WorldWideScience

Sample records for bleach filtrate reuse

  1. Control of the Accumulation of Non-Process Elements in Pulp Mills with Bleach Filtrate Reuse: A Chemical Equilibrium Approach to Predicting the Partitioning of Metals in Pulp Mill and Bleach Plant Streams

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, W.J. Jr.; Rudie, A.W.; Schmidl, G.W.; Sinquefield, S.A.; Rorrer, G.L.; Laver, M.L.; Yantasee, W.; Ming, D.

    2000-08-01

    The overall goal of this project was to develop fundamental, experimentally based methods for predicting the solubility or organic and inorganic matter and their interactions in recycled effluent from kraft pulp mills and bleach plants. This included: characterizing the capacity of wood pulp and dissolved organic matter to bind metal ions, developing a thermodynamic database of properties needed to describe the solubility of inorganic matter in pulp mill streams, incorporation of the database into equilibrium calculation software for predicting the solubility of the metals of interest, and evaluating its capability to predict the distribution of the metals between pulp fibers, inorganic precipitates, and solution.

  2. Reuse of discarded deactivated bleaching earth in the bleaching of oils

    Directory of Open Access Journals (Sweden)

    Girgis, Adel Y.

    2005-03-01

    Full Text Available Discarded bleaching earth was used after its reactivation for the bleaching of sunflower, soybean and corn oils. The efficiency of reactivated bleaching earth was compared to the efficiency of virgin activated bleaching earth. Acid reactivated earth (pH 2.5-3 had a slightly higher content in silicone than virgin activated or neutralized reactivated earths. The best results in the color of sunflower and corn oils were obtained when neutralized earth (pH 6–7 was used at 1 and 2 % levels. Acid reactivated earth used at 2 % achieved a higher reduction in soybean oil color than virgin earth (pH 3 at the same dosage. Both reactivated earths reduced peroxide value, iron, conjugated dienes and soap, while they increased acidity and conjugated trienes. Furthermore, these reactivated earths determined higher decrements in the oil induction period than virgin earth. Reactivated earth could be used for 5 cycles for the bleaching of soybean or corn oils and for more than 6 cycles for sunflower oil.Tierra decolorante desechada, fue empleada, tras su reactivación para decolorar aceites de girasol, soja y maíz. La eficiencia de la tierra decolorante reactivada fue comparada con la de la virgen activada. La tierra reactivada ácida (pH 2,5–3 tuvo ligeramente mayor contenido en silicona que la tierra virgen o la reactivada neutra. Los mejores resultados en el color de los aceites de girasol y maíz fueron obtenidos cuando se emplearon niveles del 1 y 2 % de tierra reactivada neutra (pH 6-7. La tierra ácida reactivada, usada al 2 % consiguió una mayor reducción del color del aceite de soja, que una misma dosis de tierra virgen (pH 3. Ambas tierras reactivadas redujeron el índice de peróxidos, hierro, dienos conjugados y jabón de los aceites, mientras que hicieron aumentar la acidez y los trienos conjugados. Además, estas tierras reactivadas determinaron mayores descensos en los periodos de inducción del aceite que la tierra virgen. Las tierras

  3. Evaluation of white water reuse in the bleaching process for reducing fresh water consumption.

    Science.gov (United States)

    Andrade, A A; Glória, P M; d'Angelo, J V H; Perissotto, D O; Lima, R A

    2007-01-01

    The main objective of this work is to study the technical viability of using the effluent generated in paper machines (white water) in the wash presses of the bleaching stage, reducing fresh water consumption. As a case study, the industrial process of Ripasa S.A. Celulose e Papel was evaluated. White water rate is about 700 m3/h and it is not possible to reuse all this volume in the bleaching stage without causing operational problems (fouling in tubes and clogging in the screens). A mass balance of the bleaching unit was developed in an electronic spreadsheet in order to evaluate the possibility of reducing fresh water consumption, using only a fraction of the available white water in the wash presses. To achieve this objective some physical-chemistry properties of the white water stream and of other streams of the process were determined. The maximum concentration of some non-process elements (Si, Ca, Mn and Fe), which could accumulate in the process, were determined in order to establish some parameters to allow process integration of the streams involved, considering operational constraints. The results obtained have shown that it is possible to reduce approximately by 13% the consumption of fresh water and this methodology has been satisfactory.

  4. Wastewater filtration and re-use: An alternative water source for London

    International Nuclear Information System (INIS)

    Paul, Jonathan D.; Blunt, Martin J.

    2012-01-01

    hydrodynamic dispersion of aqueous contaminants within the chalk. -- Highlights: ► We propose a novel small-scale wastewater re-use scheme for the London Basin which makes use of the underlying chalk as a natural filtration system. ► Two possible locations are defined on the basis of low environmental impact and high degree of contaminant removal; the effects of pumping fluid into the Chalk are modelled at each location. ► The ‘channelling’ effect of fractures in the chalk rock mass is relatively unimportant. ► Laboratory-scale pumping experiments demonstrate contaminants being effectively arrested over small distances. ► The proposed scheme will contribute towards addressing the deficit in local water supplies, and will complement similar successful wastewater recycling projects across the UK and globally.

  5. Domestic wash water reclamation for reuse as commode water supply using filtration: Reverse-osmosis separation technique

    Science.gov (United States)

    Hall, J. B., Jr.; Batten, C. E.; Wilkins, J. R.

    1974-01-01

    A combined filtration-reverse-osmosis water recovery system has been evaluated to determine its capability to reclaim domestic wash water for reuse as a commode water supply. The system produced water that met all chemical and physical requirements established by the U.S. Public Health Service for drinking water with the exception of carbon chloroform extractables, methylene blue active substances, and phenols. It is thought that this water is of sufficient quality to be reused as commode supply water. The feasibility of using a combined filtration and reverse-osmosis technique for reclaiming domestic wash water has been established. The use of such a technique for wash-water recovery will require a maintenance filter to remove solid materials including those less than 1 micron in size from the wash water. The reverse-osmosis module, if sufficiently protected from plugging, is an attractive low-energy technique for removing contaminants from domestic wash water.

  6. Efficiency Evaluation of Filtration with Fluidized Bed for Treatment of Secondary Effluents for Reuse

    OpenAIRE

    Mohammad Hosaini; Rohallah Moradi; Gholam Hossain Safari

    2013-01-01

    Background & Objectives: Recently, deficient in atmospheric drop and discharges of wastewater effluents leads to serious threat for water resource. For that reason, for prevention of water source pollution and also reuse of wastewater effluents, treatment of such effluents seems to be necessary. Methods: In this work, fluidized bed reactor with a filter was used for treatment of effluents from Shahrak Gharb wastewater treatment plant. Various parameters such as BOD5, COD, TS, TP, TN and t...

  7. Efficiency Evaluation of Filtration with Fluidized Bed for Treatment of Secondary Effluents for Reuse

    Directory of Open Access Journals (Sweden)

    Mohammad Hosaini

    2013-12-01

    Full Text Available Background & Objectives: Recently, deficient in atmospheric drop and discharges of wastewater effluents leads to serious threat for water resource. For that reason, for prevention of water source pollution and also reuse of wastewater effluents, treatment of such effluents seems to be necessary. Methods: In this work, fluidized bed reactor with a filter was used for treatment of effluents from Shahrak Gharb wastewater treatment plant. Various parameters such as BOD5, COD, TS, TP, TN and turbidity were analyzed. The aluminum sulfate was used as coagulant for enhance removal efficiency. Results: The results of present work demonstrate that present system had higher treatment potential for secondary effluents. The amount of BOD5, COD and TP in system effluents was reached to below 1.75, 3.23, 0.5 mg/L, respectively. No removal efficiency was observed for TN. In addition, the amount of turbidity in system effluent was reached to below 1.04 NTU. The system represents lower removal efficiency for TS. In addition, higher removal efficiency is in the range of 5 to 7.5 m/h and increasing of surface loading upon to 10 m/h will decreases the removal efficiency. Conclusion: On general, the system represents higher removal potential for treatment of secondary effluent for reuse application.

  8. Peroxy bleaches

    International Nuclear Information System (INIS)

    Carson, P.A.; Fairclough, C.S.; Mauduit, C.; Colsell, M.

    2006-01-01

    Fabric laundering is now a sophisticated chemical process involving a variety of operations including bleaching. The chemistry of peroxy bleaches is described including the use of novel organic compounds to provide effective bleaching at the lower temperatures of modern wash cycles. The instability of peroxy compounds is illustrated using cameo case histories to relate theory and practice. Techniques available for determining their thermochemistry are summarised. A model is provided for hazard and risk assessment of development projects in general (particularly those involving new molecules, processes or formulations) from ideas phase through exploratory laboratory investigations to pilot plant scale-up and eventual manufacture and commercial exploitation. This paper is a prelude to Part 2, which describes the determination of thermodynamic and kinetic properties of peroxy bleaches and discusses the implication of the results in terms of precautions for their safe storage and incorporation into detergent formulations during processing

  9. The role of bleaching in pulp mill effluent effects on fish

    Energy Technology Data Exchange (ETDEWEB)

    Coakley, J.; Hodson, P.; Cross, T. [Queen`s Univ., School of Environmental Studies, Queen`s Univ., Kingston, ON (Canada); Van Heiningen, A. [New Brunswick Univ., Limerick Pulp and Paper Centre, Fredericton, NB (Canada)

    1999-05-01

    Sources and potency of mixed function oxygenase (MFO)-inducing compounds within a 5-stage chlorine dioxide bleaching sequence at a pulp and paper mill was determined. Environmental concerns regarding chlorinated organic materials and their toxicity to aquatic organisms caused many mills to switch to elemental chlorine-free bleaching processes, with the most common being the chlorine dioxide bleaching process. However, even with this switch, effluent from kraft pulp mills still affect aquatic organisms. In this study, bleach plant filtrates were collected from two kraft mills in Ontario. The filtrates were used in fish bioassays to assess MFO-inducing potency. Results showed that potency varied depending on the wood used (softwood or hardwood) and the bleaching stage. Filtrates produced in a lab were weak MFO inducers compared to mill filtrates.14 refs., 6 figs.

  10. Wastewater reuse

    OpenAIRE

    Milan R. Radosavljević; Vanja M. Šušteršič

    2013-01-01

    Water scarcity and water pollution are some of the crucial issues that must be addressed within local and global perspectives. One of the ways to reduce the impact of water scarcity  and to minimizine water pollution is to expand water and wastewater reuse. The local conditions including regulations, institutions, financial mechanisms, availability of local technology and stakeholder participation have a great influence on the decisions for wastewater reuse. The increasing awareness of food s...

  11. Vital tooth bleaching with Nightguard vital bleaching.

    Science.gov (United States)

    Haywood, V B; Robinson, F G

    1997-01-01

    Between July 1994 and May 1996, several landmark articles were published concerning the safety and efficacy of vital tooth bleaching with 10% carbamide peroxide in a customfitted tray. The American Dental Association (ADA) published guidelines for ADA acceptance, and three products received approval. Long-term clinical trials on 38 patients indicated 92% successful bleaching after 6 weeks of treatment. Results were stable in 74% of the patients at 1.5 years, and in 62% of the patients at 3-year follow-up with no further treatment. Clinical pulpal studies and periodontal studies indicated no detrimental safety problems, although some laboratory cell studies suggested concerns. The noncarcinogenic potential of 10% carbamide peroxide was established in animal studies. Successful bleaching of tetracycline-stained teeth was achieved after 6 months of treatment, with no tooth problems detected clinically or by scanning electron micrograph. Extended treatment times are effective on other stains from dentinogenesis imperfecta or nicotine. On insertion in the mouth, 10% carbamide peroxide elevated the pH in the tray and saliva. After 4 hours of clinical wear, over 60% of the newer, thicker materials (Opalescence [Ultraclent Products, South Jordon, UT] and Platinum [Colgate Oral Pharmaceuticals, Canton, MA]) was present and active in the tray. Nightguard vital bleaching seems to be the most cost-efficient, user-friendly, patient-accepted method of bleaching teeth available to the profession and is safe and effective. Over-the-counter products can have harmful effects on tooth structure and may not lighten teeth.

  12. Performances of nano filtration (NF) and reverse osmosis (RO) in textile industry waste water treatment

    International Nuclear Information System (INIS)

    Ellouze, E.; Souissi, S.; Ben Amar, R.; Ben Salah, A.; Jrad, A.

    2009-01-01

    Textile industry process (dyeing, bleaching, printing and finishing) require a high-water consumption generating high amounts of water. Reactive dyeing of 1Kg of cotton requires about 150 Litres of water and 40g reactive dye resulting in a large volume of strongly coloured effluents. This fact in combination with the current water scarcity makes necessary textile waste water reuse. In this paper experimental results obtained from the treatment by different membranes Micro filtration (MF), Nano filtration (NF) and Reverse Osmosis (RO) of Sitex industry waste water pretreated by biological activated sludge are presented and compared. The results obtained from direct Nano filtration performed at different transmembrane pressures (8 - 1 m - 2 for a Volumetric Concentration Factor (VCF) of 4 and that the osmotic pressure π= 4Bars. A high quality of treated effluent in term of colour removal and desalination was obtained for a VCF of 2: salinity retention rate (RR) 57 pour cent and discoloration almost 100 pour cent at pressure of 12 bar. While, the permeate flux obtained using the combination MF/RO at a different pressures 25 - 1 m- 2 for a VCF of 6 indicating an important fouling. In this case, the osmotic pressure varied from 6 to 28 bars. The optimum salinity and colour retention rate (RR) were 86 pour cent and 100 pour cent respectively obtained at a VCF of 2.

  13. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  14. Wastewater reuse

    Directory of Open Access Journals (Sweden)

    Milan R. Radosavljević

    2013-12-01

    Full Text Available Water scarcity and water pollution are some of the crucial issues that must be addressed within local and global perspectives. One of the ways to reduce the impact of water scarcity  and to minimizine water pollution is to expand water and wastewater reuse. The local conditions including regulations, institutions, financial mechanisms, availability of local technology and stakeholder participation have a great influence on the decisions for wastewater reuse. The increasing awareness of food safety and the influence of the countries which import food are influencing policy makers and agriculturists to improve the standards of wastewater reuse in agriculture. The environmental awareness of consumers has been putting pressure on the producers (industries to opt for environmentally sound technologies including those which conserve water and reduce the level of pollution. It may be observed that we have to move forwards to implement strategies and plans for wastewater reuse. However, their success and sustainability will depend on political will, public awareness and active support from national and international agencies to create favorable    environment for the promotion of environmentally sustainable technologies. Wastewater treatment has a long history, especially in agriculture, but also in industry and households. Poor quality of wastewater can pose a significant risk to the health of farmers and users of agricultural products. The World Health Organization (WHO is working on a project for the reuse of wastewater in agriculture. To reduce effects of human activities to the minimum, it is necessary to provide such technical and technological solutions that would on the one hand ensure complying with  the existing regulations and legislation, and on the other hand provide economically viable systems as seen through investments and operating costs. The use of wastewater The practice of using wastewater varies from country to country. Its

  15. Recycling and reuse of industrial wastes in Taiwan.

    Science.gov (United States)

    Wei, M S; Huang, K H

    2001-01-01

    Eighteen million metric tons of industrial wastes are produced every year in Taiwan. In order to properly handle the industrial wastes, the Taiwan Environmental Protection Administration (Taiwan EPA) has set up strategic programs that include establishment of storage, treatment, and final disposal systems, establishment of a management center for industrial wastes, and promotion of recycling and reuse of industrial wastes. The Taiwan EPA has been actively promoting the recycling and reuse of industrial wastes over the years. In July 1995 the Taiwan EPA amended and promulgated the Criteria for the Industrial Waste Storage, Collection and Processing Facility, July, 1995 that added articles related to general industrial waste recycling and reuse. In June 1996 the Taiwan EPA promulgated the Non-listed General Industrial Waste Reuse Application Procedures, June, 1996, followed by the Regulations Governing the Permitting of Hazardous Industrial Waste Reuse, June 1996, setting up a full regulatory framework for governing industrial waste reuse. To broaden the recycling and reuse of general industrial wastes, the Taiwan EPA has listed 14 industrial waste items for recycling and reuse, including waste paper, waste iron, coal ash, tempered high furnace bricks (cinder), high furnace bricks (cinder), furnace transfer bricks (cinder), sweetening dregs, wood (whole/part), glass (whole/part), bleaching earth, ceramics (pottery, brick, tile and cast sand), individual metal scraps (copper, zinc, aluminum and tin), distillery grain (dregs) and plastics. As of June 1999, 99 applications for reuse of industrial wastes had been approved with 1.97 million metric tons of industrial wastes being reused.

  16. BLEACHING NEPTUNE BALLS

    Directory of Open Access Journals (Sweden)

    BONET Maria Angeles

    2014-05-01

    Full Text Available Posidonia Oceanic is a seaweed from Mediterranean Sea and it is more concentrated at the Balerian SEA. This implies the Valencian Community also. It forms vaste underwater meadows in the sea and are part of the Mediterranean ecosystem. It is a sea-grass specie with fruits and flowers. Leaves are ribbon-like and they grow in winter and at the end of summer some of them are separated and arrive to some sea line. Fuit is separated and can floate, it is known as “the olive of the sea” mainly in Italy, or as the Neptune Balls. As it can be used in different fields, it is is being studied in order ro have the precitice tests. Some authors have reported the manufacturing of fully bio-based comites with a gluten matrix by hot-press molding. And it has been considered as an effective insulator for building industry or even though to determine the presence of mercure in the Mediterranean sea some years ago. As many applications can be designed from that fibers, it has been considered to be bleached in order to used them in fashionable products. Consequently, its original brown color is not the most suitable one and it should be bleached as many other cellulosic fibers. The aim of this paper is to bleache neptune balls however, the inner fibers were not accessible at all and it implied not to bleach the inner fibers in the neptune ball. Further studiesd will consider bleaching the individualized fibers.

  17. Optimization of acid-activated bentonites on bleaching of cotton oil

    International Nuclear Information System (INIS)

    Lacin, O.; Sayan, E.; Kirali, E.G.

    2013-01-01

    Bentonites are commonly used adsorbent on bleaching cotton oil to produce edible oil products. Bleaching capacities of neutralized cotton oil were investigated with acid-activated Arguvan and Kursunlu bentonites. Two models for acid activation of the bentonites were developed by using a full factorial experimental design and central composite design. The parameters used to develop these models were contact time, solid to liquid ratio, acid concentration and moisture of bentonite. By using a constrained optimization program, the maximum bleaching capacities of neutralized cotton oil were determined as 99.99% and 48.5% for Arguvan and Kursunlu, respectively. Optimum results showed that Turkish bentonites (especially Arguvan bentonite) have high bleaching ability and they can be used efficiently to bleach neutralized cotton oil by considering the favorable volume weight, capacity of oil adsorbed and filtration rate. (author)

  18. Aerosol filtration

    International Nuclear Information System (INIS)

    First, M.W.; Gilbert, H.

    1982-01-01

    Significant developments in high-efficiency filtration for nuclear applications are reviewed for the period 1968 to 1980. Topics of special interest include (1) factory (bench) and in-place test methods, (2) new developments in paper and filter unit construction methods, (3) vented containment air cleaning systems for liquid-metal fast breeder reactors and light-water-moderated reactors, and (4) decontamination of off-gases from nuclear waste volume-reduction processes. Standards development has been vigorously pursued during this period, but advances in filtration theory have been few. One of the significant changes likely to occur in the immediate future is adoption of the European style of high-efficiency particulate air filters instead of those which have been in service for the past three decades to obtain the benefits of having almost twice as much filter paper in the same filter cartridge

  19. Aerosol filtration

    International Nuclear Information System (INIS)

    First, M.W.; Gilbert, H.

    1981-01-01

    Significant developments in high efficiency filtration for nuclear applications are reviewed for the period 1968 to 1980. Topics of special interest include factory (bench) and in-place test methods, new developments in paper and filter unit construction methods, vented containment air cleaning systems for LMFBR and light water moderated reactors, and decontamination of offgases from nuclear waste volume reduction processes. It is noted that standards development has been vigorously pursued during this period but that advances in filtration theory have been few. One of the significant changes likely to occur in the immediate future is adoption of the European style of HEPA filters for those that have been in service for the past three decades to obtain the benefits of having almost twice as much filter paper in the same filter cartridge. 71 references

  20. Limits of Software Reuse

    NARCIS (Netherlands)

    Holenderski, L.

    2006-01-01

    Software reuse is considered one of the main techniques to increasesoftware productivity. We present two simple mathematical argumentsthat show some theoretical limits of reuse. It turns out that the increase of productivity due to internal reuse is at most linear, farfrom the needed exponential

  1. GSPEL - Air Filtration Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Evaluation capabilities for air filtration devicesThe Air Filtration Lab provides testing of air filtration devices to demonstrate and validate new or legacy system...

  2. Coral reef bleaching: ecological perspectives

    Science.gov (United States)

    Glynn, P. W.

    1993-03-01

    Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt

  3. Recycling of cleach plant filtrates by electrodialysis removal of inorganic non-process elements.

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, S. P.; Pfromm, P.; Henry, M. P.; Fracaro, A. T.; Swanstrom, C. P.; Moon, P.; Energy Systems; Inst. of Paper Science and Tech.

    2000-11-01

    Water use in the pulp and paper industry is very significant, and the U.S. pulp and paper industries as well as other processing industries are actively pursuing water conservation and pollution prevention by in-process recycling of water. Bleach plant effluent is a large portion of the water discharged from a typical bleached kraft pulp mill. The recycling of bleach plant effluents to the kraft recovery cycle is widely regarded as an approach to low effluent bleached kraft pulp production. The focus of this work has been on developing an electrodialysis process for recycling the acidic bleach plant effluent of bleached Kraft pulp mills. Electrodialysis is uniquely suited as a selective kidney to remove non-process elements (NPEs) from bleach plant effluent before they reach the chemical recovery cycle. Using electrodialysis for selective NPE removal can prevent the problems caused by accumulation of inorganic NPEs in the pulping cycle and recovery boiler. In this work, acidic bleach plant filtrates from three mills using different bleaching sequences based on chlorine dioxide were characterized. The analyses showed no fundamental differences in the inorganic NPE composition or other characteristics among these filtrates. The majority of total dissolved solids in the effluents were found to be inorganic NPEs. Chloride and nitrate were present at significant levels in all effluent samples. Sodium was the predominant metal ion, while calcium and magnesium were also present at considerable levels. The feasibility of using electrodialysis to selectively remove inorganic NPEs from the acidic bleach effluent was successfully demonstrated in laboratory experiments with effluents from all these three mills. Although there were some variations in these effluents, chloride and potentially harmful cations, such as potassium, calcium, and magnesium, were removed efficiently from the bleach effluents into a small-volume, concentrated purge stream. This effective removal of

  4. Reduce, reuse and recycle

    CSIR Research Space (South Africa)

    Afrika, M

    2010-10-01

    Full Text Available The adoption of the internationally accepted waste management hierarchy (Sakai et al, 1996) into South African policy has changed the focus from “end of pipe” waste management towards waste minimisation (reuse, recycling and cleaner production...

  5. Glomerular filtration rate

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007305.htm Glomerular filtration rate To use the sharing features on this page, please enable JavaScript. Glomerular filtration rate (GFR) is a test used to check ...

  6. Water Reuse: Using Reclaimed Water For Irrigation

    OpenAIRE

    Haering, Kathryn; Evanylo, Gregory K.; Benham, Brian Leslie, 1960-; Goatley, Michael

    2009-01-01

    Describes water reuse and reclaimed water, explains how reclaimed water is produced, options for water reuse, water reuse regulations, and agronomic concerns with water reuse, and provides several case studies of water reuse.

  7. Cross-flow filtration and axial filtration

    International Nuclear Information System (INIS)

    Kraus, K.A.

    1974-01-01

    Two relatively novel alternative solid-liquid-separation techniques of filtration are discussed. In cross-flow filtration, the feed is pumped past the filtering surface. While in axial filtration the filter, mounted on a rotor, is moved with respect to the feed. While large-scale application of the axial filter is still in doubt, it permits with little expenditure of time and money, duplication of many hydrodynamic aspects of cross-flow filtration for fine-particle handling problems. The technique has been applied to municipal wastes, low-level radioactive waste treatment plant, lead removal from industrial wastes, removal of pulp-mill contaminants, textile-mill wastes, and pretreatment of saline waters by lime-soda process in preparation for hyperfiltration. Economics and energy requirements are also discussed

  8. Optimization of Bleaching Parameters for Soybean Oil

    Directory of Open Access Journals (Sweden)

    Tomislav Domijan

    2012-01-01

    Full Text Available The final stage of edible soybean oil manufacture is refining, the most delicate phase of which is bleaching. At this step, undesirable substances are removed, such as pigments, traces of metals, phospholipids and certain degradation products. However, certain valuable compounds such as tocopherols and sterols may also be removed, significant loss of oxidative stability can occur, and fatty acid content may increase. To avoid these negative oil changes, bleaching parameters such as the concentration of bleaching clay, temperature and duration should be optimized. Since bleaching conditions depend on the properties of the bleaching clay as well as on the type of crude oil, bleaching parameters should be optimized with different types of clay for each vegetable oil. Since such optimization has not yet been reported for soybean oil treated with Pure-Flo® Supreme Pro-Active bleaching adsorbent, this study investigates the effect of bleaching parameters on bleaching efficiency, oxidative stability and the content and composition of bioactive compounds (tocopherols and sterols using the above mentioned clay in this type of oil. Results show that the amount of clay had the greatest influence on bleaching efficiency, especially according to the Lovibond scale, on transparency, and on phosphorus content. Temperature and clay amount significantly affected oxidative stability, in particular the formation of secondary oxidation products. Increasing the amount of clay decreased tocopherol content of the bleached oil. Neutralized soybean oil bleached for 20 min at 95 °C with 1 % Pure-Flo® Supreme Pro-Active bleaching clay showed the highest oxidative stability, best bleaching efficiency, and most favourable sterol content, although tocopherol content was reduced.

  9. Use of Excel ion exchange equilibrium solver with WinGEMS to model and predict NPE distribution in the Mead/Westvaco Evandale, TX, hardwood bleach plant

    Science.gov (United States)

    Christopher Litvay; Alan Rudie; Peter Hart

    2003-01-01

    An Excel spreadsheet developed to solve the ion-exchange equilibrium in wood pulps has been linked by dynamic data exchange to WinGEMS and used to model the non-process elements in the hardwood bleach plant of the Mead/Westvaco Evandale mill. Pulp and filtrate samples were collected from the diffusion washers and final wash press of the bleach plant. A WinGEMS model of...

  10. THE EFFECT OF WATER REDUCTION IN KRAFT PULP WASHING IN ECF BLEACHING

    Directory of Open Access Journals (Sweden)

    Tânia Cristina Frigieri

    Full Text Available ABSTRACT The main objective of this work was to study the technical viability of using the cellulose bleaching effluent, at several stages of the process, seeking fresh water reduction in pulp washing, and evaluating its effect on pulp quality. Eucalyptus spp. industrial cellulosic pulp with oxygen was used in this experiment. The same bleaching sequence D(E+PDP was performed ten times, under the same conditions (temperature, consistency and time. Counter current washing was used in the bleaching stages, and each sequence was carried out with different washing factors: 9, 6, 3, 0 m3 of distilled water/ton of pulp, trying to reach brightness of 92 ± 0,5% ISO. The ten sequences sought to achieve the stability of the effluent organic load, measured by the chemical oxygen demand (COD. Then, the COD results were compared to the brightness ones from the bleached pulp. The evaluated results from the ten sequences and four different washings showed an increasing in COD due to the organic load accumulation, resulting from the reuse of effluent from previous sequences. This COD increasing provided the lower brightness results during the cycles, besides the water reduction, evidencing the necessity of washing between bleaching stages. In this study, the obtained result for the pulp washing up to 3m3/t was tolerable and even recommended. On the other hand, the pulp without any washing (0m3/t, due to the lack of enough brightness, it is commercially unviable.

  11. Beneficial reuse '97

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    The annual Beneficial Reuse Conference was conducted in Knoxville, Tennessee from August 5-7, 1997. Now in its fifth year, this conference has become the national forum for discussing the beneficial reuse and recycle of contaminated buildings, equipment and resources, and the fabrication of useful products from such resources. As in the past, the primary goal of Beneficial Reuse ''97 was to provide a forum for the practitioners of pollution prevention, decontamination and decommissioning, waste minimization, reindustrialization, asset management, privatization and recycling to share their successes and failures, as well as their innovative strategies and operational experiences with the assembled group of stakeholders. Separate abstracts have been indexed into the database for contributions to this conference proceedings

  12. 40 CFR 63.445 - Standards for the bleaching system.

    Science.gov (United States)

    2010-07-01

    ...) Bleaching systems bleaching pulp from kraft, sulfite, or soda pulping processes that use any chlorinated compounds; or (3) Bleaching systems bleaching pulp from mechanical pulping processes using wood or from any process using secondary or non-wood fibers, that use chlorine dioxide. (b) The equipment at each bleaching...

  13. Promoter reuse in prokaryotes

    NARCIS (Netherlands)

    Nijveen, H.; Matus-Garcia, M.; Passel, van M.W.J.

    2012-01-01

    Anecdotal evidence shows promoters being reused separate from their downstream gene, thus providing a mechanism for the efficient and rapid rewiring of a gene’s transcriptional regulation. We have identified over 4000 groups of highly similar promoters using a conservative sequence similarity search

  14. Assessment of the process of cottonseed oil bleaching in hexane

    Directory of Open Access Journals (Sweden)

    Megahed, Ola A.

    2002-12-01

    Full Text Available This work has been initiated to assess the feasibility of bleaching cottonseed oil in miscella as a processing step next to alkali refining in miscella. Alkali refining of cottonseed oil in miscella has several advantages over conventional refining technologies with respect to oil quality, oil losses and process cost. Therefore, the process efficiency of the bleaching of cottonseed oil in presence of hexane (at a volumetric ratio of 1:1, has been studied and compared to that without solvent. The process efficiency has been evaluated according to the decolourization capacity, the oil losses on spent earth, the filtration rate of the oil from the clay and the acidity of the bleached oil as well as its peroxide content. The bleaching in presence of hexane was carried out at 25ºC whereas that by conventional bleaching at 110ºC. Different clay loads were used in each of the two bleaching techniques and the colour indices of the oils before and after bleaching determined in each case. The results were used to predict Freundlich adsorption equations for the oil pigments in both cases. These equations were then used to predict the colour of the oils obtained by bleaching of refined oils of different grades. The results have shown that oil decolourization is more efficient in presence of solvent when the starting oil is of an acceptable grade and the reverse is true for low grade oils. Also, the possibility of oil oxidation during bleaching is less in presence of solvent. Moreover, the bleaching in miscella has proved two other additional advantages over conventional bleaching. The filtration of oil from clay is much faster in miscella bleaching and the oil losses on spent earth is lower. This will be reflected on the overall process economy.Este trabajo ha sido iniciado para evaluar la viabilidad de la decoloración del aceite de semilla de algodón en miscela como un paso de procesado próximo a la refinación alcalina en miscela. La refinaci

  15. Dentist-prescribed home bleaching: current status.

    Science.gov (United States)

    Dunn, J R

    1998-08-01

    White teeth have been an indicator of physical attractiveness throughout history. Only recently have we been able to whiten teeth with few side effects, making tooth bleaching a popular and effective dental treatment. The American Dental Association (ADA) has established guidelines on safety and effectiveness for tooth bleaching. External stains from aging or inherent dark color are more responsive to bleaching than internal stains. Dentist-prescribed home bleaching--including a careful dental exam, custom-fabricated trays, tacky high-viscosity gels, adequate instructions, and recall exams--has been shown to be an effective method for bleaching teeth. Trays can be worn overnight or during the day with similar effectiveness. The bleaching effect can last up to 3 years with more than 50% success.

  16. Patient Safety Threat - Syringe Reuse

    Science.gov (United States)

    ... to Prevent HAIs HICPAC One & Only Campaign A Patient Safety Threat – Syringe Reuse Recommend on Facebook Tweet Share Compartir Important ... due to syringe reuse by your healthcare provider. Patients need to be aware of a very serious ...

  17. Modeling chlorine dioxide bleaching of chemical pulp

    OpenAIRE

    Tarvo, Ville

    2010-01-01

    This doctoral thesis deals with the phenomenon-based modeling of pulp bleaching. Previous bleaching models typically utilize one or two empirical correlations to predict the kinetics in kappa number development. Empirical correlations are simple to develop, but their parameters are often tied to the validation system. A major benefit of physico-chemical phenomenon models is that they are valid regardless of the reaction environment. Furthermore, modeling the bleaching processes at molecular l...

  18. Measuring reuse in hazard analysis

    International Nuclear Information System (INIS)

    Hazard analysis for safety-critical systems require sufficient coverage and rigour to instill confidence that the majority of hazardous consequences have been identified. These requirements are commonly met through the use of exhaustive hazard analysis techniques. However, such techniques are time consuming and error-prone. As an attempt at exhaustive coverage, hazard analysts typically employ reuse mechanisms such as copy-and-paste. Unfortunately, if reuse is applied inappropriately there is a risk that the reuse is at the cost of rigour in the analysis. This potential risk to the validity of the analysis is dependent on the nature and amount of reuse applied. This paper investigates hazard analysis reuse over two case studies. Initially reuse in an existing safety argument is described. Argument structures within the hazard analysis are identified and the amount of verbatim reuse examined. A second study is concerned with how reuse changes as a result of tool support. In contrast to the first case, the defined arguments are more diverse-reuse has occurred but is less verbatim in nature. Although tool support has aided the customisation of the reused arguments, many are only trivially customised. An edit distance algorithm is utilised to identify and enumerate verbatim and trivial reuse in the arguments

  19. THE BLEACHING SYNDROME: MANIFESTATION OF A POST ...

    African Journals Online (AJOL)

    User

    exception, Western ideals are an environmental force that disrupts the well-being of African descended women in particular, resulting in the Bleaching Syndrome. Although the literature acknowledges racism among the list of colonial pathologies, amidst idealization of light skin neglect of the Bleaching Syndrome has been ...

  20. Microhardness of demineralized enamel following home bleaching and laser-assisted in office bleaching

    Science.gov (United States)

    Ghanbarzadeh, Majid; Akbari, Majid; Hamzei, Haniye

    2015-01-01

    Background There is little data regarding the effect of tooth whitening on microhardness of white spot lesions. This study was conducted to investigate the effect of home-bleaching and laser-assisted in-office bleaching on microhardness of demineralized enamel. Material and Methods Forty bovine incisors were selected and immersed in a demineralizing solution for 12 weeks to induce white spot lesions. Enamel blocks were prepared and randomly assigned to two groups of 20 each. The first group underwent home bleaching with 15% carbamide peroxide which was applied for 8 hours a day over a period of 15 days. In the second group, in-office bleaching was performed by 40% hydrogen peroxide and powered by irradiation from an 810 nm gallium-aluminum-arsenide (GaAlAs) diode laser (CW, 2W). This process was performed for 3 sessions every seven days, in 15 days. The specimens were stored in Fusayama Meyer artificial saliva during the experiment. Surface microhardness was assessed before and after the bleaching therapies in both groups. Results Microhardness decreased significantly following both home bleaching and laser-assisted in-office bleaching (p<0.05). There were no significant differences in hardness values among the two groups either before (p=0.131) or after (p=0.182) the bleaching procedures. Conclusions Tooth whitening through home bleaching or laser-assisted in-office bleaching can result in a significant reduction in microhardness of white spot lesions. Therefore, it is suggested to take protective measures on bleached demineralized enamel. Key words:White spot lesion, bleaching, laser, microhardness, demineralized enamel, home bleaching, in-office bleaching. PMID:26330939

  1. Filtration in Porous Media

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander

    There is a considerable and ongoing effort aimed at understanding the transport and the deposition of suspended particles in porous media, especially non-Fickian transport and non-exponential deposition of particles. In this work, the influential parameters in filtration models are studied...... to understand their effects on the non-Fickian transport and the non-exponential deposition. The filtration models are validated by the comparisons between the modelling results and the experimental data.The elliptic equation with distributed filtration coefficients may be applied to model non-Fickian transport...

  2. BLEACHING IN VITAL TEETH: A LITERARY REVIEW

    Directory of Open Access Journals (Sweden)

    Felipe Fagundes Soares

    2007-12-01

    Full Text Available Tooth bleaching technique has presented a significant evolution, promoting higher satisfaction and comfort to the patients. Therefore, the aim of this study was to present the bleaching agents and the techniques, discussing advantages and disadvantages of each one, and the effect of these agents in the oral environment. The main agents used in the bleaching technique are the hydrogen peroxide and the carbamide peroxide, promoting the bleaching effect through oxidation of organic compounds. The application of these agents can be made at home or at a doctor office. During treatment, it may occur some adverse effects, such as tooth sensibility, increasing of dental porosity, and some interactions with the restorative material. However, these adverse effects can be eliminated or controlled when the treatment is executed under professional orientation. When the bleaching technique is well indicated and correctly conducted, it is associated with significantly positive results.

  3. Membrane treatment of alkaline bleaching effluents from elementary chlorine free kraft softwood cellulose production.

    Science.gov (United States)

    Oñate, Elizabeth; Rodríguez, Edgard; Bórquez, Rodrigo; Zaror, Claudio

    2015-01-01

    This paper reports experimental results on the sequential use of ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) to fractionate alkaline extraction bleaching effluents from kraft cellulose production. The aim was to unveil the way key pollutants are distributed when subjected to sequential UF/NF/RO membrane separation processes. Alkaline bleaching effluents were obtained from a local pinewood-based mill, featuring elementary chlorine free bleaching to produce high-brightness cellulose. The experimental system was based on a laboratory-scale membrane system, DSS LabStak® M20 Alfa Laval, using Alfa Laval UF and NF/RO membranes, operated at a constant transmembrane pressure (6 bar for UF membranes and 32 bar for NF/RO membranes), at 25°C. Results show that 78% chemical oxygen demand (COD) and total phenols, 82% adsorbable organic halogens (AOX) and 98% colour were retained by UF membranes which have molecular weight cut-off (MWCO) above 10 kDa. In all, 16% of original COD, total phenols and AOX, and the remaining 2% colour were retained by UF membranes within the 1 to 10 kDa MWCO range. Chloride ions were significantly present in all UF permeates, and RO was required to obtain a high-quality permeate with a view to water reuse. It is concluded that UF/NF/RO membranes offer a feasible option for water and chemicals recovery from alkaline bleaching effluents in kraft pulp production.

  4. PROBLEMS OF NONSTATIONARY FILTRATION

    Directory of Open Access Journals (Sweden)

    Vsevolod A. Shabanov

    2018-03-01

    Full Text Available he article deals with the classical hydrodynamic theory of filtration. Discusses models of soil, fluid and nature of fluid flow that formed the basis for the creation of the classic filtration theory. Also discusses the assumptions made for the linearization of the equations. Evaluated the scope of the classical filtration theory. Proposed a new model of filtration through a porous medium, based on the application of the laws of theoretical mechanics. It is based on the classical model of soil: the soil is composed of capillaries with ..parallel axes, in which the liquid moves. For tasks of infiltration equations of motion. Considered special cases of unsteady motion of a finite volume of liquid. Numerical example a machine experiment.

  5. Mill Designed Bio bleaching Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Institute of Paper Science Technology

    2004-01-30

    A key finding of this research program was that Laccase Mediator Systems (LMS) treatments on high-kappa kraft could be successfully accomplished providing substantial delignification (i.e., > 50%) without detrimental impact on viscosity and significantly improved yield properties. The efficiency of the LMS was evident since most of the lignin from the pulp was removed in less than one hour at 45 degrees C. Of the mediators investigated, violuric acid was the most effective vis-a-vis delignification. A comparative study between oxygen delignification and violuric acid revealed that under relatively mild conditions, a single or a double LMS{sub VA} treatment is comparable to a single or a double O stage. Of great notability was the retention of end viscosity of LMS{sub VA} treated pulps with respect to the end viscosity of oxygen treated pulps. These pulps could then be bleached to full brightness values employing conventional ECF bleaching technologies and the final pulp physical properties were equal and/or better than those bleached in a conventional ECF manner employing an aggressively O or OO stage initially. Spectral analyses of residual lignins isolated after LMS treated high-kappa kraft pulps revealed that similar to HBT, VA and NHA preferentially attack phenolic lignin moieties. In addition, a substantial decrease in aliphatic hydroxyl groups was also noted, suggesting side chain oxidation. In all cases, an increase in carboxylic acid was observed. Of notable importance was the different selectivity of NHA, VA and HBT towards lignin functional groups, despite the common N-OH moiety. C-5 condensed phenolic lignin groups were overall resistant to an LMS{sub NHA, HBT} treatments but to a lesser extent to an LMS{sub VA}. The inactiveness of these condensed lignin moieties was not observed when low-kappa kraft pulps were biobleached, suggesting that the LMS chemistry is influenced by the extent of delignification. We have also demonstrated that the current

  6. [Assessment of tooth bleaching efficacy with spectrophotometer].

    Science.gov (United States)

    Zhu, Wenhao; Liu, Chang; Pan, Jie

    2014-06-01

    To analyze the changes in CIE L*, a*, and b* at cervical, body, and incisal sites after tooth bleaching by using a spectrophotometer. Sixty-seven intact and healthy maxillary central incisors were in-vestigated. These incisors were darker than A3 according to the Vita Classical shade guide. The CIE tooth shade parameters L*, a*, and b* were simultaneously recorded at three tooth areas (cervical, body, and incisal) with a spectrophotometer before and after tooth bleaching (35%H2O2 coordinating with Beyond whitening accelerator irradiating). The shade dif-ferential (DeltaE) was calculated. ANOVA, paired t-test, and Pearson correlation analysis were used for data analysis. The efficacy rates of tooth bleaching were satisfactory, with 86.6%, 86.6%, and 85.1% in the cervical, body, and incisal sites, respectively. The average values of DeltaE were 5.09, 4.44, and 4.40 in the cervical, body, and incisal sites. Tooth bleaching significantly increased L* and significantly decreased a* and b* in all tooth areas (P spectrophotometer could objectively evaluate the whitening effect of tooth bleaching at the different tooth sites. The tooth bleaching system (35%H202 coordinating with Beyond whitening accelerator irradiating) exerts powerful bleaching actions in most of the tooth areas investigated. The order of tooth bleaching effectiveness is cervicalbody>incisal. Yellow coloration is decreased mainly at the cervical site, and brightness was increased mostly at theincisal site. The effectiveness of tooth bleaching increases as the baseline b* value increases.

  7. COOPERATIVE LAND REUSE PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    1999-07-30

    The objective of this study was to determine what financial return, if any, DOE would realize if they invest solely in removal of the asbestos from these three Hanford steam plants and the associated large bore distribution piping at the site. Once the asbestos was removed the strategy was to bring in companies that specialize in salvage and material re-use and have them remove, at no cost to DOE, the plants and the associated large bore piping. The salvage companies we contacted had said that if they didn't have to remove asbestos, they may be able to realize enough value from these plants to offset their demolition and/or dismantling cost. The results were not what we expected but they do offer DOE some favorable financial alternatives to their present approach. The study concluded that there was very little salvage and/or re-use value remaining in the steam plant material that could be used to offset the demolition and/or dismantling cost. The notable exception to this is the removal of the 24 inch steam piping that runs from 200E to 200W areas (see IDM executive summary under Dismantling cost). It is estimated that the re-use value of the 24-inch piping would more than pay for the dismantling cost of this piping. On a more favorable note, it does appear as though the cost of conventional demolition can be reduced by a factor of 3 to 5 if the asbestos is removed first and the demolition is performed using competitive and commercial practices. Both estimates in this study are similar except that IDM did not include floor slab removal nor remove the same quantity of piping. This is why we are using a range of 3 to 5 as a reduction factor. The IDM estimate (using union labor) for demolition after removal of asbestos was approximately $1.5M versus $10.0M for accomplishing the work using Hanford practices and rates.

  8. Can marine cloud brightening reduce coral bleaching?

    OpenAIRE

    Latham, J; Kleypas, J; Hauser, R; Parkes, B; Gadian, A

    2013-01-01

    Increases in coral bleaching events over the last few decades have been largely caused by rising sea surface temperatures (SST), and continued warming is expected to cause even greater increases through this century. We use a Global Climate Model to examine the potential of marine cloud brightening (MCB) to cool oceanic surface waters in three coral reef provinces. Our simulations indicate that under doubled CO conditions, the substantial increases in coral bleaching conditions from current v...

  9. Water Treatment Technology - Filtration.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on filtration provides instructional materials for six competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: purposes of sedimentation basins and flocculation…

  10. Alternative bleaching methods for Cheddar cheese whey.

    Science.gov (United States)

    Kang, E J; Smith, T J; Drake, M A

    2012-07-01

    Residual annatto colorant (norbixin) in fluid Cheddar cheese whey can be bleached. The 2 approved chemical bleaching agents for whey, hydrogen peroxide (HP) and benzoyl peroxide (BP), negatively impact the flavor of dried whey protein. The objective of this study was to evaluate alternative methods for bleaching liquid whey: ultraviolet radiation (UV), acid-activated bentonite (BT), and ozone (OZ). Colored Cheddar cheese whey was manufactured followed by pasteurization and fat separation. Liquid whey was subjected to one of 5 treatments: control (CT) (no bleaching; 50 °C, 1 h), HP (250 mg/kg; 50 °C, 1 h), UV (1 min exposure; 50 °C), BT (0.5% w/w; 50 °C, 1 h), or OZ (2.2g/h, 50 °C, 1 h). The treated whey was then ultrafiltered, diafiltered, and spray-dried to 80% whey protein concentrate (WPC80). The entire experiment was replicated 3 times. Color (norbixin extraction and measurement), descriptive sensory, and instrumental volatile analyses were conducted on WPC80. Norbixin elimination was 28%, 79%, 39%, and 15% for HP, BT, UV, and OZ treatments, respectively. WPC80 from bleached whey, regardless of bleaching agent, had lower sweet aromatic and cooked/milky flavors compared to unbleached CT (P < 0.05). The HP and BT WPC80 had higher fatty flavor compared to the CT WPC80 (P < 0.05), and the UV and OZ WPC80 had distinct mushroom/burnt and animal flavors. Volatile compound results were consistent with sensory results and confirmed higher relative abundances of volatile aldehydes in UV, HP, and OZ WPC80 compared to CT and BT WPC80. Based on bleaching efficacy and flavor, BT may be an alternative to chemical bleaching of fluid whey. The 2 approved chemical bleaching agents for whey, hydrogen peroxide (HP) and benzoyl peroxide (BP), negatively impact flavor of dried whey protein, and restrictions on these agents are increasing. This study evaluated 3 alternatives to chemical bleaching of fluid whey: UV radiation, ozone, and bentonite. © 2012 Institute of Food

  11. Temperament and perception of tooth bleaching results

    Directory of Open Access Journals (Sweden)

    Katarzyna Mehr

    2016-09-01

    Full Text Available Background . The neurophysiological process of perceiving the results of tooth bleaching requires the correct interaction between the central nervous system and the organs of sight. Exaggerated beliefs concerning defective facial features may enhance inner attitudes about one’s own color of dentition, as well as a feeling of dissatisfaction with the degree of leaching. Objectives. The study aimed to assess the degree of the patient satisfaction with the results of tooth bleaching in relation to their temperament. Material and methods. There were 68 generally healthy volunteers, aged 28–38 years, with external discolorations of the teeth. They had never undergone dental bleaching and their frontal teeth did not have any fillings. After clinical evaluation and the completion of formalities, the patients were asked to fill in Strelau’s temperament questionnaire. Questionnaires and visual status were assessed three times by three doctors: before bleaching, and then 24 hours and two weeks after the home-bleaching operation, which was done with the use of Opalescence (Ultradent in uniform sequence. Results . There were practically no adverse side results, except a periodic dentin hypersensitivity that occurred periodically in 44 patients. The results of the visual assessment performed by the physicians did not differ. The questionnaire data showed that women were more critical of the results in relation to the expectations. Among elancholics, full satisfaction was declared by 41%, whereas among sanguine people, full satisfaction was obtained by 85%. Satisfaction with the aesthetic results was associated with bleaching by at least 4 degrees. Conclusions . Patients’ temperament affects their subjective evaluation of the effectiveness of tooth bleaching, which should be taken into consideration in the patient’s individual dental treatment plan.

  12. Combined Bleaching Technique Using Low and High Hydrogen Peroxide In-Office Bleaching Gel.

    Science.gov (United States)

    Rezende, M; Ferri, L; Kossatz, S; Loguercio, A D; Reis, A

    2016-01-01

    The aim of this study was to evaluate the efficacy, color stability, risk, and intensity of tooth sensitivity (TS) of combined bleaching techniques performed with 20% or 35% hydrogen peroxide for an in-office protocol. Thirty patients were randomly divided into two groups and submitted to a single 45-minute in-office bleaching session with 35% hydrogen peroxide or 20% hydrogen peroxide. At-home bleaching was performed with 10% carbamide peroxide for two hours daily over the course of two weeks. The color was evaluated with the value-oriented shade guide Vita Classical at different periods up to 12 months after bleaching. Patients recorded the intensity of TS using a five-point verbal scale. Color change data were submitted to a two-way repeated-measures analysis of variance and Tukey test (α=0.05). The absolute risk and intensity of TS were compared with the Fisher exact test and Mann-Whitney test, respectively (α=0.05). On average, an effective and similar whitening of three units in shade guide was observed for both groups, which remained stable for 12 months. When both protocols were compared, the one with hydrogen peroxide 35% showed a higher risk (p=0.02) and intensity of TS (p=0.04). In regard to the TS intensity, no significant difference was observed up to 48 hours after in-office bleaching (p=0.09) and during the at-home bleaching phase of the study (p=0.71). The combined bleaching technique using at-home bleaching associated with in-office bleaching was effective and stable over the course of 12 months, regardless of the concentration of the hydrogen peroxide used for in-office bleaching. However, the protocol with 20% hydrogen peroxide produced lower risk and intensity of TS.

  13. Comparison between traditional and laser bleaching treatment

    Science.gov (United States)

    Cesar, Ilene C. R.; Redigolo, Marcela L.; Liporoni, Priscila C. S.; Munin, Egberto

    2001-10-01

    Fifteen human embedded third molars were used in this in vitro study to evaluate the effects of two bleaching products associated or not with Argon laser application. The samples received a cervical-apical cut and were longitudinally cut into 4 parts resulting in 75 specimens. These parts were divided at random into 5 groups and submitted to the traditional power bleaching procedure for enamel. Group 1 was separated as a control group. Group 2 was exposed to 37 % carbamide peroxide bleaching solution and developed with an Argon laser application. The same solution was used in Group 3 but the bleaching was developed with an halogen lamp irradiation. 35 % carbamide peroxide were used in Groups 4 and 5. One was developed as Group 2 and the other as Group 3. The samples were analyzed under a photoreflectance experiment. We observed that Group 2 presented more white spectra than Group 3. However, Groups 4 and 5 showed the same results independent of the use of the laser or the halogen lamp for the light curing. Comparing both bleaching products, the 35 % carbamide peroxide was more efficient on its purposes than the other one.

  14. A Chemical Approach to Mitigate Coral Bleaching

    Science.gov (United States)

    Marty-Rivera, M.; Yudowski, G.

    2016-02-01

    Changes in sea surface temperature and irradiance can induce bleaching and increase mortality in corals. Coral bleaching occurs when symbiotic algae living inside the coral is degraded or expelled, reducing the availability of energetic resources. Oxidative stress has been suggested as a possible molecular mechanism triggering bleaching. We hypothesized that reduction of reactive oxygen species (ROS) during stress could mitigate or prevent coral bleaching. We utilized the coral Porites Astreoides as our model to test the effects of two natural antioxidants, catechin and Resveratrol, on thermally induced bleaching. Coral fragments were exposed to four treatments: high temperature (32°C), high temperature plus antioxidants (1μM), ambient temperature (25°C), or ambient temperature (25°C) plus antioxidant for four days. A total of 8 corals were used per treatment. We measured several photobiological parameters, such as maximum quantum yield and light curves to assess the viability of symbiodinium spp. after thermal stress in the presence of antioxidants. Preliminary experiments on a model species, the sea anemone Aiptasia pallida and corals, showed that exposure to antioxidants reduced intracellular levels of ROS. Additionally, antioxidant-treated anemones showed higher photosynthetic efficiency (67%) than those exposed to high-temperature alone.

  15. Mixture based outlier filtration

    Czech Academy of Sciences Publication Activity Database

    Pecherková, Pavla; Nagy, Ivan

    2006-01-01

    Roč. 46, č. 2 (2006), s. 30-35 ISSN 1210-2709 R&D Projects: GA MŠk 1M0572; GA MDS 1F43A/003/120 Institutional research plan: CEZ:AV0Z10750506 Keywords : data filtration * system modelling * mixture models Subject RIV: BD - Theory of Information http://library.utia.cas.cz/prace/20060165.pdf

  16. Bleach boosting effect of xylanase A from Bacillus halodurans C-125 in ECF bleaching of wheat straw pulp.

    Science.gov (United States)

    Lin, Xiao-qiong; Han, Shuang-yan; Zhang, Na; Hu, Hui; Zheng, Sui-ping; Ye, Yan-rui; Lin, Ying

    2013-02-05

    Past studies have revealed major difficulties in applications of xylanase in the pulp and paper industry as enzymes isolated from many different species could not tolerate high temperatures or highly alkaline conditions. The thermostable xylanase A from Bacillus halodurans C-125 (C-125 xylanase A) was successfully cloned and expressed in Pichia pastoris with a yield as high as 3361 U/mL in a 2 L reactor. Its thermophilic and basophilic properties (optimal activity at 70 °C and pH 9.0), together with the fact it is cellulase-free, render this enzyme attractive for compatible applications in the pulp and paper industry. The pretreatment of wheat straw pulp with C-125 xylanase A at pH 9.0 and 70 °C for 90 min induced the release of both chromophores (Ab(237), Ab(254), Ab(280)) and hydrophobic compounds (Ab(465)) into the filtrate as well as sugar degradation. Moreover, the addition of 10 U xylanase to 1 g wheat straw pulp (dry weight) as pretreatment improved brightness by 5.2% ISO and decreased the kappa number by 5.0% when followed by hydrogen peroxide bleaching. In addition, compared with two commercial enzymes, Pulpzyme HC and AU-PE89, which are normally incorporated in ECF bleaching of wheat straw pulp, C-125 xylanase A proved to be more effective in enhancing brightness as well as preserving paper strength properties. When evaluating the physical properties of pulp samples, such as tensile index, tearing index, bursting index, and post-color (PC) number, the enzymes involved in pretreating pulps exhibited better or the same performances as chemical treatment. Compared with chemical bleaching, chlorine consumption can be significantly reduced by 10% for xylanase-pretreated wheat straw pulp while maintaining the brightness together with the kappa number at the same level. Scanning electron microscopy revealed significant surface modification of enzyme-pretreated pulp fibers with no marked fiber disruptions. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. On luminescence bleaching of tidal channel sediments

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Pejrup, Morten; Murray, Andrew S.

    2015-01-01

    We investigate the processes responsible for bleaching of the quartz OSL signal from tidal channel sediment. Tidal dynamics are expected to play an important role for complete bleaching of tidal sediments. However, no studies have examined the amount of reworking occurring in tidal channels...... and on tidal flats due to the mixing caused by currents and waves. We apply bed level data to evaluate the amount of vertical sediment reworking in modern tidal channels and at a tidal flat. Cycles of deposition and erosion are measured with a bed level sensor, and the results show that gross sedimentation...... was several times higher than net sedimentation. We propose that tidal channel sediment is bleached either on the tidal flat before it is transported to the tidal channels and incorporated in channel-fill successions or, alternatively, on the shallow intertidal part of the channel banks. Based...

  18. Side effects of external tooth bleaching

    DEFF Research Database (Denmark)

    Bruzell, E.M.; Pallesen, Ulla; Thoresen, N.R.

    2013-01-01

    Objective The study was performed to assess the risk of at-home and in-office bleaching procedures, and to recognise potential predictors for side effects. Design Multi-centre, questionnaire-based prospective study with follow-ups at around 14 days and around one year post-treatment. Setting......-office = 39.3% [n = 28]; p >0.05; 95% CI [OR]: 0.198‑1.102) whereas prevalence of gingival irritation was higher after in-office treatment (at-home = 14.0%; in-office = 35.7%; p effects...... attributed to the bleaching treatment in the at-home and in-office groups, respectively. Predictors for side effects were tooth sensitivity, surface loss and gingivitis when observed at inclusion. Treatment-related predictors were bleaching concentration and contact between tray and gingiva. Conclusions...

  19. Short communication: The influence of solids concentration and bleaching agent on bleaching efficacy and flavor of sweet whey powder.

    Science.gov (United States)

    Jervis, M G; Smith, T J; Drake, M A

    2015-04-01

    Recent studies have demonstrated the effect of bleaching conditions and bleaching agent on flavor and functional properties of whey protein ingredients. Solids concentration at bleaching significantly affected bleaching efficacy and flavor effects of different bleaching agents. It is not known if these parameters influence quality of sweet whey powder (SWP). The purpose of this study was to determine the effects of solids concentration and bleaching agent on the flavor and bleaching efficacy of SWP. Colored cheddar whey was manufactured, fat separated, and pasteurized. Subsequently, the whey (6.7% solids) was bleached, concentrated using reverse osmosis (RO) to 14% solids, and then spray dried, or whey was concentrated before bleaching and then spray dried. Bleaching treatments included a control (no bleaching, 50 °C, 60 min), hydrogen peroxide (HP; 250 mg/kg, 50 °C, 60 min), benzoyl peroxide (50 mg/kg, 50 °C, 60 min), lactoperoxidase (20 mg/kg of HP, 50 °C, 30 min), and external peroxidase (MaxiBright, DSM Food Specialties, Delft, the Netherlands; 2 dairy bleaching units/mL, 50 °C, 30 min). The experiment was repeated in triplicate. Sensory properties and volatile compounds of SWP were evaluated by a trained panel and gas chromatography-mass spectrometry, respectively. Bleaching efficacy (norbixin destruction) and benzoic acid were measured by HPLC. Differences in bleaching efficacy, sensory and volatile compound profiles, and benzoic acid were observed with different bleaching agents, consistent with previous studies. Solids concentration affected bleaching efficacy of HP, but not other bleaching agents. The SWP from whey bleached with HP or lactoperoxidase following RO had increased cardboard and fatty flavors and higher concentrations of lipid oxidation compounds compared with SWP from whey bleached before RO. The SWP bleached with benzoyl peroxide after RO contained less benzoic acid than SWP from whey bleached before RO. These results indicate that

  20. Effect of RenNew-D as a sterilant on the performance of reused dialyzers.

    Science.gov (United States)

    Gagnon, R F; Adkar, V; Kaye, M

    1986-12-01

    RenNew-D (Alcide), a novel demand-release sporocidal agent, was employed instead of formaldehyde in the reprocessing for reuse of cuprophan hollow fiber dialyzers (Gambro) and the performance of these dialyzers was evaluated over 40 consecutive dialyses in six patients on maintenance hemodialysis. When RenNew-D was part of automated reprocessing performed with 4.3% bleach as specified by the manufacturer (Lixivitron), dialyzer survival was prolonged (16.7 +/- 7.2 uses) and hemodialysis neutropenia was unchanged with reuse. When RenNew-D was part of manual reprocessing conducted in the absence of bleach, marked improvement in dialyzer biocompatibility was observed but with a decreased survival (4.8 +/- 3.0). The majority of dialyzer failures were due to a fall in fiber bundle volume below a 85% set limit. Small solute clearances were maintained with both types of reprocessing. Dialyses were well tolerated throughout. Our data suggest that RenNew-D is a safe and efficacious product which can serve as a valuable alternative to formaldehyde for the purpose of dialyzer reuse.

  1. Tooth Bleaching: Current Concepts of the Procedure in Cosmetic ...

    African Journals Online (AJOL)

    Less caustic agents more recently introduced, in the late 1900s, have revived the interest of the dental profession in the art of tooth bleaching. These agents are now being packaged as bleaching kits, which may be used for in-office bleaching by the dentist or used at home by the patient under the supervision of the dentist.

  2. Bond strength of resin composite to light activated bleached enamel

    African Journals Online (AJOL)

    2015-09-02

    Sep 2, 2015 ... Conclusion: The various irradiation treatments following the application of the whiteness HP bleaching agent to enamel did not significantly reduce the µTBS within a 14‑day period. Key words: Bleaching agents, lasers, lasers neodymium: yttrium aluminum garnet, resin bonding, tooth bleaching. Date of ...

  3. Centralised urban stormwater harvesting for potable reuse.

    Science.gov (United States)

    McArdle, P; Gleeson, J; Hammond, T; Heslop, E; Holden, R; Kuczera, G

    2011-01-01

    Urban impervious areas provide a guaranteed source of runoff, especially in cities with high rainfall - this represents a source of water with low sensitivity to unfavourable climate change. Whilst the potential to reuse stormwater has long been recognised, its quality has largely limited usage to non-potable applications requiring the use of a third-pipe network, a prohibitively expensive option in established urban areas. Given recent advances in membrane filtration, this study investigates the potential of harvesting and treating stormwater to a potable standard to enable use of the potable distribution network. A case study based on the Throsby Creek catchment in Newcastle explores the issue. The high seasonally uniform rainfall provides insight into the maximum potential of such an option. Multicriterion optimisation was used to identify Pareto optimal solutions for harvesting, storing and treating stormwater. It is shown that harvesting and treating stormwater from a 13 km² catchment can produce yields ranging from 8.5 to 14.2 ML/day at costs ranging from AU$2.60/kL to AU$2.89/kL, which may become viable as the cost of traditional supply continues to grow. However, there are significant social impacts to deal with including alienation of public land for storage and community acceptance of treated stormwater.

  4. [Scalp burns induced by hair bleaching].

    Science.gov (United States)

    Bouschon, P; Bursztejn, A-C; Waton, J; Brault, F; Schmutz, J-L

    2018-03-14

    Hair bleaching is increasingly being carried out in hairdressing salons. The products used are a mixture of hydrogen peroxide and persulfates, both active chemical agents. Scalp burns secondary to hair bleaching are a traumatic adverse effect rarely discussed in publications that continue to be little known among healthcare professionals. We report the case of a 15-year-old girl with a plaque of scarring alopecia on the vertex. This lesion resulted from a deep burn following a hair-bleaching procedure. Healing took around 4 months, resulting in discomfort for our patient. This is a rare case of scarring alopecia following a basic chemical burn to the scalp. The oxidation reaction induced by the mixture of hydrogen peroxide and persulfates, prepared in a basic medium, causes bleaching of the melanin pigments in hair. The clinical presentation of a single, well limited, painful, oozing ulceration located at the vertex was similar to the other cases published in the literature. Although a chemical burning mechanism is most often incriminated, the procedure is always coupled with use of a heat source and associated thermal burn may occur. The delayed appearance of the lesion appears to be caused by the forming of surfactants by the hydrogen peroxide/persulfate mixture, resulting in slow dissolution of the oxidizing compounds within the stratum corneum. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  5. ADSORPTION ON HEAT REGENERATED SPENT BLEACHING ...

    African Journals Online (AJOL)

    Preferred Customer

    KINETICS AND THERMODYNAMICS OF AQUEOUS Cu(II) ADSORPTION ON. HEAT REGENERATED SPENT BLEACHING EARTH. Enos W. Wambu1*, Gerald K. Muthakia2*, Joseph K. wa-Thiong'o1 and Paul M. Shiundu3. 1Department of Chemistry, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya.

  6. Bleaching of the discolored traumatized tooth

    DEFF Research Database (Denmark)

    Dahl, Jon E.; Kopperud, Siemen E.; Pallesen, Ulla

    2018-01-01

    This chapter focuses on the treatment of discolored traumatized teeth, most of them being non-vital and subsequently, endodontically treated. Tooth bleaching based upon hydrogen peroxide as the active agent, applied directly or produced in a chemical reaction from sodium perborate or carbamide pe...

  7. Theoretical information reuse and integration

    CERN Document Server

    Rubin, Stuart

    2016-01-01

    Information Reuse and Integration addresses the efficient extension and creation of knowledge through the exploitation of Kolmogorov complexity in the extraction and application of domain symmetry. Knowledge, which seems to be novel, can more often than not be recast as the image of a sequence of transformations, which yield symmetric knowledge. When the size of those transformations and/or the length of that sequence of transforms exceeds the size of the image, then that image is said to be novel or random. It may also be that the new knowledge is random in that no such sequence of transforms, which produces it exists, or is at least known. The nine chapters comprising this volume incorporate symmetry, reuse, and integration as overt operational procedures or as operations built into the formal representations of data and operators employed. Either way, the aforementioned theoretical underpinnings of information reuse and integration are supported.

  8. In-Office Bleaching During Orthodontic Treatment.

    Science.gov (United States)

    Gomes, Mauricio Neves; Dutra, Hélio; Morais, Alexandre; Sgura, Ricardo; Devito-Moraes, André Guaraci

    2017-04-01

    To demonstrate that it is possible to pursue teeth whitening treatment protocols during orthodontic treatment with no esthetic loss. Many patients undergoing orthodontic treatment desire to have a straight and well aligned dentition, but also whiter teeth. For many years, it was believed that carrying out a whitening treatment with positioned orthodontic brackets in place would result in localized spots on the enamel labial surfaces of teeth. However, a deeper understanding of the bleaching process suggests that the oxidation caused by products, which results from hydrogen peroxide decomposition, are able to diffuse peripherally into the tooth structure and reach even that under the cemented brackets. Two in-office-bleaching treatments were performed in patients using orthodontic fixed braces in two or three 40-minute sessions using a 35% hydrogen peroxide. In-office bleaching is possible and effective, even with orthodontic brackets in position. The teeth were successfully bleached despite the presence of brackets. All biological criteria have been fulfilled satisfying patients' expectations of aligned and whitened teeth in less time than if treatments had been performed separately, with satisfactory results and no esthetic loss. The whitening of teeth is possible during orthodontic treatment with fixed braces without any esthetic loss. The in-office bleaching treatment with brackets in position also may act as a motivation factor, preventing patient withdrawal or treatment interruption. Therefore, at the end of the orthodontic treatment, the patient is able to display an aligned, functional and whitened smile. (J Esthet Restor Dent 29:83-92, 2017). © 2016 Wiley Periodicals, Inc.

  9. Latest aspects of mechanical filtration

    OpenAIRE

    Stanislav Koláček; Michal Černý

    2013-01-01

    The aim of this study was to describe and unify all knowledge about mechanic filtration. The first part deals with the parameters and properties of filtration. Here some important basic concepts are explained such as pressure gradient, filter life, etc. There’s also a description of convenient filtration technology for coarse and fine materials, such as sand, smoke or soot. The second part primarily focuses on the real use and application of filters for liquid and gaseous media. The differenc...

  10. Global warming and recurrent mass bleaching of corals.

    Science.gov (United States)

    Hughes, Terry P; Kerry, James T; Álvarez-Noriega, Mariana; Álvarez-Romero, Jorge G; Anderson, Kristen D; Baird, Andrew H; Babcock, Russell C; Beger, Maria; Bellwood, David R; Berkelmans, Ray; Bridge, Tom C; Butler, Ian R; Byrne, Maria; Cantin, Neal E; Comeau, Steeve; Connolly, Sean R; Cumming, Graeme S; Dalton, Steven J; Diaz-Pulido, Guillermo; Eakin, C Mark; Figueira, Will F; Gilmour, James P; Harrison, Hugo B; Heron, Scott F; Hoey, Andrew S; Hobbs, Jean-Paul A; Hoogenboom, Mia O; Kennedy, Emma V; Kuo, Chao-Yang; Lough, Janice M; Lowe, Ryan J; Liu, Gang; McCulloch, Malcolm T; Malcolm, Hamish A; McWilliam, Michael J; Pandolfi, John M; Pears, Rachel J; Pratchett, Morgan S; Schoepf, Verena; Simpson, Tristan; Skirving, William J; Sommer, Brigitte; Torda, Gergely; Wachenfeld, David R; Willis, Bette L; Wilson, Shaun K

    2017-03-15

    During 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.

  11. Global warming and recurrent mass bleaching of corals

    Science.gov (United States)

    Hughes, Terry P.; Kerry, James T.; Álvarez-Noriega, Mariana; Álvarez-Romero, Jorge G.; Anderson, Kristen D.; Baird, Andrew H.; Babcock, Russell C.; Beger, Maria; Bellwood, David R.; Berkelmans, Ray; Bridge, Tom C.; Butler, Ian R.; Byrne, Maria; Cantin, Neal E.; Comeau, Steeve; Connolly, Sean R.; Cumming, Graeme S.; Dalton, Steven J.; Diaz-Pulido, Guillermo; Eakin, C. Mark; Figueira, Will F.; Gilmour, James P.; Harrison, Hugo B.; Heron, Scott F.; Hoey, Andrew S.; Hobbs, Jean-Paul A.; Hoogenboom, Mia O.; Kennedy, Emma V.; Kuo, Chao-Yang; Lough, Janice M.; Lowe, Ryan J.; Liu, Gang; McCulloch, Malcolm T.; Malcolm, Hamish A.; McWilliam, Michael J.; Pandolfi, John M.; Pears, Rachel J.; Pratchett, Morgan S.; Schoepf, Verena; Simpson, Tristan; Skirving, William J.; Sommer, Brigitte; Torda, Gergely; Wachenfeld, David R.; Willis, Bette L.; Wilson, Shaun K.

    2017-03-01

    During 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching, the third global-scale event since mass bleaching was first documented in the 1980s. Here we examine how and why the severity of recurrent major bleaching events has varied at multiple scales, using aerial and underwater surveys of Australian reefs combined with satellite-derived sea surface temperatures. The distinctive geographic footprints of recurrent bleaching on the Great Barrier Reef in 1998, 2002 and 2016 were determined by the spatial pattern of sea temperatures in each year. Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. Consequently, immediate global action to curb future warming is essential to secure a future for coral reefs.

  12. Tangential filtration technologies membrane and applications for the industry agribusiness

    International Nuclear Information System (INIS)

    Leone, Gian Paolo; Russo, Claudio

    2015-01-01

    The membrane tangential filtration technologies are separation techniques based on the use of semipermeable filters through which, under a pushing force, it is possible to achieve separation of components or suspended in solution as a function of their dimensional characteristics and / or chemical-physical. At the laboratories of the ENEA Research Center Casaccia, as part of the program activities of the Biotechnology and agro-industry division, were studied and developed various filtration processes to membrane in the food industry. The problems have been studied by following a vision sustainable overall, always trying to pair the purification treatment to that of recovery and reuse of water and high value-added components. Ultimate goal of the research conducted is to close the production circuit, ensuring a discharge cycle zero and turning in fact a so-called spread in first, from which to obtain new products. [it

  13. Water Reuse and Pathogen Tracking

    Science.gov (United States)

    Building product water. By designing our buildings to collect and treat water generated on-site, can be and reused for flushing our toilets and irrigating our landscaping. Several water sources are generated with-in a building including: rainwater, stormwater, graywater, blackwa...

  14. The reuse of treated wood

    Science.gov (United States)

    Robert L. Smith; David Bailey; Delton R. Alderman; Philip A. Araman

    2006-01-01

    The primary goals of this book chapter are to identify barriers to the reuse of treated lumber, to describe the physical properties of spent chromated copper arsenate (CCA)-treated lumber coming from residential decks and to identify potential products and markets that can use spent treated lumber. The primary focus will be on CCA-treated lumber because it has been the...

  15. Filtration properties of nonwovens.

    Science.gov (United States)

    Gador, W; Jankowska, E

    1999-01-01

    This paper presents the results and conclusions from experimental investigations concerning filtration properties of nonwovens. The needled nonwovens were made from polyester fibres (PTE) with average fibre diameter 12 micrometres and polypropylene fibres (PP) with average fibre diameter 32 micrometres. Nonwovens were produced out of each of those fibres or out of a mixture of polyester and polypropylene fibres. This paper also presents investigations of nonwoven fabric made of polypropylene fibres (PP) with average fibre diameter 2.6 micrometres, which was formed according to melt-blown technology. Oil mist, as challenge aerosol, was used to evaluate the performance of filter media at various aerosol velocities. The average oil mist test aerosol particle diameter was 0.3 micrometre. Filter penetration was measured at oil mist concentration 0.24 g/m(3).

  16. Air filtration in HVAC systems

    CERN Document Server

    Ginestet, Alain; Tronville, Paolo; Hyttinen, Marko

    2010-01-01

    Air filtration Guidebook will help the designer and user to understand the background and criteria for air filtration, how to select air filters and avoid problems associated with hygienic and other conditions at operation of air filters. The selection of air filters is based on external conditions such as levels of existing pollutants, indoor air quality and energy efficiency requirements.

  17. Attitudes and norms affecting scientists' data reuse.

    Science.gov (United States)

    Curty, Renata Gonçalves; Crowston, Kevin; Specht, Alison; Grant, Bruce W; Dalton, Elizabeth D

    2017-01-01

    The value of sharing scientific research data is widely appreciated, but factors that hinder or prompt the reuse of data remain poorly understood. Using the Theory of Reasoned Action, we test the relationship between the beliefs and attitudes of scientists towards data reuse, and their self-reported data reuse behaviour. To do so, we used existing responses to selected questions from a worldwide survey of scientists developed and administered by the DataONE Usability and Assessment Working Group (thus practicing data reuse ourselves). Results show that the perceived efficacy and efficiency of data reuse are strong predictors of reuse behaviour, and that the perceived importance of data reuse corresponds to greater reuse. Expressed lack of trust in existing data and perceived norms against data reuse were not found to be major impediments for reuse contrary to our expectations. We found that reported use of models and remotely-sensed data was associated with greater reuse. The results suggest that data reuse would be encouraged and normalized by demonstration of its value. We offer some theoretical and practical suggestions that could help to legitimize investment and policies in favor of data sharing.

  18. Attitudes and norms affecting scientists’ data reuse

    Science.gov (United States)

    Curty, Renata Gonçalves; Specht, Alison; Grant, Bruce W.; Dalton, Elizabeth D.

    2017-01-01

    The value of sharing scientific research data is widely appreciated, but factors that hinder or prompt the reuse of data remain poorly understood. Using the Theory of Reasoned Action, we test the relationship between the beliefs and attitudes of scientists towards data reuse, and their self-reported data reuse behaviour. To do so, we used existing responses to selected questions from a worldwide survey of scientists developed and administered by the DataONE Usability and Assessment Working Group (thus practicing data reuse ourselves). Results show that the perceived efficacy and efficiency of data reuse are strong predictors of reuse behaviour, and that the perceived importance of data reuse corresponds to greater reuse. Expressed lack of trust in existing data and perceived norms against data reuse were not found to be major impediments for reuse contrary to our expectations. We found that reported use of models and remotely-sensed data was associated with greater reuse. The results suggest that data reuse would be encouraged and normalized by demonstration of its value. We offer some theoretical and practical suggestions that could help to legitimize investment and policies in favor of data sharing. PMID:29281658

  19. Attitudes and norms affecting scientists' data reuse.

    Directory of Open Access Journals (Sweden)

    Renata Gonçalves Curty

    Full Text Available The value of sharing scientific research data is widely appreciated, but factors that hinder or prompt the reuse of data remain poorly understood. Using the Theory of Reasoned Action, we test the relationship between the beliefs and attitudes of scientists towards data reuse, and their self-reported data reuse behaviour. To do so, we used existing responses to selected questions from a worldwide survey of scientists developed and administered by the DataONE Usability and Assessment Working Group (thus practicing data reuse ourselves. Results show that the perceived efficacy and efficiency of data reuse are strong predictors of reuse behaviour, and that the perceived importance of data reuse corresponds to greater reuse. Expressed lack of trust in existing data and perceived norms against data reuse were not found to be major impediments for reuse contrary to our expectations. We found that reported use of models and remotely-sensed data was associated with greater reuse. The results suggest that data reuse would be encouraged and normalized by demonstration of its value. We offer some theoretical and practical suggestions that could help to legitimize investment and policies in favor of data sharing.

  20. Review of the technological approaches for grey water treatment and reuses.

    Science.gov (United States)

    Li, Fangyue; Wichmann, Knut; Otterpohl, Ralf

    2009-05-15

    Based on literature review, a non-potable urban grey water reuse standard is proposed and the treatment alternatives and reuse scheme for grey water reuses are evaluated according to grey water characteristics and the proposed standard. The literature review shows that all types of grey water have good biodegradability. The bathroom and the laundry grey water are deficient in both nitrogen and phosphors. The kitchen grey water has a balanced COD: N: P ratio. The review also reveals that physical processes alone are not sufficient to guarantee an adequate reduction of the organics, nutrients and surfactants. The chemical processes can efficiently remove the suspended solids, organic materials and surfactants in the low strength grey water. The combination of aerobic biological process with physical filtration and disinfection is considered to be the most economical and feasible solution for grey water recycling. The MBR appears to be a very attractive solution in collective urban residential buildings.

  1. Record Management and Design Reuse

    Science.gov (United States)

    Briggs, Hugh C.

    2008-01-01

    Government mandated records management requirements apply to retention and long term archival of a wide variety of records. Part of the attention is on permanent accession and retention by the U.S. National Archives and Records Administration (NARA) but interim requirements for storage by the source agency are included. As government agencies and the Department of Defense move toward implementations, additional goals often include saving design data for reuse. This paper briefly reviews the government records management requirements then investigates candidate meanings of 'reuse' and proposes an enhanced design records retention approach. The recommended strategy that emerges is, for a given program or product family, to invest in rich and readily re-executable preservation of design artifacts for one or two subsequent generations, then downgrade the data in utility through conversions, ultimately reaching the NARA minimum standard for permanent historical-interest archives.

  2. Sodium Hydroxide and Calcium Hydroxide Hybrid Oxygen Bleaching with System

    Science.gov (United States)

    Doelle, K.; Bajrami, B.

    2018-01-01

    This study investigates the replacement of sodium hydroxide in the oxygen bleaching stage using a hybrid system consisting of sodium hydroxide calcium hydroxide. Commercial Kraft pulping was studied using yellow pine Kraft pulp obtained from a company in the US. The impact of sodium hydroxide, calcium hydroxide hybrid system in regard to concentration, reaction time and temperature for Kraft pulp was evaluated. The sodium hydroxide and calcium hydroxide dosage was varied between 0% and 15% based on oven dry fiber content. The bleaching reaction time was varied between 0 and 180 minutes whereas the bleaching temperature ranged between 70 °C and 110 °C. The ability to bleach pulp was measured by determining the Kappa number. Optimum bleaching results for the hybrid system were achieved with 4% sodium hydroxide and 2% calcium hydroxide content. Beyond this, the ability to bleach pulp decreased.

  3. Levels of enamel erosion for the application of bleaching agents

    OpenAIRE

    Díaz Soriano, Ana; Departamento Académico de Estomatología Biosocial.; Pérez Vargas, Luis; Departamento Academico de Estomatología Biosocial.; Mattos Vela, Manuel; Departamento Academico de Estomatología Biosocial.; Asurza Ruiz, José; Instituto Nacional de Enfermedades Neoplásicas - INEN.; Bernuy Torres, Luis

    2014-01-01

    Dental bleaching systems and its use of toothpaste with bleaching agents lead to search the effect of these systems on the enamel surface. Scientific evidence shows that these systems can provoke an answer in chemical shucture of the dental enamel with loss of calcium . The concentration of calcium was measured in ppm in 27 crowns of human bicuspids. The enamel erosion was measured through the liberation of calcium salts into teeth in two kinds of bleaching toothpastes : Crest whitening and C...

  4. Coral mass bleaching and reef temperatures at Navassa Island, 2006

    Science.gov (United States)

    Miller, M. W.; Piniak, G. A.; Williams, D. E.

    2011-01-01

    Bleaching and associated mortality is an extreme threat to the persistence of coral populations in the projected warming regime of the next few decades. Recent evidence indicates that thermal bleaching thresholds may be affected by water quality gradients. The unexpected encounter of a coral mass bleaching event at a remote, uninhabited Caribbean island (Navassa) during a routine reef assessment cruise in November 2006 provided the opportunity to characterize bleaching responses and thermal exposure in an oceanic area with negligible continental influence or human impact on water quality. The coral taxa most susceptible to bleaching were Agaricia spp. and Montastraea faveolata. Siderastraea siderea, Diploria spp. and Porites porites were intermediately affected, while Porites astreoides and Montastraea cavernosa were minimally affected and negligible bleaching was observed in Acropora palmata. Bleaching prevalence (colonies > 4 cm diameter) ranged from 0.16 to 0.63 among sites. Deeper sites (between 18 and 37 m) had significantly higher prevalence of bleaching than shallow sites (<10 m). This general pattern of more bleaching in deeper sites also occurred within species. Though exposure to high-temperature stress was not greater at deeper sites, water motion, which may bolster bleaching resistance, was likely less. In situ loggers indicated temperatures over 30 °C initiated at shallow sites in mid-August, at deeper sites in early September, and were persistent at all sites until mid-October. Long term (1983-2007) climatologies constructed from AVHRR SSTs suggest that the mass bleaching event observed at Navassa in 2006 corresponded with greater intensity and duration of warm temperature anomalies than occurred in 2005, for which no in situ observations (bleaching nor temperature) are available.

  5. Effects of a New Bleaching Gel on Tooth Whitening

    Science.gov (United States)

    2016-05-17

    include ease of application, reduced chair time and cost, high success rate, and safety of materials.6 Furthermore, bleaching teeth with 10... dental workhorse for over 70 years.4 HP’s bleaching success is attributed to its ability to penetrate tooth structure and produce free radicals that...home whitening. Due to the prevalence of HP and CP in many bleaching products, the dental literature is saturated with research on their respective

  6. Identifying well-bleached quartz using the different bleaching rates of quartz and feldspar luminescence signals

    DEFF Research Database (Denmark)

    Murray, A.S.; Thomsen, Kristina Jørkov; Masuda, N.

    2012-01-01

    the likely significance of the difficult-to-bleach residual feldspar signals in non-aeolian samples. For a set of mainly Late Pleistocene non-aeolian sediments, large aliquot quartz doses are then used to predict feldspar doses (based on a knowledge of the sample dose rates). The differences between observed...... that the large aliquot data are more likely to be correct. We conclude that a comparison of quartz and feldspar doses provides a useful independent method for identifying well-bleached quartz samples, and that it is unwise to apply statistical models to dose distributions without clear evidence for the physical...

  7. Formalisms for reuse and systems integration

    CERN Document Server

    Rubin, Stuart

    2015-01-01

    Reuse and integration are defined as synergistic concepts, where reuse addresses how to minimize redundancy in the creation of components; while, integration focuses on component composition. Integration supports reuse and vice versa. These related concepts support the design of software and systems for maximizing performance while minimizing cost. Knowledge, like data, is subject to reuse; and, each can be interpreted as the other. This means that inherent complexity, a measure of the potential utility of a system, is directly proportional to the extent to which it maximizes reuse and integration. Formal methods can provide an appropriate context for the rigorous handling of these synergistic concepts. Furthermore, formal languages allow for non ambiguous model specification; and, formal verification techniques provide support for insuring the validity of reuse and integration mechanisms.   This edited book includes 12 high quality research papers written by experts in formal aspects of reuse and integratio...

  8. Problems of multiphase fluid filtration

    CERN Document Server

    Konovalov, AN

    1994-01-01

    This book deals with a spectrum of problems related to the mathematical modeling of multiphase filtration. Emphasis is placed on an inseparable triad: model - algorithm - computer code. An analysis of new and traditional filtration problems from the point of view of both their numerical implementation and the reproduction of one or another technological characteristics of the processes under consideration is given. The basic principles which underlie the construction of efficient numerical methods taking into account the filtration problems are discussed: non-evolutionary nature, degeneration,

  9. Therapeutic effectiveness of a new enzymatic bleaching dentifrice.

    Science.gov (United States)

    Forner, Leopaldo; Amengual, José; Liena, Carmen; Riutord, Pere

    2012-01-01

    Research into bleaching focuses on new products in order to minimize undesirable effects. This study evaluated the bleaching effectiveness of a new enzymatic-activated dentifrice. A total of 20 volunteers were bleached with a dentifrice containing 5% lactoperoxidase and 3% carbamide peroxide applied three times a day for two minutes over 21 days. Color was recorded before and after the treatment using a spectrophotometer. CIELAB differences were calculated before and after treatment using the paired t test (P whitening teeth. Enzymatic dental bleaching is able to increase the efficiency of low concentration peroxides, reducing the potential risk of peroxides on oral tissues.

  10. Coral community response to bleaching on a highly disturbed reef.

    Science.gov (United States)

    Guest, J R; Low, J; Tun, K; Wilson, B; Ng, C; Raingeard, D; Ulstrup, K E; Tanzil, J T I; Todd, P A; Toh, T C; McDougald, D; Chou, L M; Steinberg, P D

    2016-02-15

    While many studies of coral bleaching report on broad, regional scale responses, fewer examine variation in susceptibility among coral taxa and changes in community structure, before, during and after bleaching on individual reefs. Here we report in detail on the response to bleaching by a coral community on a highly disturbed reef site south of mainland Singapore before, during and after a major thermal anomaly in 2010. To estimate the capacity for resistance to thermal stress, we report on: a) overall bleaching severity during and after the event, b) differences in bleaching susceptibility among taxa during the event, and c) changes in coral community structure one year before and after bleaching. Approximately two thirds of colonies bleached, however, post-bleaching recovery was quite rapid and, importantly, coral taxa that are usually highly susceptible were relatively unaffected. Although total coral cover declined, there was no significant change in coral taxonomic community structure before and after bleaching. Several factors may have contributed to the overall high resistance of corals at this site including Symbiodinium affiliation, turbidity and heterotrophy. Our results suggest that, despite experiencing chronic anthropogenic disturbances, turbid shallow reef communities may be remarkably resilient to acute thermal stress.

  11. Arundo donax L. reed: new perspectives for pulping and bleaching. Part 4. Peroxide bleaching of organosolv pulps.

    Science.gov (United States)

    Shatalov, A A; Pereira, H

    2005-05-01

    A comparative study on TCF (totally chlorine-free) bleachability of organosolv pulps from the annual fibre crop Arundo donax L. (giant reed) was carried out using a simple three-stage peroxide bleaching sequence without oxygen pre-bleaching. ASAM (alkali-sulfite-anthraquinone-methanol), Organocell (alkali-anthraquinone-methanol) and ethanol-soda organosolv pulps were bleached and compared with kraft pulp, as a reference. The final brightness of 76-78% ISO was attained for all tested pulps. The chemical charge required to reach this level of brightness varied for different pulps (despite the equal initial content of the residual lignin) and directly related to starting brightness values. No direct correlation between brightness improvement and lignin removal during bleaching was found, indicating the influence of the specific pulp properties introduced by pulping process on bleaching chemistry. The general higher bleaching response of organosolv pulps from A. donax was noted in comparison with kraft.

  12. Latest aspects of mechanical filtration

    Directory of Open Access Journals (Sweden)

    Stanislav Koláček

    2013-01-01

    Full Text Available The aim of this study was to describe and unify all knowledge about mechanic filtration. The first part deals with the parameters and properties of filtration. Here some important basic concepts are explained such as pressure gradient, filter life, etc. There’s also a description of convenient filtration technology for coarse and fine materials, such as sand, smoke or soot. The second part primarily focuses on the real use and application of filters for liquid and gaseous media. The differences in construction between different types of filters for filtration of fuels, oils, hydraulic fluids, air and cabin filters are described. The last section is focused mainly on new materials for the production of filters. These materials are ceramic or nanomaterials, which can actually be enriched for example with antibacterial silver or some fungicides.

  13. The influence of bleaching agent and temperature on bleaching efficacy and volatile components of fluid whey and whey retentate.

    Science.gov (United States)

    Fox, A J; Smith, T J; Gerard, P D; Drake, M A

    2013-10-01

    Fluid whey or retentate are often bleached to remove residual annatto Cheddar cheese colorant, and this process causes off-flavors in dried whey proteins. This study determined the impact of temperature and bleaching agent on bleaching efficacy and volatile components in fluid whey and fluid whey retentate. Freshly manufactured liquid whey (6.7% solids) or concentrated whey protein (retentate) (12% solids, 80% protein) were bleached using benzoyl peroxide (BP) at 100 mg/kg (w/w) or hydrogen peroxide (HP) at 250 mg/kg (w/w) at 5 °C for 16 h or 50 °CC for 1 h. Unbleached controls were subjected to a similar temperature profile. The experiment was replicated three times. Annatto destruction (bleaching efficacy) among treatments was compared, and volatile compounds were extracted and separated using solid phase microextraction gas chromatography mass spectrometry (SPME GC-MS). Bleaching efficacy of BP was higher than HP (P 0.05). Retentate bleached with HP at either temperature had higher relative abundances of pentanal, hexanal, heptanal, and octanal than BP bleached retentate (P < 0.05). Liquid wheys generally had lower concentrations of selected volatiles compared to retentates. These results suggest that the highest bleaching efficacy (within the parameters evaluated) in liquid whey is achieved using BP at 5 or 50 °C and at 50 °C with HP or BP in whey protein retentate. © 2013 Institute of Food Technologists®

  14. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also, reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percent age improvement in health outcomes is typically modest, for example, 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  15. Health Benefits of Particle Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.

    2013-10-01

    The evidence of health benefits of particle filtration in homes and commercial buildings is reviewed. Prior reviews of papers published before 2000 are summarized. The results of 16 more recent intervention studies are compiled and analyzed. Also reviewed are four studies that modeled health benefits of using filtration to reduce indoor exposures to particles from outdoors. Prior reviews generally concluded that particle filtration is, at best, a source of small improvements in allergy and asthma health effects; however, many early studies had weak designs. A majority of recent intervention studies employed strong designs and more of these studies report statistically significant improvements in health symptoms or objective health outcomes, particularly for subjects with allergies or asthma. The percentage improvement in health outcomes is typically modest, e.g., 7percent to 25percent. Delivery of filtered air to the breathing zone of sleeping allergic or asthmatic persons may be more consistently effective in improving health than room air filtration. Notable are two studies that report statistically significant improvements, with filtration, in markers that predict future adverse coronary events. From modeling, the largest potential benefits of indoor particle filtration may be reductions in morbidity and mortality from reducing indoor exposures to particles from outdoor air.

  16. Comparison of laser and power bleaching techniques in tooth color change

    OpenAIRE

    Fekrazad, Reza; Alimazandarani, Shervin; Kalhori, Katayoun A.M.; Assadian, Hadi; Mirmohammadi, Seyed-Mahdi

    2017-01-01

    Background Laser-assisted bleaching uses laser beam to accelerate release of free radicals within the bleaching gel to decrease time of whitening procedure. The aim of this study was to compare the efficacy of power bleaching using Opalescence Xtra Boost? and laser bleaching technique using LaserSmile gel and diode laser as an activator in their tooth whitening capacity. Material and Methods Student t test showed that the laser bleaching group significantly outperformed the power bleaching gr...

  17. Greywater characterization and loadings - Physicochemical treatment to promote onsite reuse.

    Science.gov (United States)

    Noutsopoulos, C; Andreadakis, A; Kouris, N; Charchousi, D; Mendrinou, P; Galani, A; Mantziaras, I; Koumaki, E

    2017-06-04

    Greywater is the wastewater produced in bathtubs, showers, hand basins, kitchen sinks, dishwashers and laundry machines. Segregation of greywater and blackwater and on site greywater treatment in order to promote its reuse for toilet flushing and/or garden irrigation is an interesting option especially in water deficient areas. The objective of this study was to characterize the different greywater sources in Greek households and to evaluate the performance of alternative physicochemical treatment systems to treat several types of greywater. Based on the results average daily greywater production was equal to 98 L per person per day and accounts for approximately 70-75% of the total household wastewater production (135 L per person per day). Among the different sources, laundry and kitchen sink are the main contributors to the total greywater load of organic carbon, suspended solids and surfactants, whereas dishwasher and bathroom greywater are the main sources of phosphorus and endocrine disrupting chemicals respectively. Depending on sources, greywater accounts for as low as 15% of the total wastewater load of organic carbon (in the case of light greywater sources), to as high as 74% of the total load organic load (in the case of the heavy greywater sources). On the other hand, the nutrients load of greywater is limited. The application of a physical treatment system consisting of coagulation, sedimentation, sand filtration, granular activated carbon filtration and disinfection can provide for a final effluent with high quality characteristics for onsite reuse, especially when treating light greywater. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. ICT reuse in socio-economic enterprises

    International Nuclear Information System (INIS)

    Ongondo, F.O.; Williams, I.D.; Dietrich, J.; Carroll, C.

    2013-01-01

    Highlights: • We analyse ICT equipment reuse operations of socio-economic enterprises. • Most common ICT products dealt with are computers and related equipment. • In the UK in 2010, ∼143,750 appliances were reused. • Marketing and legislative difficulties are the common hurdles to reuse activities. • Socio-economic enterprises can significantly contribute to resource efficiency. - Abstract: In Europe, socio-economic enterprises such as charities, voluntary organisations and not-for-profit companies are involved in the repair, refurbishment and reuse of various products. This paper characterises and analyses the operations of socio-economic enterprises that are involved in the reuse of Information and Communication Technology (ICT) equipment. Using findings from a survey, the paper specifically analyses the reuse activities of socio-economic enterprises in the UK from which Europe-wide conclusions are drawn. The amount of ICT products handled by the reuse organisations is quantified and potential barriers and opportunities to their operations are analysed. By-products from reuse activities are discussed and recommendations to improve reuse activities are provided. The most common ICT products dealt with by socio-economic enterprises are computers and related equipment. In the UK in 2010, an estimated 143,750 appliances were reused. However, due to limitations in data, it is difficult to compare this number to the amount of new appliances that entered the UK market or the amount of waste electrical and electronic equipment generated in the same period. Difficulties in marketing products and numerous legislative requirements are the most common barriers to reuse operations. Despite various constraints, it is clear that organisations involved in reuse of ICT could contribute significantly to resource efficiency and a circular economy. It is suggested that clustering of their operations into “reuse parks” would enhance both their profile and their

  19. ICT reuse in socio-economic enterprises

    Energy Technology Data Exchange (ETDEWEB)

    Ongondo, F.O., E-mail: f.ongondo@soton.ac.uk [Centre for Environmental Sciences, Faculty of Engineering and the Environment, Lanchester Building, University of Southampton, University Rd., Highfield, Southampton, Hampshire SO17 1BJ (United Kingdom); Williams, I.D. [Centre for Environmental Sciences, Faculty of Engineering and the Environment, Lanchester Building, University of Southampton, University Rd., Highfield, Southampton, Hampshire SO17 1BJ (United Kingdom); Dietrich, J. [Technische Universität Berlin, Centre for Scientific Continuing Education and Cooperation, Cooperation and Consulting for Environmental Questions (kubus) FH10-1, Fraunhoferstraße 33-36, 10587 Berlin (Germany); Carroll, C. [Centre for Environmental Sciences, Faculty of Engineering and the Environment, Lanchester Building, University of Southampton, University Rd., Highfield, Southampton, Hampshire SO17 1BJ (United Kingdom)

    2013-12-15

    Highlights: • We analyse ICT equipment reuse operations of socio-economic enterprises. • Most common ICT products dealt with are computers and related equipment. • In the UK in 2010, ∼143,750 appliances were reused. • Marketing and legislative difficulties are the common hurdles to reuse activities. • Socio-economic enterprises can significantly contribute to resource efficiency. - Abstract: In Europe, socio-economic enterprises such as charities, voluntary organisations and not-for-profit companies are involved in the repair, refurbishment and reuse of various products. This paper characterises and analyses the operations of socio-economic enterprises that are involved in the reuse of Information and Communication Technology (ICT) equipment. Using findings from a survey, the paper specifically analyses the reuse activities of socio-economic enterprises in the UK from which Europe-wide conclusions are drawn. The amount of ICT products handled by the reuse organisations is quantified and potential barriers and opportunities to their operations are analysed. By-products from reuse activities are discussed and recommendations to improve reuse activities are provided. The most common ICT products dealt with by socio-economic enterprises are computers and related equipment. In the UK in 2010, an estimated 143,750 appliances were reused. However, due to limitations in data, it is difficult to compare this number to the amount of new appliances that entered the UK market or the amount of waste electrical and electronic equipment generated in the same period. Difficulties in marketing products and numerous legislative requirements are the most common barriers to reuse operations. Despite various constraints, it is clear that organisations involved in reuse of ICT could contribute significantly to resource efficiency and a circular economy. It is suggested that clustering of their operations into “reuse parks” would enhance both their profile and their

  20. Reuse Metrics for Object Oriented Software

    Science.gov (United States)

    Bieman, James M.

    1998-01-01

    One way to increase the quality of software products and the productivity of software development is to reuse existing software components when building new software systems. In order to monitor improvements in reuse, the level of reuse must be measured. In this NASA supported project we (1) derived a suite of metrics which quantify reuse attributes for object oriented, object based, and procedural software, (2) designed prototype tools to take these measurements in Ada, C++, Java, and C software, (3) evaluated the reuse in available software, (4) analyzed the relationship between coupling, cohesion, inheritance, and reuse, (5) collected object oriented software systems for our empirical analyses, and (6) developed quantitative criteria and methods for restructuring software to improve reusability.

  1. Does deposition depth control the OSL bleaching of fluvial sediment?

    NARCIS (Netherlands)

    Cunningham, A. C.; Wallinga, J.; Hobo, N.; Versendaal, A. J.; Makaske, B.; Middelkoop, H.

    2014-01-01

    The Optically Stimulated Luminescence (OSL) signal from fluvial sediment often contains a remnant from the previous deposition cycle, leading to a partially bleached equivalent-dose distribution. Although identification of the burial dose is of primary concern, the degree of bleaching could

  2. Investigating Motivations for Women's Skin Bleaching in Tanzania

    Science.gov (United States)

    Lewis, Kelly M.; Robkin, Navit; Gaska, Karie; Njoki, Lillian Carol

    2011-01-01

    Why do many African women continue to use damaging skin-bleaching cosmetics that contain dangerous chemicals (e.g., mercury) that may increase their rates of infertility, skin cancer, and serious skin/brain/kidney disease? To address this question, our study investigated motivations driving the preservation of skin-bleaching practices in Tanzania.…

  3. The evaluation of hydrogen peroxide bleaching of Gonometa ...

    African Journals Online (AJOL)

    The effect of hydrogen peroxide bleaching on Gonometa postica silk and the influence that temperature, pH and time duration had on hydrogen peroxide release , colour change, breaking load and stiffness were determined. The best bleaching (81 delta E) of the Gonometa postica silk fabric was obtained with 60 minutes ...

  4. The bleaching syndrome: manifestation of a post-colonial pathology ...

    African Journals Online (AJOL)

    The post-colonial root of African problems is directly related to skin color. Under the cloak of personal preference, light skin among African women has replaced dark skin as the native ideal. The aftermath is manifestation of the Bleaching Syndrome. Social Work professionals have overlooked the Bleaching Syndrome as ...

  5. Anolyte as an alternative bleach for stained cotton fabrics ...

    African Journals Online (AJOL)

    ... as the two- and three-factor interactions. The results from the study indicated that Anolyte was less effective than sodium hypochlorite as a stain remover for blood, tea, soot/mineral oil and blackcurrant juice. It was noted that the temperature of bleach liquids had an influence on the removal of stains by both bleach liquids.

  6. Color Recovery Effect of Different Bleaching Systems on a ...

    African Journals Online (AJOL)

    Background and Purpose: Discoloration of resin‑based composites is a commonly encountered problem, and bleaching agents may be used for the therapy of the existing discoloration. The purpose of this study was to investigate in vitro color recovery effect of different bleaching systems on the heavily discolored composite ...

  7. FT–Raman investigation of bleaching of spruce thermomechanical pulp

    Science.gov (United States)

    U.P. Agarwal; L.L. Landucci

    2004-01-01

    Spruce thermomechanical pulp was bleached initially by alkaline hydrogen peroxide and then by sodium dithionite and sodium borohydride. Near-infrared Fourier-transform–Raman spectroscopy revealed that spectral differences were due primarily to coniferaldehyde and p-quinone structures in lignin, new direct evidence that bleaching removes p-quinone structures. In...

  8. The Bleaching Syndrome: Manifestation of a Post-Colonial ...

    African Journals Online (AJOL)

    The post-colonial root of African problems is directly related to skin color. Under the cloak of personal preference, light skin among African women has replaced dark skin as the native ideal. The aftermath is manifestation of the Bleaching Syndrome. Guidance and Counselling professionals have overlooked the Bleaching ...

  9. Symbiont Dependent Thermal Bleaching Susceptiblity in Two Reef ...

    African Journals Online (AJOL)

    Symbiont Dependent Thermal Bleaching Susceptiblity in Two Reef-building Corals, Stylophora pistillata and Platygyra ryukyuensis . ... Symbiodinium ITS2 types exhibit diverse photo-physiological responses to thermal stress, and may partially explain the variable bleaching susceptibilities of some hermatypic coral species.

  10. Alkali and bleach treatment of the extracted cellulose from pineapple ...

    African Journals Online (AJOL)

    We successfully extracted cellulose from pineapple leaves (Ananas comosus) using alkali treatment and bleaching. Alkali treatment was done using aqueous sodium hydroxide while bleaching was done using acetate buffer and aqueous sodium chlorite. The extracted cellulose was characterized using Scanning electron ...

  11. Color Recovery Effect of Different Bleaching Systems on a ...

    African Journals Online (AJOL)

    2018-02-07

    Feb 7, 2018 ... Odontology 2016;104:305-9. 29. Joiner A. The bleaching of teeth: A review of the literature. J Dent 2006;34:412-9. 30. Haywood VB, Heymann HO. Nightguard vital bleaching: How safe is it? Quintessence Int 1991;22:515-23. 31. Fay RM, Servos T, Powers JM. Color of restorative materials after staining and ...

  12. Direct potable reuse – a feasible water management option

    Directory of Open Access Journals (Sweden)

    J. Lahnsteiner

    2018-03-01

    Full Text Available Direct potable reuse (DPR can be more economic than indirect potable reuse as no environmental buffer is needed and conveyance and blending of the purified water with other potable sources is basically less expensive. Long-term experience in Windhoek (48 years shows that treated domestic sewage can be safely and cost-efficiently utilized for potable reclamation (0.72 €/m3. A multiple barrier strategy is employed in order to attain the highest possible safety levels. There are three types of barriers: non-treatment, treatment and operational barriers. In recent years, new DPR schemes have been implemented in South Africa and in the USA, and the major difference between all the new reclamation processes and the Windhoek New Goreangab water reclamation plant lies in the employment of desalination process units. This topic and other issues, such as the use of ozone and biological activated carbon filtration, are addressed. Reclamation process optimization (increase in sustainability and the attainment of greater public acceptance are the major challenges facing the promotion of DPR, which should become a common and widely used water management option within the next 5–10 years.

  13. Effects of bleaching agents on surface roughness of filling materials.

    Science.gov (United States)

    Markovic, Ljubisa; Jordan, Rainer Andreas; Glasser, Marie-Claire; Arnold, Wolfgang Hermann; Nebel, Jan; Tillmann, Wolfgang; Ostermann, Thomas; Zimmer, Stefan

    2014-01-01

    The aim of this study was to use a non-tactile optical measurement system to assess the effects of three bleaching agents' concentrations on the surface roughness of dental restoration materials. Two composites (Grandio, Venus) and one glass ionomer cement (Ketac Fil Plus) were used in this in vitro study. Specimens were treated with three different bleaching agents (16% and 22% carbamide peroxide (Polanight) and 38% hydrogen peroxide (Opalescence Boost)). Surface roughness was measured with an optical profilometer (Infinite Focus G3) before and after the bleaching treatment. Surface roughness increased in all tested specimens after bleaching treatment (p<0.05). Our in vitro study showed that dental bleaching agents influenced the surface roughness of different restoration materials, and the restoration material itself was shown to have an impact on alteration susceptibility. There seemed to be no clinical relevance in case of an optimal finish.

  14. Dental pulp vascular permeability changes induced by dental bleaching

    Directory of Open Access Journals (Sweden)

    Cristiane da Costa

    2012-02-01

    Full Text Available Aiming to compare the effect of different light sources for dental bleaching on vascular permeability of dental pulps, forty-eight incisors were used. The bleaching agent (35 % hydrogen peroxide was activated by halogen light; LED (Light Emitting Diode or LED, followed by laser phototherapy (LPT (λ = 780 nm; 3 J/cm². After the bleaching procedures, the animals received an intra-arterial dye injection and one hour later were sacrificed. The teeth were diaphanized and photographed. The amount of blue stain content of each dental pulp was quantified using a computer imaging program. The data was statistically compared (p < 0.05. The results showed a significant higher (p < 0.01 dye content in the groups bleached with halogen light, compared with the control, LED and LED plus LPT groups. Thus, tooth bleaching activated by LED or LED plus LPT induces lesser resulted in increased vascular permeability than halogen light.

  15. Coral bleaching pathways under the control of regional temperature variability

    Science.gov (United States)

    Langlais, C. E.; Lenton, A.; Heron, S. F.; Evenhuis, C.; Sen Gupta, A.; Brown, J. N.; Kuchinke, M.

    2017-11-01

    Increasing sea surface temperatures (SSTs) are predicted to adversely impact coral populations worldwide through increasing thermal bleaching events. Future bleaching is unlikely to be spatially uniform. Therefore, understanding what determines regional differences will be critical for adaptation management. Here, using a cumulative heat stress metric, we show that characteristics of regional SST determine the future bleaching risk patterns. Incorporating observed information on SST variability, in assessing future bleaching risk, provides novel options for management strategies. As a consequence, the known biases in climate model variability and the uncertainties in regional warming rate across climate models are less detrimental than previously thought. We also show that the thresholds used to indicate reef viability can strongly influence a decision on what constitutes a potential refugia. Observing and understanding the drivers of regional variability, and the viability limits of coral reefs, is therefore critical for making meaningful projections of coral bleaching risk.

  16. Reuse of hydroponic waste solution.

    Science.gov (United States)

    Kumar, Ramasamy Rajesh; Cho, Jae Young

    2014-01-01

    Attaining sustainable agriculture is a key goal in many parts of the world. The increased environmental awareness and the ongoing attempts to execute agricultural practices that are economically feasible and environmentally safe promote the use of hydroponic cultivation. Hydroponics is a technology for growing plants in nutrient solutions with or without the use of artificial medium to provide mechanical support. Major problems for hydroponic cultivation are higher operational cost and the causing of pollution due to discharge of waste nutrient solution. The nutrient effluent released into the environment can have negative impacts on the surrounding ecosystems as well as the potential to contaminate the groundwater utilized by humans for drinking purposes. The reuse of non-recycled, nutrient-rich hydroponic waste solution for growing plants in greenhouses is the possible way to control environmental pollution. Many researchers have successfully grown several plant species in hydroponic waste solution with high yield. Hence, this review addresses the problems associated with the release of hydroponic waste solution into the environment and possible reuse of hydroponic waste solution as an alternative resource for agriculture development and to control environmental pollution.

  17. Bleaching of reef coelenterates in the San Blas Islands, Panama

    Science.gov (United States)

    Lasker, Howard R.; Peters, Esther C.; Coffroth, Mary Alice

    1984-12-01

    Starting in June 1983, 25 species of hermatypic corals, gorgonians, hydrocorals, anemones and zoanthids in the San Blas Islands, Panama, began showing signs of a loss of colour leading in some cases to a white “bleached” appearance. Histologic examination of six coral species indicated that bleaching was associated with drastic reductions in the density of zooxanthellae and with the atrophy and necrosis of the animal tissue. The severity of the bleaching varied among species and many species were unaffected. The species most extensively affected were: Agaricia spp., which became completely bleached and frequently died; Montastraea annularis which bleached and continued to survive; and Millepora spp. which bleached white but quickly regained their colouration. Shallow reefs dominated by Agaricia spp. suffered the most extensive bleaching. At one site, Pico Feo, 99% of the Agaricia (32% of the living cover) was bleached. On fore reers, which were dominated by Agaricia spp. and M. annularis, the proportion of M. annularis bleached ranged from 18 to 100% and that of Agaricia spp. from 30 to 53%. Transects at Sail Rock and House Reef were surveyed in August 1983 and January 1984. At those sites, 53% of the Agaricia cover died between August and January. The remaining living cover of Agaricia and of all other species exhibited normal colouration in January. Salinity and temperature were monitored every second day at 4 m depth between May 10 and August 28, 1983 at one of the localities. Bleaching was first observed within two weeks of a 2 °C rise in temperature which occurred in late May 1983. Temperatures remained at or above 31.5 °C for the following 3 weeks and were at or above 30 °C for an additional 4 weeks. The bleaching of corals in the San Blas was most likely due to those elevanted temperatures.

  18. Single-use device reuse risks.

    Science.gov (United States)

    Lee, Robert C; Berzins, Sandy; Alfieri, Nancy

    2007-01-01

    Efforts to reduce both costs and medical waste have led many health systems to start reusing single-use medical devices (SUDs) after cleaning and sterilizing (i.e. reprocessing). There is a currently a wide range of SUD types being reused in many health systems. The objective of this paper is to provide a brief summary of risk issues associated with critical SUDs, based on a rapid review of the available literature. The specific focus is on risk issues, but includes discussion of economic and legal/ethical issues as well. The evidence in the literature regarding the safety of reuse of SUDs indicates that for certain devices (e.g. heart catheters) reuse can be safe (in terms of patient infection) and cost-effective as long as stringent reprocessing protocols are followed. However, potential risks associated with reusing SUDs are not just limited to infection of patients. There are staff and environmental risks, plus important legal, ethical, and financial issues to consider in a reuse policy. There are currently no Canadian guidelines on reuse or reprocessing SUDs, although a national Scientific Advisory Panel on Reprocessing of Medical Devices has made recommendations. Additionally, reuse of SUDs is interwoven with the issue of infection control and reprocessing procedures in general and as applied to multiple-use devices. With limited healthcare resources, there will always be a trade-off between the human resources and costs required to clean and sterilize reused devices with costs associated with purchasing and disposing of non-reused SUDs. Evaluation of complete operational pathways, especially for more expensive and commonly used SUDs, will be useful to properly determine the balance of benefits, risks, and costs under a reuse policy.

  19. Integrated pore blockage-cake filtration model for crossflow filtration

    International Nuclear Information System (INIS)

    Daniel, Richard C.; Billing, Justin M.; Russell, Renee L.; Shimskey, Rick W.; Smith, Harry D.; Peterson, Reid A.

    2011-01-01

    Crossflow filtration is to be a key process in the treatment and disposal of approximately 60,000 metric tons of high-level radioactive waste stored at the Hanford Site in Richland, Washington. Pacific Northwest National Laboratory is assessing filter performance with waste simulant materials that mimic the chemical and physical properties of Hanford tank waste. Prior simulant studies indicated that waste filtration performance may be limited by pore and cake fouling. To limit the shutdown of waste treatment operations, the pre-treatment facility plans to recover filter flux losses from cake formation and filter fouling by frequently backpulsing the filter elements. The objective of the current paper is to develop a simple model of flux decline resulting from cake and pore fouling and potential flux recovery through backpulsing of the filters for Hanford waste filtration operations. To this end, a model capable of characterizing the decline in waste-simulant filter flux as a function of both irreversible pore blockage and reversible cake formation is proposed. This model is used to characterize the filtration behavior of Hanford waste simulants in both continuous and backpulsed operations. The model is then used to infer the optimal backpulse frequency under specific operating conditions.

  20. Nova tecnologia de branqueamento de celulose adaptada ao fechamento do circuito de água A novel bleaching technology adapted to partial bleach plant closure

    Directory of Open Access Journals (Sweden)

    Marcelo Moreira Costa

    2006-02-01

    (EOPD(EPD and D(EOPDP, respectively. The mill has an activated sludge effluent treatment plant comprised of two aeration tanks with 20,000 m3 and it is equipped with superficial aerators followed by four secondary clarifiers (two for each reactor. In the last decades, CENIBRA has been optimizing and changing its processes in order to improve environmental performance. Aiming at decreasing effluent volume, COD and AOX loads, the Ahot(EOPD(PO sequence has been proposed and evaluated in lab-scale trials, with partial filtrate recycling. This paper proposes a filtrate recycling scheme that reduces bleach plant effluent volume by 9 m3/adt (air dry ton, i.e., about 50% of the total. The filtrate saved is partially diverted to the recausticizing cycle and to post oxygen washers. The reutilization of the Ahot filtrate in the recausticizing cycle to replace the filtrates currently used to wash lime mud and dregs was shown suitable. The impact of NPE´s in the calcium cycle was not significant. This strategy allowed a recovery of c.a. 12 kg NaOH/adt of pulp that would otherwise be wasted. Pulp bleachability and quality was not significantly affected. The discharged effluent coming from D(PO stages (about 50% showed low color, COD and AOX loads, and good bio-treatability (DBO5/COD.

  1. Filtration and compression of organic materials

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Keiding, Kristian

    is to use more simple systems. Dextran-MnO2 particles and polystyrene particles with a water-swollen polyacrylic acid shell have therefore been synthesised. These particles have been filtered and used to study the non-linear filtration behaviour. The compressibility of the formed cake has been investigated......The conventional filtration theory has been based on filtrations of incompressible particles such as anatase, kaolin and clay. The filtration models have later been used for organic slurries but can often not explain the observed experimental data. At constant pressure, the filtrate volume does...... and the discrepancy between the filtration theory and the observed filtration behaviour explained as a time-dependent collapse of the formed cake (creep). Thus, the creep phenomenon has been adopted in the conventional filtration models and it will be shown that the model can be used to simulate filtration data...

  2. Environmental benefits from reusing clothes

    DEFF Research Database (Denmark)

    Farrant, Laura; Olsen, Stig Irving; Wangel, Arne

    2010-01-01

    on the identification of the different profiles of the consumers questioned, a methodology was developed to get a quantitative evaluation of the replacement of new clothes enabled by second-hand clothing consumption. A Life cycle Assessment was conducted based on the EDIP methodology. The life cycle impacts of clothes...... clothes actually results in a decrease of the environmental burden of the life cycle of clothing. The environmental burden of clothing has been studied in several studies. However, most of these studies focus solely on the energy consumption aspects and pay little attention to the potential benefits...... that are directly disposed of by incineration were compared with the life cycle impacts of clothes that are collected and sorted after consumer use in order to be reused. Two products were assessed: a cotton T-shirt and a pair of polyester (65%)/cotton (35%) trousers. The functional unit was 100 garments in the use...

  3. the greywater reuse case of Jordan

    International Development Research Centre (IDRC) Digital Library (Canada)

    Fox Run Craftsmen

    2003-03-06

    Mar 6, 2003 ... in Jordan, Palestine, Lebanon, and Designed to Expand to Syria. ❖ Ratified Hyderabad .... intensive production methods and re-using natural resources and urban wastes. Massive urbanization ...... outline the concrete results of the CFP greywater reuse project in Jordan, and noted that wastewater results ...

  4. Understanding farmers' preferences for wastewater reuse ...

    African Journals Online (AJOL)

    South Africa has included water reuse as a policy option; hence the aim of this study is to understand farmers' preferences regarding water reuse frameworks for irrigation. A choice modelling approach was applied to identify the elements defining these frameworks and to quantify their relative importance amongst farmers in ...

  5. Invited review: Annatto usage and bleaching in dairy foods.

    Science.gov (United States)

    Kang, E J; Campbell, R E; Bastian, E; Drake, M A

    2010-09-01

    Annatto is a yellow/orange colorant that is widely used in the food industry, particularly in the dairy industry. Annatto, consisting of the carotenoids bixin and norbixin, is most commonly added to produce orange cheese, such as Cheddar, to achieve a consistent color over seasonal changes. This colorant is not all retained in the cheese, and thus a percentage remains in the whey, which is highly undesirable. As a result, whey is often bleached. Hydrogen peroxide and benzoyl peroxide are the 2 bleaching agents currently approved for bleaching whey in the United States. Recent studies have highlighted the negative effect of bleaching on whey flavor while concurrently there is a dearth of current studies on bleaching conditions and efficacy. Recent international mandates have placed additional concern on the use of benzoyl peroxide as a bleaching agent. This review discusses the advantages, disadvantages, regulatory concerns, flavor implications, and optimal usage conditions of 2 widely used bleaching agents, hydrogen peroxide and benzoyl peroxide, as well as a few alternative methods including lipoxygenase, peroxidase, and lactoperoxidase systems. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  6. Bio-filtration of helminth eggs and coliforms from municipal sewage for agricultural reuse in Peru

    NARCIS (Netherlands)

    Yaya Beas, R.E.

    2016-01-01

    Where fresh water resources are scarce, treated wastewater becomes an attractive alternative for agricultural irrigation. However, the presence of large amounts of pathogens, even in treated wastewater, constraints its productive use, which is aggravated when sanitation and public health are

  7. Bio-filtration of helminth eggs and coliforms from municipal sewage for agricultural reuse in Peru

    NARCIS (Netherlands)

    Yaya Beas, R.E.

    2016-01-01

    Where fresh water resources are scarce, treated wastewater becomes an attractive alternative for agricultural irrigation. However, the presence of large amounts of pathogens, even in treated wastewater, constraints its productive use, which is aggravated when sanitation and public health are poor.

  8. ICT reuse in socio-economic enterprises.

    Science.gov (United States)

    Ongondo, F O; Williams, I D; Dietrich, J; Carroll, C

    2013-12-01

    In Europe, socio-economic enterprises such as charities, voluntary organisations and not-for-profit companies are involved in the repair, refurbishment and reuse of various products. This paper characterises and analyses the operations of socio-economic enterprises that are involved in the reuse of Information and Communication Technology (ICT) equipment. Using findings from a survey, the paper specifically analyses the reuse activities of socio-economic enterprises in the U.K. from which Europe-wide conclusions are drawn. The amount of ICT products handled by the reuse organisations is quantified and potential barriers and opportunities to their operations are analysed. By-products from reuse activities are discussed and recommendations to improve reuse activities are provided. The most common ICT products dealt with by socio-economic enterprises are computers and related equipment. In the U.K. in 2010, an estimated 143,750 appliances were reused. However, due to limitations in data, it is difficult to compare this number to the amount of new appliances that entered the U.K. market or the amount of waste electrical and electronic equipment generated in the same period. Difficulties in marketing products and numerous legislative requirements are the most common barriers to reuse operations. Despite various constraints, it is clear that organisations involved in reuse of ICT could contribute significantly to resource efficiency and a circular economy. It is suggested that clustering of their operations into "reuse parks" would enhance both their profile and their products. Reuse parks would also improve consumer confidence in and subsequently sales of the products. Further, it is advocated that industrial networking opportunities for the exchange of by-products resulting from the organisations' activities should be investigated. The findings make two significant contributions to the current literature. One, they provide a detailed insight into the reuse operations

  9. Re-use of disposable coil dialysers

    International Nuclear Information System (INIS)

    Abbud Filho, M.

    1980-01-01

    Re-use of disposable dialysers has been in practice for over 16 years throughout the world but it still is a polemical subject. The main justification for it is the reduction of costs in the hemodialytic treatment. We evaluated the technique of re-use that we adopt by studying 33 patients who should re-utilize coil dialysers for 8 consecutive hemodialysis sessions. We investigated: 1) small and middle molecules clearances trough a radioisotopic method; 2) the integrity of the system regarding bacterial invasion; 3) the frequency of anti-N antibodies; 4) aspects of scanning electron microscopy (SEM) of dialysis membrane after re-use. We observed no changes in the dialysers performance during re-use. We conclude that the re-use of dialyzers is feasible, without risks for the patients, allowing marked reduction of costs, thus making possible to offer treatment to a larger number of uremic patients. (author)

  10. A bleaching earth from egyptian local deposits

    Directory of Open Access Journals (Sweden)

    El Kinawy, Omayma S.

    2001-10-01

    Full Text Available The present investigation deals with the bleaching of vegetable oils using activated clays collected from some deposits in Egypt as compared to Tonsil FF currently used by local oil industry. The comparison was made; not only on the basis of the decolourising power of the earth, but also on the basis of its effects on the oil acidity, formation of the oil peroxides and the decomposition rate of the formed peroxides to aldehydes and ketones during the bleaching process. The activation of the collected earth samples was made using 4N HCl, 6N HCl and 30 % H2SO4. The bleaching tests of the activated samples were performed using the major four oil types processed in Egypt being cottonseed, sunflower, soybean and palm oils. In addition to the laboratory-evaluation tests, the performance of the activated samples, which showed promise on the lab-scale have been also tested on an industrial scale. The industrial application has proved that the activated local earth's can be successfully used as bleaching earth of local oils. Thus it can be used as a substitute of the varieties currently imported and used by the local oil sector.La presente investigación trata de la decoloración de aceites vegetales usando tierras activadas obtenidas de yacimientos egipcios, comparándola con el Tonsil FF usado normalmente en la industria oleícola local. La comparación se realizó, no sólo sobre la base del poder decolorante de la tierra, sino también sobre la base de sus efectos en la acidez del aceite, la formación de peróxidos y la velocidad de descomposición de los peróxidos formados en aldehidos y cetonas durante el proceso de decoloración. La activación de las muestras de tierras recogidas se hizo utilizando ClH 4N, ClH 6N y H2SO4 30 %. Los tests de decoloración de las muestras activadas se llevaron a cabo usando los cuatro tipos mayoritarios de aceites procesados en Egipto: aceite de semilla de algodón, de girasol, de soja y de palma. Además de los

  11. Effect of light energy on peroxide tooth bleaching.

    Science.gov (United States)

    Luk, Karen; Tam, Laura; Hubert, Manfred

    2004-02-01

    Light-activated bleaching is a method of tooth whitening. The authors conducted a study to compare the whitening effects and tooth temperature changes induced by various combinations of peroxide bleaches and light sources. The authors randomly assigned 250 extracted human teeth halves into experimental groups (n = 10). A placebo gel (control), a 35 percent hydrogen peroxide or a 10 percent carbamide peroxide bleach was placed on the tooth surface and was irradiated with no light (control); a halogen curing light; an infrared, or IR, light; an argon laser; or a carbon dioxide, or CO2, laser. Color changes were evaluated immediately, one day and one week after treatment using a value-oriented shade guide and an electronic dental color analyzer. The outer enamel and inner dentin surface temperatures were monitored before and immediately after each 30-second application of light using a thermocouple thermometer. Color and temperature changes were significantly affected by an interaction of the bleach and light variables. The application of lights significantly improved the whitening efficacy of some bleach materials, but it caused significant temperature increases in the outer and inner tooth surfaces. The IR and CO2 laser lights caused the highest tooth temperature increases. Dentists performing an in-office bleaching technique with the use of an additional light source to accelerate tooth whitening should consider the specific bleaching agent being used, as well as the potential risks of heating teeth. A specific combination of bleach and light that demonstrates good color change and little temperature rise should be selected for in-office tooth bleaching.

  12. Intrapulpal temperature variation during bleaching with various activation mechanisms

    Directory of Open Access Journals (Sweden)

    Sílvia Masae de Araujo Michida

    2009-10-01

    Full Text Available OBJECTIVES: The aim of this study was to evaluate the intrapulpal temperature variation after bleaching treatment with 35% hydrogen peroxide using different sources of activation. MATERIAL AND METHODS: Twenty-four human teeth were sectioned in the mesiodistal direction providing 48 specimens, and were divided into 4 groups (n=12: (G1 Control - Bleaching gel without light activation, (G2 Bleaching gel + halogen light, (G3 Bleaching gel + LED, (G4 Bleaching gel + Nd:YAG Laser. The temperatures were recorded using a digital thermometer at 4 time points: before bleaching gel application, 1 min after bleaching gel application, during activation of the bleaching gel, and after the bleaching agent turned from a dark-red into a clear gel. Data were analyzed statistically by the Dunnet's test, ANOVA and Tukey's test (a=0.05. RESULTS: The mean intrapulpal temperature values (ºC in the groups were: G1: 0.617 ± 0.41; G2: 1.800 ± 0.68; G3: 0.975 ± 0.51; and G4: 4.325 ± 1.09. The mean maximum temperature variation (MTV values were: 1.5ºC (G1, 2.9ºC (G2, 1.7ºC (G3 and 6.9ºC (G4. When comparing the experimental groups to the control group, G3 was not statistically different from G1 (p>0.05, but G2 and G4 presented significantly higher (p<0.05 intrapulpal temperatures and MTV. The three experimental groups differed significantly (p<0.05 from each other. CONCLUSIONS: The Nd:YAG laser was the activation method that presented the highest values of intrapulpal temperature variation when compared with LED and halogen light. The group activated by LED light presented the lowest values of temperature variation, which were similar to that of the control group.

  13. Atmospheric Pressure Plasma Jet as an Accelerator of Tooth Bleaching.

    Science.gov (United States)

    Santak, Vedran; Zaplotnik, Rok; Milosevic, Slobodan; Klaric, Eva; Tarle, Zrinka

    2014-12-01

    To study the effect of atmospheric pressure plasma (APP) jet as a potential accelerator of the degradation of hydrogen peroxide in bleaching gels which could lead to better and faster bleaching. 25 pastilles of hydroxylapatite were colored in green tea for 8 hours and were randomly divided into five groups (n = 5). The bleaching process was performed with 30% and 40% hydrogen peroxide (HP) gel alone and in conjunction with helium APP jet. During the bleaching treatment, optical emission spectroscopy and non-contact surface temperature measurement using pyrometer were performed. Color of the pastilles was determined by a red-green-blue (RGB) colorimeter. PH values of bleaching gels were measured before and after the plasma treatment on additional 10 pastilles using a pH meter with contact pH electrode. The color measurements of pastilles before and after the treatment showed that treatment with APP jet improved the bleaching effect by 32% and 15% in the case of 30% and 40% HP gel. Better results were obtained approximately six times faster than with a procedure suggested by the bleaching gel manufacturer. Optical emission spectroscopy proved that plasma has a chemically active role on the gel. After the APP treatment, pH values of bleaching gels dropped to about 50-75% of their initial value while the surface temperature increased by 8-10˚C above baseline. The use of plasma jet provides more effective bleaching results in a shorter period of time without a significant temperature increase which may cause damage of the surrounding tissue.

  14. Some observations on air filtration

    NARCIS (Netherlands)

    Kluyver, A.J.; Visser, J.

    1950-01-01

    1. A method has been developed for testing the filtration efficiency of some filter materials. For each of the materials investigated — cotton wool, stillite and carbon — a suitable filter has been devised. 2. The filtered air was analyzed as to its germ content with the aid of a set of 3 capillary

  15. Bleaching and diffusion dynamics in optofluidic dye lasers

    DEFF Research Database (Denmark)

    Gersborg-Hansen, Morten; Balslev, Søren; Mortensen, Asger

    2007-01-01

    The authors have investigated the bleaching dynamics that occur in optofluidic dye lasers where the liquid laser dye in a microfluidic channel is locally bleached due to optical pumping. They find that for microfluidic devices, the dye bleaching may be compensated through diffusion of dye molecules...... alone. By relying on diffusion rather than convection to generate the necessary dye replenishment, their observation potentially allows for a significant simplification of optofluidic dye laser device layouts, omitting the need for cumbersome and costly external fluidic handling or on-chip microfluidic...

  16. A Comparison Between Alkali Peroxide and Activated Peroxide Processes in Bleaching Hardwoods Chemi-mechanical Pulp

    Directory of Open Access Journals (Sweden)

    Farhad Zeyni

    2013-06-01

    Full Text Available Unbleached chemi-mechanical pulp of 85% pulp yield and produced from hornbeam, beech and populus woods respectively by 3:1:1 ratio, was used for peroxide bleaching. Two bleaching systems, alkali peroxide (conventional bleaching and activated peroxide by TAED activator, were used for pulp bleaching. Bleaching treatments included different percentages of hydrogen peroxide and caustic soda consumption. In this research, the hydrogen peroxide consumption rate, pulp yield, process selectivity, bleached pulp brightness and bleaching effluent pollution load (COD were investigated. Results showed that, brightness values were increased by bleach chemicals charge rising, in both bleaching systems, but the increasing trend was downward. Also, pulp yield was decreased by increase of chemical charges, but residual peroxide was raised. The activated peroxide process compare to conventional process had lower efficiency and brightness improvement values of pulp were less than those of alkali peroxide process. But pulp yield and effluent pollution load was less by activated peroxide bleaching.

  17. Flotation of Toxocara canis Eggs in Commercial Bleach and Effects of Bleach Treatment Times on Larval Development in These Eggs.

    Science.gov (United States)

    von Dohlen, Alexa Rosypal; Houk-Miles, Alice E; Zajac, Anne M; Lindsay, David S

    2017-04-01

    Toxocara canis is a common intestinal nematode of young dogs. Puppies contaminate the environment with large numbers of eggs that can embryonate and become infective in less than a month. Embryonated eggs are infectious for humans and other paratenic hosts. Most T. canis infections in humans are asymptomatic; however, migration of T. canis larvae in the eye and in the central nervous system can result in vision loss, blindness, and even death. The eggs of T. canis are highly resistant to harsh environmental conditions and routinely used chemical disinfectants. The objective of this study was to evaluate the effects of full-strength commercial bleach (5.25% sodium hypochlorite solution) treatment on development of T. canis eggs and to report our serendipitous finding that T. canis eggs in dog feces can float in passive fecal flotation tests using bleach. We also demonstrated that T. canis eggs could be identified using the McMaster's fecal eggs counting test using 100% bleach. Toxocara canis eggs collected from the feces of naturally infected 4-8 wk old puppies were treated with full-strength bleach (5.25% sodium hypochlorite solution) for 15 min, 30 min, 60 min, and 120 min; washed free of bleach smell by centrifugation; and resuspended in 0.1 N sulfuric acid solution to undergo larval development at room temperature for 18 days after exposure to bleach. Motile larvae were observed in T. canis eggs in all groups treated for 15-120 min and eggs continuously exposed to bleach for 18 days. Our results indicate that bleach may not be an appropriate disinfectant for dog kennels, cages, or laboratory utensils and work surfaces. Toxocara canis eggs are resistant to bleach treatment and continue to pose a risk for canine and human infections. Further study is needed to find the most appropriate methods for disinfection and removal of eggs to reduce the risk of transmission of this parasite.

  18. Improvement in rice straw pulp bleaching effluent quality by incorporating oxygen delignification stage prior to elemental chlorine-free bleaching.

    Science.gov (United States)

    Kaur, Daljeet; Bhardwaj, Nishi K; Lohchab, Rajesh Kumar

    2017-10-01

    Environmental degradation by industrial and other developmental activities is alarming for imperative environmental management by process advancements of production. Pulp and paper mills are now focusing on using nonwood-based raw materials to protect forest resources. In present study, rice straw was utilized for pulp production as it is easily and abundantly available as well as rich in carbohydrates (cellulose and hemicelluloses). Soda-anthraquinone method was used for pulp production as it is widely accepted for agro residues. Bleaching process during paper production is the chief source of wastewater generation. The chlorophenolic compounds generated during bleaching are highly toxic, mutagenic, and bioaccumulative in nature. The objectives of study were to use oxygen delignification (ODL) stage prior to elemental chlorine-free (ECF) bleaching to reduce wastewater load and to study its impact on bleached pulp characteristics. ODL stage prior to ECF bleaching improved the optical properties of pulp in comparison to only ECF bleaching. When ODL stage was incorporated prior to bleaching, the tensile index and folding endurance of the pulp were found to be 56.6 ± 1.5 Nm/g and 140, respectively, very high in comparison to ECF alone. A potential reduction of 51, 57, 43, and 53% in BOD 3 , COD, color, and AOX, respectively was observed on adding the ODL stage compared to ECF only. Generation of chlorophenolic compounds was reduced significantly. Incorporation of ODL stage prior to bleaching was found to be highly promising for reducing the toxicity of bleaching effluents and may lead to better management of nearby water resources. Graphical abstract ᅟ.

  19. Filtration Understanding: FY10 Testing Results and Filtration Model Update

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Richard C.; Billing, Justin M.; Burns, Carolyn A.; Peterson, Reid A.; Russell, Renee L.; Schonewill, Philip P.; Shimskey, Rick W.

    2011-04-04

    This document completes the requirements of Milestone 2-4, Final Report of FY10 Testing, discussed in the scope of work outlined in the EM31 task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to improve filtration and cleaning efficiencies, thereby increasing process throughput and reducing the Na demand (through acid neutralization). Developing the cleaning/backpulsing requirements will produce much more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby significantly increasing throughput by limiting cleaning cycles. The scope of this work is to develop the understanding of filter fouling to allow developing this cleaning/backpulsing strategy.

  20. Evaluation of the bleached human enamel by Scanning Electron Microscopy

    DEFF Research Database (Denmark)

    Miranda, Carolina Baptista; Pagani, Clovis; Benetti, Ana Raquel

    2005-01-01

    Since bleaching has become a popular procedure, the effect of peroxides on dental hard tissues is of great interest in research. Purpose: The aim of this in vitro study was to perform a qualitative analysis of the human enamel after the application of in-office bleaching agents, using Scanning...... analysis performing gold sputter coating under vacuum and were examined using 15kV at 500x and 2000x magnification. Results: Morphological alterations on the enamel surface were similarly detected after bleaching with either 35% carbamide peroxide or 35% hydrogen peroxide. Surface porosities were...... characteristic of an erosive process that took place on human enamel. Depression areas, including the formation of craters, and exposure of enamel rods could also be detected. Conclusion: Bleaching effects on enamel morphology were randomly distributed throughout enamel surface and various degrees of enamel...

  1. Bleaching of hydroentangled greige cotton nonwoven fabrics without scouring

    Science.gov (United States)

    This work investigated whether a hydroentangled greige cotton nonwoven fabric made at a relatively high hydroentangling water pressure, say, 135-bar, could be successfully bleached to attain the desired whiteness, absorbency and other properties without traditional scouring. Accordingly, the scoured...

  2. Filtrations of free groups as intersections

    OpenAIRE

    Efrat, Ido

    2013-01-01

    For several natural filtrations of a free group S we express the n-th term of the filtration as the intersection of all kernels of homomorphisms from S to certain groups of upper-triangular unipotent matrices. This generalizes a classical result of Grun for the lower central filtration. In particular, we do this for the n-th term in the lower p-central filtration of S.

  3. Thermal refugia against coral bleaching throughout the northern Red Sea

    KAUST Repository

    Osman, Eslam O.

    2017-10-17

    Tropical reefs have been impacted by thermal anomalies caused by global warming that induced coral bleaching and mortality events globally. However, there have only been very few recordings of bleaching within the Red Sea despite covering a latitudinal range of 15° and consequently it has been considered a region that is less sensitive to thermal anomalies. We therefore examined historical patterns of sea surface temperature (SST) and associated anomalies (1982–2012) and compared warming trends with a unique compilation of corresponding coral bleaching records from throughout the region. These data indicated that the northern Red Sea has not experienced mass bleaching despite intensive Degree Heating Weeks (DHW) of >15°C-weeks. Severe bleaching was restricted to the central and southern Red Sea where DHWs have been more frequent, but far less intense (DHWs <4°C-weeks). A similar pattern was observed during the 2015–2016 El Niño event during which time corals in the northern Red Sea did not bleach despite high thermal stress (i.e. DHWs >8°C-weeks), and bleaching was restricted to the central and southern Red Sea despite the lower thermal stress (DHWs < 8°C-weeks). Heat stress assays carried out in the northern (Hurghada) and central (Thuwal) Red Sea on four key reef-building species confirmed different regional thermal susceptibility, and that central Red Sea corals are more sensitive to thermal anomalies as compared to those from the north. Together, our data demonstrate that corals in the northern Red Sea have a much higher heat tolerance than their prevailing temperature regime would suggest. In contrast, corals from the central Red Sea are close to their thermal limits, which closely match the maximum annual water temperatures. The northern Red Sea harbours reef-building corals that live well below their bleaching thresholds and thus we propose that the region represents a thermal refuge of global importance.

  4. Effect of a New Bleaching Gel on Tooth Whitening

    Science.gov (United States)

    2016-05-12

    Effect of a New Bleaching Gel on Tooth Whitening Maj Tonya N. Barry APPROVED: Date APPROVED: Dean, Air Force Post aduate Dental School...UNIFORMED SERVICES UNIVERSITY OF THE HEALTH SCIENCES AIR FORCE POSTGRADUATE DENTAL SCHOOL 2450 Pepperrell Street Lackland AFB Texas, 78236-5345 http...reduced chair time and cost, high success rate, and safety of materials.6 2 Furthermore, bleaching teeth with 10% carbamide peroxide (the

  5. Reuse of Hydrotreating Spent Catalyst

    International Nuclear Information System (INIS)

    Habib, A.M.; Menoufy, M.F.; Amhed, S.H.

    2004-01-01

    All hydro treating catalysts used in petroleum refining processes gradually lose activity through coking, poisoning by metal, sulfur or halides or lose surface area from sintering at high process temperatures. Waste hydrotreating catalyst, which have been used in re-refining of waste lube oil at Alexandria Petroleum Company (after 5 years lifetime) compared with the same fresh catalyst were used in the present work. Studies are conducted on partial extraction of the active metals of spent catalyst (Mo and Ni) using three leaching solvents,4% oxidized oxalic acid, 10% aqueous sodium hydroxide and 10% citric acid. The leaching experiments are conducting on the de coked extrude [un crushed] spent catalyst samples. These steps are carried out in order to rejuvenate the spent catalyst to be reused in other reactions. The results indicated that 4% oxidized oxalic acid leaching solution gave total metal removal 45.6 for de coked catalyst samples while NaOH gave 35% and citric acid gave 31.9 % The oxidized leaching agent was the most efficient leaching solvent to facilitate the metal removal, and the rejuvenated catalyst was characterized by the unchanged crystalline phase The rejuvenated catalyst was applied for hydrodesulfurization (HDS) of vacuum gas oil as a feedstock, under different hydrogen pressure 20-80 bar in order to compare its HDS activity

  6. DECONTAMINATION TECHNOLOGIES FOR FACILITY REUSE

    International Nuclear Information System (INIS)

    Bossart, Steven J.; Blair, Danielle M.

    2003-01-01

    As nuclear research and production facilities across the U.S. Department of Energy (DOE) nuclear weapons complex are slated for deactivation and decommissioning (D and D), there is a need to decontaminate some facilities for reuse for another mission or continued use for the same mission. Improved technologies available in the commercial sector and tested by the DOE can help solve the DOE's decontamination problems. Decontamination technologies include mechanical methods, such as shaving, scabbling, and blasting; application of chemicals; biological methods; and electrochemical techniques. Materials to be decontaminated are primarily concrete or metal. Concrete materials include walls, floors, ceilings, bio-shields, and fuel pools. Metallic materials include structural steel, valves, pipes, gloveboxes, reactors, and other equipment. Porous materials such as concrete can be contaminated throughout their structure, although contamination in concrete normally resides in the top quarter-inch below the surface. Metals are normally only contaminated on the surface. Contamination includes a variety of alpha, beta, and gamma-emitting radionuclides and can sometimes include heavy metals and organic contamination regulated by the Resource Conservation and Recovery Act (RCRA). This paper describes several advanced mechanical, chemical, and other methods to decontaminate structures, equipment, and materials

  7. Modeling bleaching of tomato derivatives at subzero temperatures.

    Science.gov (United States)

    Manzocco, Lara; Calligaris, Sonia; Nicoli, Maria Cristina

    2006-02-22

    This work was addressed to obtain a predictive model of the rate of bleaching in tomato derivatives at subzero temperatures. To this aim, a tomato puree was freeze-dried and equilibrated at increasing solid fractions. The bleaching rate was assessed by measuring tomato color during storage for up to 18 months at temperatures from -30 to 0 degrees C. The temperature dependence of the tomato-bleaching rate was neither predictable using the Arrhenius equation nor simply related to tomato physical state. The lack of a clear Arrhenius relation was attributed to the occurrence of temperature-dependent phenomena, such as ice crystallization and oxygen solubility modifications, which strongly changed the local concentration of reactants. A modified Arrhenius equation predicting the tomato-bleaching rate in the entire temperature range was proposed. Tomato concentration, and hence its physical state, affected the temperature dependence of bleaching, modifying apparent activation energy and frequency factor of the modified Arrhenius equation. In light of these considerations, a mathematical model was set up and validated to accurately predict the tomato-bleaching rate on the basis of only its concentration and storage temperature.

  8. An empirical analysis of ontology reuse in BioPortal.

    Science.gov (United States)

    Ochs, Christopher; Perl, Yehoshua; Geller, James; Arabandi, Sivaram; Tudorache, Tania; Musen, Mark A

    2017-07-01

    Biomedical ontologies often reuse content (i.e., classes and properties) from other ontologies. Content reuse enables a consistent representation of a domain and reusing content can save an ontology author significant time and effort. Prior studies have investigated the existence of reused terms among the ontologies in the NCBO BioPortal, but as of yet there has not been a study investigating how the ontologies in BioPortal utilize reused content in the modeling of their own content. In this study we investigate how 355 ontologies hosted in the NCBO BioPortal reuse content from other ontologies for the purposes of creating new ontology content. We identified 197 ontologies that reuse content. Among these ontologies, 108 utilize reused classes in the modeling of their own classes and 116 utilize reused properties in class restrictions. Current utilization of reuse and quality issues related to reuse are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Demonstration of creep during filtration

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Bugge, Thomas Vistisen; Kirchheiner, Anders Løvenbalk

    that the production of filtrate also depends on the characteristic time for the filter cake solids to deform. This is formulated in the Terzaghi-Voigt model in which a secondary consolidation is introduced. The secondary consolidation may be visualized by plots of the relative cake deformation (U) v.s. the square...... root of time. Even more clearly it is demonstrated by plotting the liquid pressure at the cake piston interface v.s. the relative deformation (to be shown). The phenomenon of a secondary consolidation processes is in short called creep. Provided that the secondary consolidation rate is of the same......The classical filtration theory assumes a unique relationship between the local filter cake porosity and the local effective pressure. For a number of compressible materials, it has however been observed that during the consolidation stage this may not be the case. It has been found...

  10. Filtration resistances of nickel carbonate

    Directory of Open Access Journals (Sweden)

    Jorge Rafael Gutiérrez-Olmos

    2017-12-01

    Full Text Available In the present work, the filtration of nickel carbonate was studied experimentally to laboratory scale, to evaluate the effects of suspension pH, chemical composition and fineness of the salt over of specific cake resistance and the medium resistance. The filtration was realized to a temperature of 80 ºC, 16 % in weight of solids and constant pressure drop of 3,758.104 N/m, applying as membrane the Kraft paper. It was obtained that by increasing the concentration of carbon dioxide on salt (1, 9 to 4, 4 %, it diminishes the content of sulphur (3, 09 to 1, 84 % and the specific cake resistance. It was showed the pH’s range for the minimum of specific resistance and cake humidity; when the pH increases from 7, 40 to 8, 76, increment the concentration of solids in the filtrate from 38 to 105 mg/l. To smallest pH than 7, 82, the inferior values of average particle diameter (dp was obtained; and the specific cake resistance incremented due to the combined effect between the variables: Concentration of carbon dioxide in salt, the pH of the suspension and dp. A model to estimate the specific cake resistance were proposed.

  11. Reusing Property Resulting from Analytical Laboratory Closure

    International Nuclear Information System (INIS)

    Elmer, J.; DePinho, D.; Wetherstein, P.

    2006-01-01

    The U.S. Department of Energy Office of Legacy Management (DOE-LM) site in Grand Junction, Colorado, faced the problem of reusing an extensive assortment of laboratory equipment and supplies when its on-site analytical chemistry laboratory closed. This challenge, undertaken as part of the Grand Junction site's pollution prevention program, prioritized reuse of as much of the laboratory equipment and supplies as possible during a 9-month period in fiscal year 2004. Reuse remedies were found for approximately $3 million worth of instrumentation, equipment, chemicals, precious metals, and other laboratory items through other Grand Junction site projects, Federal Government databases, and extensive contact with other DOE facilities, universities, and colleges. In 2005, the DOE-LM Grand Junction site received two prestigious DOE pollution prevention awards for reuse of the laboratory's equipment and supplies. (authors)

  12. Software Reuse in the Naval Open Architecture

    National Research Council Canada - National Science Library

    Greathouse, Carlus A

    2008-01-01

    This thesis describes a web-based continuous learning module (CLM) for use in introducing members of the Department of the Navy s acquisition community to software reuse in the context of Naval Open Architecture...

  13. Effluent treatment by multi-media filtration, microfiltration and ultrafiltration: results of a pilot investigation at WWTP Hoek van Holland.

    Science.gov (United States)

    te Poele, S; Menkveld, W; Boom, J; van Bragt, W

    2005-01-01

    Upgrading of wastewater treatment plant (WWTP) effluent as a part of the Dutch governmental policy to close the water cycle has increasing interest now. The Water Board Hoogheemraadschap van Delfland together with the project team of Witteveen + Bos Consulting Engineers, Delft University of Technology and Rossmark water treatment investigated the reuse possibilities of WWTP effluent in the region of Delfland. Therefore pilot research was carried out at WWTP Hoek van Holland applying different filtration techniques: multi-media filtration, micro- and ultrafiltration. The results show stable process performances of the different filtration techniques when proper pre-treatment was applied. For microfiltration the filtration characteristics were strongly influenced by particles which were not retained in the multi-media filter. For ultrafiltration the filtration characteristics were strongly influenced by organic components WWTP effluent could not be used directly as process water or for agriculture purposes, due to high concentrations of COD and salts in the WWTP effluent and filtrates. However WWTP effluent or floc filtrate could be applied directly as water for the washing of sea-sand.

  14. 'Ethnic cleansing' bleaches the atrocities of genocide.

    Science.gov (United States)

    Blum, Rony; Stanton, Gregory H; Sagi, Shira; Richter, Elihu D

    2008-04-01

    Genocide has been the leading cause of preventable violent death in the 20th-21st century, taking even more lives than war. The term 'ethnic cleansing' is used as a euphemism for genocide despite it having no legal status. Like 'Judenrein' and 'racial hygiene' in Nazi medicine, it expropriates pseudo-medical terminology to justify massacre. Use of the term reifies a dehumanized view of the victims as sources of filth and disease, and propagates the reversed social ethics of the perpetrators. Timelines for recent genocides (Bosnia, 1991-1996, 200,000; Kosovo 1998-2000, 10,000-20,000; Rwanda, 1994, 800,000; Darfur 2002-2006, >400,000) show that its use bears no relationship to death tolls or the scale of atrocity. Bystanders' use of the term 'ethnic cleansing' signals the lack of will to stop genocide, resulting in huge increases in deaths, and undermines international legal obligations to acknowledge genocide. The term 'ethnic cleansing' corrupts observation, interpretation, ethical judgment and decision-making, thereby undermining the aim of public health. Public health should lead the way in expunging the term 'ethnic cleansing' from official use. 'Ethnic cleansing' bleaches the atrocities of genocide, leading to inaction in preventing current and future genocides.

  15. Clinical Evaluation of Genotoxicity of In-office Bleaching.

    Science.gov (United States)

    Rezende, M; De Geus, J L; Loguercio, A D; Reis, A; Kossatz, D

    The aim of this study was to evaluate the genotoxicity of in-office bleaching with 35% hydrogen peroxide in epithelial cells from the gingival and lip tissues. Thirty volunteers with central incisors shade A1 or darker were selected for this study. The gingival tissue of the teeth to be bleached was isolated with a light-polymerized resin dam, and the 35% hydrogen peroxide gel was administered during three 15-minute applications over the course of the 45-minute application period. Two bleaching sessions with a one-week interval in between were performed. Exfoliated oral mucosa gingival epithelial cells and upper lip lining were collected at baseline and one month after the in-office dental bleaching. The scraped cells were placed on clean glass slides and smears were prepared. After staining with Giemsa solution, two blinded examiners performed cell and micronuclei counts under a 100× optical microscope. Tooth sensitivity was evaluated using the Visual Analogue Scale (VAS). Shade evaluation was recorded before and one month after the bleaching treatment with the value-oriented shade guide Vita Bleachedguide 3D-MASTER and the spectrophotometer Vita Easyshade. Data from the shade guide units and the micronuclei (MN) frequency were subjected to a Mann-Whitney test (α=0.05). The overall difference between before and one month after the bleaching treatment (ΔE and ΔSGU), absolute risk, and intensity of tooth sensitivity (TS) were calculated, as was the 95% confidence interval (CI). The frequency of MN was not increased after bleaching with 35% hydrogen peroxide in both study groups (p>0.05). The absolute risk of TS of the participants was 93% (95% CI, 79%-98%), with a mean VAS intensity of 5.7 ± 2.9 (95% CI, 4.6-6.8). Meaningful whitening was observed after bleaching. The change in shade guide units in the Bleachedguide 3D-MASTER was 2.3 ± 1.4. In terms of ΔE, the change in color was 7.7 ± 3.5. The in-office bleaching did not induce DNA damage to the gingival

  16. Quantifying bleaching for zero-age fluvial sediment: A Bayesian approach

    International Nuclear Information System (INIS)

    Cunningham, Alastair C.; Evans, Mary; Knight, Jasper

    2015-01-01

    Luminescence dating of sediment requires the sand grains to have been exposed to sunlight prior to their most recent burial. Under fluvial transport, the amount of sunlight exposure may not always be sufficient to reset the luminescence signal, a phenomenon known as ‘partial bleaching'. The extent of bleaching is dependent on a combination of geomorphic, sedimentological and fluvial processes. If bleaching can be quantified, and the relationship with these processes understood, it could potentially be used as a new environmental proxy for changes in the dynamics of river systems. Here, we use a recently developed statistical model to evaluate the extent of bleaching, by inferring the proportion of well-bleached grains in the small-aliquot population. We sampled low-flow and flood deposits at a single site on the River Sabie, South Africa. We show that the low-flow sediment is almost perfectly bleached (>80% of grains well bleached), while sediment at flood elevations is partially bleached (20–70 % of grains well bleached). The degree of bleaching may show a relationship with flood magnitude as defined by elevation above normal river level, and we speculate on the causes of variability in bleaching between flood samples. - Highlights: • We sampled modern river sediment from low-flow and flood elevations. • The unbleached OSL dose was measured. • Bayesian methods can estimate the proportion of well-bleached grains. • Low-flow sediments are well bleached; flood deposits are poorly bleached.

  17. Reuse metrics and measurement: A framework

    Science.gov (United States)

    Reifer, Donald J.

    1990-01-01

    The lessons learned and experience gleaned are described by those who have started to implement the reuse metrics and measurement framework used in controlling the development of common avionics and software for its affiliated aircraft programs. The framework was developed to permit the measurement of the long term cost/benefits resulting from the creation and use of Reusable Software Objects (RSOs). The framework also monitors the efficiency and effectiveness of the Software Reuse Library (SRL). The metrics and measurement framework is defined which was established to allow some determinations and findings to be made relative to software reuse. Seven criteria are discussed which were used to guide the establishment of the proposed reuse framework. Object recapture and creation metrics are explained along with their normalized use in effort, productivity, and quality determination. A single and multiple reuse instance version of a popular cost model is presented which uses these metrics and the measurement scheme proposed to predict the software effort and duration under various reuse assumptions. Studies in using this model to predict actuals taken from the RCI data base of over 1000 completed projects is discussed.

  18. Nitroxide free radicals protect macular carotenoids against chemical destruction (bleaching) during lipid peroxidation.

    Science.gov (United States)

    Zareba, M; Widomska, J; Burke, J M; Subczynski, W K

    2016-12-01

    Macular xanthophylls (MXs) lutein and zeaxanthin are dietary carotenoids that are selectively concentrated in the human eye retina, where they are thought to protect against age-related macular degeneration (AMD) by multiple mechanisms, including filtration of phototoxic blue light and quenching of singlet oxygen and triplet states of photosensitizers. These physical protective mechanisms require that MXs be in their intact structure. Here, we investigated the protection of the intact structure of zeaxanthin incorporated into model membranes subjected to oxidative modification by water- and/or membrane-soluble small nitroxide free radicals. Model membranes were formed from saturated, monounsaturated, and polyunsaturated phosphatidylcholines (PCs). Oxidative modification involved autoxidation, iron-mediated, and singlet oxygen-mediated lipid peroxidation. The extent of chemical destruction (bleaching) of zeaxanthin was evaluated from its absorption spectra and compared with the extent of lipid peroxidation evaluated using the thiobarbituric acid assay. Nitroxide free radicals with different polarity (membrane/water partition coefficients) were used. The extent of zeaxanthin bleaching increased with membrane unsaturation and correlated with the rate of PC oxidation. Protection of the intact structure of zeaxanthin by membrane-soluble nitroxides was much stronger than that by water-soluble nitroxides. The combination of zeaxanthin and lipid-soluble nitroxides exerted strong synergistic protection against singlet oxygen-induced lipid peroxidation. The synergistic effect may be explained in terms of protection of the intact zeaxanthin structure by effective scavenging of free radicals by nitroxides, therefore allowing zeaxanthin to quench the primary oxidant, singlet oxygen, effectively by the physical protective mechanism. The redox state of nitroxides was monitored using electron paramagnetic resonance spectroscopy. Both nitroxide free radicals and their reduced form

  19. Tooth Whitening And Temperature Rise With Two Bleaching Activation Methods

    Science.gov (United States)

    Abu-ElMagd, D. M.; El-Sayad, I. I.; Abd El-Gawad, L. M.

    2009-09-01

    To measure the tooth whitening and the surface and Intrapulpal temperature increase in vitro on freshly extracted upper human central incisors after chemical, Zoom AP light and diode laser activated bleaching. Thirty caries-free upper human incisors were selected. Teeth were divided into three equal groups according to the methods of activation of the bleaching agent (n = 10). A whitening gel containing hydrogen peroxide was applied to the buccal surface of all teeth. Group I was bleached using chemically activated hydrogen peroxide gel, for three applications of 15 min each. Group II was bleached with high intensity advanced power Zoom activation light (Zoom AP), for three applications of 15 min each. Group III was bleached with diode laser activation technique, where the teeth were irradiated with 2 Watt diode laser for three applications of 30 sec each. The whitening degree was assessed using an image analysis system, while temperature rise was recorded using a thermocouple on the external tooth surface and Intrapulpal. The degree of whitening increased significantly in all groups. However, the percentage of whitening was not statistically significantly different between the three groups. In addition, group II showed statistically significant higher mean rise in both surface and pulp temperatures than group I and group III. Chemical bleaching produces the same whitening effect as Zoom AP light and laser, with no surface or pulpal temperature rise. Laser application is faster and produces less surface and pulp temperature increase than Zoom AP light. Diode laser used to activate bleaching gels is not considered dangerous to the vitality of dental pulp using power settings of 2 W.

  20. Software Reuse Within the Earth Science Community

    Science.gov (United States)

    Marshall, James J.; Olding, Steve; Wolfe, Robert E.; Delnore, Victor E.

    2006-01-01

    Scientific missions in the Earth sciences frequently require cost-effective, highly reliable, and easy-to-use software, which can be a challenge for software developers to provide. The NASA Earth Science Enterprise (ESE) spends a significant amount of resources developing software components and other software development artifacts that may also be of value if reused in other projects requiring similar functionality. In general, software reuse is often defined as utilizing existing software artifacts. Software reuse can improve productivity and quality while decreasing the cost of software development, as documented by case studies in the literature. Since large software systems are often the results of the integration of many smaller and sometimes reusable components, ensuring reusability of such software components becomes a necessity. Indeed, designing software components with reusability as a requirement can increase the software reuse potential within a community such as the NASA ESE community. The NASA Earth Science Data Systems (ESDS) Software Reuse Working Group is chartered to oversee the development of a process that will maximize the reuse potential of existing software components while recommending strategies for maximizing the reusability potential of yet-to-be-designed components. As part of this work, two surveys of the Earth science community were conducted. The first was performed in 2004 and distributed among government employees and contractors. A follow-up survey was performed in 2005 and distributed among a wider community, to include members of industry and academia. The surveys were designed to collect information on subjects such as the current software reuse practices of Earth science software developers, why they choose to reuse software, and what perceived barriers prevent them from reusing software. In this paper, we compare the results of these surveys, summarize the observed trends, and discuss the findings. The results are very

  1. Anaerobic biodegradability and toxicity of wastewaters from chlorine and total chlorine-free bleaching of eucalyptus kraft pulps.

    NARCIS (Netherlands)

    Vidal, G.; Soto, M.; Field, J.; Mendez-Pampin, R.; Lema, J.M.

    1997-01-01

    Chlorine bleaching effluents are problematic for anaerobic wastewater treatment due to their high methanogenic toxicity and low biodegradability. Presently, alternative bleaching processes are being introduced, such as elemental chlorine-free (ECF) and total chlorine-free (TCF) bleaching. The

  2. Measurement of glomerular filtration rate

    International Nuclear Information System (INIS)

    D'haene, E.G.M.

    1987-01-01

    Discussed are various methods for measuring the glomerular filtration rate in men. The unsuitability of the creatinine clearance is again emphasized. Based on comparative studies of Fawdry et al, it is stated that using the single-shot single sample methods by using theoretical distribution volumes is the obvious technique. In Dordrecht a program is developed based on the work of Tauxe et al on the analogy of the program for ERPF determination. Some patient studies are demonstrated. The GFR determination has some disadvantages however there are indications that by using the Captopril test the GFR determination is preferred above the ERPF measurement. 11 refs.; 6 figs.; 4 tabs

  3. AFM analysis of bleaching effects on dental enamel microtopography

    Energy Technology Data Exchange (ETDEWEB)

    Pedreira de Freitas, Ana Carolina, E-mail: anacarolfreitas@usp.br [Departamento de Dentistica, Faculdade de Odontologia da Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 2227 - Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil); Cardoso Espejo, Luciana, E-mail: luespejo@hotmail.com [Departamento de Dentistica, Faculdade de Odontologia da Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 2227 - Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil); Brossi Botta, Sergio, E-mail: sbbotta@usp.br [Departamento de Dentistica, Faculdade de Odontologia da Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 2227 - Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil); Sa Teixeira, Fernanda de, E-mail: nandast@if.usp.br [Laboratorio de Filmes Finos, Instituto de Fisica da Universidade de Sao Paulo, Rua do Matao, Travessa R, 187 - Cidade Universitaria, CEP 05314-970, Sao Paulo (Brazil); Cerqueira, Luz Maria Aparecida A., E-mail: maacluz@usp.br [Departamento de Dentistica, Faculdade de Odontologia da Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 2227 - Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil); Garone-Netto, Narciso, E-mail: ngarone@usp.br [Departamento de Dentistica, Faculdade de Odontologia da Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 2227 - Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil); Bona Matos, Adriana, E-mail: bona@usp.br [Departamento de Dentistica, Faculdade de Odontologia da Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 2227 - Cidade Universitaria, CEP 05508-000, Sao Paulo (Brazil); Barbosa da Silveira Salvadori, Maria Cecilia, E-mail: mcsalva@if.usp.br [Laboratorio de Filmes Finos, Instituto de Fisica da Universidade de Sao Paulo, Rua do Matao, Travessa R, 187 - Cidade Universitaria, CEP 05314-970, Sao Paulo (Brazil)

    2010-02-15

    The purpose of this in vitro study was to test a new methodology to evaluate the effects of 35% hydrogen peroxide agent on the microtopography of sound enamel using an atomic force microscope (AFM). The buccal sound surfaces of three extracted human lower incisors were used, without polishing the surfaces to maintain them with natural morphology. These unpolished surfaces were subjected to bleaching procedure with 35% hydrogen peroxide that consisted of 4 applications of the bleaching agent on enamel surfaces for 10 min each application. Surface images were obtained in a 15 {mu}m x 15 {mu}m area using an AFM. The roughness (Ra and RMS) and the power spectral density (PSD) were obtained before and after the bleaching treatment. As results we could inquire that the PSD analyses were very suitable to identifying the morphological changes on the surfaces, while the Ra and RMS parameters were insufficient to represent the morphological alterations promoted by bleaching procedure on enamel. The morphological wavelength in the range of visible light spectrum (380-750 nm) was analyzed, showing a considerable increase of the PSD with the bleaching treatment.

  4. Bacteria associated with the bleached and cave coral Oculina patagonica.

    Science.gov (United States)

    Koren, Omry; Rosenberg, Eugene

    2008-04-01

    The relative abundance of bacteria in the mucus and tissues of Oculina patagonica taken from bleached and cave (azooxanthellae) corals was determined by analyses of the 16S rRNA genes from cloned libraries of extracted DNA and from isolated colonies. The results were compared to previously published data on healthy O. patagonica. The bacterial community of bleached, cave, and healthy corals were completely different from each other. A tight cluster (>99.5% identity) of bacteria, showing 100% identity to Acinetobacter species, dominated bleached corals, comprising 25% of the 316 clones sequenced. The dominant bacterial cluster found in cave corals, representing 29% of the 97 clones sequenced, showed 98% identity to an uncultured bacterium from the Great Barrier Reef. Vibrio splendidus was the most dominant species in healthy O. patagonica. The culturable bacteria represented 0.1-1.0% of the total bacteria (SYBR Gold staining) of the corals. The most abundant culturable bacteria in bleached, cave, and healthy corals were clusters that most closely matched Microbulbifer sp., an alpha-proteobacterium previously isolated from healthy corals and an alpha-protobacterium (AB026194), respectively. Three generalizations emerge from this study on O. patagonica: (1) More bacteria are associated with coral tissue than mucus; (2) tissue and mucus populations are different; (3) bacterial populations associated with corals change dramatically when corals lack their symbiotic zooxanthellae, either as a result of the bleaching disease or when growing in the absence of light.

  5. Nonwoven filtration mat production by electrospinning method

    Science.gov (United States)

    Lackowski, M.; Krupa, A.; Jaworek, A.

    2011-06-01

    The filtration of nanoparticles and submicron particles is an important problem in industry and health protection. One of the methods which can be used to solve this problem is to use nonwoven nanofibrous filters. The process of producing filtration mats of different thickness by electrospinning is presented in the paper. The experimental results on filtration properties of nanofibrous filter mat, including the efficiency of removal of cigarette smoke particles from a gas are also presented.

  6. Nonwoven filtration mat production by electrospinning method

    Energy Technology Data Exchange (ETDEWEB)

    Lackowski, M; Krupa, A; Jaworek, A, E-mail: mala@imp.gda.pl [Institute of Fluid Flow Machinery, Polish Academy of Sciences, Fiszera 14, 80-952 Gdansk (Poland)

    2011-06-23

    The filtration of nanoparticles and submicron particles is an important problem in industry and health protection. One of the methods which can be used to solve this problem is to use nonwoven nanofibrous filters. The process of producing filtration mats of different thickness by electrospinning is presented in the paper. The experimental results on filtration properties of nanofibrous filter mat, including the efficiency of removal of cigarette smoke particles from a gas are also presented.

  7. Side Stream Filtration for Cooling Towers

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-10-20

    This technology evaluation assesses side stream filtration options for cooling towers, with an objective to assess key attributes that optimize energy and water savings along with providing information on specific technology and implementation options. This information can be used to assist Federal sites to determine which options may be most appropriate for their applications. This evaluation provides an overview of the characterization of side stream filtration technology, describes typical applications, and details specific types of filtration technology.

  8. Nonwoven filtration mat production by electrospinning method

    International Nuclear Information System (INIS)

    Lackowski, M; Krupa, A; Jaworek, A

    2011-01-01

    The filtration of nanoparticles and submicron particles is an important problem in industry and health protection. One of the methods which can be used to solve this problem is to use nonwoven nanofibrous filters. The process of producing filtration mats of different thickness by electrospinning is presented in the paper. The experimental results on filtration properties of nanofibrous filter mat, including the efficiency of removal of cigarette smoke particles from a gas are also presented.

  9. Bleach gel: a simple agarose gel for analyzing RNA quality.

    Science.gov (United States)

    Aranda, Patrick S; LaJoie, Dollie M; Jorcyk, Cheryl L

    2012-01-01

    RNA-based applications requiring high-quality, non-degraded RNA are a foundational element of many research studies. As such, it is paramount that the integrity of experimental RNA is validated prior to cDNA synthesis or other downstream applications. In the absence of expensive equipment such as microfluidic electrophoretic devices, and as an alternative to the costly and time-consuming standard formaldehyde gel, RNA quality can be quickly analyzed by adding small amounts of commercial bleach to TAE buffer-based agarose gels prior to electrophoresis. In the presence of low concentrations of bleach, the secondary structure of RNA is denatured and potential contaminating RNases are destroyed. Because of this, the 'bleach gel' is a functional approach that addresses the need for an inexpensive and safe way to evaluate RNA integrity and will improve the ability of researchers to rapidly analyze RNA quality. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Anaphylaxis, contact urticaria, and allergic asthma caused by persulfates in hair bleaching products

    NARCIS (Netherlands)

    Hoekstra, Miriam; Schuttelaar, M.L.; Coenraads, P.J.

    2010-01-01

    Background: Persulfate salts are potent oxidizing agents in hair bleach products that accelerate the bleaching process. Ammonium and potassium persulfates may cause delayedtype and immediate skin reactions. Also allergic asthma and rhinitis have been described. Objectives: Ammonium and potassium

  11. Removal and recovery of metal ions from process and waste streams using polymer filtration

    International Nuclear Information System (INIS)

    Jarvinen, G.D.; Smith, B.F.; Robison, T.W.; Kraus, K.M.; Thompson, J.A.

    1999-01-01

    Polymer Filtration (PF) is an innovative, selective metal removal technology. Chelating, water-soluble polymers are used to selectively bind the desired metal ions and ultrafiltration is used to concentrate the polymer-metal complex producing a permeate with low levels of the targeted metal ion. When applied to the treatment of industrial metal-bearing aqueous process streams, the permeate water can often be reused within the process and the metal ions reclaimed. This technology is applicable to many types of industrial aqueous streams with widely varying chemistries. Application of PF to aqueous streams from nuclear materials processing and electroplating operations will be described

  12. Filtration Behaviour and Fouling Mechanisms of Polysaccharides

    Directory of Open Access Journals (Sweden)

    Sondus Jamal

    2014-07-01

    Full Text Available This study investigated filtration behaviors of polysaccharides solutions, both alone and in mixture with proteins, in the short-time constant flux filtration with the focus on factors affecting the transmembrane pressure (TMP increase rate, the irreversible filtration resistance, and the membrane rejection behavior. The results showed that the TMP increase rates in the short-time constant flux filtration of alginate solutions were significantly affected by the calcium addition, alginate concentration, and flux. Although the addition of calcium resulted in a decrease in the TMP increase rate, it was found that the irreversible fouling developed during the filtration increased with the calcium addition, implying that the double-sided effect of calcium on membrane filtration and that the TMP increase rate observed in the filtration does not always reflect the irreversible membrane fouling development. It was also found that for the filtration of solutions containing mixed alginate and BSA, alginate exerted a dominant effect on the TMP increase rate and the membrane exhibited a reduced rejection to both alginate and BSA molecules compared to that in the filtration of the pure alginate or BSA.

  13. Cake creep during filtration of flocculated manure

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Keiding, Kristian

    is filtered. Hence, it is not possible to scale up the experiments, and it is therefore difficult to optimize the flocculation and estimate the needed filter media area. Similar problems have been observed when sewage sludge and synthetic core-shell colloids are filtered, and it has been suggested......, and the mixing procedure affect the result, and lab-scale experiments are often used to study how these pre-treatments influence the filtration process. However, the existing mathematical filtration models are based on filtration of inorganic particles and cannot simulate the filtration data obtained when manure...

  14. Certification of Ada parts for reuse

    Science.gov (United States)

    Hansen, Gregory A.; Spaulding, S. D.; Edgar, Glenn

    1986-01-01

    One of the claims made by proponents of Ada is that Ada software is highly reusable. The fact that specifications are compiled and accessible would make reusability seem easily achievable. However, specifications give only a limited amount of information about a package; moreover, a specification cannot help determine whether a package worked, or how well it worked. This problem has led to the concept of certifying Ada parts for reuse; that is, determining the worthiness of a part as a reusable component. Issues that are critical to reuse are addressed: the characterization of part performance, design for reuse, and correct utilization of parts. Current areas of study beneficial in the development of a certification process are then addressed.

  15. Effect of bleaching on the microhardness of tooth-colored restorative materials

    Directory of Open Access Journals (Sweden)

    Abdolrahim Davari

    2013-08-01

    Full Text Available   Background and Aims: Bleaching agents not only affect the tooth structure, but also may alter the properties of restorative materials. The aim of this in vitro study was to evaluate the effect of different bleaching regimens on the microhardness of four tooth-colored restorative materials.   Materials and Methods: Eighty specimens of four restorative materials (Microhybrid resin composite (Z250 (3M, ESPE, nanohybrid composite Z350 (3M, ESPE, packable composite P60 (3M, ESPE, and resin modified glass ionomer Vitremer (3M, ESPE were fabricated and were polished after 24 h with Soflex discs (3M,ESPE. Then the specimens were divided into two groups: In office bleach group, 40 specimens (10 of each restorative material were bleached with hydrogen peroxide 37.5% for 30 min in two sessions with 7 days interval. In home bleaching group, 40 specimens were bleached with carbamid peroxide 22%, 6 h a day for 14 days. Vickers microhardness test were done before and after bleaching (baseline. Finally data were evaluated using analysis of Variance.   Results: Two bleaching regimens were significantly decreased the microhardness values. In Z250 resin composite, the microhardness values before and after bleaching were 95.30 and 92.67 kg/mm2, respectively. for office bleaching (P=0.011 and 95.38 and 92.39 kg/mm2 for home bleaching (P<0.001. In Z350 resin composite, the microhardness values before and after bleaching were 98.29 and 92.41 kg/mm2, for office bleaching (P<0.001 and 97.35 and 93.44 kg/mm2 for home bleaching (P<0.001 respectively. In P60 resin composite, the microhardness values before and after bleaching were 103.10 and 96.16 kg/mm2, respectively. for office bleaching (P=0.045 and 102.61 and 98.16 kg/mm2 for home bleaching (P=0.001. In resin modified glass ionomer (Vitremer, the microhardness values before and after bleaching were 56.79 and 49.41 kg/mm2, respectively. for office bleaching (P=0.004 and 54.17 and 46.50 kg/mm2 for home bleaching (P

  16. Treatment of leather industrial wastewater via combined advanced oxidation and membrane filtration.

    Science.gov (United States)

    Abdel-Shafy, Hussein I; El-Khateeb, Mohamed A; Mansour, Mona S M

    The liming/unhairing operation is among the important processes of the leather industry. It generates large amounts of effluent that are highly loaded with organic hazard wastes. Such effluent is considered one of the most obnoxious materials in the leather industry, causing serious environmental pollution and health risks. The effluent is characterized by high concentrations of the pollution parameters. Conventional chemical and/or biological treatment of such wastewater is inefficient to meet the required limits of standard specifications, due to the presence of resistant and toxic compounds. The present investigation deals with an effective treatment approach for the lime/unhair effluent using the Fenton reaction followed by membrane filtration. The experiment was extended to a laboratory pilot-scale in a continuous treatment study. In this study the raw wastewater was treated with the predetermined Fenton's optimum dose followed by membrane filtration. The wastewater was efficiently treated and the final effluent met the standards for unrestricted water reuse.

  17. Environmental Drivers of Variation in Bleaching Severity of Acropora Species during an Extreme Thermal Anomaly

    OpenAIRE

    Mia O. Hoogenboom; Mia O. Hoogenboom; Grace E. Frank; Grace E. Frank; Tory J. Chase; Tory J. Chase; Saskia Jurriaans; Saskia Jurriaans; Mariana Álvarez-Noriega; Mariana Álvarez-Noriega; Katie Peterson; Kay Critchell; Kathryn L. E. Berry; Kathryn L. E. Berry; Kathryn L. E. Berry

    2017-01-01

    High sea surface temperatures caused global coral bleaching during 2015–2016. During this thermal stress event, we quantified within- and among-species variability in bleaching severity for critical habitat-forming Acropora corals. The objective of this study was to understand the drivers of spatial and species-specific variation in the bleaching susceptibility of these corals, and to evaluate whether bleaching susceptibility under extreme thermal stress was consistent with that observed duri...

  18. Remote Sensing of Coral Bleaching Using Temperature and Light: Progress towards an Operational Algorithm

    OpenAIRE

    William Skirving; Susana Enríquez; John D. Hedley; Sophie Dove; C. Mark Eakin; Robert A. B. Mason; Jacqueline L. De La Cour; Gang Liu; Ove Hoegh-Guldberg; Alan E. Strong; Peter J. Mumby; Roberto Iglesias-Prieto

    2017-01-01

    The National Oceanic and Atmospheric Administration’s Coral Reef Watch program developed and operates several global satellite products to monitor bleaching-level heat stress. While these products have a proven ability to predict the onset of most mass coral bleaching events, they occasionally miss events; inaccurately predict the severity of some mass coral bleaching events; or report false alarms. These products are based solely on temperature and yet coral bleaching is known to result from...

  19. Climatological context for large-scale coral bleaching

    Science.gov (United States)

    Barton, A. D.; Casey, K. S.

    2005-12-01

    Large-scale coral bleaching was first observed in 1979 and has occurred throughout virtually all of the tropics since that time. Severe bleaching may result in the loss of live coral and in a decline of the integrity of the impacted coral reef ecosystem. Despite the extensive scientific research and increased public awareness of coral bleaching, uncertainties remain about the past and future of large-scale coral bleaching. In order to reduce these uncertainties and place large-scale coral bleaching in the longer-term climatological context, specific criteria and methods for using historical sea surface temperature (SST) data to examine coral bleaching-related thermal conditions are proposed by analyzing three, 132 year SST reconstructions: ERSST, HadISST1, and GISST2.3b. These methodologies are applied to case studies at Discovery Bay, Jamaica (77.27°W, 18.45°N), Sombrero Reef, Florida, USA (81.11°W, 24.63°N), Academy Bay, Galápagos, Ecuador (90.31°W, 0.74°S), Pearl and Hermes Reef, Northwest Hawaiian Islands, USA (175.83°W, 27.83°N), Midway Island, Northwest Hawaiian Islands, USA (177.37°W, 28.25°N), Davies Reef, Australia (147.68°E, 18.83°S), and North Male Atoll, Maldives (73.35°E, 4.70°N). The results of this study show that (1) The historical SST data provide a useful long-term record of thermal conditions in reef ecosystems, giving important insight into the thermal history of coral reefs and (2) While coral bleaching and anomalously warm SSTs have occurred over much of the world in recent decades, case studies in the Caribbean, Northwest Hawaiian Islands, and parts of other regions such as the Great Barrier Reef exhibited SST conditions and cumulative thermal stress prior to 1979 that were comparable to those conditions observed during the strong, frequent coral bleaching events since 1979. This climatological context and knowledge of past environmental conditions in reef ecosystems may foster a better understanding of how coral reefs will

  20. Reducing bleaching effects in organic nanofibers by coating

    DEFF Research Database (Denmark)

    Tavares, Luciana; Kjelstrup-Hansen, Jakob; Rubahn, Horst-Günter

    Para-hexaphenylene (p-6P) organic nanofibers emit polarized, blue light upon UV excitation with a peak wavelength of the emitted light of 425 nm [1] and a spatially anisotropic distribution of the emitted light [2]. These features could enable future (opto-)electronic applications [3], since......, we present results of systematic bleaching experiments, in which we have investigated diverse mono- and multilayer coating materials. It is found that the most promising combination results in a significant reduction of bleaching without affecting significantly the emission spectrum....

  1. Effect of nightguard vital bleaching gel on the color stability of provisional restorative materials

    Directory of Open Access Journals (Sweden)

    Salwa Omar Bajunaid

    2016-01-01

    Conclusions: Composite-based provisional material showed highest color stability when exposed to vital tooth bleaching gel, whereas methacrylate-based material was the least color stable. Polycarbonate crowns were more color stable when exposed to 15% bleaching gel as opposed to 10% bleaching gel.

  2. Cyclic filtration behavior of structured cattail fiber assembly for oils removal from wastewater.

    Science.gov (United States)

    Cao, Shengbin; Dong, Ting; Xu, Guangbiao; Wang, Fumei

    2017-06-28

    Structured cattail fiber assembly was reported as the filter for removing oils from runoff. The oil-wetted filter was recovered by rotational centrifugation and reused in the next filtration. The cyclic filtration behavior of the assembly was characterized by oil removal efficiency, oil sorption capacity, influence of packing density and number of filtration cycles. The efficiency of liquid removal and oil recovery from the centrifuged filter were also investigated. Cattail filters showed an excellent oil cyclic filtration performance which was found to have a close relationship with the inner structural characteristic of the fibers. The filters removed vegetable oil and diesel completely from runoff in the initial 40-90 min and 30-60 min in the first cycle, respectively, after which the oils broke through the filter's body and 29.4-71.4 L and 21.0-46.2 L of clean water were collected. The time of breakthrough was decreased with decreasing cattail's packing density. The wetted filters which absorbed up to 693.11 g (14.81 g/g) of vegetable oil and 497.02 g (10.62 g/g) of diesel took separately 7 min and 30 s to be recovered. Seventy-five to ninety percent of liquids were removed and 70-93% of oils were re-collected.

  3. Effectiveness of bleaching agent on composite resin discoloration

    Directory of Open Access Journals (Sweden)

    Galih Sampoerno

    2012-03-01

    Full Text Available Background: The discoloration of teeth, especially anterior teeth, is one of aesthetic problems. The use of tooth bleaching agents for discolored natural teeth is becoming increasingly popular. Many dentists, however, get many problems when they conduct bleaching process since there is much composite filling on patient’s anterior teeth. Although many research have focused on the discoloration of composite resin after bleaching process, the problem still becomes debatable. Purpose: The purpose of this study was to investigate the difference of the discoloration between hybrid composite and nano composite before and after the application of tooth bleaching agent, 38% hydrogen peroxide. Methods: Eighteen disk-shaped specimens (5 mm of each of two composite resins, hybrid and nano filler, were prepared. The each group was treated 3 times and the specimens were divided into two groups consisted of 9 specimens for each, and then immersed in black tea solutions for 72 hours. Next, after having staining and bleaching processes, the color of the specimens was measured with a optic spectrophotometer by using photo with type BPY-47 and digital microvolt. The differences of the light intensity among three measurements were then calculated. Afterwards, GLM MANOVA Repeated Measure and parametric analysis (Independent t-test and Paired t-test were then used to analyze the data. Results: After staining process, it is then known that the nano composite had more discoloration and more affected by the black tea solution than the hybrid one. Conclusion: After bleaching, the discoloration was finally removed completely from both hybride and nano filler composite resins and became brighter from the baseline color.Latar belakang: Salah satu problem estetik adalah adanya perubahan warna pada gigi anterior. Peningkatan pemakaian bahan bleaching semakin popular. Banyak dokter gigi mempunyai problem ketika mereka akan melakukan proses bleaching dan ditemukan banyak

  4. MINIMIZATION OF RETRIEVAL TIME DURING SOFTWARE REUSE ...

    African Journals Online (AJOL)

    eobe

    primary memory during pre-filtering as well as retrieval. Indexing entails computing and saving the pre-filtering features for each project as the project is being stored in the repository. The remainder of this paper is organized as follows: Section 2 briefly discusses related work. In Section 3, an overview of the software reuse ...

  5. Water brief-WDM & wastewater reuse

    International Development Research Centre (IDRC) Digital Library (Canada)

    aalfouns

    UNESCO (United Nations Education, Science and Cultural Organization), Efficient Water Demand. Management in Arid Regions, 17-21 September 2006, Sharm El-Sheikh, Egypt. Al Salem, S. and Abouzaid, H. Wastewater Reuse for Agriculture: regional health perspective. Eastern. Mediterranean Health Journal, Vol.

  6. Code Reuse and Modularity in Python

    Directory of Open Access Journals (Sweden)

    William J. Turkel

    2012-07-01

    Full Text Available Computer programs can become long, unwieldy and confusing without special mechanisms for managing complexity. This lesson will show you how to reuse parts of your code by writing Functions and break your programs into Modules, in order to keep everything concise and easier to debug. Being able to remove a single dysfunctional module can save time and effort.

  7. What is Type-Safe Code Reuse

    DEFF Research Database (Denmark)

    Schwartzbach, Michael Ignatieff; Palsberg, Jens

    1991-01-01

    Subclassing is reuse of class definitions. It is usually tied to the use of class names, thus relying on the order in which the particular classes in a program are created. This is a burden, however, both when programming and in theoretical studies. This paper presents a structural notion of subc...

  8. Constructed Wetlands for Greywater Recycle and Reuse

    Science.gov (United States)

    Concern over dwindling water supplies for urban areas as well as environmental degradation from existing urban water systems has motivated research into more resilient and sustainable water supply strategies. Greywater reuse has been suggested as a way to diversify local water su...

  9. Asset Reuse of Images from a Repository

    Science.gov (United States)

    Herman, Deirdre

    2014-01-01

    According to Markus's theory of reuse, when digital repositories are deployed to collect and distribute organizational assets, they supposedly help ensure accountability, extend information exchange, and improve productivity. Such repositories require a large investment due to the continuing costs of hardware, software, user licenses, training,…

  10. Understanding farmers' preferences for wastewater reuse ...

    African Journals Online (AJOL)

    service design, pricing strategy, and distribution channels, as well as concepts of public welfare (Louviere et al., 2000). For this study a choice modelling approach was adopted to foster understanding of farmers' preferences concerning frameworks of water reuse for irrigation. Choice modelling has gained recog- nition in ...

  11. Investing In the Reuse of Treated Wastewater

    OpenAIRE

    Darghouth, Salah; Scott, Chris; Dinar, Ariel

    2006-01-01

    Of the projected 1 billion growth in global population by 2015, 88 percent will take place in cities, nearly all of it in developing countries. Investments in urban water supply and sewerage coverage are rising. However, adequate treatment for agricultural reuse with acceptable risk mitigation for human health and the environment will require further investment. While this Investment Note ...

  12. Taxonomic, Spatial and Temporal Patterns of Bleaching in Anemones Inhabited by Anemonefishes

    KAUST Repository

    Hobbs, Jean-Paul A.

    2013-08-08

    Background:Rising sea temperatures are causing significant destruction to coral reef ecosystems due to coral mortality from thermally-induced bleaching (loss of symbiotic algae and/or their photosynthetic pigments). Although bleaching has been intensively studied in corals, little is known about the causes and consequences of bleaching in other tropical symbiotic organisms.Methodology/Principal Findings:This study used underwater visual surveys to investigate bleaching in the 10 species of anemones that host anemonefishes. Bleaching was confirmed in seven anemone species (with anecdotal reports of bleaching in the other three species) at 10 of 19 survey locations spanning the Indo-Pacific and Red Sea, indicating that anemone bleaching is taxonomically and geographically widespread. In total, bleaching was observed in 490 of the 13,896 surveyed anemones (3.5%); however, this percentage was much higher (19-100%) during five major bleaching events that were associated with periods of elevated water temperatures and coral bleaching. There was considerable spatial variation in anemone bleaching during most of these events, suggesting that certain sites and deeper waters might act as refuges. Susceptibility to bleaching varied between species, and in some species, bleaching caused reductions in size and abundance.Conclusions/Significance:Anemones are long-lived with low natural mortality, which makes them particularly vulnerable to predicted increases in severity and frequency of bleaching events. Population viability will be severely compromised if anemones and their symbionts cannot acclimate or adapt to rising sea temperatures. Anemone bleaching also has negative effects to other species, particularly those that have an obligate relationship with anemones. These effects include reductions in abundance and reproductive output of anemonefishes. Therefore, the future of these iconic and commercially valuable coral reef fishes is inextricably linked to the ability of host

  13. Biodiesel wash-water reuse using microfiltration: toward zero-discharge strategy for cleaner and economized biodiesel production

    Directory of Open Access Journals (Sweden)

    R. Jaber

    2015-03-01

    Full Text Available A simple but economically feasible refining method to treat and re-use biodiesel wash-water was developed. In detail, microfiltration (MF through depth-filtration configuration was used in different hybrid modules. Then, the treated wash-water was mixed with clean water at different ratios, re-used for biodiesel purification and water-washing efficiency was evaluated based on methyl ester purity analysis. The findings of the present study revealed that depth-filtration-based MF combined with sand filtration/activated carbon separation and 70% dilution rate with fresh water not only achieved standard-quality biodiesel product but also led to up to 15% less water consumption after two rounds of production operations. This would be translated into a considerable reduction in the total volume of fresh water used during the operation process and would also strengthen the environmental-friendly aspects of the biodiesel production process for wastewater generation was obviously cut by the same rate as well.

  14. Coral bleaching and associated mortality in Mayotte, Western Indian ...

    African Journals Online (AJOL)

    Manta tows in fringing and barrier reef areas, together with observations, were used to estimate the extent of the bleaching and associated coral mortality in Mayotte between 1 and 24 of May 2010. Three areas around the island were surveyed. The results from fringing reefs in the north coast of Mayotte showed that nearly ...

  15. Photo-bleaching of polymer discoloration caused by quinone methides

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Jan; Nešpůrek, Stanislav; Zweifel, H.; Kuthan, J.

    2002-01-01

    Roč. 78, č. 2 (2002), s. 251-255 ISSN 0141-3910 R&D Projects: GA AV ČR IAA1050901 Institutional research plan: CEZ:AV0Z4050913 Keywords : quinone methide * photo-bleaching * polymer discoloration Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.145, year: 2002

  16. Assessing Coral Community Recovery from Coral Bleaching by ...

    African Journals Online (AJOL)

    The densities of small colonies were lowest at the northern sites, and small colonies of genera of corals that suffered from high bleaching and mortality during the El Niño Southern Oscillation in 1998 were less abundant in the north. These northern reefs are relatively isolated from sources of coral larvae from reefs in the ...

  17. Bleaching and/or porcelain veneers: case reports.

    Science.gov (United States)

    Putter, H

    1992-01-01

    Four case studies are presented in which the concept that bleaching, porcelain veneer restorations, or a combination of both constitute a conservative treatment approach for discolored, malformed, malaligned, and worn dentition. These treatments can be used effectively not only for aging dentitions, but also for the very young, which makes them an attractive treatment modality.

  18. Chlorine bleaches - A significant long term source of mercury pollution

    Science.gov (United States)

    Siegel, S. M.; Eshleman, A.

    1975-01-01

    Products of industrial electrolysis of brine - NaOCl-based bleaches and NaOH - yielded 17 to 1290 ppb of Hg upon flameless atomic absorption analysis. Compared with current U.S. rejection value of 5 ppb for potable waters, the above levels seem sufficiently high to be a matter of environmental concern.

  19. Influence of local environmental conditions and bleaching histories ...

    African Journals Online (AJOL)

    Here, 10 reef-building coral samples were collected from different reefs along the Tanzanian coast with different micro-environments and bleaching histories. The ITS-2 region of ribosomal DNA was employed in the characterisation of Symbiodinium harboured by reef-building corals. DGGE fingerprints and DNA sequences ...

  20. Value-added products from spent bleaching earth

    International Nuclear Information System (INIS)

    Loh Soh Kheang; Muzammil Ngatiman; James, Stephen

    2010-01-01

    Full text: Bleaching earth is used in the bleaching process of physical refining of palm oil to remove color, phospholipids, residue gums, oxidized products and any trace metals from the oil. These colored pigments are trapped and absorbed in the bleaching earth, thus transforming the originally whitish earth to dark grey and is, from then, named spent bleaching earth (SBE). SBE is considered as an industrial by-product as there is hardly any practical application for it. Large quantity of SBE is commonly disposed of in landfills, which poses potential hazards to environment. New economical ways in utilizing it is sought to eliminate the problem arises from its disposal. This paper presents a study on the possibility of developing a soil conditioner using enhanced SBE as the base material. The study found that there are certain attributes observed in the enhanced SBE that could be of advantages for SBE to become a good soil conditioner. The enhanced SBE contains organic matters and about 18-20 % of residue oil which exhibits good water holding capacity in slow release of water, and enriched nutrient content for plant nutrient uptake. (author)

  1. Project Overview: A Reef Manager's Guide to Coral Bleaching ...

    Science.gov (United States)

    The purpose of this report is to provide the latest scientific knowledge and discuss available management options to assist local and regional managers in responding effectively to mass coral bleaching events. Background A Reef Manager’s Guide to Coral Bleaching is the result of a collaborative effort by over 50 scientists and managers to: (1) share the best available scientific information on climate-related coral bleaching; and (2) compile a tool kit of currently available strategies for adaptive management of coral reefs in a changing climate. The result is a compendium of current information, tools, and practical suggestions to aid managers in their efforts to protect reefs in a way that maximizes reef resilience in the face of continuing climate change. The Guide is a joint publication of the National Oceanic and Atmospheric Administration, the Great Barrier Reef Marine Park Authority, and The World Conservation Union, with author contributions from a variety of international partners from government agencies, non-governmental organizations, and academic institutions. EPA’s Office of Research and Development was a major contributor to the Guide through authorship and participation in the final review and editing process for the entire report. A Reef Manager’s Guide to Coral Bleaching is the result of a collaborative effort by over 50 scientists and managers to: (1) share the best available scientific information on climate-related coral blea

  2. Guest–host interactions in the alkaline bleaching of ...

    Indian Academy of Sciences (India)

    Administrator

    534 ported that in fading of triphenylmethane dye addi- tion of alcohol retards the rate. There is similarity between CD catalysed and micellar catalysed reac- tion of bleaching of the triphenylmethane dyes for water reaction. For RA, CD decelerates the rate of both water and hydroxide ion reaction (table 4). This is contrary to.

  3. Bleached and unbleached MFC nanobarriers: properties and hydrophobisation with hexamethyldisilazane

    Energy Technology Data Exchange (ETDEWEB)

    Chinga-Carrasco, Gary, E-mail: gary.chinga.carrasco@pfi.no [Paper and Fibre Research Institute (PFI) (Norway); Kuznetsova, Nina; Garaeva, Milyausha [Kazan National Research Technological University (KNRTU) (Russian Federation); Leirset, Ingebjorg [Paper and Fibre Research Institute (PFI) (Norway); Galiullina, Guzaliya; Kostochko, Anatoly [Kazan National Research Technological University (KNRTU) (Russian Federation); Syverud, Kristin [Paper and Fibre Research Institute (PFI) (Norway)

    2012-12-15

    This study explores the production and surface modification of microfibrillated cellulose (MFC), based on unbleached and bleached Pinus radiata pulp fibres. Unbleached Pinus radiata pulp fibres tend to fibrillate easier by homogenisation without pre-treatment, compared to the corresponding bleached MFC. The resulting unbleached MFC films have higher barrier against oxygen, lower water wettability and higher tensile strength than the corresponding bleached MFC qualities. In addition, it is demonstrated that carboxymethylation can also be applied for production of highly fibrillated unbleached MFC. The nanofibril size distribution of the carboxymethylated MFC is narrow with diameters less than 20 nm, as quantified on high-resolution field-emission scanning electron microscopy images. The carboxymetylation had a larger fibrillation effect on the bleached pulp fibres than on the unbleached one. Importantly, the suitability of hexamethyldisilazane (HMDS) as a new alternative for rendering MFC films hydrophobic was demonstrated. The HMDS-modified films made of carboxymethylated MFC had oxygen permeability levels better than 0.06 mL mm m{sup -2} day{sup -1} atm{sup -1}, which is a good property for some packaging applications.

  4. Bleached and unbleached MFC nanobarriers: properties and hydrophobisation with hexamethyldisilazane

    Science.gov (United States)

    Chinga-Carrasco, Gary; Kuznetsova, Nina; Garaeva, Milyausha; Leirset, Ingebjørg; Galiullina, Guzaliya; Kostochko, Anatoly; Syverud, Kristin

    2012-12-01

    This study explores the production and surface modification of microfibrillated cellulose (MFC), based on unbleached and bleached Pinus radiata pulp fibres. Unbleached Pinus radiata pulp fibres tend to fibrillate easier by homogenisation without pre-treatment, compared to the corresponding bleached MFC. The resulting unbleached MFC films have higher barrier against oxygen, lower water wettability and higher tensile strength than the corresponding bleached MFC qualities. In addition, it is demonstrated that carboxymethylation can also be applied for production of highly fibrillated unbleached MFC. The nanofibril size distribution of the carboxymethylated MFC is narrow with diameters less than 20 nm, as quantified on high-resolution field-emission scanning electron microscopy images. The carboxymetylation had a larger fibrillation effect on the bleached pulp fibres than on the unbleached one. Importantly, the suitability of hexamethyldisilazane (HMDS) as a new alternative for rendering MFC films hydrophobic was demonstrated. The HMDS-modified films made of carboxymethylated MFC had oxygen permeability levels better than 0.06 mL mm m-2 day-1 atm-1, which is a good property for some packaging applications.

  5. Coral Bleaching and Associated Mortality at Mayotte, Western Indian ...

    African Journals Online (AJOL)

    the 1998 ENSO event. Acknowledgement–We thank Benjamin. Esperance, la Direction de l'Agriculture et de la Forêt (DAF), and Léonard Durasnel and Said Mohammed, Conseil General de. Mayotte, for supporting this study. Table 1. Genera commonly bleached at Mayotte in May 2010, listed in the order of the degree and.

  6. POM-assisted electrochemical delignification and bleaching of chemical pulp

    Science.gov (United States)

    Helene Laroche; Mohini Sain; Carl Houtman; Claude Daneault

    2001-01-01

    A polyoxometalate-catalyzed electrochemical process has shown good selectivity in delignifying pulp. This breakthrough in redox catalysis shows promise for the development of a new environmentally benign technology for pulp bleaching. The electrochemical process, applied with a mildly alkaline electrolyte solution containing trace amounts of a vanadium-based...

  7. Bleach Solution Requirement for Hatching of Daphnia magna Resting Eggs

    Directory of Open Access Journals (Sweden)

    Catur Retnaningdyah

    2016-11-01

    Full Text Available Daphnia (water fleas belong to the zooplankton group called Cladocerans have sexual reproduction when conditions less favorable that produce diapausing eggs are enclosed in the ephippium. Hatching ephippial eggs in the laboratory is important in ecological, toxicology, genetical, and evolutionary studies. This study aims to improve the current methods of egg hatching from ephippium. Each of 50 ephippium were treated together by placing them in a glass jar and adding 50 mL bleach solution (sodium hypochlorite. Concentrations of sodium hypochlorite used in this experiment were 0%, 0.5%, 1%, 2%, 4% and 8%. These concentration treatments were crossed with the following exposure times (1, 2, 4, 8, 16, and 32 minutes. Culturing was done in 80 mL of artificial Daphnia medium, incubated in constant light and temperatures 20°C for 25 days. There were two repetitions in this experiment that were run at the same time. Result of this experiment showed that pretreatment with 0.5-8% bleach solution significantly increases the yield of total hatch rate of Daphnia magna resting eggs by about 21% over unbleached control. However, there was no significant difference among the bleach treatments. Concentration of bleach solution 0.5%, 1% and 4% significantly accelerated the time period until the first hatching (first day hatching. Difference of exposure time (1 - 32 minutes at each concentration treatments were not influence the yield of total hatch and the time period until first hatching.

  8. Natural and recombinant fungal laccases for paper pulp bleaching

    NARCIS (Netherlands)

    Sigoillot, C.; Record, E.; Belle, V.; Robert, J.L.; Levasseur, A.; Punt, P.J.; Hondel, C.A.M.J.J. van den; Fournel, A.; Sigoillot, J.C.; Asther, M.

    2004-01-01

    Three laccases, a natural form and two recombinant forms obtained from two different expression hosts, were characterized and compared for paper pulp bleaching. Laccase from Pycnoporus cinnabarinus, a well known lignolytic fungus, was selected as a reference for this study. The corresponding

  9. Spent Bleaching Earth as a Pozzolanic Material | Muthengia ...

    African Journals Online (AJOL)

    This paper proposes a cementing material from spent bleaching earth (SBE). SBE consists mainly of residual oil and ... The setting time of a workable paste of the ashed SBE-lime material was well within the Kenya standard 02 1263 requirements for Portland pozzolana cements. Key words: Cement, pozzolana, Spent ...

  10. Symbiont Dependent Thermal Bleaching Susceptiblity in Two Reef ...

    African Journals Online (AJOL)

    user1

    Differential bleaching susceptibility among scleractinian corals has been documented both in the field in Okinawa, Japan (Loya et al. 2001), on the Great Barrier Reef, Australia (Marshall &. Baird, 2000; Baird & Marshall, 2002), and in the Indian Ocean (Spencer et al. 2000) and under experimental trials (Fitt & Warner, 1995; ...

  11. Assessing dentin color changes from nightguard vital bleaching.

    Science.gov (United States)

    McCaslin, A J; Haywood, V B; Potter, B J; Dickinson, G L; Russell, C M

    1999-10-01

    At-home bleaching with 10 percent carbamide peroxide in a custom-fitted tray has been reported to change the color of dentin. The purpose of this study was to validate the color change of dentin and to determine whether the color change was uniform or occurred from the outside (the dentinoenamel junction) to the inside (the pulpal wall). The authors sectioned 10 extracted human teeth incisogingivally through the midfacial long axis, and sealed their cut surface against glass microscope slides. Identifying marks were placed on the glass over the tooth sections to serve as a color control and in the dentinal areas closest to the dentinoenamel junction and the pulpal wall. Teeth were bleached for 10 days with 10 percent carbamide peroxide. Photographs were taken from the glass-covered side of the teeth, digitized and converted to gray-scale levels (consisting of 256 shades of gray ranging from black to white). Marked areas were measured with a National Institutes of Health Image software program and analyzed statistically for changes in lightness between the control marks and the inner and outer dentinal marks over time. Paired t-tests and analysis of variance indicated a significant increase in lightness (P = .01) for the inner and outer dentinal areas during bleaching compared with the control areas. No significant differences were found in the rate of change for the inner and outer dentinal areas (P = .89). The increase in lightness confirms that a significant color change occurred in the dentin during bleaching with 10 percent carbamide peroxide. This change occurred throughout the dentin at a uniform rate, rather than from the outside inward. The results of this study show that at-home bleaching with 10 percent carbamide peroxide can change the color of dentin, which is important to treat intrinsic stains from tetracycline treatment, trauma and aging or inherited discolorations. The bleaching material easily penetrates the tooth to change the dentin color at the

  12. Bahan pemutih gigi dengan sertifikat ADA/ISO (Tooth bleaching material with ADA/ISO certificate

    Directory of Open Access Journals (Sweden)

    Asti Meizarini

    2005-06-01

    Full Text Available Bleaching of teeth for cosmetic reasons is a popular aspect of cosmetic dentistry because patients realize the aesthetical benefits of these products. The dentist as a clinician's practitioner must be knowledgeable of the products and their application techniques. Bleaching materials which are safe and effective are the ADA accepted or manufactured by those which have already haved ISO certificate. Dentist must have enough knowledge about in-office bleaching prescribed for home-use bleaching including their contra indication and side effects, to advise the patients and provide effective bleaching services.

  13. Large-scale bleaching of corals on the Great Barrier Reef.

    Science.gov (United States)

    Hughes, T P; Kerry, J T; Simpson, T

    2018-02-01

    In 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching. In the southern hemisphere summer of March-April 2016, we used aerial surveys to measure the level of bleaching on 1,156 individual reefs throughout the 2,300 km length of the Great Barrier Reef, the world's largest coral reef system. The accuracy of the aerial scores was ground-truthed with detailed underwater surveys of bleaching at 260 sites (104 reefs), allowing us to compare aerial and underwater bleaching data with satellite-derived temperatures and with associated model predictions of bleaching. The severity of bleaching on individual reefs in 2016 was tightly correlated with the level of local heat exposure: the southernmost region of the Great Barrier Reef escaped with only minor bleaching because summer temperatures there were close to average. Gradients in nutrients and turbidity from inshore to offshore across the Great Barrier Reef had minimal effect on the severity of bleaching. Similarly, bleaching was equally severe on reefs that are open or closed to fishing, once the level of satellite-derived heat exposure was accounted for. The level of post-bleaching mortality, measured underwater after 7-8 months, was tightly correlated with the aerial scores measured at the peak of bleaching. Similarly, reefs with a high aerial bleaching score also experienced major shifts in species composition due to extensive mortality of heat-sensitive species. Reefs with low bleaching scores did not change in composition, and some showed minor increases in coral cover. Two earlier mass bleaching events occurred on the Great Barrier Reef in 1998 and 2002, that were less severe than 2016. In 2016, reefs had no bleaching, compared to 42% in 2002 and 44% in 1998. Conversely, the proportion of reefs that were severely bleached (>60% of corals affected) was four times higher in 2016. The geographic footprint of each of the three events is distinctive, and matches satellite-derived sea

  14. Effect of coffee and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching.

    Science.gov (United States)

    Pirolo, Rodrigo; Mondelli, Rafael Francisco Lia; Correr, Gisele Maria; Gonzaga, Carla Castiglia; Furuse, Adilson Yoshio

    2014-01-01

    There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching. To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching. Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max) and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO) before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD) at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E) and lightness (∆L) variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (ppigmented with coffee presented ∆E values below 3.3 units for all evaluation times. The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching.

  15. Effect of coffe and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching

    Science.gov (United States)

    PIROLO, Rodrigo; MONDELLI, Rafael Francisco Lia; CORRER, Gisele Maria; GONZAGA, Carla Castiglia; FURUSE, Adilson Yoshio

    2014-01-01

    There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching. Objective: To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching. Materials and methods: Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max) and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO) before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD) at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E) and lightness (∆L) variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (pteeth stained with a CBSD at 10 min and 1 h (4.12 and 4.16, respectively). Teeth pigmented with coffee presented ∆E values below 3.3 units for all evaluation times. Conclusion: The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching. PMID:25075672

  16. Tropical cyclone cooling combats region-wide coral bleaching.

    Science.gov (United States)

    Carrigan, Adam D; Puotinen, Marji

    2014-05-01

    Coral bleaching has become more frequent and widespread as a result of rising sea surface temperature (SST). During a regional scale SST anomaly, reef exposure to thermal stress is patchy in part due to physical factors that reduce SST to provide thermal refuge. Tropical cyclones (TCs - hurricanes, typhoons) can induce temperature drops at spatial scales comparable to that of the SST anomaly itself. Such cyclone cooling can mitigate bleaching across broad areas when well-timed and appropriately located, yet the spatial and temporal prevalence of this phenomenon has not been quantified. Here, satellite SST and historical TC data are used to reconstruct cool wakes (n=46) across the Caribbean during two active TC seasons (2005 and 2010) where high thermal stress was widespread. Upon comparison of these datasets with thermal stress data from Coral Reef Watch and published accounts of bleaching, it is evident that TC cooling reduced thermal stress at a region-wide scale. The results show that during a mass bleaching event, TC cooling reduced thermal stress below critical levels to potentially mitigate bleaching at some reefs, and interrupted natural warming cycles to slow the build-up of thermal stress at others. Furthermore, reconstructed TC wave damage zones suggest that it was rare for more reef area to be damaged by waves than was cooled (only 12% of TCs). Extending the time series back to 1985 (n = 314), we estimate that for the recent period of enhanced TC activity (1995-2010), the annual probability that cooling and thermal stress co-occur is as high as 31% at some reefs. Quantifying such probabilities across the other tropical regions where both coral reefs and TCs exist is vital for improving our understanding of how reef exposure to rising SSTs may vary, and contributes to a basis for targeting reef conservation. © 2014 John Wiley & Sons Ltd.

  17. Surface discoloration of composite resins: Effects of staining and bleaching

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2012-01-01

    Background: The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet•X HD, Clearfil AP-X, Gradia Direct) and five nanohybrid composite resins (Ceram•X, GC Kalore, G-aenial, Grandio, GrandioSO), after staining and bleaching procedures. Materials and Methods: The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany) into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness) to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h), for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco). The color of specimens was measured with a spectrophotometer according to the CIE L*a*b* system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DEab*) between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA). Results: All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Conclusions: Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested. PMID:23559921

  18. Surface discoloration of composite resins: Effects of staining and bleaching

    Directory of Open Access Journals (Sweden)

    Claudio Poggio

    2012-01-01

    Full Text Available Background: The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet·X HD, Clearfil AP-X, Gradia Direct and five nanohybrid composite resins (Ceram·X, GC Kalore, G-aenial, Grandio, GrandioSO, after staining and bleaching procedures. Materials and Methods: The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h, for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco. The color of specimens was measured with a spectrophotometer according to the CIE LFNx01aFNx01bFNx01 system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DE abFNx01 between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA. Results: All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Conclusions: Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested.

  19. Surface discoloration of composite resins: Effects of staining and bleaching.

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2012-09-01

    The purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (Esthet•X HD, Clearfil AP-X, Gradia Direct) and five nanohybrid composite resins (Ceram•X, GC Kalore, G-aenial, Grandio, GrandioSO), after staining and bleaching procedures. The composite resins were polymerized with a curing light (Celalux II, Voco, Cuxhaven, Germany) into 160 silicon molds (6,4 mm in diameter and 2 mm in thickness) to obtain identical specimens. Twenty samples for each composite resin were prepared. The specimens were polished using an automated polishing machine with the sequence of 600-, 800-, 1000-grit abrasive paper under water irrigation. The specimens were immersed in tea and distilled water: the specimens were dipped for 20 min, once a day (every 24 h), for 14 days into the drinks. The specimens were then bleached with carbamide peroxide at 17% (Perfect Bleach-Voco). The color of specimens was measured with a spectrophotometer according to the CIE L(*)a(*)b(*) system after light-polymerization of composite resin specimens, after 7 days, after 14 days, and after bleaching. The color difference h index (DEab(*)) between each measurement was calculated. Statistical analysis was made using analysis of variance (ANOVA). All specimens showed a significant increase in staining with a similar trend and no significant differences between microhybrid and nanohybrid composite resins. After whitening procedures, materials tested showed both significant and unsignificant differences of the h index. Microhybrid and nanohybrid composite resins had similar in vitro surface discoloration in tea. After bleaching, discoloration was removed from some composite resins tested.

  20. Depletion Rate of Hydrogen Peroxide from Sodium Perborate Bleaching Agent.

    Science.gov (United States)

    Tran, Liliann; Orth, Rebecca; Parashos, Peter; Tao, Ying; Tee, Calvin W J; Thomas, Vineet Thenalil; Towers, Georgina; Truong, Diem Thuy; Vinen, Cynthia; Reynolds, Eric C

    2017-03-01

    Internal bleaching of discolored teeth uses sodium perborate reacting with water to form the active agent, hydrogen peroxide (H 2 O 2 ). Sodium perborate is replaced at varying time intervals depending on clinician preference and until esthetically acceptable results are achieved, but this is done without scientific basis. This study measured the depletion rate of hydrogen peroxide from sodium perborate as a bleaching agent. Two sodium perborate bleaching products (Odontobleach [Australian Dental Manufacturing, Kenmore Hills, Queensland, Australia] and Endosure Perborate Micro [Dentalife, Ringwood, Victoria, Australia]) and distilled deionized water mixtures at ratios of 25 μg/mL, 50 μg/mL, and 100 μg/mL were placed into sealed microtubes and incubated at 37°C. H 2 O 2 concentrations were measured at 23 time points over 4 weeks. Quantification of H 2 O 2 concentrations was obtained using a ferrothiocyanate oxidation reduction reaction followed by spectrophotometry readings. The H 2 O 2 concentration rapidly peaked within 27 hours and reached a plateau by about 3 days (75 hours). Low levels of H 2 O 2 were evident beyond 3 days and for at least 28 days. No significant differences were found between the 2 sodium perborate products. There was also no significant difference in the depletion rate between the different ratios. Based on the chemistry of H 2 O 2 depletion, the minimum replacement interval for the bleaching agent is 3 days. Frequent replacements of the perborate clinically may be unnecessary because of the continued presence of low H 2 O 2 levels for at least 28 days. Although these data cannot be extrapolated to the clinical situation, they set a baseline for further studies to address the many clinical variables influencing internal bleaching. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  1. Savannah River Site Surplus Facilities Available for Reuse

    International Nuclear Information System (INIS)

    Clarke, R.M.; Owens, M.B.; Lentz, D.W.

    1995-01-01

    The purpose of this document is to provide a current, centralized list of Savannah River Site facilities, which are surplus and available for reuse. These surplus facilities may be made available for other DOE site missions, commercial economic development reuse, or other governmental reuse. SRS procedures also require that before new construction can be approved, available surplus facilities are screened for possible reuse in lieu of the proposed new construction

  2. Beneficial reuse `96: The fourth annual conference on the recycle and reuse of radioactive scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    From October 22-24, 1996 the University of Tennessee`s Energy, Environment and Resources Center and the Oak Ridge National Laboratory`s Center for Risk Management cosponsored Beneficial Reuse `96: The Fourth Annual Conference on the Recycle and Reuse of Radioactive Materials. Along with the traditional focus on radioactive scrap metals, this year`s conference included a wide range of topics pertaining to naturally occurring radioactive materials (NORM), and contaminated concrete reuse applications. As with previous Beneficial Reuse conferences, the primary goal of this year`s conference was to bring together stakeholder representatives for presentations, panel sessions and workshops on significant waste minimization issues surrounding the recycle and reuse of contaminated metals and other materials. A wide range of industry, government and public stakeholder groups participated in this year`s conference. An international presence from Canada, Germany and Korea helped to make Beneficial Reuse `96 a well-rounded affair. Selected papers have been processed separately for inclusion in the Energy Science and Technology Database.

  3. Tooth bleaching induces changes in the vascular permeability of rat incisor pulps.

    Science.gov (United States)

    Ferreira, Vanessa Guarino; Nabeshima, Cleber Keiti; Marques, Márcia Martins; Paris, Adriana Fraga Costa Samos; Gioso, Marco Antônio; dos Reis, Rodrigo Sant'anna Aguiar; Machado, Manoel Eduardo de Lima

    2013-10-01

    To evaluate the inflammatory response in dental pulps of rat incisors subjected to tooth bleaching protocols with different HP concentrations and application times. 42 incisors from Wistar rats were submitted to tooth bleaching using concentrations of 25% or 35% HP for treatment times of 15, 30 or 45 minutes. Four non-bleached teeth were used as controls. The animals received an intravenous injection of India ink immediately after the bleaching procedure and were sacrificed 1 hour later. Six bleached teeth from each group and three controls were made transparent, and one sample from each group was processed for histological analysis. The data were statistically analyzed using Kruskal Wallis and Dunn's tests (P ink content was significantly higher in the samples that were bleached with 35% HP for 30 minutes and with both HP concentrations (25 and 35%) for 45 minutes than in the controls. For the samples bleached with the same HP concentration, the ink content was higher in samples that were bleached for 45 minutes. These results indicate that HP tooth bleaching can induce an increase in vascular permeability in rat incisors. Importantly, this increase is more dependent on the length of the bleaching procedure than on the concentration of the bleaching agent.

  4. In-office bleaching effects on the pulp flow and tooth sensitivity – case series

    Directory of Open Access Journals (Sweden)

    Andrés Felipe CARTAGENA

    2015-01-01

    Full Text Available Laser Doppler flowmetry (LDF is a noninvasive method capable of evaluating variations in pulp blood flow (PBF and pulp vitality. This method has thus far not been used to assess changes in blood flow after in-office bleaching. The aim of this case series report was to measure changes in PBF by LDF in the upper central incisor of three patients submitted to in-office bleaching. The buccal surfaces of the upper arch were bleached with a single session of 35% hydrogen peroxide gel with three 15-min applications. The color was recorded using a value-oriented Vita shade guide before in-office bleaching and one week after the procedure. The tooth sensitivity (TS in a verbal scale was reported, and PBF was assessed by LDF before, immediately, and one week after the bleaching session. The lower arch was submitted to dental bleaching but not used for data assessment. A whitening degree of 3 to 4 shade guide units was detected. All participants experienced moderate to considerable TS after the procedure. The PBF readings reduced 20% to 40% immediately after bleaching. One week post-bleaching, TS and PBF were shown to be equal to baseline values. A reversible decrease of PBF was detected immediately after bleaching, which recovered to the baseline values or showed a slight increase sooner than one week post-bleaching. The LDF method allows detection of pulp blood changes in teeth submitted to in-office bleaching, but further studies are still required.

  5. Effect of the Purple Corn Beverage “Chicha Morada” in Composite Resin during Dental Bleaching

    Directory of Open Access Journals (Sweden)

    Eric Dario Acuña

    2016-01-01

    Full Text Available During dental bleaching the staining potential of the surface would increase. This study aims to evaluate the staining susceptibility of one bleached composite resin after the exposure to three different beverages: Peruvian purple corn based beverage (chicha morada, green tea, and distilled water. Thirty disk-shaped specimens of one nanofill composite resin were prepared. The specimens were then divided into six groups (n=5: purple corn (P, purple corn + bleaching (PB, green tea (T, green tea + bleaching (TB, distilled water (W, and distilled water + bleaching (WB. In groups that received bleaching, two sessions of bleaching with 35% hydrogen peroxide were done. Following bleaching, specimens were exposed to each liquid thirty minutes daily. Color was measured with a digital spectrophotometer. For statistical analysis, color measurement differences between the obtained results were used: during bleaching, after bleaching, and during + after bleaching. Two-way ANOVA was used to compare the color changes in the resins of all groups (p3.3.

  6. Effect of in-office bleaching agents on physical properties of dental composite resins.

    Science.gov (United States)

    Mourouzis, Petros; Koulaouzidou, Elisabeth A; Helvatjoglu-Antoniades, Maria

    2013-04-01

    The physical properties of dental restorative materials have a crucial effect on the longevity of restorations and moreover on the esthetic demands of patients, but they may be compromised by bleaching treatments. The purpose of this study was to evaluate the effects of in-office bleaching agents on the physical properties of three composite resin restorative materials. The bleaching agents used were hydrogen peroxide and carbamide peroxide at high concentrations. Specimens of each material were prepared, cured, and polished. Measurements of color difference, microhardness, and surface roughness were recorded before and after bleaching and data were examined statistically by analysis of variance (ANOVA) and Tukey HSD post-hoc test at P composite resin altered after the bleaching procedure (P composite resins tested (P > .05). The silorane-based composite resin tested showed some color alteration after bleaching procedures. The bleaching procedure did not alter the microhardness and the surface roughness of all composite resins tested.

  7. Response of sponges with autotrophic endosymbionts during the coral-bleaching episode in Puerto Rico

    Science.gov (United States)

    Vicente, V. P.

    1990-04-01

    An updated list of sponges with algal endosymbionts including new records for Puerto Rico and the Caribbean, indicates that thirty-five species of common Caribbean sponges possess photosynthetic endosymbionts. Of these, 23 (67.6%) species in seven orders, were found with unicellular chroococcoid cyanobacteria ( Aphanocapsa-like) and 5 (14.7%) hadromerid species were found with zooxanthellae. Sponges with other algae as symbionts occur less frequently (≦6%). Thirty-one common sponge species were inspected for bleaching during coral-bleaching months (July-September 1987; January 1988) in Puerto Rico. Anthosigmella varians, Xestospongia muta and Petrosia pellasarca bleached partially, but only few individuals within any given population became bleached and the bleaching of sponges was very localized. Adaptations between cyanobacterial symbionts and sponges, acquired during the long evolutionary history of these two taxa may explain the paucity of bleached sponges when compared to the high incidence of bleached corals reported.

  8. Development of waste water reuse water system for power plants

    Energy Technology Data Exchange (ETDEWEB)

    Park, K.K.; Kim, D.H.; Weon, D.Y.; Yoon, S.W.; Song, H.R. [Korea Electric Power Research Institute, Taejeon (Korea, Republic of)

    1997-12-31

    1. Status of waste water discharge at power plants 2. Present status of waste water reuse at power plants 3. Scheme of waste water reuse at power plants 4. Standardization of optimum system for waste water reuse at power plants 5. Establishment of low cost zero discharge system for waste water 6. Waste water treatment technology of chemical cleaning. (author). 132 figs., 72 tabs.

  9. Conceptual Match as a Determinant of Reference Reuse in Dialogue

    Science.gov (United States)

    Knutsen, Dominique; Le Bigot, Ludovic

    2017-01-01

    As speakers interact, they add references to their common ground, which they can then reuse to facilitate listener comprehension. However, all references are not equally likely to be reused. The purpose of this study was to shed light on how the speakers' conceptualizations of the referents under discussion affect reuse (along with a generation…

  10. Minimization of Retrieval Time During Software Reuse | Salami ...

    African Journals Online (AJOL)

    Software reuse refers to the development of software using existing software. Reuse of software can help reduce software development time and overall cost. Retrieval of relevant software from the repository during software reuse can be time consuming if the repository contains many projects, and/or the retrieval process is ...

  11. Filtrating forms of soil bacteria

    Science.gov (United States)

    Van'kova, A. A.; Ivanov, P. I.; Emtsev, V. T.

    2013-03-01

    Filtrating (ultramicroscopic) forms (FF) of bacteria were studied in a soddy-podzolic soil and the root zone of alfalfa plants as part of populations of the most widespread physiological groups of soil bacteria. FF were obtained by filtering soil solutions through membrane filters with a pore diameter of 0.22 μm. It was established that the greater part of the bacteria in the soil and in the root zone of the plants has an ultramicroscopic size: the average diameter of the cells is 0.3 μm, and their length is 0.6 μm, which is significantly less than the cell size of banal bacteria. The number of FF varies within a wide range depending on the physicochemical conditions of the habitat. The FF number's dynamics in the soil is of a seasonal nature; i.e., the number of bacteria found increases in the summer and fall and decreases in the winter-spring period. In the rhizosphere of the alfalfa, over the vegetation period, the number of FF and their fraction in the total mass of the bacteria increase. A reverse tendency is observed in the rhizoplane. The morphological particularities (identified by an electron microscopy) and the nature of the FF indicate their physiological activity.

  12. Environmental Drivers of Variation in Bleaching Severity of Acropora Species during an Extreme Thermal Anomaly

    Directory of Open Access Journals (Sweden)

    Mia O. Hoogenboom

    2017-11-01

    Full Text Available High sea surface temperatures caused global coral bleaching during 2015–2016. During this thermal stress event, we quantified within- and among-species variability in bleaching severity for critical habitat-forming Acropora corals. The objective of this study was to understand the drivers of spatial and species-specific variation in the bleaching susceptibility of these corals, and to evaluate whether bleaching susceptibility under extreme thermal stress was consistent with that observed during less severe bleaching events. We surveyed and mapped Acropora corals at 10 sites (N = 596 around the Lizard Island group on the northern Great Barrier Reef. For each colony, bleaching severity was quantified using a new image analysis technique, and we assessed whether small-scale environmental variables (depth, microhabitat, competition intensity and species traits (colony morphology, colony size, known symbiont clade association explained variation in bleaching. Results showed that during severe thermal stress, bleaching of branching corals was linked to microhabitat features, and was more severe at reef edge compared with lagoonal sites. Bleaching severity worsened over a very short time-frame (~1 week, but did not differ systematically with water depth, competition intensity, or colony size. At our study location, within- and among-species variation in bleaching severity was relatively low compared to the level of variation reported in the literature. More broadly, our results indicate that variability in bleaching susceptibility during extreme thermal stress is not consistent with that observed during previous bleaching events that have ranged in severity among globally dispersed sites, with fewer species escaping bleaching during severe thermal stress. In addition, shaded microhabitats can provide a refuge from bleaching which provides further evidence of the importance of topographic complexity for maintaining the biodiversity and ecosystem

  13. Calculating Reuse Distance from Source Code

    Energy Technology Data Exchange (ETDEWEB)

    Narayanan, Sri Hari Krishna; Hovland, Paul

    2016-01-26

    The efficient use of a system is of paramount importance in high-performance computing. Applications need to be engineered for future systems even before the architecture of such a system is clearly known. Static performance analysis that generates performance bounds is one way to approach the task of understanding application behavior. Performance bounds provide an upper limit on the performance of an application on a given architecture. Predicting cache hierarchy behavior and accesses to main memory is a requirement for accurate performance bounds. This work presents our static reuse distance algorithm to generate reuse distance histograms. We then use these histograms to predict cache miss rates. Experimental results for kernels studied show that the approach is accurate.

  14. Coral diseases and bleaching on Colombian Caribbean coral reefs

    Directory of Open Access Journals (Sweden)

    Raúl Navas-Camacho

    2010-05-01

    Full Text Available Since 1998 the National Monitoring System for the Coral Reefs of Colombia (SIMAC has monitored the occurrence of coral bleaching and diseases in some Colombian coral reefs (permanent stations at San Andres Island, Rosario Islands, Tayrona, San Bernardo Islands and Urabá. The main purpose is to evaluate their health status and to understand the factors that have been contributing to their decline. To estimate these occurrences, annual surveys in 126 permanent belt transects (10x2m with different depth intervals (3-6 meters, 9-12 meters and 15-18 meters are performed at all reef sites. Data from the 1998-2004 period, revealed that San Andrés Island had many colonies with diseases (38.9 colonies/m2, and Urabá had high numbers with bleaching (54.4 colonies/m2. Of the seven reported coral diseases studied, Dark Spots Disease (DSD, and White Plague Disease (WPD were noteworthy because they occurred in all Caribbean monitored sites, and because of their high interannual infection incidence. Thirty five species of scleractinian corals were affected by at least one disease and a high incidence of coral diseases on the main reef builders is documented. Bleaching was present in 34 species. During the whole monitoring period, Agaricia agaricites and Siderastrea siderea were the species most severely affected by DSD and bleaching, respectively. Diseases on species such as Agaricia fragilis, A.grahamae, A. humilis, Diploria clivosa, Eusmilia fastigiata, Millepora complanata, and Mycetophyllia aliciae are recorded for first time in Colombia. We present bleaching and disease incidences, kinds of diseases, coral species affected, reef localities studied, depth intervals of surveys, and temporal (years variation for each geographic area. This variation makes difficult to clearly determine defined patterns or general trends for monitored reefs. This is the first long-term study of coral diseases and bleaching in the Southwestern Caribbean, and one of the few

  15. Direct Reuse of Rare Earth Permanent Magnets—Coating Integrity

    DEFF Research Database (Denmark)

    Høgberg, Stig; Holbøll, Joachim; Mijatovic, Nenad

    2017-01-01

    Rare earth permanent magnets can be reused directly as an alternative to traditional recycling methods, in which scrapped magnets are reprocessed into new magnets by undergoing many of the original energy-intensive and expensive production processes. Direct reuse entails using segmented magnet...... assemblies built by several small standard-sized magnets that can be reused directly in a number of different applications. A central part of the direct reuse strategy is to separate and demagnetize magnets by heating them to the Curie temperature. We investigated the validity of direct reuse as a rare earth...

  16. Highly efficient and recyclable depth filtrating system using structured kapok filters for oil removal and recovery from wastewater.

    Science.gov (United States)

    Dong, Ting; Cao, Shengbin; Xu, Guangbiao

    2017-01-05

    A depth filtrating system with rotatable and taper-shaped filter column was reported to highly remove and recover oil from wastewater. In the work, structure filters made of kapok fibers were prepared by air-laying-bonding method. The oil removed from wastewater was then recovered from the oil-loaded filter by rotating the filter column, and the resulted filter was reused. The filtrating system demonstrated extremely high oil/water separation in which oil was completely retained by the filter at the first 20-100min while water passed through the filter's body with a flow rate of 560mL/min using 11,500-13,150mg/L vegetable oil or diesel polluted water. A total of 47.6-176.4L clean water was collected after four cycles of filtration and centrifugation. The separating process depended on filter's structure (packing density) and properties of model oils. The wetted filters which absorbed up to 795.6g (32.31g/g) of oils were centrifuged to recover 80-91% of the oils. The sorption capacity appeared to become constant until 4 cycles of filtration after an apparent drop of 1-6g/g in the second cycle, because of unrecoverable residual oil (2-5g/g). The decrease of flow rates was favorable to filtration of low viscous oil. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Waste water reuse pathways for processing tomato

    DEFF Research Database (Denmark)

    Battilani, A; Plauborg, Finn; Andersen, Mathias Neumann

      Direct or indirect water reuse involves several aspects: contamination by faecal, inorganic and xenobiotic pollutants; high levels of suspended solids and salinity; rational use of the dissolved nutrients (particularly nitrogen). The challenge is apply new strategies and technologies which allows...... a safe use of waste water produced by small communities/industries (≤2000 EI) or of treated water discharged in irrigation channels. Water treatment technologies are coupled with irrigation strategies and technologies to obtain a flexible, easy to use, integrated management....

  18. Reuse and recycling of radioactive material packaging

    International Nuclear Information System (INIS)

    Gerulis, Eduardo; Zapparoli, Carlos Leonel; Barboza, Marycel Figols de

    2009-01-01

    Human development is directly linked to energy consumption. The political decisions (to this human development) result in economic, social and environmental aspects, whose magnitude should maintain the sustainability of every aspect for not to collapsing. The environmental aspect has been a target of research because of the excessive emission of gases which contributes to the greenhouse effect. The production processes emit gases due to the consumption of energy to get it, but it is necessary to maintain the environmental sustainability in order to minimize the contribution to the emission of greenhouse gases. The population control and the energetic efficiency are factors that contribute to the environmental sustainability. Besides them, the culture of consumption is another factor that, when applied to the reduction of emissions, also contributes to the sustainability of the environment. The reuse of materials is one of the sub-factors which contribute to the reduction of emissions. The Radiopharmacy Directory (DIRF) at IPEN-CNEN/SP, produces radiopharmaceuticals that are necessary to improve the Brazilian population's life quality. The radiopharmaceuticals are transported in packaging to the transport of radioactive material. These packages are considered non-biodegradable, because some metals, which make up these packages, pollute the environment. These packages have increased costs, in addition, because it must be approved in tests of integrity. The reuse of packaging in favorable situations to the same purpose is a way to help the environment degradation and costs reduction. The packaging reuse in unfavorable situations disobey rules or return logistics that become effective the transport back, but the consumption culture strengthening can change this situation. This paper describes IPEN's packaging, form and quantities distribution, and the packaging that comes back to be reused. (author)

  19. Electrodialysis and water reuse novel approaches

    CERN Document Server

    Rodrigues, Marco; Ferreira, Jane

    2014-01-01

    This book presents novel techniques to evaluate electrodialysis processes, to synthesize ionic membranes and to characterize their properties. It shows the potential use of membrane process to the treatment of effluents generated in many industrial sectors such as refineries, leather industries, mining and electroplating processes. The book is based on the results obtained by the author's research group during the past decade. It is useful for students, researchers and engineers interested in membrane technologies for water reuse.

  20. Assessment and reuse of secondary batteries cells

    Science.gov (United States)

    Schneider, E. L.; Kindlein, W.; Souza, S.; Malfatti, C. F.

    The popularity of portable electronic devices and the ever-growing production of the same have led to an increase in the use of rechargeable batteries. These are often discarded even before the end of their useful life. This, in turn, leads to great waste in material and natural resources and to contamination of the environment. The objective of this study was thus to develop a methodology to assess and reuse NiMH battery cells that have been disposed of before the end of their life cycle, when they can still be used. For such, the capacity of these cells, which were still in good operating conditions when the batteries were discarded, was assessed, and the percentage was estimated. The results reveal that at the end of the assessment process, a considerable number of these cells still had reuse potential, with approximately 37% of all discarded and tested cells being approved for reuse. The methodology introduced in this study showed it is possible to establish an environmentally correct alternative to reduce the amount of this sort of electronic trash.

  1. Susceptibility of central Red Sea corals during a major bleaching event

    KAUST Repository

    Furby, Kathryn A.

    2013-01-04

    A major coral bleaching event occurred in the central Red Sea near Thuwal, Saudi Arabia, in the summer of 2010, when the region experienced up to 10-11 degree heating weeks. We documented the susceptibility of various coral taxa to bleaching at eight reefs during the peak of this thermal stress. Oculinids and agaricids were most susceptible to bleaching, with up to 100 and 80 % of colonies of these families, respectively, bleaching at some reefs. In contrast, some families, such as mussids, pocilloporids, and pectinids showed low levels of bleaching (<20 % on average). We resurveyed the reefs 7 months later to estimate subsequent mortality. Mortality was highly variable among taxa, with some taxa showing evidence of full recovery and some (e. g., acroporids) apparently suffering nearly complete mortality. The unequal mortality among families resulted in significant change in community composition following the bleaching. Significant factors in the likelihood of coral bleaching during this event were depth of the reef and distance of the reef from shore. Shallow reefs and inshore reefs had a higher prevalence of bleaching. This bleaching event shows that Red Sea reefs are subject to the same increasing pressures that reefs face worldwide. This study provides a quantitative, genus-level assessment of the vulnerability of various coral groups from within the Red Sea to bleaching and estimates subsequent mortality. As such, it can provide valuable insights into the future for reef communities in the Red Sea. © 2013 Springer-Verlag Berlin Heidelberg.

  2. Nonvital tooth bleaching: a review of the literature and clinical procedures.

    Science.gov (United States)

    Plotino, Gianluca; Buono, Laura; Grande, Nicola M; Pameijer, Cornelis H; Somma, Francesco

    2008-04-01

    Tooth discoloration varies in etiology, appearance, localization, severity, and adhesion to tooth structure. It can be defined as being extrinsic or intrinsic on the basis of localization and etiology. In this review of the literature, various causes of tooth discoloration, different bleaching materials, and their applications to endodontically treated teeth have been described. In the walking bleach technique the root filling should be completed first, and a cervical seal must be established. The bleaching agent should be changed every 3-7 days. The thermocatalytic technique involves placement of a bleaching agent in the pulp chamber followed by heat application. At the end of each visit the bleaching agent is left in the tooth so that it can function as a walking bleach until the next visit. External bleaching of endodontically treated teeth with an in-office technique requires a high concentration gel. It might be a supplement to the walking bleach technique, if the results are not satisfactory after 3-4 visits. These treatments require a bonded temporary filling or a bonded resin composite to seal the access cavity. There is a deficiency of evidence-based science in the literature that addresses the prognosis of bleached nonvital teeth. Therefore, it is important to always be aware of the possible complications and risks that are associated with the different bleaching techniques.

  3. Differential Response of Coral Assemblages to Thermal Stress Underscores the Complexity in Predicting Bleaching Susceptibility.

    Directory of Open Access Journals (Sweden)

    Loke Ming Chou

    Full Text Available Coral bleaching events have been predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes is dependent on many factors and an understanding of these underlying drivers is crucial for conservation management. In 2013, a mild bleaching episode ensued in response to elevated sea temperature on the sediment-burdened reefs in Singapore. Surveys of seven sites highlighted variable bleaching susceptibility among coral genera-Pachyseris and Podabacia were the most impacted (31% of colonies of both genera bleached. The most susceptible genera such as Acropora and Pocillopora, which were expected to bleach, did not. Susceptibility varied between less than 6% and more than 11% of the corals bleached, at four and three sites respectively. Analysis of four of the most bleached genera revealed that a statistical model that included a combination of the factors (genus, colony size and site provided a better explanation of the observed bleaching patterns than any single factor alone. This underscored the complexity in predicting the coral susceptibility to future thermal stress events and the importance of monitoring coral bleaching episodes to facilitate more effective management of coral reefs under climate change.

  4. YouTube as a source of information on skin bleaching: a content analysis.

    Science.gov (United States)

    Basch, C H; Brown, A A; Fullwood, M D; Clark, A; Fung, I C-H; Yin, J

    2017-12-18

    Skin bleaching is a common, yet potentially harmful body modification practice. To describe the characteristics of the most widely viewed YouTube™ videos related to skin bleaching. The search term 'skin bleaching' was used to identify the 100 most popular English-language YouTube videos relating to the topic. Both descriptive and specific information were noted. Among the 100 manually coded skin-bleaching YouTube videos in English, there were 21 consumer-created videos, 45 internet-based news videos, 30 television news videos and 4 professional videos. Excluding the 4 professional videos, we limited our content categorization and regression analysis to 96 videos. Approximately 93% (89/96) of the most widely viewed videos mentioned changing how you look and 74% (71/96) focused on bleaching the whole body. Of the 96 videos, 63 (66%) of videos showed/mentioned a transformation. Only about 14% (13/96) mentioned that skin bleaching is unsafe. The likelihood of a video selling a skin bleaching product was 17 times higher in internet videos compared with consumer videos (OR = 17.00, 95% CI 4.58-63.09, P YouTube video on skin bleaching was uploaded by an internet source. Videos made by television sources mentioned more information about skin bleaching being unsafe, while consumer-generated videos focused more on making skin-bleaching products at home. © 2017 British Association of Dermatologists.

  5. Thermal stress exposure, bleaching response, and mortality in the threatened coral Acropora palmata.

    Science.gov (United States)

    Williams, D E; Miller, M W; Bright, A J; Pausch, R E; Valdivia, A

    2017-11-15

    Demographic data for Elkhorn coral, Acropora palmata, and in situ water temperature data from seven upper Florida Keys (USA) reefs revealed three warm thermal stress events between 2010 and 2016. During a mild bleaching event in 2011, up to 59% of colonies bleached, but no mortality resulted. In both 2014 and 2015, severe and unprecedented bleaching was observed with up to 100% of colonies bleached. A. palmata live tissue cover declined by one-third following the 2014-2015 events. Colony mortality of mildly- and non-bleached colonies did not differ but increased significantly with more severe bleaching. Increased bleaching prevalence corresponded to maximum daily average water temperatures above 31.3°C. However, the cumulative days with daily average exceeding 31.0°C provided a better predictor of bleaching response. The bleaching response of surviving colonies in 2015 was not consistent with acclimatization as most individual colonies bleached at least as badly as in 2014. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. From research to innovation: The case of biotechnical pulp bleaching

    Energy Technology Data Exchange (ETDEWEB)

    Miettinen, R.

    1996-05-01

    The paper studies the emergence and development of a research-based innovation, enzyme-aided bleaching of kraft pulp. The idea of a new bleaching method was formulated in a meeting at the Biotechnical Laboratory of Technical Research Centre of Finland (VTT) in January 1984. The method was based on the use of hemicellulases. The Biotechnology Laboratory has actively studied hemicellulases for several years and they were hence immediately available for experiments. The Biotechnology Laboratory collaborated with the Fibre Chemistry Laboratory of the Finnish Pulp and Paper Research Institute (FPPRI), which knew different kinds of pulps and was skilled in the analysis of their paper technical qualities. With this combination of knowledge the results were achieved without delay.

  7. Effects of bleaching on mercury ion release from dental amalgam.

    Science.gov (United States)

    Al-Salehi, S K

    2009-03-01

    The chemical reactions that take place at the amalgam surface when exposed to bleaching agents are not well-understood. It is known, however, that mercury ions are released from dental amalgam when bleached. We hypothesized that increasing concentrations of hydrogen peroxide are more effective than water at increasing mercury ion release from dental amalgam. We prepared dental amalgam discs (n = 65) by packing amalgam into cylindrical plastic molds and divided them into 13 equal groups of 5 discs each. The discs in each group were individually immersed in either 0%, 3.6%, 6%, or 30% (w/v) hydrogen peroxide at exposure periods of 1, 8, 48, and 168 hrs. Samples were taken for mercury ion release determination by inductively coupled plasma mass spectrometry. There were significant increases in mercury release between control and all other hydrogen peroxide concentrations at all exposure times (p < 0.05).

  8. Multicolor bleach-rate imaging enlightens in vivo sterol transport

    DEFF Research Database (Denmark)

    Wüstner, Daniel; Sage, Daniel

    2011-01-01

    , dehydroergosterol (DHE) in the genetically tractable model organism Caenorhabditis elegans (C. elegans). DHE is structurally very similar to cholesterol and ergosterol, two sterols used by the sterol-auxotroph nematode. We developed a new computational method measuring fluorophore bleaching kinetics at every pixel...... with a lysosomal marker, GFP-LMP1. Our new methods hold great promise for further studies on endosomal sterol transport in C. elegans....

  9. Fracture resistance of teeth submitted to several internal bleaching protocols.

    Science.gov (United States)

    Leonardo, Renato de Toledo; Kuga, Milton Carlos; Guiotti, Flávia Angélica; Andolfatto, Carolina; Faria-Júnior, Norberto Batista de; Campos, Edson Alves de; Keine, Kátia Cristina; Dantas, Andrea Abi Rached

    2014-03-01

    The aim of this study was to evaluate the fracture resistance of teeth submitted to several internal bleaching protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP), 15% hydrogen peroxide with titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser or sodium perborate (SP). After endodontic treatment, fifty bovine extracted teeth were divided into five groups (n = 10): G1-unbleached; G2-35HP; G3-37CP; G4-15HPTiO2 photoactivated by LED-laser and G5-SP. In the G2 and G4, the bleaching protocol was applied in 4 sessions, with 7 days intervals between each session. In the G3 and G5, the materials were kept in the pulp teeth for 21 days, but replaced every 7 days. After 21 days, the teeth were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until teeth fracture. The data were submitted to ANOVA and Tukey tests (α = 5%). The 35HP, 37CP, 15HPTiO2 and SP showed similar fracture resistance teeth reduction (p > 0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p endodontically-treated teeth, but there were no differences between each other. There are several internal bleaching protocols using hydrogen peroxide in different concentrations and activation methods. This study evaluated its effects on fracture resistance in endodontically-treated teeth.

  10. Properties of the filtrate from treatment of pig manure by filtration method

    Directory of Open Access Journals (Sweden)

    Makara Agnieszka

    2017-02-01

    Full Text Available This paper presents properties of filtrate obtained from pig manure using the AMAK treatment process, which includes the mineralization of macro- and microfertilizer components by the hydrolyzing of organic matter into forms that are bioavailable to plants. Filtration produced two products, sediment and filtrate. The quality of the filtrate allowed for its use as a substitute of water to irrigate crops. Concentrations of heavy metals are very low and therefore the quality of the filtrate fully complies with European standard concerning fertilizers. The used mineralization process practically eliminated odors from the filtrate. The reduction of specific odor emission by 99.1-99.5% in samples taken from above the filtrate, respectively compared to the odor concentration found in samples taken from above raw pig manure. Sediment could be used as raw material for production of mineral-organic fertilizer. Filtrate and filtration sediments analyses show that the majority of nitrogen and other fertilizing compounds included in raw pig manure remains in sediment.

  11. Biodegradability and toxicity assessment of bleach plant effluents treated anaerobically.

    Science.gov (United States)

    Chaparro, T R; Botta, C M; Pires, E C

    2010-01-01

    As part of an experimental project on the treatment of bleach plant effluents the results of biodegradability and toxicity assessment of effluents from a bench-scale horizontal anaerobic immobilized bioreactor (HAIB) are discussed in this paper. The biodegradability of the bleach plant effluents from a Kraft pulp mill treated in the HAIB was evaluated using the modified Zahn-Wellens test. The inoculum came from a pulp mill wastewater treatment plant and the dissolved organic carbon (DOC) was used as the indicator of organic matter removal. The acute and chronic toxicity removal during the anaerobic treatment was estimated using Daphnia similis and Ceriodaphnia silvestrii respectively. Moreover, the evaluation of chromosome aberrations (CA), micronucleus frequencies (MN) and mitotic index (IM) in Allium cepa cells were used as genotoxicity indicators. The results indicate that the effluents from the anaerobic reactor are amenable to aerobic polishing. Acute and chronic toxicity were reduced by 90 and 81%, respectively. The largest CA and MN incidence in the meristematic cells of A. cepa were observed after exposure to the raw bleach plant effluent. The HAIB was able to reduce the acute and chronic toxicity as well as chromosome aberrations and the occurrence of micronucleus.

  12. Fracture resistance of bleached teeth restored with different procedures

    Directory of Open Access Journals (Sweden)

    Matheus Coelho Bandéca

    2012-08-01

    Full Text Available This study evaluated the fracture resistance of teeth submitted to internal bleaching and restored with different non-metallic post. Eighty mandibular incisors were endodontically treated and randomly divided in 10 groups (n = 8: G1- restored with composite resin (CR, G2- CR + fiber-reinforced composite post (FRC, Everstick post, Sticktech cemented with resin cement self-etch adhesive (RCS, Panavia F 2.0, Kuraray, G3- CR + FRC + self-adhesive resin cement (SRC, Breeze, Pentral Clinical, G4- CR+ glass fiber post (GF, Exacto Post, Angelus + RCS, G5- CR + GF + SRC. The G6 to G10 were bleached with hydrogen peroxide (HP and restored with the same restorative procedures used for G1 to G5, respectively. After 7 days storage in artificial saliva, the specimens were submitted to the compressive strength test (N at 0.5 mm/min cross-head speed and the failure pattern was identified as either reparable (failure showed until 2 mm below the cement-enamel junction or irreparable (the failure showed <2 mm or more below the cement-enamel. Data were analyzed by ANOVA and Tukey test (α = 0.05. No significant difference (p < 0.05 was found among G1 to G10. The results suggest that intracoronal bleaching did not significantly weaken the teeth and the failure patterns were predominately reparable for all groups. The non-metallic posts in these teeth did not improve fracture resistance.

  13. Peroxide dental bleaching via laser microchannels and tooth color measurements

    Science.gov (United States)

    Altshuler, Gregory; Belikov, Andrey; Skrypnik, Alexei; Feldchtein, Felix; Pushkareva, Alexandra; Shatilova, Ksenia; Cernavin, Igor; Tuchin, Valery

    2016-12-01

    The aim of this study was to use microchannels drilled by an Er:YAG laser into a human tooth through the enamel into the dentin for direct injection of hydrogen peroxide (HP) to produce a minimally invasive, rapid, tooth bleaching effect. The experiments were conducted in vitro. Five microchannels with a diameter of ˜200 μm and a depth of ˜2 mm were drilled through the palatal side of a human tooth crown using the microbeam of an Er:YAG-laser with a wavelength of 2.94 μm. After injection of an aqueous solution of 31%-HP through the microchannels, the tooth color was evaluated using a VITA shade guide and International Commission on Illumination L*ab color parameters. A tooth model used for the evaluation of the distribution of HP concentration was created and the amount of HP which can be injected into tooth dentin to bleach it safely was estimated. Injection of 1.5±0.1 mm3 of 31%-HP into the tooth led to noticeable bleaching within 3 h and significant improvement of tooth color within 24 h.

  14. Post-treatment of anaerobic reactor effluent using coagulation/oxidation followed by double filtration.

    Science.gov (United States)

    Cavallini, Grasiele Soares; de Sousa Vidal, Carlos Magno; de Souza, Jeanette Beber; de Campos, Sandro Xavier

    2016-04-01

    This study evaluates the efficacy of a sanitary sewage treatment system, proposing post-treatment of the effluent generated by the upflow anaerobic sludge blanket UASB reactor, through a Fenton coagulation/oxidation ((ferric chloride (FC) or ferrous sulfate (FS) and peracetic acid (PAA)), followed by a double filtration system, composed of a gravel ascending drainage filter and a sand descending filter. Following the assessment of treatability, the system efficiency was evaluated using physicochemical and microbiological parameters. In all treatments performed in the pilot unit, total suspended solids (TSS) were completely removed, leading to a decrease in turbidity greater than 90% and close to 100% removal of total phosphorous. In the FC and PAA combination, the effluent was oxygenated prior to filtration, enabling a more significant removal of biochemical oxygen demand (BOD), which characterizes aerobic degradation even in a quick sand filter. The treatments carried out in the presence of the PAA oxidizing agent showed a more significant bleaching of the effluent. Concerning the microbiological parameters, the simultaneous use of PAA and FC contributed to the partial inactivation of the assessed microorganisms. A 65% recovery of the effluent was obtained with the proposed treatment system, considering the volume employed in filter backwashing.

  15. Ultrafiltration to reuse laundering wash water

    DEFF Research Database (Denmark)

    Giagnorio, Mattia; Søtoft, Lene Fjerbæk; Tiraferri, Alberto

    2017-01-01

    Laundering industry consumes and discharges large amounts of water and surfactants, and the demand of surface active agents used for washing is increasing worldwide. Some of these substances are considered contaminants of emerging concern, as they persist in the environment. This work aimed...... and ceramic membranes. Wash water samples were collected at an industrial laundering facility for hospital linen and filtered through different ultrafiltration membranes with varying molecular weight cut-off. The critical micelle concentration of the detergent was quantified, and capillarity measurements were...... used to determine the concentration of free surfactants in water. The system was designed to comprise two filtration steps in series: a pre-filtration step did not allow recovery of surfactant or the production of a high quality permeate, but it was necessary to remove large contaminants...

  16. Trace elementary concentration in enamel after dental bleaching using HI-ERDA

    Energy Technology Data Exchange (ETDEWEB)

    Added, N. [GFAA, Depto de Fisica Nuclear, IFUSP, University of Sao Paulo, Travessa R da rua do Matao 187, Cidade Universitaria, Caixa Postal 66318, CEP 05508-970 Sao Paulo, SP (Brazil)]. E-mail: nemitala@dfn.if.usp.br; Rizzutto, M.A. [GFAA, Depto de Fisica Nuclear, IFUSP, University of Sao Paulo, Travessa R da rua do Matao 187, Cidade Universitaria, Caixa Postal 66318, CEP 05508-970 Sao Paulo, SP (Brazil); Curado, J.F. [GFAA, Depto de Fisica Nuclear, IFUSP, University of Sao Paulo, Travessa R da rua do Matao 187, Cidade Universitaria, Caixa Postal 66318, CEP 05508-970 Sao Paulo, SP (Brazil); Francci, C. [School of Dentistry, University of Sao Paulo (Brazil); Markarian, R. [School of Dentistry, University of Sao Paulo (Brazil); Mori, M. [School of Dentistry, University of Sao Paulo (Brazil)

    2006-08-15

    Changes of elementary concentrations in dental enamel after a bleaching treatment with different products, is presented, with special focus on the oxygen contribution. Concentrations for Ca, P, O and C and some other trace elements were obtained for enamel of bovine incisor teeth by HI-ERDA measurements using a {sup 35}Cl incident beam and an ionization chamber. Five groups of teeth with five samples each were treated with a different bleaching agents. Each tooth had its crown sectioned in two halves, one for bleaching test and one the other used as a control. Average values of C/Ca, O/Ca, F/Ca enrichment factors were found. The comparison between bleached and non-bleached halves indicates that bleaching treatment did not affect the mineral structure when low-concentration whitening systems were used. The almost constant oxygen concentration in enamel, suggests little changes due to whitening therapy.

  17. Improving the hydrogen peroxide bleaching efficiency of aspen chemithermomechanical pulp by using chitosan.

    Science.gov (United States)

    Li, Zongquan; Dou, Hongyan; Fu, Yingjuan; Qin, Menghua

    2015-11-05

    The presence of transition metals during the hydrogen peroxide bleaching of pulp results in the decomposition of hydrogen peroxide, which decreases the bleaching efficiency. In this study, chitosans were used as peroxide stabilizer in the alkaline hydrogen peroxide bleaching of aspen chemithermomechanical pulp (CTMP). The results showed that the brightness of the bleached CTMP increased 1.5% ISO by addition of 0.1% chitosan with 95% degree of deacetylation during peroxide bleaching. Transition metals in the form of ions or metal colloid particles, such as iron, copper and manganese, could be adsorbed by chitosans. Chitosans could inhibit the decomposition of hydrogen peroxide catalyzed by different transition metals under alkaline conditions. The ability of chitosans to inhibit peroxide decomposition depended on the type of transition metals, chitosan concentration and degree of deacetylation applied. The addition of chitosan slightly reduced the concentration of the hydroxyl radical formed during the hydrogen peroxide bleaching of aspen CTMP. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Natural Zeolite Sample and Investigation Its Use in Oil Bleaching Sector

    Science.gov (United States)

    Bilgin, Oyku

    2017-12-01

    In the sector of oil bleaching, the stored raw oil is subjected to physical and chemical methods such as degumming, neutralization, bleaching, deodorization and winterization. In the process of oil bleaching, the selection of correct bleaching earth in accordance with oil characteristics matters so much. Bleaching earth is an inorganic product used in removing impurities being available within the structures of vegetable, animal oil (sunflower, soya, corn, palm, tallow, rapeseed, fish oils…etc.) and fatty acids, mineral oils (glycerine, paraffin, mineral motor oils. etc.) with the adsorption process. The factors such as low cost of oil bleaching earth, low ratio of oil retaining, high bleaching capacity in spite of using them in small amounts, filter’s delayed blocking by the earth and non-increase of the free acidity of the oil should be taken into consideration. Bleaching earths are processed with some acids in order to widen their surface areas. During this process, a certain amount of acid is left within oil bleaching earths even if it is very little. These acids also increase oil’s acidity by oxidizing oil in the course of bleaching process. In this study, zeolite sample taken from Manisa -Demirci region was used. Following the processes of crushing and sieving, zeolite sample was subjected to chemical analyses according to their grain thickness, microscopic examination, the analyses of XRD and cation exchange capacity and their ore characteristics were determined. Afterwards, it was searched whether zeolite sample has oil bleaching ability or not or whether it can be used as oil bleaching earth or not.

  19. Durability of bleaching results achieved with 15% carbamide peroxide and 38% hydrogen peroxide in vitro.

    Science.gov (United States)

    Knösel, Michael; Reus, Monika; Rosenberger, Albert; Attin, Thomas; Ziebolz, Dirk

    2011-01-01

    The aim of this study was to assess the durability of bleaching results achieved with (1) 15% carbamide peroxide home bleaching and (2) 38% hydrogen peroxide in-office bleaching. A total of 231 extracted anterior teeth were randomly divided into three groups (n = 77 in each group) with comparable mean baseline L*-values (68.24 ± 0.8): a non-bleached control group A, a 15% carbamide peroxide group B (5 bleaching intervals of 8 hours), and a 38% hydrogen peroxide group C (3 intervals of 15 minutes). Durability of bleaching was assessed by comparing CIE-L*a*b* data after intervals of 2, 4, 12, and 26 weeks from baseline. Both bleaching regimes initially produced a highly significant increase in lightness parameter L*, with no significant difference between the respective bleaching regimes (B: 68.23 / 72.48; C: 68.32 / 73.25). Six months after starting the trial, L*-values for group B yielded no significant differences compared to baseline (69.55), whereas L*-values for group C were still significantly raised (69.91), despite a highly significant decrease when compared to initial bleaching results. In both treatment groups, there was a lasting response to bleaching in terms of CIE-a* and -b* value decreases. Results for both home- and in-practice regimes were found to be similar for about 12 weeks. However, in-office results were longer lasting, despite the shorter treatment intervals. Summarized bleaching effects, in terms of delta E values, revealed no significant differences between treatment groups and the control group after 6 months, indicating an abatement of the bleaching results achieved.

  20. Performance Efficient Launch Vehicle Recovery and Reuse

    Science.gov (United States)

    Reed, John G.; Ragab, Mohamed M.; Cheatwood, F. McNeil; Hughes, Stephen J.; Dinonno, J.; Bodkin, R.; Lowry, Allen; Brierly, Gregory T.; Kelly, John W.

    2016-01-01

    For decades, economic reuse of launch vehicles has been an elusive goal. Recent attempts at demonstrating elements of launch vehicle recovery for reuse have invigorated a debate over the merits of different approaches. The parameter most often used to assess the cost of access to space is dollars-per-kilogram to orbit. When comparing reusable vs. expendable launch vehicles, that ratio has been shown to be most sensitive to the performance lost as a result of enabling the reusability. This paper will briefly review the historical background and results of recent attempts to recover launch vehicle assets for reuse. The business case for reuse will be reviewed, with emphasis on the performance expended to recover those assets, and the practicality of the most ambitious reuse concept, namely propulsive return to the launch site. In 2015, United Launch Alliance (ULA) announced its Sensible, Modular, Autonomous Return Technology (SMART) reuse plan for recovery of the booster module for its new Vulcan launch vehicle. That plan employs a non-propulsive approach where atmospheric entry, descent and landing (EDL) technologies are utilized. Elements of such a system have a wide variety of applications, from recovery of launch vehicle elements in suborbital trajectories all the way to human space exploration. This paper will include an update on ULA's booster module recovery approach, which relies on Hypersonic Inflatable Aerodynamic Decelerator (HIAD) and Mid-Air Retrieval (MAR) technologies, including its concept of operations (ConOps). The HIAD design, as well as parafoil staging and MAR concepts, will be discussed. Recent HIAD development activities and near term plans including scalability, next generation materials for the inflatable structure and heat shield, and gas generator inflation systems will be provided. MAR topics will include the ConOps for recovery, helicopter selection and staging, and the state of the art of parachute recovery systems using large parafoils

  1. Dynamic Membrane Technology for Printing Wastewater Reuse

    Science.gov (United States)

    Liu, Lin; Lu, Xujie; Chen, Jihua

    As environmental regulations become rigid and the cost of freshwater increases, wastewater is considered as a major resource in China. The paper presented a study on the implementation of the advanced treatment process using dynamic membrane (DM) in reusing of printing wastewater. The DM was well formed by circulating 1.5g/L of PAC in 20 minutes, the trans-membrane pressure of 200 kPa and the cross-flow velocity of 0.75m/s. The printing effluents were treated in effluent treatment plants comprising a physicochemical option followed by biological process. The treated effluent contained chemical oxygen demand (COD), color and turbidity in the range of 45-60 mg/L, 0.030-0.045 (absorbance at 420 nm) and 3-5 NTU. The results showed that the COD, color and turbidity removal efficiencies of the DM permeate were 84%, 85% and 80%, respectively. The wastewater treated by DM was reused as process water and the final concentrated retentate could be discharged directly into sewage treatment works with no additional treatments. Cleaning and regeneration of DM were very convenient if necessary. The proper process was that the polluted DM was cleaned with tap water at high cross-flow velocity. When irreversible pollutants accumulate, it would be rinsed with chemicals tested and the membrane flux would be restored up to 95%. The result showed that DM was considered as a promising method for purification aimed at reuse of printing wastewater, resulting in direct environmental and economic benefits.

  2. Effects of bleaching agents and Tooth Mousse(™) on human enamel hardness.

    Science.gov (United States)

    Alkhtib, Asmaa; Manton, David J; Burrow, Michael F; Saber-Samandari, Saeed; Palamara, Joseph E A; Gross, Kārlis A; Reynolds, Eric C

    2013-05-01

    The aim of this laboratory study was to investigate the effect of three commercial bleaching agents and Tooth Mousse(™) containing 10% w/w casein phosphopeptide-amorphous calcium phosphate on the hardness of tooth enamel. Sixteen human enamel specimens were exposed to one of three commercial bleaching agents with or without subsequent exposure to Tooth Mousse(™) . Nanoindentation was used to measure the hardness and reduced modulus before and after treatments. When bleaching materials were applied for a short period of time following the manufacturers' instructions, there was an increase in enamel hardness and reduced modulus for some bleaching groups, with no statistically significant difference from the baseline values. After extended bleaching periods a statistically significant decrease in enamel hardness and reduced modulus was found and after applying Tooth Mousse(™) post-bleaching, the hardness and reduced modulus returned to close to baseline values. The application of bleaching agents for an extended period of time significantly decreases enamel hardness and the reduced modulus. The application of Tooth Mousse(™) after bleaching was able to reestablish the baseline enamel hardness and reduced modulus, decreasing the adverse effects of bleaching enamel. © 2012 Wiley Publishing Asia Pty Ltd.

  3. Use of the LM-OSL technique for the detection of partial bleaching in quartz

    DEFF Research Database (Denmark)

    Larsen, N.A.; Bulur, E.; Bøtter-Jensen, L.

    2000-01-01

    is known as linear modulation OSL (LM-OSL). In controlled laboratory conditions, this technique has been employed to study the ease-of-bleaching of the trapped charge in quartz by comparing the OSL curves of quartz aliquots which have been either: (1) fully bleached, followed by a laboratory dose of beta...... -irradiation, or (2) partially bleached, followed by the laboratory beta -dose. The ratio of the OSL signals due to the beta -dose from the partly and fully bleached aliquots is illustrated to be a potential indicator of the degree of optical resetting of the OSL signal in dating material. The key parameter...

  4. Susceptibility to Coffee Staining during Enamel Remineralization Following the In-Office Bleaching Technique

    DEFF Research Database (Denmark)

    Mori, Aline Akemi; Lima, Fernanda Ferruzzi; Benetti, Ana Raquel

    2016-01-01

    PURPOSE: To assess in situ the enamel mineralization level and susceptibility to coffee staining after in-office bleaching. MATERIALS AND METHODS: Thirty-six human dental fragments assembled into intraoral devices were bleached with 35% hydrogen peroxide and treated as follows: (group 1) no contact......-office bleaching was progressively reversed by contact with saliva for 14 days. The whiteness index was not affected by contact with coffee during the remineralization period. CLINICAL SIGNIFICANCE: The results of this in situ study suggest that the mineral loss caused by in-office dental bleaching is minimal...

  5. Comparison of Flexural Strength of Resin Cements After Storing in Different Media and Bleaching Agents.

    Science.gov (United States)

    Geramipanah, Farideh; Rezaei, Susan Mir Mohammad; Jafary, Maryam; Sadighpour, Leyla

    2015-06-01

    The aim of this study was to determine the effects of different storage media and bleaching treatments on the flexural strength of two resin cements (Panavia and BisCem). One hundred rectangular-shaped specimens were prepared with two resin cements and were stored in five media types (n = 10): distilled water (DW), lactic acid (LA), sodium hydroxide (NH), in-office bleaching (OB) and home bleaching (HB). There was significant interaction between the solutions and cements (p except Panavia in OB) (p exception of in-office bleaching.

  6. A Study for Tooth Bleaching via Carbamide Peroxide-Loaded Hollow Calcium Phosphate Spheres

    Directory of Open Access Journals (Sweden)

    Tao Qin

    2016-12-01

    Full Text Available The objective of this study was to investigate if a prolonged bleaching effect of carbamide peroxide-loaded hollow calcium phosphate spheres (HCPS can be achieved. HCPS was synthesized via a hydrothermal reaction method. Carbamide peroxide (CP was-loaded into HCPS by mixing with distilled water as solvent. We developed two bleaching gels containing CP-loaded HCPS: one gel with low HP concentration as at-home bleaching gel, and one with high HP concentration as in-office gel. Their bleaching effects on stained human permanent posterior teeth were investigated by measuring the color difference before and after bleaching. The effect of gels on rhodamine B degradation was also studied. To investigate the potential effect of remineralization of using HCPS, bleached teeth were soaked in phosphate buffer solution (PBS containing calcium and magnesium ions. Both bleaching gels had a prolonged whitening effect, and showed a strong ability to degrade rhodamine B. After soaking in PBS for 3 days, remineralization was observed at the sites where HCPS attached to the teeth surface. CP-loaded HCPS could prolong the HP release behavior and improve the bleaching effect. HCPS was effective in increasing the whitening effect of carbamide peroxide and improving remineralization after bleaching process.

  7. Inflammatory response of human dental pulp to at-home and in-office tooth bleaching

    Directory of Open Access Journals (Sweden)

    Maysa Magalhães Vaz

    Full Text Available ABSTRACT Tooth bleaching is a technique of choice to obtain a harmonious smile, but bleaching agents may damage the dental pulp. Objective: This study evaluated the inflammatory responses of human dental pulp after the use of two bleaching techniques. Material and Methods: Pulp samples were collected from human third molars extracted for orthodontic reasons and divided into three groups: control - no tooth bleaching (CG (n=7; at-home bleaching with 15% carbamide peroxide (AH (n = 10, and in-office bleaching with 38% hydrogen peroxide (IO (n=12. Pulps were removed and stained with hematoxylin-eosin for microscopic analysis of inflammation intensity, collagen degradation, and pulp tissue organization. Immunohistochemistry was used to detect mast cells (tryptase+, blood vessels (CD31+, and macrophages (CD68+. Chi-square, Kruskal-Wallis, and Mann Whitney tests were used for statistical analysis. The level of significance was set at p0.05. No mast cells were found in the pulp samples analyzed. Conclusion: In-office bleaching with 38% hydrogen peroxide resulted in more intense inflammation, higher macrophages migration, and greater pulp damage then at-home bleaching with 15% carbamide peroxide, however, these bleaching techniques did not induce migration of mast cells and increased the number of blood vessels.

  8. New Insights on Degumming and Bleaching Process Parameters on The Formation of 3-Monochloropropane-1,2-Diol Esters and Glycidyl Esters in Refined, Bleached, Deodorized Palm Oil.

    Science.gov (United States)

    Sim, Biow Ing; Muhamad, Halimah; Lai, Oi Ming; Abas, Faridah; Yeoh, Chee Beng; Nehdi, Imededdine Arbi; Khor, Yih Phing; Tan, Chin Ping

    2018-04-01

    This paper examines the interactions of degumming and bleaching processes as well as their influences on the formation of 3-monochloropropane-1,2-diol esters (3-MCPDE) and glycidyl esters in refined, bleached and deodorized palm oil by using D-optimal design. Water degumming effectively reduced the 3-MCPDE content up to 50%. Acid activated bleaching earth had a greater effect on 3-MCPDE reduction compared to natural bleaching earth and acid activated bleaching earth with neutral pH, indicating that performance and adsorption capacities of bleaching earth are the predominant factors in the removal of esters, rather than its acidity profile. The combination of high dosage phosphoric acid during degumming with the use of acid activated bleaching earth eliminated almost all glycidyl esters during refining. Besides, the effects of crude palm oil quality was assessed and it was found that the quality of crude palm oil determines the level of formation of 3-MCPDE and glycidyl esters in palm oil during the high temperature deodorization step of physical refining process. Poor quality crude palm oil has strong impact towards 3-MCPDE and glycidyl esters formation due to the intrinsic components present within. The findings are useful to palm oil refining industry in choosing raw materials as an input during the refining process.

  9. Design reuse in product shape modeling : A study of freeform feature reuse by signal processing techniques

    NARCIS (Netherlands)

    Wang, C.

    2005-01-01

    Lack of facilities in supporting design reuse is a serious problem in product shape modeling, especially in computer-aided design systems. This becomes a bottleneck of fast shape conceptualization and creation in consumer product design, which consequently prohibits creativity and innovation. In the

  10. Effect of coffe and a cola-based soft drink on the color stability of bleached bovine incisors considering the time elapsed after bleaching

    Directory of Open Access Journals (Sweden)

    Rodrigo PIROLO

    2014-12-01

    Full Text Available There is no consensus about the waiting time necessary for the patient to start consuming beverages containing colorants again after bleaching. Objective: To evaluate the influence of beverages with coloring agents on bleached bovine incisors considering the time elapsed after bleaching. Materials and methods: Sixty bovine incisors were bleached with 35% hydrogen peroxide for in-office use (Whiteness HP Max and divided into 10 groups. The color was evaluated with a spectrophotometer (Spectro Shade MICRO before and after bleaching, employing the CIE-Lab system. After bleaching, the teeth were exposed for 5 min to coffee or cola-based soft drink (CBSD at different periods after bleaching: 10 min, 1 h, 24 h, 48 h, and 72 h. Color (∆E and lightness (∆L variations were obtained from the CIE-Lab coordinates. Data were subjected to two-way ANOVA and Tukey HSD tests (p<0.05. Results: Significant differences were observed between groups for both the ∆L and ∆E values (p<0.001. All specimens presented a decrease in brightness (negative ∆L. The highest ∆E values were observed for teeth stained with a CBSD at 10 min and 1 h (4.12 and 4.16, respectively. Teeth pigmented with coffee presented ∆E values below 3.3 units for all evaluation times. Conclusion: The exposure to coffee after bleaching causes less color changes than the exposure to a CBSD regardless of the time after bleaching.

  11. Reuse of wastewater from pulp industry for the optimization of fungal xylanase production

    Directory of Open Access Journals (Sweden)

    Geisiany Maria de Queiroz-Fernandes

    2017-05-01

    Full Text Available The production of enzymes using agro-industrial waste is a low cost alternative for the reuse of byproducts, with the subsequent impact decrease on the environment. Current analysis produced xylanase using fungus Aspergillus niger, with two types of wastewater generated during the pulp chemical bleaching phase as inducers. Xylanase was produced by submerged liquid fermentation and factorial design optimized parameters that influence production (concentration of wastewater and production period. Initial culture conditions (pH, temperature and agitation were optimized independently. Alkaline wastewater was more effective than acidic wastewater for the induction of xylanase in optimized conditions: 50% of culture medium, 7-day production, 30°C, pH 6.0 and agitation at 160 rpm. Despite different results, acidic and alkaline wastewaters induced xylanase production by A. niger when employed in concentrations lower than or equal to 50% of culture medium and in the most optimal conditions described above. Alkaline wastewater is highlighted as the most efficient for such production.

  12. Evaluation of appropriate technologies for grey water treatments and reuses.

    Science.gov (United States)

    Li, Fangyue; Wichmann, Knut; Otterpohl, Ralf

    2009-01-01

    As water is becoming a rare resource, the onsite reuse and recycling of grey water is practiced in many countries as a sustainable solution to reduce the overall urban water demand. However, the lack of appropriate water quality standards or guidelines has hampered the appropriate grey water reuses. Based on literature review, a non-potable urban grey water treatment and reuse scheme is proposed and the treatment alternatives for grey water reuse are evaluated according to the grey water characteristics, the proposed standards and economical feasibility.

  13. Paradoxical glomerular filtration of carbon nanotubes.

    Science.gov (United States)

    Ruggiero, Alessandro; Villa, Carlos H; Bander, Evan; Rey, Diego A; Bergkvist, Magnus; Batt, Carl A; Manova-Todorova, Katia; Deen, William M; Scheinberg, David A; McDevitt, Michael R

    2010-07-06

    The molecular weight cutoff for glomerular filtration is thought to be 30-50 kDa. Here we report rapid and efficient filtration of molecules 10-20 times that mass and a model for the mechanism of this filtration. We conducted multimodal imaging studies in mice to investigate renal clearance of a single-walled carbon nanotube (SWCNT) construct covalently appended with ligands allowing simultaneous dynamic positron emission tomography, near-infrared fluorescence imaging, and microscopy. These SWCNTs have a length distribution ranging from 100 to 500 nm. The average length was determined to be 200-300 nm, which would yield a functionalized construct with a molecular weight of approximately 350-500 kDa. The construct was rapidly (t(1/2) approximately 6 min) renally cleared intact by glomerular filtration, with partial tubular reabsorption and transient translocation into the proximal tubular cell nuclei. Directional absorption was confirmed in vitro using polarized renal cells. Active secretion via transporters was not involved. Mathematical modeling of the rotational diffusivity showed the tendency of flow to orient SWCNTs of this size to allow clearance via the glomerular pores. Surprisingly, these results raise questions about the rules for renal filtration, given that these large molecules (with aspect ratios ranging from 100:1 to 500:1) were cleared similarly to small molecules. SWCNTs and other novel nanomaterials are being actively investigated for potential biomedical applications, and these observations-that high aspect ratio as well as large molecular size have an impact on glomerular filtration-will allow the design of novel nanoscale-based therapeutics with unusual pharmacologic characteristics.

  14. EM Task 9 - Centrifugal membrane filtration

    International Nuclear Information System (INIS)

    Stepan, Daniel J.; Stevens, Bradley G.; Hetland, Melanie D.

    1999-01-01

    The overall project consists of several integrated research phases related to the applicability, continued development, demonstration, and commercialization of the SpinTek centrifugal membrane filtration process. Work performed during this reporting period consisted of Phase 2 evaluation of the SpinTek centrifugal membrane filtration technology and Phase 3, Technology Partnering. During Phase 1 testing conducted at the EERC using the SpinTek ST-IIL unit operating on a surrogate tank waste, a solids cake developed on the membrane surface. The solids cake was observed where linear membrane velocities were less than 17.5 ft/s and reduced the unobstructed membrane surface area up to 25%, reducing overall filtration performance. The primary goal of the Phase 2 research effort was to enhance filtration performance through the development and testing of alternative turbulence promoter designs. The turbulence promoters were designed to generate a shear force across the entire membrane surface sufficient to maintain a self-cleaning membrane capability and improve filtration efficiency and long-term performance. Specific Phase 2 research activities included the following: System modifications to accommodate an 11-in.-diameter, two-disk rotating membrane assembly; Development and fabrication of alternative turbulence promoter designs; Testing and evaluation of the existing and alternative turbulence promoters under selected operating conditions using a statistically designed test matrix; and Data reduction and analysis; The objective of Phase 3 research was to demonstrate the effectiveness of SpinTek's centrifugal membrane filtration as a pretreatment to remove suspended solids from a liquid waste upstream of 3M's WWL cartridge technology for the selective removal of technetium (Tc)

  15. Economic Assessment of an Integrated Membrane System for Secondary Effluent Polishing for Unrestricted Reuse

    Directory of Open Access Journals (Sweden)

    Gideon Oron

    2012-03-01

    Full Text Available Extra treatment stages are required to polish the secondary effluent for unrestricted reuse, primarily for agricultural irrigation. Improved technology for the removal of particles, turbidity, bacteria and cysts, without the use of disinfectants is based on MicroFiltration (MF and UltraFiltration (UF membrane technology and in series with Reverse Osmosis (RO for dissolved solids removal. Field experiments were conducted using a mobile UF and RO membrane pilot unit at a capacity of around 1.0 m3/hr. A management model was defined and tested towards optimal polishing of secondary effluent. The two major purposes of the management model are: (i to delineate a methodology for economic assessment of optimal membrane technology implementation for secondary effluent upgrading for unrestricted use, and; (ii to provide guidelines for optimal RO membrane selection in regards to the pretreatment stage. The defined linear model takes into account the costs of the feed secondary effluent, the UF pretreatment and the RO process. Technological constraints refer primarily to the longevity of the membrane and their performance. Final treatment cost (the objective function includes investment, operation and maintenance expenses, UF pretreatment, RO treatment, post treatment and incentive for low salinity permeate use. The cost range of water for irrigation according to the model is between 15 and 42 US cents per m3.

  16. The Perspective of Riverbank Filtration in China

    Science.gov (United States)

    Li, J.; Teng, Y.; Zhai, Y.; Zuo, R.

    2014-12-01

    Sustainable drinking water supply can affect the health of people, and the surrounding ecosystems. According to statistics of the monitoring program of drinking water sources in 309 at or above prefecture level of China in 2013, the major pollutants index were total phosphorus, ammonia and manganese in surface drinking water sources, respectively, iron, ammonia and manganese in groundwater drinking water sources, respectively. More than 150 drinking water emergency environmental accidents happened since 2006, 52 of these accidents led to the disruption of water supply in waterworks, and a population of over ten million were affected. It indicated that there is a potential risk for people's health by the use of river water directly and it is necessary to require alternative techniques such as riverbank filtration for improving the drinking water quality. Riverbank filtration is an inexpensive natural process, not only smoothing out normal pollutant concentration found in surface water but also significantly reducing the risk from such emergency events as chemical spill into the river. Riverbank filtration technique has been used in many countries more than 100 years, including China. In China, in 1950s, the bank infiltration technique was first applied in northeast of China. Extensive bank infiltration application was conducted in 1980s, and more than 300 drinking water sources utilities bank infiltration established mainly near the Songhua River Basin, the Yellow River Basin, Haihe River Basin. However, the comparative lack of application and researches on riverbank filtration have formed critical scientific data gap in China. As the performance of riverbank filtration technique depend on not only the design and setting such as well type, pumping rate, but also the local hydrogeology and environmental properties. We recommend more riverbank filtration project and studies to be conducted to collect related significant environmental geology data in China

  17. Statistical data filtration in neutron coincidence counting

    International Nuclear Information System (INIS)

    Beddingfield, D.H.; Menlove, H.O.

    1992-11-01

    We assessed the effectiveness of statistical data filtration to minimize the contribution of matrix materials in 200-ell drums to the nondestructive assay of plutonium. Those matrices were examined: polyethylene, concrete, aluminum, iron, cadmium, and lead. Statistical filtration of neutron coincidence data improved the low-end sensitivity of coincidence counters. Spurious data arising from electrical noise, matrix spallation, and geometric effects were smoothed in a predictable fashion by the statistical filter. The filter effectively lowers the minimum detectable mass limit that can be achieved for plutonium assay using passive neutron coincidence counting

  18. Changes in coral-associated microbial communities during a bleaching event.

    Science.gov (United States)

    Bourne, David; Iida, Yuki; Uthicke, Sven; Smith-Keune, Carolyn

    2008-04-01

    Environmental stressors such as increased sea surface temperatures are well-known for contributing to coral bleaching; however, the effect of increased temperatures and subsequent bleaching on coral-associated microbial communities is poorly understood. Colonies of the hard coral Acropora millepora were tagged on a reef flat off Magnetic Island (Great Barrier Reef) and surveyed over 2.5 years, which included a severe bleaching event in January/February 2002. Daily average water temperatures exceeded the previous 10-year average by more than 1 degrees C for extended periods with field-based visual surveys recording all tagged colonies displaying signs of bleaching. During the bleaching period, direct counts of coral zooxanthellae densities decreased by approximately 64%, before recovery to pre-bleaching levels after the thermal stress event. A subset of three tagged coral colonies were sampled through the bleaching event and changes in the microbial community elucidated. Denaturing gradient gel electrophoresis (DGGE) analysis demonstrated conserved bacterial banding profiles between the three coral colonies, confirming previous studies highlighting specific microbial associations. As coral colonies bleached, the microbial community shifted and redundancy analysis (RDA) of DGGE banding patterns revealed a correlation of increasing temperature with the appearance of Vibrio-affiliated sequences. Interestingly, this shift to a Vibrio-dominated community commenced prior to visual signs of bleaching. Clone libraries hybridized with Vibrio-specific oligonucleotide probes confirmed an increase in the fraction of Vibrio-affiliated clones during the bleaching period. Post bleaching, the coral microbial associations again shifted, returning to a profile similar to the fingerprints prior to bleaching. This provided further evidence for corals selecting and shaping their microbial partners. For non-bleached samples, a close association with Spongiobacter-related sequences were

  19. Nanotribological and Nanomechanical Properties Changes of Tooth After Bleaching and Remineralization in Wet Environment

    Science.gov (United States)

    Yu, Dandan; Gao, Shanshan; Min, Jie; Zhang, Qianqian; Gao, Shuai; Yu, Haiyang

    2015-12-01

    Teeth bleaching cases had increased with people's desire for oral aesthetic; however, bleached teeth would still undertake chewing actions and remineralizing process in saliva. Nanotribological and nanomechanical properties are proper displays for dental performance of bleached teeth. The purpose of the research was to reveal the effect of bleaching and remineralization on the nanotribological and nanomechanical properties of teeth in wet environment. The specimens were divided into four groups according to the bleaching products used: 12 % hydrogen peroxide (HP) (12HP group); 15 % carbamide peroxide (CP) (15CP group); 35 % CP (35CP group); and artificial saliva (control group). The nanotribological and nanomechanical property changes of tooth enamel after bleaching and remineralization were evaluated respectively by nanoscratch and nanoindentation tests in wet environment, imitating the wet oral environment. The morphology changes were evaluated by statistical parametric mapping (SPM) and scanning electron microscopy (SEM). After bleaching, 12HP group and 15CP group showed increased scratch depth with more pile ups on the scratch edges, decreased nanohardness, and corroded surface appearance. While the 35CP group showed an increase in nanoscratch depth, no change in nanohardness and surface appearance was observed. The control group showed no change in these measurements. After remineralization, the three bleaching groups showed decreased nanoscratch depth and no change of nanohardness compared with the bleached teeth. And the control group showed no changes in nanotribological and nanomechanical properties. The nanotribological and nanomechanical properties of the 12HP group and 15CP group were affected by bleaching, but the nanotribological properties recovered partly and the nanomechanical properties got no change after 1 week of remineralization. As for the 35CP group, the nanotribological properties were influenced and the nanomechanical properties were not

  20. Contrasting patterns of coral bleaching susceptibility in 2010 suggest an adaptive response to thermal stress.

    Directory of Open Access Journals (Sweden)

    James R Guest

    Full Text Available BACKGROUND: Coral bleaching events vary in severity, however, to date, the hierarchy of susceptibility to bleaching among coral taxa has been consistent over a broad geographic range and among bleaching episodes. Here we examine the extent of spatial and temporal variation in thermal tolerance among scleractinian coral taxa and between locations during the 2010 thermally induced, large-scale bleaching event in South East Asia. METHODOLOGY/PRINCIPAL FINDINGS: Surveys to estimate the bleaching and mortality indices of coral genera were carried out at three locations with contrasting thermal and bleaching histories. Despite the magnitude of thermal stress being similar among locations in 2010, there was a remarkable contrast in the patterns of bleaching susceptibility. Comparisons of bleaching susceptibility within coral taxa and among locations revealed no significant differences between locations with similar thermal histories, but significant differences between locations with contrasting thermal histories (Friedman = 34.97; p<0.001. Bleaching was much less severe at locations that bleached during 1998, that had greater historical temperature variability and lower rates of warming. Remarkably, Acropora and Pocillopora, taxa that are typically highly susceptible, although among the most susceptible in Pulau Weh (Sumatra, Indonesia where respectively, 94% and 87% of colonies died, were among the least susceptible in Singapore, where only 5% and 12% of colonies died. CONCLUSIONS/SIGNIFICANCE: The pattern of susceptibility among coral genera documented here is unprecedented. A parsimonious explanation for these results is that coral populations that bleached during the last major warming event in 1998 have adapted and/or acclimatised to thermal stress. These data also lend support to the hypothesis that corals in regions subject to more variable temperature regimes are more resistant to thermal stress than those in less variable environments.

  1. Evaluation of the bleached human enamel by Scanning Electron Microscopy

    DEFF Research Database (Denmark)

    Miranda, Carolina Baptista; Pagani, Clovis; Benetti, Ana Raquel

    2005-01-01

    Electron Microscopy (SEM). Materials and Methods: Twenty intact human third molars extracted for orthodontic reasons were randomly divided into four groups (n=5) treated as follows: G1- storage in artificial saliva (control group); G2- four 30-minute applications of 35% carbamide peroxide (total exposure...... analysis performing gold sputter coating under vacuum and were examined using 15kV at 500x and 2000x magnification. Results: Morphological alterations on the enamel surface were similarly detected after bleaching with either 35% carbamide peroxide or 35% hydrogen peroxide. Surface porosities were...

  2. Beneficial Reuse of San Ardo Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Robert A. Liske

    2006-07-31

    This DOE funded study was performed to evaluate the potential for treatment and beneficial reuse of produced water from the San Ardo oilfield in Monterey County, CA. The potential benefits of a successful full-scale implementation of this project include improvements in oil production efficiency and additional recoverable oil reserves as well as the addition of a new reclaimed water resource. The overall project was conducted in two Phases. Phase I identified and evaluated potential end uses for the treated produced water, established treated water quality objectives, reviewed regulations related to treatment, transport, storage and use of the treated produced water, and investigated various water treatment technology options. Phase II involved the construction and operation of a small-scale water treatment pilot facility to evaluate the process's performance on produced water from the San Ardo oilfield. Cost estimates for a potential full-scale facility were also developed. Potential end uses identified for the treated water include (1) agricultural use near the oilfield, (2) use by Monterey County Water Resources Agency (MCWRA) for the Salinas Valley Water Project or Castroville Seawater Intrusion Project, (3) industrial or power plant use in King City, and (4) use for wetlands creation in the Salinas Basin. All of these uses were found to have major obstacles that prevent full-scale implementation. An additional option for potential reuse of the treated produced water was subsequently identified. That option involves using the treated produced water to recharge groundwater in the vicinity of the oil field. The recharge option may avoid the limitations that the other reuse options face. The water treatment pilot process utilized: (1) warm precipitation softening to remove hardness and silica, (2) evaporative cooling to meet downstream temperature limitations and facilitate removal of ammonia, and (3) reverse osmosis (RO) for removal of dissolved salts, boron

  3. Bleaching augments lipid peroxidation products in pistachio oil and its cytotoxicity

    Science.gov (United States)

    Pistachio consumption is associated with reductions in serum cholesterol and oxidative stress due to their constituents of unsaturated fats, phytosterols, fiber, and antioxidants. Bleaching has been applied to whiten nut shells for antifungal and cosmetic purposes. However, the impact of bleaching o...

  4. Skin bleaching: A neglected form of injury and threat to global skin ...

    African Journals Online (AJOL)

    Skin bleaching: A neglected form of injury and threat to global skin. JC Street, K Gaska, KM Lewis, ML Wilson. Abstract. Skin bleaching is the use of creams, gels, or soaps to lighten the skin and is known to cause a number of injuries, many of which are potentially life-threatening. Despite the growing body of research ...

  5. Re-evaluating luminescence burial doses and bleaching of fluvial deposits using Bayesian computational statistics.

    NARCIS (Netherlands)

    Cunningham, A.C.; Wallinga, J.; Versendaal, Alice; Makaske, A.; Middelkoop, H.; Hobo, N.

    2015-01-01

    The optically stimulated luminescence (OSL) signal from fluvial sediment often contains a remnant from the previous deposition cycle, leading to a partially bleached equivalent-dose distribution. Although identification of the burial dose is of primary concern, the degree of bleaching could

  6. Re-evaluating luminescence burial doses and bleaching of fluvial deposits using Bayesian computational statistics

    NARCIS (Netherlands)

    Cunningham, A. C.; Wallinga, J.; Hobo, N.; Versendaal, A. J.; Makaske, B.; Middelkoop, H.

    2015-01-01

    The optically stimulated luminescence (OSL) signal from fluvial sediment often contains a remnant from the previous deposition cycle, leading to a partially bleached equivalent-dose distribution. Although identification of the burial dose is of primary concern, the degree of bleaching could

  7. WOOD BASIC DENSITY EFFECT OF Eucalyptus grandis x Eucalyptus urophylla CLONES ON BLEACHED PULP QUALITY

    Directory of Open Access Journals (Sweden)

    Sheila Rodrigues dos Santos

    2010-08-01

    Full Text Available The study analyzed the wood basic density effect in two Eucalyptus grandis x Eucalyptus urophylla hybrid clones (440 kg/m3 e 508 kg/m3 on bleached pulp quality (fiber dimensions and physical-mechanical properties. The woods performance on pulping, bleaching and beating results were analyzed. The Kraft pulping was carried out in forced circulation digester in order to obtain 17±1 kappa number targets. The pulps were bleached to 90±1 using delignification oxygen and D0EOPD1 bleaching sequence. Bleached pulp of low basic density clone showed, significantly, lowest revolutions number in the PFI mill to reach tensile index of 70 N.m/g, low Schopper Riegler degree and generated sheets with higher values to bulk and opacity. These characteristics and properties allow concluding that bleached pulp of low basic density clone was the most indicated to produce printing and writing sheets. The bleached pulp of high basic density clone showed higher values of bulk and capillarity Klemm and lower water retention value when analyzed without beating. The bleached pulp of high basic density clone showed more favorable characteristics to the production of tissue papers.

  8. Influence of photo- and thermal bleaching on pre-irradiation low water peak single mode fibers

    Science.gov (United States)

    Yin, Jianchong; Wen, Jianxiang; Luo, Wenyun; Xiao, Zhongyin; Chen, Zhenyi; Wang, Tingyun

    2011-12-01

    Reducing the radiation-induced transmission loss in low water peak single mode fiber (LWP SMF) has been investigated by using photo-bleaching method with 980nm pump light source and using thermal-bleaching method with temperature control system. The results show that the radiation-induced loss of pre-irradiation optical fiber can be reduced effectively with the help of photo-bleaching or thermal-bleaching. Although the effort of photo-bleaching is not as significant as thermal-bleaching, by using photo-bleaching method, the loss of fiber caused by radiation-induced defects can be reduced best up to 49% at 1310nm and 28% at 1550nm in low pre-irradiation condition, the coating of the fiber are not destroyed, and the rehabilitating time is just several hours, while self-annealing usually costs months' time. What's more, the typical high power LASER for photo-bleaching can be 980nm pump Laser Diode, which is very accessible.

  9. Remote Sensing of Coral Bleaching Using Temperature and Light: Progress towards an Operational Algorithm

    Directory of Open Access Journals (Sweden)

    William Skirving

    2017-12-01

    Full Text Available The National Oceanic and Atmospheric Administration’s Coral Reef Watch program developed and operates several global satellite products to monitor bleaching-level heat stress. While these products have a proven ability to predict the onset of most mass coral bleaching events, they occasionally miss events; inaccurately predict the severity of some mass coral bleaching events; or report false alarms. These products are based solely on temperature and yet coral bleaching is known to result from both temperature and light stress. This study presents a novel methodology (still under development, which combines temperature and light into a single measure of stress to predict the onset and severity of mass coral bleaching. We describe here the biological basis of the Light Stress Damage (LSD algorithm under development. Then by using empirical relationships derived in separate experiments conducted in mesocosm facilities in the Mexican Caribbean we parameterize the LSD algorithm and demonstrate that it is able to describe three past bleaching events from the Great Barrier Reef (GBR. For this limited example, the LSD algorithm was able to better predict differences in the severity of the three past GBR bleaching events, quantifying the contribution of light to reduce or exacerbate the impact of heat stress. The new Light Stress Damage algorithm we present here is potentially a significant step forward in the evolution of satellite-based bleaching products.

  10. Severity of the 1998 and 2005 bleaching events in Venezuela, southern Caribbean

    Directory of Open Access Journals (Sweden)

    Sebastián Rodríguez

    2010-10-01

    Full Text Available This study describes the severity of the 2005 bleaching event at 15 reef sites across Venezuela and compares the 1998 and 2005 bleaching events at one of them. During August and September 2005, bleached corals were first observed on oceanic reefs rather than coastal reefs, affecting 1 to 4% of coral colonies in the community (3 reef sites, n=736 colonies. At that time, however, no bleached corals were recorded along the eastern coast of Venezuela, an area of seasonal upwelling (3 reefs, n=181 colonies. On coastal reefs, bleaching started in October but highest levels were reached in November 2005 and January 2006, when 16% of corals were affected among a wide range of taxa (e.g. scleractinians, octocorals, Millepora and zoanthids. In the Acropora habitats of Los Roques (an oceanic reef, no bleached was recorded in 2005 (four sites, n=643 colonies. At Cayo Sombrero, a coastal reef site, bleaching was less severe in 1998 than in 2005 (9% of the coral colonies involving 2 species vs. 26% involving 23 species, respectively. Our results indicate that bleaching was more severe in 2005 than in 1998 on Venezuelan reefs; however, no mass mortality was observed in either of these two events. Rev. Biol. Trop. 58 (Suppl. 3: 189-196. Epub 2010 October 01.

  11. Severity of the 1998 and 2005 bleaching events in Venezuela, southern Caribbean.

    Science.gov (United States)

    Rodríguez, Sebastián; Cróquer, Aldo; Bone, David; Bastidas, Carolina

    2010-10-01

    This study describes the severity of the 2005 bleaching event at 15 reef sites across Venezuela and compares the 1998 and 2005 bleaching events at one of them. During August and September 2005, bleached corals were first observed on oceanic reefs rather than coastal reefs, affecting 1 to 4% of coral colonies in the community (3 reef sites, n = 736 colonies). At that time, however, no bleached corals were recorded along the eastern coast of Venezuela, an area of seasonal upwelling (3 reefs, n = 181 colonies). On coastal reefs, bleaching started in October but highest levels were reached in November 2005 and January 2006, when 16% of corals were affected among a wide range of taxa (e.g. scleractinians, octocorals, Millepora and zoanthids). In the Acropora habitats of Los Roques (an oceanic reef),no bleached was recorded in 2005 (four sites,n = 643 colonies). At Cayo Sombrero, a coastal reef site, bleaching was less severe in 1998 than in 2005 (9% of the coral colonies involving 2 species vs. 26% involving 23 species, respectively). Our results indicate that bleaching was more severe in 2005 than in 1998 on Venezuelan reefs; however, no mass mortality was observed in either of these two events.

  12. [Effect of bleaching agents on the color of indirect and direct composite resins].

    Science.gov (United States)

    Xing, Wenzhong; Jiang, Tao; Chen, Xiaodong; Wang, Yining

    2014-09-01

    To evaluate the effect of bleaching agents on the color of indirect and direct composite resins. Five resin composite materials were tested in this in vitro study. The five composites were as follow: two indirect composite resins (Adoro SR, Ceramage) and three direct composite resins (Filtek Z350, Clearfil Majesty Esthetic, and Gradia Direct Anterior). For each material, twenty disk-shaped specimens were prepared and randomly divided into five groups according to the color parameters of specimens before bleaching treatment. The composite resin specimens were treated by one of five sample solutions which were at-home bleaching agents (10% and 15% carbarmide peroxide), in- office bleaching agents (38% H(2)O(2) and 35%H(2)O(2)) and deionized water (control group). The color parameters of specimens were measured by spectrophotometer at baseline and after bleaching treatments. The color differences (ΔE values) between baseline and post-treatments were calculated. The data of color differences were evaluated statistically using two-way analysis with a significance level of 0.05. The color changes of the resin composites were less than 2.0 after bleaching agent treatment, therefore were not perceptible. Slight increase of L(*) values and decrease of C(*)ab values in color parameters of specimens were observed. There were statistically significant differences in ΔE values for different bleaching treatments and resin materials (P = 0.001). The bleaching agents did not affect the color of indirect and direct composite resins tested.

  13. Comparing Environmental Influences on Coral Bleaching Across and within Species using Clustered Binomial Regression

    Science.gov (United States)

    Differential susceptibility among reef-building coral species can lead to community shifts and loss of diversity as a result of temperature-induced mass bleaching events. However, the influence of the local environment on species-specific bleaching susceptibilities has not been ...

  14. Post-bleaching application of an antioxidant on dentin bond strength of three dental adhesives

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2012-01-01

    Conclusions: The findings suggest that bond strength of resin to bleached dentin may be affected with the adhesive system. Reduced SBS to bleached dentin can be amended by the use of SA as an antioxidizing agent. However, the amount of reversed bond strength subsequent to applying antioxidant might be related to the kind of dental adhesive.

  15. Effect of nightguard vital bleaching gel on the color stability of provisional restorative materials.

    Science.gov (United States)

    Bajunaid, Salwa Omar

    2016-01-01

    To assess the hypothesis that there was no difference in effect of 10% and 15% tooth bleaching agents on color stability of materials used for provisional fixed dental prosthesis. Fifteen samples from two materials used for provisional fixed dental prosthesis: methacrylate-based and composite-based materials and 15 preformed polycarbonate crowns soaked in bleaching gel or distilled water. Spectrophotometer recorded color of specimens at baseline, after 3, 7, and 14 days. Data were statistically analyzed using two-factor ANOVA test to compare the color stability of tested materials. Methyl-based provisional material exhibited statistically higher color change when exposed to 10% and 15% bleaching gel (delta EFNx01: 9.0 and 11.1, respectively) as compared to distilled water (delta EFNx01: 2.9). Delta EFNx01 of composite-based material specimens exposed to distilled water was statistically higher (6.3) than specimens exposed to 10% and 15% bleaching gel (1.5 and 1.1, respectively). Polycarbonate crowns showed a statistically lower color change when exposed to 15% (0.9) than to 10% bleaching gel (5.1) or distilled water (5.5). Composite-based provisional material showed highest color stability when exposed to vital tooth bleaching gel, whereas methacrylate-based material was the least color stable. Polycarbonate crowns were more color stable when exposed to 15% bleaching gel as opposed to 10% bleaching gel.

  16. Assessment of acute phase proteins and oxidative stress status of Nigerians using bleaching agents

    International Nuclear Information System (INIS)

    Akibinu, M.O.; Arinola, O.G.; Afolabi, K.A.

    2010-01-01

    The disruption of primary innate immune function of the epidermal layer of the skin accounts for the susceptibility of individuals using bleaching agents to localized or systemic infections. This subverted innate immunity in these people may lead to other pathological conditions. The resultant effects of skin bleaching and phagocytes activation in response to infections have not been studied in Nigerians using bleaching agents. The present study therefore assessed the levels of C-reactive protein (CRP), albumin, total antioxidant potential (TAP), total plasma peroxides (TPP), oxidative stress index (OSI) and malonaldehyde (MDA) in the users bleaching agents. Thirty (30) people who had used bleaching agents for average of 4.9 + 1.2 years participated in this study. They were recruited from various schools and markets within the city of Ibadan, Oyo State, Nigeria. Thirty apparently healthy staffs of University College Hospital Ibadan, Ibaadan, Nigeria, who had never used bleaching agents served as controls. All the subjects used for this study had no metabolic abnormality and tested negative to both HIV and hepatitis B infections. The mean value of TAP (p 0.20) when compared with the controls. Oxidative stress and chronic inflammation are possible consequences of skin bleaching. The users of skin bleaching agents may need antioxidant therapies to avert the risks of oxidative stress. (author)

  17. Filtration engineering study to upgrade the ETF

    International Nuclear Information System (INIS)

    McDonald, F.N.N.

    1995-01-01

    Filtration technologies are evaluated which have potential to augment or upgrade the 200 Area Effluent Treatment Facility. The study was written in anticipation of treating future waste waters that have high fouling potentials. The Three ultrafilters judged to be capable of treating future waste waters are: hollow fiber, tubular, and centrifugal

  18. Using Digital Filtration for Hurst Parameter Estimation

    Directory of Open Access Journals (Sweden)

    J. Prochaska

    2009-06-01

    Full Text Available We present a new method to estimate the Hurst parameter. The method exploits the form of the autocorrelation function for second-order self-similar processes and is based on one-pass digital filtration. We compare the performance and properties of the new method with that of the most common methods.

  19. Upflow gravel filtration for multiple uses

    NARCIS (Netherlands)

    Sanchez Torres, L.D.

    2016-01-01

    The use of upflow gravel filtration (UFG) is relevant for water supply systems in rural areas and small towns in Colombia, because water quality from surface sources is changing due to the deterioration of watersheds caused by deforestation, erosion, and the discharge of untreated wastewater. These

  20. Filtration aids in uranium ore processing

    International Nuclear Information System (INIS)

    Ford, H.L.; Levine, N.M.; Risdon, A.R.

    1975-01-01

    A process of improving the filtration efficiency and separation of uranium ore pulps obtained by carbonate leaching of uranium ore which comprises treating said ore pulps with an aqueous solution of hydroxyalkyl guar selected from the group consisting of hydroxyethyl and hydroxypropyl guar in the amount of 0.1 and 2.0 pounds of hydroxyalkyl guar per ton of uranium ore

  1. Filtration of engineered nanoparticles using porous membranes

    NARCIS (Netherlands)

    Trzaskus, Krzystof

    2016-01-01

    The research presented in this thesis aims at providing a better understanding of the fundamental aspects responsible for nanoparticle removal and fouling development during filtration of engineered nanoparticles. The emphasis is put on the role of interparticle interactions in the feed solution,

  2. Organic micropollutant removal during river bank filtration

    NARCIS (Netherlands)

    Bertelkamp, C.

    2015-01-01

    This study investigated the factors influencing the main removal mechanisms (adsorption and biodegradation) for organic micropollutant (OMP) removal during river bank filtration (RBF) and the possibility of developing a predictive model of this process for OMP removal during RBF. Chapter 2 analysed

  3. Determination of glomerular filtration rate with radionuclide ...

    African Journals Online (AJOL)

    Mulligan JS, Blue PW, Hasbargen JA. Methods for measuring GFR with technetium-99m-OTPA: an analysis of several common methods. J Nucl Med. 1990; 31: 1211-1219. 4. Jackson JH. Blue PW. Ghaed N. Glomerular filtration rate determined in conjunction with routine renal scanning. Radiology 1985; 154: 203-205. 5.

  4. Solute partitioning and filtration by extracellular matrices

    Science.gov (United States)

    Hofmann, Christina L.; Ferrell, Nicholas; Schnell, Lisa; Dubnisheva, Anna; Zydney, Andrew L.; Yurchenco, Peter D.; Roy, Shuvo

    2009-01-01

    The physiology of glomerular filtration remains mechanistically obscure despite its importance in disease. The correspondence between proteinuria and foot process effacement suggests podocytes as the locus of the filtration barrier. If so, retained macromolecules ought to accumulate at the filtration barrier, an effect called concentration polarization. Literature data indicate macromolecule concentrations decrease from subendothelial to subepithelial glomerular basement membrane (GBM), as would be expected if the GBM were itself the filter. The objective of this study was to obtain insights into the possible role of the GBM in protein retention by performing fundamental experimental and theoretical studies on the properties of three model gels. Solute partitioning and filtration through thin gels of a commercially available laminin-rich extracellular matrix, Matrigel, were measured using a polydisperse polysaccharide tracer molecule, Ficoll 70. Solute partitioning into laminin gels and lens basement membrane (LBM) were measured using Ficoll 70. A novel model of a laminin gel was numerically simulated, as well as a mixed structure-random-fiber model for LBM. Experimental partitioning was predicted by numerical simulations. Sieving coefficients through thin gels of Matrigel were size dependent and strongly flux dependent. The observed flux dependence arose from compression of the gel in response to the applied pressure. Gel compression may alter solute partitioning into extracellular matrix at physiologic pressures present in the glomerular capillary. This suggests a physical mechanism coupling podocyte structure to permeability characteristics of the GBM. PMID:19587146

  5. Advances in hot gas filtration technology

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.

    The past decade has seen the introduction of new filter media specifically designed for 'hot-gas' filtration. These media are available as woven or knitted fabrics and as non-wovens, i.e. needled felts. Needlefelted fabrics have proven so highly successful in the dedusting of hot gases that they are widely used nowadays in this new and necessary technology. Hot-gas filtration offers advantages in, for example, the saving or recycling of energy, the elimination of the cooling process, and the short-circuiting of process steps. This paper gives a survey of the types of textile fibres available for hot-gas filtration from the more recently developed organic fibres to refractory fibres. It describes, compares and contrasts their salient properties and lists the uses to which they may be put. It concentrates on such fibres which are generally referred to as 'high performance materials', since they are expected to provide satisfactory performance under extreme conditions of temperature, chemical environment and mechanical stress. It touches on filtration theory governing the collection mechanism. 9 refs., 7 figs., 3 tabs.

  6. Water reuse by membrane bioreactors (MBR)

    International Nuclear Information System (INIS)

    Garcia, G.; Huete, E.; Martinez, L. C.; Torres, A.

    2010-01-01

    This paper shows an up-to date overview of the use of membrane bioreactor (MBR) to obtain water treated for reusing it. Considering the existing rules. it has been presented a summary of published studies in which the quality of the effluent is analyzed in terms on physico-chemical and biological parameters. Furthermore, MBR results are compared with the conventional treatment ones. Due to the suitability of MBR technology for removing pathogens, particular attention has been paid to disinfection process and the mechanism that govern it. Results from reviewed studies of MBR have showed equal or better quality of water treated than conventional treatments (activated sludge plus disinfection tertiary treatment by the addition of antibacterial agents). (Author) 32 refs.

  7. Technology for reuse of contaminated concrete constituents

    International Nuclear Information System (INIS)

    Binkhorst, I.P.; Cornelissen, H.A.W.

    1998-01-01

    During decommissioning activities of nuclear installations, large amounts of contaminated concrete will have to be processed. All this concrete has to be treated and stored as radioactive waste, which implies major economical and environmental consequences. It was shown that the contamination is mainly concentrated in the porous cement stone. By separating this cement stone from the clean dense aggregate particles, a considerable volume reduction can be reached. KEMA has developed, designed and constructed a pilot plant scale test installation for separation of aggregate from contaminated concrete. The separation is based on a thermal treatment followed by milling and sieving. The clean aggregate can be re-used in concrete, whereas the (slightly) contaminated cement stone could be upgraded to a binder for concrete used in the nuclear industry. (author)

  8. OAI Object Re-Use and Exchange

    CERN Document Server

    CERN. Geneva; Jacobs, Neil

    2007-01-01

    YouTube, Flickr, del.icio.us, blogs, message boards and other "Web 2.0" related technologies are indicative of the contemporary web experience. There is a growing interest in appropriating these tools and modalities to support the scholarly communication process. This begins with leveraging the intrinsic value of scholarly digital objects beyond the borders of the hosting repository. There are numerous examples of the need to re-use objects across repositories in scholarly communication. These include citation, preservation, virtual collections of distributed objects, and the progression of units of scholarly communication through the registration-certification-awareness-archiving chain. The last several years have brought about numerous open source repository systems and their associated communities. The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) has been the initial catalyst for repository interoperability. However, there is now a rising interest in repositories no longer being stat...

  9. OAI Object Re-Use and Exchange

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    There is a growing interest in appropriating these tools and modalities to support the scholarly communication process. This begins with leveraging the intrinsic value of scholarly digital objects beyond the borders of the hosting repository. There are numerous examples of the need to re-use objects across repositories in scholarly communication. These include citation, preservation, virtual collections of distributed objects, and the progression of units of scholarly communication through the registration-certification-awareness-archiving chain. The last several years have brought about numerous open source repository systems and their associated communities. The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) has been the initial catalyst for repository interoperability. However, there is now a rising interest in repositories no longer bein...

  10. Assessment of Cryptosporidium in wastewater reuse for drinking ...

    African Journals Online (AJOL)

    Wastewater reuse is becoming increasingly important for supplementing drinking water supply needs and/or to reduce costs in many communities around the world. However, wastewater reuse can result in a potential transmission route for infectious agents. Therefore, the occurrence of Cryptosporidium was assessed in a ...

  11. Methods & tools for publishing & reusing linked open statistical data

    NARCIS (Netherlands)

    Tambouris, Efthimios; Kalampokis, Evangelos; Janssen, M.F.W.H.A.; Krimmer, Robert; Tarabanis, Konstantinos

    2017-01-01

    The number of open data available for reuse is rapidly increasing. A large number of these data are numerical thus can be easily visualized. Linked open data technology enables easy reuse and linking of data residing in di.erent locations. In this workshop, we will present a number of

  12. Recycling and reuse of wastewater from uranium mining and milling

    International Nuclear Information System (INIS)

    Xu Lechang; Gao Jie; Zhang Xueli; Wei Guangzhi; Zhang Guopu

    2010-01-01

    Uranium mining/milling process, and the sources, recycling/reuse approach and treatment methods of process wastewater are introduced. The wastewater sources of uranium mining and milling include effluent, raffinate, tailings water, mine discharge, resin form converted solution, and precipitation mother liquor. Wastewater can be recycled/reused for leachant, eluent, stripping solution,washing solution and tailings slurry. (authors)

  13. Effect of Dispersion and Bleaching on the Mechanical and Optical Properties of Deinked Recycled Pulp

    Directory of Open Access Journals (Sweden)

    yahya hamzeh

    2016-06-01

    Full Text Available In this study the effects of oxidative bleaching and mechanical dispersion in different conditions on the optical and mechanical properties of deinked recycled pulp was investigated. Industrial deinked pulp was treated in the different conditions, including dispersion, combined oxidative bleaching during dispersion, and separate dispersion and then oxidative bleaching. Handsheet papers were made from obtained pulps and then scanned and taken photos were analyzed by Digimizer software, version 4.1.1.0 to analysis spot content. Optical and mechanical properties of obtained handsheets were determined and compared. Results indicated that mechanical dispersion decreased spot content and brightness and increased yellowing of the handsheets. Moreover, mechanical dispersion increased dry and wet tensile and burst strengths, water retention value (WRV, ash content and decreased tear strength of handsheet papers. This study revealed that combined dispersing and oxidative bleaching of de-inked pulp provided superior results in comparison to the separate dispersing and oxidative bleaching.

  14. Enamel susceptibility to red wine staining after 35% hydrogen peroxide bleaching

    Directory of Open Access Journals (Sweden)

    Sandrine Bittencourt Berger

    2008-06-01

    Full Text Available Concern has been expressed regarding the staining of enamel surface by different beverages after bleaching. This study investigated the influence of 35% hydrogen peroxide bleaching agents on enamel surface stained with wine after whitening treatments. Flat and polished bovine enamel surfaces were submitted to two commercially available 35% hydrogen peroxide bleaching agents or kept in 100% humidity, as a control group (n = 10. Specimens of all groups were immersed in red wine for 48 h at 37°C, immediately, 24 h or 1 week after treatments. All specimens were ground into powder and prepared for the spectrophotometric analysis. Data were subjected to two-way analysis of variance and Fisher's PLSD test at 5% significance level. The amount of wine pigments uptake by enamel submitted to bleaching treatments was statistically higher than that of control group, independently of the evaluation time. Results suggested that wine staining susceptibility was increased by bleaching treatments.

  15. Spatial and temporal patterns of mass bleaching of corals in the Anthropocene

    KAUST Repository

    Hughes, Terry P.

    2018-01-16

    Tropical reef systems are transitioning to a new era in which the interval between recurrent bouts of coral bleaching is too short for a full recovery of mature assemblages. We analyzed bleaching records at 100 globally distributed reef locations from 1980 to 2016. The median return time between pairs of severe bleaching events has diminished steadily since 1980 and is now only 6 years. As global warming has progressed, tropical sea surface temperatures are warmer now during current La Nina conditions than they were during El Nino events three decades ago. Consequently, as we transition to the Anthropocene, coral bleaching is occurring more frequently in all El Nino-Southern Oscillation phases, increasing the likelihood of annual bleaching in the coming decades.

  16. Climate change disables coral bleaching protection on the Great Barrier Reef.

    Science.gov (United States)

    Ainsworth, Tracy D; Heron, Scott F; Ortiz, Juan Carlos; Mumby, Peter J; Grech, Alana; Ogawa, Daisie; Eakin, C Mark; Leggat, William

    2016-04-15

    Coral bleaching events threaten the sustainability of the Great Barrier Reef (GBR). Here we show that bleaching events of the past three decades have been mitigated by induced thermal tolerance of reef-building corals, and this protective mechanism is likely to be lost under near-future climate change scenarios. We show that 75% of past thermal stress events have been characterized by a temperature trajectory that subjects corals to a protective, sub-bleaching stress, before reaching temperatures that cause bleaching. Such conditions confer thermal tolerance, decreasing coral cell mortality and symbiont loss during bleaching by over 50%. We find that near-future increases in local temperature of as little as 0.5°C result in this protective mechanism being lost, which may increase the rate of degradation of the GBR. Copyright © 2016, American Association for the Advancement of Science.

  17. Seasonal Dynamical Prediction of Coral Bleaching in the Great Barrier Reef, Australia

    Science.gov (United States)

    Spillman, C. M.; Alves, O.

    2009-05-01

    Sea surface temperature (SST) is now recognised as the primary cause of mass coral bleaching events. Coral bleaching occurs during times of stress, particularly when SSTs exceed the coral colony's tolerance level. Global warming is potentially a serious threat to the future of the world's reef systems with predictions by the international community that bleaching will increase in both frequency and severity. Advance warning of anomalous sea surface temperatures, and thus potential bleaching events, would allow for the implementation of management strategies to minimise reef damage. Seasonal SST forecasts from the coupled ocean-atmosphere model POAMA (Bureau of Meteorology) have skill in the Great Barrier Reef (Australia) several months into the future. We will present model forecasts and probabilistic products for use in reef management, and assess model skill in the region. These products will revolutionise the way in which coral bleaching events are monitored and assessed in the Great Barrier Reef and Australian region.

  18. The combination of sodium perborate and water as intracoronal teeth bleaching agent

    Directory of Open Access Journals (Sweden)

    Ananta Tantri Budi

    2008-12-01

    Full Text Available Background: The color change on post-endodontic treated teeth can be overcome by intracoronal tooth bleaching using walking bleach. Some agents used in walking bleach are combination of sodium peroxide and hydrogen peroxide, and combination of sodium perborate and water. Purpose: The objective of this review is to provide information and consideration of using safe and effective bleaching agents in the field of dentistry. Reviews: On one side, the use of sodium perborate and water combination does not cause the reduction of dentin hardness, enamel decay, and root resorbtion. On the other side, the use of sodium perborate and 30% hydrogen peroxide combination indicates that it takes longer time in yielding the proper color of teeth. Conclusion: The use of sodium perborate and water combination as bleaching agents is effective and safe.

  19. Dataset on the spent filter backwash water treatment by sedimentation, coagulation and ultra filtration.

    Science.gov (United States)

    Mahdavi, Mokhtar; Ebrahimi, Afshin; Azarpira, Hossein; Tashauoei, Hamid Reza; Mahvi, Amir Hossein

    2017-12-01

    During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2-10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW through different method including pre-sedimentation, coagulation and flocculation, second clarification, ultra filtration (UF) and returned settled SFBW to the beginning of water treatment plant (WTP). Also, two coagulants of polyaluminum ferric chloride (PAFCl) and ferric chloride (FeCl 3 ) were investigated with respect to their performance on treated SFBW quality. Samples were collected from Isfahan's WTP in Iran during spring and summer season. The acquired data indicated that drinkable water can be produced form SFBW by applying hybrid coagulation-UF process (especially when PAFCl used as coagulant).

  20. Effects of hydrogen peroxide bleaching strip gels on dental restorative materials in vitro: surface microhardness and surface morphology.

    Science.gov (United States)

    Duschner, Heinz; Götz, Hermann; White, Donald J; Kozak, Kathleen M; Zoladz, James R

    2004-01-01

    This study examined the effects of peroxide tooth bleaching, including Crest Whitestrips hydrogen peroxide gel treatments, on the surface hardness and morphology of common dental restorative treatments. American Dental Association (ADA) recommended dental restorative materials, including amalgam, dental gold, porcelain, glass ionomer, and composites, were prepared according to manufacturers' instructions. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching gels, which utilize hydrogen peroxide as the in situ bleaching source, and several commercial carbamide peroxide bleaching gels. Control treatments included placebo gels and an untreated group. Crest Whitestrips bleaching included treatment exposures simulating recommended clinical exposures (14 hours), along with excess bleaching simulating exposure to five times suggested Crest Whitestrips use. At the conclusion of treatments, surface microhardness measures and surface morphological assessments with standard and variable pressure (VP-) SEMs were conducted to assess the effects of bleaching exposure on the surface morphology and structural integrity of the restoratives. Surface microhardness and SEM measures revealed no significant deleterious effects on the restoration surfaces from Whitestrips gels. These results confirm that tooth bleaching from the selected commercial hydrogen peroxide or carbamide peroxide bleaching systems does not produce changes in surface morphology or microhardness of common dental restorative materials. These results support the clinical safety of the selected commercial bleaching systems to the oral environment, matching results obtained from long-term use of these ingredients applied in dental offices and available in commercial formulations.

  1. Influence of Bleaching on Flavor of 34% Whey Protein Concentrate and Residual Benzoic Acid Concentration in Dried Whey Proteins

    Science.gov (United States)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  2. Influence of bleaching on flavor of 34% whey protein concentrate and residual benzoic acid concentration in dried whey products

    Science.gov (United States)

    Previous studies have shown that bleaching negatively affects the flavor of 70% whey protein concentrate (WPC70), but bleaching effects on lower-protein products have not been established. Benzoyl peroxide (BP), a whey bleaching agent, degrades to benzoic acid (BA) and may elevate BA concentrations...

  3. Bleaching of leaf litter and associated microfungi in subboreal and subalpine forests.

    Science.gov (United States)

    Hagiwara, Yusuke; Matsuoka, Shunsuke; Hobara, Satoru; Mori, Akira S; Hirose, Dai; Osono, Takashi

    2015-10-01

    Fungal decomposition of lignin leads to the whitening, or bleaching, of leaf litter, especially in temperate and tropical forests, but less is known about such bleaching in forests of cooler regions, such as boreal and subalpine forests. The purposes of the present study were to examine the extent of bleached area on the surface of leaf litter and its variation with environmental conditions in subboreal and subalpine forests in Japan and to examine the microfungi associated with the bleaching of leaf litter by isolating fungi from the bleached portions of the litter. Bleached area accounted for 21.7%-32.7% and 2.0%-10.0% of total leaf area of Quercus crispula and Betula ermanii, respectively, in subboreal forests, and for 6.3% and 18.6% of total leaf area of B. ermanii and Picea jezoensis var. hondoensis, respectively, in a subalpine forest. In subboreal forests, elevation, C/N ratio and pH of the FH layer, and slope aspect were selected as predictor variables for the bleached leaf area. Leaf mass per area and lignin content were consistently lower in the bleached area than in the nonbleached area of the same leaves, indicating that the selective decomposition of acid unhydrolyzable residue (recalcitrant compounds such as lignin, tannins, and cutins) enhanced the mass loss of leaf tissues in the bleached portions. Isolates of a total of 11 fungal species (6 species of Ascomycota and 5 of Basidiomycota) exhibited leaf-litter-bleaching activity under pure culture conditions. Two fungal species (Coccomyces sp. and Mycena sp.) occurred in both subboreal and subalpine forests, which were separated from each other by approximately 1100 km.

  4. Fracture resistance of endodontically-treated teeth: effect of combination bleaching and an antioxidant.

    Science.gov (United States)

    Khoroushi, Maryam; Feiz, Atieh; Khodamoradi, Roghayeh

    2010-01-01

    This in vitro study assessed the fracture resistance of endodontically-treated teeth undergoing combination bleaching with 38% and 9.5% hydrogen peroxide gels as in-office and at-home bleaching techniques, respectively. In addition, the effect of an antioxidizing agent, sodium ascorbate, was investigated. Sixty maxillary premolars were endodontically-treated, received a glass ionomer barrier as a mechanical seal and were embedded in acrylic resin up to the cemento-enamel junction. The specimens were divided into four groups (n = 15) as follows: G I: no bleaching, access cavity restored with resin composite (negative control); G II: bleached for three weeks daily using 9.5% hydrogen peroxide for two hours and three sessions of in-office bleaching using 38% hydrogen peroxide every seven days, then restored (positive control); G III: bleached similar to G II and restored after one week; G IV: bleached similar to G II, along with the use of an antioxidizing agent for 24 hours, then restored. In each in-office and at-home bleaching session, the whitening gels were applied to the buccal surface of the tooth and placed inside the pulp chamber (inside/outside bleaching technique). Finally, the specimens underwent fracture resistance testing; the data were analyzed using ANOVA and Scheffé's test (alpha = 0.05). Significant differences were observed among the study groups (p 0.05). Within the limitations of the current study, it can be concluded that the fracture resistance of endodontically-treated teeth decreases after combination bleaching. The use of sodium ascorbate can reverse decreased fracture resistance.

  5. Retention of Acholeplasma laidlawii by sterile filtration membranes: effect of cultivation medium and filtration temperature.

    Science.gov (United States)

    Helling, Alexander; König, Hannes; Seiler, Felix; Berkholz, Ralph; Thom, Volkmar; Polakovic, Milan

    2018-01-17

    This experimental study compares cell size, zeta potential and the ability to penetrate tailor-made size exclusion membrane filters of mycoplasma A. laidlawii cultivated in five different cultivation media. The influence of relevant filtration process parameters, in particular transmembrane pressure and filtration temperature, on their respective retention was tested. The impact of the filtration temperature was further evaluated for the Gram-negative bacteria species Brevundimonas diminuta, the Gram-positive bacteria species Staphylococcus epidermidis, the Pseudomonas phage PP7 and the mycoplasma species M. orale. The findings were correlated to the different mechanical properties of the particles, especially also with respect to the different bacterial cell envelopes found in those species. This study suggests, that mycoplasma, surrounded by a flexible lipid bilayer, are significantly susceptible to changes in temperature, altering the stiffness of the cell envelope. Mycoplasma retention could thus be increased significantly by a decreased filtration temperature. In contrast, Gram-negative and Gram-positive bacteria species, with a cell wall containing a cross-linked peptidoglycan layer, as well as bacteriophages PP7 exhibiting a rigid protein capsid, did not show a temperature dependent retention within the applied filtration temperatures between 2 and 35 °C. The trends of the retention of A. laidlawii with increasing temperature and transmembrane pressure were independent of cultivation media. Data obtained with mycoplasma M. orale suggest that the trend of mycoplasma retention at different filtration temperatures is also independent of the membrane pore size and thus retention level. Copyright © 2018, Parenteral Drug Association.

  6. OPTIMIZATION OF THE PROCESS OF DRYING THE FILTRATE DISTILLERY DREGS

    Directory of Open Access Journals (Sweden)

    A. A. Shevtsov

    2013-01-01

    Full Text Available The interactions of various factors affecting the process of drying the filtrate distillery dregs are investigated. Rational conditions for the process of drying the filtrate distillery dregs in a spray dryer are obtained.

  7. Different light-activated in-office bleaching systems: a clinical evaluation.

    Science.gov (United States)

    Gurgan, Sevil; Cakir, Filiz Yalcin; Yazici, Esra

    2010-11-01

    The aim of this clinical study was to evaluate the efficiency of in-office bleaching systems with different light sources for color change and possible side effects such as tooth sensitivity and gingival irritations. Forty healthy volunteers aged 18 years and older (average age 27.3 years), having all their natural healthy teeth in shade A3 or darker on the Vita shade guide, with no restorations on the buccal surfaces and no tooth sensitivity, participated in this study. Participants were randomly assigned to four groups of ten volunteers. Group 1 received bleaching without light activation (Opalescence Xtra Boost, Ultradent); group 2 received bleaching (Laser White 10, Biolase) with a diode laser (810 nm, 10 W/ Laser Smile, Biolase) activation; group 3 received bleaching treatment (Remewhite, Remedent) with a plasma arc lamp (400-490 nm, 2800 mV/cm(2), Remecure CL15), and group 4 received bleaching with a light emitting diode (LED) lamp (By White accelerator, Ensodent) according to the manufacturers' recommendations. The shade was assessed with a classical Vita shade guide (Vita Zahnfabrik) and a digital spectrophotometer (Vita Easy Shade, Vident). The color of teeth was scored at baseline and 1 week after bleaching. Any side effects on teeth or gingiva was recorded by visual analog scale. Results were analyzed statistically, by one-way analysis of variance (ANOVA), Kruskal-Wallis, and Mann-Whitney U tests with Bonferroni correction. All the bleaching techniques resulted in shade change. No significant differences were found in the color change among the four groups with shade guide assessment (P > 0.05), but spectrophotometer readings exhibited significant differences among the groups (P < 0.05). The overall shade change values expressed as DeltaL, Deltaa, Deltab, DeltaE for group 2 was significantly higher than those for the other groups (P < 0.05). Group 2 also showed lower tooth and gingival sensitivity scores than those of the other groups (P < 0.05). All

  8. Simplified method of radionuclide determination of glomerular filtration

    International Nuclear Information System (INIS)

    Butsev, Yu.A.

    1991-01-01

    Glomerular filtration is one of the chief components of renal function. The biochemical methods of its determination (clearance of insulin and endogeneous creatinine) have a number of shortcomings. The use of labelled glomerulotropic agents simplifies methods of the determination of glomerular filtration. A formula and a table of a glomerular filtration value per 1 kg of body mass were calculated

  9. Determination of chromate ion in drilling mud filtrates

    International Nuclear Information System (INIS)

    Whitfill, D.

    1980-01-01

    A method of determining the amount of chromate ion in an aqueous drilling mud filtrate containing organic color bodies such as lignosulfate wherein the method comprises: (A) treating the aqueous filtrate with an effective amount of hydrogen peroxide to destroy said color bodies, and (B) measuring the amount of chromate ion in the filtrate by means of a spectrophotometer

  10. 21 CFR 177.2910 - Ultra-filtration membranes.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ultra-filtration membranes. 177.2910 Section 177... Components of Articles Intended for Repeated Use § 177.2910 Ultra-filtration membranes. Ultra-filtration membranes identified in paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this section may be safely used in...

  11. Cytotoxity of cell free filtrates of campylobacter jejuni isolated in ...

    African Journals Online (AJOL)

    Culture filtrates of Campylobacter jejuni strains isolated from clinical specimens in Lagos Nigeria were tested for toxic activity. Two out of five filtrates tested manifested cytopathic effect on BHK cells. The effects were mainly cytotoxic and cytotonic. Toxic activity of C. jejuni filtrates was much lower than toxic activity elicited by ...

  12. [Public awareness assessment of water reuse in Beijing].

    Science.gov (United States)

    Zhang, Wei-Ling; Chen, Wei-Ping; Jiao, Wen-Tao

    2012-12-01

    Reusing reclaimed municipal wastewater to mitigate urban water shortage is gaining widespread attentions. Beijing has led the nation in implementation and close to 60% of the treated municipal wastewater effluent is being reused. We evaluated the public's awareness of water reuse practices throughout the city. Based on questionnaire and the SPSS software, we analyzed the people's knowledge on water, wastewater and reclaimed issues and willingness to use reclaimed water along with their socio-economical background. While the public was keenly aware of the severe water shortage and the need to treat wastewater, they did not have clear ideas on sources of water supply, the biggest users of water, and the largest contributor of municipal wastewater. Results show that the majority of the Beijing residents we surveyed were not cognizant of water reuses taken places throughout the city. Greater than 80% of the residents would accept reclaimed wastewater for reuses even for domestic usages as long as not related to drinking and food preparation. However, 63% of them would reject reusing it to supplement the public water supply. In general, subjects at a higher education level, with higher personal income, and between ages of 35 to 55 tended to be more supportive of the water reuses. The gender did not significantly affect the outcome of the survey. To enhance the awareness of the city residents, it suggests forwarding the propaganda and management, strengthening the policy-oriented and facility support from the public, community and government.

  13. The cell biology of renal filtration

    Science.gov (United States)

    Quaggin, Susan E.

    2015-01-01

    The function of the kidney, filtering blood and concentrating metabolic waste into urine, takes place in an intricate and functionally elegant structure called the renal glomerulus. Normal glomerular function retains circulating cells and valuable macromolecular components of plasma in blood, resulting in urine with just trace amounts of proteins. Endothelial cells of glomerular capillaries, the podocytes wrapped around them, and the fused extracellular matrix these cells form altogether comprise the glomerular filtration barrier, a dynamic and highly selective filter that sieves on the basis of molecular size and electrical charge. Current understanding of the structural organization and the cellular and molecular basis of renal filtration draws from studies of human glomerular diseases and animal models of glomerular dysfunction. PMID:25918223

  14. Generalized Darcy's Law in Filtration Theory

    Science.gov (United States)

    Rybakov, Yuri P.; Semenova, Natalya V.

    2018-02-01

    We study the hydrodynamics of flow in a porous medium modeling the grain filling in filters. Using the lattice approximation, we derive the structure of the current in porous media and obtain the transverse diffusion coefficient D which proves to be proportional to the diameter d of the grains as constituents of the medium. We consider the axially-symmetric stationary flow in a cylindrical filter and show that the vertical velocity takes its maximal value at the wall, this effect being known as the "near-wall" one. We analyze the solution to the Euler equation with the modified Darcy force, which depends not only on the velocity but also on the gradient of the pressure included in the Darcy coefficient. Finally, within the scope of the perturbation method, we derive the main filtration equation and discuss the influence of modifying the Darcy's law on the efficiency of the filtration process.

  15. Leukocyte removal filtration of platelet concentrates

    International Nuclear Information System (INIS)

    Wadenvik, H.; Kutti, J.; Lindholm, A.

    1991-01-01

    111 In labelled platelets and gamma camera scintigraphy were used for the study of the platelet loss during leukocyte removal filtration of stored platelets. Two different filters were examined, Imugard IG500 and Pall PL100, and platelet pools containing varying number of platelet concentrates were filtered. It was found that a sizeable amount of the platelets was trapped within the filter. Some of the trapped platelets could be recovered by rinsing the filters with normal saline. The most appropriate rinsing volume to recover lost platelets seemed to match with the ''dead space'' volume within the filter. It is concluded that radiolabelled platelets and gamma camera scintigraphy appears to be an excellent method to investigate the dynamic events of platelet loss during leukocyte removal filtration. This technique should be well applicable for the study of technological advances in filter construction. (author)

  16. High Temperature Particle Filtration Technology; TOPICAL

    International Nuclear Information System (INIS)

    Besmann, T.M.

    2001-01-01

    High temperature filtration can serve to improve the economic, environmental, and energy performance of chemical processes. This project was designed to evaluate the stability of filtration materials in the environments of the production of dimethyldichlorosilane (DDS). In cooperation with Dow Corning, chemical environments for the fluidized bed reactor where silicon is converted to DDS and the incinerator where vents are cornbusted were characterized. At Oak Ridge National Laboratory (ORNL) an exposure system was developed that could simulate these two environments. Filter samples obtained from third parties were exposed to the environments for periods up to 1000 hours. Mechanical properties before and after exposure were determined by burst-testing rings of filter material. The results indicated that several types of filter materials would likely perform well in the fluid bed environment, and two materials would be good candidates for the incinerator environment

  17. Enlargement of filtration with finance in view

    CERN Document Server

    Aksamit, Anna

    2017-01-01

    This volume presents classical results of the theory of enlargement of filtration. The focus is on the behavior of martingales with respect to the enlarged filtration and related objects. The study is conducted in various contexts including immersion, progressive enlargement with a random time and initial enlargement with a random variable.  The aim of this book is to collect the main mathematical results (with proofs) previously spread among numerous papers, great part of which is only available in French. Many examples and applications to finance, in particular to credit risk modelling and the study of asymmetric information, are provided to illustrate the theory. A detailed summary of further connections and applications is given in bibliographic notes which enables to deepen study of the topic.  This book fills a gap in the literature and serves as a guide for graduate students and researchers interested in the role of information in financial mathematics and in econometric science. A basic knowledge of...

  18. Air filtration and indoor air quality

    DEFF Research Database (Denmark)

    Bekö, Gabriel

    2006-01-01

    Demands for better indoor air quality are increasing, since we spend most of our time indoors and we are more and more aware of indoor air pollution. Field studies in different parts of the world have documented that high percentage of occupants in many offices and buildings find the indoor air...... decent ventilation and air cleaning/air filtration, high indoor air quality cannot be accomplished. The need for effective air filtration has increased with increasing evidence on the hazardous effects of fine particles. Moreover, the air contains gaseous pollutants, removal of which requires various air...... cleaning techniques. Supply air filter is one of the key components in the ventilation system. Studies have shown that used ventilation filters themselves can be a significant source of indoor air pollution with consequent impact on perceived air quality, sick building syndrome symptoms and performance...

  19. Osmosis, filtration and fracture of porous media

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2001-01-01

    Filtration was produced in a small scale physical model of a granular porous medium of cylindrical shape.The same volume flow was obtained either applying a difference in hydrostatic pressure or in osmotic pressure.In the first case a process of sustained erosion ending in an hydraulic short circuit was observed,while in the second case the material remained stable.This paradoxical strength behaviour is explained using some results from differential geometry,classical field theory and thermo-kinetic theory.The fracture process of a continuous matrix in a porous medium under the combined effect of filtration and external mechanical loads in then considered.The obtained results can be applied to the textural and compressive strength of wet concrete

  20. System-Level Reuse of Space Systems Simulations

    Science.gov (United States)

    Hazen, Michael R.; Williams, Joseph C.

    2004-01-01

    One of the best ways to enhance space systems simulation fidelity is to leverage off of (reuse) existing high-fidelity simulations. But what happens when the model you would like to reuse is in a different coding language or other barriers arise that make one want to just start over with a clean sheet of paper? Three diverse system-level simulation reuse case studies are described based on experience to date in the development of NASA's Space Station Training Facility (SSTF) at the Johnson Space Center in Houston, Texas. Case studies include (a) the Boeing/Rocketdyne-provided Electrical Power Simulation (EPSIM), (b) the NASA Automation and Robotics Division-provided TRICK robotics systems model, and (c) the Russian Space Agency- provided Russian Segment Trainer. In each case, there was an initial tendency to dismiss simulation reuse candidates based on an apparent lack of suitability. A more careful examination based on a more structured assessment of architectural and requirements-oriented representations of the reuse candidates revealed significant reuse potential. Specific steps used to conduct the detailed assessments are discussed. The steps include the following: 1) Identifying reuse candidates; 2) Requirements compatibility assessment; 3) Maturity assessment; 4) Life-cycle cost determination; and 5) Risk assessment. Observations and conclusions are presented related to the real cost of system-level simulation component reuse. Finally, lessons learned that relate to maximizing the benefits of space systems simulation reuse are shared. These concepts should be directly applicable for use in the development of space systems simulations in the future.

  1. Processing of let-down by filtration

    Energy Technology Data Exchange (ETDEWEB)

    Pfirrmann, T.

    1942-10-19

    Filtration used for complete separation of the solids in the let-down process is discussed. The conditions necessary for a filterable let-down were summarized as follows. Pasting with a middle oil rich in aromatics, limitation of the hydrogen consumption and consequent hydrogenation (producing a largely bituminous hydrogenation product), a low throughput at low and medium pressures, and a heavy oil return as low as possible. This applied to pressure up to about 450 atm. If the pressure was increased to 700 atm the operating conditions could be extended. The middle oil pasting remained the same, but the hydrogenation temperature could be increased to 470 to 480/sup 0/C and the throughput increased to 1.0 ton/m/sup 3/ converter vol/hr. The hydrogen consumption could also be increased, so that, besides the bituminous hydrogenation product, a greater proportion of liquid products, gasoline and middle oil, was produced. This operating method at 700 atm, therefore, represented an intermediate stage between hydrogenating extraction and normal hydrogenation, whose let-down was still practically unfilterable. (The filtration itself was fitted to the characteristics of the filter feed). The best type of filter was found to be a thin layer filter with a layer of filter aid of porous material, which was automatically removed with the filter residue. The filter residue contained 35 to 40% oil, largely easily distilled middle oil. The advantages of let-down processing by filtration, compared to the formerly usual methods of centrifuging and low-temperature carbonization, were mentioned. It was to be expected that with the future development of this operation the proportion of oil could be considerably increased, so that filtration might also be applied to fuel oil, or gasoline and middle oil, respectively, even with a modified operating method.

  2. Removal of Inclusions from Aluminum Through Filtration

    Science.gov (United States)

    Damoah, Lucas Nana Wiredu; Zhang, Lifeng

    2010-08-01

    Filtration experiments were carried out using both an AlF3 slurry-coated and an uncoated Al2O3 ceramic foam filter to study the removal of nonmetallic inclusions and impurity elements. The results showed that the 30-ppi ceramic foam filter removed up to 85 pct inclusions from aluminum. Several pictures of two- and three-dimensional morphologies of both nonmetallic and intermetallics inclusions also have been presented. The following contributing mechanisms for the removal of nonmetallic inclusions in the deep-bed filtration mode are proposed: (1) collision with walls and interception effect and (2) the formation of both intermetallic and nonmetallic inclusion bridges during filtration. Fluid dynamics modeling of inclusion attachment to the filter walls showed that most inclusions, especially those with larger sizes, are entrapped at the upper part of the filter, whereas smaller inclusions are dispersed well throughout the filter. The calculated inclusions removal fractions for the 30-ppi filter showed that almost all inclusions >125 μm are removed, and inclusions ~5 μm in size are removed up to 85 pct. The interfacial energy between two collided same-size inclusions was calculated, indicating that a strong clustering of inclusions may result within the filter window. Magnesium impurities were removed up to 86 pct by the AlF3 slurry-coated filter. The filter acted in active filtration mode in addition to the contribution of the air oxidation of dissolved [Mg], which was calculated to be 13 pct. The total mass transfer coefficient of dissolved [Mg] to the reaction interface was calculated to be 1.15 × 10-6 m/s.

  3. Air filtration enhancement using electronic techniques

    International Nuclear Information System (INIS)

    Nelson, G.O.; Richards, C.P.; Biermann, A.H.; Taylor, R.D.; Miller, H.H.

    1976-01-01

    Dielectrophoretic filtration experiments were conducted on glass, polyester, dacron, Teflon, wool, acrylic and polypropylene filter media. A polydispersed (sigma g = 2.0, ammd = 0.95 μ m) sodium chloride particle was used as a test aerosol. All materials exhibited significant increases in efficiency with increasing field strengths. Efficiencies of greater than 99 percent could be obtained from glass fiber mats using a 13 kV/cm electric field at 16.3 cm/s face velocity

  4. Tooth bleaching using peroxide-containing agents: current status of safety issues.

    Science.gov (United States)

    Li, Y

    1998-08-01

    During the last 10 years, at-home tooth bleaching using peroxide-containing agents has quickly become well accepted. It is one of the most popular cosmetic dental procedures for whitening teeth. Although there are few disputes regarding their efficacy, concerns and debates have continued regarding the safety of peroxide-containing tooth bleaching agents. Potential carcinogenicity and genotoxicity of the peroxides used in bleaching agents are the two most persistent and controversial issues. This article reviews and discusses available information on carcinogenicity and genotoxicity of hydrogen peroxide and the potential risks associated with the use of peroxide-containing bleaching agents. Clinical studies reported after the 1996 international symposium on responses of oral tissues to peroxide-containing bleaching agents are also reviewed. Overall evidence supports the conclusion that the proper use of peroxide-containing at-home tooth bleaching agents is safe. However, potential adverse effects may occur in inappropriate applications, abuses, or the use of inappropriate products. At-home tooth bleaching should be monitored by dental professionals to maximize the benefits while minimizing potential risks.

  5. Effect of newer antioxidants on the bond strength of composite on bleached enamel

    Directory of Open Access Journals (Sweden)

    M Manoharan

    2016-01-01

    Full Text Available Aim: The study aims to evaluate the effect of the application of two antioxidants on the bond strength of composite resin to bleached enamel. Materials and Methods: Eighty enamel surfaces were obtained from forty human extracted premolars. Specimens were randomly divided into four groups (n = 20. Group 1: No bleaching (control; Group 2a: Bleaching with 15% carbamide peroxide gel; Group 2b: Bleaching, followed by application of 10% sodium ascorbate gel; Group 2c: Bleaching, followed by application of 5% proanthocyanidin agent. Surfaces were etched followed by application of total etch bonding system, and composite resin cylinders were bonded. Specimens were tested for shear bond strength. Statistical Analysis Used: One-way analysis of variance was used for multiple group comparison and post hoc Tukey′s test for individual group-wise comparison. Results: Significantly higher shear bond strength values were observed in Group 2c and 2b as compared with Group 1 and 2a (P < 0.05. Among the antioxidants, Group 2c showed significantly higher shear bond strength values than Group 2b (P < 0.05. Conclusion: It can be concluded that the use of antioxidant before bonding procedures on bleached enamel completely neutralizes the deleterious effects of bleaching and increases the bond strength significantly.

  6. Elevated temperatures and bleaching on a high latitude coral reef: the 1988 Bermuda event

    Science.gov (United States)

    Cook, Clayton B.; Logan, Alan; Ward, Jack; Luckhurst, Brian; Berg, Carl J.

    1990-03-01

    Sea temperatures were normal in Bermuda during 1987, when Bermuda escaped the episodes of coral bleaching which were prevalent throughout the Caribbean region. Survey transecs in 1988 on 4 6 m reefs located on the rim margin and on a lagoonal patch reef revealed bleaching only of zoanthids between May and July. Transect and tow surveys in August and September revealed bleaching of several coral species; Millepora alcicornis on rim reefs was the most extensively affected. The frequency of bleaching in this species, Montastrea annularis and perhaps Diploria labyrinthiformis was significantly higher on outer reefs than on inshore reefs. This bleaching period coincided with the longest period of elevated sea temperatures in Bermuda in 38 years (28.9 30.9°C inshore, >28° offshore). By December, when temperatures had returned to normal, bleaching of seleractinians continued, but bleaching of M. alcicornis on the outer reefs was greatly reduced. Our observations suggest that corals which normally experience wide temperature ranges are less sensitive to thermal stress, and that high-latitude reef corals are sensitive to elevated temperatures which are within the normal thermal range of corals at lower latitudes.

  7. Effect of three nanobiomaterials on the surface roughness of bleached enamel

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2015-01-01

    Full Text Available Background: The ever-increasing demand for enhanced esthetic appearance has resulted in significant developments in bleaching products. However, the enamel surface roughness (SR might be negatively affected by bleaching agents. This in vitro study was undertaken to compare the effects of three nanobiomaterials on the enamel SR subsequent to bleaching. Materials and Methods: The crowns of six extracted intact nonerupted human third molars were sectioned. Five dental blocks measuring 2 mm × 3 mm × 4 mm were prepared from each tooth and placed in colorless translucent acrylic resin. The enamel areas from all the specimens were divided into five groups (n = 6: Group 1 did not undergo any bleaching procedures; Group 2 was bleached with a 40% hydrogen peroxide (HP gel; Groups 3, 4, and 5 were bleached with a 40% HP gel modified by bioactive glass (BAG, amorphous calcium phosphate, and hydroxyapatite, respectively. The enamel SR was evaluated before and after treatment by atomic force microscopy. The data were analyzed by Kruskal–Wallis and Mann–Whitney tests. Results: SR increased significantly in the HP group. SR decreased significantly in the HP gel modified by BAG group as compared to other groups. Conclusions: Within the limitations of this study, incorporation of each one of the three test biomaterials proved effective in decreasing enamel SR subsequent to in-office bleaching technique.

  8. Recycling of water in bleached kraft pulp mills by using electrodialysis.

    Energy Technology Data Exchange (ETDEWEB)

    Fracaro, A. T.; Henry, M. P.; Pfromm, P.; Tsai, S.-P.

    1999-01-15

    Conservation of water in bleached kraft pulp mills by recycling the bleach plant effluent directly without treatment will cause accumulation of inorganic ''non-process elements'' (NPEs) and serious operational problems. In this work, an electrodialysis process is being developed for recycling the acidic bleach plant effluent of bleached kraft pulp mills. In this process, electrodialysis functions as a selective kidney to remove inorganic NPEs from bleach plant effluents, before they reach the recovery cycle. Acidic bleach plant effluents from several mills using bleaching sequences based on chlorine dioxide were characterized. The total dissolved solids were mostly inorganic NPEs. Sodium was the predominant cation and chloride was present at significant levels in all these effluents. In laboratory electrodialysis experiments, selective removal of chloride and potentially harmful cations, such as potassium, calcium, and magnesium, were removed efficiently. Rejection of organic compounds was up to 98%. Electrodialysis was shown to be resistant to membrane fouling and scaling, in a 100-hour laboratory experiment. Based on a model mill with 1,000 ton/day pulp production, the economic analysis suggests that the energy cost of electrodialysis is less than $200/day, and the capital cost of the stack is about $500,000.

  9. Influence of bleach activators on the fabric made from cotton (gossypium hamster l.)

    International Nuclear Information System (INIS)

    Asif, H.M.; Iftikhar, M.; Shahbaz, B.

    2013-01-01

    Raw cotton contains various type of trash and most of the impurities are removed during the spinning process but still the cotton fabric coming from the weaving or knitting process always contains some impurities. Some time cotton fabric gets the oil, stains and coloured materials which affect the quality of dyed fabric. Bleaching is a process that eliminates unwanted coloured matters from the fibres, yarn and fabrics. A bleaching agent is a material that lightens or whitens a substrate through chemical action. Hydrogen peroxide is by far the most commonly used oxidative bleaching agent for cotton and its blends, accounting for more than 90 percent of all the bleaching agents. The use of activators to enhance the bleaching performance of hydrogen peroxide for cellulosic materials has gained popularity now a day. In this context the main objectives of this paper are to study the influence of different bleaching activators on cotton fabric and to give implications for textile extension.The results indicate that the activators with different concentrations, along with different concentrations of hydrogen peroxide (H/sub 2/O/sub 2) have significant influence on the bleaching performance of cotton fabric. (author)

  10. Relationships between temperature, bleaching and white syndrome on the Great Barrier Reef

    Science.gov (United States)

    Ban, S. S.; Graham, N. A. J.; Connolly, S. R.

    2013-03-01

    Coral bleaching and disease have often been hypothesized to be mutually reinforcing or co-occurring, but much of the research supporting this has only drawn an implicit connection through common environmental predictors. In this study, we examine whether an explicit relationship between white syndrome and bleaching exists using assemblage-level monitoring data from up to 112 sites on reef slopes spread throughout the Great Barrier Reef over 11 years of monitoring. None of the temperature metrics commonly used to predict mass bleaching performed strongly when applied to these data. Furthermore, the inclusion of bleaching as a predictor did not improve model skill over baseline models for predicting white syndrome. Similarly, the inclusion of white syndrome as a predictor did not improve models of bleaching. Evidence for spatial co-occurrence of bleaching and white syndrome at the assemblage level in this data set was also very weak. These results suggest the hypothesized relationship between bleaching and disease events may be weaker than previously thought, and more likely to be driven by common responses to environmental stressors, rather than directly facilitating one another.

  11. Portable Hybrid Powered Water Filtration Device

    Directory of Open Access Journals (Sweden)

    Maria Lourdes V. Balansay

    2015-08-01

    Full Text Available The existing water filtration device has features that can be developed to be more useful and functional during emergency situations. The project’s development has been aided by following provisions in PEC, NEC, NEMA and Philippine National Standard for Safe Drinking Water provide standards for the construction of the project. These standards protect both the prototype and the user. These also served as guide for the maintenance of every component. The design of the portable hybrid powered water filtration device shows that the project has more advanced features such as portability and the power supply used such as photovoltaic module solar cells and manually operated generator. This also shows its effectiveness and reliability based on the results of discharging test, water quality test and water production test. Based on analysis of the overall financial aspects, the machine can be profitable and the amount of revenue and operating cost will increase as years pass. Using the proper machine/ tools and methods of fabrication helps in easy assembly of the project. The materials and components used are cost effective and efficient. The best time for charging the battery using solar panel is 9:00 am onwards while the hand crank generator is too slow because the generated current is little. The water filtration device is very efficient regarding the operating hours and water production. The machine may have a great effect to society and economy in generation of clean available water at less cost.

  12. Direct filtration of Biesbosch water and Algae and water treatment in the Netherlands : 3rd Direct Filtration Seminar

    NARCIS (Netherlands)

    Petrusevski, B.; Vlaski, A.; Van Breemen, A.N.; Alaerts, G.J.

    1993-01-01

    This presentation summarises basic information on direct filtration, and demonstrates the main research findings, related to the performance of simple in-line direct filtration. The results reported are part of a comprehensive ongoing research programm "Direct filtration of Biesbosch water"

  13. The influence of hair bleach on the ultrastructure of human hair with special reference to hair damage.

    Science.gov (United States)

    Imai, Takehito

    2011-05-01

    The influence of human hair bleaching agents with different bleaching strength on the ultrastructure of human hair was studied using a transmission electron microscope (TEM) and an energy dispersive X-ray spectrometer equipped with TEM (EDS-TEM). Two kinds of bleaching agents were used: a lightener agent with a weak bleaching effect and a powder-bleach with a stronger bleaching effect. From the comparison of the bleaching properties obtained by the electronic staining of black and white hair samples, it was suggested that the permeability of hair was increased by bleaching, and there was an increase of the stainability of hair subjected to electronic staining. The bleaching action provoked the decomposition of melanin granules and the flow out of granular contents into the intermacrofibrillar matrix. Some metal elements were detected in the melanin granular matrix by EDS-TEM. As a result, the diffusion of metal elements into the intermacrofibrillar matrix promoted further damage to the hair by catalytic action with the hydrogen peroxide in the bleaching agents outside the melanin granules. Further study will lead us to the edge of the development of a new bleaching agent, which reacts only with melanin granules and causes the minimum of damage to outside the melanin granules.

  14. Skeletal isotope records of growth perturbations in Porites corals during the 1997-1998 mass bleaching event

    Science.gov (United States)

    Suzuki, A.; Gagan, M.; Fabricius, K.; Isdale, P.; Yukino, I.; Kawahata, H.

    2003-04-01

    Severe coral bleaching occurred throughout the tropics in 1997/98. We report skeletal UV fluorescence, oxygen isotope, and carbon isotope evidence for perturbations in coral skeletal growth due to bleaching at Ishigaki Island, Japan, and Pandora Reef, Great Barrier Reef. Bleached corals showed abrupt reductions in skeletal extension rate immediately after summer temperature maxima, indicating that bleaching inhibits coral calcification. A colony growing at the low tide line in Ishigaki exhibited clear blue UV fluorescent bands associated with recurrent growth interruptions. Based on the length of time-gaps observed in the annual isotopic cycle, the typical time required for a coral to recover from bleaching is estimated to be about 5--6 months. The effect of bleaching on the oxygen isotope ratio -- temperature relationship was negligible. However, the Ishigaki corals showed lower carbon isotope ratios during bleaching indicating depressed coral metabolism associated with a reduction in calcification. In contrast, skeletal carbon isotope ratios in the Pandora Reef corals exhibited little change in response to bleaching. This is because the records for Pandora Reef were derived from the shaded sides of coral colonies, where algal photosynthesis was particularly slow prior to bleaching, thus subduing the carbon isotope response to bleaching. Taken together, the isotopic and UV fluorescence signals can be used to reconstruct past bleaching events.

  15. Management optimization in Thermal complex through water reuse

    International Nuclear Information System (INIS)

    De Souza, S.; Manganelli, A.; Bertolotto, J.; Leys, P.; Garcia, B.

    2004-01-01

    Water reuse involves the concept of the exploitation of a previously used water, for a new, beneficial purpose. Actually, in Uruguay, thermal water is just utilised for balneological purposes, in this paper is proposed the water reuse taking the excess of used swimming pool water, and using it for heating and greenhouse irrigation, and australian lobster breeding. An important aspect of sustainable thermal water management is the protection of the exploted thermal water resources, so water reuse plays an important role in water resource, and ecosystem management, because it reduces the volume discharged and also reduces the risk of thermal pollution [es

  16. A PATTERN LANGUAGE FOR REUSING WEB TEACHING MATERIALS

    Directory of Open Access Journals (Sweden)

    Nadia Bouz-Asal

    2013-12-01

    Full Text Available The Internet enables sharing of content between educators, which can reduce the time and effort needed to create custom teaching materials and improve the quality of students’ learning experiences. There are, however, significant obstacles to effective educational content sharing and reuse, especially in developing countries. To address this problem, we have taken a user-centric approach to discover and analyze teachers’ needs and to understand the main barriers to web content reuse among K-12 educators in Bosnia and Herzegovina. Based on this analysis, we have developed a novel pattern language for reusing web teaching materials.

  17. FCC catalyst finds three safe reuse outlets in Europe

    International Nuclear Information System (INIS)

    Schmitt, R.

    1991-01-01

    This paper reports on three usages in the area of construction materials which offer a potential outlet for the reuse of spent fluid catalytic cracking (FCC) catalyst that far exceeds the supply from European refineries. The proximity of the spent catalyst source to the point-of-use is critical because this determines the transportation cost-the major element in the cost of disposal/reuse. This is why a balance geographical spread of reuse outlets throughout Europe is sought. Asphalt, cement, and red bricks containing spent fluid catalytic cracking catalyst, have all passed environmental acceptability tests

  18. Preserving and reusing high-energy-physics data analyses

    CERN Document Server

    Simko, Tibor; Dasler, Robin; Fokianos, Pamfilos; Kuncar, Jiri; Lavasa, Artemis; Mattmann, Annemarie; Rodriguez, Diego; Trzcinska, Anna; Tsanaktsidis, Ioannis

    2017-01-01

    The revalidation, reuse and reinterpretation of data analyses require having access to the original virtual environments, datasets and software that was used to produce the original scientific result. The CERN Analysis Preservation pilot project is developing a set of tools that support particle physics researchers in preserving the knowledge around analyses so that capturing, sharing, reusing and reinterpreting data becomes easier. In this talk, we shall notably focus on the aspects of reusing a preserved analysis. We describe a system that permits to instantiate the preserved analysis workflow on the computing cloud, paving the way to allowing researchers to revalidate and reinterpret research data even many years after the original publication.

  19. Caribbean corals in crisis: record thermal stress, bleaching, and mortality in 2005.

    Science.gov (United States)

    Eakin, C Mark; Morgan, Jessica A; Heron, Scott F; Smith, Tyler B; Liu, Gang; Alvarez-Filip, Lorenzo; Baca, Bart; Bartels, Erich; Bastidas, Carolina; Bouchon, Claude; Brandt, Marilyn; Bruckner, Andrew W; Bunkley-Williams, Lucy; Cameron, Andrew; Causey, Billy D; Chiappone, Mark; Christensen, Tyler R L; Crabbe, M James C; Day, Owen; de la Guardia, Elena; Díaz-Pulido, Guillermo; DiResta, Daniel; Gil-Agudelo, Diego L; Gilliam, David S; Ginsburg, Robert N; Gore, Shannon; Guzmán, Héctor M; Hendee, James C; Hernández-Delgado, Edwin A; Husain, Ellen; Jeffrey, Christopher F G; Jones, Ross J; Jordán-Dahlgren, Eric; Kaufman, Les S; Kline, David I; Kramer, Philip A; Lang, Judith C; Lirman, Diego; Mallela, Jennie; Manfrino, Carrie; Maréchal, Jean-Philippe; Marks, Ken; Mihaly, Jennifer; Miller, W Jeff; Mueller, Erich M; Muller, Erinn M; Orozco Toro, Carlos A; Oxenford, Hazel A; Ponce-Taylor, Daniel; Quinn, Norman; Ritchie, Kim B; Rodríguez, Sebastián; Ramírez, Alberto Rodríguez; Romano, Sandra; Samhouri, Jameal F; Sánchez, Juan A; Schmahl, George P; Shank, Burton V; Skirving, William J; Steiner, Sascha C C; Villamizar, Estrella; Walsh, Sheila M; Walter, Cory; Weil, Ernesto; Williams, Ernest H; Roberson, Kimberly Woody; Yusuf, Yusri

    2010-11-15

    The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.

  20. Seasonal mesophotic coral bleaching of Stylophora pistillata in the Northern Red Sea.

    Directory of Open Access Journals (Sweden)

    Orit Nir

    Full Text Available Coral bleaching occurs when environmental stress induces breakdown of the coral-algae symbiosis and the host initiates algae expulsion. Two types of coral bleaching had been thoroughly discussed in the scientific literature; the first is primarily associated with mass coral bleaching events; the second is a seasonal loss of algae and/or pigments. Here, we describe a phenomenon that has been witnessed for repeated summers in the mesophotic zone (40-63 m in the northern Red Sea: seasonal bleaching and recovery of several hermatypic coral species. In this study, we followed the recurring bleaching process of the common coral Stylophora pistillata. Bleaching occurred from April to September with a 66% decline in chlorophyll a concentration, while recovery began in October. Using aquarium and transplantation experiments, we explored environmental factors such as temperature, photon flux density and heterotrophic food availability. Our experiments and observations did not yield one single factor, alone, responsible for the seasonal bleaching. The dinoflagellate symbionts (of the genus Symbiodinium in shallow (5 m Stylophora pistillata were found to have a net photosynthetic rate of 56.98-92.19 µmol O2 cm(-2 day(-1. However, those from mesophotic depth (60 m during months when they are not bleached are net consumers of oxygen having a net photosynthetic rate between -12.86 - (-10.24 µmol O2 cm(-2 day(-1. But during months when these mesophotic corals are partially-bleached, they yielded higher net production, between -2.83-0.76 µmol O2 cm(-2 day(-1. This study opens research questions as to why mesophotic zooxanthellae are more successfully meeting the corals metabolic requirements when Chl a concentration decreases by over 60% during summer and early fall.

  1. Caribbean corals in crisis: record thermal stress, bleaching, and mortality in 2005.

    Directory of Open Access Journals (Sweden)

    C Mark Eakin

    Full Text Available BACKGROUND: The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.

  2. Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005

    Science.gov (United States)

    Eakin, C. Mark; Morgan, Jessica A.; Heron, Scott F.; Smith, Tyler B.; Liu, Gang; Alvarez-Filip, Lorenzo; Baca, Bart; Bartels, Erich; Bastidas, Carolina; Bouchon, Claude; Brandt, Marilyn; Bruckner, Andrew W.; Bunkley-Williams, Lucy; Cameron, Andrew; Causey, Billy D.; Chiappone, Mark; Christensen, Tyler R. L.; Crabbe, M. James C; Day, Owen; de la Guardia, Elena; Díaz-Pulido, Guillermo; DiResta, Daniel; Gil-Agudelo, Diego L.; Gilliam, David S.; Ginsburg, Robert N.; Gore, Shannon; Guzmán, Héctor M.; Hendee, James C.; Hernández-Delgado, Edwin A.; Husain, Ellen; Jeffrey, Christopher F. G.; Jones, Ross J.; Jordán-Dahlgren, Eric; Kaufman, Les S.; Kline, David I.; Kramer, Philip A.; Lang, Judith C.; Lirman, Diego; Mallela, Jennie; Manfrino, Carrie; Maréchal, Jean-Philippe; Marks, Ken; Mihaly, Jennifer; Miller, W. Jeff; Mueller, Erich M.; Muller, Erinn M.; Orozco Toro, Carlos A.; Oxenford, Hazel A.; Ponce-Taylor, Daniel; Quinn, Norman; Ritchie, Kim B.; Rodríguez, Sebastián; Ramírez, Alberto Rodríguez; Romano, Sandra; Samhouri, Jameal F.; Sánchez, Juan A.; Schmahl, George P.; Shank, Burton V.; Skirving, William J.; Steiner, Sascha C. C.; Villamizar, Estrella; Walsh, Sheila M.; Walter, Cory; Weil, Ernesto; Williams, Ernest H.; Roberson, Kimberly Woody; Yusuf, Yusri

    2010-01-01

    Background The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. Methodology/Principal Findings Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. Conclusions/Significance Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate. PMID:21125021

  3. Sensory and Functionality Differences of Whey Protein Isolate Bleached by Hydrogen or Benzoyl Peroxide.

    Science.gov (United States)

    Smith, Tucker J; Foegeding, E Allen; Drake, MaryAnne

    2015-10-01

    Whey protein is a highly functional food ingredient used in a wide variety of applications. A large portion of fluid whey produced in the United States is derived from Cheddar cheese manufacture and contains annatto (norbixin), and therefore must be bleached. The objective of this study was to compare sensory and functionality differences between whey protein isolate (WPI) bleached by benzoyl peroxide (BP) or hydrogen peroxide (HP). HP and BP bleached WPI and unbleached controls were manufactured in triplicate. Descriptive sensory analysis and gas chromatography-mass spectrometry were conducted to determine flavor differences between treatments. Functionality differences were evaluated by measurement of foam stability, protein solubility, SDS-PAGE, and effect of NaCl concentration on gelation relative to an unbleached control. HP bleached WPI had higher concentrations of lipid oxidation and sulfur containing volatile compounds than both BP and unbleached WPI (P protein loss at pH 4.6 of WPI decreased by bleaching with either hydrogen peroxide or benzoyl peroxide (P whey with either BP or HP resulted in protein degradation, which likely contributed to functionality differences. These results demonstrate that bleaching has flavor effects as well as effects on many of the functionality characteristics of whey proteins. Whey protein isolate (WPI) is often used for its functional properties, but the effect of oxidative bleaching chemicals on the functional properties of WPI is not known. This study identifies the effects of hydrogen peroxide and benzoyl peroxide on functional and flavor characteristics of WPI bleached by hydrogen and benzoyl peroxide and provides insights for the product applications which may benefit from bleaching. © 2015 Institute of Food Technologists®

  4. Effects of different concentrations of carbamide peroxide and bleaching periods on the roughness of dental ceramics

    Directory of Open Access Journals (Sweden)

    Sérgio Augusto Morey Ourique

    2011-10-01

    Full Text Available The wide use of dental bleaching treatment has brought concern about the possible effects of hydrogen peroxide on dental tissue and restorative materials. The objective of this study was to evaluate in vitro the effect of nightguard bleaching on the surface roughness of dental ceramics after different periods of bleaching treatment. Fifteen specimens of 5 × 3 × 1 mm were created with three dental ceramics following the manufacturers' instructions: IPS Classic (Ivoclar-Vivadent; IPS d.Sign (Ivoclar-Vivadent; and VMK-95 (Vita. A profilometer was used to evaluate baseline surface roughness (Ra values of all ceramics by five parallel measurements with five 0.25 mm cut off (Λc at 0.1 mm/s. Afterwards, all specimens were submitted to 6-h daily bleaching treatments with 10% or 16% carbamide peroxide (Whiteness- FGM for 21 days, while control groups from each ceramic system were stored in artificial saliva. The surface roughness of all groups was evaluated after 18 h, 42 h, 84 h, and 126 h of bleaching treatment. The surface roughness of each specimen (n = 5 was based on the mean value of five parallel measurements in each time and all data were submitted to two-way repeated measures ANOVA and Tukey's post-hoc test (α = 0.05. No significant differences in ceramic surface roughness were observed between untreated and bleached ceramic surfaces, regardless of bleaching intervals or bleaching treatments. This study provided evidence that at-home bleaching systems do not cause detrimental effects on surface roughness of dental ceramics.

  5. The Delineation of Coral Bleaching Thresholds and Future Reef Health, Little Cayman Cayman Islands

    Science.gov (United States)

    Manfrino, C.; Van Hooidonk, R. J.; Manzello, D.; Hendee, J.

    2011-12-01

    The global rise in sea temperature through anthropogenic climate change is affecting coral reef ecosystems through a phenomenon known as coral bleaching; a common reaction to thermally induced physiological stress in reef-building corals that often leads to coral mortality. We describe aspects of the most prevalent episode of coral bleaching ever recorded at Little Cayman, Cayman Islands, during the fall of 2009. Scleractinian coral species exhibiting susceptibility to thermal stress and bleaching in Little Cayman were, in order, Siderastrea siderea, Montastraea annularis, and Montastraea faveolata, while Diplora strigosa and Agaricia spp. were less so, yet still showed considerable bleaching prevalence and severity. In contrast, the least susceptible were Porites porites, Porites astreoides, and Montastraea cavernosa. These observations and other reported observations of coral bleaching, together with 29 years (1982 - 2010) of satellite-derived sea surface temperatures, were used in a Degree Heating Weeks (DHW) and Peirce Skill Score (PSS) analysis to calculate a bleaching threshold above which bleaching was expected to occur. A threshold of 4.2 DHW had the highest skill, with a PSS of 0.70. This threshold and susceptibility ranking are used in combination with SST data from global, coupled ocean-atmosphere general circulation models (GCM) from the fourth IPCC assessment to forecast future reef health on Little Cayman. While these GCMs possess skill in reproducing many aspects of climate, they vary in their ability to correctly capture such parameters as the tropical ocean seasonal cycle and El Niño Southern Oscillation (ENSO) variability. These model weaknesses likely reduce the skill of coral bleaching predictions. To overcome this, a multi-model ensemble of GCMs are corrected for their mean, annual cycle and ENSO variability prior to calculating future thermal stress. Preliminary results show that from 2045 on Little Cayman is likely to see more than two

  6. Seasonal mesophotic coral bleaching of Stylophora pistillata in the Northern Red Sea.

    Science.gov (United States)

    Nir, Orit; Gruber, David F; Shemesh, Eli; Glasser, Eliezra; Tchernov, Dan

    2014-01-01

    Coral bleaching occurs when environmental stress induces breakdown of the coral-algae symbiosis and the host initiates algae expulsion. Two types of coral bleaching had been thoroughly discussed in the scientific literature; the first is primarily associated with mass coral bleaching events; the second is a seasonal loss of algae and/or pigments. Here, we describe a phenomenon that has been witnessed for repeated summers in the mesophotic zone (40-63 m) in the northern Red Sea: seasonal bleaching and recovery of several hermatypic coral species. In this study, we followed the recurring bleaching process of the common coral Stylophora pistillata. Bleaching occurred from April to September with a 66% decline in chlorophyll a concentration, while recovery began in October. Using aquarium and transplantation experiments, we explored environmental factors such as temperature, photon flux density and heterotrophic food availability. Our experiments and observations did not yield one single factor, alone, responsible for the seasonal bleaching. The dinoflagellate symbionts (of the genus Symbiodinium) in shallow (5 m) Stylophora pistillata were found to have a net photosynthetic rate of 56.98-92.19 µmol O2 cm(-2) day(-1). However, those from mesophotic depth (60 m) during months when they are not bleached are net consumers of oxygen having a net photosynthetic rate between -12.86 - (-10.24) µmol O2 cm(-2) day(-1). But during months when these mesophotic corals are partially-bleached, they yielded higher net production, between -2.83-0.76 µmol O2 cm(-2) day(-1). This study opens research questions as to why mesophotic zooxanthellae are more successfully meeting the corals metabolic requirements when Chl a concentration decreases by over 60% during summer and early fall.

  7. Recycling, reducing and reusing: A theoretical framework

    International Nuclear Information System (INIS)

    Kubursi, A.A.; Butterfield, D.W.

    1990-01-01

    Macroeconomic models are generally based on a particular national income accounting framework. The current approach treats waste and pollution generation in such a way that any increase in these activities increases directly the gross domestic product of the economy. A reformulation is suggested for the accounting framework so as to treat waste management and pollution abatement as services to business whose costs should be charged against business revenue. Even such costs to households may be considered as costs to output. In this way such expenses appear as a cost to society and not as a final output. A new theoretical framework is developed to correspond to the reformulated accounting principle that allows clear identification of recycling activity and waste management. The rectangular input-output framework is particularly suited for this treatment as it allows different industries to produce the same output and identifies different commodities as inputs in the production of the same output. With the new framework, it is possible to examine the socioeconomic consequences of increased use and production of recyclables. Equally important is the ability to assess the relative efficiency of alternative policies to reuse or reduce the use of products and resources through price incentives and full cost charges. 2 tabs

  8. Nanofiber filter media for air filtration

    Science.gov (United States)

    Raghavan, Bharath Kumar

    Nanofibers have higher capture efficiencies in comparison to microfibers in the submicron particle size range of 100-500 nm because of small fiber diameter and increased surface area of the fibers. Pressure drop across the filter increases tremendously with decrease in fiber diameter in the continuum flow regime. Nanofibers with fiber diameter less than 300 nm are in the slip flow regime as a consequence of which steep increase in pressure drop is considerably reduced due to slip effect. The outlet or inlet gases have broad range of particle size distribution varying from few micrometers to nanometers. The economic benefits include capture of a wide range of particle sizes in the gas streams using compact filters composed of nanofibers and microfibers. Electrospinning technique was used to successfully fabricate polymeric and ceramic nanofibers. The nanofibers were long, continuous, and flexible with diameters in the range of 200--300 nm. Nanofibers were added to the filter medium either by mixing microfibers and nanofibers or by directly electrospinning nanofibers as thin layer on the surface of the microfiber filter medium. Experimental results showed that either by mixing Nylon 6 nanofibers with B glass fibers or by electrospinning Nylon 6 nanofibers as a thin layer on the surface of the microfiber medium in the surface area ratio of 1 which is 0.06 g of nanofibers for 2 g of microfibers performed better than microfiber filter media in air filtration tests. This improved performance is consistent with numerical modeling. The particle loading on a microfibrous filter were studied for air filtration tests. The experimental and modeling results showed that both pressure drop and capture efficiency increased with loading time. Nanofiber filter media has potential applications in many filtration applications and one of them being hot gas filtration. Ceramic nanofibers made of alumina and titania nanofibers can withstand in the range of 1000°C. Ceramic nanofibers

  9. Filtration approach to mitigate indoor Thoron progeny concentration

    International Nuclear Information System (INIS)

    Wang, J.; Meisenberg, O.; Karg, E.; Tschiersch, J.; Chen, Y.

    2010-01-01

    This study investigates filtration of air as potential mitigation method of thoron progeny exposure. The experiments were conducted in a model room (volume 7.1 m 3 ) which was equipped with a pump and an HEPA (high efficiency particulate air) filter. Filtration at a rate of 0.2, 0.4, 0.5 and 0.8 h -1 during 88 h proved an effective practice in reducing the total indoor thoron decay product concentration. The results indicate that 0.4-0.8 h -1 filtration rate had almost the same filtration efficiency in decreasing the total thoron EEC (equilibrium equivalent concentration) by 97% while 80% of total thoron EEC were reduced by 0.2 h -1 filtration rate; meanwhile, the unattached thoron EEC rose significantly by 190, 270, 290%, respectively under 0.4-0.8 h -1 filtration rate, whereas 0.2 h -1 filtration rate increased unattached thoron EEC by 40%. The aerosol number size distribution variation reveals that filtration operation removes smaller particles faster or earlier than the larger ones. The annual effective dose calculated was reduced by 91-92% at a filtration rate of 0.4-0.8 h -1 while 75% reduced at 0.2 h -1 filtration rate after 88 h filtration process. (authors)

  10. Comparison of Radicular Peroxide Leakage from four Commonly used Bleaching agents following Intracoronal Bleaching in Endodontically treated teeth - An In Vitro Study.

    Science.gov (United States)

    Madhu, Ks; Hegde, Swaroop; Mathew, Sylvia; Lata, DA; Bhandi, Shilpa H; N, Shruthi

    2013-08-01

    Non vital bleaching is simple, conservative procedure for esthetic correction of discolored endodontically treated teeth. The aim of this study was to determine and compare the amount of peroxide leakage from four different bleaching agents i.e superoxol, sodium perborate, combination of superoxol & sodium perborate and carbamide peroxide during intracoronal bleaching, as the safe and effective bleaching is the need of the hour. 50 extracted maxillary centrals were selected for the study. Following standardized protocol access, cleaning and shaping by step back technique and obturation was done using guttapercha and AH plus sealer. Access was sealed with Cavit G and outer root surface was coated with wax and nail varnish. The teeth were separated into crown and root and the root portion was placed in plastic tube containing distilled water for 7days.After incubation, 3mm of gutta-percha was removed below CEJ and 2mm glass ionomer cement base was placed. Grouped into five categories based on the bleaching agent placed in pulp chamber as -group1 (control)-distilled water, group 2-sodium perborate with distilled water , group 3- 30% hydrogen peroxide ,group 4-mixture of sodium perborate and 30% hydrogen peroxide and group 5-10% carbamide peroxide gel. Peroxide leakage was measured after 24hrs using ferrothiocyanate method and optical density using spectrophotometer. Statistical analysis of the data was conducted using ANOVA and multiple comparisons within the groups was done using BONFERRONI method (Post-Hoc tests). The results showed highest peroxide penetration from 30% hydrogen peroxide followed by mixture of sodium perborate with 30% hydrogen peroxide, mixture of sodium perborate with distilled water and least penetration from 10% carbamide peroxide gel. The results were statistically significant. Radicular peroxide leakage in 10% carbamide peroxide was significantly lower than the other tested bleaching agents making it a very safe alternative for intracoronal

  11. Characterization of Filtration Scale-Up Performance

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Richard C.; Billing, Justin M.; Luna, Maria L.; Cantrell, Kirk J.; Peterson, Reid A.; Bonebrake, Michael L.; Shimskey, Rick W.; Jagoda, Lynette K.

    2009-03-09

    The scale-up performance of sintered stainless steel crossflow filter elements planned for use at the Pretreatment Engineering Platform (PEP) and at the Waste Treatment and Immobilization Plant (WTP) were characterized in partial fulfillment (see Table S.1) of the requirements of Test Plan TP RPP WTP 509. This test report details the results of experimental activities related only to filter scale-up characterization. These tests were performed under the Simulant Testing Program supporting Phase 1 of the demonstration of the pretreatment leaching processes at PEP. Pacific Northwest National Laboratory (PNNL) conducted the tests discussed herein for Bechtel National, Inc. (BNI) to address the data needs of Test Specification 24590-WTP-TSP-RT-07-004. Scale-up characterization tests employ high-level waste (HLW) simulants developed under the Test Plan TP-RPP-WTP-469. The experimental activities outlined in TP-RPP-WTP-509 examined specific processes from two broad areas of simulant behavior: 1) leaching performance of the boehmite simulant as a function of suspending phase chemistry and 2) filtration performance of the blended simulant with respect to filter scale-up and fouling. With regard to leaching behavior, the effect of anions on the kinetics of boehmite leaching was examined. Two experiments were conducted: 1) one examined the effect of the aluminate anion on the rate of boehmite dissolution and 2) another determined the effect of secondary anions typical of Hanford tank wastes on the rate of boehmite dissolution. Both experiments provide insight into how compositional variations in the suspending phase impact the effectiveness of the leaching processes. In addition, the aluminate anion studies provide information on the consequences of gibbsite in waste. The latter derives from the expected fast dissolution of gibbsite relative to boehmite. This test report concerns only results of the filtration performance with respect to scale-up. Test results for boehmite

  12. Treatment of Wastewater From Car Washes Using Natural Coagulation and Filtration System

    Science.gov (United States)

    Al-Gheethi, A. A.; Mohamed, R. M. S. R.; Rahman, M. A. A.; Johari, M. R.; Kassim, A. H. M.

    2016-07-01

    Wastewater generated from carwash is one of the main wastewater resources, which contribute effectively in the increasing of environmental contamination due to the chemical characteristics of the car wastes. The present work aimed to develop an integrated treatment system for carwash wastewater based on coagulation and flocculation using Moringa oleifera and Ferrous Sulphate (FeSO4.7H2O) as well as natural filtration system. The carwash wastewater samples were collected from carwash station located at Parit Raja, Johor, Malaysia. The treatment system of car wash wastewater was designed in the lab scale in four stages included, aeration, coagulation and flocculation, sedimentation and filtration. The coagulation and flocculation unit was carried out using different dosage (35, 70, 105 and 140 mg L-1) of M. oleifera and FeSO4.7H2O, respectively. The efficiency of the integrated treatment system to treat carwash wastewater and to meet Environmental Quality Act (EQA 1974) was evaluated based on the analysis of pH, dissolved oxygen (DO), chemical oxygen demand (COD) and turbidity (NTU). The integrated treatment system was efficient for treatment of raw carwash wastewater. The treated carwash wastewaters meet EQA 1974 regulation 2009 (Standards A) in the term of pH and DO while, turbidity and COD reduced in the wastewater to meet Standards B. The integrated treatment system designed here with natural coagulant (M. oleifera) and filtration unit were effective for primary treatment of carwash wastewater before the final disposal or to be reused again for carwash process.

  13. A Community-Driven Workflow Recommendation and Reuse Infrastructure

    Data.gov (United States)

    National Aeronautics and Space Administration — Promote and encourage process and workflow reuse  within NASA Earth eXchange (NEX) by developing a proactive recommendation technology based on collective NEX user...

  14. Proceedings of Trombay symposium on desalination and water reuse

    International Nuclear Information System (INIS)

    1999-12-01

    The symposium Desalination and Water Reuse gave an overview of desalination technologies, R and D on desalination, a few case studies of large size desalination plants and desalination using nuclear energy. The papers related to INIS are indexed separately

  15. Re-use of seedling containers and Fusarium circinatum association ...

    African Journals Online (AJOL)

    Re-use of seedling containers and Fusarium circinatum association with asymptomatic Pinus patula planting stock. Andrew R Morris, Gerda Fourie, Izette Greyling, Emma T Steenkamp, Nicoletta B Jones ...

  16. Development of Policies, Institutions and Procedures for Water Reuse

    Science.gov (United States)

    Demouche, L.; Pfiefer, J.; Hanson, A.; Skaggs, R.

    2009-12-01

    In the arid, water scarce region of New Mexico and West Texas there is growing interest in the potential for water reuse to extend existing supplies and mitigate drought shortage impacts. There are no new sources of water in New Mexico, except reclaimed water. Communities and individuals are uncertain about and have many unanswered questions about polices, institutions involved (agencies), legal and regulatory requirements, and procedures governing water reuse. Issues to be addressed by this project include: the legal ability to reuse water, ownership of water rights, downstream or third party impacts, regulatory and procedural requirements, water quality concerns, state and local agency involvement, and cost effectiveness of water reuse compared to alternative sources. Presently, there is very little implementation or directives in New Mexico policy that addresses reuse, reclamation, or recycled water. The only regulations pertaining to reuse is New Mexico Environmental Department currently allows the use of reclaimed domestic wastewater for irrigation of golf courses and green spaces, which is listed in the Policy for the Above Ground Use of Reclaimed Domestic Wastewater (NMED, 2003). This document identifies the various reclaimed quality classifications that are required for specific applications and the permits required for application. This document does not identify or address policy applications on the distribution, ownership, or trading of reclaimed water. Even though reclaimed water reuse projects are currently being implemented in many cities in the U.S., mainly for commercial and municipal irrigation (golf courses and green space), its potential has not yet been exploited. A policy analysis matrix (PAM) is being designed to identify and examine the policy framework and consequences of non-policy implementation for decision makers and interest groups and assist them in understanding the consequences of policy actions and project outcomes if no laws or

  17. Measurement and characterization of filtration efficiencies for prefilter materials used in aerosol filtration

    International Nuclear Information System (INIS)

    Sciortino, J.

    1991-01-01

    In applications where the filtration of large quantities of mixed (liquid and solid) aerosols is desired, a multistage filtration system is often employed. This system consists of a prefilter, a High Efficiency Particulate Air (HEPA) filter, and any number of specialized filters particular to the filtration application. The prefilter removes liquids and any large particles from the air stream, keeping them from prematurely loading the HEPA filter downstream. The HEPA filter eliminates 99.97% of all particulates in the aerosol. The specialized filters downstream of the HEPA filter can be used to remove organic volatiles or other vapors. While the properties of HEPA filters have been extensively investigated, literature characterizing the prefilter is scarce. The purpose of this report is to characterize the efficiency of the prefilter as a function of particle size, nature of the particle (solid or liquid), and the gas flow rate across the face of the prefilter. 1 ref., 4 figs

  18. Structuring Formal Requirements Specifications for Reuse and Product Families

    Science.gov (United States)

    Heimdahl, Mats P. E.

    2001-01-01

    In this project we have investigated how formal specifications should be structured to allow for requirements reuse, product family engineering, and ease of requirements change, The contributions of this work include (1) a requirements specification methodology specifically targeted for critical avionics applications, (2) guidelines for how to structure state-based specifications to facilitate ease of change and reuse, and (3) examples from the avionics domain demonstrating the proposed approach.

  19. Dissolved effluent organic matter: Characteristics and potential implications in wastewater treatment and reuse applications.

    Science.gov (United States)

    Michael-Kordatou, I; Michael, C; Duan, X; He, X; Dionysiou, D D; Mills, M A; Fatta-Kassinos, D

    2015-06-15

    Wastewater reuse is currently considered globally as the most critical element of sustainable water management. The dissolved effluent organic matter (dEfOM) present in biologically treated urban wastewater, consists of a heterogeneous mixture of refractory organic compounds with diverse structures and varying origin, including dissolved natural organic matter, soluble microbial products, endocrine disrupting compounds, pharmaceuticals and personal care products residues, disinfection by-products, metabolites/transformation products and others, which can reach the aquatic environment through discharge and reuse applications. dEfOM constitutes the major fraction of the effluent organic matter (EfOM) and due to its chemical complexity, it is necessary to utilize a battery of complementary techniques to adequately describe its structural and functional character. dEfOM has been shown to exhibit contrasting effects towards various aquatic organisms. It decreases metal uptake, thus potentially reducing their bioavailability to exposed organisms. On the other hand, dEfOM can be adsorbed on cell membranes inducing toxic effects. This review paper evaluates the performance of various advanced treatment processes (i.e., membrane filtration and separation processes, activated carbon adsorption, ion-exchange resin process, and advanced chemical oxidation processes) in removing dEfOM from wastewater effluents. In general, the literature findings reveal that dEfOM removal by advanced treatment processes depends on the type and the amount of organic compounds present in the aqueous matrix, as well as the operational parameters and the removal mechanisms taking place during the application of each treatment technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Decontamination and reuse of ORGDP aluminum scrap

    International Nuclear Information System (INIS)

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Wilson, D.F.

    1996-12-01

    The Gaseous Diffusion Plants, or GDPs, have significant amounts of a number of metals, including nickel, aluminum, copper, and steel. Aluminum was used extensively throughout the GDPs because of its excellent strength to weight ratios and good resistance to corrosion by UF 6 . This report is concerned with the recycle of aluminum stator and rotor blades from axial compressors. Most of the stator and rotor blades were made from 214-X aluminum casting alloy. Used compressor blades were contaminated with uranium both as a result of surface contamination and as an accumulation held in surface-connected voids inside of the blades. A variety of GDP studies were performed to evaluate the amounts of uranium retained in the blades; the volume, area, and location of voids in the blades; and connections between surface defects and voids. Based on experimental data on deposition, uranium content of the blades is 0.3%, or roughly 200 times the value expected from blade surface area. However, this value does correlate with estimated internal surface area and with lengthy deposition times. Based on a literature search, it appears that gaseous decontamination or melt refining using fluxes specific for uranium removal have the potential for removing internal contamination from aluminum blades. A melt refining process was used to recycle blades during the 1950s and 1960s. The process removed roughly one-third of the uranium from the blades. Blade cast from recycled aluminum appeared to perform as well as blades from virgin material. New melt refining and gaseous decontamination processes have been shown to provide substantially better decontamination of pure aluminum. If these techniques can be successfully adapted to treat aluminum 214-X alloy, internal and, possibly, external reuse of aluminum alloys may be possible

  1. Scenario of solid waste reuse in Khulna city of Bangladesh

    International Nuclear Information System (INIS)

    Bari, Quazi H.; Mahbub Hassan, K.; Haque, R.

    2012-01-01

    The reuse and recycling of waste materials are now sincerely considered to be an integral part of solid waste management in many parts of the world. In this context, a vast number of options ranging from small scale decentralized to larger scale centralized plants have been adopted. This study aimed at investigating the waste reuse schemes in Khulna city located in the southern part of Bangladesh and ranked third largest city in the country. The shops for reusable material (SRM) were mostly situated around railway, waterway, and truck station markets which provided easy transportation to further locations. For the reuses of waste materials and products, a chain system was found to collect reusable wastes under a total number of 310 identified SRM with 859 persons directly or indirectly involved in the scheme. This was a decentralized waste management system with self sufficient (autonomous) management. According to mass balance, about 38.52 tons d −1 solid wastes were reused in Khulna city area, accounting for 7.65% of the total generated wastes. This study revealed that apparently a silent, systematic, smooth, and clean reuse chain has been established in Khulna city area under private initiatives, whose sustainability was confirmed over the years in the country without any official or formal funds. However, proper adjustment between the higher and lower chain in the materials flow path, as well as personal hygiene training for the workers, would further improve the achievements of the established reuse scheme.

  2. Optimal waste heat recovery and reuse in industrial zones

    International Nuclear Information System (INIS)

    Stijepovic, Mirko Z.; Linke, Patrick

    2011-01-01

    Significant energy efficiency gains in zones with concentrated activity from energy intensive industries can often be achieved by recovering and reusing waste heat between processing plants. We present a systematic approach to target waste heat recovery potentials and design optimal reuse options across plants in industrial zones. The approach first establishes available waste heat qualities and reuse feasibilities considering distances between individual plants. A targeting optimization problem is solved to establish the maximum possible waste heat recovery for the industrial zone. Then, a design optimization problem is solved to identify concrete waste heat recovery options considering economic objectives. The paper describes the approach and illustrates its application with a case study. -- Highlights: → Developed a systematic approach to target waste heat recovery potentials and to design optimal recovery and reuse options across plants in industrial zones. → Five stage approach involving data acquisition, analysis, assessment, targeting and design. → Targeting optimization problem establishes the maximum possible waste heat recovery and reuse limit for the industrial zone. → Design optimization problem provides concrete waste heat recovery and reuse network design options considering economic objectives.

  3. Performance Analysis of Reuse Distance in Cooperative Broadcasting

    Directory of Open Access Journals (Sweden)

    Jimmi Grönkvist

    2016-01-01

    Full Text Available Cooperative broadcasting is a promising technique for robust broadcast with low overhead and delay in mobile ad hoc networks. The technique is attractive for mission-oriented mobile communication, where a majority of the traffic is of broadcast nature. In cooperative broadcasting, all nodes simultaneously retransmit packets. The receiver utilizes cooperative diversity in the simultaneously received signals. The retransmissions continue until all nodes are reached. After the packet has traveled a specific number of hops out from the source, denoted as reuse distance, the source node transmits a new broadcast packet in the time slot used for the previous broadcast packet. If the reuse distance is too small, interference causes packet loss in intermediate nodes. In the literature, a reuse distance of three is common. With an analysis based on a realistic interference model and real terrain data, we show that a reuse distance of at least four is necessary to avoid packet loss in sparsely connected networks, especially for high spectral efficiencies. For frequency hopping, widely used in military systems, we propose a novel method. This method almost eliminates interference for a reuse distance of three, increasing the throughput by 33% compared to systems with a reuse distance of four.

  4. Scenario of solid waste reuse in Khulna city of Bangladesh.

    Science.gov (United States)

    Bari, Quazi H; Mahbub Hassan, K; Haque, R

    2012-12-01

    The reuse and recycling of waste materials are now sincerely considered to be an integral part of solid waste management in many parts of the world. In this context, a vast number of options ranging from small scale decentralized to larger scale centralized plants have been adopted. This study aimed at investigating the waste reuse schemes in Khulna city located in the southern part of Bangladesh and ranked third largest city in the country. The shops for reusable material (SRM) were mostly situated around railway, waterway, and truck station markets which provided easy transportation to further locations. For the reuses of waste materials and products, a chain system was found to collect reusable wastes under a total number of 310 identified SRM with 859 persons directly or indirectly involved in the scheme. This was a decentralized waste management system with self sufficient (autonomous) management. According to mass balance, about 38.52 tons d(-1) solid wastes were reused in Khulna city area, accounting for 7.65% of the total generated wastes. This study revealed that apparently a silent, systematic, smooth, and clean reuse chain has been established in Khulna city area under private initiatives, whose sustainability was confirmed over the years in the country without any official or formal funds. However, proper adjustment between the higher and lower chain in the materials flow path, as well as personal hygiene training for the workers, would further improve the achievements of the established reuse scheme. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Optical Emission Spectroscopy of an Atmospheric Pressure Plasma Jet During Tooth Bleaching Gel Treatment.

    Science.gov (United States)

    Šantak, Vedran; Zaplotnik, Rok; Tarle, Zrinka; Milošević, Slobodan

    2015-11-01

    Optical emission spectroscopy was performed during atmospheric pressure plasma needle helium jet treatment of various tooth-bleaching gels. When the gel sample was inserted under the plasma plume, the intensity of all the spectral features increased approximately two times near the plasma needle tip and up to two orders of magnitude near the sample surface. The color change of the hydroxylapatite pastille treated with bleaching gels in conjunction with the atmospheric pressure plasma jet was found to be in correlation with the intensity of OH emission band (309 nm). Using argon as an additive to helium flow (2 L/min), a linear increase (up to four times) of OH intensity and, consequently, whitening (up to 10%) of the pastilles was achieved. An atmospheric pressure plasma jet activates bleaching gel, accelerates OH production, and accelerates tooth bleaching (up to six times faster).

  6. Use of xylanase in the TCF bleaching of eucalyptus kraft pulp

    Energy Technology Data Exchange (ETDEWEB)

    Roncero, B.; Vidal, T.; Torres, A.L.; Colom, J.F. [Universitat Politecnia de Catalunya, Terrassa (Spain)

    1996-10-01

    Environmental pressures are forcing the pulp and paper industry to develop new technologies that reduce or eliminate the presence of various contaminants in bleaching plant effluents. Oxygen delignification techniques, replacement of elemental chlorine with chlorine dioxide, ozone, hydrogen peroxide and new agents as well as the use of xylanase enzymes for biobleaching, reduce o eliminate the production of chlorinated organic substances. This paper compares the sequence XOZP with OZP in the bleaching of Eucalyptus globulus kraft pulps. It has been studied the influence of enzymatic treatment on the consumption of bleaching agents: ozone and hydrogen peroxide. Chemical, physical, optical and refining properties of pulps, as well as COD and colour of effluent are also studied. The xylanase treatment is positive and it is possible to manufacture fully bleached pulps at high brightness and viscosity without using chlorine compounds at a low ozone and hydrogen peroxide consumption.

  7. Sugar enrichment provides evidence for a role of nitrogen fixation in coral bleaching

    KAUST Repository

    Pogoreutz, Claudia

    2017-04-21

    The disruption of the coral-algae symbiosis (coral bleaching) due to rising sea surface temperatures has become an unprecedented global threat to coral reefs. Despite decades of research, our ability to manage mass bleaching events remains hampered by an incomplete mechanistic understanding of the processes involved. In this study, we induced a coral bleaching phenotype in the absence of heat and light stress by adding sugars. The sugar addition resulted in coral symbiotic breakdown accompanied by a fourfold increase of coral-associated microbial nitrogen fixation. Concomitantly, increased N:P ratios by the coral host and algal symbionts suggest excess availability of nitrogen and a disruption of the nitrogen limitation within the coral holobiont. As nitrogen fixation is similarly stimulated in ocean warming scenarios, here we propose a refined coral bleaching model integrating the cascading effects of stimulated microbial nitrogen fixation. This model highlights the putative role of nitrogen-fixing microbes in coral holobiont functioning and breakdown.

  8. Post-bleaching coral community change on southern Maldivian reefs: is there potential for rapid recovery?

    Science.gov (United States)

    Perry, C. T.; Morgan, K. M.

    2017-12-01

    Given the severity of the 2016 global bleaching event, there are major questions about how quickly reef communities will recover. Here, we explore the ecological and physical structural changes that occurred across five atoll interior reefs in the southern Maldives using data collected at 6 and 12 months post-bleaching. Following initial severe coral mortality, further minor coral mortality had occurred by 12 months post-bleaching, and coral cover is now low (<6%). In contrast, reef rugosity has continued to decline over time, and our observations suggest transitions to rubble-dominated states will occur in the near future. Juvenile coral densities in shallow fore-reef habitats are also exceptionally low (<6 individuals m-2), well below those measured 9-12 months following the 1998 bleaching event, and below recovery thresholds identified on other Indian Ocean reefs. Our findings suggest that the physical structure of these reefs will need to decline further before effective recruitment and recovery can begin.

  9. NOAA's Coral Reef Conservation Program: 2016 Projects Monitoring the Effects of Thermal Stress on Coral Bleaching

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Climate change impacts have been identified as one of the greatest global threats to coral reef ecosystems. As temperature rise, mass bleaching, and infectious...

  10. Physicochemical properties and oxidative stability of bleached pomace-olive oil on Tunisian activated clays

    International Nuclear Information System (INIS)

    Jahouach, Wafa

    2002-01-01

    This work is a contribution to studying bleaching process, which is an important stage in refining of vegetable oils. This process permitted to reduce or convert undesired constituents to harmless ones from oils and fats. Virgin olive oil, considered as reference, and pomace-olive oil were bleached in optimal conditions using Tunisian activated clays ( collected from the South of Tunisia) which were prepared in our laboratory and compared with commercial bleaching earths. It was shown that activated Tunisian clays are characterized by a very important adsorptive capacity, which is similar to that of commercial ones. In addition, the study of physicochemical properties of bleached oils was considered. The fatty acid composition (GC), the triacylglycerol composition (HPLC), and oxidative stability (UV spectrometry) allowed to conclude that treated oils do not undergo considerable physicochemical alterations and their caracteristics remain in concordance with international standards relative to edible refined oils. (Author)

  11. Short-term coral bleaching is not recorded by skeletal boron isotopes.

    Science.gov (United States)

    Schoepf, Verena; McCulloch, Malcolm T; Warner, Mark E; Levas, Stephen J; Matsui, Yohei; Aschaffenburg, Matthew D; Grottoli, Andréa G

    2014-01-01

    Coral skeletal boron isotopes have been established as a proxy for seawater pH, yet it remains unclear if and how this proxy is affected by seawater temperature. Specifically, it has never been directly tested whether coral bleaching caused by high water temperatures influences coral boron isotopes. Here we report the results from a controlled bleaching experiment conducted on the Caribbean corals Porites divaricata, Porites astreoides, and Orbicella faveolata. Stable boron (δ11B), carbon (δ13C), oxygen (δ18O) isotopes, Sr/Ca, Mg/Ca, U/Ca, and Ba/Ca ratios, as well as chlorophyll a concentrations and calcification rates were measured on coral skeletal material corresponding to the period during and immediately after the elevated temperature treatment and again after 6 weeks of recovery on the reef. We show that under these conditions, coral bleaching did not affect the boron isotopic signature in any coral species tested, despite significant changes in coral physiology. This contradicts published findings from coral cores, where significant decreases in boron isotopes were interpreted as corresponding to times of known mass bleaching events. In contrast, δ13C and δ18O exhibited major enrichment corresponding to decreases in calcification rates associated with bleaching. Sr/Ca of bleached corals did not consistently record the 1.2°C difference in seawater temperature during the bleaching treatment, or alternatively show a consistent increase due to impaired photosynthesis and calcification. Mg/Ca, U/Ca, and Ba/Ca were affected by coral bleaching in some of the coral species, but the observed patterns could not be satisfactorily explained by temperature dependence or changes in coral physiology. This demonstrates that coral boron isotopes do not record short-term bleaching events, and therefore cannot be used as a proxy for past bleaching events. The robustness of coral boron isotopes to changes in coral physiology, however, suggests that reconstruction of

  12. The impact of iron on the bleaching efficacy of hydrogen peroxide in liquid whey systems.

    Science.gov (United States)

    Jervis, Suzanne M; Drake, MaryAnne

    2013-02-01

    Whey is a value-added product that is utilized in many food and beverage applications for its nutritional and functional properties. Whey and whey products are generally utilized in dried ingredient applications. One of the primary sources of whey is from colored Cheddar cheese manufacture that contains the pigment annatto resulting in a characteristic yellow colored Cheddar cheese. The colorant is also present in the liquid cheese whey and must be bleached so that it can be used in ingredient applications without imparting a color. Hydrogen peroxide and benzoyl peroxide are 2 commercially approved chemical bleaching agents for liquid whey. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have been previously reported for whey bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how bleaching can impact flavor and functionality of dried ingredients. Currently, the precise mechanisms of off-flavor development and functionality changes are not entirely understood. Iron reactions in a bleached liquid whey system may play a key role. Reactions between iron and hydrogen peroxide have been widely studied since the reaction between these 2 relatively stable species can cause great destruction in biological and chemical systems. The actual mechanism of the reaction of iron with hydrogen peroxide has been a controversy in the chemistry and biological community. The precise mechanism for a given reaction can vary greatly based upon the concentration of reactants, temperature, pH, and addition of biological material. In this review, some hypotheses for the mechanisms of iron reactions that may occur in fluid whey that may impact bleaching efficacy, off-flavor development, and changes in functionality are presented. Cheese whey is bleached to remove residual carotenoid cheese colorant. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have

  13. The effect of bleaching agent on the flavor of liquid whey and whey protein concentrate.

    Science.gov (United States)

    Croissant, A E; Kang, E J; Campbell, R E; Bastian, E; Drake, M A

    2009-12-01

    The increasing use and demand for whey protein as an ingredient requires a bland-tasting, neutral-colored final product. The bleaching of colored Cheddar whey is necessary to achieve this goal. Currently, hydrogen peroxide (HP) and benzoyl peroxide (BPO) are utilized for bleaching liquid whey before spray drying. There is no current information on the effect of the bleaching process on the flavor of spray-dried whey protein concentrate (WPC). The objective of this study was to characterize the effect of bleaching on the flavor of liquid and spray-dried Cheddar whey. Cheddar cheeses colored with water-soluble annatto were manufactured in duplicate. Four bleaching treatments (HP, 250 and 500 mg/kg and BPO, 10 and 20 mg/kg) were applied to liquid whey for 1.5 h at 60 degrees C followed by cooling to 5 degrees C. A control whey with no bleach was also evaluated. Flavor of the liquid wheys was evaluated by sensory and instrumental volatile analysis. One HP treatment and one BPO treatment were subsequently selected and incorporated into liquid whey along with an unbleached control that was processed into spray-dried WPC. These trials were conducted in triplicate. The WPC were evaluated by sensory and instrumental analyses as well as color and proximate analyses. The HP-bleached liquid whey and WPC contained higher concentrations of oxidation reaction products, including the compounds heptanal, hexanal, octanal, and nonanal, compared with unbleached or BPO-bleached liquid whey or WPC. The HP products were higher in overall oxidation products compared with BPO samples. The HP liquid whey and WPC were higher in fatty and cardboard flavors compared with the control or BPO samples. Hunter CIE Lab color values (L*, a*, b*) of WPC powders were distinct on all 3 color scale parameters, with HP-bleached WPC having the highest L* values. Hydrogen peroxide resulted in a whiter WPC and higher off-flavor intensities; however, there was no difference in norbixin recovery between HP

  14. Influence of pH, bleaching agents, and acid etching on surface wear of bovine enamel

    Science.gov (United States)

    Soares, Ana Flávia; Bombonatti, Juliana Fraga Soares; Alencar, Marina Studart; Consolmagno, Elaine Cristina; Honório, Heitor Marques; Mondelli, Rafael Francisco Lia

    2016-01-01

    ABSTRACT Development of new materials for tooth bleaching justifies the need for studies to evaluate the changes in the enamel surface caused by different bleaching protocols. Objective The aim of this study was to evaluate the bovine dental enamel wear in function of different bleaching gel protocols, acid etching and pH variation. Material and Methods Sixty fragments of bovine teeth were cut, obtaining a control and test areas. In the test area, one half received etching followed by a bleaching gel application, and the other half, only the bleaching gel. The fragments were randomly divided into six groups (n=10), each one received one bleaching session with five hydrogen peroxide gel applications of 8 min, activated with hybrid light, diode laser/blue LED (HL) or diode laser/violet LED (VHL) (experimental): Control (C); 35% Total Blanc Office (TBO35HL); 35% Lase Peroxide Sensy (LPS35HL); 25% Lase Peroxide Sensy II (LPS25HL); 15% Lase Peroxide Lite (LPL15HL); and 10% hydrogen peroxide (experimental) (EXP10VHL). pH values were determined by a pHmeter at the initial and final time periods. Specimens were stored, subjected to simulated brushing cycles, and the superficial wear was determined (μm). ANOVA and Tukey´s tests were applied (α=0.05). Results The pH showed a slight decrease, except for Group LPL15HL. Group LPS25HL showed the highest degree of wear, with and without etching. Conclusion There was a decrease from the initial to the final pH. Different bleaching gels were able to increase the surface wear values after simulated brushing. Acid etching before bleaching increased surface wear values in all groups. PMID:27008254

  15. Understanding the Nature and Reactivity of Residual Lignin for Improved Pulping and Bleaching Efficiency; FINAL

    International Nuclear Information System (INIS)

    Yuan-Zong Lai

    2001-01-01

    One of the most formidable challenges in kraft pulping to produce bleached chemical pulps is how to effectively remove the last 5-10% of lignin while maintaining the fiber quality. To avoid a severe fiber degradation, kraft pulping is usually terminated in the 25-30 kappa number range and then followed by an elementally chlorine free (ECF) or a totally chlorine free (TCF) bleaching sequence to reduce the environmental impacts

  16. Effects of staining and bleaching on color change of dental composite resins.

    Science.gov (United States)

    Villalta, Patricia; Lu, Huan; Okte, Zeynep; Garcia-Godoy, Franklin; Powers, John M

    2006-02-01

    Discoloration of resin-based composites by colored solutions is a common problem. The use of bleaching agents for discolored natural teeth is becoming increasingly popular. It is not clear if bleaching agents can remove the stain from composite resins. The purpose of this study was to investigate the effects of 2 staining solutions and 3 bleaching systems on the color changes of 2 dental composite resins. Forty-five disk-shaped specimens (9 x 2.5 mm) of each of 2 composite resins, Filtek Supreme (FS) and Esthet X (EX), were prepared. The specimens were then divided into 3 groups of 15 specimens each and immersed in 2 staining solutions (coffee or red wine) or distilled water (control) for 3 hours daily over a 40-day test period. The 3 groups were then divided into 3 subgroups (n = 5), and 3 bleaching agents (Crest Night Effects, Colgate Simply White Night, or Opalescence Quick) were applied to the surface of the specimens over a 14-day period. Color of the specimens was measured with a spectrophotometer using CIELAB color space relative to CIE standard illuminant D55 at baseline, after staining, and after bleaching. The color differences (deltaE(ab)*) between the 3 measurements were calculated. The value deltaE(ab)* = 3.3 was used as an acceptable value in subjective visual evaluations. Analysis of variance and nonparametric analysis (Kruskal-Wallis test and Mann-Whitney test) were used to analyze the data. After staining, FS had more color change than EX and was more affected by the wine solution. After bleaching, the color of both EX and FS specimens returned to the baseline. The color differences between bleaching and baseline were less than value deltaE(ab)* = 3.3 for all groups. The nanocomposite (FS) changed color more than the microhybrid composite (EX) as a result of staining in coffee or red wine solutions. After bleaching, discoloration was removed completely from the composite resins tested.

  17. Effects of Light Activation, Agent Concentration, and Tooth Thickness on Dental Sensitivity After Bleaching

    OpenAIRE

    Moncada, G.; Sepulveda, D.; Elphick, K.; Contente, M.; Estay, J.; Bahamondes, V.; Fernandez, E.; Oliveira, O. B. [UNESP; Martin, J.

    2013-01-01

    Examining three bleaching systems, this in vivo clinical trial evaluated the relationship among tooth sensitivity, light activation, and agent concentration, and it correlated dental sensitivity with tooth thickness.Materials and Methods: Eighty-seven volunteer patients were included. Inclusion criteria were the presence of anterior teeth without restorations as well as the absence of a previous bleaching experience and absence of non-carious cervical lesions or dental pain. Exclusion criteri...

  18. Understanding the Nature and Reactivity of Residual Lignin for Improved Pulping and Bleaching Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Yuan-Zong Lai

    2001-11-30

    One of the most formidable challenges in kraft pulping to produce bleached chemical pulps is how to effectively remove the last 5-10% of lignin while maintaining the fiber quality. To avoid a severe fiber degradation, kraft pulping is usually terminated in the 25-30 kappa number range and then followed by an elementally chlorine free (ECF) or a totally chlorine free (TCF) bleaching sequence to reduce the environmental impacts.

  19. Study of fish oil bleaching using the sodium bentonite through a factorial design

    OpenAIRE

    Marcia Regina Simões; Reinaldo Aparecido Bariccatti; Caio Guilherme Secco Souza; José Dilson Silva de Oliveira

    2011-01-01

    This work was a experimental design in order to optimize the process of bleaching of fish oil, using the sodium bentonite as adsorbent, from the influence of variables such as weight of sodium bentonite, the temperature process, thermal activation of sodium bentonite and time of agitation. It was then possible to fit a mathematical model with the influence of each variable in the process of bleaching of the oil. The response variable was the absorbance at 444 nm.

  20. Study of fish oil bleaching using the sodium bentonite through a factorial design

    Directory of Open Access Journals (Sweden)

    Marcia Regina Simões

    2011-06-01

    Full Text Available This work was a experimental design in order to optimize the process of bleaching of fish oil, using the sodium bentonite as adsorbent, from the influence of variables such as weight of sodium bentonite, the temperature process, thermal activation of sodium bentonite and time of agitation. It was then possible to fit a mathematical model with the influence of each variable in the process of bleaching of the oil. The response variable was the absorbance at 444 nm.

  1. Study on the Modification of Bleached Eucalyptus Kraft Pulp Using Birch Xylan

    Science.gov (United States)

    Wenjia Han; Chuanshan Zhao; Thomas Elder; Rendang Yang; Dongho Kim; Yunqiao Pu; Jeffery Hsieh; Arthur J. Ragauskas

    2012-01-01

    In this study, birch xylan was deposited onto elementally chlorine free (ECF) bleached eucalyptus kraft pulp, and the corresponding changes in physical properties were determined. An aqueous 5% birch xylan solution at pH 9 was added to 5 wt% slurry of bleached kraft eucalyptus fibers, with stirring at 70 C for 15 min after which the pH was adjusted to 5–6. The xylan...

  2. Effect of postoperative bleaching on microleakage of etch-and-rinse and self-etch adhesives

    Directory of Open Access Journals (Sweden)

    Vajihesadat Mortazavi

    2011-01-01

    Full Text Available Background: Bleaching the discoloured teeth may affect the tooth/composite interface. The aim of this in vitro experimental study was to evaluate the effect of vital tooth bleaching on microleakage of existent class V composite resin restorations bonded with three dental bonding agents. Methods : Class V cavities were prepared on buccal surfaces of 72 intact, extracted human anterior teeth with gingival margins in dentin and occlusal margins in enamel, and randomly divided into 3 groups. Cavities in the three groups were treated with Scotch bond Multi-Purpose, a total etch system and Prompt L-Pop and iBond, two self-etch adhesives. All teeth were restored with Z250 resin composite material and thermo-cycled. Each group was equally divided into the control and the bleached subgroups (n = 12. The bleached subgroups were bleached with 15% carbamide peroxide gel for 8 hours a day for 15 days. Microleakage scores were evaluated on the incisal and cervical walls. Data were analyzed using Kruskal-Wallis, Mann-Whitney and Bonferroni post-hoc tests (α = 0.05. Results: Bleaching with carbamide peroxide gel significantly increased the microleakage of composite restorations in Prompt L-Pop group at dentinal walls (P = 0.001. Bleaching had no effect on microleakage of restorations in the Scotch bond Multi-Purpose and iBond groups. Conclusion: Vital tooth bleaching with carbamide peroxide gel has an adverse effect on marginal seal of dentinal walls of existent composite resin restorations bonded with prompt L-Pop self-etch adhesive.

  3. The effect of baking soda when applied to bleached enamel prior to restorative treatment.

    Science.gov (United States)

    Tostes, Bhenya Ottoni; Mondelli, Rafael Francisco Lia; Lima-Arsati, Ynara Bosco de Oliveira; Rodrigues, Jose Augusto; Costa, Leonardo Cesar

    2013-08-01

    This in vitro study evaluated the effect of 10% baking soda solution and sodium bicarbonate powder (applied with jets) when applied to bleached enamel prior to restorative treatment. The surfaces of 40 bovine incisors were flattened and divided into 5 groups (n = 8): Group B (bleached and restored, negative control), Group W (bleached, stored in distilled water for 7 days, and restored), Group BSJ (bleached, abraded with baking soda jet for 1 min, and restored), Group BSS (bleached, application of 10% baking soda solution for 5 min, and restored), and Group R (restored, without bleaching, positive control). The samples were bleached in 1 session with 3 applications of 35% HP-based gel and activated with a LED appliance for 9 min each. Resin composite cylinders (2 mm height and 0.8 mm diameter) were made on the enamel surface after the acid etching and a conventional 1-step single vial adhesive application was performed. After storage in distilled water (37 ± 1°C, 24 hr), the microshear bond test was performed (1 mm/min). ANOVA and Tukey tests were applied to compare the results. The mean results of these tests showed that Groups W, BBS, and R were not statistically different. These groups also indicated a higher bond strength when compared with Groups B and BSJ. The application of 10% baking soda solution for 5 min may be an alternative pre-restorative treatment for bleached enamel, but further studies are needed to consider whether or not this treatment may be effectively used in clinical practice.

  4. Photoconductivity and bleaching of trapped electrons at 770C in irradiated methylcyclohexane

    International Nuclear Information System (INIS)

    Dolivo, G.; Gaeumann, T.

    1977-01-01

    The influence of the wavelength and intensity of the bleaching radiation on the thermoluminescence, thermoconductivity, optical absorption and photoconductivity of the methylcyclohexane, protonated and deuterated, was studied. The energy level scheme of the trapped electron in this alkane is very similar to that found in MTHF and 3-MP. The rate of bleaching of the trapped electrons is less in the deuterated product. (U.K.)

  5. Predicting Heat Stress to Inform Reef Management: NOAA Coral Reef Watch's 4-Month Coral Bleaching Outlook

    OpenAIRE

    Gang Liu; Gang Liu; C. Mark Eakin; Mingyue Chen; Arun Kumar; Jacqueline L. De La Cour; Jacqueline L. De La Cour; Scott F. Heron; Scott F. Heron; Scott F. Heron; Erick F. Geiger; Erick F. Geiger; William J. Skirving; William J. Skirving; Kyle V. Tirak

    2018-01-01

    The U.S. National Oceanic and Atmospheric Administration's (NOAA) Coral Reef Watch (CRW) operates a global 4-Month Coral Bleaching Outlook system for shallow-water coral reefs in collaboration with NOAA's National Centers for Environmental Prediction (NCEP). The Outlooks are generated by applying the algorithm used in CRW's operational satellite coral bleaching heat stress monitoring, with slight modifications, to the sea surface temperature (SST) predictions from NCEP's operational Climate F...

  6. High-resolution modeling of thermal thresholds and environmental influences on coral bleaching for local and regional reef management.

    Science.gov (United States)

    Kumagai, Naoki H; Yamano, Hiroya

    2018-01-01

    Coral reefs are one of the world's most threatened ecosystems, with global and local stressors contributing to their decline. Excessive sea-surface temperatures (SSTs) can cause coral bleaching, resulting in coral death and decreases in coral cover. A SST threshold of 1 °C over the climatological maximum is widely used to predict coral bleaching. In this study, we refined thermal indices predicting coral bleaching at high-spatial resolution (1 km) by statistically optimizing thermal thresholds, as well as considering other environmental influences on bleaching such as ultraviolet (UV) radiation, water turbidity, and cooling effects. We used a coral bleaching dataset derived from the web-based monitoring system Sango Map Project, at scales appropriate for the local and regional conservation of Japanese coral reefs. We recorded coral bleaching events in the years 2004-2016 in Japan. We revealed the influence of multiple factors on the ability to predict coral bleaching, including selection of thermal indices, statistical optimization of thermal thresholds, quantification of multiple environmental influences, and use of multiple modeling methods (generalized linear models and random forests). After optimization, differences in predictive ability among thermal indices were negligible. Thermal index, UV radiation, water turbidity, and cooling effects were important predictors of the occurrence of coral bleaching. Predictions based on the best model revealed that coral reefs in Japan have experienced recent and widespread bleaching. A practical method to reduce bleaching frequency by screening UV radiation was also demonstrated in this paper.

  7. The effect of penbutolol on glomerular filtration

    International Nuclear Information System (INIS)

    Meyer, B.H.; Muller, F.O.; Lotter, M.G.; Iturralde, M.P.; Grigoleit, H.-G.

    1981-01-01

    Penbutolol, a new β-adrenoceptor blocker, was found to increase the glomerular filtration rate (GFR) significantly (16%) relative to placebo when administered orally in a dose of 40 mg daily for 7 consecutive days to healthy males. Measurements were performed after the seventh dose. In contrast, a single acute intravenous dose of penbutolol 4 mg did not influence the GFR, which was determined by means of a gamma counter after intravenous injection of technetium-99m diethylenetriamine-penta-acetic acid. Since penbutolol possesses moderate β-adrenomimetic activity, it is postulated that the observed increase in the GFR after oral penbutolol could be due to increased cardiac output at rest

  8. Investigation of Microgranular Adsorptive Filtration System

    Science.gov (United States)

    Cai, Zhenxiao

    Over the past few decades, enormous advances have been made in the application of low-pressure membrane filtration to both drinking water and wastewater treatment. Nevertheless, the full potential of this technology has not been reached, due primarily to limitations imposed by membrane fouling. In drinking water treatment, much of the fouling is caused by soluble and particulate natural organic matter (NOM). Efforts to overcome the problem have focused on removal of NOM from the feed solution, usually by addition of conventional coagulants like alum and ferric chloride (FeCl3) or adsorbents like powdered activated carbon (PAC). While coagulants and adsorbents can remove a portion of the NOM, their performance with respect to fouling control has been inconsistent, often reducing fouling but sometimes having no effect or even exacerbating fouling. This research investigated microgranular adsorptive filtration (muGAF), a process that combines three existing technologies---granular media filtration, packed bed adsorption, and membrane filtration---in a novel way to reduce membrane fouling while simultaneously removing NOM from water. In this technology, a thin layer of micron-sized adsorbent particles is deposited on the membrane prior to delivering the feed to the system. The research reported here represents the first systematic study of muGAF, and the results demonstrate the promising potential of this process. A new, aluminum-oxide-based adsorbent---heated aluminum oxide particles (HAOPs)---was synthesized and shown to be very effective for NOM removal as well as fouling reduction in muGAF systems. muGAF has also been demonstrated to work well with powdered activated carbon (PAC) as the adsorbent, but not as well as when HAOPs are used; the process has also been successful when used with several different membrane types and configurations. Experiments using a wide range of operational parameters and several analytical tools lead to the conclusion that the fouling

  9. Comparative aspects of glomerular filtration in vertebrates.

    Science.gov (United States)

    Yokota, S D; Benyajati, S; Dantzler, W H

    1985-01-01

    Glomerular ultrafiltration of the plasma is a fundamental component of vertebrate renal function. The importance of the glomerulus is reflected by its near-universal presence and great elaboration among the vertebrates. Although the general structural features and functional properties of the glomerulus appear to be largely similar among diverse groups, there exists considerable variation in the magnitude of the rate of filtration. The kidney is the primary vertebrate organ responsible for water and metabolic waste excretion, and glomerular filtration plays an important role in these functions. Therefore, the magnitude of the GFR appears to be influenced primarily by the rates of water influx and metabolism. Major phylogenetic differences in morphological, physiological and metabolic design have a decisive impact on the magnitude of the GFR. The endothermic classes, with more numerous glomeruli, high metabolic rates, and high ultrafiltration pressures, have proportionately higher rates of glomerular filtration than the ectothermic groups. As a group, the reptiles, with presumably the lowest rates of water influx, exhibit the lowest GFRs. Within each class, there are trends toward species with greater access to free water having higher GFRs (e.g. fresh water vs. marine; mesic vs. xeric. The clearest examples exist for the teleosts, with marine forms having lower GFRs than their fresh water relatives. The coupling of the GFR to environmental influences is also demonstrated by the response of the animal to environmentally imposed perturbations, such as dehydration. In terrestrial animals during dehydration, reductions in the rate of glomerular filtration occur reducing the rate of urinary water loss. And increases in GFR appears to be important in the rapid elimination of water loads in nonmammalian vertebrates. This short-term modulation of the GFR occurs by either changing glomerular plasma flow or glomerular capillary hydrostatic pressure, or both. In addition

  10. Gas filtration in binary fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, J. (Univ. de Castilla-La Mancha, Ciudad Real (Spain)); Guardiola, J.; Romero, A. (Univ. de Alcala de Henares, Madrid (Spain))

    1992-12-01

    A systematic experimental study of aerosol filtration in a binary fluidized bed of dielectric material is carried out. Measurements of the collection efficiency when such parameters as gas velocity, bed height, collecting mixture, and column diameter are varied over a wide range have been made. Experimental evidence is given to show that charges generated naturally by triboelectrification of the bed dielectric particles can considerably increase the efficiency of such beds. Furthermore, it is demonstrated that a proper choice of the fluidized mixture can significantly improve the performance of such filters.

  11. A rigid porous filter and filtration method

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, Ta-Kuan; Straub, Douglas, Straub L.; Dennis, Richard A.

    1998-12-01

    The present invention involves a porous rigid filter comprising a plurality of concentric filtration elements having internal flow passages and forming external flow passages there between. The present invention also involves a pressure vessel containing the filter for the removal of particulate from high pressure particulate containing gases, and further involves a method for using the filter to remove such particulate. The present filter has the advantage of requiring fewer filter elements due to the high surface area- to-volume ratio provided by the filter, requires a reduced pressure vessel size, and exhibits enhanced mechanical design properties, improved cleaning properties, configuration options, modularity and ease of fabrication.

  12. Limitation of releases and filtration by sand

    International Nuclear Information System (INIS)

    Schektman, N.

    1986-01-01

    In the highly hypothetic case of a severe reactor accident, it may lead to an increase of pressure within the containment and up to a value above the calculated pressure. A procedure is necessary in this case to maintain the integrity of the containment to prevent a release of radioactive products to the environment, while controlling in the best way releases. So, EDF and the CEA have developed a device of decompression-filtration of the containment atmosphere, using a free penetration of the containment and a sand box; the device and its operation constitute the U5 procedure [fr

  13. Does a toothpaste containing blue covarine have any effect on bleached teeth? An in vitro, randomized and blinded study.

    Science.gov (United States)

    Bortolatto, Janaina Freitas; Dantas, Andrea Abi Rached; Roncolato, Ávery; Merchan, Hugo; Floros, Michael Christopher; Kuga, Milton Carlos; Oliveira Junior, Osmir Batista de

    2016-01-01

    The objective of this study was to analyze the effect of bleaching toothpastes, both conventional and those containing the new whitening agent Blue Covarine, on teeth previously bleached by conventional techniques (in-office and at-home). Squared bovine enamel/dentin blocks (6.0 x 6.0 x 2.0 mm) were randomly distributed in 6 groups (n = 15), according to the technique used to bleach them (in-office: HP35%; at-home: PC10%) and the type of bleaching toothpaste (none: control; Blue Covarine containing: BC; and without Blue Covarine: NBC). Experimental groups denominated HP35%, HP35%BC and HP35%NBC received in-office tooth bleaching before toothbrushing, and groups PC10%, PC10%BC and PC10%NBC were subjected to at-home tooth bleaching prior to toothbrushing. After bleaching treatment, groups HP35%BC, PC10%BC, HP35%NBC and PC10%NBC underwent daily tooth brushing in a brushing machine for 3 minutes (150 strokes/min, with a load of 375 g). Tooth color alteration was measured by reflectance spectroscopy (Vita EasyShade, Vident, Brea, CA, USA) at: T0 (baseline) - after in-office or at-home bleaching treatment; T1 - immediately after tooth brushing; T2 - 7 days and T3 - 14 days after tooth brushing. Data was analyzed by repeated measures mixed ANOVA and the Bonferroni post hoc test, with a significance level of 5%. Statistically significant differences were found between different experimental groups, evaluation times and for the interaction between them (p brushing using either bleaching toothpaste (conventional or with Blue Covarine) showed no color alteration on teeth previously bleached by in-office and at-home tooth bleaching. The use of bleaching toothpastes on previously bleached teeth did not produce a color alteration.

  14. Does a toothpaste containing blue covarine have any effect on bleached teeth? An in vitro, randomized and blinded study

    Directory of Open Access Journals (Sweden)

    Janaina Freitas BORTOLATTO

    2016-01-01

    Full Text Available Abstract The objective of this study was to analyze the effect of bleaching toothpastes, both conventional and those containing the new whitening agent Blue Covarine, on teeth previously bleached by conventional techniques (in-office and at-home. Squared bovine enamel/dentin blocks (6.0 x 6.0 x 2.0 mm were randomly distributed in 6 groups (n = 15, according to the technique used to bleach them (in-office: HP35%; at-home: PC10% and the type of bleaching toothpaste (none: control; Blue Covarine containing: BC; and without Blue Covarine: NBC. Experimental groups denominated HP35%, HP35%BC and HP35%NBC received in-office tooth bleaching before toothbrushing, and groups PC10%, PC10%BC and PC10%NBC were subjected to at-home tooth bleaching prior to toothbrushing. After bleaching treatment, groups HP35%BC, PC10%BC, HP35%NBC and PC10%NBC underwent daily tooth brushing in a brushing machine for 3 minutes (150 strokes/min, with a load of 375 g. Tooth color alteration was measured by reflectance spectroscopy (Vita EasyShade, Vident, Brea, CA, USA at: T0 (baseline – after in-office or at-home bleaching treatment; T1 – immediately after tooth brushing; T2 - 7 days and T3 - 14 days after tooth brushing. Data was analyzed by repeated measures mixed ANOVA and the Bonferroni post hoc test, with a significance level of 5%. Statistically significant differences were found between different experimental groups, evaluation times and for the interaction between them (p < 0.001. Tooth brushing using either bleaching toothpaste (conventional or with Blue Covarine showed no color alteration on teeth previously bleached by in-office and at-home tooth bleaching. The use of bleaching toothpastes on previously bleached teeth did not produce a color alteration.

  15. Pulpal inflammation after vital tooth bleaching with 38% hydrogen peroxide

    Directory of Open Access Journals (Sweden)

    Ardiny Andriani

    2012-06-01

    Full Text Available Background: In-office vital tooth bleaching is a treatment to remove tooth stains. Tooth sensitivity is one of side effect commonly complained by patients receiving this treatment. Purpose: The aim of this study was to examine histological inflammatory cells infiltration of dental pulp after application of 38% H2O2 as a vital tooth bleaching agent. Methods: Under informed consent, a total of 15 premolars from 8 healthy subjects scheduled for orthodontic extraction were used in this study. Thirty eight percent H2O2 was applied on the buccal surface of the treated group. The treated teeth were extracted after 1 hour, 5, 8, and 15 days. All specimens were embedded in paraffin wax, sectioned serially and stained with Hematoxyllin Eosin. Histological specimens were then observed under a light microscope. Results: All treated groups showed a slight disorganization of odontoblasts layer and slight inflammation in the pulp tissue adjacent to the 38% H2O2 application site. The number of polymorphonuclear leukocytes (PMN had increased significantly 1 hour after application of 38% H2O2 (p<0.05, while macrophages had significantly increased 5 days after the application (p<0.05. The most intense PMN and macrophages infiltration was found 5 days after the application and gradually decreased 8 days after application of38% H2O2. Conclusion: Application of 38% H2O2 as a vital tooth bleaching agent induces acute inflammation in human dental pulp; however, the inflammation will decrease 8 days after the application.Latar belakang: Perawatan pemutihan gigi vital metode in-office merupakan tindakan untuk menghilangkan pewarnaan pada gigi. Salah satu efek samping yang sering dikeluhkan oleh pasien yang menjalani perawatan ini adalah sensitivitas gigi. Tujuan: Penelitian ini bertujuan untuk mengamati infiltrasi sel inflamasi pada pulpa gigi setelah aplikasi H2O2 38% sebagai bahan pemutih gigi. Metode: Sampel penelitian ini berupa 15 gigi premolar yang berasal dari 8

  16. Effect of delaying toothbrushing during bleaching on enamel surface roughness: an in vitro study.

    Science.gov (United States)

    Navimipour, E J; Mohammadi, N; Mostafazadeh, S; Ghojazadeh, M; Oskoee, P A

    2013-01-01

    This study aimed to evaluate the effect of toothbrushing on enamel surface roughness at three different intervals after daily bleaching treatment. Eighty enamel slabs were initially evaluated for surface roughness and then randomly divided into four groups. The bleaching procedure was carried out for 21 days, six hours daily. In the control group (group 1), the specimens were not brushed after bleaching, but in groups 2-4, they were brushed with toothpaste immediately, one hour, or two hours after bleaching, respectively. Then the specimens were stored in artificial saliva. Enamel surface roughness was reevaluated at the end of the period. Kruskal-Wallis and Mann-Whitney U tests showed statistically significant differences in the means of surface roughness values between the immediately brushed group and the three other groups (ptoothbrushing immediately after bleaching increased enamel surface roughness; however, postponing the procedure for one or two hours after daily bleaching and exposing the specimens to artificial saliva during the study period resulted in enamel surface roughness comparable to that of the control group.

  17. Improved microscopical detection of acid-fast bacilli by the modified bleach method in lymphnode aspirates

    Directory of Open Access Journals (Sweden)

    Annam Vamseedhar

    2009-07-01

    Full Text Available Objectives: To improve the smear microscopy for detection of acid-fast bacilli (AFB in fine needle aspiration cytology (FNAC of lymph node using the bleach method and also to compare this with cytological diagnosis and the conventional Ziehl-Neelsen (ZN method. Study Design: In 99 consecutive patients with clinical suspicion of tuberculosis (TB presenting with lymphadenopathy, FNACs were performed. Smears from the aspirates were processed for routine cytology and the conventional ZN method. The remaining material in the needle hub and/or the syringe was used for the bleach method. The significance of the bleach method over the conventional ZN method and cytology was analyzed using the χ2 test. Results: Of 99 aspirates, 93 were studied and the remaining six were excluded from the study due to diagnosis of malignancy in 4.04% (4/6 and inadequate aspiration in 2.02% (2/6. Among the 93 aspirates, 33.33% (31/93 were positive for AFB on conventional ZN method, 41.94% (39/93 were indicative of TB on cytology and the smear positivity increased to 63.44% (59/93 on bleach method. Conclusion: The bleach method is simple, inexpensive and potent disinfectant, also limiting the risk of laboratory-acquired infections. The implementation of the bleach method clearly improves microscopic detection and can be a useful contribution to routine cytology.

  18. Effect of two bleaching agents on enamel morphology: a SEM study

    Directory of Open Access Journals (Sweden)

    Ghavam M.

    2005-05-01

    Full Text Available Statement of Problem: Bleaching materials are able to change the surface morphology as well as mineral and organic content of tooth structure. Considering that bleaching is done for aesthetic purpose, awareness of the possible effect of these materials on hard tissue is important, because it may affect the restorative treatments. Purpose: The aim of this study was comparing the effect of two bleaching materials, Kimia and Ultradent both containing 35% H2O2, on tooth enamel by SEM. Materials and Methods: Five intact central incisors were cut into three sections vertically and each part was randomly divided into three groups. Group 1 (control, without any bleaching. Group 2, bleached with Kimia 35% H2O2. Group 3, bleached with Ultradent 35% H2O2. Each tooth served as its own control. Then the samples were observed by SEM with 250 and 500 magnifications. Results: In the control group some scratches and small white grains were observed which seems to be the result of mastication trauma and pumice powder. In the other groups, morphologic changes like increased surface roughness, deepening of cracks, rod exposure and presence of new cracks were observed. The two experimental materials did not differ in these regards. Conclusion: It seems that both studied materials have limited destructive effects on tooth enamel which seems to be of no clinical importance.

  19. Effect of Bleaching Gels on Surface Roughness of Nanofilled Composite Resins

    Science.gov (United States)

    Wang, Linda; Francisconi, Luciana Fávaro; Atta, Maria Teresa; dos Santos, Jean Rodrigo; Del Padre, Natália Coelho; Gonini, Alcides; Fernandes, Karen Barros Parron

    2011-01-01

    Objectives: The aim of this study was to investigate the superficial texture of composite restorations after different bleaching protocols. Methods: Filtek Supreme (S), Filtek Z350 (F), and Grandio (G) were compared to Opallis (O) and Filtek Z250 (Z) (control microhybrid composites) and to bovine enamel using three different bleaching agents: 35% hydrogen peroxide Whiteness HP (WHP), 35% Whiteness HP MAXX (WMAXX) and 16% carbamide peroxide Whiteness Standard (WS). Six specimens from each composite were treated using each bleaching agent, according to the manufacturers’ instructions. Three random sites were measured for superficial roughness (Hommel Tester T 1000) weekly for each sample. Data were analyzed for each bleaching system using two-way ANOVA and Bonferroni tests at 5% significance level. Results: WHP treatment significantly altered the Filtek Supreme composite over time. When WMAXX was used, Grandio displayed the most significant alterations in surface roughness throughout the evaluation period, which was not observed for the other nanocomposites. Using WS, Filtek Z250 presented significant surface alterations over time, which was not seen in the nanofilled materials. Conclusions: Surface roughness alteration was material and time-dependent. The bleaching gels affected nanofilled and microhybrid composite resins. Enamel was the surface less affected by bleaching. PMID:21494385

  20. Effect of Home Bleaching on Microleakage of Fiber-reinforced and Particle-filled Composite Resins

    Directory of Open Access Journals (Sweden)

    Farahnaz Sharafeddin

    2013-12-01

    Full Text Available Background and aims. Bleaching may exert some negative effects on existing composite resin restorations. The aim of this study was to evaluate the effect of home bleaching on microleakage of fiber-reinforced and particle-filled composite resins. Materials and methods. Ninety class V cavities (1.5×2×3 mm were prepared on the buccal surfaces of 90 bovine teeth. The teeth were randomly divided into 6 groups (n=15 and restored as follows: Groups 1 and 2 with Z100, groups 3 and 4 with Z250, and groups 5 and 6 with Nulite F composite resins. All the specimens were thermocycled. Groups 1, 3 and 5 were selected as control groups (without bleaching and the experimental groups 2, 4 and 6 were bleached with 22% carbamide peroxide gel. All the samples were immersed in 2% basic fuchsin dye for 24 hours and then sectioned longitudinally. Dye penetration was evaluated under a stereomicroscope (×25, at both the gingival and incisal margins. Data were analyzed using Kruskal-Wallis, Mann-Whitney and Wilcoxon tests (α=0.05. Results. Statistical analyses revealed that bleaching gel increased microleakage only at gingival margins with Z250 (P=0.007. Moreover, the control groups showed a statistically significant difference in microleakage at their gingival margins. Nulite F had the maximum microleakage while Z250 showed the minimum (P=0.006. Conclusion. Microleakage of home-bleached restorations might be related to the type of composite resin used.

  1. An effective ostrich oil bleaching technique using peroxide value as an indicator.

    Science.gov (United States)

    Palanisamy, Uma Devi; Sivanathan, Muniswaran; Radhakrishnan, Ammu Kutty; Haleagrahara, Nagaraja; Subramaniam, Thavamanithevi; Chiew, Gan Seng

    2011-07-05

    Ostrich oil has been used extensively in the cosmetic and pharmaceutical industries. However, rancidity causes undesirable chemical changes in flavour, colour, odour and nutritional value. Bleaching is an important process in refining ostrich oil. Bleaching refers to the removal of certain minor constituents (colour pigments, free fatty acid, peroxides, odour and non-fatty materials) from crude fats and oils to yield purified glycerides. There is a need to optimize the bleaching process of crude ostrich oil prior to its use for therapeutic purposes. The objective of our study was to establish an effective method to bleach ostrich oil using peroxide value as an indicator of refinement. In our study, we showed that natural earth clay was better than bentonite and acid-activated clay to bleach ostrich oil. It was also found that 1 hour incubation at a 150 °C was suitable to lower peroxide value by 90%. In addition, the nitrogen trap technique in the bleaching process was as effective as the continuous nitrogen flow technique and as such would be the recommended technique due to its cost effectiveness.

  2. An Effective Ostrich Oil Bleaching Technique Using Peroxide Value as an Indicator

    Directory of Open Access Journals (Sweden)

    Gan Seng Chiew

    2011-07-01

    Full Text Available Ostrich oil has been used extensively in the cosmetic and pharmaceutical industries. However, rancidity causes undesirable chemical changes in flavour, colour, odour and nutritional value. Bleaching is an important process in refining ostrich oil. Bleaching refers to the removal of certain minor constituents (colour pigments, free fatty acid, peroxides, odour and non-fatty materials from crude fats and oils to yield purified glycerides. There is a need to optimize the bleaching process of crude ostrich oil prior to its use for therapeutic purposes. The objective of our study was to establish an effective method to bleach ostrich oil using peroxide value as an indicator of refinement. In our study, we showed that natural earth clay was better than bentonite and acid-activated clay to bleach ostrich oil. It was also found that 1 hour incubation at a 150 °C was suitable to lower peroxide value by 90%. In addition, the nitrogen trap technique in the bleaching process was as effective as the continuous nitrogen flow technique and as such would be the recommended technique due to its cost effectiveness.

  3. Graded changes in enamel component volumes resulted from a short tooth bleaching procedure.

    Science.gov (United States)

    Ferreira, Artemisa Fernanda Moura; Perez, Flávia Maria de Moraes Ramos; Limeira Júnior, Francisco de Assis; de Moura, Mirella de Fátima Liberato; de Sousa, Frederico Barbosa

    2016-05-01

    To test the hypothesis that changes in enamel component volumes (mineral, organic, and water volumes, and permeability) are graded from outer to inner enamel after a short bleaching procedure. Extracted unerupted human third molars had half of their crowns bleached (single bleaching session, 3 × 15 min), and tooth shade changes in bleached parts were analyzed with a spectrophotometer. Ground sections were prepared, component volumes and permeability were quantified at histological points located at varying distances from the enamel surface (n=10 points/location), representing conditions before and after bleaching. Tooth shade changes were significant (pvolume (in decreasing order of relevance: mineral loss, organic gain, water gain, and decrease in permeability) with the set of distances from the enamel surface (graded from the enamel surface inward) (canonical R(2)=0.97; p99%). Changes in enamel composition after a short bleaching procedure followed a gradient within component volumes (mineral loss>organic gain>water gain>decrease in permeability) and decreased from the enamel surface inward. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Proteomic analysis of bleached and unbleached Acropora palmata, a threatened coral species of the Caribbean.

    Science.gov (United States)

    Ricaurte, Martha; Schizas, Nikolaos V; Ciborowski, Pawel; Boukli, Nawal M

    2016-06-15

    There has been an increase in the scale and frequency of coral bleaching around the world due mainly to changes in sea temperature. This may occur at large scales, often resulting in significant decline in coral coverage. In order to understand the molecular and cellular basis of the ever-increasing incidence of coral bleaching, we have undertaken a comparative proteomic approach with the endangered Caribbean coral Acropora palmata. Using a proteomic tandem mass spectrometry approach, we identified 285 and 321 expressed protein signatures in bleached and unbleached A. palmata colonies, respectively, in southwestern Puerto Rico. Overall the expression level of 38 key proteins was significantly different between bleached and unbleached corals. A wide range of proteins was detected and categorized, including transcription factors involved mainly in heat stress/UV responses, immunity, apoptosis, biomineralization, the cytoskeleton, and endo-exophagocytosis. The results suggest that for bleached A. palmata, there was an induced differential protein expression response compared with those colonies that did not bleach under the same environmental conditions. Published by Elsevier Ltd.

  5. Transcriptomic responses to darkness stress point to common coral bleaching mechanisms

    Science.gov (United States)

    Desalvo, M. K.; Estrada, A.; Sunagawa, S.; Medina, Mónica

    2012-03-01

    Coral bleaching occurs in response to numerous abiotic stressors, the ecologically most relevant of which is hyperthermic stress due to increasing seawater temperatures. Bleaching events can span large geographic areas and are currently a salient threat to coral reefs worldwide. Much effort has been focused on understanding the molecular and cellular events underlying bleaching, and these studies have mainly utilized heat and light stress regimes. In an effort to determine whether different stressors share common bleaching mechanisms, we used complementary DNA (cDNA) microarrays for the corals Acropora palmata and Montastraea faveolata (containing >10,000 features) to measure differential gene expression during darkness stress. Our results reveal a striking transcriptomic response to darkness in A. palmata involving chaperone and antioxidant up-regulation, growth arrest, and metabolic modifications. As these responses were previously measured during thermal stress, our results suggest that different stressors may share common bleaching mechanisms. Furthermore, our results point to hypoxia and endoplasmic reticulum stress as critical cellular events involved in molecular bleaching mechanisms. On the other hand, we identified a meager transcriptomic response to darkness in M. faveolata where gene expression differences between host colonies and sampling locations were greater than differences between control and stressed fragments. This and previous coral microarray studies reveal the immense range of transcriptomic responses that are possible when studying two coral species that differ greatly in their ecophysiology, thus pointing to the importance of comparative approaches in forecasting how corals will respond to future environmental change.

  6. Patient and environmental service employee satisfaction of using germicidal bleach wipes for patient room cleaning.

    Science.gov (United States)

    Aronhalt, Kimberly C; McManus, James; Orenstein, Robert; Faller, Rebecca; Link, Mary

    2013-01-01

    More healthcare institutions are using bleach products which are sporicidal to reduce Clostridium difficile infection (CDI). There may be patient and employee concerns about the appearance of bleach residue left on surfaces, odors, and respiratory tract irritation. The intervention used bleach wipes for daily and terminal patient room cleaning to reduce transmission of CDI and was implemented on patient care units with a relatively high incidence of CDI. Both patients and Environmental Services (ES) staff were surveyed to assess their satisfaction of the bleach wipe product used during room cleaning. Patients (n = 94) (91%) continued to be very satisfied with how well their rooms were cleaned every day. Bleach wipes were well tolerated by patients (n = 44) (100%) surveyed on the medical units and less tolerated by patients (n = 50) (22%) on the hematology-oncology units. ES staff (6) reported less satisfaction and more respiratory irritation from using the bleach wipes; however, later their satisfaction improved. © 2012 National Association for Healthcare Quality.

  7. A Strategic Framework for Responding to Coral Bleaching Events in a Changing Climate

    Science.gov (United States)

    Maynard, J. A.; Johnson, J. E.; Marshall, P. A.; Eakin, C. M.; Goby, G.; Schuttenberg, H.; Spillman, C. M.

    2009-07-01

    The frequency and severity of mass coral bleaching events are predicted to increase as sea temperatures continue to warm under a global regime of rising ocean temperatures. Bleaching events can be disastrous for coral reef ecosystems and, given the number of other stressors to reefs that result from human activities, there is widespread concern about their future. This article provides a strategic framework from the Great Barrier Reef to prepare for and respond to mass bleaching events. The framework presented has two main inter-related components: an early warning system and assessment and monitoring. Both include the need to proactively and consistently communicate information on environmental conditions and the level of bleaching severity to senior decision-makers, stakeholders, and the public. Managers, being the most timely and credible source of information on bleaching events, can facilitate the implementation of strategies that can give reefs the best chance to recover from bleaching and to withstand future disturbances. The proposed framework is readily transferable to other coral reef regions, and can easily be adapted by managers to local financial, technical, and human resources.

  8. Study of the hydrogen peroxide bleaching agent effects on bovine enamel using X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Ruda F.; Calazans, Fernanda S.; Miranda, Mauro S.; Santos, Ramon S.; Anjos, Marcelino J.; Assis, Joaquim T. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    Hydrogen Peroxide's a bleaching agent capable of oxidizing a wide range of colored organic, causing discoloration and hence bleaching of the substrate, but some authors related the occurrence of side effects related to bleaching of the tooth structure, such as changes in morphology superficial. It was used 6 bovine incisors, each tooth was initially evaluated six times in different areas to obtain the count of elements phosphorus and calcium using X-Ray Fluorescence. The teeth were randomly divided in two groups: both groups were submitted to bleaching in office with hydrogen peroxide 38%, once a week during three weeks. Group 1 was stored in distilled water and group 2 in artificial saliva, between the sessions. The measurements were repeated every seven days before the bleaching treatment. Besides that, changes in mineral levels were always assessed in the same area and using the same procedure. It was observed that the bleaching was not able to demineralize the tooth enamel studied. (author)

  9. Clareamento gengival: ensino e etnocentrismo Gingival bleaching: teaching and ethnocentrism

    Directory of Open Access Journals (Sweden)

    Edson Daruich Bolla

    2010-06-01

    Full Text Available O estudo objetivou identificar os padrões de estética bucal/gengival subjacentes à formação e prática profissional do cirurgião-dentista, na perspectiva do etnocentrismo. A partir da análise documental e da realização de entrevistas (semiestruturadas com cirurgiões dentistas formados há dez ou mais anos, o estudo recorreu a uma abordagem qualitativa, ancorada na análise temática. No âmbito do ensino da periodontia, o estudo evidenciou que a presença da pigmentação fisiológica é omitida ou tratada como uma alteração de normalidade e/ou antiestética. Todos os entrevistados aprenderam a realizar o clareamento gengival em nível de pós-graduação, sendo estimulados a ofertar tal procedimento em nome de um sorriso saudável e bonito. Diante da supervalorização da eficiência da técnica, ressalta a ausência da discussão da questão estética na perspectiva étnica. Parece que a oferta do clareamento gengival se faz norteada pelo padrão branco de beleza, evidenciando o caráter etnocêntrico do procedimento.The aim of this study was to identify buccal/gingival cosmetic dentistry patterns subjacent to formation and professional practice of the dental surgeon from the ethnocentrism point of view. This is an exploratory study with a qualitative approach based on the thematic analysis. Initially a documental analysis was carried out. Thereafter, dental surgeons were interviewed and semi-structured questions were applied. In the Periodontal teaching field, this study showed that the presence of racial melanosis is omitted or treated as an alteration in the normality patterns and it is considered anti-aesthetic. All the interviewers learnt how to practice gingival bleaching in the post-graduation courses, they were all encouraged to offer this cosmetic dentistry procedure with the opportunity of obtaining a beautiful and healthy smile, thus assuring the belief of the Caucasian racial aesthetic superiority. This study make us

  10. Wastewater and Sludge Reuse Management in Agriculture

    Directory of Open Access Journals (Sweden)

    Ioannis K. Kalavrouziotis

    2016-08-01

    Full Text Available Huge quantities of treated wastewater (TMWW and biosolids (sludge are produced every day all over the world, which exert a strong pressure on the environment. An important question that is raised is “what to do with them?”.An effort is put by the scientific community to eliminate the concept of “waste” and to replace it with the concept of “recycling of resources”, by means of effective management, which does not concern only the users, but all the other groups involved in the problem, such as facility administrators, operations, politicians, scientific community and the general population. Sludge concentration data showed that there exist 516 chemicals in biosolids which create a serious health risk. It is pointed out that this risk will be greatly exacerbated by chemical toxins present in the sludge which can predispose skin to infection by pathogens. Consequently, the need for science-based policies are necessary to effectively protect public health. The risk assessment due to sludge, is difficult to evaluate of due to the large number of unknown interactions involved. People living near the sludge application sites may suffer from such abnormalities as: eye, nose, and throat irritation, gastrointestinal abnormalities, as nausea, vomiting, diarrhea, including cough, difficulty in breathing, sinus congestion, skin infection and sores. Many problems seem to be related to biosolid and wastewater application in agriculture, which should be solved. A universal one, acknowledged as an “international health crisis” is the resistance of pathogens to antibiotics and to the evolution of multidrug resistance of bacteria”. Certain anthropogenically created environments have been identified as major sources of multidrug resistance bacteria such as in water treatment plants, concentrated animal feeding operations etc. All these, and many other health problems, render the safety of sludge and biosolid and wastewater agricultural reuse, for

  11. Data reuse and the open data citation advantage.

    Science.gov (United States)

    Piwowar, Heather A; Vision, Todd J

    2013-01-01

    Background. Attribution to the original contributor upon reuse of published data is important both as a reward for data creators and to document the provenance of research findings. Previous studies have found that papers with publicly available datasets receive a higher number of citations than similar studies without available data. However, few previous analyses have had the statistical power to control for the many variables known to predict citation rate, which has led to uncertain estimates of the "citation benefit". Furthermore, little is known about patterns in data reuse over time and across datasets. Method and Results. Here, we look at citation rates while controlling for many known citation predictors and investigate the variability of data reuse. In a multivariate regression on 10,555 studies that created gene expression microarray data, we found that studies that made data available in a public repository received 9% (95% confidence interval: 5% to 13%) more citations than similar studies for which the data was not made available. Date of publication, journal impact factor, open access status, number of authors, first and last author publication history, corresponding author country, institution citation history, and study topic were included as covariates. The citation benefit varied with date of dataset deposition: a citation benefit was most clear for papers published in 2004 and 2005, at about 30%. Authors published most papers using their own datasets within two years of their first publication on the dataset, whereas data reuse papers published by third-party investigators continued to accumulate for at least six years. To study patterns of data reuse directly, we compiled 9,724 instances of third party data reuse via mention of GEO or ArrayExpress accession numbers in the full text of papers. The level of third-party data use was high: for 100 datasets deposited in year 0, we estimated that 40 papers in PubMed reused a dataset by year 2, 100 by

  12. Dynamic optimization of a dead-end filtration trajectory: non-ideal cake filtration

    NARCIS (Netherlands)

    Blankert, B.; Kattenbelt, C.; Betlem, Bernardus H.L.; Roffel, B.

    2007-01-01

    A control strategy aimed at minimizing energy consumption is formulated for non-ideal dead-end cake filtration with an inside-out hollow fiber ultrafiltration membrane system. The non-ideal behavior was assumed to originate from cake compression, non-linear cake resistance and a variable pump

  13. Dynamic optimization of a dead-end filtration trajectory : Non-ideal cake filtration

    NARCIS (Netherlands)

    Blankert, Bastiaan; Kattenbelt, Carolien; Betlem, Ben H.L.; Roffel, Brian

    2007-01-01

    A control strategy aimed at minimizing energy consumption is formulated for non-ideal dead-end cake filtration with an inside-out hollow fiber ultrafiltration membrane system. The non-ideal behavior was assumed to originate from cake compression, non-linear cake resistance and a variable pump

  14. Riverbed Clogging and Sustainability of Riverbank Filtration

    Directory of Open Access Journals (Sweden)

    Thomas Grischek

    2016-12-01

    Full Text Available Clogging refers to a reduction of riverbed hydraulic conductivity. Due to difficulties in determining the thickness of the clogging layer, the leakage coefficient (L is introduced and used to quantify the recoverable portion of bank filtrate. L was determined at several riverbank filtration (RBF sites in field tests and using an analytical solution. Results were compared with data from similar experiments in the early 1970s and 1991–1993. In the 1980s, severe river water pollution in conjunction with high water abstraction led to partly unsaturated conditions beneath the riverbed. A leakage coefficient L of 5 × 10−7 s−1 was determined. After water quality improvement, L increased to 1–1.5 × 10−6 s−1. An alternative, cost and time efficient method is presented to estimate accurate leakage coefficients. The analytical solution is based on groundwater level monitoring data from observation wells next to the river, which can later feed into numerical models. The analytical approach was able to reflect long-term changes as well as seasonal variations. Recommendations for its application are given based on experience.

  15. Update on the glomerular filtration barrier.

    Science.gov (United States)

    Jarad, George; Miner, Jeffrey H

    2009-05-01

    The nephrology community lacks a unified view of protein sieving through the glomerular capillary wall. The glomerular capillary wall consists of three distinct but closely interacting layers: the fenestrated endothelium, with its glycocalyx; the podocytes, with their interdigitated foot processes and slit diaphragms; and the intervening glomerular basement membrane. Proteinuria is associated with abnormalities in any one layer, suggesting that each contributes to the glomerular filtration barrier (GFB). Proteinuria can also be induced in the context of a normal glomerular capillary wall. Here, we review some classic studies as well as some newer concepts and present competing hypotheses about the GFB. Two almost forgotten concepts have recently emerged. One group has challenged the exquisite selectivity of the GFB to albumin and suggested that proteinuria is the result of abnormal tubular uptake. There has also been a reemphasis on diffusion through the glomerular basement membrane as the driving force behind macromolecular filtration. New evidence suggests that the endothelial glycocalyx is an important charge-selective barrier. We suggest viewing the GFB as a dynamic rather than as a rigid barrier, requiring three healthy layers and a hemodynamic steady state. Multiple challenges to studying the endothelium, the tubular handling of albumin, and the role of hemodynamic forces will require new tools, new hypotheses, and open minds.

  16. Renal filtration function in patients with gout

    Directory of Open Access Journals (Sweden)

    N. N. Kushnarenko

    2016-01-01

    Full Text Available Aim. To study circadian blood pressure (BP profile in patients with gout depending on the presence of arterial hypertension (HT and their relationship to the renal filtration function.Material and methods. Patients with gout (n=87 were included into the study. All the patients underwent ambulatory BP monitoring (ABPM with the assessment of circadian BP profile, determination of uric acid serum levels, glomerular filtration rate (GFR was evaluated by CKD-EPI method. Depending on GFR level, all the patients were divided into 2 groups - with renal dysfunction or without one.Results. ABPM revealed circadian BP dysregulation in 55% of gout patients both with HT and without HT. Chronic kidney disease (CKD was revealed in 72.4% of male patients, with the prevalence in patients with HT (76.6 vs 61%; p<0.001. Correlations between uric acid levels and some ABPM indicators and GFR were determined.Conclusion. Obtained data suggest the contribution of hyperuricemia in disorders of systemic and renal hemodynamics, leading to the early development of CKD.

  17. Electrospinning of nanofibers for filtration media

    Science.gov (United States)

    Park, Hyoungjun

    Since particulate impurity is regarded as the primary cause of lung diseases, purification of air has been a crucial issue. Filtration is the most conventional method to obtain clean air, whereby particulate matter is collected on a fibrous media. The use of fibrous filters is prevalent because of their high filtration efficiency and low pressure drop. Fibrous filters were fabricated via the electrospinning process which can be used to produce continuous submicron-diameter sized fibers. Polyacrylonitrile (PAN) nanofibers with a mean fiber diameter of 224 nm were electrospun to form fibermats. Filtration tests on fibermats of PAN were conducted to confirm that filters of thinner fibers result in higher collection efficiencies and lower pressure drops than that of thicker fibers as predicted by the theoretical filtration mechanism. Results showed that electrospun PAN nanofibermats had a superior quality factor of 0.067+/-0 compared to 0.031+/-0.001 by the current state-of-the-art microfiber-based high particulate air (HEPA) filtration media. The verified theory implies that nanofibermats of other types of materials could also be considered as promising filtration media since filtration performance is independent of the material used. As materials for advanced next-generation filtration media, ceramics are favored over polymeric materials due to their robustness against environmental factors such as ultraviolet rays, abrasive particles, and high temperature all of which degrade and damage the fibrous structure. Amidst various ceramic materials, the anatase phase of TiO2 was selected due to its mechanical property and versatility as a photocatalyst and microwave-absorbing material. Anatase TiO2 fibers were fabricated by electrospinning followed by heat treatment at 500°C for 3 hours. However, early precipitation or gelation of the organic solvent-based TiO2 sol posed a practical challenge in the sample preparation. In order to enhance stability of the precursor sol, a

  18. Silica incorporated membrane for wastewater based filtration

    Science.gov (United States)

    Fernandes, C. S.; Bilad, M. R.; Nordin, N. A. H. M.

    2017-10-01

    Membrane technology has long been applied for waste water treatment industries due to its numerous advantages compared to other conventional processes. However, the biggest challenge in pressure driven membrane process is membrane fouling. Fouling decreases the productivity and efficiency of the filtration, reduces the lifespan of the membrane and reduces the overall efficiency of water treatment processes. In this study, a novel membrane material is developed for water filtration. The developed membrane incorporates silica nanoparticles mainly to improve its structural properties. Membranes with different loadings of silica nanoparticles were applied in this study. The result shows an increase in clean water permeability and filterability of the membrane for treating activated sludge, microalgae solution, secondary effluent and raw sewage as feed. Adding silica into the membrane matrix does not significantly alter contact angle and membrane pore size. We believe that silica acts as an effective pore forming agent that increases the number of pores without significantly altering the pore sizes. A higher number of small pores on the surface of the membrane could reduce membrane fouling because of a low specific loading imposed to individual pores.

  19. EM Task 9 - Centrifugal Membrane Filtration

    International Nuclear Information System (INIS)

    Stevens, B.G.; Stepan, D.J.; Hetland, M.D.

    1998-01-01

    This project is designed to establish the utility of a novel centrifugal membrane filtration technology for the remediation of liquid mixed waste streams at US Department of Energy (DOE) facilities in support of the DOE Environmental Management (EM) program. The Energy and Environmental Research Center (EERC) has teamed with SpinTek Membrane Systems, Inc., a small business and owner of the novel centrifugal membrane filtration technology, to establish the applicability of the technology to DOE site remediation and the commercial viability of the technology for liquid mixed waste stream remediation. The technology is a uniquely configured process that makes use of ultrafiltration and centrifugal force to separate suspended and dissolved solids from liquid waste streams, producing a filtered water stream and a low-volume contaminated concentrate stream. This technology has the potential for effective and efficient waste volume minimization, the treatment of liquid tank wastes, the remediation of contaminated groundwater plumes, and the treatment of secondary liquid waste streams from other remediation processes, as well as the liquid waste stream generated during decontamination and decommissioning activities

  20. Glomerular Filtration Rate is Unchanged By Ultramarathon.

    Science.gov (United States)

    Wołyniec, Wojciech; Ratkowski, Wojciech; Kasprowicz, Katarzyna; Jastrzębski, Zbigniew; Małgorzewicz, Sylwia; Witek, Konrad; Grzywacz, Tomasz; Żmijewski, Piotr; Renke, Marcin

    2017-12-27

    Acute kidney injury (AKI) is reported as a common complication of marathon and ultramarathon running. In previous studies AKI was diagnosed on the basis of the creatinine level in serum and estimated glomerular filtration rate (eGFR). In the present study we calculated eGFR and also measured creatinine clearance after every 25 km of a 100 km run. 20 healthy, amateur runners (males, mean age 40.75 ± 7.15 years, mean weight 76.87 ± 8.39 kg) took part in a 100 km run on a track. Blood and urine were collected before the run, after every 25 km and 12 hours after the run. 17 runners completed the study. There was increase in creatinine, urea and uric acid observed after 100 km (p AKIN) criteria of AKI. The eGFR according to the MDRD (modification of diet in renal disease), CKD-EPI (chronic kidney disease epidemiology collaboration) and Cockcroft-Gault formulas was significantly decreased after the run (p < 0.05). Otherwise, creatinine clearance calculated from creatinine level in both serum and urine remained stable. In contrast to the majority of previous studies, we did not observe any decrease in the kidney function during an ultramarathon. In this study the creatinine clearance, which is the best routine laboratory method to determine glomerular filtration rate was used. There is no evidence that long running is harmful for kidney.

  1. Filtration Systems Design for Universal Oils in Agricultural Tractors

    Directory of Open Access Journals (Sweden)

    R. Majdan

    2017-12-01

    Full Text Available Three filtration systems using the tractor hydraulic circuit were proposed and verified during the tractors operation. Using the tractor-implement hydraulic system and filter body with accessories the universally useful filtration systems were designed. The designed filtration systems are the second stage of universal oil filtration whereas the first stage is the standard tractor filter. The decrease in the content of iron reached the values 25.53 %, 32.95 % and 41.55 % and the average decrease in oil contamination characterized by average value of decrease in content of iron, copper and silicium reached values 24.3 %, 24.7 % and 35.53 % in dependence on the filtration system and an oil contamination level. The decrease in contamination level verified the ability of designed filtration systems for agricultural tractors.

  2. Vision-related quality of life following glaucoma filtration surgery.

    Science.gov (United States)

    Hirooka, Kazuyuki; Nitta, Eri; Ukegawa, Kaori; Tsujikawa, Akitaka

    2017-05-12

    To evaluate vision-related quality of life (VR-QOL) following glaucoma filtration surgery. A total of 103 glaucoma patients scheduled to undergo glaucoma filtration surgery. Prior to and at three months after glaucoma filtration surgery, trabeculectomy or EX-PRESS, all patients completed the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25). A total of 48 patients underwent combined cataract and filtration surgery. The clinical data collected pre- and postoperatively included best-corrected visual acuity (BCVA) and intraocular pressure (IOP). The IOP decreased significantly from 19.0 ± 8.1 mmHg to 9.7 ± 3.9 mmHg (P glaucoma filtration surgery by itself did not decrease the VR-QOL in glaucoma patients, there was significant improvement in the VR-QOL after the patients underwent combined cataract and glaucoma filtration surgery.

  3. METHODICAL BASES OF ESTIMATION GLOMERULAR FILTRATION RATE IN UROLOGICAL PRACTICE

    Directory of Open Access Journals (Sweden)

    M. M. Batiushin

    2017-01-01

    Full Text Available The article presents a review of methodological issues of estimation of glomerular filtration rate in urologic practice. Author examine the current international and national recommendations, in particular by KDIGO, the recommendations of the scientific society of nephrologists of Russia, Association of urologists of Russia, the results of comparative analysis of different methods of assessing glomerular filtration rate. It is shown that the currently calculated methods of assessment of glomerular filtration rate have advantages over technique of clearance. The advantages and disadvantages of methods for calculating glomerular filtration rate by the formula of Cockcroft-Gault and MDRD. The author lists the pathological conditions in urological practice, in which there is a need to assess glomerular filtration rate, given nomograms and links to online calculators for quick and easy calculation of glomerular filtration rate.

  4. In-Water Hull Cleaning & Filtration System

    Science.gov (United States)

    George, Dan

    2015-04-01

    Dan George R & D Mining Technology LinkedIn GRD Franmarine have received the following prestigious awards in 2014 for their research & development of an in-water hull cleaning and filtration system "The Envirocart: Golden Gecko Award for Environmental Excellence; WA Innovator of the Year - Growth Sector; Department of Fisheries - Excellence in Marine Biosecurity Award - Innovation Category; Lloyd's List Asia Awards - Environmental Award; The Australian Innovation Challenge - Environment, Agriculture and Food Category; and Australian Shipping and Maritime Industry Award - Environmental Transport Award. The Envirocart developed and patented by GRD Franmarine is a revolutionary new fully enclosed capture and containment in-water hull cleaning technology. The Envirocart enables soft Silicon based antifouling paints and coatings containing pesticides such as Copper Oxide to be cleaned in situ using a contactless cleaning method. This fully containerised system is now capable of being deployed to remote locations or directly onto a Dive Support Vessel and is rated to offshore specifications. This is the only known method of in-water hull cleaning that complies with the Department of Agriculture Fisheries and Forestry (DAFF) and Department of Fisheries WA (DoF) Guidelines. The primary underwater cleaning tool is a hydraulically powered hull cleaning unit fitted with rotating discs. The discs can be fitted with conventional brushes for glass or epoxy based coatings or a revolutionary new patented blade system which can remove marine biofouling without damaging the antifouling paint (silicone and copper oxide). Additionally there are a patented range of fully enclosed hand cleaning tools for difficult to access niche areas such as anodes and sea chests, providing an innovative total solution that enables in-water cleaning to be conducted in a manner that causes no biological risk to the environment. In full containment mode or when AIS are present, material is pumped

  5. Impairment in glomerular filtration rate or glomerular filtration barrier and occurrence of stroke.

    Science.gov (United States)

    Ovbiagele, Bruce

    2008-07-01

    Chronic kidney disease (CKD) is associated with substantial burden and is a strong risk factor for cardiovascular disease. However, data on the relationship between CKD and stroke are few and are limited by unreliable or inadequate assessment of renal function. To properly assess the relationship between renal insufficiency and stroke in stroke survivors in the United States by simultaneously examining the effect of guideline-recommended indices of renal disease that measure glomerular filtration rate (creatinine clearance) and glomerular filtration barrier (proteinuria). Cross sectional. Nationally representative survey of the United States. Participants aged 55 or older who participated in the National Health and Nutrition Examination Survey from 1999 to 2004. Indices of renal disease that measure glomerular filtration rate (creatinine clearance) and glomerular filtration barrier (microalbuminuria). Of 6382 adults who met inclusion criteria, 5624 (88%) had full and complete data, of which 414 (6%) reported having had a stroke. Stroke survivors were older and more likely to have CKD, diabetes, hypertension, coronary artery disease, elevated blood pressure, increased glycohemoglobin concentration, and lower hematocrit compared with respondents who did not report stroke. Multivariate models showed that microalbuminuria (odds ratio, 1.51; 95% confidence interval, 1.02-2.24), decreased glomerular filtration rate (odds ratio, 1.93; 95% confidence interval, 1.28-2.91), and stage 3 CKD (odds ratio, 2.09; 95% confidence interval, 1.38-3.16) were significantly associated with stroke. Stroke is independently associated with impairment in structure and function of the glomerulus, which supports the need to consider screening patients with stroke for CKD and to simultaneously assess for both indices of renal disease.

  6. A method for defleshing human remains using household bleach.

    Science.gov (United States)

    Mann, Robert W; Berryman, Hugh E

    2012-03-01

    Medical examiners and forensic anthropologists are often faced with the difficult task of removing soft tissue from the human skeleton without damaging the bones, teeth and, in some cases, cartilage. While there are a number of acceptable methods that can be used to remove soft tissue including macerating in water, simmering or boiling, soaking in ammonia, removing with scissors, knife, scalpel or stiff brush, and dermestid beetles, each has its drawback in time, safety, or potential to damage bone. This technical report using the chest plate of a stabbing victim presents a safe and effective alternative method for removing soft tissue from human remains, in particular the chest plate, following autopsy, without damaging or separating the ribs, sternum, and costal cartilage. This method can be used to reveal subtle blunt force trauma to bone, slicing and stabbing injuries, and other forms of trauma obscured by overlying soft tissue. Despite the published cautionary notes, when done properly household bleach (3-6% sodium hypochlorite) is a quick, safe, and effective method for examining cartilage and exposing skeletal trauma by removing soft tissue from human skeletal remains. 2011 American Academy of Forensic Sciences. Published 2011. This article is a U.S. Government work and is in the public domain in the U.S.A.

  7. Biological and advanced treatment of sulfate pulp bleaching effluents

    International Nuclear Information System (INIS)

    Çeçen, F.; Urban, W.; Haberl, R.

    1992-01-01

    Spent bleaching effluents (from chlorination (C) and extraction (E) stages) of a sulfate pulp mill were subjected to bench-scale biological and advanced treatment. Although > 90 % of the influent BOD 5 could be removed in an activated sludge process, the effluent still contained high amounts of resistant substances. The maximum COD removal was about 50 %; the removal rates achieved in the parameters TOC, DOC, AOX, SAK (254 nm) were even lower. The biological treatment led to an increase in color (436 nm) up to 40 %. The biologically pretreated effluent was further treated by ozone or ozone/irradiation. The DOC, COD, color (436 nm), SAK (254 nm) and AOX removal rates amounted to 61 %, 81 %, 98 %, 92 % and 92 %, respectively. These methods led simultaneously to an increase in biological biodegradability as reflected by an increase in BOD 5 . A comparison of the results obtained for raw and biologically pretreated wastewaters showed that biodegradable substances should first be removed from the wastewater since otherwise the effectiveness of these methods decreased. The coagulation/flocculation of biologically pretreated effluent showed that FeCl3 was the most effective coagulant and that removal rates > 90 % could be achieved. The treatment with various powder activated carbons showed that a dosage of 10 g/l was required to achieve elimination rates > 90 % in the parameters DOC, COD, color (436 nm) and SAK (254 nm). Adsorption isotherms were developed for every activated carbon and adsorption constants were calculated. (author)

  8. Resilience and climate change: lessons from coral reefs and bleaching in the Western Indian Ocean

    Science.gov (United States)

    Obura, David O.

    2005-05-01

    The impact of climate change through thermal stress-related coral bleaching on coral reefs of the Western Indian Ocean has been well documented and is caused by rising sea water temperatures associated with background warming trends and extreme climate events. Recent studies have identified a number of factors that may reduce the impact of coral bleaching and mortality at a reef or sub-reef level. However, there is little scientific consensus as yet, and it is unclear how well current science supports the immediate needs of management responses to climate change. This paper provides evidence from the Western Indian Ocean in support of recent hypotheses on coral and reef vulnerability to thermal stress that have been loosely termed 'resistance and resilience to bleaching'. The paper argues for a more explicit definition of terms, and identifies three concepts affecting coral-zooxanthellae holobiont and reef vulnerability to thermal stress previously termed 'resistance to bleaching': 'thermal protection', where some reefs are protected from the thermal conditions that induce bleaching and/or where local physical conditions reduce bleaching and mortality levels; 'thermal resistance', where individual corals bleach to differing degrees to the same thermal stress; and 'thermal tolerance', where individual corals suffer differing levels of mortality when exposed to the same thermal stress. 'Resilience to bleaching' is a special case of ecological resilience, where recovery following large-scale bleaching mortality varies according to ecological and other processes. These concepts apply across multiple levels of biological organization and temporal and spatial scales. Thermal resistance and tolerance are genetic properties and may interact with environmental protection properties resulting in phenotypic variation in bleaching and mortality of corals. The presence or absence of human threats and varying levels of reef management may alter the influence of the above factors

  9. Filtration in the Use of Individual Water Purification Devices

    National Research Council Canada - National Science Library

    Lundquist, Arthur; Clarke, Steven; Bettin, William

    2006-01-01

    .... Understanding the ability of filtration to reduce disease-causing microorganisms in water is important in protecting Soldiers, who are considering using this technology, from acute health threats...

  10. Software Reuse Success Strategy Model: An Empirical Study of Factors Involved in the Success of Software Reuse in Information System Development

    Science.gov (United States)

    Tran, Kiet T.

    2012-01-01

    This study examined the relationship between information technology (IT) governance and software reuse success. Software reuse has been mostly an IT problem but rarely a business one. Studies in software reuse are abundant; however, to date, none has a deep appreciation of IT governance. This study demonstrated that IT governance had a positive…

  11. Does the water reuse affect the fish growth, welfare quality?

    Directory of Open Access Journals (Sweden)

    Štěpán Lang

    2012-01-01

    Full Text Available The fish production in aquaculture is growing from year to year. However capacities of current aquaculture facilities are limited. So the need of intensification of old facilities and building new intensive facilities is obvious. The high intensity of fish culture generates some questions. Could water reuse affect fish growth, welfare, health or quality of final product? A lot of research was performed for this issue but just a few works compared water reuse systems (RAS versus flow thru systems (FTS. A problem with CO2 oversaturation was solved by shallow diffusers. Fin erosion seems to be a problem of high stocking density and system hygienic but it is not related directly to water reuse. A few papers were written about biochemical blood stress markers but it was mostly aimed to acute crowding or changes were found at extreme stocking densities over 124 kg.m3 for rainbow trout and 70 kg.m3 for sea bass. The fish are able to accustom to increased noise produced by RAS equipment very fast so it don’t affect fish negatively. There wasn’t found any prove of main water reuse to fish influence in the available literature. All results indicates that if the ecological parameters are kept in natural range for the fish reared in RAS, there is no negative effect of water reuse on fish.

  12. Nearshore Turbid-Zone Corals Exhibit High Bleaching Tolerance on the Great Barrier Reef Following the 2016 Ocean Warming Event

    OpenAIRE

    Morgan, Kyle M.; Perry, Chris T.; Johnson, Jamie A.; Smithers, Scott G.

    2017-01-01

    High sea surface temperatures (SSTs) on the Great Barrier Reef (GBR) during summer 2015/2016 caused extensive coral bleaching, with aerial and in-water surveys confirming high (but variable) bleaching-related coral mortality. In contrast, bleaching impacts on nearshore turbid-zone reefs, traditionally considered more “marginal” coral habitats, remain poorly documented. This is because rapid ecological surveys are difficult in these turbid water settings, and baseline coral community data from...

  13. Cell death and degeneration in the symbiotic\\ud dinoflagellates of the coral Stylophora pistillata\\ud during bleaching

    OpenAIRE

    Franklin, Daniel J.; Hoegh-Guldberg, O.; Jones, R.J.; Berges , John A.

    2004-01-01

    Rising sea temperatures are increasing the incidences of mass coral bleaching (the dissociation\\ud of the coral–algal symbiosis) and coral mortality. In this study, the effects of bleaching\\ud (induced by elevated light and temperature) on the condition of symbiotic dinoflagellates (Symbiodinium\\ud sp.) within the tissue of the hard coral Stylophora pistillata (Esper) were assessed using a suite\\ud of techniques. Bleaching of S. pistillata was accompanied by declines in the maximum potential\\...

  14. Reuse of Textile Dyeing Effluents Treated with Coupled Nanofiltration and Electrochemical Processes

    Directory of Open Access Journals (Sweden)

    Valentina Buscio

    2016-06-01

    Full Text Available The reactive dye Cibacron Yellow S-3R was selected to evaluate the feasibility of combining nanofiltration membranes with electrochemical processes to treat textile wastewater. Synthetic dyeing effluents were treated by means of two nanofiltration membranes, Hydracore10 and Hydracore50. Up to 98% of dye removal was achieved. The influence of salt concentration and pH on membrane treatment was studied. The best dye removal yield was achieved at pH 3 in the presence of 60 g/L of NaCl. After the membrane filtration, the concentrate containing high dye concentration was treated by means of an electrochemical process at three different current densities: 33, 83, and 166 mA/cm2. Results showed a lineal relationship between treatment time and applied current density. Both permeates and electrochemically-decoloured effluents were reused in new dyeing processes (100% of permeate and 70% of decoloured concentrates. Dyed fabrics were evaluated with respect to original dyeing. Colour differences were found to be into the acceptance range.

  15. Massive hard coral loss after a severe bleaching event in 2010 at Los Roques, Venezuela

    Directory of Open Access Journals (Sweden)

    Carolina Bastidas

    2012-03-01

    Full Text Available Thermal anomalies have become more severe, frequent and well-documented across the Caribbean for the past 30 years. This increase in temperature has caused coral bleaching resulting in reef decline. At Los Roques National Park, Venezuela, temperature has been monitored at four reef sites. In mid-September 2010, seawater temperature reached 30.85°C at 5 m depth in Los Roques, an archipelago only slightly affected by previous bleaching events. For example, bleaching in Los Roques in 2005 was mild compared to the rest of the Caribbean and to the results in this study. In 2010, seawater temperatures remained above 29.0°C from mid-August until the first week of November, resulting in +16 Degree Heating Weeks by that time. Our annual survey of four reef sites indicated that 72% of 563 scleractinian colonies were partial or totally bleached (white or pale (discolored in October 2010. In February 2011, there were still 46% of coral colonies affected; but most of them were pale and only 2% were bleached. By February, coral cover had declined 4 to 30% per transect, with a mean of 14.3%. Thus, mean coral cover dropped significantly from 45 to 31% cover (a 34% reduction. In addition to bleaching, corals showed a high prevalence (up to 16% of black band disease in October 2010 and of white plague (11% in February 2011. As a consequence, coral mortality is expected to be larger than reported here. Reef surveys since 2002 and personal observations for more than 20 years indicated that this bleaching event and its consequences in Los Roques have no precedent. Our results suggest that reef sites with no previous record of significant deterioration are more likely to become affected by thermal anomalies. However, this archipelago is relatively unaffected by local anthropogenic disturbance and has a high coral recruitment, which may contribute to its recovery

  16. Effects of modeled tropical sea surface temperature variability on coral reef bleaching predictions

    Science.gov (United States)

    van Hooidonk, R.; Huber, M.

    2012-03-01

    Future widespread coral bleaching and subsequent mortality has been projected using sea surface temperature (SST) data derived from global, coupled ocean-atmosphere general circulation models (GCMs). While these models possess fidelity in reproducing many aspects of climate, they vary in their ability to correctly capture such parameters as the tropical ocean seasonal cycle and El Niño Southern Oscillation (ENSO) variability. Such weaknesses most likely reduce the accuracy of predicting coral bleaching, but little attention has been paid to the important issue of understanding potential errors and biases, the interaction of these biases with trends, and their propagation in predictions. To analyze the relative importance of various types of model errors and biases in predicting coral bleaching, various intra- and inter-annual frequency bands of observed SSTs were replaced with those frequencies from 24 GCMs 20th century simulations included in the Intergovernmental Panel on Climate Change (IPCC) 4th assessment report. Subsequent thermal stress was calculated and predictions of bleaching were made. These predictions were compared with observations of coral bleaching in the period 1982-2007 to calculate accuracy using an objective measure of forecast quality, the Peirce skill score (PSS). Major findings are that: (1) predictions are most sensitive to the seasonal cycle and inter-annual variability in the ENSO 24-60 months frequency band and (2) because models tend to understate the seasonal cycle at reef locations, they systematically underestimate future bleaching. The methodology we describe can be used to improve the accuracy of bleaching predictions by characterizing the errors and uncertainties involved in the predictions.

  17. Opposite latitudinal gradients in projected ocean acidification and bleaching impacts on coral reefs.

    Science.gov (United States)

    van Hooidonk, Ruben; Maynard, Jeffrey Allen; Manzello, Derek; Planes, Serge

    2014-01-01

    Coral reefs and the services they provide are seriously threatened by ocean acidification and climate change impacts like coral bleaching. Here, we present updated global projections for these key threats to coral reefs based on ensembles of IPCC AR5 climate models using the new Representative Concentration Pathway (RCP) experiments. For all tropical reef locations, we project absolute and percentage changes in aragonite saturation state (Ωarag) for the period between 2006 and the onset of annual severe bleaching (thermal stress >8 degree heating weeks); a point at which it is difficult to believe reefs can persist as we know them. Severe annual bleaching is projected to start 10-15 years later at high-latitude reefs than for reefs in low latitudes under RCP8.5. In these 10-15 years, Ωarag keeps declining and thus any benefits for high-latitude reefs of later onset of annual bleaching may be negated by the effects of acidification. There are no long-term refugia from the effects of both acidification and bleaching. Of all reef locations, 90% are projected to experience severe bleaching annually by 2055. Furthermore, 5% declines in calcification are projected for all reef locations by 2034 under RCP8.5, assuming a 15% decline in calcification per unit of Ωarag. Drastic emissions cuts, such as those represented by RCP6.0, result in an average year for the onset of annual severe bleaching that is ~20 years later (2062 vs. 2044). However, global emissions are tracking above the current worst-case scenario devised by the scientific community, as has happened in previous generations of emission scenarios. The projections here for conditions on coral reefs are dire, but provide the most up-to-date assessment of what the changing climate and ocean acidification mean for the persistence of coral reefs. © 2013 John Wiley & Sons Ltd.

  18. Effect of bleaching on mercury release from amalgam fillings and antioxidant enzyme activities: a pilot study.

    Science.gov (United States)

    Cakir, Filiz Yalcin; Ergin, Esra; Gurgan, Sevil; Sabuncuoglu, Suna; Arpa, Cigdem Sahin; Tokgoz, İlknur; Ozgunes, Hilal; Kiremitci, Arlin

    2015-01-01

    The aim of this pilot clinical study was to determine the mercury release from amalgam fillings and antioxidant enzyme activities (Superoxide Dismutase [SOD] and Catalase[CAT] ) in body fluids after exposure to two different vital tooth bleaching systems. Twenty eight subjects with an average age of 25.6 years (18-41) having at least two but not more than four Class II amalgam fillings on each quadrant arch in the mouth participated in the study. Baseline concentrations of mercury levels in whole blood, urine, and saliva were measured by a Vapor Generation Accessory connected to an Atomic Absorption Spectrometer. Erythrocyte enzymes, SOD, and CAT activities in blood were determined kinetically. Subjects were randomly assigned to two groups of 14 volunteers. Group 1 was treated with an at-home bleaching system (Opalescence PF 35% Carbamide Peroxide, Ultradent), and Group 2 was treated with a chemically activated office bleaching system (Opalescence Xtra Boost 38% Hydrogen Peroxide, Ultradent) according to the manufacturer's recommendations. Twenty-four hours after bleaching treatments, concentrations of mercury and enzymes were remeasured. There were no significant differences on mercury levels in blood, urine, and saliva before and after bleaching treatments (p > 0.05). No differences were also found in the level of antioxidant enzyme activities (SOD and CAT) before and after treatments (p > 0.05). Mercury release did not affect the enzyme activities (p > 0.05). Bleaching treatments either office or home did not affect the amount of mercury released from amalgam fillings in blood, urine, and saliva and the antioxidant-enzyme activities in blood. Bleaching treatments with the systems tested in this pilot study have no deleterious effect on the mercury release from amalgam fillings and antioxidant enzymes in body fluids. © 2014 Wiley Periodicals, Inc.

  19. Surviving coral bleaching events: porites growth anomalies on the Great Barrier Reef.

    Science.gov (United States)

    Cantin, Neal E; Lough, Janice M

    2014-01-01

    Mass coral bleaching affected large parts of the Great Barrier Reef (GBR) in 1998 and 2002. In this study, we assessed if signatures of these major thermal stress events were recorded in the growth characteristics of massive Porites colonies. In 2005 a suite of short (reefs in the central GBR (18-19°S) that have documented observations of widespread bleaching. Sites included inshore (Nelly Bay, Pandora Reef), annually affected by freshwater flood events, midshelf (Rib Reef), only occasionally affected by freshwater floods and offshore (Myrmidon Reef) locations primarily exposed to open ocean conditions. Annual growth characteristics (extension, density and calcification) were measured in 144 cores from 79 coral colonies and analysed over the common 24-year period, 1980-2003. Visual examination of the annual density bands revealed growth hiatuses associated with the bleaching years in the form of abrupt decreases in annual linear extension rates, high density stress bands and partial mortality. The 1998 mass-bleaching event reduced Porites calcification by 13 and 18% on the two inshore locations for 4 years, followed by recovery to baseline calcification rates in 2002. Evidence of partial mortality was apparent in 10% of the offshore colonies in 2002; however no significant effects of the bleaching events were evident in the calcification rates at the mid shelf and offshore sites. These results highlight the spatial variation of mass bleaching events and that all reef locations within the GBR were not equally stressed by the 1998 and 2002 mass bleaching events, as some models tend to suggest, which enabled recovery of calcification on the GBR within 4 years. The dynamics in annual calcification rates and recovery displayed here should be used to improve model outputs that project how coral calcification will respond to ongoing warming of the tropical oceans.

  20. Surviving coral bleaching events: porites growth anomalies on the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Neal E Cantin

    Full Text Available Mass coral bleaching affected large parts of the Great Barrier Reef (GBR in 1998 and 2002. In this study, we assessed if signatures of these major thermal stress events were recorded in the growth characteristics of massive Porites colonies. In 2005 a suite of short (<50 cm cores were collected from apparently healthy, surviving Porites colonies, from reefs in the central GBR (18-19°S that have documented observations of widespread bleaching. Sites included inshore (Nelly Bay, Pandora Reef, annually affected by freshwater flood events, midshelf (Rib Reef, only occasionally affected by freshwater floods and offshore (Myrmidon Reef locations primarily exposed to open ocean conditions. Annual growth characteristics (extension, density and calcification were measured in 144 cores from 79 coral colonies and analysed over the common 24-year period, 1980-2003. Visual examination of the annual density bands revealed growth hiatuses associated with the bleaching years in the form of abrupt decreases in annual linear extension rates, high density stress bands and partial mortality. The 1998 mass-bleaching event reduced Porites calcification by 13 and 18% on the two inshore locations for 4 years, followed by recovery to baseline calcification rates in 2002. Evidence of partial mortality was apparent in 10% of the offshore colonies in 2002; however no significant effects of the bleaching events were evident in the calcification rates at the mid shelf and offshore sites. These results highlight the spatial variation of mass bleaching events and that all reef locations within the GBR were not equally stressed by the 1998 and 2002 mass bleaching events, as some models tend to suggest, which enabled recovery of calcification on the GBR within 4 years. The dynamics in annual calcification rates and recovery displayed here should be used to improve model outputs that project how coral calcification will respond to ongoing warming of the tropical oceans.

  1. Bleaching and mortality of reef organisms during a warming event in 1995 on the Caribbean coast of Costa Rica

    OpenAIRE

    Jiménez, Carlos

    2016-01-01

    Coral reefs at the Caribbean coast of Costa Rica were affected during a bleaching event associated with the 1995 warming of the Western Caribbean. During doldrum weather in late August 1995, reef organisms at Parque Nacional Cahuita were 62% and 7.4% bleached and dead respectively, whilst 67.6% bleached and 8.2% died in the Refugio Nacional de Vida Silvestre Gandoca-Manzanillo. However, Cahuita had the highest mean number of bleached (257 ± 51.1) and dead (30.5 ± 5.6) colonies in the surveyed...

  2. Effects of the Ratio between Pigment and Bleaching Gel on the Fracture Resistance and Dentin Microhardness of endodontically treated Teeth.

    Science.gov (United States)

    Galloza, Marina Og; Jordão-Basso, Keren Cf; Bandeca, Matheus C; Costa, Samuel O; Borges, Alvaro H; Tonetto, Mateus R; Tirintan, Fabio C; Keine, Kátia C; Kuga, Milton C

    2017-11-01

    The aim of this study was to evaluate the effects of bleaching gel using 35% hydrogen peroxide (HP), associated with red carmine pigment (RC), in the 3:1 or 1:1 ratio, on fracture resistance and dentin microhardness of endodontically treated teeth. A total of 40 lower incisors were endodontically treated and divided into four groups (n = 10), according to the bleaching protocol: G1 (HP3), 35% HP + RC (3:1); G2 (HP1), 35% HP + RC (1:1); G3 (positive), 38% HP; and G4 (negative), unbleached. Four dental bleaching sessions were performed. The dental crowns were restored after the last session and submitted to the fracture resistance test. Totally, 60 specimens from the endodontically treated lower incisor crowns were prepared to evaluate the effects on dentin microhardness. The analysis was measured (in Knoop) prior to and after the last dental bleaching session using similar bleaching protocols. G2 presented the lowest fracture resistance (p 0.05). No difference was observed in the reduction of dentin microhardness among the groups (p > 0.05). A 1:1 ratio (bleaching gel:pigment) caused a significant fracture resistance reduction in relation to the other protocols. No effect on the dentin microhardness reduction was observed. The pigment addition to the bleaching agent accelerates the bleaching chemical reaction. However, no studies have evaluated the ideal proportion to optimize tooth bleaching.

  3. Application of TAED/H2O2 system for low temperature bleaching of crude cellulose extracted from jute fiber

    Science.gov (United States)

    Wen, Zuoqiang; Zou, Linbo; Wang, Weiming

    2018-03-01

    Tetraacetylethylenediamine (TAED) activated hydrogen peroxide system had been applied for bleaching of crude cellulose extracted from jute fiber. Comparing with conventional hydrogen peroxide bleaching system, those results showed that bleaching temperature and time could be effectively reduced, and a preferable whiteness could be produced under faint alkaline condition. And the optimum conditions for activated bleaching system could be summarized as molar ratio of H2O2/TAED 1:0.7, pH 8, pure hydrogen peroxide 0.09 mol/L, temperature 70 °C and time 60min.

  4. In vitro evaluation of the chemical and morphological changes of the enamel surface using different bleaching techniques

    International Nuclear Information System (INIS)

    Mattos, Alessandra de Siervi

    2003-01-01

    'In vitro' evaluation through MEV and EDS of the morphological and chemical changes, respectively, of the bovine enamel, submitted to different bleaching techniques. For the MEV evaluation eighteen apical thirds were pigmented and divided into two parts. One half of each sample was the control and the other half was bleached according to the protocol of each test group (n= 6). Group I - home bleaching with a 10% carbamide peroxide; group II bleaching with 35% hydrogen peroxide and LED; group III - bleaching with 35% hydrogen peroxide with diode laser bleaching. The same procedure was done with the eighteen samples which were analyzed through EDS and which had their buccal surface grinded and polished before the bleaching procedure in order to obtain more precise values of the fraction of calcium and phosphorus. The results showed no morphological changes among the analyzed control halves and the bleached halves. There was not a statistical significant difference about Ca and P values, among the control halves and the bleached halves regarding the chemical components (p< 0,05). (author)

  5. Dynamical Systems, Cytokine Storms, and Blood Filtration

    Science.gov (United States)

    Foster, Glenn; Hubler, Alfred

    2008-03-01

    Various infections and non-infectious diseases can trigger immune cells and the proteins (cytokines) the cells use to communicate with each other to be caught in a positive feedback loop; this ``cytokine storm'' is frequently fatal. By examining the network of cytokine-immune cell interactions we will illustrate why anti-mediator drugs have been generally ineffective in stopping this feedback. A more effective approach may be to try and reduce interactions by dampening many signals at once by filtering the cytokines out of the blood directly (think dialysis). We will argue that feedback on an out of control nonlinear dynamical system is easier to understand than its normal healthy state and apply filtration to a toy model of immune response.

  6. Membraneless water filtration using CO2.

    Science.gov (United States)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick B; Stone, Howard A

    2017-05-02

    Water purification technologies such as microfiltration/ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO 2 . Dissolution of CO 2 into the suspension creates solute gradients that drive phoretic motion of particles. Due to the large diffusion potential generated by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Using the directed motion of particles induced by exposure to CO 2 , we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits low energy consumption, three orders of magnitude lower than conventional microfiltration/ultrafiltration processes, and is essentially free from fouling.

  7. Suitability assessment of grey water quality treated with an upflow-downflow siliceous sand/marble waste filtration system for agricultural and industrial purposes.

    Science.gov (United States)

    Chaabane, Safa; Riahi, Khalifa; Hamrouni, Hédi; Thayer, Béchir Ben

    2017-04-01

    The present study examines the suitability assessment of an upflow-downflow siliceous sand/marble waste filtration system for treatment and reuse of grey water collected from bathrooms of the student residential complex at the Higher Institute of Engineering Medjez El Bab (Tunisia). Once the optimization of grey water pre-treatment system has been determined, the filtration system was operated at different hydraulic loading rate and media filter proportions in order to assess the suitability of treated grey water for irrigational purpose according to salinity hazard, sodium hazard, magnesium hazard, permeability index, water infiltration rate, and widely used graphical methods. Suitability of the treated grey water for industrial purpose was evaluated in terms of foaming, corrosion, and scaling. Under optimal operational conditions, results reveals that treated grey water samples with an upflow-downflow siliceous sand/marble waste filtration system may be considered as a good and an excellent water quality suitable for irrigation purpose. However, treated grey water was found not appropriate for industrial purpose due to high concentrations of calcium and sodium that can generate foaming and scaling harm to boilers. These results suggest that treated grey water with an upflow-downflow siliceous sand/marble waste filtration system would support production when used as irrigation water.

  8. REUSE OF AUTOMOTIVE COMPONENTS FROM DISMANTLED END OF LIFE VEHICLES

    Directory of Open Access Journals (Sweden)

    Piotr NOWAKOWSKI

    2013-12-01

    Full Text Available The problem of recycling end of life automotive vehicles is serious worldwide. It is one of the most important streams of waste in developed countries. It has big importance as recycling potential of raw materials content in automotive vehicles is valuable. Different parts and assemblies after dismantling can also be reused in vehicles where replacement of specific component is necessary. Reuse of the components should be taken into consideration in selecting the vehicles dismantling strategy. It also complies with European Union policy concerning end of life vehicles (ELV. In the paper it is presented systematic approach to dismantling strategies including disassembly oriented on further reuse of components. It is focused on decision making and possible benefits calculation from economic and environmental point of view.

  9. Radiological control criteria for materials considered for recycle and reuse

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Hill, R.L.; Aaberg, R.L.; Wallo, A. III.

    1995-01-01

    Pacific Northwest Laboratory (PNL) is conducting technical analyses to support the U.S. Department of Energy (DOE), Office of Environmental Guidance, Air, Water, and Radiation Division (DOE/EH-232) in developing radiological control criteria for recycling or reuse of metals or equipment containing residual radioactive contamination from DOE operations. The criteria, framed as acceptable concentrations for release of materials for recycling or reuse, are risk-based and were developed through analysis of generic radiation exposure scenarios and pathways. The analysis includes evaluation of relevant radionuclides, potential mechanisms of exposure, and non-health-related impacts of residual radioactivity on electronics and film. The analysis considers 42 key radionuclides that DOE operations are known to generate and that may be contained in recycled or reused metals or equipment. The preliminary results are compared with similar results reported by the International Atomic Energy Agency, by radionuclide grouping. (author)

  10. Optimisation of industrial wastes reuse as construction materials.

    Science.gov (United States)

    Collivignarelli, C; Sorlini, S

    2001-12-01

    This study concerns the reuse of two inorganic wastes, foundry residues and fly ashes from municipal solid waste incineration, as "recycled aggregate" in concrete production. This kind of reuse was optimised by waste treatment with the following steps: waste washing with water; waste stabilisation-solidification treatment with inorganic reagents; final grinding of the stabilised waste after curing for about 10-20 days. Both the treated wastes were reused in concrete production with different mix-designs. Concrete specimens were characterised by means of conventional physical-mechanical tests (compression, elasticity modulus, shrinkage) and different leaching tests. Experimental results showed that a good structural and environmental quality of "recycled concrete" is due both to a correct waste treatment and to a correct mix-design for concrete mixture.

  11. Radiological control criteria for materials considered for recycle and reuse

    International Nuclear Information System (INIS)

    Kennedy, W.E. Jr.; Hill, R.L.; Aaberg, R.L.; Wallo, A. III

    1994-11-01

    Pacific Northwest Laboratory (PNL) is conducting technical analyses to support the US Department of Energy (DOE), Office of Environmental Guidance, Air, Water, and Radiation Division (DOE/EH-232) in developing radiological control criteria for recycling or reuse of metals or equipment containing residual radioactive contamination from DOE operations. The criteria, framed as acceptable concentrations for release of materials for recycling or reuse, are risk-based and were developed through analysis of generic radiation exposure scenarios and pathways. The analysis includes evaluation of relevant radionuclides, potential mechanisms of exposure, and non-health-related impacts of residual radioactivity on electronics and film. The analysis considers 42 key radionuclides that DOE operations are known to generate and that may be contained in recycled or reused metals or equipment. Preliminary results are compared with similar results reported by the International Atomic Energy Agency, by radionuclide grouping

  12. Reduce, reuse, recycle for robust cluster-state generation

    International Nuclear Information System (INIS)

    Horsman, Clare; Brown, Katherine L.; Kendon, Vivien M.; Munro, William J.

    2011-01-01

    Efficient generation of cluster states is crucial for engineering large-scale measurement-based quantum computers. Hybrid matter-optical systems offer a robust, scalable path to this goal. Such systems have an ancilla which acts as a bus connecting the qubits. We show that by generating the cluster in smaller sections of interlocking bricks, reusing one ancilla per brick, the cluster can be produced with maximal efficiency, requiring fewer than half the operations compared with no bus reuse. By reducing the time required to prepare sections of the cluster, bus reuse more than doubles the size of the computational workspace that can be used before decoherence effects dominate. A row of buses in parallel provides fully scalable cluster-state generation requiring only 20 controlled-phase gates per bus use.

  13. Selecting a Sustainable Disinfection Technique for Wastewater Reuse Projects

    Directory of Open Access Journals (Sweden)

    Jorge Curiel-Esparza

    2014-09-01

    Full Text Available This paper presents an application of the Analytical Hierarchy Process (AHP by integrating a Delphi process for selecting the best sustainable disinfection technique for wastewater reuse projects. The proposed methodology provides project managers a tool to evaluate problems with multiple criteria and multiple alternatives which involve non-commeasurable decision criteria, with expert opinions playing a major role in the selection of these treatment technologies. Five disinfection techniques for wastewater reuse have been evaluated for each of the nine criteria weighted according to the opinions of consulted experts. Finally, the VIKOR method has been applied to determine a compromise solution, and to establish the stability of the results. Therefore, the expert system proposed to select the optimal disinfection alternative is a hybrid method combining the AHP with the Delphi method and the VIKOR technique, which is shown to be appropriate in realistic scenarios where multiple stakeholders are involved in the selection of a sustainable disinfection technique for wastewater reuse projects.

  14. Oilfield Produced Water Reuse and Reinjection with Membrane

    Directory of Open Access Journals (Sweden)

    Siagian Utjok W.R.

    2018-01-01

    Full Text Available Produced water has become a global environmental issue due to its huge volume and toxicity that may pose detrimental effects on receiving environment. Several approaches have been proposed to provide a strategy for produced water handling such as reinjection, reuse, or discharge. With various advantages, membrane technology has been increasingly used in produced water treatment replacing the conventional technologies. However, fouling is a major drawback of membrane processes in this application which needs to be controlled. This paper gives an overview and comparison of different produced water management. Special attention is given to produced water treatment for reuse purpose. Furthermore, the use of membrane processes in produced water reuse including performance, challenges, and future outlook are discussed.

  15. Impact of age on glomerular filtration estimates.

    Science.gov (United States)

    Douville, Pierre; Martel, Ariane R; Talbot, Jean; Desmeules, Simon; Langlois, Serge; Agharazii, Mohsen

    2009-01-01

    Glomerular filtration decreases progressively with age in adults. Predictive equation should have proper modelling to adequately account for normal senescence. Corrected 24-h creatinine clearances (CCLs) were measured in a cohort of 773 outpatients from 18 to 90 years old. Multiple linear regression was used to model the effect of age on glomerular filtration. Comparisons were made with the simplified MDRD and the MAYO equations. Impact of the derived equation was tested in a second cohort of 7551 patients with normal serum creatinine. While all equations show declining function with age, our results suggest that the GFR reduction is progressive after the age of 30 and continue to decline steadily after the age of 60. This leads to a convex curve in the multiple regression analysis that is best fitted by an equation including the quadratic term (age(2)). In contrast, the MDRD equation produces a faster decrease in early adulthood and a flatter curve after the age of 60 while the MAYO equation produces a more linear effect. MDRD results in the normal range are lower than those estimated by the MAYO equation. These equations, as applied on an independent cohort of 7551 normal outpatients from 18 to 102 years, produce different profile of evolution of GFR with age. Inclusion of a quadratic term for age in the formula estimating GFR results in better modelling of the natural decline of renal function associated with ageing. Furthermore, as GFR steadily declines after the age of 30, a single cut-off value of GFR normality for all ages leads to underdiagnosis of young adults and over diagnosis of elderly individuals. Guidelines should take into account the observed reduction of kidney function with age in normal population for optimal evaluation of eGFR.

  16. Performing Verification and Validation in Reuse-Based Software Engineering

    Science.gov (United States)

    Addy, Edward A.

    1999-01-01

    The implementation of reuse-based software engineering not only introduces new activities to the software development process, such as domain analysis and domain modeling, it also impacts other aspects of software engineering. Other areas of software engineering that are affected include Configuration Management, Testing, Quality Control, and Verification and Validation (V&V). Activities in each of these areas must be adapted to address the entire domain or product line rather than a specific application system. This paper discusses changes and enhancements to the V&V process, in order to adapt V&V to reuse-based software engineering.

  17. Wastewater Treatment and Reuse: Past, Present, and Future

    Directory of Open Access Journals (Sweden)

    Andreas N. Angelakis

    2015-09-01

    Full Text Available This paper provides an overview of the Special Issue on Wastewater Treatment and Reuse: Past, Present, and Future. The papers selected for publication include advanced wastewater treatment and monitoring technologies, such as membrane bioreactors, electrochemical systems; denitrifying biofilters, and disinfection technologies. The Issue also contains articles related to best management practices of biosolids, the influence of organic matter on pathogen inactivation and nutrient removal. Collectively, the Special Issue presents an evolution of technologies, from conventional through advanced, for reliable and sustainable wastewater treatment and reuse.

  18. Reusing Implicit Cooperation. A Novel Approach to Knowledge Management

    Directory of Open Access Journals (Sweden)

    Luigi Lancieri

    2008-07-01

    Full Text Available The study described in this paper deals with information reuse obtained by implicit co-operation, particularly by recycling the contents of a proxy cache (shared memory. The objective is to automatically feed a Web server with large multimedia objects implicitly centred on community fields of interests. We show that the strategy of reusing previously downloaded information provides interesting advantages at a low cost; in particular, to reduce Web access time, to improve information retrieval, and to reduce Internet bandwidth use. Moreover, we use the conceptual frameworks of forgetting and collective intelligence to develop a model on which the operation of implicit cooperation is based.

  19. A Case Study of Framework Design for Horizontal Reuse

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Røn, Henrik

    2000-01-01

    of similar decoupling techniques at the non-code level may give rise to technical mismatch problems between the framework and the client systems; (2) that such technical mismatch problems can be costly; and (3) that a reusable framework may beneficially provide a solution template when it cannot provide...... through the application of design patterns. We outline the reuse process and analyse and classify the problems encountered during the first-instance framework reuse. The major lessons learned are: (1) that, while design patterns are well-known for providing decoupling solutions at the code level, the lack...

  20. Improved semantic interoperability for content reuse through knowledge organization systems

    Directory of Open Access Journals (Sweden)

    José Antonio Moreiro González

    2012-04-01

    Full Text Available The Knowledge Organization Systems (KOS are resources designed to improve the knowledge interoperability, management and retrieval. As increases the web resources, it’s evidenced the lack of KOS, with the consequent impact in the resources interoperability. The KOSS are, by definition, complicated and costly tools, so much in his creation as in his management. The reuse of similar organizational structures is a necessary element in this context. They analyses experiences of reuse of The KOS and signals like the new standards are impinged on this appearance.

  1. Some aspects of applying nanostructured materials in air filtration, water filtration and electrical engineering

    Science.gov (United States)

    Kimmer, Dusan; Vincent, Ivo; Lovecka, Lenka; Kazda, Tomas; Giurg, Adam; Skorvan, Ondrej

    2017-05-01

    Nanostructures prepared from nanofibres and nanostructured composites prepared from nanofibres and fillers are gradually becoming increasingly demanded materials for applications in various industrial branches connected with catalysis, environment protection (air filtration, waste water treatment, sound absorption), in biological engineering, electronics (battery separators, electrode materials), etc. Selected applications of these materials prepared in the company SPUR a.s. are summed up in the following presentation.

  2. Mass coral bleaching causes biotic homogenization of reef fish assemblages.

    Science.gov (United States)

    Richardson, Laura E; Graham, Nicholas A J; Pratchett, Morgan S; Eurich, Jacob G; Hoey, Andrew S

    2018-04-06

    Global climate change is altering community composition across many ecosystems due to nonrandom species turnover, typically characterized by the loss of specialist species and increasing similarity of biological communities across spatial scales. As anthropogenic disturbances continue to alter species composition globally, there is a growing need to identify how species responses influence the establishment of distinct assemblages, such that management actions may be appropriately assigned. Here, we use trait-based analyses to compare temporal changes in five complementary indices of reef fish assemblage structure among six taxonomically distinct coral reef habitats exposed to a system-wide thermal stress event. Our results revealed increased taxonomic and functional similarity of previously distinct reef fish assemblages following mass coral bleaching, with changes characterized by subtle, but significant, shifts toward predominance of small-bodied, algal-farming habitat generalists. Furthermore, while the taxonomic or functional richness of fish assemblages did not change across all habitats, an increase in functional originality indicated an overall loss of functional redundancy. We also found that prebleaching coral composition better predicted changes in fish assemblage structure than the magnitude of coral loss. These results emphasize how measures of alpha diversity can mask important changes in the structure and functioning of ecosystems as assemblages reorganize. Our findings also highlight the role of coral species composition in structuring communities and influencing the diversity of responses of reef fishes to disturbance. As new coral species configurations emerge, their desirability will hinge upon the composition of associated species and their capacity to maintain key ecological processes in spite of ongoing disturbances. © 2018 John Wiley & Sons Ltd.

  3. In vitro study of the pulp chamber temperature rise during light-activated bleaching

    Directory of Open Access Journals (Sweden)

    Thaise Graciele Carrasco

    2008-10-01

    Full Text Available This study evaluated in vitro the pulp chamber temperature rise induced by the light-activated dental bleaching technique using different light sources. The root portions of 78 extracted sound human mandibular incisors were sectioned approximately 2 mm below the cementoenamel junction. The root cavities of the crowns were enlarged to facilitate the correct placing of the sensor into the pulp chamber. Half of specimens (n=39 was assigned to receive a 35% hydrogen peroxide gel on the buccal surface and the other halt (n=39 not to receive the bleaching agent. Three groups (n=13 were formed for each condition (bleach or no bleach according to the use of 3 light sources recommended for dental bleaching: a light-emitting diode (LEDlaser system, a LED unit and a conventional halogen light. The light sources were positioned perpendicular to the buccal surface at a distance of 5 mm and activated during 30 s. The differences between the initial and the highest temperature readings for each specimen were obtained, and, from the temperature changes, the means for each specimen and each group were calculated. The values of temperature rise were compared using Kruskal-Wallis test at 1% significance level. Temperature rise varied significantly depending on the light-curing unit, with statistically significant differences (p0.01. When the bleaching agent was applied, there were significant differences among groups (p<0.01: halogen light induced the highest temperature rise (1.41±0.64ºC, and LED-laser system the lowest (0.33±0.12ºC; however, there was no difference between LED-laser system and LED unit (0.44±0.11ºC. LED and LED-laser system did not differ significantly from each other regardless the temperature rise occurred with or without bleaching agent application. It may be concluded that during light-activated tooth bleaching, with or without the bleaching agent, halogen light promoted higher pulp chamber temperature rise than LED unit and LED

  4. Important clinical and laboratory correlates of glomerular filtration ...

    African Journals Online (AJOL)

    Background: Renal impairment is routinely assessed using the estimated glomerular filtration rate (eGFR) and it may be helpful to obtain certain clinical or laboratory markers, which show relationship with glomerular filtration rate (GFR) in sickle cell disease (SCD). Aim: To assess the relationship between important clinical ...

  5. Initial testing of electrospun nanofibre filters in water filtration ...

    African Journals Online (AJOL)

    2009-11-17

    Nov 17, 2009 ... techniques for the production of flat-sheet membranes and the application of these membranes in water filtration. ... be used for water filtration applications, but that further improvements are necessary before these membranes can be practically .... nanofibres so that the pore size increases and bacteria leak.

  6. A mathematical model for the leukocyte filtration process

    NARCIS (Netherlands)

    Bruil, A.; Bruil, Anton; Beugeling, T.; Beugeling, Tom; Feijen, Jan

    1995-01-01

    Leukocyte filters are applied clinically to remove leukocytes from blood. In order to optimize leukocyte filters, a mathematical model to describe the leukocyte filtration process was developed by modification of a general theoretical model for depth filtration. The model presented here can be used

  7. Noisy signal filtration using complex wavelet basis sets

    Science.gov (United States)

    Yaseen, A. S.; Pavlova, O. N.; Pavlov, A. N.

    2017-07-01

    Methods of noisy signal filtration using a discrete wavelet transform (DWT) with real basis sets of the Daubechies family are compared to methods employing a double-density dual-tree complex wavelet transform (DDCWT) with excess (nonorthonormalized) basis sets. Recommendations concerning the choice of filter parameters for minimization of the error of noisy signal filtration are formulated.

  8. Sand-Filtration System For Improving Water Quality For Rural ...

    African Journals Online (AJOL)

    Sand-Filtration System For Improving Water Quality For Rural Community Water Supply. AY Karikari, JA Ampofo. Abstract. The performance of a pilot sand filtration plant for a small town water supply was monitored over a seven month period to evaluate the physico-chemical and bacteriological quality of the filtered water ...

  9. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    In the last decade, pressure driven membrane filtration processes; reverse osmosis, nano, ultra and micro-filtration have undergone steady growth. Drivers for this growth include desalination to combat water scarcity and the removal of various material from water to comply with increasingly

  10. Effects of processing methods on sorghum wort filtration | Igyor ...

    African Journals Online (AJOL)

    Brewing parameters measured were filtration rate, specific gravity, viscosity, reducing sugars, hot water extract, soluble extract level, fermentable extract level, and fermentability level. Results revealed that though the sorghum worts had faster filtration rate than barley in infusion at 65°C, other brewing parameters were all ...

  11. Filter aids influence on pressure drop across a filtration system

    Science.gov (United States)

    Hajar, S.; Rashid, M.; Nurnadia, A.; Ammar, M. R.; Hasfalina, C. M.

    2017-06-01

    Filter aids is commonly used to reduce pressure drop across air filtration system as it helps to increase the efficiency of filtration of accumulated filter cake. Filtration velocity is one of the main parameters that affect the performance of filter aids material. In this study, a formulated filter aids consisting of PreKot™ and activated carbon mixture (designated as PrekotAC) was tested on PTFE filter media under various filtration velocities of 5, 6, and 8 m/min at a constant material loading of 0.2 mg/mm2. Results showed that pressure drop is highly influenced by filtration velocity where higher filtration velocity leads to a higher pressure drop across the filter cake. It was found that PrekotAC performed better in terms of reducing the pressure drop across the filter cake even at the highest filtration velocity. The diversity in different particle size distribution of non-uniform particle size in the formulated PrekotAC mixture presents a higher permeability causes a lower pressure drop across the accumulated filter cake. The finding suggests that PrekotAC is a promising filter aids material that helps reducing the pressure drop across fabric filtration system.

  12. Life Support Filtration System Trade Study for Deep Space Missions

    Science.gov (United States)

    Agui, Juan H.; Perry, Jay L.

    2017-01-01

    The National Aeronautics and Space Administrations (NASA) technical developments for highly reliable life support systems aim to maximize the viability of long duration deep space missions. Among the life support system functions, airborne particulate matter filtration is a significant driver of launch mass because of the large geometry required to provide adequate filtration performance and because of the number of replacement filters needed to a sustain a mission. A trade analysis incorporating various launch, operational and maintenance parameters was conducted to investigate the trade-offs between the various particulate matter filtration configurations. In addition to typical launch parameters such as mass, volume and power, the amount of crew time dedicated to system maintenance becomes an increasingly crucial factor for long duration missions. The trade analysis evaluated these parameters for conventional particulate matter filtration technologies and a new multi-stage particulate matter filtration system under development by NASAs Glenn Research Center. The multi-stage filtration system features modular components that allow for physical configuration flexibility. Specifically, the filtration system components can be configured in distributed, centralized, and hybrid physical layouts that can result in considerable mass savings compared to conventional particulate matter filtration technologies. The trade analysis results are presented and implications for future transit and surface missions are discussed.

  13. Purification of contaminated water by filtration through porous glass

    Science.gov (United States)

    Wydeven, T.; Leban, M. I.

    1972-01-01

    Method for purifying water that is contaminated with mineral salts and soluble organic compounds is described. Method consists of high pressure filtration of contaminated water through stabilized porous glass membranes. Procedure for conducting filtration is described. Types of materials by percentage amounts removed from the water are identified.

  14. 40 CFR 141.71 - Criteria for avoiding filtration.

    Science.gov (United States)

    2010-07-01

    ... Criteria for avoiding filtration. A public water system that uses a surface water source must meet all of...)(C)(iii), that filtration is required. A public water system that uses a ground water source under... it can control all human activities which may have an adverse impact on the microbiological quality...

  15. Harvesting microalgal biomass using crossflow membrane filtration: critical flux, filtration performance, and fouling characterization.

    Science.gov (United States)

    Elcik, Harun; Cakmakci, Mehmet

    2017-06-01

    The purpose of this study was to investigate the efficient harvesting of microalgal biomass through crossflow membrane filtration. The microalgal biomass harvesting experiments were performed using one microfiltration membrane (pore size: 0.2 µm, made from polyvinylidene fluoride) and three ultrafiltration membranes (molecular weight cut-off: 150, 50, and 30 kDa, made from polyethersulfone, hydrophilic polyethersulfone, and regenerated cellulose, respectively). Initially, to minimize membrane fouling caused by microalgal cells, experiments with the objective of determining the critical flux were performed. Based on the critical flux calculations, the best performing membrane was confirmed to be the UH050 membrane, produced from hydrophilic polyethersulfone material. Furthermore, we also evaluated the effect of transmembrane pressure (TMP) and crossflow velocity (CFV) on filtration flux. It was observed that membrane fouling was affected not only by the membrane characteristics, but also by the TMP and CFV. In all the membranes, it was observed that increasing CFV was associated with increasing filtration flux, independent of the TMP.

  16. Variables and potential models for the bleaching of luminescence signals in fluvial environments

    Science.gov (United States)

    Gray, Harrison J.; Mahan, Shannon

    2015-01-01

    Luminescence dating of fluvial sediments rests on the assumption that sufficient sunlight is available to remove a previously obtained signal in a process deemed bleaching. However, luminescence signals obtained from sediment in the active channels of rivers often contain residual signals. This paper explores and attempts to build theoretical models for the bleaching of luminescence signals in fluvial settings. We present two models, one for sediment transported in an episodic manner, such as flood-driven washes in arid environments, and one for sediment transported in a continuous manner, such as in large continental scale rivers. The episodic flow model assumes that the majority of sediment is bleached while exposed to sunlight at the near surface between flood events and predicts a power-law decay in luminescence signal with downstream transport distance. The continuous flow model is developed by combining the Beer–Lambert law for the attenuation of light through a water column with a general-order kinetics equation to produce an equation with the form of a double negative exponential. The inflection point of this equation is compared with the sediment concentration from a Rouse profile to derive a non-dimensional number capable of assessing the likely extent of bleaching for a given set of luminescence and fluvial parameters. Although these models are theoretically based and not yet necessarily applicable to real-world fluvial systems, we introduce these ideas to stimulate discussion and encourage the development of comprehensive bleaching models with predictive power.

  17. THE EFFECTS OF HOME BLEACHING ON THE HARDNESS OF AMALGAM FILLING

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    Andi Soufyan

    2015-06-01

    Full Text Available Dental bleaching has been considered as a feasible approach for dental esthetic, and many dental bleaching products can be seen in the market. Therefore, the side effect of such dental product should be studied. This study was aimed to determine the effect of carbamide peroxide-containing home bleaching agent on the hardness of dental amalgam surface structure. Forty amalgam filling specimens were divided into 4 groups, which consist of 3 treatment groups and 1 controu group. Each group was exposed to the bleaching agent daily for 2, 4 and 8 hours within 7 days. The Vickers Microhardness Tester, with loads 98.07 mN for 20 seconds, was used to measure the hardness of amalgam surface. It was revealed that, there was a significant difference between the treatment and the control group on 8 hours period. It was concluded that there was a decrease in hardness of dental amalgam surface after having a contact with carbamide peroxide bleaching agent.

  18. Multiple opportunistic pathogens can cause a bleaching disease in the red seaweed Delisea pulchra.

    Science.gov (United States)

    Kumar, Vipra; Zozaya-Valdes, Enrique; Kjelleberg, Staffan; Thomas, Torsten; Egan, Suhelen

    2016-11-01

    While macroalgae (or seaweeds) are increasingly recognized to suffer from disease, in most cases the causative agents are unknown. The model macroalga Delisea pulchra is susceptible to a bleaching disease and previous work has identified two epiphytic bacteria, belonging to the Roseobacter clade, that cause bleaching under laboratory conditions. However, recent environmental surveys have shown that these in vitro pathogens are not abundant in naturally bleached D. pulchra, suggesting the presence of other pathogens capable of causing this algal disease. To test this hypothesis, we cultured bacteria that were abundant on bleached tissue across multiple disease events and assessed their ability to cause bleaching disease. We identified the new pathogens Alteromonas sp. BL110, Aquimarina sp. AD1 and BL5 and Agarivorans sp BL7 that are phylogenetically diverse, distinct from the previous two pathogens and can also be found in low abundance in healthy individuals. Moreover, we found that bacterial communities of diseased individuals that were infected with these pathogens were less diverse and more divergent from each other than those of healthy algae. This study demonstrates that multiple and opportunistic pathogens can cause the same disease outcome for D. pulchra and we postulate that such pathogens are more common in marine systems than previously anticipated. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Bleach treatment of sputum samples aids pulmonary tuberculosis screening among HIV-infected patients in Laos.

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    Thammavong, C; Paboriboune, P; Bouchard, B; Harimanana, A; Babin, F-X; Phimmasone, P; Berland, J-L; Buisson, Y

    2011-10-01

    Laos has a high prevalence of tuberculosis (TB) and a slowly increasing prevalence of human immunodeficiency virus/acquired immunedeficiency syndrome (HIV/AIDS). Sputum smear microscopy is the only method currently available for routine screening of pulmonary TB, although it only detects one in three cases among persons living with HIV (PLWH). Bleach treatment of sputum samples (bleach method) has been shown to significantly improve the sensitivity of the test; however, its effectiveness in PLWH remains to be determined in Laos. To determine the performance of the bleach method as a diagnostic tool for pulmonary TB in PLWH and to assess its cost-effectiveness in Laos. Of 174 sputum samples collected from 92 patients, 29 were culture-positive for Mycobacterium tuberculosis in 17 patients. The sensitivity of the direct method and the bleach method was respectively 59% and 93%, and specificity was 100% for both methods. The incremental cost-effectiveness ratio for screening an additional case was US$17.40. The bleach method is simple, cheap, easy to perform and cost-effective in PLWH. Its implementation in laboratories involved in routine screening of pulmonary TB among PLWH would allow practitioners to start the treatment of this life-threatening co-infection earlier.

  20. Effect of Home Bleaching on the Translucency of CAD/CAM Systems.

    Science.gov (United States)

    Karci, Muhammet; Demir, Necla

    2017-11-10

    To evaluate the effect of a home bleaching agent (Opalescence PF) on the translucency of CAD/CAM ceramic systems. The 28 sintered ceramic specimens (IPS Empress CAD and IPS e.max CAD; 15 mm long, 10 mm wide, 1 mm thick) were divided into two subgroups as control and bleaching groups (n = 7). Carbamide peroxide (CP), 16%, home bleaching agent was applied onto the surface of each specimen for 6 hours per day for 7 days. A spectrophotometer (VITA Easyshade Advance) was used to measure the CIE L * a * b * coordinates and the reflectance value (Y) of the specimens on white and black backgrounds. The translucency parameter (TP), contrast ratio (CR), and opalescence parameter (OP) of the specimens were calculated. The data were statistically analyzed using Kolmogorov-Smirnov, one-way ANOVA, Tukey's test, and Pearson's correlation. Statistically significant differences in the TP values after 16% CP bleaching treatment were observed (p ˂ 0.05); however, no significant differences were found in the OP and CR values after the surface treatment (p ˃ 0.05). According to our study, patients who have all-ceramic restorations in their mouths should be careful when using home bleaching agents, because whitening agents can affect the translucency of all-ceramic restorations such as e.max CAD and Empress CAD. © 2017 by the American College of Prosthodontists.