchmarks for the membrane desalination process. Here, we show that nanoporous carbon composite membranes, which comprise a layer of porous carbon fibre structures grown on a porous ceramic substrate, can exhibit 100% desalination and a freshwater flux that is 3-20 times higher than existing polymeric membranes. Thermal accounting experiments demonstrated that the carbon composite membrane saved over 80% of the latent heat consumption. Theoretical calculations combined with molecular dynamics simulations revealed the unique microscopic process occurring in the membrane. When the salt solution is stopped at the openings to the nanoscale porous channels and forms a meniscus, the vapour can rapidly transport across the nanoscale gap to condense on the permeate side. This process is driven by the chemical potential gradient and aided by the unique smoothness of the carbon surface. The high thermal conductivity of the carbon composite membrane ensures that most of the latent heat is recovered.

Cultivation of Arthrospira (spirulina) platensis in desalinator wastewater and salinated synthetic medium: protein content and amino-acid profile

PubMed Central

Volkmann, Harriet; Imianovsky, Ulisses; Oliveira, Jorge L.B.; Sant’Anna, Ernani S.

2008-01-01

Arthrospira (Spirulina) platensis was cultivated in laboratory under controlled conditions (30°C, photoperiod of 12 hours light/dark provided by fluorescent lamps at a light intensity of 140 μmol photons.m-2.s-1 and constant bubbling air) in three different culture media: (1) Paoletti medium (control), (2) Paoletti supplemented with 1 g.L-1 NaCl (salinated water) and (3) Paoletti medium prepared with desalinator wastewater. The effects of these treatments on growth, protein content and amino acid profile were measured. Maximum cell concentrations observed in Paoletti medium, Paoletti supplemented with salinated water or with desalinator wastewater were 2.587, 3.545 and 4.954 g.L-1, respectively. Biomass in medium 3 presented the highest protein content (56.17%), while biomass in medium 2 presented 48.59% protein. All essential amino acids, except lysine and tryptophan, were found in concentrations higher than those requiried by FAO. PMID:24031187

Bioremediation of steel plant wastewater and enhanced electricity generation in microbial desalination cell.

PubMed

Shinde, Omkar A; Bansal, Ankita; Banerjee, Angela; Sarkar, Supriya

2018-05-01

Microbial desalination cell (MDC) is a propitious technology towards water desalination by utilizing wastewater as an energy source. In this study, a multi-chambered MDC was used to bioremediate steel plant wastewater using the same wastewater as a fuel for anodic bacteria. A pure culture of Pseudomonas putida MTCC 1194 was isolated and inoculated to remove toxic phenol. Three different inoculum conditions, namely P. putida (INC-A), a mixture of P. putida and activated sludge (INC-B), and activated sludge alone (INC-C) were employed in an anodic chamber to mainly compare the electricity generation and phenol degradation in MDCs. The study revealed the maximum phenol removal of 82 ± 2.4%, total dissolved solids (TDS) removal of 68 ± 1.5%, and power generation of 10.2 mW/m 2 using INC-B. The synergistic interactions between microorganisms, can enhance the toxic phenol degradation and also electricity generation in MDC for onsite wastewater application.

Local Contributors and Predictability of Flash Drought at the Marena Oklahoma In Situ Sensor Testbed (MOISST) During 2012

NASA Astrophysics Data System (ADS)

Basara, J. B.; Otkin, J.; Mahan, H. R.; Anderson, M. C.; Hain, C.; Wagle, P.; Xiao, X.

2014-12-01

The Marena Oklahoma In Situ Sensor Testbed (MOISST) site was installed in May 2010 as part of the calibration and validation program for the NASA Soil Moisture Active Passive (SMAP) mission. The site includes more than 200 soil, vegetation, and atmospheric sensors installed over an approximately 64 hectare pasture in Central Oklahoma with 4 main stations and multiple sensors installed in profiles. Additional sensors located at the site include a COsmic-ray Soil Moisture Observing System, global position system reflectometers, a passive distributed temperature system, an eddy correlation flux tower, and a phenocam. During 2012, flash drought conditions occurred at the MOISST location as conditions transitioned from no drought in late April to D4 (exceptional drought) in mid August. The array of instruments captured the dramatic transition of land-surface conditions at the MOISST site, in particular during a period spanning approximately six weeks in July and August in whereby drought conditions changed from abnormally dry to exceptional drought and ecosystem collapsed occurred. Results for the analyses demonstrated that both soil moisture and vegetation dynamics were critical components to flash drought development. Further, when the Evaporative Stress Index (ESI) was applied to the MOISST site during 2012, the results demonstrated that the predictability of drought conditions were increased to nearly six weeks prior to flash drought development that began in July.

Extrafoveally applied flashing light affects contrast thresholds of achromatic and S-cone isolating, but not L-M cone modulated stimuli.

PubMed

Őze, A; Puszta, A; Buzás, P; Kóbor, P; Braunitzer, G; Nagy, A

2018-06-21

Flashing light stimulation is often used to investigate the visual system. However, the magnitude of the effect of this stimulus on the various subcortical pathways is not well investigated. The signals of conscious vision are conveyed by the magnocellular, parvocellular and koniocellular pathways. Parvocellular and koniocellular pathways (or more precisely, the L-M opponent and S-cone isolating channels) can be accessed by isoluminant red-green (L-M) and S-cone isolating stimuli, respectively. The main goal of the present study was to explore how costimulation with strong white extrafoveal light flashes alters the perception of stimuli specific to these pathways. Eleven healthy volunteers with negative neurological and ophthalmological history were enrolled for the study. Isoluminance of L-M and S-cone isolating sine-wave gratings was set individually, using the minimum motion procedure. The contrast thresholds for these stimuli as well as for achromatic gratings were determined by an adaptive staircase procedure where subjects had to indicate the orientation (horizontal, oblique or vertical) of the gratings. Thresholds were then determined again while a strong white peripheral light flash was presented 50 ms before each trial. Peripheral light flashes significantly (p < 0.05) increased the contrast thresholds of the achromatic and S-cone isolating stimuli. The threshold elevation was especially marked in case of the achromatic stimuli. However, the contrast threshold for the L-M stimuli was not significantly influenced by the light flashes. We conclude that extrafoveally applied light flashes influence predominantly the perception of achromatic stimuli. Copyright © 2018 Elsevier B.V. All rights reserved.

Observations of Two Sprite-Producing Storms in Colorado

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Lyons, Walter A.; Cummer, Steven A.; Fuchs, Brody R.; Dolan, Brenda; Rutledge, Steven A.; Krehbiel, Paul; Rison, William; Stanley, Mark; Ashcraft, Thomas

2016-01-01

Two sprite-producing thunderstorms were observed on 8 and 25 June 2012 in northeastern Colorado by a combination of low-light cameras, a lightning mapping array, polarimetric and Doppler radars, the National Lightning Detection Network, and charge moment change measurements. The 8 June event evolved from a tornadic hailstorm to a larger multicellular system that produced 21 observed positive sprites in 2 h. The majority of sprites occurred during a lull in convective strength, as measured by total flash rate, flash energy, and radar echo volume. Mean flash area spiked multiple times during this period; however, total flash rates still exceeded 60 min(sup 1), and portions of the storm featured a complex anomalous charge structure, with midlevel positive charge near 20degC. The storm produced predominantly positive cloud-to-ground lightning. All sprite-parent flashes occurred on the northeastern flank of the storm, where strong westerly upper level flow was consistent with advection of charged precipitation away from convection, providing a pathway for stratiform lightning. The 25 June event was another multicellular hailstorm with an anomalous charge structure that produced 26 positive sprites in less than 1 h. The sprites again occurred during a convective lull, with relatively weaker reflectivity and lower total flash rate but relatively larger mean flash area. However, all sprite parents occurred in or near convection and tapped charge layers in adjacent anvil cloud. The results demonstrate the sprite production by convective ground strokes in anomalously charged storms and also indicate that sprite production and convective vigor are inversely related in mature storms.

Time Correlations of Lightning Flash Sequences in Thunderstorms Revealed by Fractal Analysis

NASA Astrophysics Data System (ADS)

Gou, Xueqiang; Chen, Mingli; Zhang, Guangshu

2018-01-01

By using the data of lightning detection and ranging system at the Kennedy Space Center, the temporal fractal and correlation of interevent time series of lightning flash sequences in thunderstorms have been investigated with Allan factor (AF), Fano factor (FF), and detrended fluctuation analysis (DFA) methods. AF, FF, and DFA methods are powerful tools to detect the time-scaling structures and correlations in point processes. Totally 40 thunderstorms with distinguishing features of a single-cell storm and apparent increase and decrease in the total flash rate were selected for the analysis. It is found that the time-scaling exponents for AF (αAF) and FF (αFF) analyses are 1.62 and 0.95 in average, respectively, indicating a strong time correlation of the lightning flash sequences. DFA analysis shows that there is a crossover phenomenon—a crossover timescale (τc) ranging from 54 to 195 s with an average of 114 s. The occurrence of a lightning flash in a thunderstorm behaves randomly at timescales <τc but shows strong time correlation at scales >τc. Physically, these may imply that the establishment of an extensive strong electric field necessary for the occurrence of a lightning flash needs a timescale >τc, which behaves strongly time correlated. But the initiation of a lightning flash within a well-established extensive strong electric field may involve the heterogeneities of the electric field at a timescale <τc, which behave randomly.

Two-Dimensional Porous Electrode Model for Capacitive Deionization

DOE PAGES

Hemmatifar, Ali; Stadermann, Michael; Santiago, Juan G.

2015-10-28

Here, ion transport in porous conductive materials is of great importance in a variety of electrochemical systems including batteries and supercapacitors. We here analyze the coupling of flow and charge transport and charge capacitance in capacitive deionization (CDI). In CDI, a pair of porous carbon electrodes is employed to electrostatically retain and remove ionic species from aqueous solutions. We here develop and solve a novel unsteady two-dimensional model for capturing the ion adsorption/desorption dynamics in a flow-between CDI system. We use this model to study the complex, nonlinear coupling between electromigration, diffusion, and advection of ions. We also fabricated amore » laboratory-scale CDI cell which we use to measure the near-equilibrium, cumulative adsorbed salt, and electric charge as a function of applied external voltage. We use these integral measures to validate and calibrate this model. We further present a detailed computational study of the spatiotemporal adsorption/desorption dynamics under constant voltage and constant flow conditions. We show results for low (20 mM KCl) and relatively high (200 mM KCl) inlet ion concentrations and identify effects of ion starvation on desalination. We show that in both cases electromigrative transport eventually becomes negligible and diffusive ion transport reduces the desalination rate.« less

Graphene-Based Standalone Solar Energy Converter for Water Desalination and Purification.

PubMed

Yang, Yang; Zhao, Ruiqi; Zhang, Tengfei; Zhao, Kai; Xiao, Peishuang; Ma, Yanfeng; Ajayan, Pulickel M; Shi, Gaoquan; Chen, Yongsheng

2018-01-23

Harvesting solar energy for desalination and sewage treatment has been considered as a promising solution to produce clean water. However, state-of-the-art technologies often require optical concentrators and complicated systems with multiple components, leading to poor efficiency and high cost. Here, we demonstrate an extremely simple and standalone solar energy converter consisting of only an as-prepared 3D cross-linked honeycomb graphene foam material without any other supporting components. This simple all-in-one material can act as an ideal solar thermal converter capable of capturing and converting sunlight into heat, which in turn can distill water from various water sources into steam and produce purified water under ambient conditions and low solar flux with very high efficiency. High specific water production rate of 2.6 kg h -1 m -2 g -1 was achieved with near ∼87% under 1 sun intensity and >80% efficiency even under ambient sunlight (<1 sun). This scalable sheet-like material was used to obtain pure drinkable water from both seawater and sewage water under ambient conditions. Our results demonstrate a competent monolithic material platform providing a paradigm change in water purification by using a simple, point of use, reusable, and low-cost solar thermal water purification system for a variety of environmental conditions.

A computational assessment of the permeability and salt rejection of carbon nanotube membranes and their application to water desalination

PubMed Central

Thomas, Michael; Corry, Ben

2016-01-01

Membranes made from nanomaterials such as nanotubes and graphene have been suggested to have a range of applications in water filtration and desalination, but determining their suitability for these purposes requires an accurate assessment of the properties of these novel materials. In this study, we use molecular dynamics simulations to determine the permeability and salt rejection capabilities for membranes incorporating carbon nanotubes (CNTs) at a range of pore sizes, pressures and concentrations. We include the influence of osmotic gradients and concentration build up and simulate at realistic pressures to improve the reliability of estimated membrane transport properties. We find that salt rejection is highly dependent on the applied hydrostatic pressure, meaning high rejection can be achieved with wider tubes than previously thought; while membrane permeability depends on salt concentration. The ideal size of the CNTs for desalination applications yielding high permeability and high salt rejection is found to be around 1.1 nm diameter. While there are limited energy gains to be achieved in using ultra-permeable CNT membranes in desalination by reverse osmosis, such membranes may allow for smaller plants to be built as is required when size or weight must be minimized. There are diminishing returns in further increasing membrane permeability, so efforts should focus on the fabrication of membranes containing narrow or functionalized CNTs that yield the desired rejection or selection properties rather than trying to optimize pore densities. PMID:26712639

Composition and Variability of Biofouling Organisms in Seawater Reverse Osmosis Desalination Plants ▿ †

PubMed Central

Zhang, Minglu; Jiang, Sunny; Tanuwidjaja, Dian; Voutchkov, Nikolay; Hoek, Eric M. V.; Cai, Baoli

2011-01-01

Seawater reverse osmosis (SWRO) membrane biofouling remains a common challenge in the desalination industry, but the marine bacterial community that causes membrane fouling is poorly understood. Microbial communities at different stages of treatment processes (intake, cartridge filtration, and SWRO) of a desalination pilot plant were examined by both culture-based and culture-independent approaches. Bacterial isolates were identified to match the genera Shewanella, Alteromonas, Vibrio, and Cellulophaga based on 16S rRNA gene sequencing analysis. The 16S rRNA gene clone library of the SWRO membrane biofilm showed that a filamentous bacterium, Leucothrix mucor, which belongs to the gammaproteobacteria, accounted for nearly 30% of the clone library, while the rest of the microorganisms (61.2% of the total clones) were related to the alphaproteobacteria. 16S rRNA gene terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that bacteria colonizing the SWRO membrane represented a subportion of microbes in the source seawater; however, they were quite different from those colonizing the cartridge filter. The examination of five SWRO membranes from desalination plants located in different parts of the world showed that although the bacterial communities from the membranes were not identical to each other, some dominant bacteria were commonly observed. In contrast, bacterial communities in source seawater were significantly different based on location and season. Microbial profiles from 14 cartridge filters collected from different plants also revealed spatial trends. PMID:21551282

Enhanced desalination performance of membrane capacitive deionization cells by packing the flow chamber with granular activated carbon.

PubMed

Bian, Yanhong; Yang, Xufei; Liang, Peng; Jiang, Yong; Zhang, Changyong; Huang, Xia

2015-11-15

A new design of membrane capacitive deionization (MCDI) cell was constructed by packing the cell's flow chamber with granular activated carbon (GAC). The GAC packed-MCDI (GAC-MCDI) delivered higher (1.2-2.5 times) desalination rates than the regular MCDI at all test NaCl concentrations (∼ 100-1000 mg/L). The greatest performance enhancement by packed GAC was observed when treating saline water with an initial NaCl concentration of 100 mg/L. Several different GAC materials were tested and they all exhibited similar enhancement effects. Comparatively, packing the MCDI's flow chamber with glass beads (GB; non-conductive) and graphite granules (GG; conductive but with lower specific surface area than GAC) resulted in inferior desalination performance. Electrochemical impedance spectroscopy (EIS) analysis showed that the GAC-MCDI had considerably smaller internal resistance than the regular MCDI (∼ 19.2 ± 1.2 Ω versus ∼ 1222 ± 15 Ω at 100 mg/L NaCl). The packed GAC also decreased the ionic resistance across the flow chamber (∼ 1.49 ± 0.05 Ω versus ∼ 1130 ± 12 Ω at 100 mg/L NaCl). The electric double layer (EDL) formed on the GAC surface was considered to store salt ions during electrosorption, and facilitate the ion transport in the flow chamber because of the higher ion conductivity in the EDLs than in the bulk solution, thereby enhancing the MCDI's desalination rate. Copyright © 2015 Elsevier Ltd. All rights reserved.

Presentation and response timing accuracy in Adobe Flash and HTML5/JavaScript Web experiments.

PubMed

Reimers, Stian; Stewart, Neil

2015-06-01

Web-based research is becoming ubiquitous in the behavioral sciences, facilitated by convenient, readily available participant pools and relatively straightforward ways of running experiments: most recently, through the development of the HTML5 standard. Although in most studies participants give untimed responses, there is a growing interest in being able to record response times online. Existing data on the accuracy and cross-machine variability of online timing measures are limited, and generally they have compared behavioral data gathered on the Web with similar data gathered in the lab. For this article, we took a more direct approach, examining two ways of running experiments online-Adobe Flash and HTML5 with CSS3 and JavaScript-across 19 different computer systems. We used specialist hardware to measure stimulus display durations and to generate precise response times to visual stimuli in order to assess measurement accuracy, examining effects of duration, browser, and system-to-system variability (such as across different Windows versions), as well as effects of processing power and graphics capability. We found that (a) Flash and JavaScript's presentation and response time measurement accuracy are similar; (b) within-system variability is generally small, even in low-powered machines under high load; (c) the variability of measured response times across systems is somewhat larger; and (d) browser type and system hardware appear to have relatively small effects on measured response times. Modeling of the effects of this technical variability suggests that for most within- and between-subjects experiments, Flash and JavaScript can both be used to accurately detect differences in response times across conditions. Concerns are, however, noted about using some correlational or longitudinal designs online.

Applying a coupled hydrometeorological simulation system to flash flood forecasting over the Korean Peninsula

NASA Astrophysics Data System (ADS)

Ryu, Young; Lim, Yoon-Jin; Ji, Hee-Sook; Park, Hyun-Hee; Chang, Eun-Chul; Kim, Baek-Jo

2017-11-01

In flash flood forecasting, it is necessary to consider not only traditional meteorological variables such as precipitation, evapotranspiration, and soil moisture, but also hydrological components such as streamflow. To address this challenge, the application of high resolution coupled atmospheric-hydrological models is emerging as a promising alternative. This study demonstrates the feasibility of linking a coupled atmospheric-hydrological model (WRF/WRFHydro) with 150-m horizontal grid spacing for flash flood forecasting in Korea. The study area is the Namgang Dam basin in Southern Korea, a mountainous area located downstream of Jiri Mountain (1915 m in height). Under flash flood conditions, the simulated precipitation over the entire basin is comparable to the domain-averaged precipitation, but discharge data from WRF-Hydro shows some differences in the total available water and the temporal distribution of streamflow (given by the timing of the streamflow peak following precipitation), compared to observations. On the basis of sensitivity tests, the parameters controlling the infiltration of excess precipitation and channel roughness depending on stream order are refined and their influence on temporal distribution of streamflow is addressed with intent to apply WRF-Hydro to flash flood forecasting in the Namgang Dam basin. The simulation results from the WRF-Hydro model with optimized parameters demonstrate the potential utility of a coupled atmospheric-hydrological model for forecasting heavy rain-induced flash flooding over the Korean Peninsula.

[The P300-based brain-computer interface: presentation of the complex "flash + movement" stimuli].

PubMed

Ganin, I P; Kaplan, A Ia

2014-01-01

The P300 based brain-computer interface requires the detection of P300 wave of brain event-related potentials. Most of its users learn the BCI control in several minutes and after the short classifier training they can type a text on the computer screen or assemble an image of separate fragments in simple BCI-based video games. Nevertheless, insufficient attractiveness for users and conservative stimuli organization in this BCI may restrict its integration into real information processes control. At the same time initial movement of object (motion-onset stimuli) may be an independent factor that induces P300 wave. In current work we checked the hypothesis that complex "flash + movement" stimuli together with drastic and compact stimuli organization on the computer screen may be much more attractive for user while operating in P300 BCI. In 20 subjects research we showed the effectiveness of our interface. Both accuracy and P300 amplitude were higher for flashing stimuli and complex "flash + movement" stimuli compared to motion-onset stimuli. N200 amplitude was maximal for flashing stimuli, while for "flash + movement" stimuli and motion-onset stimuli it was only a half of it. Similar BCI with complex stimuli may be embedded into compact control systems requiring high level of user attention under impact of negative external effects obstructing the BCI control.

In Situ Detection of Macronutrients and Chloride in Seawater by Submersible Electrochemical Sensors.

PubMed

Cuartero, Maria; Crespo, Gaston; Cherubini, Thomas; Pankratova, Nadezda; Confalonieri, Fabio; Massa, Francesco; Tercier-Waeber, Mary-Lou; Abdou, Melina; Schäfer, Jörg; Bakker, Eric

2018-04-03

A new submersible probe for the in situ detection of nitrate, nitrite, and chloride in seawater is presented. Inline coupling of a desalination unit, an acidification unit, and a sensing flow cell containing all-solid-state membrane electrodes allows for the potentiometric detection of nitrate and nitrite after removal of the key interfering ions in seawater, chloride and hydroxide. Thus, the electrodes exhibited attractive analytical performances for the potentiometric detection of nitrate and nitrite in desalinated and acidified seawater: fast response time ( t 95 < 12 s), excellent stability (long-term drifts of <0.5 mV h -1 ), good reproducibility (calibration parameter deviation of <3%), and satisfactory accuracy (uncertainties <8%Diff compared to reference technique). The desalination cell, which can be repetitively used for about 30 times, may additionally be used as an exhaustive, and therefore calibration-free, electrochemical sensor for chloride and indirect salinity detection. The detection of these two parameters together with nitrate and nitrite may be useful for the correlation of relative changes in macronutrient levels with salinity cycles, which is of special interest in recessed coastal water bodies. The system is capable of autonomous operation during deployment, with routines for repetitive measurements (every 2 h), data storage and management, and computer visualization of the data in real time. In situ temporal profiles observed in the Arcachon Bay (France) showed valuable environmental information concerning tide-dependent cycles of nitrate and chloride levels in the lagoon, which are here observed for the first time using direct in situ measurements. The submersible probe based on membrane electrodes presented herein may facilitate the study of biogeochemical processes occurring in marine ecosystems by the direct monitoring of nitrate and nitrite levels, which are key chemical targets in coastal waters.

Daily Physical Activity and Hot Flashes in the Study of Women's Health Across the Nation FLASHES Study

PubMed Central

Gibson, Carolyn; Matthews, Karen; Thurston, Rebecca

2014-01-01

Objective To examine the role of physical activity in menopausal hot flashes. Competing models conceptualize physical activity as a risk or protective factor for hot flashes. Few studies have examined this relationship prospectively using physiologic measures of hot flashes and physical activity. Design Over two 48 hour-periods, 51 participants wore a physiologic hot flash monitor and activity monitor, and reported their hot flashes in an electronic diary. Physiologic hot flashes, reported hot flashes and reported hot flashes without physiological corroboration were related to activity changes using hierarchical generalized linear modeling, adjusting for potential confounders. Setting Community. Patients Midlife women. Interventions None. Main Outcome Measures Physiologically-detected hot flashes and reported hot flashes with and without physiologic corroboration. Results Hot flash reports without physiologic corroboration were more likely after activity increases (OR 1.04, 95% CI: 1.00-1.10, p=.01), particularly among women with higher levels of depressive symptoms (interaction p=.02). No other types of hot flashes were related to physical activity. Conclusion Acute increases in physical activity were associated with increased reporting of hot flashes lacking physiologic corroboration, particularly among women with depressive symptoms. Clinicians should consider the role of symptom perception and reporting in relations between physical activity and hot flashes. PMID:24491454

Counteracting ammonia inhibition during anaerobic digestion by recovery using submersible microbial desalination cell.

PubMed

Zhang, Yifeng; Angelidaki, Irini

2015-07-01

Ammonia inhibition is one of the most frequent and serious problems in biogas plants. In this study, a novel hybrid system consisting of a submersible microbial desalination cell (SMDC) and a continuous stirred tank reactor (CSTR) was developed for counteracting ammonia inhibition during anaerobic digestion (AD) with simultaneous in situ ammonia recovery and electricity production. The SMDC was powered by acetate in a buffer solution, while synthetic ammonia-rich wastewater was used as the feeding of the CSTR. Under continuous operation, ammonia recovery rate of 86 g-N/m(2) /day and current density of 4.33 A/m(2) were achieved at steady-state condition. As a result, 112% extra biogas was produced due to ammonia recovery by the SMDC. High-throughput sequencing showed that ammonia recovery had an impact on the microbial community structures in the SMDC and CSTR. Considering the additional economic benefits of biogas enhancement and possible wastewater treatment, the SMDC may represent a cost-effective and environmentally friendly method for waste resources recovery and biomethanation of ammonia-rich residues. © 2015 Wiley Periodicals, Inc.

Improved performance of the microbial electrolysis desalination and chemical-production cell with enlarged anode and high applied voltages.

PubMed

Ye, Bo; Luo, Haiping; Lu, Yaobin; Liu, Guangli; Zhang, Renduo; Li, Xiao

2017-11-01

The aim of this study was to improve performance of the microbial electrolysis desalination and chemical-production cell (MEDCC) using enlarged anode and high applied voltages. MEDCCs with anode lengths of 9 and 48cm (i.e., the 9cm-anode MEDCC and 48cm-anode MEDCC, respectively) were tested under different voltages (1.2-3.0V). Our results demonstrated for the first time that the MEDCC could maintain high performance even under the applied voltage higher than that for water dissociation (i.e., 1.8V). Under the applied voltage of 2.5V, the maximum current density in the 48cm-anode MEDCC reached 32.8±2.6A/m 2 , which is one of the highest current densities reported so far in the bioelectrochemical system (BES). The relative abundance of Geobacter was changed along the anode length. Our results show the great potential of the BES with enlarged anode and high applied voltages. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tetramethyl ammonium hydroxide production using the microbial electrolysis desalination and chemical-production cell with long anode.

PubMed

Ye, Bo; Lu, Yaobin; Luo, Haiping; Liu, Guangli; Zhang, Renduo

2018-03-01

The aim of this study was to investigate the feasibility to improve the tetramethyl ammonium hydroxide (TMAH) production in the microbial electrolysis desalination and chemical-production cell (MEDCC) with long anode of 48 cm. Different concentrations of tetramethylammonium chloride (0.3-0.7 M) and applied voltages (1.5-3.5 V) were tested in the MEDCC. With 0.6 M of tetramethylammonium chloride as the raw material and under the applied voltage of 3.5 V, the maximum TMAH production rate in the MEDCC reached 1.13 ± 0.12 mmol/h, which was 9.4 times higher than those previously reported in the MEDCCs. The maximum current density of 41.0 ± 4.0 A/m 2 in the MEDCC was obtained, which was the highest value in the bioelectrochemical systems using the carbon cloth or carbon brush as the anode so far. Our results should provide a promising method to improve the TMAH production and boost the MEDCC application. Copyright © 2018 Elsevier Ltd. All rights reserved.

Electronic desalting for controlling the ionic environment in droplet-based biosensing platforms

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

Swaminathan, Vikhram Vilasur; Dak, Piyush; Alam, Muhammad A., E-mail: rbashir@illinois.edu, E-mail: alam@purdue.edu

2015-02-02

The ability to control the ionic environment in saline waters and aqueous electrolytes is useful for desalination as well as electronic biosensing. We demonstrate a method of electronic desalting at micro-scale through on-chip micro electrodes. We show that, while desalting is limited in bulk solutions with unlimited availability of salts, significant desalting of ≥1 mM solutions can be achieved in sub-nanoliter volume droplets with diameters of ∼250 μm. Within these droplets, by using platinum-black microelectrodes and electrochemical surface treatments, we can enhance the electrode surface area to achieve >99% and 41% salt removal in 1 mM and 10 mM salt concentrations, respectively. Through self-consistentmore » simulations and experimental measurements, we demonstrate that conventional double-layer theory over-predicts the desalting capacity and, hence, cannot be used to model systems that are mass limited or undergoing significant salt removal from the bulk. Our results will provide a better understanding of capacitive desalination, as well as a method for salt manipulation in high-throughput droplet-based microfluidic sensing platforms.« less

Study the effect of active carbon modified using HNO3 for carbon electrodes in capacitive deionization system

NASA Astrophysics Data System (ADS)

Blegur, Ernes Josias; Endarko

2017-01-01

Carbon electrodes prepared with crosslink method for desalination purpose has been synthesized and characterized. The carbon electrodes were synthesized with activated carbon (700 - 1400 m2/g) and polyvinyl alcohol (PVA) as a binder using crosslink method with temperature crosslink at 120°C. Electrochemical properties of carbon electrodes were examined using electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The proposed study was to measure the salt-removal percentage of 330 µS/cm NaCl using a capacitive deionization (CDI) unit cell prepared with two pairs of carbon electrodes. The applied potential of 2.0 V and a flow rate of 25 mL/min were used to desalination tests. The result showed that the greatest value of the percentage of salt-removal was achieved at 36.1% for the carbon electrodes with Active Carbon Modified (ACM) while the salt-removal percentage for the Active Carbon (AC) electrodes only at 22%. The fact indicates that the active carbon modified using HNO3 can improve the efficiency of CDI about 14%.

The potential of high heat generating granites as EGS source to generate power and reduce CO2 emissions, western Arabian shield, Saudi Arabia

NASA Astrophysics Data System (ADS)

Chandrasekharam, D.; Lashin, A.; Al Arifi, N.; Al Bassam, A.; El Alfy, M.; Ranjith, P. G.; Varun, C.; Singh, H. K.

2015-12-01

Saudi Arabia's dependence on oil and gas to generate electricity and to desalinate sea water is widely perceived to be economically and politically unsustainable. A recent business as usual simulation concluded that the Kingdom would become an oil importer by 2038. There is an opportunity for the country to over come this problem by using its geothermal energy resources. The heat flow and heat generation values of the granites spread over a cumulative area of 161,467 sq. km and the regional stress regime over the western Saudi Arabian shield strongly suggest that this entire area is potential source of energy to support 1) electricity generation, 2) fresh water generation through desalination and 3) extensive agricultural activity for the next two decades. The country can adopt a policy to harness this vast untapped enhanced geothermal systems (EGS) to mitigate climate and fresh water related issues and increase the quantity of oil for export. The country has inherent expertise to develop this resource.

The valuation of water quality: effects of mixing different drinking water qualities.

PubMed

Rygaard, Martin; Arvin, Erik; Binning, Philip J

2009-03-01

As water supplies increasingly turn to use desalination technologies it becomes relevant to consider the options for remineralization and blending with mineral rich water resources. We present a method for analyzing economic consequences due to changes in drinking water mineral content. Included impacts are cardiovascular diseases, dental caries, atopic eczema, lifetime of dish and clothes washing machines, heat exchangers, distribution systems, bottled water consumption and soap usage. The method includes an uncertainty assessment that ranks the impacts having the highest influence on the result and associated uncertainty. Effects are calculated for a scenario where 50% of Copenhagen's water supply is substituted by desalinated water. Without remineralization the total impact is expected to be negative (euro -0.44+/-0.2/m(3)) and individual impacts expected in the range of euro 0.01-0.51/m(3) delivered water. Health impacts have the highest contribution to impact size and uncertainty. With remineralization it is possible to reduce several negative impacts and the total impact is expected to be positive (euro 0.14+/-0.08/m(3)).

Electronic desalting for controlling the ionic environment in droplet-based biosensing platforms

NASA Astrophysics Data System (ADS)

Swaminathan, Vikhram Vilasur; Dak, Piyush; Reddy, Bobby; Salm, Eric; Duarte-Guevara, Carlos; Zhong, Yu; Fischer, Andrew; Liu, Yi-Shao; Alam, Muhammad A.; Bashir, Rashid

2015-02-01

The ability to control the ionic environment in saline waters and aqueous electrolytes is useful for desalination as well as electronic biosensing. We demonstrate a method of electronic desalting at micro-scale through on-chip micro electrodes. We show that, while desalting is limited in bulk solutions with unlimited availability of salts, significant desalting of ≥1 mM solutions can be achieved in sub-nanoliter volume droplets with diameters of ˜250 μm. Within these droplets, by using platinum-black microelectrodes and electrochemical surface treatments, we can enhance the electrode surface area to achieve >99% and 41% salt removal in 1 mM and 10 mM salt concentrations, respectively. Through self-consistent simulations and experimental measurements, we demonstrate that conventional double-layer theory over-predicts the desalting capacity and, hence, cannot be used to model systems that are mass limited or undergoing significant salt removal from the bulk. Our results will provide a better understanding of capacitive desalination, as well as a method for salt manipulation in high-throughput droplet-based microfluidic sensing platforms.

Thermonuclear flashes on hydrogen/helium accreting carbon monoxide white dwarfs and structure of exotic nuclei

NASA Astrophysics Data System (ADS)

Mitchell, Joseph P.

We studied H-shell flashes on CO WDs accreting Hydrogen rich matter in regimes where they are believed to be on the border of stable accretion and of having dynamical mass loss. These systems are believed to be progenitors of SNe Ia, however, there is still some question of what range of accretion rates and WD masses allow for growth to the Chandrasekhar mass, if any do at all. Flashes that result in mass loss are also of interest as they enrich the Inter Stellar Medium. Use of an explicit hydro code has allowed for the observation of a new physical effect from wave dissipation. With our high time resolution, energy transport via waves, and detailed EOS, we found that at the onset of the flash, a reduction in the degeneracy pressure due to electron captures, results in a reduction of the total pressure. With a gravitational acceleration on the order of 108 in the shell, a reduction of the total pressure by 1% results in an in fall acceleration of 10 kms2 . With such a strong in fall, compressional heating results in a hotter flash, with results showing temperatures over a billion degrees in all models. These high temperatures had consequences on the nucleosynthesis, as they allowed for rp-breakout during the flash. The effect of a "double" flash was found in one model. This resulted when the flash stalled in the H-shell, resulting in high temperature burning in only a portion of the shell. Once the H was exhausted in the flash region, cooling occurred and there was contraction of the H exhausted region. This contraction caused an in fall of the un-exhausted region which via compressional heating resulted in the flash to occur in the un-exhausted region. Such an effect may happen in any progenitor system in which the flash stalls and compression afterwards is suitable for a re-start of the flash. This effect may be observable with the current generation of instruments. With the high temperatures found in the flashes, rp-breakout nucleosynthesis was found to occur. Occurrence of rp-nucleosynthesis in these objects may make important sources of the chemical enrichment of isotopes below the iron group that are not know to be synthesized in hydrostatic stellar burning. The existence of rp-breakout in the flashes, shows the importance of nuclear physics in these objects. More precise nuclear reaction rate data are needed for proper energy generation and chemical evolution. With the occurrence of rp-nucleosynthesis in our models, it is especially advantageous to study radioactive proton rich nuclei. These studies are not without many difficulties in the laboratory, as many of the studies require the use of low intensity radioactive beams making clean, high statistic studies difficult. To address this issue, the hybrid target technique was used. This target technique was found to be a great tool for studying resonant proton scattering with exotic beams. It has been used to measure elastic and inelastic excitation functions in the study of 8B via 7Be+p scattering, as well as 12N+p elastic scattering. With such success, the hybrid target technique can be a very useful tool for studying reactions that are important in the rp-process. We have studied the structure of the astrophysically important, radioactive isotope 8B. Three new resonances have been suggested, a 0+1,2+2 , and 1+2 which were predominantly in the inelastic channel and never before seen in previous studies. However, due to their high excitation energies and narrow width, none of the resonances are expected to effect the astrophysically important 7Be(p, gamma) reaction rate. Results were compared to continuum shell model as well as ab initio calculations and found to be in good agreement with both sets of predictions, with the notable exception of the 2+2 state. (Abstract shortened by UMI.)

Lightning hazard region over the maritime continent observed from satellite and climate change threat

NASA Astrophysics Data System (ADS)

Ilhamsyah, Y.; Koesmaryono, Y.; Hidayat, R.; Murjaya, J.; Nurjaya, I. W.; Rizwan

2017-02-01

Climate change would lead to such hydrometeorological disaster as: flash-flood, landslide, hailstone, lightning, and twister become more likely to happen in the future. In terms of lightning event, one research question arise of where lightning would be mostly to strike over the Maritime Continent (MC)?. The objective of the research is to investigate region with high-density of lightning activity over MC by mapping climatological features of lightning flashes derived from onboard NASA-TRMM Satellite, i.e. Optical Transient Detector/Lightning Imaging Sensor (OTD/LIS). Based on data retrieved since 1995-2013, it is seasonally observed that during transition season March to May, region with high vulnerability of lightning flashes cover the entire Sumatra Island, the Malacca Strait, and Peninsular Malaysia as well as Java Island. High-frequent of lightning activity over the Malacca Strait is unique since it is the only sea-region in the world where lightning flashes are denser. As previously mentioned that strong lightning activity over the strait is driven by mesoscale convective system of Sumatra Squalls due to convergences of land breeze between Sumatra and Peninsular Malaysia. Lightning activity over the strait is continuously observed throughout season despite the intensity reduced. Java Island, most populated island, receive high-density of lightning flashes during rainy season (December to February) but small part in the northwestern of Java Island, e.g., Bogor and surrounding areas, the density of lightning flashes are high throughout season. Northern and southern parts of Kalimantan and Central part of Sulawesi are also prone to lightning activity particularly during transition season March to May and September to November. In the eastern part of MC, Papua receive denser lightning flashes during September to November. It is found that lightning activity are mostly concentrated over land instead of ocean which is in accordance with diurnal convective precipitation event due to the existence of numerous mountainous island in MC. The malacca strait however is the only exception and turn into a unique characteristic of convective system over MC and the only sea-region in the world where lightning activity is the greatest.

Analytical modeling of flash-back phenomena. [premixed/prevaporized combustion system

NASA Technical Reports Server (NTRS)

Feng, C. C.

1979-01-01

To understand the flame flash-back phenomena more extensively, an analytical model was formed and a numerical program was written and tested to solve the set of differential equations describing the model. Results show that under a given set of conditions flame propagates in the boundary layer on a flat plate when the free stream is at or below 1.8 m/s.

Towards a better knowledge of flash flood forecasting at the Three Gorges Region: Progress over the past decade and challenges ahead

NASA Astrophysics Data System (ADS)

Li, Zhe; Yang, Dawen; Yang, Hanbo; Wu, Tianjiao; Xu, Jijun; Gao, Bing; Xu, Tao

2015-04-01

The study area, the Three Gorges Region (TGR), plays a critical role in predicting the floods drained into the Three Gorges Reservoir, as reported local floods often exceed 10000m3/s during rainstorm events and trigger fast as well as significant impacts on the Three Gorges Reservoir's regulation. Meanwhile, it is one of typical mountainous areas in China, which is located in the transition zone between two monsoon systems: the East Asian monsoon and the South Asian (Indian) monsoon. This climatic feature, combined with local irregular terrains, has shaped complicated rainfall-runoff regimes in this focal region. However, due to the lack of high-resolution hydrometeorological data and physically-based hydrologic modeling framework, there was little knowledge about rainfall variability and flood pattern in this historically ungauged region, which posed great uncertainties to flash flood forecasting in the past. The present study summarize latest progresses of regional flash floods monitoring and prediction, including installation of a ground-based Hydrometeorological Observation Network (TGR-HMON), application of a regional geomorphology-based hydrological model (TGR-GBHM), development of an integrated forecasting and modeling system (TGR-INFORMS), and evaluation of quantitative precipitation estimations (QPE) and quantitative precipitation forecasting (QPF) products in TGR flash flood forecasting. With these continuing efforts to improve the forecasting performance of flash floods in TGR, we have addressed several critical issues: (1) Current observation network is still insufficient to capture localized rainstorms, and weather radar provides valuable information to forecast flash floods induced by localized rainstorms, although current radar QPE products can be improved substantially in future; (2) Long-term evaluation shows that the geomorphology-based distributed hydrologic model (GBHM) is able to simulate flash flooding processes reasonably, while model performance will decline at hourly scale with larger uncertainties. However, model comparison suggests that this physically-based distributed model (GBHM), compared with a traditional lumped model (Xin'anjiang model), shows more robust performance and larger transferability for prediction in those ungauged basins in TGR; (3) Operational test of our integrated forecasting system (TRG-INFORMS) shows that it works reasonably to simulate the flood routing in Three Gorges reservoir, indicating the accuracy of simulation of total floods generated at region scale; (4) Current operational QPF is too coarse to provide valuable information even for flood forecasting of whole TGR, thus, downscaling and high-resolution QPF are necessary to unravel the potentials of weather forecasting. Finally, according to these results, we also discuss about some possible solutions with high priority for future advanced forecasting scheme of local flash floods in TGR.

Geochemical processes in a calcareous sandstone aquifer during managed aquifer recharge with desalinated seawater

NASA Astrophysics Data System (ADS)

Ganot, Yonatan; Russak, Amos; Siebner, Hagar; Bernstein, Anat; Katz, Yoram; Guttman, Jospeh; Kurtzman, Daniel

2017-04-01

In the last three years we monitor Managed Aquifer Recharge (MAR) of post-treated desalinated seawater (PTDES) in an infiltration pond, at the Menashe site that overlies the northern part of the Israeli Coastal Aquifer. The PTDES are stabilized with CaCO3 during post-treatment in the desalination plant and their chemical composition differs from those of any other water recharged to the aquifer and of the natural groundwater. We use suction cups in the unsaturated zone, shallow observation wells within the pond and production wells that encircles the MAR Menashe site, to study the geochemical processes during MAR with PTDES. Ion-enrichment (remineralization) of the recharged water was observed in both unsaturated zone and shallow observation wells samples. Enrichment occurs mainly in the first few meters below the pond surface by ion-exchange processes. Mg2+ enrichment is most prominent due to its deficiency in the PTDES. It is explained by ion-exchange with Ca2+, as the PTDES (enriched with Ca2+) infiltrates through a calcareous-sandstone aquifer with various amount of adsorbed Mg2+ (3-27 meq/kg). Hence, the higher concentration of Ca+2 in the PTDES together with its higher affinity to the sediments promotes the release of Mg2+ ions to the recharged water. Water isotopes analysis of the production wells were used to estimate residence time and mixing with local groundwater. At the end of 2016, it was found that the percentage of PTDES in adjacent down-gradient production wells was around 10%, while more distant or up-gradient wells show no mixing with PTDES. The distinct isotope contrast between the recharged desalinated seawater (δ2H=+11.2±0.2‰) and the local groundwater (δ2H ranged from -22.7 to -16.7‰) is a promising tool to evaluate future mixing processes at the Menshae MAR site. Using the Menashe MAR system for remineralization could be beneficial as a primary or complementary post-treatment technique. However, the sustainability of this process is still questionable, as the recharged water remineralization is accompanied by mineral depletion of the pond sediments. Study on the feasibility of this remineralization scheme is currently ongoing using laboratory column experiments and reactive transport modelling.

Triggered lightning strikes to aircraft and natural intracloud discharges

NASA Technical Reports Server (NTRS)

Mazur, Vladislav

1989-01-01

The physical model of Mazur (1989) for triggering lightning strikes by aircraft was used to interpret the initiation of intracloud flashes observed by the French UHF-VHF interferometric system. It is shown that both the intracloud discharges and airplane-triggered lightning strikes were initiated by simultaneous bidirectional development of the negative stepped leader and the positive leader-continous current process. However, the negative stepped leader phase in triggered flashes is of shorter duration (tens of milliseconds), than that in intracloud flashes (usually hundreds of milliseconds). This is considered to be due to the fact that, on the aircraft there is a single initiation process, versus the numerous initiation processes that occur inside the cloud.

Adverse Effects of Induced Hot Flashes on Objectively Recorded and Subjectively Reported Sleep: Results of a Gonadotropin-Releasing Hormone Agonist Experimental Protocol

PubMed Central

Joffe, Hadine; White, David P.; Crawford, Sybil L.; McCurnin, Kristin E.; Economou, Nicole; Connors, Stephanie; Hall, Janet E.

2013-01-01

Objectives The impact of hot flashes on sleep is of great clinical interest, but results are inconsistent, especially when both hot flashes and sleep are measured objectively. Using objective and subjective measurements, we examined the impact of hot flashes on sleep by inducing hot flashes with a gonadotropin-releasing hormone agonist (GnRHa). Methods The GnRHa leuprolide was administered to 20 healthy premenopausal volunteers without hot flashes or sleep disturbances. Induced hot flashes were assessed objectively (skin-conductance monitor) and subjectively (daily diary) during one-month follow-up. Changes from baseline in objective (actigraphy) and subjective sleep quality (Pittsburgh Sleep Quality Index [PSQI]) were compared between women who did and did not develop objective hot flashes, and, in parallel analyses, subjective hot flashes. Results New-onset hot flashes were recorded in 14 (70%) and reported by 14 (70%) women (80% concordance). Estradiol was universally suppressed. Objective sleep efficiency worsened in women with objective hot flashes and improved in women without objective hot flashes (median decrease 2.6%, increase 4.2%, p=0.005). Subjective sleep quality worsened more in those with than without subjective hot flashes (median increase PSQI 2.5 vs. 1.0, p=0.03). Objective hot flashes were not associated with subjective sleep quality, nor were subjective symptoms linked to objective sleep measures. Conclusions This experimental model of induced hot flashes demonstrates a causal relationship between hot flashes and poor sleep quality. Objective hot flashes result in worse objective sleep efficiency, while subjective hot flashes worsen perceived sleep quality. PMID:23481119

Chapter Two – Separations Versus Sustainability: There is No ...

EPA Pesticide Factsheets

Separation operations in chemical processes are generally “uphill” tasks—defying natural tendencies. Historically, such separations have been accomplished by applying generous portions of fossil energy and materials, leaving behind a large environmental footprint. In this chapter, progress in reducing this footprint will be discussed with examples in biofuel production, desalination, and carbon dioxide capture. Industrial separation processes have a significant energy and environmental footprint. Sizeable reductions in energy usage could be achieved by replacing energy-intensive processes like distillation with low-energy separation systems such as membranes, extraction, sorption, or synergistic hybrid systems of low- and high-energy systems.

Effect of optical digitizer selection on the application accuracy of a surgical localization system-a quantitative comparison between the OPTOTRAK and flashpoint tracking systems

NASA Technical Reports Server (NTRS)

Li, Q.; Zamorano, L.; Jiang, Z.; Gong, J. X.; Pandya, A.; Perez, R.; Diaz, F.

1999-01-01

Application accuracy is a crucial factor for stereotactic surgical localization systems, in which space digitization camera systems are one of the most critical components. In this study we compared the effect of the OPTOTRAK 3020 space digitization system and the FlashPoint Model 3000 and 5000 3D digitizer systems on the application accuracy for interactive localization of intracranial lesions. A phantom was mounted with several implantable frameless markers which were randomly distributed on its surface. The target point was digitized and the coordinates were recorded and compared with reference points. The differences from the reference points represented the deviation from the "true point." The root mean square (RMS) was calculated to show the differences, and a paired t-test was used to analyze the results. The results with the phantom showed that, for 1-mm sections of CT scans, the RMS was 0.76 +/- 0. 54 mm for the OPTOTRAK system, 1.23 +/- 0.53 mm for the FlashPoint Model 3000 3D digitizer system, and 1.00 +/- 0.42 mm for the FlashPoint Model 5000 system. These preliminary results showed that there is no significant difference between the three tracking systems, and, from the quality point of view, they can all be used for image-guided surgery procedures. Copyright 1999 Wiley-Liss, Inc.

Effect of optical digitizer selection on the application accuracy of a surgical localization system-a quantitative comparison between the OPTOTRAK and flashpoint tracking systems.

PubMed

Li, Q; Zamorano, L; Jiang, Z; Gong, J X; Pandya, A; Perez, R; Diaz, F

1999-01-01

Application accuracy is a crucial factor for stereotactic surgical localization systems, in which space digitization camera systems are one of the most critical components. In this study we compared the effect of the OPTOTRAK 3020 space digitization system and the FlashPoint Model 3000 and 5000 3D digitizer systems on the application accuracy for interactive localization of intracranial lesions. A phantom was mounted with several implantable frameless markers which were randomly distributed on its surface. The target point was digitized and the coordinates were recorded and compared with reference points. The differences from the reference points represented the deviation from the "true point." The root mean square (RMS) was calculated to show the differences, and a paired t-test was used to analyze the results. The results with the phantom showed that, for 1-mm sections of CT scans, the RMS was 0.76 +/- 0. 54 mm for the OPTOTRAK system, 1.23 +/- 0.53 mm for the FlashPoint Model 3000 3D digitizer system, and 1.00 +/- 0.42 mm for the FlashPoint Model 5000 system. These preliminary results showed that there is no significant difference between the three tracking systems, and, from the quality point of view, they can all be used for image-guided surgery procedures. Copyright 1999 Wiley-Liss, Inc.