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Sample records for multi-purpose disinfecting solution

  1. Disinfecting action of a new multi-purpose disinfection solution for contact lenses.

    PubMed

    Rosenthal, R A; Bell, W M; Abshire, R

    1999-01-01

    The disinfection activity of a new multipurpose disinfection solution (OPTI-FREE Express with ALDOX) was compared to several other contact lens disinfecting solutions. The new solution is preserved with polyquaternium-1 and myristamidopropyl dimethylamine. The other solutions included 3% hydrogen peroxide systems and multipurpose solutions (MPS) preserved with polyhexamethylene biguanide. The products were tested for antimicrobial activity against Staphylococcus spp., Pseudomonas aeruginosa, Serratia marcescens, Candida albicans, Fusarium solani, and Aspergillus fumigatus. OPTI-FREE Express provided a broader range of antimicrobial activity than the MPS. It provided activity similar to that demonstrated by 3% hydrogen peroxide systems, but unlike the hydrogen peroxide system tested, it also prevented re growth of the organisms during extended storage. PMID:16303414

  2. A multicenter investigation of OPTI-FREE® RepleniSH® multi-purpose disinfecting solution impact on soft contact lens patient comfort

    PubMed Central

    Corbin, Glenn S; Bennett, Linda; Espejo, Louis; Carducci, Suzanne; Sacco, Andrew; Hannigan, Robert; Schatz, Stuart

    2010-01-01

    Objective: Demonstrate that successful soft contact lens wearers using competitive multipurpose solutions report improvement in comfort with OPTI-FREE® RepleniSH® Multi-Purpose Disinfecting Solution (MPDS). Methods: This 30-day, multicentered, open-label study enrolled 109 eligible soft contact lens wearers using COMPLETE® Multi-Purpose Solution (MPS) Easy Rub® or ReNu MultiPlus® MPS. The test solution (OPTI-FREE® RepleniSH® MPDS) was dispensed for use in place of habitual care solutions. Subjects assessed their experience with their habitual solution (baseline) and the test solution (Day 30) using Likert-style questions. Contact lens acuity and biomicroscopy findings were recorded at each visit. Results: The test solution was associated with a statistically significant improvement in instillation comfort (P = 0.02), end of day comfort (P < 0.0001), clear vision (P < 0.0001) and overall satisfaction (P < 0.001). Subjects reported the test solution enhanced their overall lens-wearing experience more effectively than their previous solution (P < 0.0001) and that they would continue test solution use after the study (P < 0.0001). Conclusions: The test solution was effective at improving comfort and overall contact lens experience compared to COMPLETE® MPS Easy Rub® or ReNu MultiPlus® MPS in successful contact lens wearers. These results indicate that changing contact lens care solutions, even in successful lens wearers, may improve comfort and overall lens-wearing experience. PMID:20169049

  3. Multi-Purpose Tests: A Solution to Test Proliferation.

    ERIC Educational Resources Information Center

    Holmes, Susan E.

    This research, conducted for California State Department of Education, is one component of a feasibility study focusing on ways to make the testing process more efficient by application of multi-purpose tests (MPT). MPT are designed, administered and scored to serve more than one purpose and to consolidate and unify testing programs as a partial…

  4. Use of buffered hypochlorite solution for disinfecting fibrescopes.

    PubMed Central

    Coates, D; Death, J E

    1982-01-01

    The possible use of sodium hypochlorite solution buffered to pH 7.6 and containing 100 ppm available chlorine (avCl) for disinfecting fibrescopes was investigated. A flexible fibrescope experimentally contaminated with Pseudomonas putida, Mycobacterium fortuitum, or Bacillus subtilis spores was effectively disinfected within 10 m in repeatedly and without any observable adverse effect on the instrument. The corrosive nature of buffered hypochlorite was investigated by immersing various fibrescope components and metal wires in solutions of different strength for long periods and examining them for damage. Stainless steel, platinum, glass, Teflon, polythene and epoxy resin were apparently unaffected whereas polyurethane, rubber and other metals tested were damaged to different extents. Buffered hypochlorite solutions may have many applications pertaining to the disinfection of items which are either thermolabile or require rapid effective disinfection. PMID:6802880

  5. Evaluating the potential of multi-purpose nature based solutions in peri-urban landscapes - a preliminary assessment

    NASA Astrophysics Data System (ADS)

    Geris, Josie; Wilkinson, Mark; Stutter, Marc; Guenther, Daniel; Soulsby, Chris

    2016-04-01

    Many communities across the world face the increasing challenge of balancing water quantity and quality protection and improvement with accommodating new growth and urban development. Urbanisation is typically associated with detrimental changes in water quality, sediment delivery, and effects on water storage and flow pathways (e.g. increases in flooding). Current mitigation solutions are typically based on isolated design strategies used at specific small scale sites and for storm water only. More holistic catchment scale approaches are urgently required to effectively manage the amount of water flows and protect the raw water quality in peri-urban landscapes. This project aims to provide a better understanding of the connectivity between natural and managed flow pathways, storage, and biogeochemical processes in the peri-urban landscape to eventually aid a more integrated water quantity and quality control design. For an actively urbanising catchment in NE Scotland we seek to understand the spatio-temporal character of the natural flow pathways and associated water quality, and how these may be used to support the design of nature based solutions during urbanisation. We present preliminary findings from a dense and multiscale monitoring network that includes hydrometric, tracer (stable water isotopes) and water quality (turbidity (sediment), nitrate, phosphate) data during a range of contrasting hydroclimatological conditions and at different stages of the development of urban infrastructure. These demonstrate a highly variable nature, both temporally and spatially, with water quality dynamics out of sync with storm responses and depending on management practices. This highlights potential difficulties for managing water quantity and quality simultaneously at the catchment scale, and suggests that a treatment train approach may be required. Well-designed nature based solutions that tackle both water quantity and quality issues will require adaptability and a

  6. Belford proactive flood solutions: scientific evidence to influence local and national policy by multi-purpose runoff management

    NASA Astrophysics Data System (ADS)

    Wilkinson, M.; Quinn, P. F.; Jonczyk, J.

    2010-12-01

    The increased risk from flooding continues to be of concern to governments all around the world and flood protection is becoming more of a challenge. In the UK, climate change projections indicate more extremes within the weather systems. In addition, there is an increased demand for using land in urban areas beside channels. These developments both put pressure on our flood defences and there is a need for new solutions to managing flood risk. There is currently support within the England and Wales Environment Agency for sustainable flood management solutions such as storage ponds, wetlands, beaver dams and willow riparian features (referred to here as Runoff Attenuation Features, or RAFs). However the effectiveness of RAFs are not known at the catchment scale since they have only really been trailed at the plot scale. These types of mitigation measure can offer benefits to water quality and create ecological habitats. The village of Belford, situated in the Belford Burn catchment (6km2), northern England, has suffered from numerous flood events. In addition, the catchment suffers from water quality issues within the channel and high sediment loads are having an impact on the ecology of the nearby estuary. There was a desire by the Local Environment Agency Flood Levy team to deliver an alternative catchment-based solution to the problem. With funding from the Northumbria Regional Flood Defence Committee, the Environment Agency North East Local Levy team and Newcastle University have created a partnership to address the flood problem trailing soft engineered RAF’s at the catchment scale. The partnership project, “Belford proactive flood solutions” is testing novel techniques in reducing flood risk in small sub-catchments for the Environment Agency. The project provides the information needed to understand whether the multi-functional mitigation measures are working at the sub-catchment scale. Data suggest that the mitigation measures present have delayed the

  7. Amoebicidal activity of a preserved contact lens multipurpose disinfecting solution compared to a disinfection/neutralisation peroxide system.

    PubMed

    Buck, S L; Rosenthal, R A; Abshire, R L

    1998-01-01

    The amoebicidal activity of a contact lens multipurpose disinfecting solution (MPDS) containing polyquaternium-1 and myristamidopropyl dimethylamine was compared to a disinfection/neutralisation peroxide system against Acanthamoeba castellanii and Acanthamoeba polyphaga trophozoites and cysts. A quantitative microtitre method was used to evaluate the solutions. The MPDS showed similar amoebicidal activity to the disinfection/neutralisation peroxide system against the trophozoites of both species and equal or more rapid activity against the cysts of both species. PMID:16303382

  8. 9 CFR 96.14 - Uncertified casings; disinfection with saturated brine solution.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... for importation into the United States upon disinfection, may either be disinfected with hydrochloric acid as at present or if preferred may be submerged in a saturated brine solution at a temperature...

  9. 9 CFR 96.14 - Uncertified casings; disinfection with saturated brine solution.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... for importation into the United States upon disinfection, may either be disinfected with hydrochloric acid as at present or if preferred may be submerged in a saturated brine solution at a temperature...

  10. 9 CFR 96.14 - Uncertified casings; disinfection with saturated brine solution.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... for importation into the United States upon disinfection, may either be disinfected with hydrochloric acid as at present or if preferred may be submerged in a saturated brine solution at a temperature...

  11. 9 CFR 96.14 - Uncertified casings; disinfection with saturated brine solution.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... for importation into the United States upon disinfection, may either be disinfected with hydrochloric acid as at present or if preferred may be submerged in a saturated brine solution at a temperature...

  12. Susceptibility of Acanthamoeba castellanii to contact lens disinfecting solutions.

    PubMed Central

    Zanetti, S; Fiori, P L; Pinna, A; Usai, S; Carta, F; Fadda, G

    1995-01-01

    A corneal isolate of Acanthamoeba castellanii was exposed to commercial contact lens disinfecting solutions containing hydrogen peroxide, benzalkonium chloride, polyaminopropyl biguanide, polyquaternium 1, and chlorhexidine-thimerosal. The minimum trophozoite amebicidal concentration and exposure times required to kill trophozoites and cysts were determined. Solutions containing hydrogen peroxide or chlorhexidine-thimerosal were active against both trophozoites and cysts. The benzalkonium chloride-based solution was effective only against trophozoites. Solutions containing polyaminopropyl biguanide or polyquaternium 1 were completely ineffective. The need for adequate exposure times must be stressed. PMID:7492111

  13. D-value determinations are an inappropriate measure of disinfecting activity of common contact lens disinfecting solutions.

    PubMed Central

    Sutton, S V; Franco, R J; Porter, D A; Mowrey-McKee, M F; Busschaert, S C; Hamberger, J F; Proud, D W

    1991-01-01

    Determination of a D value for specific test organisms is a component of the efficacy evaluation of new contact lens disinfecting solutions. This parameter is commonly defined as the time required for the number of surviving microorganisms to decrease 1 logarithmic unit. The assumption made in establishing a D value is that the rate of kill exhibits first-order kinetics under the specified conditions. Such exponential kill rates are seen with thermal contact lens disinfection system. A comparison of the death rate kinetics for a variety of chemical contact lens disinfecting solutions was undertaken to ascertain the suitability of D-value determination for these chemical disinfectants. The active agents of these different solutions included hydrogen peroxide, thimerosal, chlorhexidine, tris(2-hydroxyethyl)tallow ammonium chloride, thimerosal, polyaminopropyl biguanide, and polyquaternium-1. The solutions were challenged with 10(6) CFU of either Pseudomonas aeruginosa, Serratia marcescens, or Staphylococcus hominis per ml, and survival rate was determined. This study clearly demonstrates the nonlinear nature of the inactivation curves for most contact lens chemical disinfecting solutions for the challenge organisms. D-value determination is, therefore, an inappropriate method of reporting the biocidal activity of these solutions. PMID:1892391

  14. Disinfection.

    ERIC Educational Resources Information Center

    Gould, J. P.; Haas, C. N.

    1978-01-01

    Presents a literature review of wastewater disinfection for 1978. This review covers areas such as: (1) mechanisms of inactivation of negative microorganisms by chlorine and ozone; and (2) the effects of various treatment on over-all water quality. A list of 61 references is also presented. (HM)

  15. DISINFECTION

    EPA Science Inventory

    The primary goal of the disinfection process in drinking water treatment is the inactivation of microbial pathogens. These pathogens comprise a diverse group of organisms which serve as the etiological agents of waterborne disease. Included in this group are bacterial, viral and ...

  16. Multi-purpose satellite bus

    NASA Technical Reports Server (NTRS)

    Sakoda, Daniel; Agrawal, Brij N.

    1991-01-01

    The Multi-Purpose Satellite bus (MPS) can be used for a number of payloads which may require different orbits, pointing accuracy, and electrical power consumption. Specifically, it was designed to accommodate the Advanced Very High Resolution Radiometer and an EHF communication payload, both of which have a three-year life. The estimated beginning-of-life weight of the MPS bus is 150 kg. It can be launched by either the Pegasus ALV or the Taurus SSLV. Configuration requirements for the different missions are discussed.

  17. Disinfection of preexisting contamination of bacillus cereus on stainless steel when using glycoconjugate solution

    SciTech Connect

    Pavan, Casey; Tarasenko, Olga

    2011-06-10

    Stainless steel is ubiquitous in our modern world, however it can become contaminated. This can endanger our health. The aim of our study is to disinfect stainless steel using Bacillus cereus as a model organism. Bacillus cereus is a microbe that is ubiquitous in nature, specifically soil. B. cereus is known to cause illness in humans. To prevent this, we propose to use a glycoconjugate solution (GS) for disinfection of stainless steel after it is contamination by B. cereus spores. In this study, two GS (9, 10) were tested for disinfection effectiveness on B. cereus spores on the surface of stainless steel foil (AISI-Series 200/300/400, THERMA-FOIL, Dayville, CT 0241). The disinfection rate of each GS was assessed by exposing the steel surface to B. cereus spores first and allowing them to settle for 24 hours. GS was used to treat the contaminated surface. The steel is washed and the resulting solution is plated on tryptic soy agar (TSA) plates. The GS with the fewest colony forming unit (CFU) formed on TSA is determined to be the most efficient during disinfection. Results show that both GS demonstrate a strong ability to disinfect B. cereus spores. Between the two, GS 9 shows the highest disinfection efficacy by killing approximately 99.5% of spores. This is a drastic improvement over the 0-20% disinfection of the control. Based on this we find that studied GS do have the capacity to act as a disinfectant on stainless steel.

  18. Disinfection of Preexisting Contamination of BACILLUS CEREUS on Stainless Steel when Using Glycoconjugate Solution

    NASA Astrophysics Data System (ADS)

    Pavan, Casey; Tarasenko, Olga

    2011-06-01

    Stainless steel is ubiquitous in our modern world, however it can become contaminated. This can endanger our health. The aim of our study is to disinfect stainless steel using Bacillus cereus as a model organism. Bacillus cereus is a microbe that is ubiquitous in nature, specifically soil. B. cereus is known to cause illness in humans. To prevent this, we propose to use a glycoconjugate solution (GS) for disinfection of stainless steel after it is contamination by B. cereus spores. In this study, two GS (9, 10) were tested for disinfection effectiveness on B. cereus spores on the surface of stainless steel foil (AISI-Series 200/300/400, THERMA-FOIL, Dayville, CT 0241). The disinfection rate of each GS was assessed by exposing the steel surface to B. cereus spores first and allowing them to settle for 24 hours. GS was used to treat the contaminated surface. The steel is washed and the resulting solution is plated on tryptic soy agar (TSA) plates. The GS with the fewest colony forming unit (CFU) formed on TSA is determined to be the most efficient during disinfection. Results show that both GS demonstrate a strong ability to disinfect B. cereus spores. Between the two, GS 9 shows the highest disinfection efficacy by killing approximately 99.5% of spores. This is a drastic improvement over the 0-20% disinfection of the control. Based on this we find that studied GS do have the capacity to act as a disinfectant on stainless steel.

  19. Comparative study of antibacterial and antifungal effects of rigid gas permeable contact lens disinfecting solutions.

    PubMed

    Kuzman, Tomislav; Kutija, Marija Barisić; Kordić, Rajko; Popović-Sui, Smiljka; Jandroković, Sonja; Skegro, Ivan; Pokupec, Rajko

    2013-04-01

    The aim of this study was to compare antimicrobial efficacy of rigid contact lens disinfecting solutions. We tested five commercially available solutions: Unique pH (Alcon Laboratories), Boston Advance (Polymer Technology Corp.), Nitilens Conditioner GP (Avizor), Total Care (AMO), Boston Simplus (Bausch&Lomb). Their efficacy to disinfect saline solution experimentally contaminated with American Type Culture Collection (ATCC): Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Candida albicans (ATCC 90028) and Staphylococcus epidermidis (isolated from our laboratory) was tested. All tested solutions reduced concentrations of bacteria and fungi below 1000 CFU/mL (Colony forming unit; reduction by 3 log and 1 log, respectively) after the 8 hours period. Overall, all contact lens care solutions showed good disinfecting activity against tested bacteria and fungi, with more variation in their antifungal than in antibacterial efficacy. Results of our study might be valuable when selecting appropriate solutions for non-compliant contact lens wearers. PMID:23837231

  20. Configurable Multi-Purpose Processor

    NASA Technical Reports Server (NTRS)

    Valencia, J. Emilio; Forney, Chirstopher; Morrison, Robert; Birr, Richard

    2010-01-01

    Advancements in technology have allowed the miniaturization of systems used in aerospace vehicles. This technology is driven by the need for next-generation systems that provide reliable, responsive, and cost-effective range operations while providing increased capabilities such as simultaneous mission support, increased launch trajectories, improved launch, and landing opportunities, etc. Leveraging the newest technologies, the command and telemetry processor (CTP) concept provides for a compact, flexible, and integrated solution for flight command and telemetry systems and range systems. The CTP is a relatively small circuit board that serves as a processing platform for high dynamic, high vibration environments. The CTP can be reconfigured and reprogrammed, allowing it to be adapted for many different applications. The design is centered around a configurable field-programmable gate array (FPGA) device that contains numerous logic cells that can be used to implement traditional integrated circuits. The FPGA contains two PowerPC processors running the Vx-Works real-time operating system and are used to execute software programs specific to each application. The CTP was designed and developed specifically to provide telemetry functions; namely, the command processing, telemetry processing, and GPS metric tracking of a flight vehicle. However, it can be used as a general-purpose processor board to perform numerous functions implemented in either hardware or software using the FPGA s processors and/or logic cells. Functionally, the CTP was designed for range safety applications where it would ultimately become part of a vehicle s flight termination system. Consequently, the major functions of the CTP are to perform the forward link command processing, GPS metric tracking, return link telemetry data processing, error detection and correction, data encryption/ decryption, and initiate flight termination action commands. Also, the CTP had to be designed to survive and

  1. Adaptation and growth of Serratia marcescens in contact lens disinfectant solutions containing chlorhexidine gluconate.

    PubMed Central

    Gandhi, P A; Sawant, A D; Wilson, L A; Ahearn, D G

    1993-01-01

    Serratia marcescens (11 of 12 strains) demonstrated an ability to grow in certain chlorhexidine-based disinfecting solutions recommended for rigid gas-permeable contact lenses. For a representative strain, cells that were grown in nutrient-rich medium, washed, and inoculated into disinfecting solution went into a nonrecoverable phase within 24 h. However, after 4 days, cells that had the ability to grow in the disinfectant (doubling time, g = 5.7 h) emerged. Solutions supporting growth of S. marcescens were filter sterilized. These solutions, even after removal of the cells, showed bactericidal activity against Pseudomonas aeruginosa and a biphasic survival curve when rechallenged with S. marcescens. Adaptation to chlorhexidine by S. marcescens was not observed in solutions formulated with borate ions. For chlorhexidine-adapted cells, the MIC of chlorhexidine in saline was eightfold higher than that for unadapted cells. Cells adapted to chlorhexidine showed alterations in the proteins of the outer membrane and increased adherence to polyethylene. Cells adapted to chlorhexidine persisted or grew in several other contact lens solutions with different antimicrobial agents, including benzalkonium chloride. Images PMID:8439148

  2. Phytochemical profiling as a solution to palliate disinfectant limitations.

    PubMed

    Malheiro, J; Gomes, I; Borges, A; Bastos, M M S M; Maillard, J-Y; Borges, F; Simões, M

    2016-10-01

    The indiscriminate use of biocides for general disinfection has contributed to the increased incidence of antimicrobial tolerant microorganisms. This study aims to assess the potential of seven phytochemicals (tyrosol, caffeic acid, ferulic acid, cinnamaldehyde, coumaric acid, cinnamic acid and eugenol) in the control of planktonic and sessile cells of Staphylococcus aureus and Escherichia coli. Cinnamaldehyde and eugenol showed antimicrobial properties, minimum inhibitory concentrations of 3-5 and 5-12 mM and minimum bactericidal concentrations of 10-12 and 10-14 mM against S. aureus and E. coli, respectively. Cinnamic acid was able to completely control adhered bacteria with effects comparable to peracetic acid and sodium hypochlorite and it was more effective than hydrogen peroxide (all at 10 mM). This phytochemical caused significant changes in bacterial membrane hydrophilicity. The observed effectiveness of phytochemicals makes them interesting alternatives and/or complementary products to commonly used biocidal products. Cinnamic acid is of particular interest for the control of sessile cells. PMID:27552663

  3. The use of electrolyzed solutions for the cleaning and disinfecting of dialyzers.

    PubMed

    Tanaka, N; Tanaka, N; Fujisawa, T; Daimon, T; Fujiwara, K; Yamamoto, M; Abe, T

    2000-12-01

    Recently, the use of electrolyzed solutions has attracted considerable interest in Japan. This study investigates the efficiency of electrolyzed solutions as disinfecting agents (DA) in the reuse of dialyzers and compares their efficiency to that of other disinfectants currently in use. The following 3 methods were employed. First, the rinsing time and rebound release of reused dialyzers were measured and compared after electrolyzed solutions, electrolyzed strong acid aqueous solution (ESAAS) and electrolyzed strong basic aqueous solution (ESBAS), made from reverse osmosis (RO) water (ESAAS, ESBAS; Generating apparatuses: Super Oxseed alpha 1000, Amano Corporation, Yokohama, Japan), 2% Dialox-cj (Teijin Gambro Medical, Tokyo, Japan), and 3.8% formalin were used as DAs. This involved performing dialysis with 2 types of dialyzers: a cellulose acetate membrane (CAM) dialyzer and a polysulfone membrane (PSM) dialyzer. The dialyzers were cleaned and disinfected using the different DA and left for 48 h. Next, after performing dialysis the dialyzer membranes were cleaned with a saline solution (0.9% NaCl) and RO water and then cleaned with the various DA. These membranes were observed using a scanning electron microscope (SEM) to check for the presence of physical and biological contaminants. Finally, in vitro tests were performed to determine the level of dialyzer clearance when PSM dialyzers were reused after having been cleaned and disinfected with the electrolyzed solutions. The rinsing time results for both the CAM and PSM dialyzers showed the electrolyzed solutions (ESBAS and ESAAS) as being undetectable within 10 min. With regard to the rebound release, for both the CAM and PSM dialyzers, the electrolyzed solutions were undetectable at all checking times between 30 and 240 min. Observation by SEM showed that cleaning with both ESAAS and ESBAS left the fewest contaminants, and cleaning with 2% Dialox-cj left the highest level of contaminants in the CAM dialyzers

  4. The cleaning and disinfecting of hemodialysis equipment using electrolyzed strong acid aqueous solution.

    PubMed

    Tanaka, N; Fujisawa, T; Daimon, T; Fujiwara, K; Yamamoto, M; Abe, T

    1999-04-01

    In general, sodium hypochlorite, formalin, and Dialox (Teijin Gambro Medical, Ltd., Tokyo, Japan [main ingredients: H2O2, CH3CHOOOH, CH3COOH, H2O]) are used to clean and disinfect hemodialysis pipelines. In this study, the suitability of electrolyzed strong acid aqueous solution (ESAAS), which has attracted considerable interest in Japan because of its strong disinfecting properties, was examined. The crossover method was used to investigate the effectiveness of ESAAS in disinfecting the dialysis pipelines in comparison to that of sodium hypochlorite (200 ppm) used alternately with 1% acetic acid. The number of bacteria and the concentration of endotoxin (Et) were measured over an approximately 3 year period, starting in September 1994. Until then, 200 ppm sodium hypochlorite had been used alternately with 1% acetic acid, and the contamination of the pipeline had been marked. However, after switching to the ESAAS disinfection method, the dialysis pipelines very rapidly became cleaner. Therefore, the decision to develop an automated ESAAS cleaning system for long-term use was made. During the development period, the original disinfectants (200 ppm sodium hypochlorite used alternately with 1% acetic acid) were used as a stopgap. After confirmation of its performance and safety, the automated ESAAS cleaning system was introduced. To find out whether the decrease in bacteria secondarily caused a decrease in the Et concentration or whether the ESAAS directly inactivated the Et, an in vitro experiment was carried out. Highly concentrated Et, which had been left in the reverse osmosis (RO) drainage pipeline, was used as a sample to investigate the effects of ESAAS on Et at various concentrations and temperatures and on the recovery test. The results showed that ESAAS directly inactivated Et. This paper reports the results of the crossover test. The results of parallel tests carried out over an approximately 4 year period have already been reported. No significant problems

  5. New formaldehyde base disinfectants.

    NASA Technical Reports Server (NTRS)

    Trujillo, R.; Lindell, K. F.

    1973-01-01

    Preparations of formaldehyde in various organic liquids - ethylene glycol, glycerol, and propylene glycol - serve as effective disinfectants towards microbial vegetative cells and spores. This disinfection is a temperature-dependent process and is manifest when these formaldehyde base disinfectants are dissolved in water. The irritating vapors associated with formaldehyde disinfection are not present in either of these new formaldehyde base disinfectants or in aqueous solutions of them.

  6. Electronic multi-purpose material level sensor

    DOEpatents

    McEwan, Thomas E.

    1997-01-01

    The present electronic multi-purpose material level sensor is based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line that is partially immersed in a liquid, powder, or other substance such as grain in a silo. The time difference of the reflections at the start of the transmission line and the air/liquid interface are used to determine levels to better than 0.01 inch. The sensor is essentially independent of circuit element and temperature variations, and can be mass produced at an extremely low price. The transmission line may be a Goubau line, microstrip, coaxial cable, twin lead, CPS or CPW, and may typically be a strip placed along the inside wall of a tank. The reflected pulses also contain information about strata within the liquid such as sludge-build-up at the bottom of an oil tank.

  7. Electronic multi-purpose material level sensor

    DOEpatents

    McEwan, T.E.

    1997-03-11

    The present electronic multi-purpose material level sensor is based on time domain reflectometry (TDR) of very short electrical pulses. Pulses are propagated along a transmission line that is partially immersed in a liquid, powder, or other substance such as grain in a silo. The time difference of the reflections at the start of the transmission line and the air/liquid interface are used to determine levels to better than 0.01 inch. The sensor is essentially independent of circuit element and temperature variations, and can be mass produced at an extremely low price. The transmission line may be a Goubau line, microstrip, coaxial cable, twin lead, CPS or CPW, and may typically be a strip placed along the inside wall of a tank. The reflected pulses also contain information about strata within the liquid such as sludge-build-up at the bottom of an oil tank. 9 figs.

  8. Targeting cyst wall is an effective strategy in improving the efficacy of marketed contact lens disinfecting solutions against Acanthamoeba castellanii cysts.

    PubMed

    Abjani, Farhat; Khan, Naveed Ahmed; Yousuf, Farzana Abubakar; Siddiqui, Ruqaiyyah

    2016-06-01

    Acanthamoeba cysts are highly resistant to contact lens disinfecting solutions. Acanthamoeba cyst wall is partially made of 1,4 β-glucan (i.e., cellulose) and other complex polysaccharides making it a hardy shell that protects the resident amoeba. Here, we hypothesize that targeting the cyst wall structure in addition to antiamoebic compound would improve the efficacy of marketed contact lens disinfecting solutions. Using chlorhexidine as an antiamoebic compound and cellulase enzyme to disrupt cyst wall structure, the findings revealed that combination of both agents abolished viability of Acanthamoeba castellanii cysts and trophozoites. When tested alone, none of the agents nor contact lens disinfecting solutions completely destroyed A. castellanii cysts and trophozoites. The absence of cyst wall-degrading enzymes in marketed contact lens disinfecting solutions render them ineffective against Acanthamoeba cysts. It is concluded that the addition of cyst wall degrading molecules in contact lens disinfecting solutions will enhance their efficacy in decreasing the incidence of Acanthamoeba effectively. PMID:26675112

  9. Corrosive effect of disinfection solution containing hydroxyl radicals generated by photolysis of H(2)O(2) on dental metals.

    PubMed

    Nakamura, Keisuke; Yamada, Yasutomo; Takada, Yukyo; Mokudai, Takayuki; Ikai, Hiroyo; Inagaki, Ryoichi; Kanno, Taro; Sasaki, Keiichi; Kohno, Masahiro; Niwano, Yoshimi

    2012-01-01

    The purpose of the present study was to evaluate the corrosive effect of disinfection solution containing hydroxyl radicals generated by photolysis of H(2)O(2)on dental metals. Static immersion test was performed on four different dental metals: Ti, Type 316L stainless steel, Ag-Pd-Cu-Au alloy, and Co-Cr alloy. Metal specimens were immersed in 1 M H(2)O(2)(=3.4%) with or without light-emitting diode (LED) light irradiation (wavelength: 400 nm) for 1 week, and then the amounts of released ions were analyzed. Corrosive effect of the disinfection solution containing hydroxyl radicals on any dental metals tested in the present study never exceeded that of H(2)O(2) alone. Therefore, disinfection systems based on the photolysis of H(2)O(2) for the cleaning of dentures and treatment of oral infectious diseases would not cause problematic metal corrosion whenever the concentration of H(2)O(2) does not exceed 3%, which is a concentration used as an oral disinfectant. PMID:23207198

  10. [Disinfection efficacy of hand hygiene based on chlorhexidine gluconate content and usage of alcohol-based hand-rubbing solution].

    PubMed

    Tanaka, Ippei; Watanabe, Kiyoshi; Nakaminami, Hidemasa; Azuma, Chihiro; Noguchi, Norihisa

    2014-01-01

    Recently, the procedure for surgical hand hygiene has been switching to a two-stage method and hand-rubbing method from the traditional hand-scrubbing method. Both the two-stage and hand-rubbing methods use alcohol-based hand-rubbing after hand washing. The former requires 5 min of antiseptic hand washing, and the latter 1 min of nonantiseptic hand washing. For a prolonged bactericidal effect in terms of surgical hand hygiene, chlorhexidine gluconate (CHG) has been noted due to its residual activity. However, no detailed study comparing the disinfection efficacy and prolonged effects according to different contents of CHG and the usage of alcohol-based hand-rubbing has been conducted. The glove juice method is able to evaluate disinfection efficacy and prolonged effects of the disinfectants more accurately because it can collect not only transitory bacteria but also normal inhabitants on hands. In the present study, we examined the disinfection efficacy and prolonged effects on alcohol-based hand-rubbing containing CHG by six hand-rubbing methods and three two-stage methods using the glove juice method. In both methods, 3 mL (one pump dispenser push volume) alcohol-based hand-rubbing solution containing 1% (w/v) CHG showed the highest disinfection efficacy and prolonged effects, and no significant difference was found between the hand-rubbing and two-stage methods. In the two methods of hand hygiene, the hand-rubbing method was able to save time and cost. Therefore, the data strongly suggest that the hand-rubbing method using a one pump dispenser push volume of alcohol-based hand-rubbing solution containing 1% (w/v) CHG is suitable for surgical hand hygiene. PMID:25366919

  11. Evaluation of safety and efficacy of a new multipurpose disinfecting solution on silicone hydrogel contact lenses☆

    PubMed Central

    Pinto-Fraga, José; Blázquez Arauzo, Francisco; Urbano Rodríguez, Rubén; González-García, María J.

    2014-01-01

    Purpose To evaluate the safety and efficacy of a new multipurpose disinfecting solution (MPDS) with a formulation that includes aloe vera on its composition. Methods This is a prospective, randomized, double-masked clinical trial with a crossover design that included seven examinations. Two different MPDSs, Avizor Alvera® (study solution) and All Clean Soft® (control solution), each were used for 1 month. Comfilcon A silicone hydrogel contact lenses were used during the trial. The main outcome variables were corneal staining and deposits on the surfaces of the contact lenses. Other parameters including ocular surface response, contact lens wettability, user satisfaction, and adverse events, were analyzed according to the International Organization for Standardization (ISO) 11980:2010 guidance for clinical investigation. Results Twenty subjects (10 women, 10 men) (mean age, 27.7 ± 5.6 years; range, 20–41) were included. No differences between both MPDSs were found in the percentage of subjects with corneal staining >0 at day 30 (study: 35%, control: 50%; p = 0.46); neither in the percentage of subjects with deposits on the surface of the contact lens >0 at day 30 (study: 26.32%, control: 52.63%; p = 0.18). The study MPDS received higher rates in comfort (study: 8.14 ± 1.09, control: 7.94 ± 0.92; p = 0.56) and satisfaction at day 30 (study: 8.63 ± 0.91, control: 8.29 ± 0.80; p = 0.19), however the scores were not significantly different with the control MPDS. Conclusions The clinical trial showed that the study MPDS is safe, efficient, and has acceptable physiologic tolerance, according to the ISO 11980:2010 guidance for clinical investigation. PMID:25649640

  12. Multi-Purpose Logistics Module (MPLM) Cargo Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Zampiceni, John J.; Harper, Lon T.

    2002-01-01

    This paper describes the New Shuttle Orbiter's Multi- Purpose Logistics Modulo (MPLM) Cargo Heat Exchanger (HX) and associated MPLM cooling system. This paper presents Heat Exchanger (HX) design and performance characteristics of the system.

  13. Direct determination of peracetic acid, hydrogen peroxide, and acetic acid in disinfectant solutions by far-ultraviolet absorption spectroscopy.

    PubMed

    Higashi, Noboru; Yokota, Hiroshi; Hiraki, Satoru; Ozaki, Yukihiro

    2005-04-01

    In this paper we propose a rapid and highly selective far-ultraviolet (FUV) spectroscopic method for the simultaneous determination of peracetic acid (PAA), hydrogen peroxide, and acetic acid (AA). For this purpose we developed a novel FUV spectrometer that enables us to measure the spectra down to 180 nm. Direct determination of PAA, H(2)O(2), and AA, the three main species in disinfectant solutions, was carried out by using their absorption bands in the 180-220-nm region. The proposed method does not require any reagents or catalysts, a calibration standard, and a complicated procedure for the analysis. The only preparation procedure requested is a dilution of H(2)O(2) with pure water to a concentration range lower than 0.2 wt % in the sample solutions. Usually, the required concentration range can be obtained by the 10 times volume dilution of the actual disinfectant solutions. As the measured sample does not leave any impurity for the disinfection, it can be reused completely by using a circulation system. The detection limit for PAA of the new FUV spectrometer was evaluated to be 0.002 wt %, and the dynamic ranges of the measured concentrations were from 0 to 0.05 wt %, from 0 to 0.2 wt %, and from 0 to 0.2 wt % for PAA, H(2)O(2), and AA, respectively. The response time for the simultaneous determination of the three species is 30 s, and the analysis is applicable even to the flowing samples. This method may become a novel approach for the continuous monitoring of PAA in disinfectant solutions on the process of sterilization. PMID:15801764

  14. Performance of Three Multipurpose Disinfecting Solutions with a Silicone Hydrogel Contact Lens

    PubMed Central

    García-Porta, Nery; Rico-del-Viejo, Laura; Ferreira-Neves, Helena; Peixoto-de-Matos, Sofia C.; Queirós, Antonio; González-Méijome, José M.

    2015-01-01

    Purpose. To evaluate the clinical performance of a silicone hydrogel (Si-Hy) soft contact lens (CL) in combination with three different multipurpose disinfecting solutions (MPDSs). Methods. This was a prospective, randomized, single-masked, crossover, and comparative study in which 31 habitual soft CL wearers were randomly assigned to one of the three MPDSs (Synergi, COMPLETE RevitaLens, and OPTI-FREE PureMoist) for 1 month with a 1-week wash-out period between each exposure. All subjects were successfully refitted with a Si-Hy CL (Biofinity). Subjects were then scheduled for follow-up visits after 1 month of lens wear, being evaluated at 2 and 8 hours after lens insertion. Visual Analogue Scales (VAS) were used to gauge comfort rating. Results. The tarsal conjunctiva showed a significantly different degree of lid redness between the MPDSs at the 2-hour visit (P < 0.05, Kruskal-Wallis test), being lower for COMPLETE RevitaLens compared to the other two MPDSs (Mann-Whitney U test). Furthermore, a significantly different degree of lid roughness at the 8-hour visit was seen (P < 0.05, Kruskal-Wallis test), being higher for Synergi (Mann-Whitney U test). The subjective comfort was similar with the three MPDSs. Conclusion. Tarsal conjunctival response should be also considered in the context of the clinical performance of MPDs at the ocular surface. PMID:25918703

  15. Human resources for maternal health: multi-purpose or specialists?

    PubMed Central

    Fauveau, Vincent; Sherratt, Della R; de Bernis, Luc

    2008-01-01

    A crucial question in the aim to attain MDG5 is whether it can be achieved faster with the scaling up of multi-purpose health workers operating in the community or with the scaling up of professional skilled birth attendants working in health facilities. Most advisers concerned with maternal mortality reduction concur to promote births in facilities with professional attendants as the ultimate strategy. The evidence, however, is scarce on what it takes to progress in this path, and on the 'interim solutions' for situations where the majority of women still deliver at home. These questions are particularly relevant as we have reached the twentieth anniversary of the safe motherhood initiative without much progress made. In this paper we review the current situation of human resources for maternal health as well as the problems that they face. We propose seven key areas of work that must be addressed when planning for scaling up human resources for maternal health in light of MDG5, and finally we indicate some advances recently made in selected countries and the lessons learned from these experiences. Whilst the focus of this paper is on maternal health, it is acknowledged that the interventions to reduce maternal mortality will also contribute to significantly reducing newborn mortality. Addressing each of the seven key areas of work – recommended by the first International Forum on 'Midwifery in the Community', Tunis, December 2006 – is essential for the success of any MDG5 programme. We hypothesize that a great deal of the stagnation of maternal health programmes has been the result of confusion and careless choices in scaling up between a limited number of truly skilled birth attendants and large quantities of multi-purpose workers with short training, fewer skills, limited authority and no career pathways. We conclude from the lessons learnt that no significant progress in maternal mortality reduction can be achieved without a strong political decision to

  16. Influence of disinfectant solutions on test materials used for the determination of masticatory performance.

    PubMed

    Campos, Simone Silvério; Pereira, Cássio Vicente; Zangerônimo, Márcio Gilberto; Marques, Leandro Silva; Pereira, Luciano José

    2013-01-01

    Masticatory function can be evaluated objectively as the capacity of an individual to fragment solid food after a fixed number of chewing cycles, the so-called masticatory performance (MP). The objective of this study was to evaluate the reliability of four different test materials (Optosil, Optocal, Zetapuls, and Perfil) and five disinfection protocols by aspersion and immersion (no disinfection, 2% glutaraldehyde, 2% chlorhexidine, 5.25% sodium hypochlorite, and 70% alcohol) on the MP, determined at three moments (24 hours, 15 and 60 days) after storing the fragmented blocks. MP was evaluated by calculating X50 through the sieving technique and the Rosim-Ramler equation. The weight and microbiologic count (colony forming units, CFUs) of chewed blocks were measured to identify any variations that would make MP determination unfeasible. Differences in MP were observed among the materials (p < 0.01). Perfil presented the highest X50 value (worst MP determination), followed by Zetaplus (both p < 0.05), Optosil, and Optocal (both p > 0.05). The time and disinfection type had no influence on MP (p > 0.05). The number of CFUs differed between the nondisinfected group and all other disinfection groups at all time points (p < 0.01). No other significant difference in CFU count between disinfection groups was observed. In conclusion, disinfection did not alter the reliability of the test materials for the MP calculation for up to 60 days. PMID:23657488

  17. [Disinfection of water: on the need for analysis and solution of fundamental and applied problems].

    PubMed

    Mokienko, A V

    2014-01-01

    In the paper there is presented an analysis of hygienic--medical and environmental aspects of water disinfection as exemplified of chlorine and chlorine dioxide (CD). The concept of persistent multivariate risk for aquatic pathogens, the own vision of the mechanism of formation of chlorine resistance of bacteria under the influence of biocides based on a two-step process of information and spatial interaction of the receptor and the substrate, the hypothesis of hormetic stimulating effect of residual active chlorine (in the complex with other factors) on the growth of aquatic pathogens have been proposed. The aggravation of the significance of halogen containing compounds (HCC) as byproducts of water chlorination in terms of their potential danger as toxicants and carcinogens has been substantiated. Analysis of hygienic and medical and environmental aspects of the use of chlorine dioxide as a means of disinfection of water allowed to justify chemism of its biocidal effect and mechanisms of bactericidal, virucidal, protozoocidal, sporicidal, algacidal actions, removal of biofilms, formation of disinfection byproducts. Chlorine dioxide was shown both to provide epidemic safety of drinking water due to its high virucidal, bactericidal and mycocidal action and to be toxicologically harmless in the context of the influence on the organism of laboratory animals as well as in relation to aquatic organisms under the discharge of disinfected wastewater. There has proved the necessity of the close relationship of fundamental and applied research in performing the first in terms of depth study of microbiological, molecular genetic and epidemiological problems of disinfection (chlorination) of water and the implementation of the latters by means of the introduction of alternative, including combined, technologies for water treatment and disinfection. PMID:24749274

  18. Disinfection Processes.

    PubMed

    Munakata, Naoko; Kuo, Jeff

    2016-10-01

    A review of the literature published in 2015 on topics relating to disinfection processes is presented. This review is divided into the following sections: disinfection methods, disinfection byproducts, and microbiology and microbial communities. PMID:27620087

  19. OCRWM Bulletin: Westinghouse begins designing multi-purpose canister

    SciTech Connect

    1995-09-01

    This publication consists of two parts: OCRWM (Office of Civilian Radioactive Waste Management) Bulletin; and Of Mountains & Science which has articles on the Yucca Mountain project. The OCRWM provides information about OCRWM activities and in this issue has articles on multi-purpose canister design, and transportation cask trailer.

  20. Disinfective process of strongly acidic electrolyzed product of sodium chloride solution against Mycobacteria.

    PubMed

    Yamamoto, Tomoyo Matsushita; Nakano, Takashi; Yamaguchi, Masaki; Shimizu, Mitsuhide; Wu, Hong; Aoki, Hiroaki; Ota, Rie; Kobayashi, Toyohide; Sano, Kouichi

    2012-12-01

    Electrolyzed acid water (EAW) has been studied for its disinfective potential against pathogenic microbes; however, the bactericidal process against Mycobacteria has not been clearly presented. In this study, to clarify the disinfective process against Mycobacteria, EAW-treated bacteria were examined against laboratory strains of Mycobacterium bovis (M. bovis), Mycobacterium smegmatis (M. smegmatis), and Mycobacterium terrae (M. terrae) by recovery culture and observation of morphology, enzymatic assay, and the detection of DNA. All experiments were performed with the use of EAW containing 30 ppm free chlorine that kills Mycobacteria, including three pathogenic clinical isolates of Mycobacterium tuberculosis (M. tuberculosis) and six isolates of other Mycobacteria, within 5 min. In morphology, the bacterial surface became rough, and a longitudinal concavity-like structure appeared. The intrabacterial enzyme of EAW-contacted bacteria was inactivated, but chromosomal DNA was not totally denatured. These results suggest that the bactericidal effect of EAW against Mycobacteria occurs by degradation of the cell wall, followed by denaturation of cytoplasmic proteins, but degeneration of the nucleic acid is not always necessary. PMID:23224598

  1. The Multi-Purpose Detector (MPD) of the collider experiment

    NASA Astrophysics Data System (ADS)

    Golovatyuk, V.; Kekelidze, V.; Kolesnikov, V.; Rogachevsky, O.; Sorin, A.

    2016-08-01

    The project NICA (Nuclotron-based Ion Collider fAcility) is aimed to study dense baryonic matter in heavy-ion collisions in the energy range up to √{s_{NN}} = 11 GeV with average luminosity of L = 1027 cm-2s-1 (for 197Au79). The experimental program at the NICA collider will be performed with the Multi-Purpose Detector (MPD). We report on the main physics objectives of the NICA heavy-ion program and present the main detector components.

  2. System Engineering Strategy for Distributed Multi-Purpose Simulation Architectures

    NASA Technical Reports Server (NTRS)

    Bhula, Dlilpkumar; Kurt, Cindy Marie; Luty, Roger

    2007-01-01

    This paper describes the system engineering approach used to develop distributed multi-purpose simulations. The multi-purpose simulation architecture focuses on user needs, operations, flexibility, cost and maintenance. This approach was used to develop an International Space Station (ISS) simulator, which is called the International Space Station Integrated Simulation (ISIS)1. The ISIS runs unmodified ISS flight software, system models, and the astronaut command and control interface in an open system design that allows for rapid integration of multiple ISS models. The initial intent of ISIS was to provide a distributed system that allows access to ISS flight software and models for the creation, test, and validation of crew and ground controller procedures. This capability reduces the cost and scheduling issues associated with utilizing standalone simulators in fixed locations, and facilitates discovering unknowns and errors earlier in the development lifecycle. Since its inception, the flexible architecture of the ISIS has allowed its purpose to evolve to include ground operator system and display training, flight software modification testing, and as a realistic test bed for Exploration automation technology research and development.

  3. 16 CFR 1212.3 - Requirements for multi-purpose lighters.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Requirements for multi-purpose lighters. 1212.3 Section 1212.3 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS SAFETY STANDARD FOR MULTI-PURPOSE LIGHTERS Requirements for Child-Resistance § 1212.3 Requirements for multi-purpose lighters. (a)...

  4. [The role of bacterial contamination of milking utensils and disinfecting solutions as a possible cause of clinical mastitis in dairy cows].

    PubMed

    Hässig, M; Sigrist, S M; Corti, S; Giezendanner, N; Stephan, R

    2011-06-01

    Various instruments and utensils used during milking as well as teat dip solutions were examined for contamination with coagulase-negative staphylococci (CNS). The goal of this study was to investigate the relationship between contaminated fomites and udder infection in dairy cows. A total of 344 cows from ten dairy farms with the highest rate of clinical mastitis among the farms serviced by the Ambulatory Clinic of the University of Zurich were included in the study. Each farm was visited five times. All lactating cows, with the exception of those undergoing antibiotic treatment, were examined immediately before milking using the California Mastitis Test (CMT). A milk sample was collected from positive quarters. Items used to clean the udder, which included wood wool, paper towels and disinfecting towels as well as the milker's hands and the teat dip cup were swabbed for bacteriological examination. Water samples, samples of teat dip and cleaning solutions were also collected and cultured. Our results demonstrate that cleaning and disinfecting solutions have the potential to transmit udder pathogens and cause clinical mastitis. The most common CNS isolated from quarter samples were S. saprophyticus, S. sciuri and S. chromogenes, and the most common CNS isolated from utensils, cleaning and disinfecting solutions were S. fleuretii, S. vitulus, S. equorum, S. sciuri, S. haemolyticus, S. succinus and S. saprophyticus. PMID:21638262

  5. 9 CFR 96.14 - Uncertified casings; disinfection with saturated brine solution.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... is necessary to agitate the solution occasionally by moving the casings. The tip of the recording thermometer should be located at a point which would be approximately at the bottom of the volume of...

  6. A Multi-purpose Brain-Computer Interface Output Device

    PubMed Central

    Thompson, David E; Huggins, Jane E

    2012-01-01

    While brain-computer interfaces (BCIs) are a promising alternative access pathway for individuals with severe motor impairments, many BCI systems are designed as standalone communication and control systems, rather than as interfaces to existing systems built for these purposes. While an individual communication and control system may be powerful or flexible, no single system can compete with the variety of options available in the commercial assistive technology (AT) market. BCIs could instead be used as an interface to these existing AT devices and products, which are designed for improving access and agency of people with disabilities and are highly configurable to individual user needs. However, interfacing with each AT device and program requires significant time and effort on the part of researchers and clinicians. This work presents the Multi-Purpose BCI Output Device (MBOD), a tool to help researchers and clinicians provide BCI control of many forms of AT in a plug-and-play fashion, i.e. without the installation of drivers or software on the AT device, and a proof-of-concept of the practicality of such an approach. The MBOD was designed to meet the goals of target device compatibility, BCI input device compatibility, convenience, and intuitive command structure. The MBOD was successfully used to interface a BCI with multiple AT devices (including two wheelchair seating systems), as well as computers running Windows (XP and 7), Mac and Ubuntu Linux operating systems. PMID:22208120

  7. A multi-purpose brain-computer interface output device.

    PubMed

    Thompson, David E; Huggins, Jane E

    2011-10-01

    While brain-computer interfaces (BCIs) are a promising alternative access pathway for individuals with severe motor impairments, many BCI systems are designed as stand-alone communication and control systems, rather than as interfaces to existing systems built for these purposes. An individual communication and control system may be powerful or flexible, but no single system can compete with the variety of options available in the commercial assistive technology (AT) market. BCls could instead be used as an interface to these existing AT devices and products, which are designed for improving access and agency of people with disabilities and are highly configurable to individual user needs. However, interfacing with each AT device and program requires significant time and effort on the part of researchers and clinicians. This work presents the Multi-Purpose BCI Output Device (MBOD), a tool to help researchers and clinicians provide BCI control of many forms of AT in a plug-and-play fashion, i.e., without the installation of drivers or software on the AT device, and a proof-of-concept of the practicality of such an approach. The MBOD was designed to meet the goals of target device compatibility, BCI input device compatibility, convenience, and intuitive command structure. The MBOD was successfully used to interface a BCI with multiple AT devices (including two wheelchair seating systems), as well as computers running Windows (XP and 7), Mac and Ubuntu Linux operating systems. PMID:22208120

  8. Multi-purpose hydrogen isotopes separation plant design

    SciTech Connect

    Boniface, H.A.; Gnanapragasam, N.V.; Ryland, D.K.; Suppiah, S.; Castillo, I.

    2015-03-15

    There is a potential interest at AECL's Chalk River Laboratories to remove tritium from moderately tritiated light water and to reclaim tritiated, downgraded heavy water. With only a few limitations, a single CECE (Combined Electrolysis and Catalytic Exchange) process configuration can be designed to remove tritium from heavy water or light water and upgrade heavy water. Such a design would have some restrictions on the nature of the feed-stock and tritium product, but could produce essentially tritium-free light or heavy water that is chemically pure. The extracted tritium is produced as a small quantity of tritiated heavy water. The overall plant capacity is fixed by the total amount of electrolysis and volume of catalyst. In this proposal, with 60 kA of electrolysis a throughput of 15 kg*h{sup -1} light water for detritiation, about 4 kg*h{sup -1} of heavy water for detritiation and about 27 kg*h{sup -1} of 98% heavy water for upgrading can be processed. Such a plant requires about 1,000 liters of AECL isotope exchange catalyst. The general design features and details of this multi-purpose CECE process are described in this paper, based on some practical choices of design criteria. In addition, we outline the small differences that must be accommodated and some compromises that must be made to make the plant capable of such flexible operation. (authors)

  9. STS-102 Onboard Photograph-Multi-Purpose Logistics Module, Leonardo

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A crewmember of Expedition One, cosmonaut Yuri P. Gidzenko, is dwarfed by transient hardware aboard Leonardo, the Italian Space Agency-built Multi-Purpose Logistics Module (MPLM), a primary cargo of the STS-102 mission. The Leonardo MPLM is the first of three such pressurized modules that will serve as the International Space Station's (ISS's) moving vans, carrying laboratory racks filled with equipment, experiments and supplies to and from the Space Station aboard the Space Shuttle. The cylindrical module is approximately 21-feet long and 15- feet in diameter, weighing almost 4.5 tons. It can carry up to 10 tons of cargo into 16 standard Space Station equipment racks. Of the 16 racks the module can carry, 5 can be furnished with power, data, and fluid to support refrigerators or freezers. In order to function as an attached station module as well as a cargo transport, the logistics module also includes components that provide life support, fire detection and suppression, electrical distribution, and computer functions. The eighth Shuttle mission to visit the ISS, the STS-102 mission served as a crew rotation flight. It delivered the Expedition Two crew to the Station and returned the Expedition One crew back to Earth.

  10. Development of multi-purpose MW gyrotrons for fusion devices

    NASA Astrophysics Data System (ADS)

    Minami, R.; Kariya, T.; Imai, T.; Numakura, T.; Endo, Y.; Nakabayashi, H.; Eguchi, T.; Shimozuma, T.; Kubo, S.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Mutoh, T.; Ito, S.; Idei, H.; Zushi, H.; Yamaguchi, Y.; Sakamoto, K.; Mitsunaka, Y.; the GAMMA 10 Group

    2013-06-01

    The latest development achievements in the University of Tsukuba of over-1 MW power level gyrotrons required in present-day fusion devices, GAMMA 10, Large Helical Device (LHD), QUEST, Heliotron J and NSTX, are presented. The obtained maximum outputs are 1.9 MW for 0.1 s on the 77 GHz LHD tube and 1.2 MW for 1 ms on the 28 GHz GAMMA 10 one, which are new records in these frequency ranges. In long-pulse operation, 0.3 MW for 40 min at 77 GHz and 0.54 MW for 2 s at 28 GHz are achieved. A new programme of 154 GHz 1 MW development has started for high-density plasma heating in LHD. On the first 154 GHz tube, 1.0 MW for 1 s is achieved. As a next activity of the 28 GHz gyrotron, an over-1.5 MW gyrotron is designed and fabricated to study the multi-MW oscillation. The possibility of 0.4 MW continuous wave and 2 MW level output in operations of a few seconds, after the improvements of output window and mode converter, is shown. Moreover, a new design study of dual-frequency gyrotron at 28 and 35 GHz has started, which indicates the practicability of the multi-purpose gyrotron.

  11. Stability of antimicrobial activity of peracetic acid solutions used in the final disinfection process.

    PubMed

    Costa, Solange Alves da Silva; Paula, Olívia Ferreira Pereira de; Silva, Célia Regina Gonçalves E; Leão, Mariella Vieira Pereira; Santos, Silvana Soléo Ferreira dos

    2015-01-01

    The instruments and materials used in health establishments are frequently exposed to microorganism contamination, and chemical products are used before sterilization to reduce occupational infection. We evaluated the antimicrobial effectiveness, physical stability, and corrosiveness of two commercial formulations of peracetic acid on experimentally contaminated specimens. Stainless steel specimens were contaminated with Staphylococcus aureus, Escherichia coli, Candida albicans, blood, and saliva and then immersed in a ready peracetic acid solution: 2% Sekusept Aktiv (SA) or 0.25% Proxitane Alpha (PA), for different times. Then, washes of these instruments were plated in culture medium and colony-forming units counted. This procedure was repeated six times per day over 24 non-consecutive days. The corrosion capacity was assessed with the mass loss test, and the concentration of peracetic acid and pH of the solutions were measured with indicator tapes. Both SA and PA significantly eliminated microorganisms; however, the SA solution was stable for only 4 days, whereas PA remained stable throughout the experiment. The concentration of peracetic acid in the SA solutions decreased over time until the chemical was undetectable, although the pH remained at 5. The PA solution had a concentration of 500-400 mg/L and a pH of 2-3. Neither formulation induced corrosion and both reduced the number of microorganisms (p = 0.0001). However, the differences observed in the performance of each product highlight the necessity of establishing a protocol for optimizing the use of each one. PMID:25715037

  12. Safety Assessment of Multi Purpose Small Payload Rack(MSPR)

    NASA Astrophysics Data System (ADS)

    Mizutani, Yoshinobu; Takada, Satomi; Murata, Kosei; Ozawa, Daisaku; Kobayashi, Ryoji; Nakamura, Yasuhiro

    2010-09-01

    We are reporting summary of preliminary safety assessment for Multi Purpose Small Payload Rack(MSPR), which is one of the micro gravity experiment facilities that are being developed for the 2nd phase JEM utilization(JEM: Japanese Experiment Module) that will be launched on H-II Transfer Vehicle(HTV) 2nd flight in 2011. MSPR is used for multi-purpose micro-g experiment providing experimental spaces and work stations. MSPR has three experimental spaces; first, there is a space called Work Volume(WV) with capacity volume of approximately 350 litters, in which multiple resources including electricity, communication, and moving image functions can be used. Within this space, installation of devices can be done by simple, prompt attachment by Velcro and pins with high degree of flexibility. Second, there is Small Experiment Area(SEA), with capacity volume of approximately 70 litters, in which electricity, communication, and moving image functions can also be used in the same way as WV. These spaces protect experiment devices and specimens from contingent loads by the crewmembers. Third, there is Work Bench with area of 0.5 square meters, on which can be used for maintenance, inspection and data operations of installed devices, etc. This bench can be stored in the rack during contingency. Chamber for Combustion Experiment(CCE) that is planned to be installed in WV is a pressure-resistant experimental container that can be used to seal hazardous materials from combustion experiments. This CCE has double sealing design in chamber itself, which resist gas leakage under normal the temperature and pressure. Electricity, communication, moving image function can be used in the same way as WV. JAXA Phase 2 Safety Review Panel(SRP) has been held in April, 2010. For safety analysis of MSPR, hazards were identified based on Fault Tree Analysis methodology and then these hazards were classified into either eight ISS standard-type hazards or eight unique-type hazards that requires

  13. Multi-Purpose Reefs - A Decade of Application

    NASA Astrophysics Data System (ADS)

    Mead, S.; Borrero, J. C.; Hearin, J.

    2011-12-01

    Offshore submerged structures for coastal protection and artificial reefs for enhancing local marine biodiversity and/or attracting sea life have been utilized for centuries. Indeed, the first known use of artificial reef structures for habitat enhancement dates back to 2000 BC on the south west coast of India. However, it was not until the 1960's that multi- purpose reefs (MPRs) intended combine coastal protection, eco-enhancement and surfing were first proposed. Through the 1970's and 1980's the concept of MPR's was advanced through the seminal works of James 'Kimo' Walker who pioneered the area of surfing science and developed the first methods for quantification of a surfing break. Design studies for artificial reefs primarily for surfing were undertaken for the construction of the world's first artificial surfing reef built in Perth in 1998, as well as for artificial reefs in California and the Queensland Gold Coast MPR in Australia. More than a decade on, seven reefs have now been constructed at locations around the world with differing levels of success. and a great deal has been learned about the functionality of and potential applications for these structures. This poster provides a brief update on the performance of these structures, summarizing the large volume of monitoring data available for many of these projects. This includes data on shoreline protection and beach response, ecological enhancement, habitat restoration and improvement of recreational amenities. We discuss several projects with respect to the above topics as well as some of the lessons learned in the light of future MPR developments. This poster considers the performance of MPR's in three primary areas of functionality: coastal protection, ecological enhancement and surfing enhancement. We also discuss some of the lessons learned and applied as understanding of these structures has increased.

  14. Choosing disinfectants.

    PubMed

    Fraise, A P

    1999-12-01

    Disinfectant choice is an important part of the role of the infection control team. Its importance has increased due to concern over transmission of blood-borne viruses and the need to identify alternatives to gluteraldehyde. Factors to be taken into account when choosing disinfectants include compliance with COSHH regulations, user acceptability, instrument compatibility and antimicrobial activity. Compounds vary in their suitability for different uses and an agent's properties must be fully evaluated before adopting it for a particular purpose. This review outlines the main properties that need to be established and covers the major characteristics of main classes of disinfectants. PMID:10658801

  15. A new NASA LaRC Multi-Purpose Prepregging Unit

    NASA Technical Reports Server (NTRS)

    Wilkinson, S. P.; Marchello, J. M.; Dixon, D.; Johnston, N. J.

    1993-01-01

    A multi-purpose prepregging machine has been designed and built for NASA Langley Research Center. The machine has numerous advantages over existing units due to its various modular components. Each of these can be used individually or simultaneously depending on the required prepregging method. A reverse roll coater provides the ability to prepare thin films from typical hot-melt thermoset formulations. Also, if necessary, the design allows direct fiber impregnation within the reverse roll coater gap. Included in the impregnation module is a solution dip tank allowing the fabrication of thermoplastic prepregs from solution. The proceeding modules within the unit consist of four nip stations, two hot-plates, a hot-sled option and a high temperature oven. This paper describes the advantages of such a modular construction and discusses the various processing combinations available to the prepregger. A variety of high performance prepreg material systems were produced on IM7 (Hercules) carbon fiber. These included LaRC RP46, a PMR-type resin processed from methanol and two polyamide acids, LaRC IA and LaRC ITPI, prpregged from N-methyl pyrrolidinone (NMP). Parameters involved in the production of these prepreg materials are presented as are the mechanical properties of the resulting good quality laminates. A brief introduction into the existing prepregging science is presented. Topics relating to solution prepregging are identified with a focus on the current research effort and its future development.

  16. Multi-criteria objective based climate change impact assessment for multi-purpose multi-reservoir systems

    NASA Astrophysics Data System (ADS)

    Müller, Ruben; Schütze, Niels

    2014-05-01

    Water resources systems with reservoirs are expected to be sensitive to climate change. Assessment studies that analyze the impact of climate change on the performance of reservoirs can be divided in two groups: (1) Studies that simulate the operation under projected inflows with the current set of operational rules. Due to non adapted operational rules the future performance of these reservoirs can be underestimated and the impact overestimated. (2) Studies that optimize the operational rules for best adaption of the system to the projected conditions before the assessment of the impact. The latter allows for estimating more realistically future performance and adaption strategies based on new operation rules are available if required. Multi-purpose reservoirs serve various, often conflicting functions. If all functions cannot be served simultaneously at a maximum level, an effective compromise between multiple objectives of the reservoir operation has to be provided. Yet under climate change the historically preferenced compromise may no longer be the most suitable compromise in the future. Therefore a multi-objective based climate change impact assessment approach for multi-purpose multi-reservoir systems is proposed in the study. Projected inflows are provided in a first step using a physically based rainfall-runoff model. In a second step, a time series model is applied to generate long-term inflow time series. Finally, the long-term inflow series are used as driving variables for a simulation-based multi-objective optimization of the reservoir system in order to derive optimal operation rules. As a result, the adapted Pareto-optimal set of diverse best compromise solutions can be presented to the decision maker in order to assist him in assessing climate change adaption measures with respect to the future performance of the multi-purpose reservoir system. The approach is tested on a multi-purpose multi-reservoir system in a mountainous catchment in Germany. A

  17. AVCOAT Density Characterization for Orion Multi-Purpose Crew Vehicle (MPCV)

    NASA Astrophysics Data System (ADS)

    Rodriguez, E. D.; Santos, J. A.; Bose, D.; Vander Kam, J.

    2014-06-01

    Post flight TPS analysis will be conducted on the Orion Multi-Purpose Crew Vehicle. The material characterization includes density profiling through the AVCOAT TPS thickness. Results help to further development more accurate TPS response models.

  18. Earthscape, a Multi-Purpose Interactive 3d Globe Viewer for Hybrid Data Visualization and Analysis

    NASA Astrophysics Data System (ADS)

    Sarthou, A.; Mas, S.; Jacquin, M.; Moreno, N.; Salamon, A.

    2015-08-01

    The hybrid visualization and interaction tool EarthScape is presented here. The software is able to display simultaneously LiDAR point clouds, draped videos with moving footprint, volume scientific data (using volume rendering, isosurface and slice plane), raster data such as still satellite images, vector data and 3D models such as buildings or vehicles. The application runs on touch screen devices such as tablets. The software is based on open source libraries, such as OpenSceneGraph, osgEarth and OpenCV, and shader programming is used to implement volume rendering of scientific data. The next goal of EarthScape is to perform data analysis using ENVI Services Engine, a cloud data analysis solution. EarthScape is also designed to be a client of Jagwire which provides multisource geo-referenced video fluxes. When all these components will be included, EarthScape will be a multi-purpose platform that will provide at the same time data analysis, hybrid visualization and complex interactions. The software is available on demand for free at france@exelisvis.com.

  19. MODELING DISINFECTANT RESIDUALS IN DRINKING-WATER STORAGE TANKS

    EPA Science Inventory

    The factors leading to the loss of disinfectant residual in well-mixed drinking-water storage tanks are studied. quations relating disinfectant residual to the disinfectant's reaction rate, the tank volume, and the fill and drain rates are presented. n analytical solution for the...

  20. MODELING DISINFECTANT RESIDUALS IN DRINKING-WATER STORAGE TANKS

    EPA Science Inventory

    The factors leading to the loss of disinfectant residual in well-mixed drinking-water storage tanks are studied. Equations relating disinfectant residual to the disinfectant's reation rate, the tank volume, and the fill and drain rates are presented. An analytical solution for ...

  1. Engineering a Multi-Purpose Test Collection for Web Retrieval Experiments.

    ERIC Educational Resources Information Center

    Bailey, Peter; Craswell, Nick; Hawking, David

    2003-01-01

    Describes a test collection that was developed as a multi-purpose testbed for experiments on the Web in distributed information retrieval, hyperlink algorithms, and conventional ad hoc retrieval. Discusses inter-server connectivity, integrity of server holdings, inclusion of documents related to a wide spread of likely queries, and distribution of…

  2. Monitored Retrievable Storage/Multi-Purpose Canister analysis: Simulation and economics of automation

    SciTech Connect

    Bennett, P.C.; Stringer, J.B.

    1994-03-01

    Robotic automation is examined as a possible alternative to manual spent nuclear fuel, transport cask and Multi-Purpose canister (MPC) handling at a Monitored Retrievable Storage (MRS) facility. Automation of key operational aspects for the MRS/MPC system are analyzed to determine equipment requirements, through-put times and equipment costs is described. The economic and radiation dose impacts resulting from this automation are compared to manual handling methods.

  3. Multi-Purpose, Application-Centric, Scalable I/O Proxy Application

    Energy Science and Technology Software Center (ESTSC)

    2015-06-15

    MACSio is a Multi-purpose, Application-Centric, Scalable I/O proxy application. It is designed to support a number of goals with respect to parallel I/O performance testing and benchmarking including the ability to test and compare various I/O libraries and I/O paradigms, to predict scalable performance of real applications and to help identify where improvements in I/O performance can be made within the HPC I/O software stack.

  4. [Determining the volume of solution necessary for intraoperative disinfection lavage of the abdominal cavity in diffuse suppurative peritonitis].

    PubMed

    Nifant'ev, O E; Popov, A E; Voevodina, T V; Okolelova, E V

    1990-01-01

    The advantages of lavage of the abdominal cavity in diffuse purulent peritonitis by means of a developed device "Geyser" are shown. Changes in the bacterial contamination, toxicity and metabolite contents in the lavage solution and peritoneum depended on a volume of the fluid used. PMID:2338787

  5. Comparison of susceptibility of cystic-fibrosis-related and non-cystic-fibrosis-related Pseudomonas aeruginosa to chlorine-based disinfecting solutions: implications for infection prevention and ward disinfection.

    PubMed

    Moore, John E; Rendall, Jacqueline C

    2014-09-01

    Multidrug-resistant (MDR) Pseudomonas aeruginosa isolated from cystic fibrosis (CF) sputum was shown to be more tolerant to the most commonly used chlorine-based disinfecting agent in the UK, with approximately 7 out of 10 isolates surviving a residual free chlorine (RFC) concentration of 500 p.p.m., when compared with antibiotic-sensitive invasive P. aeruginosa from a non-CF blood culture source, where 8 out of 10 isolates were killed at a RFC concentration of 100 p.p.m. All CF isolates were killed at 1000 p.p.m. chlorine. Additional studies were performed to examine factors that influenced the concentration of RFC from chlorine-based (sodium dichloroisocyanurate) disinfecting agents in contact with CF sputum and their components (bacterial cells, glycocalyx) to assess the reduction of the bactericidal activity of such disinfecting agents. Pseudomonas glycocalyx had a greater inhibitory effect of chlorine deactivation than bacterial cells. Calibration curves demonstrated the relative deactivating capacity on RFC from clinical soils, in the order pus>CF sputum>wound discharge fluid/synovial fluid>ascites fluid>bile, where quantitatively each 1 % (w/v) CF sputum reduced the RFC by 43 p.p.m. Sublethal stressing of P. aeruginosa with chlorine resulted in lowered susceptibility to colistin (P = 0.0326) but not to meropenem, tobramycin or ciprofloxacin. In conclusion, heavy contamination of healthcare fomites with CF sputum containing MDR P. aeruginosa may result in exhaustion of RFC, and this, combined with an increased resistance to chlorine with such strains, may lead to their survival and increased antibiotic resistance in such environments. CF infection prevention strategies in such scenarios should therefore target interventions with increased concentrations of chlorine to ensure the eradication of MDR P. aeruginosa from the CF healthcare environment. PMID:24925907

  6. Restoring Natural Streamflow Variability by Modifying Multi-purpose Reservoir Operation

    NASA Astrophysics Data System (ADS)

    Shiau, J.

    2010-12-01

    Multi-purpose reservoirs typically provide benefits of water supply, hydroelectric power, and flood mitigation. Hydroelectric power generations generally do not consume water. However, temporal distribution of downstream flows is highly changed due to hydro-peaking effects. Associated with offstream diversion of water supplies for municipal, industrial, and agricultural requirements, natural streamflow characteristics of magnitude, duration, frequency, timing, and rate of change is significantly altered by multi-purpose reservoir operation. Natural flow regime has long been recognized a master factor for ecosystem health and biodiversity. Restoration of altered flow regime caused by multi-purpose reservoir operation is the main objective of this study. This study presents an optimization framework that modifying reservoir operation to seeking balance between human and environmental needs. The methodology presented in this study is applied to the Feitsui Reservoir, located in northern Taiwan, with main purpose of providing stable water-supply and auxiliary purpose of electricity generation and flood-peak attenuation. Reservoir releases are dominated by two decision variables, i.e., duration of water releases for each day and percentage of daily required releases within the duration. The current releasing policy of the Feitsui Reservoir releases water for water-supply and hydropower purposes during 8:00 am to 16:00 pm each day and no environmental flows releases. Although greater power generation is obtained by 100% releases distributed within 8-hour period, severe temporal alteration of streamflow is observed downstream of the reservoir. Modifying reservoir operation by relaxing these two variables and reserve certain ratio of streamflow as environmental flow to maintain downstream natural variability. The optimal reservoir releasing policy is searched by the multi-criterion decision making technique for considering reservoir performance in terms of shortage ratio

  7. Programmable Thermostat Module Upgrade for the Multi-Purpose Logistics Module

    NASA Technical Reports Server (NTRS)

    Clark, Dallas; Glasgow, Shaun; Reagan, Shawn; Presson, Keith; Howard, David; Smith, Dennis

    2007-01-01

    The STS-121/ULF1.1 mission was the maiden flight of the Programmable Thermostat Module (PTM) system used to control the 28 V shell heaters on the Multi-Purpose Logistics Module (MPLM). These PTMs, in conjunction with a Data Recorder Module (DRM), provide continuous closed loop temperature control and data recording of MPLM on-orbit heater operations. This paper will discuss the hardware design, development, test and verification (DDT&V) activities performed at the Marshall Space Flight Center (MSFC) as well as the operational implementation and mission performance.

  8. A multi-purpose SAIL demonstrator design and its principle experimental verification

    NASA Astrophysics Data System (ADS)

    Zhou, Yu; Yan, Aimin; Xu, Nan; Wang, Lijuan; Luan, Zhu; Sun, Jianfeng; Liu, Liren

    2009-08-01

    A fully 2-D synthetic aperture imaging ladar (SAIL) demonstrator is designed and being fabricated to experimentally investigate and theoretically analyze the beam diffraction properties, antenna function, imaging resolution and signal processing algorithm of SAIL. The design details of the multi-purpose SAIL demonstrator are given and, as the first phase, a laboratory-scaled SAIL system based on bulk optical elements has been built to verify the principle of design, which is similar in construction to the demonstrator but without the major antenna telescope. The system has the aperture diameter of about 1mm and the target distance of 3.2m.

  9. The Multi-Purpose Detector for NICA heavy-Ion Collider at JINR

    SciTech Connect

    Rogachevsky, O. V.

    2012-05-15

    The Multi-Purpose Detector (MPD) is designed to study heavy-ion collisions at the Nuclotron-based heavy Ion Collider fAcility (NICA) at JINR, Dubna. Its main components located inside a superconducting solenoid are a tracking system composed of a silicon microstrip vertex detector followed by a large volume time-projection chamber, a time-of-flight system for particle identification and a barrel electromagnetic calorimeter. A zero degree hadron calorimeter is designed specifically to measure the energy of spectators. In this paper, all parts of the apparatus are described and their tracking and particle identification parameters are discussed in some detail.

  10. [Skin and hand disinfection].

    PubMed

    Mathis, U

    1991-04-01

    In modern medicine, hygiene has become an issue of ever increasing importance. Disinfection of hands is crucial, since hands are the main vector of bacteria. Successful disinfection depends not only on the appropriate choice of an active agent, but equally so on proper techniques and skin care. The spectre and the time profile of activity as well as the skin-protecting properties of the chosen disinfectant must be known. Basic knowledge of disinfection is necessary for a rational interpretation of the information given in the glossy printed material of advertisement. PMID:1858061

  11. Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Hardware

    NASA Astrophysics Data System (ADS)

    Kang, Y.-W.; Byun, Y. I.; Rhee, J. H.; Oh, S. H.; Kim, D. K.

    2007-12-01

    We designed and developed a multi-purpose CCD camera system for three kinds of CCDs; KAF-0401E(768×512), KAF-1602E(1536×1024), KAF-3200E(2184×1472) made by KODAK Co.. The system supports fast USB port as well as parallel port for data I/O and control signal. The packing is based on two stage circuit boards for size reduction and contains built-in filter wheel. Basic hardware components include clock pattern circuit, A/D conversion circuit, CCD data flow control circuit, and CCD temperature control unit. The CCD temperature can be controlled with accuracy of approximately 0.4° C in the max. range of temperature, Δ 33° C. This CCD camera system has with readout noise 6 e^{-}, and system gain 5 e^{-}/ADU. A total of 10 CCD camera systems were produced and our tests show that all of them show passable performance.

  12. Multi Purpose Crew Vehicle Active Thermal Control and Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Boehm, Paul; Cross, Cynthia D.; Rains, George Edward

    2014-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in September of 2014. The development of the Orion Active Thermal Control (ATCS) and Environmental Control and Life Support (ECLS) System, focused on the integrating the components into the EFT1 vehicle and preparing them for launch. Work also has started on preliminary design reviews for the manned vehicle. Additional development work is underway to keep the remaining component progressing towards implementation on the flight tests of EM1 in 2017 and of EM2 in 2020. This paper covers the Orion ECLS development from April 2013 to April 2014

  13. Orion Multi Purpose Crew Vehicle Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Carrasquillo, Robyn; Rains, George Edward

    2012-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely from the Earth beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in 2014. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the components which are on EFT1 which includes pressure control and active thermal control systems, is progressing through the design stage into manufacturing. Additional development work was done to keep the remaining component progressing towards implementation for a flight tests in 2017 and in 2020. This paper covers the Orion ECLS development from April 2011 to April 2012.

  14. Controlling levonorgestrel binding and release in a multi-purpose prevention technology vaginal ring device.

    PubMed

    Murphy, Diarmaid J; Boyd, Peter; McCoy, Clare F; Kumar, Sandeep; Holt, Jonathon D S; Blanda, Wendy; Brimer, Andrew N; Malcolm, R Karl

    2016-03-28

    Despite a long history of incorporating steroids into silicone elastomers for drug delivery applications, little is presently known about the propensity for irreversible drug binding in these systems. In this study, the ability of the contraceptive progestin levonorgestrel to bind chemically with hydrosilane groups in addition-cure silicone elastomers has been thoroughly investigated. Cure time, cure temperature, levonorgestrel particle size, initial levonorgestrel loading and silicone elastomer type were demonstrated to be key parameters impacting the extent of levonorgestrel binding, each through their influence on the solubility of levonorgestrel in the silicone elastomer. Understanding and overcoming this levonorgestrel binding phenomenon is critical for the ongoing development of a number of drug delivery products, including a multi-purpose technology vaginal ring device offering simultaneous release of levonorgestrel and dapivirine - a lead candidate antiretroviral microbicide - for combination HIV prevention and hormonal contraception. PMID:26878974

  15. Descent and Landing Triggers for the Orion Multi-Purpose Crew Vehicle Exploration Flight Test-1

    NASA Technical Reports Server (NTRS)

    Bihari, Brian D.; Semrau, Jeffrey D.; Duke, Charity J.

    2013-01-01

    The Orion Multi-Purpose Crew Vehicle (MPCV) will perform a flight test known as Exploration Flight Test-1 (EFT-1) currently scheduled for 2014. One of the primary functions of this test is to exercise all of the important Guidance, Navigation, Control (GN&C), and Propulsion systems, along with the flight software for future flights. The Descent and Landing segment of the flight is governed by the requirements levied on the GN&C system by the Landing and Recovery System (LRS). The LRS is a complex system of parachutes and flight control modes that ensure that the Orion MPCV safely lands at its designated target in the Pacific Ocean. The Descent and Landing segment begins with the jettisoning of the Forward Bay Cover and concludes with sensing touchdown. This paper discusses the requirements, design, testing, analysis and performance of the current EFT-1 Descent and Landing Triggers flight software.

  16. The Raffaello, a Multi-Purpose Logistics Module, arrives at KSC aboard a Beluga super transporter

    NASA Technical Reports Server (NTRS)

    1999-01-01

    An Airbus Industrie A300-600ST 'Beluga' Super Transporter lands in the rain at the Shuttle Landing Facility to deliver its cargo, the second Multi-Purpose Logistics Module (MPLM) for the International Space Station (ISS). One of Italy's major contributions to the ISS program, the MPLM, named Raffaello, is a reusable logistics carrier and the primary delivery system used to resupply and return station cargo requiring a pressurized environment. Weighing nearly 4.5 tons, the module measures 21 feet long and 15 feet in diameter. Raffaello will join Leonardo, the first Italian-built MPLM, in the Space Station Processing Facility for testing. NASA, Boeing, the Italian Space Agency and Alenia Aerospazio will provide engineering support.

  17. The Raffaello, a Multi-Purpose Logistics Module, arrives at KSC aboard a Beluga super transporter

    NASA Technical Reports Server (NTRS)

    1999-01-01

    An Airbus Industrie A300-600ST 'Beluga' Super Transporter is reflected in the rain puddles as it taxis toward the mate/demate tower at the Shuttle Landing Facility. The Beluga is carrying the Raffaello, the second Multi-Purpose Logistics Module (MPLM) for the International Space Station (ISS). One of Italy's major contributions to the ISS program, the MPLM is a reusable logistics carrier and the primary delivery system used to resupply and return station cargo requiring a pressurized environment. Weighing nearly 4.5 tons, the module measures 21 feet long and 15 feet in diameter. Raffaello will join Leonardo, the first Italian-built MPLM, in the Space Station Processing Facility for testing. NASA, Boeing, the Italian Space Agency and Alenia Aerospazio will provide engineering support.

  18. The Raffaello, a Multi-Purpose Logistics Module, arrives at KSC aboard a Beluga super transporter

    NASA Technical Reports Server (NTRS)

    1999-01-01

    An Airbus Industrie A300-600ST 'Beluga' Super Transporter is reflected in the rain puddles as it comes to a stop at the Shuttle Landing Facility. The Beluga is carrying the Raffaello, the second Multi-Purpose Logistics Module (MPLM) for the International Space Station (ISS). One of Italy's major contributions to the ISS program, the MPLM is a reusable logistics carrier and the primary delivery system used to resupply and return station cargo requiring a pressurized environment. Weighing nearly 4.5 tons, the module measures 21 feet long and 15 feet in diameter. Raffaello will join Leonardo, the first Italian-built MPLM, in the Space Station Processing Facility for testing. NASA, Boeing, the Italian Space Agency and Alenia Aerospazio will provide engineering support.

  19. The Raffaello, a Multi-Purpose Logistics Module, arrives at KSC aboard a Beluga super transporter

    NASA Technical Reports Server (NTRS)

    1999-01-01

    An Airbus Industrie A300-600ST 'Beluga' Super Transporter touches down at the Shuttle Landing Facility to deliver its cargo, the second Multi-Purpose Logistics Module (MPLM) for the International Space Station (ISS). One of Italy's major contributions to the ISS program, the MPLM, named Raffaello, is a reusable logistics carrier and the primary delivery system used to resupply and return station cargo requiring a pressurized environment. Weighing nearly 4.5 tons, the module measures 21 feet long and 15 feet in diameter. Raffaello will join Leonardo, the first Italian-built MPLM, in the Space Station Processing Facility for testing. NASA, Boeing, the Italian Space Agency and Alenia Aerospazio will provide engineering support.

  20. Multi-Purpose Avionic Architecture for Vision Based Navigation Systems for EDL and Surface Mobility Scenarios

    NASA Astrophysics Data System (ADS)

    Tramutola, A.; Paltro, D.; Cabalo Perucha, M. P.; Paar, G.; Steiner, J.; Barrio, A. M.

    2015-09-01

    Vision Based Navigation (VBNAV) has been identified as a valid technology to support space exploration because it can improve autonomy and safety of space missions. Several mission scenarios can benefit from the VBNAV: Rendezvous & Docking, Fly-Bys, Interplanetary cruise, Entry Descent and Landing (EDL) and Planetary Surface exploration. For some of them VBNAV can improve the accuracy in state estimation as additional relative navigation sensor or as absolute navigation sensor. For some others, like surface mobility and terrain exploration for path identification and planning, VBNAV is mandatory. This paper presents the general avionic architecture of a Vision Based System as defined in the frame of the ESA R&T study “Multi-purpose Vision-based Navigation System Engineering Model - part 1 (VisNav-EM-1)” with special focus on the surface mobility application.

  1. Raffaello Multi-Purpose Logistics Module (MPLM) in Discovery Cargo Bay

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Launched on July 26 2005 from the Kennedy Space Center in Florida, STS-114 was classified as Logistics Flight 1. Among the Station-related activities of the mission were the delivery of new supplies and the replacement of one of the orbital outpost's Control Moment Gyroscopes (CMGs). STS-114 also carried the Raffaello Multi-Purpose Logistics Module (MPLM) and the External Stowage Platform-2. Back dropped by popcorn-like clouds, the MPLM can be seen in the cargo bay as Discovery undergoes rendezvous and docking operations. Cosmonaut Sergei K. Kriklev, Expedition 11 Commander, and John L. Phillips, NASA Space Station officer and flight engineer photographed the spacecraft from the International Space Station (ISS).

  2. Raffaello Multi-Purpose Logistics Module (MPLM) in Discovery Cargo Bay

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Launched on July 26, 2005 from the Kennedy Space Center in Florida, STS-114 was classified as Logistics Flight 1. Among the Station-related activities of the mission were the delivery of new supplies and the replacement of one of the orbital outpost's Control Moment Gyroscopes (CMGs). STS-114 also carried the Raffaello Multi-Purpose Logistics Module (MPLM) and the External Stowage Platform-2. Back dropped by popcorn-like clouds, the MPLM can be seen in the cargo bay as Discovery undergoes rendezvous and docking operations. Cosmonaut Sergei K. Kriklev, Expedition 11 Commander, and John L. Phillips, NASA Space Station officer and flight engineer photographed the spacecraft from the International Space Station (ISS).

  3. NASA AND ESA Partnership on the Multi-Purpose Crew Vehicle Service Module

    NASA Technical Reports Server (NTRS)

    Free, James M.; Schubert, Kathleen; Grantier, Julie

    2012-01-01

    In March 2011, NASA and ESA made a decision to partially offset the European obligations deriving from the extension of the ISS Program until the end of 2020 with different means than ATVs, following the ATV-5 mission foreseen in mid-2014. NASA and ESA considered a number of barter options, and concluded that the provision by ESA of the Service Module and Spacecraft Adaptor for the NASA Multi-Purpose Crew Vehicle (MPCV) was the barter element with the most interest. A joint ESA - NASA working group was established to assess the feasibility of Europe developing this Module based on ATV heritage. The working group was supported by European and US industry namely Astrium, TAS-I and Lockheed-Martin. This paper gives an overview of the results of the on-going study as well as its projected utilization for the global space exploration endeavour.

  4. Multi Purpose Crew Vehicle Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Carrasquillo, Robyn; Rains, George Edward

    2011-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely from the Earth beyond Earth orbit. This year, the vehicle focused on building the Orion Flight Test 1 (OFT1) vehicle to be launched in 2013. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the components which are on OFT1 which includes pressure control and active thermal control systems, is progressing through the design stage into manufacturing. Additional development work was done to keep the remaining component progressing towards implementation for a flight test in 2017. This paper covers the Orion ECLS development from April 2011 to April 2012.

  5. Multi Purpose Crew Vehicle Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Rains, George Edward

    2012-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in 2014. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the completing the components which are on EFT1. Additional development work has been done to keep the remaining component progressing towards implementation for a flight tests in of EM1 in 2017 and in and EM2 in 2020. This paper covers the Orion ECLS development from April 2012 to April 2013.

  6. Effectiveness of Four Disinfectants against Ebola Virus on Different Materials

    PubMed Central

    Smither, Sophie; Phelps, Amanda; Eastaugh, Lin; Ngugi, Sarah; O’Brien, Lyn; Dutch, Andrew; Lever, Mark Stephen

    2016-01-01

    The West Africa Ebola virus (EBOV) outbreak has highlighted the need for effective disinfectants capable of reducing viral load in a range of sample types, equipment and settings. Although chlorine-based products are widely used, they can also be damaging to equipment or apparatus that needs continuous use such as aircraft use for transportation of infected people. Two aircraft cleaning solutions were assessed alongside two common laboratory disinfectants in a contact kill assay with EBOV on two aircraft relevant materials representative of a porous and non-porous surface. A decimal log reduction of viral titre of 4 is required for a disinfectant to be deemed effective and two of the disinfectants fulfilled this criteria under the conditions tested. One product, Ardrox 6092, was found to perform similarly to sodium hypochlorite, but as it does not have the corrosive properties of sodium hypochlorite, it could be an alternative disinfectant solution to be used for decontamination of EBOV on sensitive apparatus. PMID:27399759

  7. Effectiveness of Four Disinfectants against Ebola Virus on Different Materials.

    PubMed

    Smither, Sophie; Phelps, Amanda; Eastaugh, Lin; Ngugi, Sarah; O'Brien, Lyn; Dutch, Andrew; Lever, Mark Stephen

    2016-01-01

    The West Africa Ebola virus (EBOV) outbreak has highlighted the need for effective disinfectants capable of reducing viral load in a range of sample types, equipment and settings. Although chlorine-based products are widely used, they can also be damaging to equipment or apparatus that needs continuous use such as aircraft use for transportation of infected people. Two aircraft cleaning solutions were assessed alongside two common laboratory disinfectants in a contact kill assay with EBOV on two aircraft relevant materials representative of a porous and non-porous surface. A decimal log reduction of viral titre of 4 is required for a disinfectant to be deemed effective and two of the disinfectants fulfilled this criteria under the conditions tested. One product, Ardrox 6092, was found to perform similarly to sodium hypochlorite, but as it does not have the corrosive properties of sodium hypochlorite, it could be an alternative disinfectant solution to be used for decontamination of EBOV on sensitive apparatus. PMID:27399759

  8. Zonal management of multi-purposes groundwater utilization based on water quality and impact on the aquifer.

    PubMed

    Liang, Ching-Ping; Jang, Cheng-Shin; Chen, Ching-Fang; Chen, Jui-Sheng

    2016-07-01

    Groundwater is widely used for drinking, irrigation, and aquaculture in the Pingtung Plain, Southwestern Taiwan. The overexploitation and poor quality of groundwater in some areas of the Pingtung Plain pose great challenges for the safe use and sustainable management of groundwater resources. Thus, establishing an effective management plan for multi-purpose groundwater utilization in the Pingtung Plain is imperative. Considerations of the quality of the groundwater and potential impact on the aquifer of groundwater exploitation are paramount to multi-purpose groundwater utilization management. This study proposes a zonal management plan for the multi-purpose use of groundwater in the Pingtung Plain. The zonal management plan is developed by considering the spatial variability of the groundwater quality and the impact on the aquifer, which is defined as the ratio of the actual groundwater extraction rate to transmissivity. A geostatistical Kriging approach is used to spatially delineate the safe zones based on the water quality standards applied in the three groundwater utilization sectors. Suitable zones for the impact on the aquifer are then spatially determined. The evaluation results showing the safe water quality zones for the three types of utilization demands and suitable zones for the impact on aquifer are integrated to create a zonal management map for multi-purpose groundwater utilization which can help government administrators to establish a water resource management strategy for safe and sustainable use of groundwater to meet multi-purpose groundwater utilization requirements in the Pingtung Plain. PMID:27343131

  9. Environmental cleaning and disinfection.

    PubMed

    Traverse, Michelle; Aceto, Helen

    2015-03-01

    The guidelines in this article provide veterinarians, veterinary technicians, and veterinary health care workers with an overview of evidence-based recommendations for the best practices associated with environmental cleaning and disinfection of a veterinary clinic that deals with small animals. Hospital-associated infections and the control and prevention programs necessary to alleviate them are addressed from an environmental perspective. Measures of hospital cleaning and disinfection include understanding mechanisms and types of contamination in veterinary settings, recognizing areas of potential concern, addressing appropriate decontamination techniques and selection of disinfectants, the management of potentially contaminated equipment, laundry, and waste management, and environmental surveillance strategies. PMID:25555560

  10. Humidifier disinfectants, unfinished stories.

    PubMed

    Choi, Yeyong; Paek, Domyung

    2016-01-01

    Once released into the air, humidifier disinfectants became tiny nano-size particles, and resulted in chemical bronchoalveolitis. Families had lost their most beloved members, and even some of them became broken. Based on an estimate of two million potential victims who had experienced adverse effects from the use of humidifier disinfectants, we can say that what we have observed was only the tip of the iceberg. Problems of entire airways, as well as other systemic effects, should be examined, as we know these nano-size particles can irritate cell membranes and migrate into systemic circulation. The story of humidifier disinfectant is not finished yet. PMID:26987713

  11. Humidifier disinfectants, unfinished stories

    PubMed Central

    Choi, Yeyong

    2016-01-01

    Once released into the air, humidifier disinfectants became tiny nano-size particles, and resulted in chemical bronchoalveolitis. Families had lost their most beloved members, and even some of them became broken. Based on an estimate of two million potential victims who had experienced adverse effects from the use of humidifier disinfectants, we can say that what we have observed was only the tip of the iceberg. Problems of entire airways, as well as other systemic effects, should be examined, as we know these nano-size particles can irritate cell membranes and migrate into systemic circulation. The story of humidifier disinfectant is not finished yet. PMID:26987713

  12. A Design and Development of Multi-Purpose CCD Camera System with Thermoelectric Cooling: Software

    NASA Astrophysics Data System (ADS)

    Oh, S. H.; Kang, Y. W.; Byun, Y. I.

    2007-12-01

    We present a software which we developed for the multi-purpose CCD camera. This software can be used on the all 3 types of CCD - KAF-0401E (768×512), KAF-1602E (15367times;1024), KAF-3200E (2184×1472) made in KODAK Co.. For the efficient CCD camera control, the software is operated with two independent processes of the CCD control program and the temperature/shutter operation program. This software is designed to fully automatic operation as well as manually operation under LINUX system, and is controled by LINUX user signal procedure. We plan to use this software for all sky survey system and also night sky monitoring and sky observation. As our results, the read-out time of each CCD are about 15sec, 64sec, 134sec for KAF-0401E, KAF-1602E, KAF-3200E., because these time are limited by the data transmission speed of parallel port. For larger format CCD, the data transmission is required more high speed. we are considering this control software to one using USB port for high speed data transmission.

  13. Evaluation of Life Sciences Glovebox (LSG) and Multi-Purpose Crew Restraint Concepts

    NASA Technical Reports Server (NTRS)

    Whitmore, Mihriban

    2005-01-01

    Within the scope of the Multi-purpose Crew Restraints for Long Duration Spaceflights project, funded by Code U, it was proposed to conduct a series of evaluations on the ground and on the KC-135 to investigate the human factors issues concerning confined/unique workstations, such as the design of crew restraints. The usability of multiple crew restraints was evaluated for use with the Life Sciences Glovebox (LSG) and for performing general purpose tasks. The purpose of the KC-135 microgravity evaluation was to: (1) to investigate the usability and effectiveness of the concepts developed, (2) to gather recommendations for further development of the concepts, and (3) to verify the validity of the existing requirements. Some designs had already been tested during a March KC-135 evaluation, and testing revealed the need for modifications/enhancements. This flight was designed to test the new iterations, as well as some new concepts. This flight also involved higher fidelity tasks in the LSG, and the addition of load cells on the gloveports.

  14. Software-programmable continuous-flow multi-purpose lab-on-a-chip.

    PubMed

    Amin, Ahmed M; Thakur, Raviraj; Madren, Seth; Chuang, Han-Sheng; Thottethodi, Mithuna; Vijaykumar, T N; Wereley, Steven T; Jacobson, Stephen C

    2013-11-01

    Current lab-on-a-chip (LoC) devices are assay-specific and are custom-built for each single experiment. Performing an experiment requires scientists or engineers to go through the time-consuming process of designing, fabricating, and testing a chip before conducting the actual experiment. This prolonged cycle can take months to complete, increasing effort and cost and reducing productivity. Similarly, minor modifications to an assay protocol re-incur the overheads of the design cycle. In this paper, we develop a multi-purpose, software-programmableLab-on-a-Chip (SPLoC), where the user simply writes or downloads a program for each experiment. We describe the components necessary to realize the SPLoC, which include a high-level programming language, an abstract instruction set, a runtime and control system, and a microfluidic device. We describe two key features of our high-level language compiler, and describe a novel variable-volume variable-ratio mixer. Finally, we demonstrate our SPLoC on four diverse, real-world assays. PMID:24436691

  15. A multi-purpose open-source triggering platform for magnetic resonance

    NASA Astrophysics Data System (ADS)

    Ruytenberg, T.; Webb, A. G.; Beenakker, J. W. M.

    2014-10-01

    Many MR scans need to be synchronised with external events such as the cardiac or respiratory cycles. For common physiological functions commercial trigger equipment exists, but for more experimental inputs these are not available. This paper describes the design of a multi-purpose open-source trigger platform for MR systems. The heart of the system is an open-source Arduino Due microcontroller. This microcontroller samples an analogue input and digitally processes these data to determine the trigger. The output of the microcontroller is programmed to mimic a physiological signal which is fed into the electrocardiogram (ECG) or pulse oximeter port of MR scanner. The microcontroller is connected to a Bluetooth dongle that allows wireless monitoring and control outside the scanner room. This device can be programmed to generate a trigger based on various types of input. As one example, this paper describes how it can be used as an acoustic cardiac triggering unit. For this, a plastic stethoscope is connected to a microphone which is used as an input for the system. This test setup was used to acquire retrospectively-triggered cardiac scans in ten volunteers. Analysis showed that this platform produces a reliable trigger (>99% triggers are correct) with a small average 8 ms variation between the exact trigger points.

  16. INITIAL WASTE PACKAGE PROBABILISTIC CRITICALITY ANALYSIS: MULTI-PURPOSE CANISTER WITH DISPOSAL CONTAINER (TBV)

    SciTech Connect

    J.R. Massari

    1995-10-06

    This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) to provide an assessment of the present waste package design from a criticality risk standpoint. The specific objectives of this initial analysis are to: (1) Establish a process for determining the probability of waste package criticality as a function of time (in terms of a cumulative distribution function, probability distribution function, or expected number of criticalities in a specified time interval) for various waste package concepts; (2) Demonstrate the established process by estimating the probability of criticality as a function of time since emplacement for an intact multi-purpose canister waste package (MPC-WP) configuration; (3) Identify the dominant sequences leading to waste package criticality for subsequent detailed analysis. The purpose of this analysis is to document and demonstrate the developed process as it has been applied to the MPC-WP. This revision is performed to correct deficiencies in the previous revision and provide further detail on the calculations performed. This analysis is similar to that performed for the uncanistered fuel waste package (UCF-WP, B00000000-01717-2200-00079).

  17. NASA and ESA Partnership on the Multi-Purpose Crew Vehicle Service Module

    NASA Technical Reports Server (NTRS)

    Schubert, Kathleen E.; Grantier, Julie A.

    2012-01-01

    (1) ESA decided in its Council Meeting in March 2011 to partially offset the European ISS obligations after 2015 with different means than ATVs; (2) The envisioned approach is based on a barter element(s) that would generate cost avoidance on the NASA side; (3) NASA and ESA considered a number of Barter options, NASA concluded that the provision by ESA of the Service Module for the NASA Multi-Purpose Crew Vehicle (MPCV) was the barter with the most interest;. (4) A joint ESA - NASA working group was established in May 2011 to assess the feasibility of Europe developing this Module based on ATV heritage; (5)The working group was supported by European and US industry namely Astrium, TAS-I and Lockheed-Martin; and (6) The project is currently in phase B1 with the objective to prepare a technical and programmatic proposal for an ESA MPCV-SM development. This proposal will be one element of the package that ESA plans submit to go forward for approval by European Ministers in November 2012.

  18. MYRRHA a multi-purpose hybrid research reactor for high-tech applications

    SciTech Connect

    Abderrahim, H. A.; Baeten, P.

    2012-07-01

    MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is the flexible experimental accelerator driven system (ADS) in development at SCK-CEN. MYRRHA is able to work both in subcritical (ADS) as in critical mode. In this way, MYRRHA will allow fuel developments for innovative reactor systems, material developments for generation IV (GEN IV) systems, material developments for fusion reactors, radioisotope production and industrial applications, such as Si-doping. MYRRHA will also demonstrate the ADS full concept by coupling the three components (accelerator, spallation target and subcritical reactor) at reasonable power level to allow operation feedback, scalable to an industrial demonstrator and allow the study of efficient transmutation of high-level nuclear waste. MYRRHA is based on the heavy liquid metal technology and so it will contribute to the development of lead fast reactor (LFR) technology and in critical mode, MYRRHA will play the role of European technology pilot plant in the roadmap for LFR. In this paper the historical evolution of MYRRHA and the rationale behind the design choices is presented and the latest configuration of the reactor core and primary system is described. (authors)

  19. WND-CHARM: Multi-purpose image classification using compound image transforms

    PubMed Central

    Orlov, Nikita; Shamir, Lior; Macura, Tomasz; Johnston, Josiah; Eckley, D. Mark; Goldberg, Ilya G.

    2008-01-01

    We describe a multi-purpose image classifier that can be applied to a wide variety of image classification tasks without modifications or fine-tuning, and yet provide classification accuracy comparable to state-of-the-art task-specific image classifiers. The proposed image classifier first extracts a large set of 1025 image features including polynomial decompositions, high contrast features, pixel statistics, and textures. These features are computed on the raw image, transforms of the image, and transforms of transforms of the image. The feature values are then used to classify test images into a set of pre-defined image classes. This classifier was tested on several different problems including biological image classification and face recognition. Although we cannot make a claim of universality, our experimental results show that this classifier performs as well or better than classifiers developed specifically for these image classification tasks. Our classifier’s high performance on a variety of classification problems is attributed to (i) a large set of features extracted from images; and (ii) an effective feature selection and weighting algorithm sensitive to specific image classification problems. The algorithms are available for free download from openmicroscopy.org. PMID:18958301

  20. Honeycomblike large area LaB6 plasma source for Multi-Purpose Plasma facility.

    PubMed

    Woo, Hyun-Jong; Chung, Kyu-Sun; You, Hyun-Jong; Lee, Myoung-Jae; Lho, Taihyeop; Choh, Kwon Kook; Yoon, Jung-Sik; Jung, Yong Ho; Lee, Bongju; Yoo, Suk Jae; Kwon, Myeon

    2007-10-01

    A Multi-Purpose Plasma (MP(2)) facility has been renovated from Hanbit mirror device [Kwon et al., Nucl. Fusion 43, 686 (2003)] by adopting the same philosophy of diversified plasma simulator (DiPS) [Chung et al., Contrib. Plasma Phys. 46, 354 (2006)] by installing two plasma sources: LaB(6) (dc) and helicon (rf) plasma sources; and making three distinct simulators: divertor plasma simulator, space propulsion simulator, and astrophysics simulator. During the first renovation stage, a honeycomblike large area LaB(6) (HLA-LaB(6)) cathode was developed for the divertor plasma simulator to improve the resistance against the thermal shock fragility for large and high density plasma generation. A HLA-LaB(6) cathode is composed of the one inner cathode with 4 in. diameter and the six outer cathodes with 2 in. diameter along with separate graphite heaters. The first plasma is generated with Ar gas and its properties are measured by the electric probes with various discharge currents and magnetic field configurations. Plasma density at the middle of central cell reaches up to 2.6 x 10(12) cm(-3), while the electron temperature remains around 3-3.5 eV at the low discharge current of less than 45 A, and the magnetic field intensity of 870 G. Unique features of electric property of heaters, plasma density profiles, is explained comparing with those of single LaB(6) cathode with 4 in. diameter in DiPS. PMID:17979417

  1. A multi-purpose open-source triggering platform for magnetic resonance.

    PubMed

    Ruytenberg, T; Webb, A G; Beenakker, J W M

    2014-10-01

    Many MR scans need to be synchronised with external events such as the cardiac or respiratory cycles. For common physiological functions commercial trigger equipment exists, but for more experimental inputs these are not available. This paper describes the design of a multi-purpose open-source trigger platform for MR systems. The heart of the system is an open-source Arduino Due microcontroller. This microcontroller samples an analogue input and digitally processes these data to determine the trigger. The output of the microcontroller is programmed to mimic a physiological signal which is fed into the electrocardiogram (ECG) or pulse oximeter port of MR scanner. The microcontroller is connected to a Bluetooth dongle that allows wireless monitoring and control outside the scanner room. This device can be programmed to generate a trigger based on various types of input. As one example, this paper describes how it can be used as an acoustic cardiac triggering unit. For this, a plastic stethoscope is connected to a microphone which is used as an input for the system. This test setup was used to acquire retrospectively-triggered cardiac scans in ten volunteers. Analysis showed that this platform produces a reliable trigger (>99% triggers are correct) with a small average 8 ms variation between the exact trigger points. PMID:25222861

  2. A case study: Transforming a vaudeville theatre into a 21st century multi-purpose hall

    NASA Astrophysics Data System (ADS)

    Talaske, Richard H.; Hoffman, Ian B.; Laney, Jonathan P.

    2002-05-01

    Originally constructed in 1927 as an atmospheric, vaudeville theatre, the Coronado enjoyed 50 years as host to a true variety of events. In the 1970s, functional and space limitations became a catalyst for touring events to avoid the Coronado, and the theatre fell into disrepair. In the mid-1990s, a renovation was planned (completed January 2001) to restore the glory of the original theatre and upgrade it to be a viable multi-purpose hall for the 21st century. By annexing two neighboring buildings, many of the space limitations could be overcome in both the front- and back-of-house. The scope included a significantly enlarged stage and stagehouse, performer support spaces, expanded lobby spaces, quiet ventilation systems, and a new music rehearsal room. Acoustically, a primary goal was to upgrade the hall for both reinforced music/theatre performances and unreinforced, orchestral performances. However, historical regulations prevented modification to the room shape and configuration. In order to make the room suitable for unreinforced music, two primary acoustic features were instituted-a semi-custom concert enclosure for the stage and an acoustic enhancement system for the audience chamber. For theatrical and popular music events, a new performance audio system was designed and integrated into the hall.

  3. Honeycomblike large area LaB6 plasma source for Multi-Purpose Plasma facility

    NASA Astrophysics Data System (ADS)

    Woo, Hyun-Jong; Chung, Kyu-Sun; You, Hyun-Jong; Lee, Myoung-Jae; Lho, Taihyeop; Choh, Kwon Kook; Yoon, Jung-Sik; Jung, Yong Ho; Lee, Bongju; Yoo, Suk Jae; Kwon, Myeon

    2007-10-01

    A Multi-Purpose Plasma (MP2) facility has been renovated from Hanbit mirror device [Kwon et al., Nucl. Fusion 43, 686 (2003)] by adopting the same philosophy of diversified plasma simulator (DiPS) [Chung et al., Contrib. Plasma Phys. 46, 354 (2006)] by installing two plasma sources: LaB6 (dc) and helicon (rf) plasma sources; and making three distinct simulators: divertor plasma simulator, space propulsion simulator, and astrophysics simulator. During the first renovation stage, a honeycomblike large area LaB6 (HLA-LaB6) cathode was developed for the divertor plasma simulator to improve the resistance against the thermal shock fragility for large and high density plasma generation. A HLA-LaB6 cathode is composed of the one inner cathode with 4in. diameter and the six outer cathodes with 2in. diameter along with separate graphite heaters. The first plasma is generated with Ar gas and its properties are measured by the electric probes with various discharge currents and magnetic field configurations. Plasma density at the middle of central cell reaches up to 2.6×1012 cm-3, while the electron temperature remains around 3-3.5eV at the low discharge current of less than 45A, and the magnetic field intensity of 870G. Unique features of electric property of heaters, plasma density profiles, is explained comparing with those of single LaB6 cathode with 4in. diameter in DiPS.

  4. Forward Bay Cover Separation Modeling and Testing for the Orion Multi-Purpose Crew Vehicle

    NASA Technical Reports Server (NTRS)

    Ali, Yasmin; Radke, Tara; Chuhta, Jesse; Hughes, Michael

    2014-01-01

    Spacecraft multi-body separation events during atmospheric descent require complex testing and analysis to validate the flight separation dynamics model and to verify no recontact. NASA Orion Multi-Purpose Crew Vehicle (MPCV) teams examined key model parameters and risk areas to develop a robust but affordable test campaign in order to validate and verify the Forward Bay Cover (FBC) separation event for Exploration Flight Test-1 (EFT-1). The FBC jettison simulation model is highly complex, consisting of dozens of parameters varied simultaneously, with numerous multi-parameter interactions (coupling and feedback) among the various model elements, and encompassing distinct near-field, mid-field, and far-field regimes. The test campaign was composed of component-level testing (for example gas-piston thrusters and parachute mortars), ground FBC jettison tests, and FBC jettison air-drop tests that were accomplished by a highly multi-disciplinary team. Three ground jettison tests isolated the testing of mechanisms and structures to anchor the simulation models excluding aerodynamic effects. Subsequently, two air-drop tests added aerodynamic and parachute parameters, and served as integrated system demonstrations, which had been preliminarily explored during the Orion Pad Abort-1 (PA-1) flight test in May 2010. Both ground and drop tests provided extensive data to validate analytical models and to verify the FBC jettison event for EFT-1, but more testing is required to support human certification, for which NASA and Lockheed Martin are applying knowledge from Apollo and EFT-1 testing and modeling to develop a robust but affordable human spacecraft capability.

  5. Forward Bay Cover Separation Modeling and Testing for the Orion Multi-Purpose Crew Vehicle

    NASA Technical Reports Server (NTRS)

    Ali, Yasmin; Chuhta, Jesse D.; Hughes, Michael P.; Radke, Tara S.

    2015-01-01

    Spacecraft multi-body separation events during atmospheric descent require complex testing and analysis to validate the flight separation dynamics models used to verify no re-contact. The NASA Orion Multi-Purpose Crew Vehicle (MPCV) architecture includes a highly-integrated Forward Bay Cover (FBC) jettison assembly design that combines parachutes and piston thrusters to separate the FBC from the Crew Module (CM) and avoid re-contact. A multi-disciplinary team across numerous organizations examined key model parameters and risk areas to develop a robust but affordable test campaign in order to validate and verify the FBC separation event for Exploration Flight Test-1 (EFT-1). The FBC jettison simulation model is highly complex, consisting of dozens of parameters varied simultaneously, with numerous multi-parameter interactions (coupling and feedback) among the various model elements, and encompassing distinct near-field, mid-field, and far-field regimes. The test campaign was composed of component-level testing (for example gas-piston thrusters and parachute mortars), ground FBC jettison tests, and FBC jettison air-drop tests that were accomplished by a highly multi-disciplinary team. Three ground jettison tests isolated the testing of mechanisms and structures to anchor the simulation models excluding aerodynamic effects. Subsequently, two air-drop tests added aerodynamic and parachute elements, and served as integrated system demonstrations, which had been preliminarily explored during the Orion Pad Abort-1 (PA-1) flight test in May 2010. Both ground and drop tests provided extensive data to validate analytical models and to verify the FBC jettison event for EFT-1. Additional testing will be required to support human certification of this separation event, for which NASA and Lockheed Martin are applying knowledge from Apollo and EFT-1 testing and modeling to develop a robust human-rated FBC separation event.

  6. HyBIS - a low cost, multi-purpose, modular vehicle for detailed ocean mapping

    NASA Astrophysics Data System (ADS)

    Huehnerbach, V.; Murton, B.; Berndt, C.; Garrard, J.; Wollatz-Vogt, M.; Wetzel, G.; Matthiessen, T.

    2013-12-01

    HyBIS is a low-cost, multi-purpose, highly maneuverable, fibre-optic controlled survey and sampling robotic underwater vehicle (RUV) capable of diving to 6000m. Built in the UK by Hydro-Lek Ltd. in collaboration with the National Oceanography Centre, Southampton, it has proven itself during recent discoveries of the deepest hydrothermal vents in the world, at 5100m deep in the Cayman Trough in the Caribbean and habitat mapping of seamounts in the Atlantic and Indian oceans . The vehicle has a modular design, with the top module being a command and power system that comprises power management, cameras, lights, hydraulics, thrusters and telemetry. The lower module can alternatively be a clam-shell sampling grab, a manipulator-arm and tool sled, a winch for instrument recovery, or an ocean bottom seismometer deployment module. Unlike a conventional ROV, HyBIS does not have any floatation, rather it is suspended by its umbilical cable directly from the ship. The advantage of direct suspension is that HyBIS can recover or deploy a payload of up to 700kg, although this comes at the price of reduced maneuverability compared to a 'normal' ROV. During its four years of service, HyBIS has, so far, accumulated an impressive list of achievements: recording over 450 hours of HD video footage, thousands of HD still images, collected geological, biological samples, as well as fluids and gas from over 40 different sites. It has also recovered two different seabed landers containing scientific equipment worth over £300k, and placed Ocean Bottom Seismometers onto the seafloor.

  7. 16 CFR 1145.17 - Multi-purpose lighters that can be operated by children; risks of death or injury.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS REGULATION OF PRODUCTS SUBJECT TO OTHER ACTS UNDER THE CONSUMER PRODUCT SAFETY ACT § 1145.17 Multi-purpose lighters that can be operated by children... the Consumer Product Safety Act any risks of injury associated with the fact that...

  8. 16 CFR 1145.17 - Multi-purpose lighters that can be operated by children; risks of death or injury.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS REGULATION OF PRODUCTS SUBJECT TO OTHER ACTS UNDER THE CONSUMER PRODUCT SAFETY ACT § 1145.17 Multi-purpose lighters that can be operated by children... the Consumer Product Safety Act any risks of injury associated with the fact that...

  9. 16 CFR 1145.17 - Multi-purpose lighters that can be operated by children; risks of death or injury.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS REGULATION OF PRODUCTS SUBJECT TO OTHER ACTS UNDER THE CONSUMER PRODUCT SAFETY ACT § 1145.17 Multi-purpose lighters that can be operated by children... the Consumer Product Safety Act any risks of injury associated with the fact that...

  10. 78 FR 13755 - Notice of Receipt of Petition for Decision That Nonconforming 2003 Jeep Wrangler Multi-Purpose...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-28

    ...This document announces receipt by the National Highway Traffic Safety Administration (NHTSA) of a petition for a decision that 2003 Jeep Wrangler multi-purpose passenger vehicles manufactured for sale in the Mexican market that were not originally manufactured to comply with all applicable Federal Motor Vehicle Safety Standards (FMVSS), are eligible for importation into the United States......

  11. The effect of a range of disinfectants on the dimensional accuracy of some impression materials.

    PubMed

    Jagger, D C; Al Jabra, O; Harrison, A; Vowles, R W; McNally, L

    2004-12-01

    In this study the dimensional accuracy of two model materials; dental stone and plaster of Paris, reproduced from three commonly used impression materials; alginate, polyether and addition-cured silicone, retained by their adhesives in acrylic resin trays and exposed to four disinfectant solutions was evaluated. Ninety casts were used to investigate the effect of the four disinfectants on the dimensional accuracy of alginate, polyether and addition-cured silicone impression material. For each impression material 30 impressions were taken, half were poured in dental stone and half in plaster of Paris. The disinfectants used were Dimenol, Perform-ID, MD-520, and Haz-tabs. Measurements were carried out using a High Precision Reflex Microscope. For the alginate impressions only those disinfected by 5-minute immersion in Haz-tabs solution and in full-strength MD 520 were not adversely affected by the disinfection treatment. All polyether impressions subjected to immersion disinfection exhibited a clinically acceptable expansion. Disinfected addition-cured silicone impressions produced very accurate stone casts. Those disinfected by spraying with fill-strength Dimenol produced casts that were very similar to those left as controls, but those treated by immersion disinfection exhibited negligible and clinically acceptable expansion. The results of the studied demonstrated that the various disinfection treatments had different effects on the impression materials. It is important that an appropriate disinfectant is used for each type of impression material. PMID:15691188

  12. A Multi-Purpose Data Dissemination Infrastructure for the Marine-Earth Observations

    NASA Astrophysics Data System (ADS)

    Hanafusa, Y.; Saito, H.; Kayo, M.; Suzuki, H.

    2015-12-01

    To open the data from a variety of observations, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) has developed a multi-purpose data dissemination infrastructure. Although many observations have been made in the earth science, all the data are not opened completely. We think data centers may provide researchers with a universal data dissemination service which can handle various kinds of observation data with little effort. For this purpose JAMSTEC Data Management Office has developed the "Information Catalog Infrastructure System (Catalog System)". This is a kind of catalog management system which can create, renew and delete catalogs (= databases) and has following features, - The Catalog System does not depend on data types or granularity of data records. - By registering a new metadata schema to the system, a new database can be created on the same system without sytem modification. - As web pages are defined by the cascading style sheets, databases have different look and feel, and operability. - The Catalog System provides databases with basic search tools; search by text, selection from a category tree, and selection from a time line chart. - For domestic users it creates the Japanese and English pages at the same time and has dictionary to control terminology and proper noun. As of August 2015 JAMSTEC operates 7 databases on the Catalog System. We expect to transfer existing databases to this system, or create new databases on it. In comparison with a dedicated database developed for the specific dataset, the Catalog System is suitable for the dissemination of small datasets, with minimum cost. Metadata held in the catalogs may be transfered to other metadata schema to exchange global databases or portals. Examples: JAMSTEC Data Catalog: http://www.godac.jamstec.go.jp/catalog/data_catalog/metadataList?lang=enJAMSTEC Document Catalog: http://www.godac.jamstec.go.jp/catalog/doc_catalog/metadataList?lang=en&tab=categoryResearch Information

  13. Friction Stir Weld Application and Tooling Design for the Multi-purpose Crew Vehicle Stage Adapter

    NASA Technical Reports Server (NTRS)

    Alcorn, John

    2013-01-01

    The Multi-Purpose Crew Vehicle (MPCV), commonly known as the Orion capsule, is planned to be the United States' next manned spacecraft for missions beyond low earth orbit. Following the cancellation of the Constellation program and creation of SLS (Space Launch System), the need arose for the MPCV to utilize the Delta IV Heavy rocket for a test launch scheduled for 2014 instead of the previously planned Ares I rocket. As a result, an adapter (MSA) must be used in conjunction with the MPCV to account for the variation in diameter of the launch vehicles; 5.5 meters down to 5.0 meters. Prior to ight article fabrication, a path nder (test article) will be fabricated to ne tune the associated manufacturing processes. The adapter will be comprised of an aluminum frustum (partial cone) that employs isogrid technology and circumferential rings on each end. The frustum will be fabricated by friction stir welding (FSW) three individual panels together on a Vertical Weld Tool (VWT) at NASA Marshall Space Flight Center. Subsequently, each circumferential ring will be friction stir welded to the frustum using a Robotic Weld Tool (RWT). The irregular geometry and large mass of the MSA require that extensive tooling preparation be put into support structures for the friction stir weld. The tooling on the VWT will be comprised of a set of conveyors mounted on pre-existing stanchions so that the MSA will have the ability to be rotated after each of the three friction stir welds. The tooling requirements to friction stir weld the rings with the RWT are somewhat more demanding. To support the mass of the MSA and resist the load of the weld tool, a system of mandrels will be mounted to stanchions and assembled in a circle. The goal of the paper will be to explain the design, fabrication, and assembly of the tooling, to explain the use of friction stir welding on the MSA path nder, and also to discuss the lessons learned and modi cations made in preparation for ight article fabrication

  14. NASA Planning for Orion Multi-Purpose Crew Vehicle Ground Operations

    NASA Technical Reports Server (NTRS)

    Letchworth, Gary; Schlierf, Roland

    2011-01-01

    tools included Kaizen/Lean events, mockups and human factors analysis. The majority of products developed by this team are applicable as KSC prepares 21st Century Ground Systems for the Orion Multi-Purpose Crew Vehicle and Space Launch System.

  15. Microbial contamination and disinfection methods of pacifiers

    PubMed Central

    NELSON, Paulo; LOUVAIN, Márcia Costa; MACARI, Soraia; LUCISANO, Marília Pacífico; da SILVA, Raquel Assed Bezerra; de QUEIROZ, Alexandra Mussolino; GATON-HERNÁNDEZ, Patrícia; da SILVA, Léa Assed Bezerra

    2015-01-01

    Objectives To evaluate the microbial contamination of pacifiers by Mutans Streptococci (MS) and the efficacy of different methods for their disinfection. Methods Twenty-eight children were assigned to a 4-stage changeover system with a 1-week interval. In each stage, children received a new pacifier and the parents were instructed to maintain their normal habits for 1 week. After this time, the pacifiers were subjected to the following 4 disinfection methods: spraying with 0.12% chlorhexidine solution, Brushtox® or sterile tap water, and immersion in boiling tap water for 15 minutes. Microbiological culture for MS and Scanning Electron Microscopy (SEM) were performed. The results were analyzed statistically by Friedman’s non-parametric test (a=0.05). Results The 0.12% chlorhexidine spray was statistically similar to the boiling water (p>0.05) and more effective than the Brushtox® spray and control (p<0.05). The analysis of SEM showed the formation of a cariogenic biofilm in all groups with positive culture. Conclusions Pacifiers become contaminated by MS after their use by children and should be disinfected routinely. Spraying with a 0.12% chlorhexidine solution and immersion in boiling water promoted better disinfection of the pacifiers compared with a commercial antiseptic toothbrush cleanser (Brushtox®). PMID:26537723

  16. DISINFECTION OF NEW WATER MAINS

    EPA Science Inventory

    The 'AWWA Standard for Disinfecting Water Mains' (AWWA C601-68) has fallen into disuse by a number of water utilities because of repeated bacteriological failures following initial disinfection with the recommended high-dose chlorination. Other methods of disinfection, including ...

  17. Routine disinfection of the total dialysis fluid system.

    PubMed

    Gorke, A; Kittel, J

    2002-01-01

    The importance of bacteria and endotoxin free, sterile dialysis fluid for long term, high quality haemodialysis treatment is obvious and very much demanded (1,2). Dead spaces and connections between units (segments) of fluid production and delivery in elder systems are a continuous source for bacteria growth, biofilm generation and endotoxin release (3). After varying success with routine disinfection of system components showing partly fast recovery and growth of bacteria (i.e. < 48 hours) we changed to routine disinfection of the entire fluid production and distribution system. We call this'system disinfection'. We report the methods and results from observation of practice over 28 months of disinfection. The fluid system is composed of a soft water tank, reverse osmosis (double RO), RO fluid loop, central bicarbonate production and delivery system and dialysis stations with and without ultrafilter and citric-thermal disinfection before and after each haemodialysis. The system disinfection is carried out bimonthly with peracetic acid 3.5% in > 0.1% solution at a mean temperature of > 15 degrees C and at a minimum of 60 minutes of disinfection time. Samples for microbiological testing and endotoxin measurement were assessed 3-4 monthly at 7 measurement points. The tests were carried out 7 times on the 11th day (mean value [MV]) after routine system disinfection. The result was in 0.2 CFU/ml (MV) in 40 tests. The endotoxin levels (IU/L) were all < 0.25 except one at 0.325 in RO water. Endotoxin was assessed 5 times in 26 tests over 28 months. Samples were taken at 10.5 (MV) days after system disinfection. The Gel Clot or turbometric method was used. Efficient and preventive routine system disinfection of an entire dialysis fluid production and distribution system as standard in modern equipment - can support sufficient quality in dialysis fluid produced and distributed by elder and composed systems. PMID:12371736

  18. Recent advances in drinking water disinfection: successes and challenges.

    PubMed

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    , it is recommended that water disinfection should never be compromised by attempting to control DBPs. The reason for this is that the risks of human illness and death from pathogens in drinking water are much greater than the risks from exposure to disinfectants and disinfection by-products. Nevertheless, if DBP levels exceed regulatory limits, strategies should focus on eliminating organic impurities that foster their formation, without compromising disinfection. As alternatives to chlorine, disinfectants such as chloramines, ozone, chlorine dioxide, and UV disinfection are gaining popularity. Chlorine and each of these disinfectants have individual advantage and disadvantage in terms of cost, efficacy-stability, ease of application, and nature of disinfectant by-products (DBPs). Based on efficiency, ozone is the most efficient disinfectant for inactivating bacteria, viruses, and protozoa. In contrast, chloramines are the least efficient and are not recommended for use as primary disinfectants. Chloramines are favored for secondary water disinfection, because they react more slowly than chlorine and are more persistent in distribution systems. In addition, chloramines produce lower DBP levels than does chlorine, although microbial activity in the distribution system may produce nitrate from monochloramine, when it is used as a residual disinfectant, Achieving the required levels of water quality, particularly microbial inactivation levels, while minimizing DBP formation requires the application of proper risk and disinfection management protocols. In addition, the failure of conventional treatment processes to eliminate critical waterborne pathogens in drinking water demand that improved and/or new disinfection technologies be developed. Recent research has disclosed that nanotechnology may offer solutions in this area, through the use of nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes, and nanoparticle-enhanced filtration

  19. Effective reprocessing of reusable dispensers for surface disinfection tissues – the devil is in the details

    PubMed Central

    Kampf, Günter; Degenhardt, Stina; Lackner, Sibylle; Ostermeyer, Christiane

    2014-01-01

    Background: It has recently been reported that reusable dispensers for surface disinfection tissues may be contaminated, especially with adapted Achromobacter species 3, when products based on surface-active ingredients are used. Fresh solution may quickly become recontaminated if dispensers are not processed adequately. Methods: We evaluated the abilities of six manual and three automatic processes for processing contaminated dispensers to prevent recolonisation of a freshly-prepared disinfectant solution (Mikrobac forte 0.5%). Dispensers were left at room temperature for 28 days. Samples of the disinfectant solution were taken every 7 days and assessed quantitatively for bacterial contamination. Results: All automatic procedures prevented recolonisation of the disinfectant solution when a temperature of 60–70°C was ensured for at least 5 min, with or without the addition of chemical cleaning agents. Manual procedures prevented recontamination of the disinfectant solution when rinsing with hot water or a thorough cleaning step was performed before treating all surfaces with an alcohol-based disinfectant or an oxygen-releaser. Other cleaning and disinfection procedures, including the use of an alcohol-based disinfectant, did not prevent recolonisation. Conclusions: These results indicate that not all processes are effective for processing reusable dispensers for surface-disinfectant tissues, and that a high temperature during the cleaning step or use of a biofilm-active cleaning agent are essential. PMID:24653973

  20. Wettability changes in polyether impression materials subjected to immersion disinfection

    PubMed Central

    Shetty, Shweta; Kamat, Giridhar; Shetty, Rajesh

    2013-01-01

    Background: Disinfection of impression materials prevents cross-contamination; however, the disinfectants may alter the wettability property. The purpose of this investigation was to evaluate the wettability changes of polyether impression material after immersing in four different chemical disinfectant solutions for a period of 10 min and 30 min, respectively. Materials and Methods: A total of 45 samples of polyether dental impression material (Impregum soft, 3MESPE, St. Paul, MN, USA) were randomly divided into nine groups with five specimens each. Each specimen was disc shaped, flat of 32 mm diameter and 3 mm thickness. The samples were immersed in four disinfectant solutions: 2% Glutaraldehyde, 5% sodium hypochlorite, 0.05% iodophor, and 5.25% phenol for 10 min and 30 min, respectively. The control was without disinfection. Wettability of the samples was assessed by measuring the contact angle by using the Telescopic Goniometer. Data were subjected to analysis of variance (Fisher's test) and Tukey's post hoc test for multiple comparisons at 5% level of significance. Results: The contact angle of 20.21° ± 0.22° were recorded in the control samples. After 10 min, the samples that were immersed in 5% sodium hypochlorite and 5.25% phenol showed significant statistical increase in the contact angle as compared to the control (P < 0.001). After 30 min of disinfection, only the samples immersed in 0.05% iodophor showed there were no significant changes in the contact angle, whereas the other disinfectants significantly increased the contact angle and decreased the wettability of the polyether material. Conclusion: Within the limitations of the study, 2% glutaraldehyde proved safe for 10 min of immersion disinfection while 0.05% iodophor holds promise as an effective disinfectant without affecting the wettability of the material. PMID:24130593

  1. CHLORINE DISINFECTION OF AEROMONAS

    EPA Science Inventory

    The bacterial genus Aeromonas is currently listed on the USEPA's Candidate Contaminant List (CCL). Resistance to chemical disinfection is an essential aspect regarding all microbial groups listed on the CCL. This study was designed to determine the inactivation kinetics of Aeromo...

  2. Disinfection of bedpans

    PubMed Central

    Darmady, E. M.; Hughes, K. E. A.; Jones, J. D.; Prince, D.; Verdon, Patricia

    1961-01-01

    A standard dish-washing machine fitted with an automatic cycle has been used to clean and disinfect bedpans. Visual and bacteriological examinations have shown that the machine produces superior and more reliable results than in trials of bedpans submitted to previously described methods. PMID:13719783

  3. Efficacy of a variety of disinfectants against Listeria spp.

    PubMed Central

    Best, M; Kennedy, M E; Coates, F

    1990-01-01

    The efficacy of 14 disinfectants against Listeria innocua and two strains of Listeria monocytogenes in the presence of organic matter was studied. Quantitative efficacy tests were used. Many of the disinfectants tested were not as effective on Listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). The presence of whole serum and milk (2% fat) further reduced the disinfectant capacities of most of the formulations studied. Only three disinfectants (povidone-iodine, chlorhexidine gluconate, and glutaraldehyde) were effective in the carrier test in the presence of serum; however, all three were ineffective when challenged with milk (2% fat). Only one solution, sodium dichloroisocyanurate, was effective in the presence of milk. All but four formulations (chloramine-T, phosphoric acid, an iodophor, and formaldehyde) were effective in the suspension tests, regardless of the organic load. L. monocytogenes was observed to be slightly more resistant to disinfection than L. innocua was. There was no difference in disinfectant susceptibility between the two strains of L. monocytogenes. These findings emphasize the need for caution in selecting an appropriate disinfectant for use on contaminated surfaces, particularly in the presence of organic material. PMID:2106285

  4. Efficacy of a variety of disinfectants against Listeria spp.

    PubMed

    Best, M; Kennedy, M E; Coates, F

    1990-02-01

    The efficacy of 14 disinfectants against Listeria innocua and two strains of Listeria monocytogenes in the presence of organic matter was studied. Quantitative efficacy tests were used. Many of the disinfectants tested were not as effective on Listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). The presence of whole serum and milk (2% fat) further reduced the disinfectant capacities of most of the formulations studied. Only three disinfectants (povidone-iodine, chlorhexidine gluconate, and glutaraldehyde) were effective in the carrier test in the presence of serum; however, all three were ineffective when challenged with milk (2% fat). Only one solution, sodium dichloroisocyanurate, was effective in the presence of milk. All but four formulations (chloramine-T, phosphoric acid, an iodophor, and formaldehyde) were effective in the suspension tests, regardless of the organic load. L. monocytogenes was observed to be slightly more resistant to disinfection than L. innocua was. There was no difference in disinfectant susceptibility between the two strains of L. monocytogenes. These findings emphasize the need for caution in selecting an appropriate disinfectant for use on contaminated surfaces, particularly in the presence of organic material. PMID:2106285

  5. Poorly processed reusable surface disinfection tissue dispensers may be a source of infection

    PubMed Central

    2014-01-01

    Background Reusable surface disinfectant tissue dispensers are used in hospitals in many countries because they allow immediate access to pre-soaked tissues for targeted surface decontamination. On the other hand disinfectant solutions with some active ingredients may get contaminated and cause outbreaks. We determined the frequency of contaminated surface disinfectant solutions in reusable dispensers and the ability of isolates to multiply in different formulations. Methods Reusable tissue dispensers with different surface disinfectants were randomly collected from healthcare facilities. Solutions were investigated for bacterial contamination. The efficacy of two surface disinfectants was determined in suspension tests against two isolated species directly from a contaminated solution or after 5 passages without selection pressure in triplicate. Freshly prepared use solutions were contaminated to determine survival of isolates. Results 66 dispensers containing disinfectant solutions with surface-active ingredients were collected in 15 healthcare facilities. 28 dispensers from nine healthcare facilities were contaminated with approximately 107 cells per mL of Achromobacter species 3 (9 hospitals), Achromobacter xylosoxidans or Serratia marcescens (1 hospital each). In none of the hospitals dispenser processing had been adequately performed. Isolates regained susceptibility to the disinfectants after five passages without selection pressure but were still able to multiply in different formulations from different manufacturers at room temperature within 7 days. Conclusions Neglecting adequate processing of surface disinfectant dispensers has contributed to frequent and heavy contamination of use-solutions based on surface active ingredients. Tissue dispenser processing should be taken seriously in clinical practice. PMID:24447780

  6. In vitro study on the disinfectability of two split-septum needle-free connection devices using different disinfection procedures

    PubMed Central

    Engelhart, Steffen; Exner, Martin; Simon, Arne

    2015-01-01

    This in vitro study investigated the external disinfection of two needle-free connection devices (NFC) using Octeniderm® (spraying and wiping technique) vs. Descoderm® pads (wiping technique). The split-septum membrane of the NFC was contaminated with >105 CFU K. pneumoniae or S. epidermidis. The efficacy of the disinfection at 30 sec. exposure time was controlled by taking a swab sample and by flushing the NFC with sterile 0.9% sodium chloride solution. Disinfection with octenidine dihydrochloride 0.1 g, 1-Propanol 30.0 g, and 2-Propanol 45.0 g in 100 g solution was highly effective (CFU reduction ≥4 log) against both microorganisms, whereas the use of 63.1 g 2-Propanol in 100 ml solution led to residual contamination with S. epidermidis. Our investigation underlines that (i) in clinical practice disinfection of NFCs before use is mandatory, and that (ii) details of disinfection technique are of utmost importance regarding their efficacy. Our investigation revealed no significant differences between both split-septum NFC types. Clinical studies are needed to confirm a possible superiority of disinfectants with long-lasting residual antimicrobial activity. PMID:26693394

  7. Resistance of Pseudomonas aeruginosa Isolates to Hydrogel Contact Lens Disinfection Correlates with Cytotoxic Activity

    PubMed Central

    Lakkis, Carol; Fleiszig, Suzanne M. J.

    2001-01-01

    One of the most common pathogens in infection of hydrogel contact lens wearers is Pseudomonas aeruginosa, which can gain access to the eye via contamination of the lens, lens case, and lens care solutions. Only one strain per species is used in current regulatory testing for the marketing of chemical contact lens disinfectants. The aim of this study was to determine whether P. aeruginosa strains vary in their susceptibility to hydrogel contact lens disinfectants. A method for rapidly screening bacterial susceptibility to contact lens disinfectants was developed, based on measurement of the MIC. The susceptibility of 35 P. aeruginosa isolates to two chemical disinfectants was found to vary among strains. MICs ranged from 6.25 to 100% for both disinfectants at 37°C, and a number of strains were not inhibited by a 100% disinfectant concentration in the lens case environment at room temperature (22°C). Resistance to disinfection appeared to be an inherent rather than acquired trait, since some resistant strains had been isolated prior to the introduction of the disinfectants and some susceptible P. aeruginosa strains could not be made more resistant by repeated disinfectant exposure. A number of P. aeruginosa strains which were comparatively more resistant to short-term disinfectant exposure also demonstrated the ability to grow to levels above the initial inoculum in one chemical disinfectant after long-term (24 to 48 h) disinfectant exposure. Resistance was correlated with acute cytotoxic activity toward corneal epithelial cells and with exsA, which encodes a protein that regulates cytotoxicity via a complex type III secretion system. These results suggest that chemical disinfection solutions may select for contamination with cytotoxic strains. Further investigation of the mechanisms and factors responsible for resistance may also lead to strategies for reducing adverse responses to contact lens wear. PMID:11283074

  8. Effects of disinfectants in renal dialysis patients

    SciTech Connect

    Klein, E.

    1986-11-01

    Patients receiving hemodialysis therapy risk exposure to both disinfectants and sterilants. Dialysis equipment is disinfected periodically with strong solutions of hypochlorite or formaldehyde. Gross hemolysis resulting from accidental hypochlorite infusion has led to cardiac arrest, probably as a result of hyperkalemia. Formaldehyde is commonly used in 4% solutions to sterilize the fluid paths of dialysis controllers and to sterilize dialyzers before reuse. It can react with red cell antigenic surfaces leading to the formation of anti-N antibodies. The major exposure risk is the low concentration of disinfectant found in municipal water used to prepare 450 L dialysate weekly. With thrice-weekly treatment schedules, the quality requirements for water used to make this solution must be met rigorously. Standards for water used in the preparation of dialysate have recently been proposed but not all patients are treated with dialysate meeting such standards. The introduction of sterilants via tap water is insidious and has let to more pervasive consequences. Both chlorine and chloramines, at concentrations found in potable water, are strong oxidants that cause extensive protein denaturation and hemolysis. Oxidation of the Fe/sup 2 +/ in hemoglobin to Fe/sup 3 +/ forms methemoglobin, which is incapable of carrying either O/sub 2/ or CO/sub 2/. Chloramine can form not only methemoglobin, but can also denature proteins within the red cell, thus forming aggregates (Heinz bodies). Chloramines also inhibit hexose monophosphate shunt activity, a mechanism that makes the red cell even more susceptible to oxidant damage.

  9. [Cleaning and disinfection of cattle trucks (author's transl)].

    PubMed

    Osinga, A; Dijkstra, R G

    1981-12-15

    When the Order on 'Disinfection of Motor Vehicles and Trailers, 1976' failed to fulfil its purpose in practice, the present authors made a closer examination of the bacteriological state of cattle trucks, both before cleaning as required by law and after cleaning and disinfection. The supposition that loading platforms lined with aluminum are more readily cleaned than are wooden platforms, was verified by the results. Moreover, it was found that aluminium-lined platforms can be adequately cleaned with cold water. Markedly superior results are not obtained when hot water (approximately 80 degrees C) is used. An effective disinfectant should be applied after cleaning to reduce bacteriological contamination to a further extent. When the loading platforms have been cleaned using a high-pressure syringe, satisfactory results are obtained by disinfection with a one per cent solution of Halamid or a solution of Stafilex (750 ppm of active chlorine). To ensure an effective control of disease in animals, the loading platforms of cattle trucks should be cleaned and disinfected daily after use. The above disinfectants are useful for this purpose but sodium hydroxide is unsuited because of its corrosive effect. PMID:7324022

  10. Use of Hydrogen Peroxide to Disinfect Hydroponic Plant Growth Systems

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Henderson, Keith

    2000-01-01

    Hydrogen peroxide was studied as an alternative to conventional bleach and rinsing methods to disinfect hydroponic plant growth systems. A concentration of 0.5% hydrogen peroxide was found to be effective. Residual hydrogen peroxide can be removed from the system by repeated rinsing or by flowing the solution through a platinum on aluminum catalyst. Microbial populations were reduced to near zero immediately after treatment but returned to pre-disinfection levels 2 days after treatment. Treating nutrient solution with hydrogen peroxide and planting directly into trays being watered with the nutrient solution without replenishment, was found to be detrimental to lettuce germination and growth.

  11. Managing runoff and flow pathways in a small rural catchment to reduce flood risk with other multi-purpose benefits

    NASA Astrophysics Data System (ADS)

    Wilkinson, Mark; Welton, Phil; Kerr, Peter; Quinn, Paul; Jonczyk, Jennine

    2010-05-01

    Belford only two houses were flooded. Data from the catchment and mitigation features showed that the defence measures resulted in an increase in travel time of the peak and attenuated high flows which would have usually travelled quickly down the channel to the village. For example, the pilot feature appears to have increased the travel time of a flood peak at the top of the catchment from 20 minutes to 35 minutes over a 1 km stretch of channel. There are currently ten active mitigation features present in the catchment. More features are planned for construction this year. Early data from the catchment indicates that the runoff attenuation features are having an impact on reducing flood flows in the channel and also slowing down the flood peak. At the same time the multi-purpose aspects of the features are apparent.

  12. Design and fabrication of a multi-purpose soft x-ray array diagnostic system for KSTAR.

    PubMed

    Lee, Seung Hun; Chai, Kil Byoung; Jang, Siwon; Ko, Won-Ha; Kim, Junghee; Seo, Dongcheol; Lee, Jongha; Bogatu, I N; Kim, Jin-Soo; Choe, Wonho

    2012-10-01

    A multi-purpose soft x-ray array diagnostic system was developed for measuring two-dimensional x-ray emissivity profile, electron temperature, Ar impurity transport, and total radiation power. A remotely controlled filter wheel was designed with three different choices of filters. The electron temperature profile can be determined from the ratio of two channels having different thickness of Be layer, and the Ar impurity concentration transport can be determined from a pair of Ar Ross filters (CaF(2) and NaCl thin films). Without any filters, this diagnostic system can also be used as a bolometer. PMID:23127019

  13. Design and fabrication of a multi-purpose soft x-ray array diagnostic system for KSTAR

    SciTech Connect

    Lee, Seung Hun; Chai, Kil Byoung; Jang, Siwon; Choe, Wonho; Ko, Won-Ha; Kim, Junghee; Seo, Dongcheol; Lee, Jongha; Bogatu, I. N.; Kim, Jin-Soo

    2012-10-15

    A multi-purpose soft x-ray array diagnostic system was developed for measuring two-dimensional x-ray emissivity profile, electron temperature, Ar impurity transport, and total radiation power. A remotely controlled filter wheel was designed with three different choices of filters. The electron temperature profile can be determined from the ratio of two channels having different thickness of Be layer, and the Ar impurity concentration transport can be determined from a pair of Ar Ross filters (CaF{sub 2} and NaCl thin films). Without any filters, this diagnostic system can also be used as a bolometer.

  14. Disinfection and wildlife.

    PubMed

    Corn, J L; Nettles, V F

    1995-06-01

    Capture, handling or transport of wildlife for purposes such as research, disease monitoring, wildlife damage control, relocation, and collection of zoological specimens can create risks of disease spread. Cleaning and disinfection procedures for equipment used in these activities must be routine and designed to eliminate the spread of pathogens to either animals or humans. General methods and materials for cleaning and disinfection apply to wildlife studies. Concepts involved in preparing a protocol specific to a wildlife investigation are discussed. The control of the spread of livestock and poultry pathogens via free-ranging mammals and birds prior to disinfection of contaminated premises is approached through an accurate assessment of the problem and, where necessary, the selection of appropriate wildlife control measures. The authors discuss the development of a problem assessment, and review potential methods for use in the control of wildlife. For an accurate problem assessment, information is needed on the presence of wild mammals and birds at the site, exposure of wild mammals and birds to the pathogen, and the potential for further transmission. When wildlife control is deemed necessary, techniques may be selected to disperse or exclude animals from premises or to depopulate the site. Dispersal or exclusion from premises is appropriate when movement of animals within or away from the contaminated premises would not result in further transmission of the pathogen. Depopulation is necessary when the continued presence or dispersal of wild mammals or birds would potentially result in further spread of the disease. PMID:7579643

  15. Bacterial contamination of a phenolic disinfectant.

    PubMed

    Simmons, N A; Gardner, D A

    1969-06-14

    Twenty ward stock bottles of aqueous 1% Printol were examined and 17 were found to be contaminated with Alcaligenes faecalis. Organisms were present in dead space behind the plastic liners of the bottle caps, where they could have survived washing. A. faecalis was also isolated from 31 out of 34 1% Printol solutions in use in the hospital. Pseudomonas aeruginosa was grown from two samples of 1% Printol in one ward, but not from stock bottles.The minimal bactericidal concentration (M.B.C.) in aqueous solution of Hycolin, Sudol, and Stericol for A. faecalis and Ps. aeruginosa was 1 in 320. The M.B.C. of Printol for both organisms was 1 in 80. The activity of all four disinfectants was reduced in the presence of large amounts of organic matter. Sudol was the least affected. Polyethylene, of which stock bottles were made, did not reduce the activity of the disinfectants. It is suggested that, ideally, stock bottles of disinfectant diluted ready for use should be autoclaved before they are refilled. PMID:4977328

  16. A target field design of open multi-purpose RF coil for musculoskeletal MR imaging at 3T.

    PubMed

    Gao, Fei; Zhang, Rui; Zhou, Diange; Wang, Xiaoying; Huang, Kefu; Zhang, Jue

    2016-10-01

    Musculoskeletal MR imaging under multi-angle situations plays an increasingly important role in assessing joint and muscle tissues system. However, there are still limitations due to the closed structures of most conventional RF coils. In this study, a time-harmonic target-field method was employed to design open multi-purpose coil (OMC) for multi-angle musculoskeletal MR imaging. The phantom imaging results suggested that the proposed OMC could achieve homogeneously distributed magnetic field and high signal-to-noise ratio (SNR) of 239.04±0.83 in the region of interest (ROI). The maximum temperature in the heating hazard test was 16°C lower than the standard regulation, which indicated the security of the designed OMC. Furthermore, to demonstrate the effectiveness of the proposed OMC for musculoskeletal MR imaging, especially for multi-angle imaging, a healthy volunteer was examined for MR imaging of elbow, ankle and knee using OMC. The in vivo imaging results showed that the proposed OMC is effective for MR imaging of musculoskeletal tissues at different body parts, with satisfied B1 field homogeneity and SNR. Moreover, the open structure of the OMC could provide a large joint movement region. The proposed open multi-purpose coil is feasible for musculoskeletal MR imaging, and potentially, it is more suitable for the evaluation of musculoskeletal tissues under multi-angle conditions. PMID:27114344

  17. Mechanisms of actions of sodium hypochlorite in cleaning and disinfection processes.

    PubMed

    Fukuzaki, Satoshi

    2006-12-01

    Sodium hypochlorite (NaOCl) is the most widely used disinfectant in the food industry despite the increasing availability of other disinfectants. Sodium hypochlorite fulfills many requirements as the ideal disinfectant and furthermore it has an excellent cleaning action. The effectiveness of sodium hypochlorite in the cleaning and disinfection processes depends on the concentration of available chlorine and the pH of the solution. Hypochlorous acid (HOCl) is a weak acid and dissociates to the hypochlorite ion (-OCl) and proton (H+) depending on the solution pH. It is generally believed that HOCl is the active species in the germicidal action, whereas the concentration of -OCl is a key factor determining the cleaning efficiency. This implies that the optimal pH region of the germicidal activity of sodium hypochlorite differs from that of its cleaning activity. This paper describes the theory and practice of the cleaning and disinfecting operations based on the use of sodium hypochlorite solution. PMID:17190269

  18. A multi-purpose system for water purification and sea-water softening.

    PubMed

    Barsky, L; Rubinstein, J; Barsky, S; Kirzhner, F; Bodul, O

    1998-01-01

    A novel technique that can be used for reacting toxic carbon dioxide (CO2) emissions from power plants and other combustion wastes with sea water is described. A chemical interaction between CO2 and the cations in sea water, with the pH electrolytically regulated, can precipitate almost all the calcium and magnesium ions, as well as some sodium and potassium ions, as carbonates and bicarbonates. The carbonates and bicarbonates thus prepared can then be mixed with ash to yield a building material. Sulfur ions will be neutralized with calcium and magnesium, and the remaining ions can be removed using reverse osmosis or some other method. The technology and equipment for purification are based on modules that can be used for industrial waste-water, sea water, solutions, and otherwise. The module for separation of sand and suspended coarse substances consists of a tank for flocculation, coagulation, and precipitation of solid particles; and a low-pressure hydrocyclone. The module for purification from oil and fine suspensions is based on column flotation, flotation with a special ejector, and adhesion flotation. The module for ions and colloids consists of an absorbing filter with zeolite, fly ash, and other absorbing materials. Using a laboratory model consisting of a special mini-plant, we processed 10 L of factory-waste water containing more than 20 g/L organic content (compare with the upper limit of 0.02 g/L allowed by the Ministry of Environmental Protection in Israel). After the experimental solution was treated and evaporated to a small bulk, the water obtained was almost clear. On the basis of the results in the model, we present a scaled-up process for the design, development, and production of equipment for and the assembly of a large installation for drainage and water purification. PMID:9987815

  19. Effect of well disinfection on arsenic in ground water

    USGS Publications Warehouse

    Gotkowitz, M.; Ellickson, K.; Clary, A.; Bowman, G.; Standridge, J.; Sonzogni, W.

    2008-01-01

    Domestic water wells are routinely subjected to in situ chemical disinfection treatments to control nuisance or pathogenic bacteria. Most treatments are chlorine based and presumably cause strongly oxidizing conditions in the wellbore. Water resource managers in Wisconsin were concerned that such treatments might facilitate release of arsenic from sulfide minerals disseminated within a confined sandstone aquifer. To test this hypothesis, a well was subjected to four disinfection treatments over 9 months time. The first treatment consisted of routine pumping of the well without chemical disinfection; three subsequent treatments included chlorine disinfection and pumping. Pretreatment arsenic concentrations in well water ranged from 7.4 to 18 ??g/L. Elevated arsenic concentrations up to 57 ??g/L in the chemical treatment solutions purged from the well are attributed to the disintegration or dissolution of biofilms or scale. Following each of the four treatments, arsenic concentrations decreased to less than 10 ??g/L during a period of pumping. Arsenic concentrations generally returned to pretreatment levels under stagnant, nonpumping conditions imposed following each treatment. Populations of iron-oxidizing, heterotrophic, and sulfate-reducing bacteria decreased following chemical treatments but were never fully eradicated from the well. Strongly oxidizing conditions were induced by the chlorine-based disinfections, but the treatments did not result in sustained increases in well water arsenic. Results suggest that disruption of biofilm and mineral deposits in the well and the water distribution system in tandem with chlorine disinfection can improve water quality in this setting. ?? 2008 The Author(s).

  20. Effects of Disinfectants on Larval Development of Ascaris suum Eggs.

    PubMed

    Oh, Ki-Seok; Kim, Geon-Tae; Ahn, Kyu-Sung; Shin, Sung-Shik

    2016-02-01

    The objective of this study was to evaluate the effects of several different commercial disinfectants on the embryogenic development of Ascaris suum eggs. A 1-ml aliquot of each disinfectant was mixed with approximately 40,000 decorticated or intact A. suum eggs in sterile tubes. After each treatment time (at 0.5, 1, 5, 10, 30, and 60 min), disinfectants were washed away, and egg suspensions were incubated at 25˚C in distilled water for development of larvae inside. At 3 weeks of incubation after exposure, ethanol, methanol, and chlorohexidin treatments did not affect the larval development of A. suum eggs, regardless of their concentration and treatment time. Among disinfectants tested in this study, 3% cresol, 0.2% sodium hypochlorite and 0.02% sodium hypochlorite delayed but not inactivated the embryonation of decorticated eggs at 3 weeks of incubation, because at 6 weeks of incubation, undeveloped eggs completed embryonation regardless of exposure time, except for 10% povidone iodine. When the albumin layer of A. suum eggs remained intact, however, even the 10% povidone iodine solution took at least 5 min to reasonably inactivate most eggs, but never completely kill them with even 60 min of exposure. This study demonstrated that the treatment of A. suum eggs with many commercially available disinfectants does not affect the embryonation. Although some disinfectants may delay or stop the embryonation of A. suum eggs, they can hardly kill them completely. PMID:26951988

  1. Effects of Disinfectants on Larval Development of Ascaris suum Eggs

    PubMed Central

    Oh, Ki-Seok; Kim, Geon-Tae; Ahn, Kyu-Sung; Shin, Sung-Shik

    2016-01-01

    The objective of this study was to evaluate the effects of several different commercial disinfectants on the embryogenic development of Ascaris suum eggs. A 1-ml aliquot of each disinfectant was mixed with approximately 40,000 decorticated or intact A. suum eggs in sterile tubes. After each treatment time (at 0.5, 1, 5, 10, 30, and 60 min), disinfectants were washed away, and egg suspensions were incubated at 25˚C in distilled water for development of larvae inside. At 3 weeks of incubation after exposure, ethanol, methanol, and chlorohexidin treatments did not affect the larval development of A. suum eggs, regardless of their concentration and treatment time. Among disinfectants tested in this study, 3% cresol, 0.2% sodium hypochlorite and 0.02% sodium hypochlorite delayed but not inactivated the embryonation of decorticated eggs at 3 weeks of incubation, because at 6 weeks of incubation, undeveloped eggs completed embryonation regardless of exposure time, except for 10% povidone iodine. When the albumin layer of A. suum eggs remained intact, however, even the 10% povidone iodine solution took at least 5 min to reasonably inactivate most eggs, but never completely kill them with even 60 min of exposure. This study demonstrated that the treatment of A. suum eggs with many commercially available disinfectants does not affect the embryonation. Although some disinfectants may delay or stop the embryonation of A. suum eggs, they can hardly kill them completely. PMID:26951988

  2. Surface-Dried Viruses Can Resist Glucoprotamin-Based Disinfection

    PubMed Central

    Rapp, Ingrid

    2014-01-01

    Touching of contaminated objects and surfaces is a well-known method of virus transmission. Once they are attached to the hands, viruses can easily get adsorbed and initiate infection. Hence, disinfection of frequently touched surfaces is of major importance to prevent virus spreading. Here we studied the antiviral activity of a glucoprotamin-containing disinfectant against influenza A virus and the model virus vaccinia virus (VACV) dried on inanimate surfaces. The efficacy of the surface disinfectant on stainless steel, polyvinyl chloride, and glass coupons was investigated in a quantitative carrier test. Vacuum-dried viruses were exposed to 0.25%, 0.5%, and 1% disinfectant for 5 min, 15 min, and 30 min without agitation, and residual infectivity was determined by endpoint titration. Although glucoprotamin was highly active against both viruses in suspension, limited antiviral activity against the surface-dried viruses was detected. Even after 30 min of exposure to 1% disinfectant, VACV was not completely inactivated. Furthermore, influenza A virus inactivation was strongly affected by the surface composition during the 5-min and 15-min treatments with 0.25% and 0.5% disinfectant. The results presented in this study highlight the relevance of practical tests to assess the antiviral activity of surface disinfectants. High virucidal activity in solution is not necessarily indicative of high antiviral activity against surface-dried viruses. In addition, we want to emphasize that the mere exposure of surfaces to disinfectants might not be sufficient for virus inactivation and mechanical action should be applied to bring attached viruses into contact with virucidal compounds. PMID:25217017

  3. In vitro-in vivo sequence studies as a method of selecting the most efficacious alcohol-based solution for hygienic hand disinfection.

    PubMed

    Herruzo, R; Vizcaino, M J; Herruzo, I

    2010-05-01

    The use of alcohol-based hand rubs serves to reduce hospital-acquired infections. Many products of this type are now on offer and it is essential to know how to rank their efficacy. A sequence of tests is proposed here to compare any given new alcohol-based solution against the reference solution (60% 2-isopropyl-alcohol) with 30 s of contact time: (i) in vitro (with pig skin as carrier) testing of >30 species of microorganism; (ii) in vitro assessment of residual efficacy (after 30 min of drying); (iii) in vivo study of transient microbiota (modification of the EN 1500 standard procedure) using four ATCC strains; (iv) in vivo study of resident hand microbiota. After performing the in vitro evaluation of seven alcohol-based hand rubs, the two most efficacious (chlorhexidine-quac-alcohol and mecetronium- alcohol) were chosen and studied, comparatively with the reference solution (60% isopropyl alcohol), in vitro (for chemical sustainability on the skin) and in vivo (against transient and resident microbiota). Chlorhexidine-quac-alcohol proved to be significantly superior to mecetronium-alcohol or the reference solution in all tests, except against resident microbiota for which the improvement was not statistically significant. PMID:19624506

  4. DISINFECTION BYPRODUCTS: THE NEXT GENERATION

    EPA Science Inventory

    Disinfection of drinking water is rightly hailed as a major public health triumph of the 20th Century. Before widespread disinfection of drinking water in the U.S. and Europe, millions of people died from infectious waterborne diseases, such as typhoid and cholera. The microbia...

  5. Sanitizers and Disinfectants Guide. Revised

    ERIC Educational Resources Information Center

    Healthy Schools Network, Inc., 2012

    2012-01-01

    Sanitizers and disinfectants can play an important role in protecting public health. They are designed to kill "pests," including infectious germs and other microorganisms such as bacteria, viruses, and fungi. Unfortunately, sanitizers and disinfectants also contain chemicals that are "pesticides." Exposure to persistent toxic chemicals in…

  6. Multi-purpose HealthCare Telemedicine Systems with mobile communication link support

    PubMed Central

    Kyriacou, E; Pavlopoulos, S; Berler, A; Neophytou, M; Bourka, A; Georgoulas, A; Anagnostaki, A; Karayiannis, D; Schizas, C; Pattichis, C; Andreou, A; Koutsouris, D

    2003-01-01

    The provision of effective emergency telemedicine and home monitoring solutions are the major fields of interest discussed in this study. Ambulances, Rural Health Centers (RHC) or other remote health location such as Ships navigating in wide seas are common examples of possible emergency sites, while critical care telemetry and telemedicine home follow-ups are important issues of telemonitoring. In order to support the above different growing application fields we created a combined real-time and store and forward facility that consists of a base unit and a telemedicine (mobile) unit. This integrated system: can be used when handling emergency cases in ambulances, RHC or ships by using a mobile telemedicine unit at the emergency site and a base unit at the hospital-expert's site, enhances intensive health care provision by giving a mobile base unit to the ICU doctor while the telemedicine unit remains at the ICU patient site and enables home telemonitoring, by installing the telemedicine unit at the patient's home while the base unit remains at the physician's office or hospital. The system allows the transmission of vital biosignals (3–12 lead ECG, SPO2, NIBP, IBP, Temp) and still images of the patient. The transmission is performed through GSM mobile telecommunication network, through satellite links (where GSM is not available) or through Plain Old Telephony Systems (POTS) where available. Using this device a specialist doctor can telematically "move" to the patient's site and instruct unspecialized personnel when handling an emergency or telemonitoring case. Due to the need of storing and archiving of all data interchanged during the telemedicine sessions, we have equipped the consultation site with a multimedia database able to store and manage the data collected by the system. The performance of the system has been technically tested over several telecommunication means; in addition the system has been clinically validated in three different countries using

  7. Occurrence and exposures to disinfectants and disinfection by-products

    SciTech Connect

    Cumming, R.B.; Jolley, R.L.

    1992-12-31

    Disinfection by-products are associated with all chemical disinfectants. The concentration and toxic nature of the disinfection byproducts (DBPs) is a direct function of the chemical nature of the disinfectant itself and/or of the chemical reactions of the disinfectant with reaction substrates in the water, especially organic constituents. A principal advantage of biological and physical water treatment processes, such as filtration, is the lack of chemical reactions producing disinfectant-related DBPs. The use of the highest quality source water available is important for minimization of DBP formation. In lieu of such high quality water, improvement of water quality by removal of DBP precursors through filtration or other means before application of chemical disinfectants is important. Most, if not all, water treatment experts are aware of these simplistic axioms. In view of the increasing knowledge being developed concerning DBPs including the identification of ``new`` DBPs, prudence dictates minimization of DBP formation. Wholesome drinking water is perhaps the biggest economic bargain available to consumers. The cost-effectiveness of water quality improvement should be evaluated with that in mind.

  8. Occurrence and exposures to disinfectants and disinfection by-products

    SciTech Connect

    Cumming, R.B.; Jolley, R.L.

    1992-01-01

    Disinfection by-products are associated with all chemical disinfectants. The concentration and toxic nature of the disinfection byproducts (DBPs) is a direct function of the chemical nature of the disinfectant itself and/or of the chemical reactions of the disinfectant with reaction substrates in the water, especially organic constituents. A principal advantage of biological and physical water treatment processes, such as filtration, is the lack of chemical reactions producing disinfectant-related DBPs. The use of the highest quality source water available is important for minimization of DBP formation. In lieu of such high quality water, improvement of water quality by removal of DBP precursors through filtration or other means before application of chemical disinfectants is important. Most, if not all, water treatment experts are aware of these simplistic axioms. In view of the increasing knowledge being developed concerning DBPs including the identification of new'' DBPs, prudence dictates minimization of DBP formation. Wholesome drinking water is perhaps the biggest economic bargain available to consumers. The cost-effectiveness of water quality improvement should be evaluated with that in mind.

  9. Orion Multi-Purpose Crew Vehicle Active Thermal Control and Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Boehm, Paul; Cross, Cynthia D.; Rains, George Edward

    2014-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in September of 2014. The development of the Orion Active Thermal Control (ATCS) and Environmental Control and Life Support (ECLS) System, focused on the integrating the components into the EFT1 vehicle and preparing them for launch. Work also has started on preliminary design reviews for the manned vehicle. Additional development work is underway to keep the remaining component progressing towards implementation on the flight tests of EM1 in 2017 and of EM2 in 2020. This paper covers the Orion ECLS development from April 2013 to April 2014.

  10. Urban photogrammetric data base for multi-purpose cadastral-based information systems: the Riyadh city case

    NASA Astrophysics Data System (ADS)

    Al-garni, Abdullah M.

    Urban information systems are economic resources that can benefit decision makers in the planning, development, and management of urban projects and resources. In this research, a conceptual model-based prototype Urban Geographic Information System (UGIS) is developed. The base maps used in developing the system and acquiring visual attributes are obtained from aerial photographs. The system is a multi-purpose parcel-based one that can serve many urban applications such as public utilities, health centres, schools, population estimation, road engineering and maintenance, and many others. A modern region in the capital city of Saudi Arabia is used for the study. The developed model is operational for one urban application (population estimation) and is tested for that particular application. The results showed that the system has a satisfactory accuracy and that it may well be promising for other similar urban applications in countries with similar demographic and social characteristics.

  11. Orion Multi-Purpose Crew Vehicle Active Thermal Control and Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Rains, George Edward

    2013-01-01

    The Orion Multi-Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in 2014. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the completing the components which are on EFT1. Additional development work has been done to keep the remaining component progressing towards implementation for a flight tests in of EM1 in 2017 and in and EM2 in 2020. This paper covers the Orion ECLS development from April 2012 to April 2013.

  12. Environmental assessment for the reuse of TNX as a multi-purpose pilot plant campus at the Savannah River Site

    SciTech Connect

    1998-07-01

    The Department of Energy (DOE) prepared this environmental assessment (EA) to analyze the potential environmental and safety impacts of DOE planning to allow asset reuse of the TNX Area at the Savannah River Site (SRS) located near Aiken, South Carolina. The proposed action would include providing for a location for the Centers of Excellence at or adjacent to SRS and entering into a cooperative agreement with a non-profit management and operations (management firm) contractor to operate and market the TNX facilities and equipment. The area (formerly TNX) would be called a Multi-Purpose Pilot Plant Campus (MPPC) and would be used: (1) as location for technology research, development, demonstration, and commercial operations; (2) to establish partnerships with industry to develop applied technologies for commercialization; and (3) serve as administrative headquarters for Centers of Excellence in the program areas of soil remediation, radioecology, groundwater contamination, and municipal solid waste minimization.

  13. [Hydrogen peroxide, chloramine T and chlorhexidrine in the disinfection of acrylic resin].

    PubMed

    Czerwińska, W; Kedzia, A; Kałowski, M

    1978-01-01

    The effectiveness of 3% h drogen peroxide, 5% chloramine T and 0,5% chlorhexidine gluconate solutions in disinfection of acrylic resine plates massively infected with oral flora was analysed. The acrylic resine plates used for investigations, were infected in vitro with mixed salivary flora characterized by small numbers of yeast-like fungi (1st group), or great number of these microorganisms (2nd group). Infected plates were exposed to solutions of analysed disinfectants during various time periods. After rinsing or inactivation of disinfectant residues, acrylic plates were put into bacteriological medium and incubated during 7 days period in 37 degrees C. The results of this study indicated the effectiveness of acrylic plates disinfection to be dependent on used disinfectant, time of exposition, and microorganisms present on the surface of acrylic resine. The solutions of disinfectants were less active in the cases of plates infected with material containing great numbers of yeast-like microorganisms. Among analysed disinfectants 0,5% solution of chlorhexidine was characterized by most effective and rapid activity, whereas 3% solution of hydrogen peroxide was found to be the least effective. PMID:364448

  14. Dental unit waterlines disinfection using hypochlorous acid-based disinfectant

    PubMed Central

    Shajahan, Irfana Fathima; Kandaswamy, D; Srikanth, Padma; Narayana, L Lakshmi; Selvarajan, R

    2016-01-01

    Objective: The purpose of the study was to investigate the efficacy of a new disinfectant to disinfect the dental unit waterlines. Materials and Methods: New dental unit waterlines were installed in 13 dental chairs, and biofilm was allowed to grow for 10 days. Disinfection treatment procedure was carried out in the 12 units, and one unit was left untreated. The dental unit waterlines were removed and analyzed using the scanning electron microscope (SEM) (TESCAN VEGA3 SBU). Result: On examination, SEM images showed that there was no slime layer or bacterial cells seen in any of the 12 cut sections obtained from the treated dental waterlines which mean that there was no evident of biofilm formation. Untreated dental unit waterlines showed a microbial colonization with continuous filamentous organic matrix. There was significant biofilm formation in the control tube relative to the samples. Conclusion: The tested disinfectant was found to be effective in the removal of biofilm from the dental unit waterlines. PMID:27563184

  15. Effect of disinfectants on pseudomonads colonized on the interior surface of PVC pipes.

    PubMed Central

    Anderson, R L; Holland, B W; Carr, J K; Bond, W W; Favero, M S

    1990-01-01

    We investigated the effect of disinfectants on microbial contamination present on the interior surface of polyvinyl chloride (PVC) pipes filled with 600 ml of water contaminated with Pseudomonas pickettii and P. aeruginosa. After eight weeks, water was removed, and the test pipes exposed to various types of aqueous disinfectants. Disinfectant samples were removed, neutralized, and examined for recovery of microorganisms by membrane filtration. After seven-days exposure, disinfectant solutions were removed and pipes filled with sterile distilled water. Water was examined by membrane filtration at seven-day intervals to determine whether the organisms had survived in the pipes. Colonization of PVC surfaces were examined during each study phase by scanning electron-microscopy (SEM). P. aeruginosa was isolated directly from iodophor disinfectant, phenolic germicide, and iodophor antiseptic solutions. After addition of sterile water, P. aeruginosa was recovered from PVC pipes previously exposed to chlorine, phenolic, quaternary-ammonium, and iodophor disinfectants; P. pickettii was recovered from water in pipes treated with iodophor disinfectant, chlorine, and ethanol. The existence of glycocalyx-like cellular masses on the interior wall of PVC pipes most likely protected embedded organisms from the microbicidal action of some of the disinfectants tested and served as the reservoir for continuous contamination. Images FIGURE 1 PMID:2293797

  16. 9 CFR 71.12 - Sodium orthophenylphenate as permitted disinfectant for premises infected with tuberculosis.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... proportion of at least one pound to 12 gallons of water is permitted in tuberculosis eradication work for... solution shall be heated to 120 °F. and higher in very cold weather, to insure effective disinfection....

  17. DESIGN MANUAL: MUNICIPAL WASTEWATER DISINFECTION

    EPA Science Inventory

    This manual provides a comprehensive source of information to be used in the design of disinfection facilities for municipal wastewater treatment plants. he manual includes design information on halogenation/dehalogenation, ozonation, and ultraviolet radiation. he manual presents...

  18. RISK ASSESSMENT OF WASTEWATER DISINFECTION

    EPA Science Inventory

    A risk assessment data base is presented for several waste-water disinfection alternatives, including chlorination, ozonation, chlorination/dechlorination, and ultraviolet radiation. The data base covers hazards and consequences related to onsite use and transportation of the dis...

  19. Efficacies of selected disinfectants against Mycobacterium tuberculosis.

    PubMed

    Best, M; Sattar, S A; Springthorpe, V S; Kennedy, M E

    1990-10-01

    The activities of 10 formulations as mycobactericidal agents in Mycobacterium tuberculosis-contaminated suspensions (suspension test) and stainless steel surfaces (carrier test) were investigated with sputum as the organic load. The quaternary ammonium compound, chlorhexidine gluconate, and an iodophor were ineffective in all tests. Ethanol (70%) was effective against M. tuberculosis only in suspension in the absence of sputum. Povidone-iodine was not as efficacious when the test organism was dried on a surface as it was in suspension, and its activity was further reduced in the presence of sputum. Sodium hypochlorite required a higher concentration of available chlorine to achieve an effective level of disinfection than did sodium dichloroisocyanurate. Phenol (5%) was effective under all test conditions, producing at least a 4-log10 reduction in CFU. The undiluted glutaraldehyde-phenate solution was effective against M. tuberculosis and a second test organism, Mycobacterium smegmatis, even in the presence of dried sputum, whereas the diluted solution (1:16) was only effective against M. smegmatis in the suspension test. A solution of 2% glutaraldehyde was effective against M. tuberculosis. This investigation presents tuberculocidal efficacy data generated by methods simulating actual practices of routine disinfection. PMID:2121783

  20. Iodine Tagging Velocimetry and Mechanism in the Hypersonic Near Wake of a MultiPurpose Crew Vehicle

    NASA Technical Reports Server (NTRS)

    Balla, R. Jeffrey

    2013-01-01

    This study demonstrates a new molecular tagging velocimetry (MTV) method for velocity measurements of high speed flow. It demonstrates offbody Iodine Tagging Velocimetry (ITV) in the hypersonic near wake of a MultiPurpose Crew Vehicle (MPCV) model. Experiments are performed in the NASA-Langley 31-inch Mach 10 air wind tunnel. A 0.5% I2 / N2 mixture is seeded on the leeward backshell of the model using a pressure tap. I2 laser-induced fluorescence is excited along a 5.5 mm line using an ArF excimer laser near 193 nm. Results indicate I2 absorbs at least 2 photons to produce iodine ions and electrons. These recombine as the tagged region is displaced downstream to produce I (2P3/2) whose emission is monitored at 206 nm. Results at P0 = 2.41 MPa (350 psi), T0 = 990K, and 10 micro-sec transit times produce velocities from 630-820 m/sec across the I2 seeded jet at a distance of 38.2 mm (25.5 jet diameters) downstream from the jet orifice. Maximum wake jet velocities near the shear layer are 59% of freestream velocity.

  1. Effects of disinfection on the molecular detection of porcine epidemic diarrhea virus.

    PubMed

    Bowman, Andrew S; Nolting, Jacqueline M; Nelson, Sarah W; Bliss, Nola; Stull, Jason W; Wang, Qiuhong; Premanandan, Christopher

    2015-09-30

    Routine detection of porcine epidemic diarrhea virus (PEDV) is currently limited to RT-PCR but this test cannot distinguish between viable and inactivated virus. We evaluated the capability of disinfectants to both inactivate PEDV and sufficiently damage viral RNA beyond RT-PCR detection. Five classes of disinfectants (phenol, quaternary ammonium compound, sodium hypochlorite, oxidizing agent, and quaternary ammonium/glutaraldehyde combination) were evaluated in vitro at varying concentrations, both in the presence and absence of swine feces, and at three different temperatures. No infectious PEDV was recovered after treatment with evaluated disinfectants. Additionally, all tested disinfectants except for 0.17% sodium hypochlorite dramatically reduced qRT-PCR values. However, no disinfectants eliminated RT-PCR detection of PEDV across all replicates; although, 0.52%, 1.03% and 2.06% solutions of sodium hypochlorite and 0.5% oxidizing agent did intermittently produce RT-PCR negatives. To simulate field conditions in a second aim, PEDV was applied to pitted aluminum coupons, which were then treated with either 2.06% sodium hypochlorite or 0.5% oxidizing agent. Post-treatment surface swabs of the coupons tested RT-PCR positive but were not infectious to cultured cells or naïve pigs. Ultimately, viable PEDV was not detected following application of each of the tested disinfectants, however in most cases RT-PCR detection of viral RNA remained. RT-PCR detection of PEDV is likely even after disinfection with many commercially available disinfectants. PMID:26072369

  2. [Microbiological assesssment of efficiency chemothermal disinfection of blood contaminated hospital textiles].

    PubMed

    Röhm-Rodowald, Ewa; Jakimiak, Bozenna; Podgórska, Marta; Chojecka, Agnieszka

    2010-01-01

    Thermal disinfection should be applied to laundering procedures of hospital textiles contaminated with blood. Currently, there is an increasing number of hospital textiles composed of cotton-polyester blends that cannot endure high temperatures of thermal disinfection. Besides, decreasing the temperature of chemothermal disinfection enhances the possibility of micro-organisms to survive the laundering procedure. The aim of this study was to prepare a new method for the microbiological evaluation of disinfecting laundering procedures for hospital textiles contaminated with blood. The bactericidal activity of chemical disinfectants for chemothermal disinfection was determined by simulating a laundering procedure for hospital textiles in the laboratory according to procedure of National Institute of Hygiene - DF/05/03. Bioindicators cotton carriers inoculated with Enterococcus faecium were used for determinating the antibacterial effects for hospital textiles contaminated with blood. High concentrations of bovine albumin and/or sheep erythrocytes were used as substrate for simulating human blood. The results showed that the bactericidal activity of chemical disinfectants for chemothermal disinfection hospital textiles in the event of massive organic contamination--heavily soiled with blood, shall be evaluated using carrier test in following conditions: test organism- Enterococcus faecium, interfering substances--6 g/l bovine albumin solution added to preparation. PMID:21365871

  3. Evaluation of properties of irreversible hydrocolloid impression materials mixed with disinfectant liquids

    PubMed Central

    Amalan, Arul; Ginjupalli, Kishore; Upadhya, Nagaraja

    2013-01-01

    Background: Addition of disinfectant to irreversible hydrocolloid impression materials can eliminate the disinfection step to avoid dimensional changes associated with it. The aim of the present study was to evaluate the effect of various disinfectant mixing liquids on the properties of commercially available irreversible hydrocolloid impression materials. Materials and Methods: Four commercially available irreversible hydrocolloid impression materials (Zelgan, Vignette, Tropicalgin, and Algitex) were mixed with disinfectant liquid containing chlorhexidine (0.1 and 0.2%) and sodium hypochlorite (0.1 and 0.5%). After mixing with disinfectant liquids, materials were evaluated for pH changes during gelation, gelation time, flow, gel strength, permanent deformation and detail reproduction. Results: Significant changes in gelation time were observed in irreversible hydrocolloid impression materials upon mixing with disinfectant liquids. In general, chlorhexidine increased the gelation time, whereas sodium hypochlorite reduced it. However, no significant changes in the flow were observed both with chlorhexidine and sodium hypochlorite. Gel strength was found to decrease when mixed with chlorhexidine, whereas an increase in gel strength was observed upon mixing with sodium hypochlorite. Permanent deformation of the most irreversible hydrocolloid impression materials was below the specification limit even after mixing with disinfectant liquids. Sodium hypochlorite significantly reduced the surface detail reproduction, whereas no change in detail reproduction was observed with chlorhexidine. Conclusion: Chlorhexidine solution can be used to mix irreversible hydrocolloid impression materials in regular dental practice as it did not significantly alter the properties. This may ensure effective disinfection of impressions. PMID:23878566

  4. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.54 Maximum residual disinfectant level...

  5. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Goals and Maximum Residual Disinfectant Level Goals § 141.54 Maximum residual disinfectant level...

  6. Multi-time scale Climate Informed Stochastic Hybrid Simulation-Optimization Model (McISH model) for Multi-Purpose Reservoir System

    NASA Astrophysics Data System (ADS)

    Lu, M.; Lall, U.

    2013-12-01

    In order to mitigate the impacts of climate change, proactive management strategies to operate reservoirs and dams are needed. A multi-time scale climate informed stochastic model is developed to optimize the operations for a multi-purpose single reservoir by simulating decadal, interannual, seasonal and sub-seasonal variability. We apply the model to a setting motivated by the largest multi-purpose dam in N. India, the Bhakhra reservoir on the Sutlej River, a tributary of the Indus. This leads to a focus on timing and amplitude of the flows for the monsoon and snowmelt periods. The flow simulations are constrained by multiple sources of historical data and GCM future projections, that are being developed through a NSF funded project titled 'Decadal Prediction and Stochastic Simulation of Hydroclimate Over Monsoon Asia'. The model presented is a multilevel, nonlinear programming model that aims to optimize the reservoir operating policy on a decadal horizon and the operation strategy on an updated annual basis. The model is hierarchical, in terms of having a structure that two optimization models designated for different time scales are nested as a matryoshka doll. The two optimization models have similar mathematical formulations with some modifications to meet the constraints within that time frame. The first level of the model is designated to provide optimization solution for policy makers to determine contracted annual releases to different uses with a prescribed reliability; the second level is a within-the-period (e.g., year) operation optimization scheme that allocates the contracted annual releases on a subperiod (e.g. monthly) basis, with additional benefit for extra release and penalty for failure. The model maximizes the net benefit of irrigation, hydropower generation and flood control in each of the periods. The model design thus facilitates the consistent application of weather and climate forecasts to improve operations of reservoir systems. The

  7. In-vitro analysis of the microbicidal activity of 6 contact lens care solutions

    PubMed Central

    2012-01-01

    Background Contact lens-related infections are often associated with inadequate contact lens hygiene, and therefore, contact lens care products should be able to sufficiently minimise the amount of pathogens that are responsible for these infections. In 2001, the EN ISO 14729 was introduced to ensure adequate disinfection efficacy of contact lens care solutions, but this norm has recently been criticised. Methods In this study, six frequently used contact lens care solutions were retested according to the Stand Alone Test of the EN ISO 14729 (2001). The Stand Alone Test is a quantitative suspension test. In addition, the products were tested in a modified setting adding an organic load. The load was a mixture of human blood serum, lysozyme, and mucine, which resembles tear fluid. Results The criteria of the Stand Alone Test recommended in EN ISO 14729 were only met by Aosept Plus. This 3% hydrogen-peroxide-based contact lens care solution attained a reduction factor of > 5 log units for bacteria and > 4 for fungi in all cases. Two further contact lens care solutions, Blue Vision and Optifree Replenish, met the criteria of a reduction factor of > 3 log units for bacteria and > 1 log unit for fungi, but only in the presence of artificial tear fluid. The three remaining products did not exhibit adequate disinfecting efficacy, at least against one of the tested microorganisms. Conclusions Through the observation that the artificial tear fluid used in this study influences the disinfecting efficacy of contact lens care solutions, especially that of multi-purpose solutions, in a different way than does albumin, mucine, or even the organic load suggested in EN ISO 14729, it becomes obvious that the test conditions in the EN ISO 14729 should be revised in order to create more realistic conditions, e.g., by using a more realistic artificial tear fluid. Furthermore, we suggest adapting the EN ISO 14729 to the European test hierarchy for chemical disinfectants and antiseptics

  8. [Disinfection problems in food hygiene].

    PubMed

    Shandala, M G

    2013-01-01

    Based on the main tasks of hygienic support of balanced diet of the population, we consider different issues of disinfection contribution in:food safety, prevention of the emergence and dissemination of relevant infectious and noninfectious diseases, quality disruption of foodstuffs under various biological pathogens (bacteria, protozoa, helminthes, arthropods, rodents), which are the causative agents of human disease vectors or natural reservoirs of pathogens. The need to involve the disinfection competence in ensuring the safety and security of canned food, as well as the products long-term storage is stressed. Paper deals with factors, key for effectiveness of disinfection and, therefore, epidemiological and hygienic safety of the equipment and facilities, food industries and food service. We consider the need to take into account advantageous properties and shortcomings of some groups of disinfectants in terms both of microbicidal effectiveness and of their toxic safety, compatibility with the materials of processed objects, ease of use, etc. The focus is made on the need to select some disinfection technology in terms of the primary objective and current conditions taking the type and attributes of the relevant biological pathogens into account. PMID:24000699

  9. Investigating a multi-purpose target for electron linac based photoneutron sources for BNCT of deep-seated tumors

    NASA Astrophysics Data System (ADS)

    Masoudi, S. Farhad; Rasouli, Fatemeh S.

    2015-08-01

    Recent studies in BNCT have focused on investigating appropriate neutron sources as alternatives for nuclear reactors. As the most prominent facilities, the electron linac based photoneutron sources benefit from two consecutive reactions, (e, γ) and (γ, n). The photoneutron sources designed so far are composed of bipartite targets which involve practical problems and are far from the objective of achieving an optimized neutron source. This simulation study deals with designing a compact, optimized, and geometrically simple target for a photoneutron source based on an electron linac. Based on a set of MCNPX simulations, tungsten is found to have the potential of utilizing as both photon converter and photoneutron target. Besides, it is shown that an optimized dimension for such a target slows-down the produced neutrons toward the desired energy range while keeping them economy, which makes achieving the recommended criteria for BNCT of deep-tumors more available. This multi-purpose target does not involve complicated designing, and can be considered as a significant step toward finding application of photoneutron sources for in-hospital treatments. In order to shape the neutron beam emitted from such a target, the beam is planned to pass through an optimized arrangement of materials composed of moderators, filters, reflector, and collimator. By assessment with the recommended in-air parameters, it is shown that the designed beam provides high intensity of desired neutrons, as well as low background contamination. The last section of this study is devoted to investigate the performance of the resultant beam in deep tissue. A typical simulated liver tumor, located within a phantom of human body, was subjected to the irradiation of the designed spectrum. The dosimetric results, including evaluated depth-dose curves and carried out in-phantom parameters show that the proposed configuration establishes acceptable agreement between the appropriate neutron intensity, and

  10. Monte Carlo simulations of gamma-ray space telescopes: a BoGEMMS multi-purpose application

    NASA Astrophysics Data System (ADS)

    Fioretti, Valentina; Bulgarelli, Andrea; Tavani, Marco; Marisaldi, Martino; Sabatini, Sabina; Malaguti, Giuseppe; Trifoglio, Massimo; Gianotti, Fulvio

    2014-07-01

    After the development of a BoGEMMS (Bologna Geant4 Multi-Mission Simulator) template for the background study of X-ray telescopes, a new extension is built for the simulation of a Gamma-ray space mission (e.g. AGILE, Fermi), conceived to work as a common, multi-purpose framework for the present and future electron tracking gamma-ray space telescopes. The Gamma-ray extension involves the Geant4 mass model, the physics list and, more important, the production and treatment of the simulation output. From the user point of view, the simulation set-up follows a tree structure, with the main level being the selection of the simulation framework (the general, X-ray or gamma-ray application) and the secondary levels being the detailed configuration of the geometry and the output format. The BoGEMMS application to Gamma-ray missions has been used to evaluate the instrument performances of a new generation of Gamma-ray telescopes (e.g. Gamma-Light), and a full simulation of the AGILE mission is currently under construction, to scientifically validate and calibrate the simulator with real in-space data sets. A complete description of the BoGEMMS Gamma-ray framework is presented here, with an overview of the achieved results for the potential application to present and future experiments (e.g., GAMMA-400 and Gamma-Light). The evaluation of the photon conversion efficiency to beta particle pairs and the comparison to tabulated data allows the preliminary physical validation of the overall architecture. The Gamma-ray module application for the study of the Gamma-Light instrument performances is reported as reference test case.

  11. Effect of different disinfecting procedures on the hardness and color stability of two maxillofacial elastomers over time

    PubMed Central

    ELENI, Panagiota N.; KROKIDA, Magdalini K.; POLYZOIS, Gregory L.; GETTLEMAN, Lawrence

    2013-01-01

    Objective: Disinfection procedures often cause deterioration in a maxillofacial prosthesis. Color and hardness alterations could lead to a replacement of the prosthesis. Material and Methods: An experimental chlorinated polyethylene (CPE) and a commercial polydimethyl siloxane (PDMS) sample were treated with four different disinfection procedures for a period which simulates 1 year of clinical service. The applied disinfection procedures included microwave exposure and immersion in three solutions, sodium hypochlorite, neutral soap and a commercial disinfecting soap. Shore A hardness (ΔΗ) and color differences (ΔΕ) were determined before and after each procedure. All data were analyzed by Two Way Analysis of Variance (ANOVA) and Tukey's post hoc tests at a level of α=0.05. Results: The samples presented significant alterations in color and hardness after the different disinfection treatments. The color differences (ΔΕ) were at least eye detectable in all cases and clinically unacceptable in most of the cases, with values ranging from 1.51 to 4.15 and from 1.54 to 5.92 for the PDMS and CPE material, respectively. Hardness was decreased after all the disinfection procedures in the PDMS, while for the CPE, a decrement was observed after disinfection with sodium hypochlorite and neutral soap and an increment after microwave exposure and the disinfection with a commercial antimicrobial agent. The PDMS samples presented greater alterations in color and hardness after disinfection with sodium hypochlorite solution, while the microwave exposure caused negligible effects. The CPE samples were affected most after disinfection when treated with neutral soap, and more slightly when disinfected with sodium hypochlorite solution. Conclusions: The disinfection procedures caused alterations in color and hardness of the examined materials. The most suitable disinfection procedure for the PDMS material is microwave exposure, while disinfection with sodium hypochlorite

  12. On the cause of the tailing phenomenon during virus disinfection by chlorine dioxide.

    PubMed

    Sigstam, Thérèse; Rohatschek, Andreas; Zhong, Qingxia; Brennecke, Moritz; Kohn, Tamar

    2014-01-01

    This study investigates the mechanisms underlying the deviation from Chick-Watson kinetics, namely a tailing curve, during the disinfection of viruses by chlorine dioxide (ClO2). Tailing has been previously reported, but is typically attributed to the decay in disinfectant concentration. Herein, it is shown that tailing occurs even at constant ClO2 concentrations. Four working hypothesis to explain the cause of tailing were tested, specifically changes in the solution's disinfecting capacity, aggregation of viruses, resistant virus subpopulations, and changes in the virus properties during disinfection. In experiments using MS2 as a model virus, it was possible to rule out the solution's disinfecting capacity, virus aggregation and the resistant subpopulation as reasons for tailing. Instead, the cause for tailing is the deposition of an adduct onto the virus capsid over the course of the experiment, which protects the viruses. This adduct could easily be removed by washing, which restored the susceptibility of the viruses to ClO2. This finding highlights an important shortcoming of ClO2, namely its self-limiting effect on virus disinfection. It is important to take this effect into account in treatment applications to ensure that the water is sufficiently disinfected before human consumption. PMID:24139105

  13. Generation of ozone foam and its application for disinfection

    NASA Astrophysics Data System (ADS)

    Hiragaki, Keisuke; Ishimaru, Tomiya; Nakanishi, Masaru; Muraki, Ryouji; Nieda, Masanori; Yamabe, Chobei

    2015-07-01

    Generated ozone foam was applied to the disinfection of Pseudomonas fluorescens. The effect of disinfection has been confirmed experimentally and new equipment for the disinfection of hands using this ozone foam has been put on the market for the practical use. The ozone foam was produced in the foam generator after mixing the water including surfactant (30 mL/min) and air including ozone (1000 ppm = 2.14 g/m3 ~ 1600 ppm = 3.4 g/m3, 300 mL/min). The liquid-to-gas ratio is 100 L/m3. The concentration of dissolved ozone in the thin liquid films of the bubbles was about 3 mg/L which was measured by the chemical method of the KI absorption and titration of sodium thiosulfate solution. The disinfection test samples were prepared using the PET disk on which Pseudomonas fluorescens of its number of more than 108 were attached. Test sample was inserted into ozone foam set on the glass plate for one to 6 min. The survival rate log (N/N0 decreased with time and its value of about-2.6 (i.e., ~1/400) was obtained at 6 min (2 min × 3 times repeated). It was also confirmed that the ozone foam was useful for the disinfection of hands. For more effective disinfection (in case of taking a long time for foam melting), the ozone foam was broken by force and changed into ozone water by which the survival rate decreased ×4 (i.e., N/N0 = 1/10 000) at 4 ~ 6 min. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  14. Disinfection of Human Teeth for Educational Purposes.

    ERIC Educational Resources Information Center

    Tate, William H.; White, Robert S.

    1991-01-01

    A study investigated the efficacy of glutaraldehyde and several other disinfectants for disinfecting teeth to be used for teaching and research, as an alternative to autoclaving for teeth with amalgam restorations. Results indicate that formalin was the only disinfectant that penetrated tooth pulp chambers in effective antimicrobial…

  15. Review of water disinfection techniques

    NASA Technical Reports Server (NTRS)

    Colombo, Gerald V.; Sauer, Richard L.

    1987-01-01

    Throughout the history of manned space flight the supply of potable water to the astronauts has presented unique problems. Of particular concern has been the microbiological quality of the potable water. This has required the development of both preflight water system servicing procedures to disinfect the systems and inflight disinfectant addition and monitoring devices to ensure continuing microbiological control. The disinfectants successfully used to date have been aqueous chlorine or iodine. Because of special system limitations the use of iodine has been the most successful for inflight use and promises to be the agent most likely to be used in the future. Future spacecraft potable, hygiene, and experiment water systems will utilize recycled water. This will present special problems for water quality control. NASA is currently conducting research and development to solve these problems.

  16. New disinfection and sterilization methods.

    PubMed Central

    Rutala, W. A.; Weber, D. J.

    2001-01-01

    New disinfection methods include a persistent antimicrobial coating that can be applied to inanimate and animate objects (Surfacine), a high-level disinfectant with reduced exposure time (ortho-phthalaldehyde), and an antimicrobial agent that can be applied to animate and inanimate objects (superoxidized water). New sterilization methods include a chemical sterilization process for endoscopes that integrates cleaning (Endoclens), a rapid (4-hour) readout biological indicator for ethylene oxide sterilization (Attest), and a hydrogen peroxide plasma sterilizer that has a shorter cycle time and improved efficacy (Sterrad 50). PMID:11294738

  17. EPIDEMIOLOGIC STUDIES OF DISINFECTANTS AND DISINFECTANT BY-PRODUCTS

    EPA Science Inventory

    This article provides a review of the epidemiologic evidence for human health effects that may be associated with the disinfection of drinking water. An epidemiologic study attempts to link human health effects with exposure to a specific agent (e.g., DBCM), agents (e.g., THMs or...

  18. 9 CFR 96.10 - Uncertified casings; transportation for disinfection; original shipping containers; disposition...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... hydrochloric acid containing not less than 35 percent actual HCl; mix thoroughly and allow the solution to... hydrochloric acid. (This solution may be utilized in the disinfection of casings as prescribed in § 96.13.) (2..., raincoat and goggles should be observed. An acid solution such as vinegar shall be kept readily...

  19. 9 CFR 96.10 - Uncertified casings; transportation for disinfection; original shipping containers; disposition...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... hydrochloric acid containing not less than 35 percent actual HCl; mix thoroughly and allow the solution to... hydrochloric acid. (This solution may be utilized in the disinfection of casings as prescribed in § 96.13.) (2..., raincoat and goggles should be observed. An acid solution such as vinegar shall be kept readily...

  20. 9 CFR 96.10 - Uncertified casings; transportation for disinfection; original shipping containers; disposition...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... hydrochloric acid containing not less than 35 percent actual HCl; mix thoroughly and allow the solution to... hydrochloric acid. (This solution may be utilized in the disinfection of casings as prescribed in § 96.13.) (2..., raincoat and goggles should be observed. An acid solution such as vinegar shall be kept readily...

  1. 9 CFR 96.10 - Uncertified casings; transportation for disinfection; original shipping containers; disposition...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... hydrochloric acid containing not less than 35 percent actual HCl; mix thoroughly and allow the solution to... hydrochloric acid. (This solution may be utilized in the disinfection of casings as prescribed in § 96.13.) (2..., raincoat and goggles should be observed. An acid solution such as vinegar shall be kept readily...

  2. The effects of disinfectant foam on microbial biofilms.

    PubMed

    Sreenivasan, Prem K; Chorny, Roberto C

    2005-01-01

    This investigation examined the effects of common aqueous biocides and disinfectant foams derived from them on Pseudomonas aeruginosa biofilms. Biofilms were grown on stainless steel coupons under standardised conditions in a reactor supplemented with low concentrations of organic matter to simulate conditions prevalent in industrial systems. Five-day-old biofilms formed under ambient conditions with continuous agitation demonstrated a low coefficient of variation (5.809%) amongst viable biofilm bacteria from independent trials. Scanning electron microscopy revealed biofilms on coupons with viable biofilm bacteria observed by confocal microscopy. An aqueous solution of a common foaming agent amine oxide (AO) produced negligible effects on bacterial viability in biofilms (p>0.05). However, significant biofilm inactivation was noted with aqueous solutions of common biocides (peracetic acid, sodium hypochlorite, sodium ethylenediaminetetraacetic acid) with or without AO (p<0.05). Aereation of a mixture of AO with each of these common biocides resulted in significant reductions in the viability of biofilm bacteria (p<0.05). In contrast, limited effects were noted by foam devoid of biocides. A relationship between microbial inactivation and the concentration of biocide in foam (ranging from 0.1-0.5%) and exposure period were noted (p<0.05). Although, lower numbers of viable biofilm bacteria were recovered after treatment with the disinfectant foam than by the cognate aqueous biocide, significant differences between these treatments were not evident (p>0.05). In summary, the studies revealed significant biofilm inactivation by biocidal foam prepared with common biocides. Validation of foam disinfectants in controlled trials at manufacturing sites may facilitate developments for clean in place applications. Advantages of foam disinfectants include reductions in the volumes of biocides for industrial disinfection and in their disposal after use. PMID:16167393

  3. Postoutbreak disinfection of mobile equipment.

    PubMed

    Alphin, R L; Ciaverelli, C D; Hougentogler, D P; Johnson, K J; Rankin, M K; Benson, E R

    2010-03-01

    Current control strategies for avian influenza virus, exotic Newcastle disease, and other highly contagious poultry diseases include surveillance, quarantine, depopulation, disposal, and decontamination. Skid steer loaders and other mobile equipment are extensively used during depopulation and disposal. Movement of contaminated equipment has been implicated in the spread of disease in previous outbreaks. One approach to equipment decontamination is to power wash the equipment, treat with a liquid disinfectant, change any removable filters, and let it sit idle for several days. In this project, multiple disinfectant strategies were individually evaluated for their effectiveness at inactivating Newcastle disease virus (NDV) on mechanical equipment seeded with the virus. A small gasoline engine was used to simulate typical mechanical equipment. A high titer of LaSota strain, NDV was applied and dried onto a series of metal coupons. The coupons were then placed on both interior and exterior surfaces of the engine. Liquid disinfectants that had been effective in the laboratory were not as effective at disinfecting the engine under field conditions. Indirect thermal fog showed a decrease in overall virus titer or strength. Direct thermal fog was more effective than liquid spray application or indirect thermal fog application. PMID:20521731

  4. Recycled Water Poses Disinfectant Problem

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1973

    1973-01-01

    Discusses the possible health hazards resulting from released nucleic acid of inactivated viruses, chlorinated nonliving organic molecules, and overestimated reliability of waste treatment standards. Suggests the recycle system use a dual disinfectant such as chlorine and ozone in water treatment. (CC)

  5. Effect of mixing techniques on bacterial attachment and disinfection time of polyether impression material

    PubMed Central

    Guler, Umut; Budak, Yasemin; Ruh, Emrah; Ocal, Yesim; Canay, Senay; Akyon, Yakut

    2013-01-01

    Objective: The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. Materials and Methods: Polyether impression material samples (n = 144) were prepared by hand-mixing or auto-mixing. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used in testing. After incubation, the bacterial colonies were counted and then disinfectant solution was applied. The effect of disinfection solution was evaluated just after the polymerization of impression material and 30 min after polymerization. Differences in adherence of bacteria to the samples prepared by hand-mixing and to those prepared by auto-mixing were assessed by Kruskal-Wallis and Mann-Whitney U-tests. For evaluating the efficiency of the disinfectant, Kruskal-Wallis multiple comparisons test was used. Results: E. coli counts were higher in hand-mixed materials (P < 0.05); no other statistically significant differences were found between hand- and auto-mixed materials. According to the Kruskal-Wallis test, significant differences were found between the disinfection procedures (Z > 2.394). Conclusion: The methods used for mixing polyether impression material did not affect bacterial attachment to impression surfaces. In contrast, the disinfection procedure greatly affects decontamination of the impression surface. PMID:24966729

  6. Multi-Destination and Multi-Purpose Trip Effects in the Analysis of the Demand for Trips to a Remote Recreational Site

    NASA Astrophysics Data System (ADS)

    Martínez-Espiñeira, Roberto; Amoako-Tuffour, Joe

    2009-06-01

    One of the basic assumptions of the travel cost method for recreational demand analysis is that the travel cost is always incurred for a single purpose recreational trip. Several studies have skirted around the issue with simplifying assumptions and dropping observations considered as nonconventional holiday-makers or as nontraditional visitors from the sample. The effect of such simplifications on the benefit estimates remains conjectural. Given the remoteness of notable recreational parks, multi-destination or multi-purpose trips are not uncommon. This article examines the consequences of allocating travel costs to a recreational site when some trips were taken for purposes other than recreation and/or included visits to other recreational sites. Using a multi-purpose weighting approach on data from Gros Morne National Park, Canada, we conclude that a proper correction for multi-destination or multi-purpose trip is more of what is needed to avoid potential biases in the estimated effects of the price (travel-cost) variable and of the income variable in the trip generation equation.

  7. Reducing disinfectant wastage.

    PubMed

    Kaye, S B; Graham, R; McCarthy, K; Green, J R; Damjanovic, V; Austin, M

    1991-01-01

    In order to lower departmental costs in an ophthalmological outpatient department by reducing wastage, the stability of available chlorine at levels of 280 ppm and 560 ppm in litre solutions of sodium dichloroisocyanurate was investigated over a three-week period. There was no significant decay in available chlorine at these levels in solutions kept at 20 degrees C. Sodium dichloroisocyanurate may be prepared on a weekly instead of a daily basis with an annual saving of 1200 pounds to 1400 pounds. PMID:2060659

  8. Effect of iodine disinfectant source and water quality parameters on soluble iodine speciation

    NASA Technical Reports Server (NTRS)

    Silverstein, Joann; Hurst, Charles; Barkley, Robert; Dunham, Andrew

    1993-01-01

    Investigations of iodine species distribution of various aqueous solutions of iodine disinfectants and water from equilibrated suspensions of triodide and pentaiodide resins were done at the University of Colorado for the Center for Space Environmental Health during 1992 and 1993. Direct measurements of three individual iodine species: I(-), I2 and I3(-), were made. In addition three measures of total titratable iodine species were used. It has been found that I2 and I3(-) solutions produce a significant fraction of the non-disinfecting species iodine I(-), ranging from 50 to 80% of added iodine, respectively, at pH values of approximately 5. Correspondingly, I2 solutions produce more than twice the concentration of disinfecting iodine species per mass iodine dose than I3(-) solutions. Both I(-) and I2 species were found in aqeuous extracts of pentaiodide resin, although no soluble species were detected with triiodide resin.

  9. Factors in the Selection of Surface Disinfectants for Use in a Laboratory Animal Setting

    PubMed Central

    Campagna, Michael V; Faure-Kumar, Emmanuelle; Treger, Janet A; Cushman, Jesse D; Grogan, Tristan R; Kasahara, Noriyuki; Lawson, Gregory W

    2016-01-01

    Because surface disinfectants are an important means of pathogen control within laboratory animal facilities, these products must have an appropriate spectrum of antimicrobial activity. However, many other factors must also be considered, including effects on human health, environmental safety, and animal behavior. Aqueous solutions of sodium hypochlorite often are considered to be the ‘gold standard’ for surface disinfection, but these products can be corrosive, caustic, and aversive in odor. This study was designed to identify disinfectants that are as effective as hypochlorite solutions but more acceptable for use in a laboratory animal setting. An antiviral disinfectant-efficacy assay was developed by using viral vectors that expressed green fluorescence protein as surrogates for wild-type viruses of concern in laboratory animals. Efficacy testing revealed that most of the products were highly effective when used against viral vectors in suspension. However, when the disinfectants were challenged by buffering virus in protein or drying virus on nonporous surfaces, the hypochlorite and peroxymonosulfate products performed the best. Review of safety data sheets for the agents indicated that a peroxide-based product was considerably safer than the other products tested and that the pH of most products was not conducive to disposal down a drain. Behavioral testing of Swiss Webster, C57Bl/6, and BALB/c mice showed that the hypochlorite- and peroxide-based products were clearly aversive, given that the mice consistently avoided these products. All of these factors must be considered when choosing the appropriate disinfectant. PMID:27025810

  10. Factors in the Selection of Surface Disinfectants for Use in a Laboratory Animal Setting.

    PubMed

    Campagna, Michael V; Faure-Kumar, Emmanuelle; Treger, Janet A; Cushman, Jesse D; Grogan, Tristan R; Kasahara, Noriyuki; Lawson, Gregory W

    2016-01-01

    Because surface disinfectants are an important means of pathogen control within laboratory animal facilities, these products must have an appropriate spectrum of antimicrobial activity. However, many other factors must also be considered, including effects on human health, environmental safety, and animal behavior. Aqueous solutions of sodium hypochlorite often are considered to be the 'gold standard' for surface disinfection, but these products can be corrosive, caustic, and aversive in odor. This study was designed to identify disinfectants that are as effective as hypochlorite solutions but more acceptable for use in a laboratory animal setting. An antiviral disinfectant-efficacy assay was developed by using viral vectors that expressed green fluorescence protein as surrogates for wild-type viruses of concern in laboratory animals. Efficacy testing revealed that most of the products were highly effective when used against viral vectors in suspension. However, when the disinfectants were challenged by buffering virus in protein or drying virus on nonporous surfaces, the hypochlorite and peroxymonosulfate products performed the best. Review of safety data sheets for the agents indicated that a peroxide-based product was considerably safer than the other products tested and that the pH of most products was not conducive to disposal down a drain. Behavioral testing of Swiss Webster, C57Bl/6, and BALB/c mice showed that the hypochlorite- and peroxide-based products were clearly aversive, given that the mice consistently avoided these products. All of these factors must be considered when choosing the appropriate disinfectant. PMID:27025810

  11. [Bioactive effectiveness of selected disinfective agents on Gram-negative bacilli isolated from hospital environment].

    PubMed

    Pancer, Katarzyna W; Laudy, Agnieszka E; Mikulak, Ewa; Gliniewicz, Aleksandra; Staniszewska, Monika; Stypułkowska-Misiurewicz, Hanna

    2004-01-01

    In our study the susceptibility (MIC) of chosen 21 strains of Gram-negative bacilli isolated in hospitals to disinfectant agents (glucoprotamine, sodium dichloroisocyanurate, potassium persulfate), the effectiveness of these disinfectants against selected bacteria and their effectiveness to biofilm forming bacteria was determined. It was found that glucoprotamine showed the highest activity to Gram-negative bacteria. Obtained MIC values for glucoprotamine (except 1 strain of S. marcescens) were 16-64 times lower that MICs for sodium dichloroisocyanurate and 4-32 times lower that MICs for potassium persulfate. The effectiveness of disinfectants containing potassium persulfate or sodium dichloroisocyanurate was 100% tested by carrier method. Glucoprotamine was ineffective against 2 out of 9 strains (18%): E. cloacae and S. marcescens. It was found that disinfectants were more effective against Gram-negative bacteria in carrier methods than for biofilm forming bacteria. 86% of bacteria growing 5 days on a catheter were resistant to working solution of disinfectant containing glucoprotamine (5200 mg/L) or potassium persulfate (4300 mg/L); 66.6% of tested bacteria were resistant to working solution of sodium dichloroisocyanurate (1795.2 mg/L). In our study the highest effectiveness to biofilm forming bacteria showed disinfectant with sodium dichloroisocyanurate, the lowest--with glucoprotamine. PMID:15810507

  12. DISINFECTION EFFICIENCY AND RESIDUAL TOXICITY OF SEVERAL WASTEWATER DISINFECTANTS. VOLUME I. GRANDVILLE, MICHIGAN

    EPA Science Inventory

    This study was conducted to determine the comparative effectiveness of chlorine, bromine chloride, and ozone as wastewater disinfectants, and to determine any residual toxicity associated with wastewater disinfection with these agents or with chlorinated wastewater which had been...

  13. DISINFECTION BY-PRODUCT FORMATION BY ALTERNATIVE DISINFECTANTS AND REMOVAL BY GRANULAR ACTIVATED CARBON

    EPA Science Inventory

    The effects of the use of the alternative disinfectants on the formation of halogenated disinfection by–products (DBPs) including total organic halide, trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, chloral hydrate, and chloropicrin, were examined along ...

  14. DISINFECTION BY-PRODUCT FORMATION BY ALTERNATIVE DISINFECTANTS AND REMOVAL BY GRANULAR ACTIVATED CARBON

    EPA Science Inventory

    The effects of the use of the alternative disinfectants on the formation of halogenated disinfection by-products (DBPS) including total organic halide, trihalomethanes, haloacetic acids, haloacentonitriles, haloketones, chloral hydrate, and chloropicrin, were examined along with ...

  15. Status report on analytical methods to support the disinfectant/disinfection by-products regulation

    SciTech Connect

    Not Available

    1992-08-01

    The U.S. EPA is developng national regulations to control disinfectants and disinfection by-products in public drinking water supplies. Twelve disinfectants and disinfection by-products are identified for possible regulation under this rule. The document summarizes the analytical methods that EPA intends to propose as compliance monitoring methods. A discussion of surrogate measurements that are being considered for inclusion in the regulation is also provided.

  16. DRINKING WATER DISINFECTION BY-PRODUCTS: WHAT IS KNOWN

    EPA Science Inventory

    Chlorine, ozone, chlorine dioxide, and chloramine are currently the major disinfectants being used to disinfect drinking water. Although the alternative disinfectants (ozone, chlorine dioxide, and chloramine) are increasing in popularity in the United States, chlorine is still us...

  17. Disinfecting Filters For Recirculated Air

    NASA Technical Reports Server (NTRS)

    Pilichi, Carmine A.

    1992-01-01

    Simple treatment disinfects air filters by killing bacteria, algae, fungi, mycobacteria, viruses, spores, and any other micro-organisms filters might harbor. Concept applied to reusable stainless-steel wire mesh filters and disposable air filters. Treatment used on filters in air-circulation systems in spacecraft, airplanes, other vehicles, and buildings to help prevent spread of colds, sore throats, and more-serious illnesses.

  18. 9 CFR 71.11 - Cresylic disinfectant as permitted disinfectant; specifications.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Cresylic disinfectant as permitted disinfectant; specifications. 71.11 Section 71.11 Animals and Animal Products ANIMAL AND PLANT HEALTH... ANIMAL PRODUCTS GENERAL PROVISIONS § 71.11 Cresylic disinfectant as permitted...

  19. 9 CFR 71.11 - Cresylic disinfectant as permitted disinfectant; specifications.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cresylic disinfectant as permitted disinfectant; specifications. 71.11 Section 71.11 Animals and Animal Products ANIMAL AND PLANT HEALTH... ANIMAL PRODUCTS GENERAL PROVISIONS § 71.11 Cresylic disinfectant as permitted...

  20. Disinfection Addition and Disinfection Changes: What It Means to the LCR

    EPA Science Inventory

    This slide presentation’s general points are: Many protective pipe scales are vey dependent on ORP, and hence, state of disinfection. Adding disinfection to anoxic systems will likely cause big chemistry changes in DS and corrosion. Changing disinfectants could cause major l...

  1. The role and fate of inorganic nitrogen species during UVA/TiO₂ disinfection.

    PubMed

    Zuo, XiaoJun; Hu, Jiangyong; Chen, MinDong

    2015-09-01

    Inorganic nitrogen species have three states including ammonia nitrogen (NH4(+)/NH3), nitrite (NO2(-)) and nitrate (NO3(-)) and are often found in the disinfection system. However, no available literature could be found on their role and fate in photocatalytic disinfection systems. In this study, batch experiments were conducted to investigate bacteria inactivation, H2O2 generated and inorganic nitrogen variation to understand the role and fate of inorganic nitrogen species during UVA/TiO2 disinfection and evaluate effects of initial pH and bacteria levels on the role and fate. NH4(+)/NH3 and NO2(-) inhibited the photocatalytic disinfection process obviously. It could be confirmed through that H2O2 yield used for pathogen inactivation was dependent on NH4(+)/NH3 and NO2(-) levels. The NH4(+)/NH3 remaining, NH4(+) remaining and NO3(-) yields in only NH4(+)/NH3 photocatalytic oxidation experiments were obviously different from the corresponding values in the photocatalytic disinfection experiments with NH4(+)/NH3, which confirmed that photocatalytic disinfection had an obvious effect on the fate of NH4(+)/NH3. However, photocatalytic disinfection had slight effects on the fate of NO2(-) and NO3(-). Escherischia coli inactivation rate was the highest in neutral solutions (Initial pH 7) while the lowest in alkaline solutions (Initial pH 8.5). The decrease of NH4(+)/NH3 in alkaline solutions was the most significant. In turn, the photocatalysis of NO2(-) was more evident in acidic solutions. E. coli inactivation was reduced with the increase of initial E. coli concentrations. The initial bacteria concentrations significantly influenced the increase of NH4(+)/NH3, NH4(+) and NO3(-), but slightly impacted the decrease of NO2(-). PMID:25989592

  2. Decontamination formulations for disinfection and sterilization

    DOEpatents

    Tucker, Mark D.; Engler, Daniel E.

    2007-09-18

    Aqueous decontamination formulations that neutralize biological pathogens for disinfection and sterilization applications. Examples of suitable applications include disinfection of food processing equipment, disinfection of areas containing livestock, mold remediation, sterilization of medical instruments and direct disinfection of food surfaces, such as beef carcasses. The formulations include at least one reactive compound, bleaching activator, inorganic base, and water. The formulations can be packaged as a two-part kit system, and can have a pH value in the range of 7-8.

  3. Inactivation of Vesicular Stomatitis Virus by Disinfectants

    PubMed Central

    Wright, Herbert S.

    1970-01-01

    Twenty-four chemical disinfectants considered to be viricidal were tested. Ten disinfectants were not viricidal for vesicular stomatitis virus within 10 min at 20 C when an LD50 titer of 108.5 virus units per 0.1 ml were to be inactivated. Quantitative inactivation experiments were done with acid, alkaline, and a substituted phenolic disinfectant to determine the kinetics of the virus inactivation. Substituted phenolic disinfectants, halogens, and cresylic and hydrochloric acids were viricidal. Basic compounds such as lye and sodium metasilicate were not viricidal. PMID:4313317

  4. A survey of the methods of disinfection of dental impressions used in dental hospitals in the United Kingdom.

    PubMed

    Blair, F M; Wassell, R W

    1996-05-25

    The potential for cross-infection from microbial contaminated dental impressions has long been recognised. This study set out to investigate impression decontamination procedures currently used in UK dental hospitals (1995) and to see how these may have changed since a previous survey, carried out in 1988. A variety of disinfection solutions and regimes were highlighted both within and between dental hospitals. Several of the disinfecting solutions currently being used have not been specifically tested for efficacy with impression materials. The laboratories were asked to highlight any adverse reactions. Five laboratories reported that some alginates resulted in casts with poor surface properties when immersed in hypochlorite (0.1 and 1%), sodium dichloroisocyanurate, and 2% glutaraldehyde solutions. This paper highlights that there is no universally recognised impression disinfection/sterilisation protocol. It is recommended that all impressions should at least undergo a disinfecting procedure by immersion in 1% sodium hypochlorite for a minimum of 10 minutes. PMID:8652299

  5. Disinfection associated spoilage of high water content ionic matrix hydrogels.

    PubMed

    Sack, R A; Harvey, H; Nunes, I

    1989-01-01

    Chemical analysis was carried out on clinically obtained hazy white hydrogel lenses that had been exposed to hydrogen peroxide disinfection. Analysis revealed that hazing was a surface phenomenon limited to high water content ionic matrix hydrogels (type IV), the type associated with the deposition of large amounts of lysozyme. We subjected unworn lenses to cycling studies involving doping in a variable artificial tear solution followed by exposure to disinfectant; this allowed us to duplicate the clinical situation and to derive a mechanism for this phenomenon. Hazing proved independent of the presence of hydrogen peroxide but dependent on the interaction of lens-bound lysozyme and stannate anion, the latter derived from sodium stannate present in the disinfectant as a stabilizing agent. Hazing is restricted to the type IV hydrogels because only these polymers have a sufficient number of anionic binding sites and are of sufficient porosity to allow the penetration and binding of a thick layer of lysozyme. Lysozyme is essential to hazing. No other tear protein is small enough to penetrate the hydrogel matrix or basic enough to have a marked affinity for the lens and to provide binding sites for stannate anion. These findings highlight the unique vulnerability of the type IV hydrogel to interaction with trace or transient ionic constituents in tears and lens care solutions. PMID:2720948

  6. Detection of regulated disinfection by-products in cheeses.

    PubMed

    Cardador, Maria Jose; Gallego, Mercedes; Cabezas, Lourdes; Fernández-Salguero, Jose

    2016-08-01

    Cheese can contain regulated disinfection by-products (DBPs), mainly through contact with brine solutions prepared in disinfected water or sanitisers used to clean all contact surfaces, such as processing equipment and tanks. This study has focused on the possible presence of up to 10 trihalomethanes (THMs) and 13 haloacetic acids (HAAs) in a wide range of European cheeses. The study shows that 2 THMs, (in particular trichloromethane) and 3 HAAs (in particular dichloroacetic acid) can be found at μg/kg levels in the 56 cheeses analysed. Of the two types of DBPs, HAAs were generally present at higher concentrations, due to their hydrophilic and non-volatile nature. Despite their different nature (THMs are lipophilic), both of them have an affinity for fatty cheeses, increasing their concentrations as the percentage of water decreased because the DBPs were concentrated in the aqueous phase of the cheeses. PMID:26988506

  7. Disinfecting endoscopes: how not to transmit Mycobacterium tuberculosis by bronchoscopy.

    PubMed Central

    Leers, W D

    1980-01-01

    Mycobacterium tuberculosis was cultured from the bronchial washings of two patients who underwent bronchoscopy consecutively with the same bronchoscope. Active pulmonary tuberculosis was later confirmed in the first patient, whereas the second patient had clinical and serologic evidence of infection with respiratory syncytial virus. The bronchoscope had been cleaned with an iodophor disinfectant, which had not destroyed the tubercle bacilli. The agent recommended for chemical disinfection of fibreoptic bronchoscopes is 2% glutaraldehyde solution; the instrument should be immersed in it for 10 to 30 minutes. Five hours' exposure to ethylene oxide is recommended for sterilization of instruments. These procedures must be preceded by adequate mechanical cleaning. Then transmission of pathogenic organisms during endoscopy, which can result in nosocomial disease, misdiagnosis or inappropriate treatment, will be avoided. Images FIG. 1 FIG. 2 FIG. 3 PMID:6790150

  8. Disinfection of Dental Unit Water Line Using Aloe Vera: In Vitro Study

    PubMed Central

    Pareek, Sonia; Nagaraj, Anup; Sharma, Prateek; Walia, Satinder; Naidu, Shravani; Yousuf, Asif

    2013-01-01

    Context. Dental unit waterlines may be heavily contaminated with microorganisms and are a potential source of infection for both practicing staff and immunocompromised patients particularly. Contamination of dental unit water lines could be inhibited with the use of disinfectants. The present study investigates the effect of aloe-vera-based disinfectant in reducing the microbial growth in dental unit water lines (DUWLs). Aims. To compare the efficacy of aloe vera, hydrogen peroxide (H2O2), and 5% sodium hypochlorite (NaOCl) in controlling microbial contamination of DUWLs. Materials and Methods. After obtaining baseline water samples, the dental unit waterlines were treated with aloe vera, 10% hydrogen peroxide, and 5% sodium hypochlorite. Each of the three disinfectants was used in increasing concentrations and their inhibiting effect was compared. Water samples were analyzed for microbiological quality by the total viable count (TVC) method. Statistical Analysis Used. SPSS 16. Results. There was significant reduction in mean CFU/ml when treated with disinfectants each for a period of one week. Aloe-vera solution was found to be the most effective in reducing the microbial colonies. Conclusions. Improving the water quality from dental unit water lines is of considerable importance; chemical-based disinfectants can be replaced with herbal disinfectants for treating microbial contamination in dental unit waterlines. PMID:24089615

  9. Entrapped cell system for decentralized hospital wastewater treatment: inhibitory effect of disinfectants.

    PubMed

    Siripattanakul-Ratpukdi, Sumana

    2012-01-01

    This study aims to improve decentralized hospital wastewater treatment inhibited by disinfectants by using calcium alginate cell entrapment technique. The effects of disinfectant types (glutaraldehyde, povidone iodine (PI) and a potassium hydroxide solution) and disinfectant concentrations, cell entrapment conditions (cell-to-matrix ratios) and cell loadings were investigated. The batch experiments were conducted using synthetic wastewater with initial chemical oxygen demand (COD) of approximately 370 mg/L and acclimated activated sludge. Among three disinfectants, PI substantially affected the wastewater treatment efficiency (inhibition of 40%) while other disinfectants exhibited inhibition effects of less than 9%. The results also indicated that the entrapped cells obviously performed better than the free cells. The cell-to-matrix ratio of 1:20 (v/v) provided the highest treatment efficiency of 86% (inhibition of 9%) while the free cell system had inhibition of 47%. The system at the entrapped cell loading of 2000 mg/L performed the highest COD removal of 62% for ten-cycle sequencing batch operation. A scanning electron microscope image provided information on entrapped cell structure subjected to the disinfectant. PMID:23393973

  10. The Role of Combination Techniques in Maximizing the Utility of Precipitation Estimates from Several Multi-Purpose Remote-Sensing Systems

    NASA Technical Reports Server (NTRS)

    Huffman, George J.; Adler, Robert F.; Bolvin, David T.; Curtis, Scott; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Multi-purpose remote-sensing products from various satellites have proved crucial in developing global estimates of precipitation. Examples of these products include low-earth-orbit and geosynchronous-orbit infrared (leo- and geo-IR), Outgoing Longwave Radiation (OLR), Television Infrared Operational Satellite (TIROS) Operational Vertical Sounder (TOVS) data, and passive microwave data such as that from the Special Sensor Microwave/ Imager (SSM/I). Each of these datasets has served as the basis for at least one useful quasi-global precipitation estimation algorithm; however, the quality of estimates varies tremendously among the algorithms for the different climatic regions around the globe.

  11. Spin Forming of an Aluminum 2219-T6 Aft Bulkhead for the Orion Multi-Purpose Crew Vehicle: Phase II Supplemental Report

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Squire, Michael D.; Domack, Marcia S.; Hoffman, Eric K.

    2015-01-01

    The principal focus of this project was to assist the Orion Multi-Purpose Crew Vehicle (MPCV) Program in developing a spin forming fabrication process for manufacture of the aft bulkhead of the pressure vessel. The spin forming process will enable a single piece aluminum (Al) 2219 aft bulkhead which will eliminate the current multiple piece welded construction, simplify fabrication, and lead to an enhanced design that will reduce vehicle weight by eliminating welds. Phase I of this assessment explored spin forming the single-piece forward pressure vessel bulkhead from aluminum-lithium 2195.

  12. 40 CFR 141.72 - Disinfection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for Giardia lamblia cysts and viruses. If a system uses a disinfectant other than chlorine, the system...) The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, as specified in § 141.74 (a)(2) and (b)(6), cannot be...

  13. 40 CFR 141.72 - Disinfection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for Giardia lamblia cysts and viruses. If a system uses a disinfectant other than chlorine, the system...) The residual disinfectant concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, as specified in § 141.74 (a)(2) and (b)(6), cannot be...

  14. MUTAGENICITY OF DRINKING WATER FOLLOWING DISINFECTION

    EPA Science Inventory

    Many drinking water utilities in the USA are considering alternatives to chlorine for disinfection in order to comply with federal regulations regarding disinfection by-products. An evaluation is thus needed of the potential risks associated with the use of alternative disinfecta...

  15. CHLORINE DISINFECTION STUDIES OF ENCEPHALITOZOON (SEPTATA) INTESTINALIS

    EPA Science Inventory

    A reproducible standardized assay was designed to determine two infective doses for E.intestinalis, the TCID50 and the MID. These doses can be used to assess the potential effectiveness of chlorine disinfection and can also be used to assess other disinfection parameters and ant...

  16. Disinfection: is it time to reconsider Spaulding?

    PubMed

    McDonnell, G; Burke, P

    2011-07-01

    The Spaulding classification, originally proposed in 1957, is a widely used system for matching the disinfection and sterilization of surfaces, particularly those of re-usable medical/surgical devices, with available processes. It presents a ranking, from simple disinfection through to sterilization, that should be considered in the reprocessing of devices, based on the risks associated with their use, ranging from 'critical' (presenting a high risk), through 'semi-critical' to 'non-critical' (presenting a low risk). The different levels of disinfection are based on demonstrating antimicrobial activity against established marker micro-organisms representing a range of pathogens. Although this classification system is probably as valid today as it was in 1957, the understanding of microbiology and micro-organisms has changed. This article discusses some examples of disinfection studies with viruses, bacteria, protozoa and prions that challenge the current definitions and expectations of high-, intermediate- and low-level disinfection. In many of these examples, the test micro-organisms demonstrate atypical tolerance or resistance profiles to disinfection processes. In addition to laboratory-based studies, there is now clinical evidence for at least some of these micro-organisms that biocide resistance can lead to infection outbreaks due to unexpected disinfection failure. These reports should encourage the reader to challenge current dogma, and reconsider the expectations of disinfection and sterilization practices. PMID:21664533

  17. Silver disinfection in water distribution systems

    NASA Astrophysics Data System (ADS)

    Silvestry Rodriguez, Nadia

    Silver was evaluated as disinfectant to maintain water quality in water distribution system. It was used to inhibit growth of two opportunistic bacteria in planktonik form and in biofilm formation in Robbins devices with stainless steel and PVC surfaces. The results of this work show that silver is a potential secondary disinfectant to be used in water distribution systems.

  18. ULTRAVIOLET DISINFECTION STUDIES WITH CCL LISTED MICROORGANISMS

    EPA Science Inventory

    Resistance to ultraviolet (UV) disinfection is an essential aspect regarding all microbial groups listed on the CCL. The U.S. drinking water industry is interested in including UV light treatment as an amendment to conventional treatment for disinfecting water supplies. UV disi...

  19. Ultraviolet (UV) Disinfection for Drinking Water Systems

    EPA Science Inventory

    UV disinfection is an effective process for inactivating many microbial pathogens in water with potential to serve as stand-alone treatment or in combination with other disinfectants. USEPA provided guidance on the validation of UV reactors nearly a decade ago. Since then, lesson...

  20. Disinfection of Bacillus spores with acidified nitrite.

    PubMed

    Szabo, Jeffrey G; Adcock, Noreen J; Rice, Eugene W

    2014-10-01

    Disinfecting water generated from a bioterrorism contamination event will require large amounts of disinfectant since the volume of water flushed from a drinking water distribution system or wash water collected from a contaminated outdoor area can accumulate quickly. Commonly used disinfectants may be unavailable in the necessary amounts, so evaluation of alternative disinfectants is needed. This study focuses on disinfection of Bacillus spores in water using acidified nitrite. The effect of varying pH (2 or 3), temperature (5°C or 24°C), nitrite concentration (0.01 or 0.1M), buffer (Butterfields or Phosphate Buffered Saline, PBS) and Bacillus species (B. globigii and B. anthracis Sterne) was evaluated. B. globigii was more resistant to disinfection under all water quality conditions. Disinfection was more effective for B. globigii and B. anthracis Sterne at 0.1M nitrite, pH 2, and 24°C. Disinfection of B. anthracis Sterne was enhanced in low ionic strength Butterfields buffer compared to PBS. PMID:25065806

  1. 9 CFR 71.10 - Permitted disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... § 71.10 Permitted disinfectants. (a) Disinfectants permitted for use on cars, boats, and other vehicles... least 4 fluid ounces to 1 gallon of water. (2) Liquefied phenol (U.S.P. strength 87 percent phenol) in... general use, may be used for the purpose of this part in accordance with directions on the labels...

  2. 9 CFR 71.10 - Permitted disinfectants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 71.10 Permitted disinfectants. (a) Disinfectants permitted for use on cars, boats, and other vehicles... least 4 fluid ounces to 1 gallon of water. (2) Liquefied phenol (U.S.P. strength 87 percent phenol) in... general use, may be used for the purpose of this part in accordance with directions on the labels...

  3. 9 CFR 71.10 - Permitted disinfectants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 71.10 Permitted disinfectants. (a) Disinfectants permitted for use on cars, boats, and other vehicles... least 4 fluid ounces to 1 gallon of water. (2) Liquefied phenol (U.S.P. strength 87 percent phenol) in... general use, may be used for the purpose of this part in accordance with directions on the labels...

  4. 9 CFR 71.10 - Permitted disinfectants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... § 71.10 Permitted disinfectants. (a) Disinfectants permitted for use on cars, boats, and other vehicles... least 4 fluid ounces to 1 gallon of water. (2) Liquefied phenol (U.S.P. strength 87 percent phenol) in... general use, may be used for the purpose of this part in accordance with directions on the labels...

  5. 9 CFR 71.10 - Permitted disinfectants.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... § 71.10 Permitted disinfectants. (a) Disinfectants permitted for use on cars, boats, and other vehicles... least 4 fluid ounces to 1 gallon of water. (2) Liquefied phenol (U.S.P. strength 87 percent phenol) in... general use, may be used for the purpose of this part in accordance with directions on the labels...

  6. Microwave discharge electrodeless lamps (MDEL). V. Microwave-assisted photolytic disinfection of Bacillus subtilis in simulated electroplating wash wastewaters.

    PubMed

    Horikoshi, Satoshi; Tsuchida, Akihiro; Abe, Masahiko; Ohba, Naoki; Uchida, Masayoshi; Serpone, Nick

    2010-01-01

    This short article examines the microwave-assisted photolytic disinfection of aqueous solutions contaminated by Bacillus subtilis microorganisms using UV and vacuum-UV radiation emitted from a microwave discharge electrodeless lamp (MDEL), a device containing a Hg/Ar gas-fill that was proposed recently for use in Advanced Oxidation Processes (AOPs). Results of the disinfection are compared with those obtained from UV radiation emitted by a low-pressure electrode Hg lamp and by an excimer lamp. Also examined is the disinfection of B. subtilis aqueous media that contained Au3+ or Ni2+ ions, species often found in the treatment of electroplating wash wastewaters. PMID:21721320

  7. Comparative analysis of existing disinfection models.

    PubMed

    Andrianarison, T; Jupsin, H; Ouali, A; Vasel, J-L

    2010-01-01

    For a long time Marais's model has been the main tool for disinfection prediction in waste stabilization ponds (WSPs), although various authors have developed other disinfection models. Some ten other empirical models have been listed over the past fifteen years. Unfortunately, their predictions of disinfection in a given pond are very different. The existing models are too empirical to give reliable predictions: often their explanatory variables were chosen arbitrarily. In this work, we try to demonstrate that if influent variables have daily variations, the use of their average values in simulations may overestimate the disinfection effect. New methods are thus needed to provide better fittings of the models. Better knowledge of the mechanisms involved is needed to improve disinfection models. PMID:20182074

  8. Chemical Disinfection of Holding-Tank Sewage

    PubMed Central

    Sobsey, Mark D.; Wallis, Craig; Melnick, Joseph L.

    1974-01-01

    A number of chemical disinfectants were evaluated for their bactericidal and virucidal effectiveness in holding-tank sewage. It was found that the disinfection efficiencies of formaldehyde, benzalkonium chloride, cetylpyridinium chloride, and methylene blue were markedly improved if the pH of the sewage was raised from 8.0 to 10.5. When formaldehyde, benzalkonium chloride, and methylene blue were tested with either 2-week holding times with no sewage additions or 10-day holding times with daily sewage additions, disinfection effectiveness was maintained as long as the sewage pH was kept at 10.5 and the disinfectant concentration was kept at 100 mg/liter or more. Calcium hypochlorite, zinc sulfate, and phenol were found to be relatively ineffective disinfectants for holding-tank sewage. PMID:4374122

  9. Chemical disinfection of holding-tank sewage.

    PubMed

    Sobsey, M D; Wallis, C; Melnick, J L

    1974-11-01

    A number of chemical disinfectants were evaluated for their bactericidal and virucidal effectiveness in holding-tank sewage. It was found that the disinfection efficiencies of formaldehyde, benzalkonium chloride, cetylpyridinium chloride, and methylene blue were markedly improved if the pH of the sewage was raised from 8.0 to 10.5. When formaldehyde, benzalkonium chloride, and methylene blue were tested with either 2-week holding times with no sewage additions or 10-day holding times with daily sewage additions, disinfection effectiveness was maintained as long as the sewage pH was kept at 10.5 and the disinfectant concentration was kept at 100 mg/liter or more. Calcium hypochlorite, zinc sulfate, and phenol were found to be relatively ineffective disinfectants for holding-tank sewage. PMID:4374122

  10. Quaternary Ammonium Disinfectant Issues Encountered in an Environmental Services Department.

    PubMed

    Boyce, John M; Sullivan, Linda; Booker, Arica; Baker, James

    2016-03-01

    We identified several factors affecting the use of quaternary ammonium-based (Quat) disinfectant in our facility. Microfiber wipers, cotton towels, and 1 of 2 types of disposable wipes soaked in a Quat disinfectant revealed significant binding of the disinfectant. Concentrations of Quat delivered by automated disinfectant dispensers varied widely. PMID:26821275

  11. The question of pathogen quantification in disinfected graywater.

    PubMed

    Benami, Maya; Gillor, Osnat; Gross, Amit

    2015-02-15

    Graywater (GW) reuse for irrigation is recognized as a sustainable solution for water conservation. One of the major impediments to GW reuse is the presence of pathogenic microorganisms. This study monitored three similar on-site GW treatment systems bi-monthly over the course of a year to compare the presence of pathogens and indicators in raw, biologically treated, and biologically treated and disinfected [by chlorine and ultraviolet light (UV)] GW. The systems were designed to allow the testing of the same batch (collection) of water as it passed through the treatment chain. The samples were analyzed using standard culture-dependent methods and the data were compared to culture-independent DNA-based methods. Results suggested that the presence and abundance of fecal coliforms, Escherichia coli, Salmonella enterica, Enterococcus spp., Staphylococcus aureus and Pseudomonas aeruginosa differ among the various GW streams (e.g. raw, biologically treated, and disinfected). The culture-dependent analyses suggested that both chlorine and UV inactivate most of the bacteria tested in the biologically treated GW, albeit at different efficiencies. Conversely, the DNA-based analyses indicated no significant differences in pathogenic bacterial abundance between the biologically treated GW with or without disinfection. To better understand the discrepancies between the results, we repeated the analysis in the laboratory under controlled conditions using Enterococcus faecalis as a model bacterium and obtained similar results. We suggest that disinfection of biologically treated GW with chlorine or UV is effective for treating pathogens, but that the inactivation efficiency cannot be estimated by DNA-based qPCR. PMID:25437766

  12. Comparison of three different sterilization and disinfection methods on orthodontic markers

    PubMed Central

    Omidkhoda, Maryam; Rashed, Roozbeh; Bagheri, Zahra; Ghazvini, Kiarash; Shafaee, Hooman

    2016-01-01

    Background: Marking pencils which are frequently used in orthodontics may cause microbial contamination. The purpose of this study was to evaluate and compare the effectiveness of three disinfection and sterilization methods (autoclave, glutaraldehyde solution, and Deconex spray) on orthodontic markers. Materials and Methods: One hundred and twenty orthodontic markers were divided into four groups each 30 pencils: One control group and three groups for three different disinfection/sterilization methods. To evaluate the effectiveness of these methods, pencils were initially contaminated by common pathogen by immersing the pencils in a suspension containing 1.5 × 108 CFU/ml organisms. Then, the pencils were subjected to corresponding disinfection/sterilization methods, and the number of remaining microorganisms was calculated and compared with control group. Results: In the control group, the mean number of Escherichia coli was significantly higher than the other two microorganisms (P = 0.01, P = 0.031). However, the mean numbers of Staphylococcus aureus and Candida albicans were not significantly different (P = 0.1). After sterilization with autoclave and glutaraldehyde, no microbial growth was observed, whereas after disinfection with Deconx spray some colonies of microorganisms still could be observed. Conclusion: Autoclaving and glutaraldehyde solution are the best methods for disinfecting orthodontic markers. PMID:26998472

  13. Microbial resistance to disinfectants: mechanisms and significance

    SciTech Connect

    Hoff, J.C.; Akin, E.W.

    1986-11-01

    Drinking water disinfection provides the final barrier to transmission of a wide variety of potentially waterborne infectious agents including pathogenic bacteria, viruses, and protozoa. These agents differ greatly in their innate resistance to inactivation by disinfectants, ranging from extremely sensitive bacteria to highly resistant protozoan cysts. The close similarity between microorganism inactivation rates and the kinetics of chemical reactions has long been recognized. Ideally, under carefully controlled conditions, microorganism inactivation rates simulate first-order chemical reaction rates, making it possible to predict the effectiveness of disinfection under specific conditions. In practice, changes in relative resistance and deviations from first-order kinetics are caused by a number of factors, including microbial growth conditions, aggregation, and association with particulate materials. The net effect of all these factors is a reduction in the effectiveness and predictability of disinfection processes. To ensure effective pathogen control, disinfectant concentrations and contact times greater than experimentally determined values may be required. Of the factors causing enhanced disinfection resistance, protection by association with particulate matter is the most significant. Therefore, removal of particulate matter is an important step in increasing the effectiveness of disinfection processes.

  14. Microbial resistance to disinfectants: mechanisms and significance.

    PubMed Central

    Hoff, J C; Akin, E W

    1986-01-01

    Drinking water disinfection provides the final barrier to transmission of a wide variety of potentially waterborne infectious agents including pathogenic bacteria, viruses, and protozoa. These agents differ greatly in their innate resistance to inactivation by disinfectants, ranging from extremely sensitive bacteria to highly resistant protozoan cysts. The close similarity between microorganism inactivation rates and the kinetics of chemical reactions has long been recognized. Ideally, under carefully controlled conditions, microorganism inactivation rates simulate first-order chemical reaction rates, making it possible to predict the effectiveness of disinfection under specific conditions. In practice, changes in relative resistance and deviations from first-order kinetics are caused by a number of factors, including microbial growth conditions, aggregation, and association with particulate materials. The net effect of all these factors is a reduction in the effectiveness and predictability of disinfection processes. To ensure effective pathogen control, disinfectant concentrations and contact times greater than experimentally determined values may be required. Of the factors causing enhanced disinfection resistance, protection by association with particulate matter is the most significant. Therefore, removal of particulate matter is an important step in increasing the effectiveness of disinfection processes. Images FIGURE 6. PMID:3816738

  15. [Disinfection efficiency for outlet water from biological activated carbon process by different disinfecting modes].

    PubMed

    Zhi, Xing-hua; Bai, Xiao-hui; Meng, Ming-qun

    2011-05-01

    Lab-scale tests were designed to treat the leak of bacteria from BAC process. Water samples from outlet of BAC pool in Xujing Waterworks in Shanghai were disinfected by NaClO and NH2Cl disinfectant to compare the disinfection efficiency. Heterotrophic bacteria in disinfected water were cultivated and counted and halo hydrocarbons were detected by GC. To keep the disinfecting efficacy [lg(N0/N)] over 2 under the water temperature of 30 degrees C, NaClO should have an initial concentration more than 1.84 mg/L total chlorine and contact with bacteria for about 30 minutes. As to NH2Cl disinfection, the initial concentration should be more than 2.20 mg/L total chlorine and contacting time should be prolonged to about 90 minutes. The production of CHCl3 ranged from 4.97 to 7.10 microg/L and CCl4 ranged from 0.01 to 0.71 microg/L in NaClO disinfection tests with a initial disinfecting concentration in the range of 1.53-2.42 mg/L total chlorine values. In NH2Cl disinfecting tests, CHCl3 ranged from 4.43 to 5.55 microg/L and CCl4 ranged from 0.01 to 0.64 microg/L when initial disinfecting concentration limited in the range of 2.10-2.86 mg/L total chlorine values. All was below the state drinking water standard. The results showed that the disinfection process can be divided into fast step and slow step. NaCl0 has higher disinfecting efficiency on bacteria than NH2Cl, but neither can reach 100% effectivity. Meanwhile the risk of producing halo hydrocarbon over standard was proved to be negligible. PMID:21780589

  16. Implications of changing water cycle for the performance and yield characteristics of the multi-purpose Beas Reservoir in India

    NASA Astrophysics Data System (ADS)

    Adeloye, A. J.; Ojha, C. S.; Soundharajan, B.; Remesan, R.

    2013-12-01

    There is considerable change in both the spatial and temporal patterns of monsoon rainfall in India, with implications for water resources availability and security. 'Mitigating the Impacts of Climate Change on India Agriculture' (MICCI) is one of five on-going scientific efforts being sponsored as part of the UK-NERC/India-MOES Changing Water Cycle (South Asia) initiative to further the understanding of the problem and proffer solutions that are robust and effective. This paper focuses on assessing the implications of projected climate change on the yield and performance characteristics of the Pong Reservoir on the Beas River, Himachal Pradesh, India. The Pong serves both hydropower and irrigation needs and is therefore strategic for the socio-economic well-being of the region as well as sustaining the livelihoods of millions of farmers that rely on it for irrigation. Simulated baseline and climate-change perturbed hydro-climate scenarios developed as part of a companion Work Package of MICCI formed the basis of the analysis. For both of these scenarios, reservoir analyses were carried out using the Sequent Peak Algorithm (SPA) and Pong's existing level of releases to derive rule curves for the reservoir. These rule curves then formed the basis of further reservoir behaviour simulations in WEAP and the resulting performance of the reservoir was summarised in terms of reliability, resilience, vulnerability and sustainability. The whole exercise was implemented within a Monte Carlo framework for the benefit of characterising the variability in the assessments. The results show that the rule curves developed using future hydro-climate are significantly changed from the baseline in that higher storages will be required to be maintained in the Pong in the future to achieve reliable performance. As far as the overall performance of the reservoir is concerned, future reliability (both time-based and volume-based) is not significantly different from the baseline, provided

  17. [Virucidal activity of disinfectants. Influence of the serum protein upon the virucidal activity of disinfectants].

    PubMed

    Noda, M; Matsuda, S; Kobayashi, M

    2000-08-01

    Five disinfectants were tested for virucidal activity on three DNA viruses and three RNA viruses in the presence or absence of serum protein. Disinfectants of the aldehyde and halogen groups had a virucidal activity on human herpes virus, bovine rhabdo virus, human immunodeficiency virus, human adeno virus, porcine parvo virus, and polio virus. Disinfectants of the invert and amphoteric soap groups, and biganide group had a destructive effect on RNA and DNA viruses possessing an envelope. The presence of serum protein exerted great influence upon the virucidal activity of disinfectants of the invert and amphoteric soap groups. PMID:11019515

  18. Dynamic mechanical thermal analysis of maxillofacial prosthetic elastomers: the effect of different disinfecting aging procedures.

    PubMed

    Eleni, Panagiota N; Krokida, Magdalini K; Polyzois, Gregory L; Gettleman, Lawrence

    2014-05-01

    In this study, dynamic mechanical thermal analysis was used to evaluate the changes that occurred in maxillofacial elastomers subjected to different disinfecting regimens. A commercial polydimethyl siloxane (PDMS) and an experimental chlorinated polyethylene (CPE) were treated with different disinfection procedures for a period that simulates 1 year of clinical service: microwave exposure (D1), hypochlorite solution (D2), neutral soap (D3), and a commercial disinfecting solution (D4). A fifth group was kept in dark storage as control. Dynamic mechanical thermal analysis tests operated in a fixed frequency (1 Hz) over a range of temperatures (-130°C to 20°C for PDMS, -60°C to 120°C for CPE). Loss modulus (G″), storage modulus (G'), and loss factor (tanδ) were recorded as a function of temperature. The obtained glass transition temperature (Tg) values were subjected to statistical analysis. Dynamic mechanical thermal analysis revealed changes in Tg values for both materials, which reflect the possible changes in their chemical and physical structure, after different disinfection procedures. The PDMS and CPE samples seem to have less dense structure maybe because of chain scission reaction that probably occurred during the disinfection procedures. According to statistical analysis, Tg values presented significant changes from the control samples among the different materials and disinfecting procedures. Microwave exposure and hypochlorite solution affect CPE significantly, whereas PDMS exhibited significant changes after being treated with a commercial antimicrobial agent, concerning changes that occurred in Tg. In all cases, Tg values were decreased compared with the untreated samples, which were stiffer, presenting higher Tg and G' values. PMID:24799103

  19. Use of Clinical UV Chamber to Disinfect Dental Impressions: A Comparative Study

    PubMed Central

    Sharma, Sakshi; Kumar, Varun; Gupta, Neelu

    2015-01-01

    Introduction Dental impressions are potential source of infection in a prosthodontic practice. Risk of transmission of infection through saliva, blood etc is considered as hazard for both dentist as well as dental auxiliary staff. A number of methods are currently employed for disinfecting the impressions which are technique sensitive and time consuming. This study focuses on disinfecting impression using dental UV chamber which is commonly employed for storing sterilized instruments. Aim The aim of this invitro study was to evaluate the use of clinical UV chamber to disinfect various impression materials at different time intervals and its comparison with 2% glutaraldehyde using standard immersion technique. Materials and Methods Total sample size of 180 specimens was taken from three different impression materials. The impressions were made from 30 dentulous subjects. A total of ten impressions were made for each impression material i.e. alginate, addition silicone and polyether impression material. Six punch samples were taken from each impression. Out of 6 punch sample, one was kept as control, second was disinfected by immersing in freshly prepared 2% glutaraldehyde solution for 10 minutes and remaining four were exposed to UV rays for 3 minutes, 6 minutes, 10 minutes and 15 minutes using dental UV chamber. Amount of disinfection achieved was evaluated by counting the colonies over the culture plates with the help of digital colony. Results The results showed that the mean CFUs for alginate were found to be i.e. 11797.40 ± 5989.73 (mean ± SD). The mean CFUs for addition silicone impression material was found 7095.40 with a standard deviation of 4268.83 and the mean CFUs for polyether impression material was found to be 2168.92 ± 1676 (mean ± SD). Conclusion For alginate and addition silicone impression material, disinfection was achieved on exposure to UV rays for a period of 10 minutes. However, for polyether impression material 3 minutes of exposure to

  20. SU-E-J-47: Development of a High-Precision, Image-Guided Radiotherapy, Multi- Purpose Radiation Isocenter Quality-Assurance Calibration and Checking System

    SciTech Connect

    Liu, C; Yan, G; Helmig, R; Lebron, S; Kahler, D

    2014-06-01

    Purpose: To develop a system that can define the radiation isocenter and correlate this information with couch coordinates, laser alignment, optical distance indicator (ODI) settings, optical tracking system (OTS) calibrations, and mechanical isocenter walkout. Methods: Our team developed a multi-adapter, multi-purpose quality assurance (QA) and calibration device that uses an electronic portal imaging device (EPID) and in-house image-processing software to define the radiation isocenter, thereby allowing linear accelerator (Linac) components to be verified and calibrated. Motivated by the concept that each Linac component related to patient setup for image-guided radiotherapy based on cone-beam CT should be calibrated with respect to the radiation isocenter, we designed multiple concentric adapters of various materials and shapes to meet the needs of MV and KV radiation isocenter definition, laser alignment, and OTS calibration. The phantom's ability to accurately define the radiation isocenter was validated on 4 Elekta Linacs using a commercial ball bearing (BB) phantom as a reference. Radiation isocenter walkout and the accuracy of couch coordinates, ODI, and OTS were then quantified with the device. Results: The device was able to define the radiation isocenter within 0.3 mm. Radiation isocenter walkout was within ±1 mm at 4 cardinal angles. By switching adapters, we identified that the accuracy of the couch position digital readout, ODI, OTS, and mechanical isocenter walkout was within sub-mm. Conclusion: This multi-adapter, multi-purpose isocenter phantom can be used to accurately define the radiation isocenter and represents a potential paradigm shift in Linac QA. Moreover, multiple concentric adapters allowed for sub-mm accuracy for the other relevant components. This intuitive and user-friendly design is currently patent pending.

  1. Wastewater Disinfectants: Many Called--Few Chosen

    ERIC Educational Resources Information Center

    Smith, James W.

    1978-01-01

    Gives a comparative study of disinfectants used to rid wastewater of pathogens. Concentrates on the effects of chlorine and ozone, with some mention of ultra-violet irradiation, bromine chloride, and chlorine dioxide. (MA)

  2. ALTERNATIVE DISINFECTANTS FOR DRINKING WATER TREATMENT

    EPA Science Inventory

    During a one-year study at Jefferson Parish, Louisiana the chemical, microbiological, and mutagenic effects of using the major drinking water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. ests were performed on samples collected from various treatm...

  3. Environmental Cleaning and Disinfecting for MRSA

    MedlinePlus

    ... stores and other retail stores. Check the disinfectant product’s label on the back of the container. Most, if ... check for an EPA registration number on the product’s label to confirm that it is registered). How should ...

  4. Disinfection, sterilization, and antisepsis: An overview.

    PubMed

    Rutala, William A; Weber, David J

    2016-05-01

    All invasive procedures involve contact by a medical device or surgical instrument with a patient's sterile tissue or mucous membranes. The level of disinfection or sterilization is dependent on the intended use of the object: critical (items that contact sterile tissue such as surgical instruments), semicritical (items that contact mucous membrane such as endoscopes), and noncritical (devices that contact only intact skin such as stethoscopes) items require sterilization, high-level disinfection and low-level disinfection, respectively. Cleaning must always precede high-level disinfection and sterilization. Antiseptics are essential to infection prevention as part of a hand hygiene program as well as several other uses such as surgical hand antisepsis and pre-operative skin preparation. PMID:27131128

  5. UV disinfection for onsite sand filter effluent

    SciTech Connect

    Lowery, J.D.; Romatzick, S.

    1982-05-01

    The technical and economic feasibility of using ultraviolet (uv) light as a viable alternative to chlorine as the required disinfectant for onsite sand filter effluents discharged to surface waters in Maine was determined. To obtain a reliable cross section of performance for sand filters in Maine, 74 filters were selected for an effluent characterization program. The effluent characterization study allowed general conclusions to be made with regard to the potential of uv disinfection. A simple suspended lamp uv disinfection unit was designed, constructed, and tested in the laboratory and in the field. The efficiency of the uv disinfection unit was determined through field testing at 10 of the 74 sand filter sites used in the effluent characterization program.

  6. DISINFECTION BYPRODUCTS AND HUMAN SEMEN QUALITY

    EPA Science Inventory

    This project, also called the Healthy Men Study will examine potential associations between human exposure to drinking water disinfection byproducts, particularly haloacetic acids (HAAs) and trihalomethanes (THMs), and male reproductive health as indicated by semen quality. Sinc...

  7. ALTERNATIVE DISINFECTION FOR DRINKING WATER TREATMENT

    EPA Science Inventory

    During a one-yr study at Jefferson Parish, La., the chemical, microbiological, and mutagenic effects os using the major drinkgin water disinfectants (chlorine, chlorine dioxide, chloramine, ozone) were evaluated. Tests were performed on samples collected from various treatment s...

  8. Application of disinfectants in poultry hatcheries.

    PubMed

    Samberg, Y; Meroz, M

    1995-06-01

    Veterinary control and routine sanitary procedures in commercial poultry hatcheries should include the following: choice of a suitable geographical location to ensure an isolated site; proper hatchery design with separation of major operations; one-way flow of work within the hatchery; adequate ventilation of each room; routine cleaning and disinfection; formaldehyde fumigation or alternative method for disinfection of eggs, equipment and incubators; a routine programme for monitoring microbial contamination levels within the hatchery. PMID:7579636

  9. Disinfection practices in intravenous drug administration.

    PubMed

    Helder, Onno K; Kornelisse, René F; Reiss, Irwin K M; Ista, Erwin

    2016-06-01

    The aim of the study was to determine the effectiveness of a feedback intervention on adherence to disinfection procedures during intravenous medication preparation and administration. We found that full adherence to the protocols significantly improved from 7.3% to 21.5% (P < .001) regarding medication preparation and from 7.9% to 15.5% (P = .012) regarding medication administration. However, disinfection practices still need improvement. PMID:26899528

  10. Residual Structure of Streptococcus mutans Biofilm following Complete Disinfection Favors Secondary Bacterial Adhesion and Biofilm Re-Development

    PubMed Central

    Ohsumi, Tatsuya; Takenaka, Shoji; Wakamatsu, Rika; Sakaue, Yuuki; Narisawa, Naoki; Senpuku, Hidenobu; Ohshima, Hayato; Terao, Yutaka; Okiji, Takashi

    2015-01-01

    Chemical disinfection of oral biofilms often leaves biofilm structures intact. This study aimed to examine whether the residual structure promotes secondary bacterial adhesion. Streptococcus mutans biofilms generated on resin-composite disks in a rotating disc reactor were disinfected completely with 70% isopropyl alcohol, and were again cultured in the same reactor after resupplying with the same bacterial solution. Specimens were subjected to fluorescence confocal laser scanning microscopy, viable cell counts and PCR-Invader assay in order to observe and quantify secondarily adhered cells. Fluorescence microscopic analysis, particularly after longitudinal cryosectioning, demonstrated stratified patterns of viable cells on the disinfected biofilm structure. Viable cell counts of test specimens were significantly higher than those of controls, and increased according to the amount of residual structure and culture period. Linear regression analysis exhibited a high correlation between viable and total cell counts. It was concluded that disinfected biofilm structures favored secondary bacterial adhesion. PMID:25635770

  11. Pilot Study for UVA-LED Disinfection of Escherichia coli in Water for Space and Earth Applications

    NASA Technical Reports Server (NTRS)

    Ragolta, Carolina

    2010-01-01

    To test the efficacy of UVA-LED disinfection, a solution of Escherichia coli was pumped through a modified drip flow reactor at a flow rate of 1 ml/min. The experiment was conducted in a controlled environment chamber to ensure that temperature did not cause disinfection. The reactor featured three wells with different treatments: UVA-LED irradiation, UVA-LEDs with Ti02, and UVA-LEDs with nanosilver. Samples from each well were taken throughout a 340 hour period, inactivated, assayed, and analyzed for E. coli disinfection. Results of the duplicate experiments indicated longer exposure times are needed for UVA-LED disinfection of E. coli in water. Further research would consider a longer sampling period and different test conditions, such as increased contact area and various flow rates.

  12. An environmental disinfection odyssey: evaluation of sequential interventions to improve disinfection of Clostridium difficile isolation rooms.

    PubMed

    Sitzlar, Brett; Deshpande, Abhishek; Fertelli, Dennis; Kundrapu, Sirisha; Sethi, Ajay K; Donskey, Curtis J

    2013-05-01

    OBJECTIVE. Effective disinfection of hospital rooms after discharge of patients with Clostridium difficile infection (CDI) is necessary to prevent transmission. We evaluated the impact of sequential cleaning and disinfection interventions by culturing high-touch surfaces in CDI rooms after cleaning. DESIGN. Prospective intervention. SETTING. A Veterans Affairs hospital. INTERVENTIONS. During a 21-month period, 3 sequential tiered interventions were implemented: (1) fluorescent markers to provide monitoring and feedback on thoroughness of cleaning facility-wide, (2) addition of an automated ultraviolet radiation device for adjunctive disinfection of CDI rooms, and (3) enhanced standard disinfection of CDI rooms, including a dedicated daily disinfection team and implementation of a process requiring supervisory assessment and clearance of terminally cleaned CDI rooms. To determine the impact of the interventions, cultures were obtained from CDI rooms after cleaning and disinfection. RESULTS. The fluorescent marker intervention improved the thoroughness of cleaning of high-touch surfaces (from 47% to 81% marker removal; P < .0001). Relative to the baseline period, the prevalence of positive cultures from CDI rooms was reduced by 14% (P=.024), 48% (P <.001), and 89% (P=.006) with interventions 1, 2, and 3, respectively. During the baseline period, 67% of CDI rooms had positive cultures after disinfection, whereas during interventions periods 1, 2, and 3 the percentages of CDI rooms with positive cultures after disinfection were reduced to 57%, 35%, and 7%, respectively. CONCLUSIONS. An intervention that included formation of a dedicated daily disinfection team and implementation of a standardized process for clearing CDI rooms achieved consistent CDI room disinfection. Culturing of CDI rooms provides a valuable tool to drive improvements in environmental disinfection. PMID:23571361

  13. The effect of cavity disinfectants on microleakage in dentin bonding systems.

    PubMed

    Tulunoglu, O; Ayhan, H; Olmez, A; Bodur, H

    1998-01-01

    The purpose of this study was to determine the effect on microleakage of two disinfectants, one a chlorhexidine based and the other alcohol based, used as cavity washes prior to the application of one step dentin bonding systems Syntac and Prime & Bond in Class V composite restorations. Children between 10-12 years old, with noncarious second primary molars about to exfoliate, were selected for this study. Cavity preparations were treated with either Syntac or Prime & Bond, combinations of one of the two disinfectants washes with Syntac or Prime & Bond or with one of the disinfectants only and filled with Tetric composite resin. All teeth were extracted one month later, stained and sectioned to evaluate dye penetration. As a result, focal dry disinfectant when used as a cavity wash prior to the use of Prime & Bond did not effect the ability of dentin bonding agents to prevent microleakage. Chlorhexidine solution had an adverse effect on Syntac and Prime & Bond and produced significantly higher microleakage when used with these bonding systems. The use of cavity disinfectants with composite resin restorations appears to be material specific regarding the interactions with various dentin bonding systems and the ability to seal dentin. PMID:9796499

  14. The role of phytoplankton as pre-cursors for disinfection by-product formation upon chlorination.

    PubMed

    Tomlinson, Adam; Drikas, Mary; Brookes, Justin D

    2016-10-01

    Water quality remains one of the greatest concerns with regards to human health. Advances in science and technology have resulted in highly efficient water treatment plants, significantly reducing diseases related to waterborne pathogenic microorganisms. While disinfection is critical to mitigate pathogen risk to humans, the reactions between the disinfectant and dissolved organic compounds can lead to the formation of chemical contaminants called disinfection by-products (DBPs). DBPs have been related to numerous health issues including birth defects and cancer. The formation of disinfection by-products occurs due to the reaction of oxidants and natural organic matter. DBP precursors are derived from anthropogenic sources including pharmaceuticals and chemical waste, the breakdown of vegetation from external catchment sources (allochthonous) and internally derived sources including phytoplankton (autochthonous). Current literature focuses on the contribution of allochthonous sources towards the formation of DBPs, however, the recalcitrant nature of hydrophilic phytoplankton derived organic matter indicates that autochthonous derived organic carbon can significantly contribute to total DBP concentrations. The contribution of phytoplankton to the formation of DBPs is also influenced by cellular exudation rates, chemical composition, environmental conditions and the physical and chemical conditions of the solution upon disinfection. Formation of DBPs is further influenced by the presence of cyanobacteria phyla due to their notoriety for forming dense blooms. Management of DBP formation can potentially be improved by reducing cyanobacteria as well as DBP precursors derived from other phytoplankton. PMID:27348195

  15. Optimization of fixed titanium dioxide film on PET bottles and visual indicator for water disinfection

    NASA Astrophysics Data System (ADS)

    Heredia-Munoz, Manuel Antonio

    Water is perhaps the most important resource that sustains human life. According to the World Health Organization (WHO), almost two billion people do not have access to the required water that is needed to satisfy their daily needs and one billion do not have access to clean sources of water for consumption, most of them living in isolated and poor areas around the globe. Poor quality water increases the risk of cholera, typhoid fever and dysentery, and other water-borne illness making this problem a real crisis that humankind is facing. Several water disinfection technologies have been proposed as solutions for this problem. Solar water disinfection using TiO2 coated PET bottles was the alternative that is studied in this work. This technology does not only inactivate bacteria but also disintegrates organic chemicals that can be present in water. The objectives of this work address the optimization of the TiO 2 coated PET bottles technologies. The improvement on the bottle coating process, using two coats of 10% W/V of TiO2 in a solution of vinegar and sodium bicarbonate to form the TiO2 film, the use of a different indigo carmine (1.25 X 10-1mg/pill) concentration in the pill indicator of contamination, the increase of the disinfection rate through shaking the bottles, degradation under intermittent UV radiation and the effect of bottle size on photocatalytic water disinfection were among the most important findings. A new mathematical model that describes better photocatalytic water disinfection in TiO2 coated bottles and simulates water disinfection under different working conditions was another important achievement. These results can now be used to design a strategy for disseminating this technology in areas where it is required and, in that way, generate the greatest positive impact on the people needing safe drinking water.

  16. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level Goals and Maximum...

  17. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level Goals and Maximum...

  18. 40 CFR 141.54 - Maximum residual disinfectant level goals for disinfectants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Maximum residual disinfectant level goals for disinfectants. 141.54 Section 141.54 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Level Goals and Maximum...

  19. Impact of chlorinated disinfection on copper corrosion in hot water systems

    NASA Astrophysics Data System (ADS)

    Montes, J. Castillo; Hamdani, F.; Creus, J.; Touzain, S.; Correc, O.

    2014-09-01

    In France, hot water quality control inside buildings is occasionally ensured by disinfection treatments using temperature increases or addition of sodium hypochlorite (between 0.5 ppm and 1 ppm residual free chlorine). This disinfectant is a strong oxidiser and it could interact with metallic pipes usually used in hot water systems. This work deals with the study of the impact of these treatments on the durability of copper pipes. The objective of this work was to investigate the influence of sodium hypochlorite concentration and temperature on the copper corrosion mechanism. Copper samples were tested under dynamic and static conditions of ageing with sodium hypochlorite solutions ranging from 0 to 100 ppm with temperature at 50 °C and 70 °C. The efficiency of a corrosion inhibitor was investigated in dynamic conditions. Visual observations and analytical analyses of the internal surface of samples was studied at different ageing duration. Corrosion products were characterised by X-ray diffraction and Raman spectroscopy. Temperature and disinfectant were found to considerably affect the copper corrosion mechanism. Surprisingly, the corrosiveness of the solution was higher at lower temperatures. The temperature influences the nature of corrosion products. The protection efficiency is then strongly depend on the nature of the corrosion products formed at the surface of copper samples exposed to the aggressive solutions containing different concentration of disinfectant.

  20. Efficacy of multipurpose solutions for rigid gas permeable lenses.

    PubMed

    Boost, Maureen; Cho, Pauline; Lai, Sindy

    2006-09-01

    The use of multipurpose solutions for cleaning and disinfecting rigid gas permeable lenses has replaced single purpose solutions, but there are no reports of the efficacy of these multipurpose solutions, or of the effects of storage conditions on their disinfecting capacities. This study investigated activity against four bacterial and two fungal species, and the effects of storage in a refrigerator, at room temperature, at elevated temperature in both dry and humid conditions and with exposure to sunlight. The disinfecting solutions were challenged with the micro-organisms initially upon opening and then at 2-weekly intervals up to 12 weeks after being stored under the different conditions. Solutions were opened daily to simulate use. One solution failed to meet Food and Drug Administration (FDA) criteria to reduce numbers of bacteria by three log dilutions and of fungi by one log dilution. Storage reduced activity of all solutions over the 12-week period, but not below the requirements of the FDA. Storage in the refrigerator tended to reduce disinfecting capacity more quickly. Multipurpose solutions for rigid gas permeable (RGP) lenses lose activity over the 3 months recommended time of use but remain satisfactory for use over this time in the conditions tested. Practitioners need to remind patients to replace their solutions regularly and should advise against storage in the refrigerator. Multipurpose solutions for RGP lenses have simplified cleaning and disinfecting processes and the current formulations have improved disinfecting capacity compared to former disinfecting solutions, which is particularly important for wearers of orthokeratology lenses. PMID:16918771

  1. Resistance of Legionella to disinfection in hot water distribution systems.

    PubMed

    Saby, S; Vidal, A; Suty, H

    2005-01-01

    The efficiency of various disinfection treatments against Legionella was tested on a hot water distribution system (HWDS) pilot unit. The results demonstrated clearly that most Legionella in the networks were fixed in the biofilm at the surface of the pipe (more than 98% for each loop). Chemical treatments (continuous chlorination, hyperchlorination, hydrogen peroxide and peracetic acid mixing) commonly used for the eradication of Legionella in hot water distribution networks appeared to be inadequate for eradicating the bacteria in the biofilm. Unfortunately, the biofilm contained most of the pathogens in an HWDS whereas legislation is only restricted to the Legionella concentration in the water phase. Thermal treatment appeared to be efficient to disinfect most of the biofilm but seemed to promote the biofilm re-growth as well. It was then concluded that the best solution to prevent Legionella contamination in hot water distribution systems would be to have perfect control of the temperature in the networks (temperature > 55 degrees C at all points). Nevertheless, in many cases it is difficult to have such control, so during the time necessary to modify networks, the best solution to control Legionella proliferation appears to be to apply a treatment shock (thermal or chlorination as a function of pipe characteristics). These treatments must be followed by a continuous chlorination that is totally controlled and equipped with alarm systems. This study demonstrates that biofilm sampling devices must be installed in hot water distribution systems to anticipate Legionella contamination and correctly determine the efficiency of the treatments. PMID:16312947

  2. PARTICLE ASSOCIATION EFFECTS ON MICROBIAL INDICATOR CONCENTRATIONS AND CSO DISINFECTION

    EPA Science Inventory

    Combined sewer overflow (CSO) and wastewater disinfection effectiveness are evaluated by measuring microbial indicator concentrations before and after disinfection. The standard techniques for quantifying indicators are membrane filtration and multiple-tube fermentation/most pro...

  3. 42 CFR 71.42 - Disinfection of imports.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... imports. When the cargo manifest of a carrier lists articles which may require disinfection under the provisions of this part, the Director shall disinfect them on board or request the appropriate...

  4. 42 CFR 71.42 - Disinfection of imports.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... imports. When the cargo manifest of a carrier lists articles which may require disinfection under the provisions of this part, the Director shall disinfect them on board or request the appropriate...

  5. 42 CFR 71.42 - Disinfection of imports.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... imports. When the cargo manifest of a carrier lists articles which may require disinfection under the provisions of this part, the Director shall disinfect them on board or request the appropriate...

  6. 42 CFR 71.42 - Disinfection of imports.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... imports. When the cargo manifest of a carrier lists articles which may require disinfection under the provisions of this part, the Director shall disinfect them on board or request the appropriate...

  7. 42 CFR 71.42 - Disinfection of imports.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... imports. When the cargo manifest of a carrier lists articles which may require disinfection under the provisions of this part, the Director shall disinfect them on board or request the appropriate...

  8. Formation and Occurrence of Disinfection By-Products

    EPA Science Inventory

    Disinfection by-products (DBPs) are formed when disinfectants such as chlorine, ozone, chlorine dioxide, or chloramines react with naturally occurring organic matter, anthropogenic contaminants, bromide, and iodide during the production of drinking water. There is concern about D...

  9. MULTISPECTRAL IDENTIFICATION OF CHLORINE DIOXIDE DISINFECTION BYPRODUCTS IN DRINKING WATER

    EPA Science Inventory

    This paper discusses the identification of organic disinfection byproducts (DBPs) at a pilot plant in Evansville, IN, which uses chlorine dioxide as a primary disinfectant. Unconventional multispectral identification techniques (gas chromatography combined with high- and low reso...

  10. Comparison of Disinfectants for Control of Listeria Biofilms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: The generation of protective biofilms by microorganisms that aggregate on food processing equipment surfaces is a major contributing factor to contamination and disinfection failure in meat and poultry processing facilities. Traditional disinfectants and cleaners do not effectively h...

  11. DISINFECTION PROCESSES AND STABILITY REFINEMENTS TO BIOSOLIDS TREATMENT TECHNOLOGIES

    EPA Science Inventory

    This paper reviews the current US sewage sludge disinfection regulations and their associated practices; discusses the limitations of the practices; discusses the criteria employed in evaluating a new (innovative or alternative) disinfection process and both notes some processes ...

  12. The History And Future Directions Of Biosolids Disinfection

    EPA Science Inventory

    This paper reviews the history of disinfection practices, emphasizing their application to human fecal material and the residuals from wastewater treatment. It discusses development of the current US sewage sludge disinfection regulations and their associated practices; discusse...

  13. The History And Future Directions Of Biosolids Disinfection (Presentation)

    EPA Science Inventory

    This paper reviews the history of disinfection practices, emphasizing their application to human fecal material and the residuals from wastewater treatment. It discusses development of the current US sewage sludge disinfection regulations and their associated practices; discusse...

  14. Evidence of effective penetration of Listeria monocytogenes biofilms by disinfectant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The generation of protective biofilms by microorganisms that aggregate on food processing equipment surfaces is a major contributing factor to contamination and disinfection failure in meat and poultry processing facilities. Traditional disinfectants and cleaners do not effectively penetrate the bi...

  15. DISINFECTION OF BACTERIA ATTACHED TO GRANULAR ACTIVATED CARBON

    EPA Science Inventory

    Heterotrophic plate count bacteria, coliform organisms, and pathogenic microorganisms attached to granular activated carbon (GAC) particles were examined for their susceptibility to chlorine disinfection. When these bacteria were grown on carbon particles and then disinfected wit...

  16. [Evaluation of surface disinfectants utilized in dentistry].

    PubMed

    Silva, Célia Regina Gonçalves e; Jorge, Antonio Olavo Cardoso

    2002-01-01

    Surface disinfection is a procedure carried out on the external parts of the dental equipment as well as on other items of the dental office. The aim of this study was to analyze the efficacy of 4 surface disinfectants utilized in dentistry: 77 degrees GL alcohol, phenolic compound (Duplofen), iodophor (PVP-I) and 77 degrees GL alcohol with 5% of chlorhexidine. Four surfaces of the equipment were analyzed in the study (the carter, the washbasin for hand-washing, the headrest of the chair and the external surface of the reflector), and the spray-wipe-spray procedure was carried out. From each surface, samples were collected by means of surface plates containing Mitis Salivarius bacitracin sucrose agar, Sabouraud Dextrose agar with chloramphenicol, MacConkey agar and blood agar, for counting mutans streptococci, Candida yeasts, gram-negative bacteria and total microorganisms, respectively (ufc/plate). The results were statistically analyzed by means of the Student's t test in order to compare the mean ufc/plate values. The most effective disinfectant was 77 degrees GL alcohol with 5% of chlorhexidine, mainly against gram-positive bacteria. Iodophor and phenolic compound were also effective in microbial reduction. 77 degrees GL alcohol was the least effective product - however, although it is not considered as a surface disinfectant, it produced, in this study, statistically significant microbial reduction after the disinfecting procedure. PMID:12131982

  17. Reduction of Acid-Fast and Non-Acid-Fast Bacteria by Point of Use Coagulation-Flocculation-Disinfection

    PubMed Central

    Casanova, Lisa M.; Sobsey, Mark D.

    2015-01-01

    Point of use (POU) household water treatment is increasingly being adopted as a solution for access to safe water. Non-tuberculous Mycobacteria (NTM) are found in water, but there is little research on whether NTM survive POU treatment. Mycobacteria may be removed by multi-barrier treatment systems that combine processes such as coagulation, settling and disinfection. This work evaluated removal of a non-tuberculous Mycobacterium (Mycobaterium terrae) and a Gram-negative non-acid-fast environmental bacterium (Aeromonas hydrophila) by combined coagulation-flocculation disinfection POU treatment. Aeromonas hydrophila showed 7.7 log10 reduction in demand free buffer, 6.8 log10 in natural surface water, and 4 log10 reduction in fecally contaminated surface water. Turbidity after treatment was <1 NTU. There was almost no reduction in levels of viable M. terrae by coagulant-flocculant-disinfectant in natural water after 30 minutes. The lack of Mycobacteria reduction was similar for both combined coagulant-flocculant-disinfectant and hypochlorite alone. A POU coagulant-flocculant-disinfectant treatment effectively reduced A. hydrophila from natural surface waters but not Mycobacteria. These results reinforce previous findings that POU coagulation-flocculation-disinfection is effective against gram-negative enteric bacteria. POU treatment and safe storage interventions may need to take into account risks from viable NTM in treated stored water and consider alternative treatment processes to achieve NTM reductions. PMID:26580632

  18. Reduction of Acid-Fast and Non-Acid-Fast Bacteria by Point of Use Coagulation-Flocculation-Disinfection.

    PubMed

    Casanova, Lisa M; Sobsey, Mark D

    2015-11-01

    Point of use (POU) household water treatment is increasingly being adopted as a solution for access to safe water. Non-tuberculous Mycobacteria (NTM) are found in water, but there is little research on whether NTM survive POU treatment. Mycobacteria may be removed by multi-barrier treatment systems that combine processes such as coagulation, settling and disinfection. This work evaluated removal of a non-tuberculous Mycobacterium (Mycobaterium terrae) and a Gram-negative non-acid-fast environmental bacterium (Aeromonas hydrophila) by combined coagulation-flocculation disinfection POU treatment. Aeromonas hydrophila showed 7.7 log10 reduction in demand free buffer, 6.8 log10 in natural surface water, and 4 log10 reduction in fecally contaminated surface water. Turbidity after treatment was <1 NTU. There was almost no reduction in levels of viable M. terrae by coagulant-flocculant-disinfectant in natural water after 30 minutes. The lack of Mycobacteria reduction was similar for both combined coagulant-flocculant-disinfectant and hypochlorite alone. A POU coagulant-flocculant-disinfectant treatment effectively reduced A. hydrophila from natural surface waters but not Mycobacteria. These results reinforce previous findings that POU coagulation-flocculation-disinfection is effective against gram-negative enteric bacteria. POU treatment and safe storage interventions may need to take into account risks from viable NTM in treated stored water and consider alternative treatment processes to achieve NTM reductions. PMID:26580632

  19. Potential application of high pressure carbon dioxide in treated wastewater and water disinfection: Recent overview and further trends.

    PubMed

    Vo, Huy Thanh; Imai, Tsuyoshi; Ho, Truc Thanh; Dang, Thanh-Loc Thi; Hoang, Son Anh

    2015-10-01

    Recently emerging disadvantages in conventional disinfection have heightened the need for finding a new solution. Developments in the use of high pressure carbon dioxide for food preservation and sterilization have led to a renewed interest in its applicability in wastewater treatment and water disinfection. Pressurized CO2 is one of the most investigated methods of antibacterial treatment and has been used extensively for decades to inhibit pathogens in dried food and liquid products. This study reviews the literature concerning the utility of CO2 as a disinfecting agent, and the pathogen inactivation mechanism of CO2 treatment is evaluated based on all available research. In this paper, it will be argued that the successful application and high effectiveness of CO2 treatment in liquid foods open a potential opportunity for its use in wastewater treatment and water disinfection. The findings from models with different operating conditions (pressure, temperature, microorganism, water content, media …) suggest that most microorganisms are successfully inhibited under CO2 treatment. It will also be shown that the bacterial deaths under CO2 treatment can be explained by many different mechanisms. Moreover, the findings in this study can help to address the recently emerging problems in water disinfection, such as disinfection by-products (resulting from chlorination or ozone treatment). PMID:26456604

  20. The Source, Spatial Distribution and Risk Assessment of Heavy Metals in Soil from the Pearl River Delta Based on the National Multi-Purpose Regional Geochemical Survey

    PubMed Central

    Zhang, Lingyan; Guo, Shuhai; Wu, Bo

    2015-01-01

    The data on the heavy metal content at different soil depths derived from a multi-purpose regional geochemical survey in the Pearl River Delta (PRD) were analyzed using ArcGIS 10.0. By comparing their spatial distributions and areas, the sources of heavy metals (Cd, Hg, As and Pb) were quantitatively identified and explored. Netted measuring points at 25 ×25 km were set over the entire PRD according to the geochemical maps. Based on the calculation data obtained from different soil depths, the concentrations of As and Cd in a large area of the PRD exceeded the National Second-class Standard. The spatial disparity of the geometric centers in the surface soil and deep soil showed that As in the surface soil mainly came from parent materials, while Cd had high consistency in different soil profiles because of deposition in the soil forming process. The migration of Cd also resulted in a considerable ecological risk to the Beijiang and Xijiang River watershed. The potential ecological risk index followed the order Cd ≥ Hg > Pb > As. According to the sources, the distribution trends and the characteristics of heavy metals in the soil from the perspective of the whole area, the Cd pollution should be repaired, especially in the upper reaches of the Xijiang and Beijiang watershed to prevent risk explosion while the pollution of Hg and Pb should be controlled in areas with intense human activity, and supervision during production should be strengthened to maintain the ecological balance of As. PMID:26230506

  1. Multi-purpose droop controllers incorporating a passivity-based stabilizer for unified control of electronically interfaced distributed generators including primary source dynamics.

    PubMed

    Azimi, Seyed Mohammad; Afsharnia, Saeed

    2016-07-01

    This paper presents multi-purpose droop controllers for electronically-interfaced distributed generators (EI-DGs). These controllers allow the micro-grids to operate in grid-connected mode, islanded mode and mode transition transients with a unique control configuration. The active and reactive-power sharing among EI-DGs are satisfied by the proposed droop controllers in islanded mode. On the other hand, in the grid-connected mode, the droop controllers adjust the output active and reactive-powers of EI-DGs at the pre-programmed constant levels. The provision of sufficient damping capability and maintenance of the transient stability in all operational modes of EI-DGs are warranted by the suggested stabilizer. This stabilizer, which is designed using the passivity-based control (PBC) approach, is incorporated in the droop controllers to dampen power-angle, frequency and voltage deviations during large transients using solely local information. The primary source dynamics of EI-DGs are also considered. It is analytically proven that the presence of the primary source dynamics leads to attenuation of the damping capability of EI-DGs in transients. To compensate the adverse effect of the primary source dynamics during transients a novel compensator is inserted in the frequency-droop loop. Finally, time-domain simulations are performed on a multi-resources MG to verify the analytical results compared to those obtained, based on a recently-developed strategy. PMID:27085670

  2. Investigation of stress in a circular tunnel due to overburden and thermal loading of horizontally placed 21 PWR multi purpose canisters

    SciTech Connect

    Kandalaft-Ladkany, N.; Wyman, R.V.

    1994-05-01

    The drift of a High Level Nuclear Waste (HLNW) Repository were subjected to 2-D thermal loading resulting from the horizontal emplacement of 125 Ton Multi-Purpose Canisters (MPC). Ten 2-D temperature profiles, resulting from 57 Kw/acre and 114 Kw/acre thermal loading conditions, were used in a finite element analysis of the drift; in which a quadrant of the drift and surrounding rock {plus_minus}100m above and below the drift were modeled. Our analysis shows that the 114 Kw/acre thermal loading results in compressive stresses around the drift, 60 years after emplacement, that exceed the unconfined compressive strength of the TSW tuff analyzed. Stresses resulting from a 57 Kw/acre thermal loading are within the acceptable limit in tunnel rock. A parametric analysis of the invert backfill material showed that Young`s modulus for the invert backfill should closely match that of the surrounding unconfined rock in the tunnel in order to prevent an unacceptable stress rise in both rock and backfill.

  3. Profiling glucosinolates and phenolics in vegetative and reproductive tissues of the multi-purpose trees Moringa oleifera L. (horseradish tree) and Moringa stenopetala L.

    PubMed

    Bennett, Richard N; Mellon, Fred A; Foidl, Nikolaus; Pratt, John H; Dupont, M Susan; Perkins, Lionel; Kroon, Paul A

    2003-06-01

    Moringa species are important multi-purpose tropical crops, as human foods and for medicine and oil production. There has been no previous comprehensive analysis of the secondary metabolites in Moringa species. Tissues of M. oleifera from a wide variety of sources and M. stenopetala from a single source were analyzed for glucosinolates and phenolics (flavonoids, anthocyanins, proanthocyanidins, and cinnamates). M. oleifera and M. stenopetala seeds only contained 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate at high concentrations. Roots of M. oleifera and M. stenopetala had high concentrations of both 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate and benzyl glucosinolate. Leaves from both species contained 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate and three monoacetyl isomers of this glucosinolate. Only 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate was detected in M. oleifera bark tissue. M. oleifera leaves contained quercetin-3-O-glucoside and quercetin-3-O-(6' '-malonyl-glucoside), and lower amounts of kaempferol-3-O-glucoside and kaempferol-3-O-(6' '-malonyl-glucoside). M. oleifera leaves also contained 3-caffeoylquinic acid and 5-caffeoylquinic acid. Leaves of M. stenopetala contained quercetin 3-O-rhamnoglucoside (rutin) and 5-caffeoylquinic acid. Neither proanthocyanidins nor anthocyanins were detected in any of the tissues of either species. PMID:12769522

  4. Inhibition of Wnt signalling and breast tumour growth by the multi-purpose drug suramin through suppression of heterotrimeric G proteins and Wnt endocytosis.

    PubMed

    Koval, Alexey; Ahmed, Kamal; Katanaev, Vladimir L

    2016-02-15

    Overactivation of the Wnt signalling pathway underlies oncogenic transformation and proliferation in many cancers, including the triple-negative breast cancer (TNBC), the deadliest form of tumour in the breast, taking about a quarter of a million lives annually worldwide. No clinically approved targeted therapies attacking Wnt signalling currently exist. Repositioning of approved drugs is a promising approach in drug discovery. In the present study we show that a multi-purpose drug suramin inhibits Wnt signalling and proliferation of TNBC cells in vitro and in mouse models, inhibiting a component in the upper levels of the pathway. Through a set of investigations we identify heterotrimeric G proteins and regulation of Wnt endocytosis as the likely target of suramin in this pathway. G protein-dependent endocytosis of plasma membrane-located components of the Wnt pathway was previously shown to be important for amplification of the signal in this cascade. Our data identify endocytic regulation within Wnt signalling as a promising target for anti-Wnt and anti-cancer drug discovery. Suramin, as the first example of such drug or its analogues might pave the way for the appearance of first-in-class targeted therapies against TNBC and other Wnt-dependent cancers. PMID:26604320

  5. New non-alcoholic formulation for hand disinfection.

    PubMed

    Biagi, Marco; Giachetti, Daniela; Miraldi, Elisabetta; Figura, Natale

    2014-04-01

    Hand washing is considered as the single most important strategy to prevent infections. World health organization (WHO) defines hand hygiene as a primary issue of personal care with particular reference to hospital personnel and health facility workers. In this work, we investigated a new combination for hand disinfection as an alternative to alcohol-based and chlorhexidine products. The new combination of 5-pyrrolidone-2-carboxylic acid (PCA) and copper sulphate pentahydrate (CS) was tested upon different bacterial species that normally colonize hands, including Staphylococcus aureus, methicillin resistant S. aureus (MR S. aureus), Staphylococcus epidermidis, multidrug resistant S. epidermidis (MDR S. epidermidis), Streptococcus pyogenes, Streptococcus agalactiae, Escherichia coli, Candida albicans and three clinical isolates: MR S. aureus, MDR S. epidermidis, and an E. coli strain. Minimal inhibitory concentrations (MICs), Minimal bactericidal concentrations (MBCs), fractional inhibitory concentration (FIC) indices, and fractional bactericidal concentration (FBC) indices were evaluated. Ethanol 70% V/V, isopropanol 60% V/V, and 4% w/V chlorhexidine solution were used as reference hand disinfectants. Copper sulphate pentahydrate was very effective against all tested microorganisms: The MIC and MBC for CS ranged from 781 mg/l against S. pyogenes to 12500 mg/l against E. coli strains and C. albicans. In addition, PCA exhibited a good antimicrobial activity, in particular, against S. pyogenes and S. agalactiae. The combination of CS and PCA showed a strong synergistic effect and all FIC indices were ≤0·500. The combination of CS and PCA were more effective than ethanol 70% V/V and isopropanol 60% V/V. In addition to antimicrobial activity, the new formulation possesses peculiar features such as residual activity and moisturizing effect. This work identifies a new strategy for hand disinfection. PMID:24090970

  6. Variability of Burkholderia pseudomallei strain sensitivities to chlorine disinfection.

    PubMed

    O'Connell, Heather A; Rose, Laura J; Shams, Alicia; Bradley, Meranda; Arduino, Matthew J; Rice, Eugene W

    2009-08-01

    Burkholderia pseudomallei is a select agent and the causative agent of melioidosis. Variations in previously reported chlorine and monochloramine concentration time (Ct) values for disinfection of this organism make decisions regarding the appropriate levels of chlorine in water treatment systems difficult. This study identified the variation in Ct values for 2-, 3-, and 4-log(10) reductions of eight environmental and clinical isolates of B. pseudomallei in phosphate-buffered water. The greatest calculated Ct values for a 4-log(10) inactivation were 7.8 mg.min/liter for free available chlorine (FAC) at pH 8 and 5 degrees C and 550 mg.min/liter for monochloramine at pH 8 and 5 degrees C. Ionic strength of test solutions, culture hold times in water, and cell washing were ruled out as sources of the differences in prior observations. Tolerance to FAC was correlated with the relative amount of extracellular material produced by each isolate. Solid-phase cytometry analysis using an esterase-cleaved fluorochrome assay detected a 2-log(10)-higher level of organisms based upon metabolic activity than did culture, which in some cases increased Ct values by fivefold. Despite strain-to-strain variations in Ct values of 17-fold for FAC and 2.5-fold for monochloramine, standard FAC disinfection practices utilized in the United States should disinfect planktonic populations of these B. pseudomallei strains by 4 orders of magnitude in less than 10 min at the tested temperatures and pH levels. PMID:19542324

  7. EFFICACY OF NOVEL WATER DISINFECTION TECHNIQUES IN HORTICULTURAL NUTRIENT RECYCLING.

    PubMed

    Heungens, K; Clierinck, M; Inghelbrecht, S; Vissers, M

    2015-01-01

    Hydroponic systems used for growing potted ornamentals in greenhouses are commonly ebb-and-flow irrigation systems. The drainage water is usually recycled to save water and nutrients. To avoid the spread of pathogens in these closed irrigation systems, disinfection of the recycled water is standard practice. Growers can use slow sand filtration or UV-radiation techniques, but these methods are often either not sulted for specific problems or they require an excessively large investment. The objective of this study was to test less expensive but effective alternative disinfection systems. The efficacy of five disinfection systems against fungi and oomycetes was determined: Aqua-Hort (based on Cu-ions), Reciclean (performic acid), D1-OX Forte (CIO2), ECA (electrochemically activated water = anodic oxidation: hypochlorite and free radicals) and Newtec (also anodic oxidation). These five systems and a no-sterilization control were integrated in small closed ebb-and-flow circuits with nutrient solution reservoirs of 400 L each. Activity against Fusarium was excellent with ECA, good with Newtec and DI-OX Forte, moderate with high doses of Reciclean (250 ppm H2O2 and poor with the Aqua-Hort. There was no Pythium in the ECA and Newtec systems, while still so in the Aqua-Hort system, even at high doses (up to 7 ppm Cu++). Although the Reciclean (up to 100 ppm H2O2) and Aqua-Hort systems did not perform well against the pathogens, they did very well against algae; especially Reciclean was also useful against duckweed in water and liverwort on soil substrates. Concentrations of total Cl were elevated in water, substrate and plants after treatments with ECA and Newtec; other accumulations were Cu (Aqua-Hort), Na and SO4 (DI-OX Forte). However, only on a limited number of plant species these accumulations produced phytotoxic effects. PMID:27141749

  8. An insight of disinfection by-product (DBP) formation by alternative disinfectants for swimming pool disinfection under tropical conditions.

    PubMed

    Yang, Linyan; Schmalz, Christina; Zhou, Jin; Zwiener, Christian; Chang, Victor W-C; Ge, Liya; Wan, Man Pun

    2016-09-15

    Sodium hypochlorite (NaClO) is the most commonly used disinfectant in pool treatment system. Outdoor pools usually suffer from the strong sunlight irradiation which degrades the free chlorine rapidly. In addition, more pools start to adopt the recirculation of swimming pool water, which intensifies the disinfection by-product (DBP) accumulation issue. Given these potential drawbacks of using NaClO in the tropical environment, two alternative organic-based disinfectants, trichloroisocyanuric acid (TCCA, C3Cl3N3O3) and bromochlorodimethylhydantoin (BCDMH, C5H6BrClN2O2), were investigated and compared to NaClO in terms of their self-degradation and the formation of DBPs, including trihalomethanes (THMs) and haloacetic acids (HAAs), under simulated tropical climate conditions. The result reveals that halogen stabilizer, TCCA, had the advantages of slower free chlorine degradation and lower DBP concentration compared to NaClO, which makes it a good alternative disinfectant. BCDMH was not recommended mainly due to the highly reactive disinfecting ingredient, hypobromous acid (HBrO), which fails to sustain the continuous disinfection requirement. Total disinfectant dosage was the main factor that affects residual chlorine/bromine and THM/HAA formation regardless of different disinfectant dosing methods, e.g. shock dosing (one-time spiking) in the beginning, and continuous dosing during the whole experimental period. Two-stage second-order-kinetic-based models demonstrate a good correlation between the measured and predicted data for chlorine decay (R(2) ≥ 0.95), THM (R(2) ≥ 0.99) and HAA (R(2) ≥ 0.83) formation. Higher temperature was found to enhance the DBP formation due to the temperature dependence of reaction rates. Thus, temperature control of pools, especially for those preferring higher temperatures (e.g. hydrotherapy and spa), should take both bather comfort and DBP formation potential into consideration. It is also observed that chlorine competition

  9. Evaluation of Vinegar as a Disinfectant for Extracted Human Teeth - An in-Vitro Study

    PubMed Central

    Ganipineni, Kiranmai; Babburi, Suresh; Venigalla, Aparna; Pinnisetti, Soujanya; Kotti, Ajay Benarji; Kalapala, Lavanya

    2016-01-01

    Introduction In dentistry, extracted human teeth are routinely used to learn technical and preclinical skills. Since human teeth harbour many pathogens these should be disinfected before use to minimize the risk of infections. Some commonly used disinfectants in laboratories are 10% formalin, 3% hydrogen peroxide (H2O2), 5.25% Sodium Hypochlorite (NaOCl), 70% alcohol and normal saline which have their own disadvantages like carcinogenicity, toxicity, cost effectiveness etc. Many studies have been conducted using these solutions but there is no evidence to suggest a suitable alternative for disinfecting extracted teeth. Vinegar is a sour liquid comprised mainly of acetic acid. It is cheap and commercially available shown to be effective in the prevention and control of microbial contamination. Aim The present study was conducted for evaluation of vinegar as a disinfectant for extracted teeth. Materials and Methods In this study a total of 40 (n=40) extracted non carious teeth were taken which were disinfected with various physical methods such as sterilization, autoclaving and chemical methods by using Vinegar, 70% Alcohol, 10% Formalin, 3% Hydrogen peroxide and 5.25% NaOCL. Later, teeth from each group were placed individually in separate test tubes containing 10ml of brain heart infusion broth at 37°C for 48 hrs to observe the evidence of growth of microorganisms. Results Results were analyzed using Kruskal-Wallis test. Vinegar, 10% Formalin and 3% Hydrogen peroxide were effective. The results were statistically significant with Kruskal-Wallis test value 28.053 and p-value was <0.001. Conclusion Vinegar can be used as an effective disinfectant for extracted human teeth.

  10. DETECTION OF INFECTIOUS ADENOVIRUS IN TERTIARY TREATED AND UV DISINFECTED WASTEWATER DURING A UV DISINFECTION PILOT STUDY

    EPA Science Inventory

    An infectious enteric adenovirus was isolated from urban wastewater receiving tertiary treatment and ultraviolet (UV) disinfection. A pilot study was undertaken to investigate the efficacy of UV disinfection (low pressure, high intensity radiation) of total and fecal coliform bac...

  11. Integrated Disinfection By-Products Mixtures Research: Disinfection of Drinking Waters by Chlorination and Ozonation/Postchlorination Treatment Scenarios

    EPA Science Inventory

    This article describes disinfection of the same source water by two commonly used disinfection treatment scenarios for purposes of subsequent concentration, chemical analysis, and toxicological evaluation. Accompanying articles in this issue of the Journal of Toxicology and Envir...

  12. A Toxicological Perspective on Disinfection ByProducts

    EPA Science Inventory

    Disinfection of water is essential for reduction of microbes harmful to human health and chemical disinfection is considered one of the major public health triumphs of the 20th Century. An unintended consequence of disinfection with oxidizing chemicals is formation of disinfectio...

  13. Studies on Disinfection By-Products and Drinking Water

    USGS Publications Warehouse

    Rostad, Colleen E.

    2007-01-01

    Drinking water is disinfected with chemicals to remove pathogens, such as Giardia and Cryptosproridium, and prevent waterborne diseases such as cholera and typhoid. During disinfection, by-products are formed at trace concentrations. Because some of these by-products are suspected carcinogens, drinking water utilities must maintain the effectiveness of the disinfection process while minimizing the formation of by-products.

  14. Proteomic Adaptations to Starvation Prepare Escherichia coli for Disinfection Tolerance

    PubMed Central

    Du, Zhe; Nandakumar, Renu; Nickerson, Kenneth; Li, Xu

    2015-01-01

    Despite the low nutrient level and constant presence of secondary disinfectants, bacterial re-growth still occurs in drinking water distribution systems. The molecular mechanisms that starved bacteria use to survive low-level chlorine-based disinfectants are not well understood. The objective of this study is to investigate these molecular mechanisms at the protein level that prepare starved cells for disinfection tolerance. Two commonly used secondary disinfectants chlorine and monochloramine, both at 1 mg/L, were used in this study. The proteomes of normal and starved Escherichia coli (K12 MG1655) cells were studied using quantitative proteomics. Over 60-min disinfection, starved cells showed significantly higher disinfection tolerance than normal cells based on the inactivation curves for both chlorine and monochloramine. Proteomic analyses suggest that starvation may prepare cells for the oxidative stress that chlorine-based disinfection will cause by affecting glutathione metabolism. In addition, proteins involved in stress regulation and stress responses were among the ones up-regulated under both starvation and chlorine/monochloramine disinfection. By comparing the fold changes under different conditions, it is suggested that starvation prepares E. coli for disinfection tolerance by increasing the expression of enzymes that can help cells survive chlorine/monochloramine disinfection. Protein co-expression analyses show that proteins in glycolysis and pentose phosphate pathway that were up-regulated under starvation are also involved in disinfection tolerance. Finally, the production and detoxification of methylglyoxal may be involved in the chlorine-based disinfection and cell defense mechanisms. PMID:25463932

  15. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  16. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  17. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  18. Environmental health perspectives. Volume 46. Drinking water disinfectants - December 1982

    SciTech Connect

    Lucier, G.W.; Hook, G.E.R.

    1982-01-01

    Among subjects considered are chlorine dioxide, N-chloramines, mutagenic activity by disinfectant reaction products, trihalomethane and behavioral toxicity, and carcinogenic risk estimation. There are 27 papers on these and related topics. The volume stems from a symposium on drinking water disinfectants and disinfectant by-products.

  19. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  20. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  1. 9 CFR 166.14 - Cleaning and disinfecting.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Cleaning and disinfecting. 166.14 Section 166.14 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE SWINE HEALTH PROTECTION SWINE HEALTH PROTECTION General Provisions § 166.14 Cleaning and disinfecting. (a) Disinfectants to be...

  2. 9 CFR 166.14 - Cleaning and disinfecting.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Cleaning and disinfecting. 166.14 Section 166.14 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE SWINE HEALTH PROTECTION SWINE HEALTH PROTECTION General Provisions § 166.14 Cleaning and disinfecting. (a) Disinfectants to be...

  3. OPTIMAL SCHEDULING OF BOOSTER DISINFECTION IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Booster disinfection is the addition of disinfectant at locations distributed throughout a water distribution system. Such a strategy can reduce the mass of disinfectant required to maintain a detectable residual at points of consumption in the distribution system, which may lea...

  4. THE TOXICOLOGY OF COMPLEX MIXTURES OF DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Chemical disinfection of water is a major public health advance that has decreased dramatically water-borne disease. Chemical disinfectants react with naturally occurring organic and inorganic matter in water to produce a wide variety of disinfection byproducts (DBPs). DBP num...

  5. TOXICOLOGIC AND CHEMICAL EVALUATION OF ALTERNATIVE DISINFECTION TREATMENT SCENARIOS

    EPA Science Inventory

    More than 500 disinfecting byproducts have been identified. They result from the reaction of the disinfectants with the natural organic matter present in source waters. The concentrations and bromo/chloro speciation of these disinfection byproducts (DBPs) are influenced by source...

  6. Antiseptics and Disinfectants: Activity, Action, and Resistance

    PubMed Central

    McDonnell, Gerald; Russell, A. Denver

    1999-01-01

    Antiseptics and disinfectants are extensively used in hospitals and other health care settings for a variety of topical and hard-surface applications. A wide variety of active chemical agents (biocides) are found in these products, many of which have been used for hundreds of years, including alcohols, phenols, iodine, and chlorine. Most of these active agents demonstrate broad-spectrum antimicrobial activity; however, little is known about the mode of action of these agents in comparison to antibiotics. This review considers what is known about the mode of action and spectrum of activity of antiseptics and disinfectants. The widespread use of these products has prompted some speculation on the development of microbial resistance, in particular whether antibiotic resistance is induced by antiseptics or disinfectants. Known mechanisms of microbial resistance (both intrinsic and acquired) to biocides are reviewed, with emphasis on the clinical implications of these reports. PMID:9880479

  7. Bactericidal properties of a new water disinfectant.

    PubMed Central

    Williams, D E; Worley, S D; Wheatley, W B; Swango, L J

    1985-01-01

    The N-chloramine compound 3-chloro-4,4-dimethyl-2-oxazolidinone (agent I) has been compared with calcium hypochlorite as to its efficacy as a bactericide for the treatment of water. The study included concentration, contact time, pH, temperature, and water quality as controlled variables. The species of bacteria tested were Staphylococcus aureus, Pseudomonas aeruginosa, and Shigella boydii. In general, for highly pure, demand-free water, calcium hypochlorite was the more rapid disinfectant at a given total chlorine concentration, although for water containing a controlled amount of organic load, agent I was the better disinfectant. The differences in efficacy of each of the two disinfectants can be attributed primarily to their different stabilities in water at various controlled conditions. PMID:3922300

  8. Sterilization and disinfection in the physician's office.

    PubMed Central

    Drummond, D C; Skidmore, A G

    1991-01-01

    OBJECTIVE: To review the principles and practice of sterilization and disinfection of medical instruments in the office setting. DATA SOURCES: Searches of MEDLINE for articles published from 1980 to 1990 on disinfection, sterilization, cross infection, surgical instruments and iatrogenic disease, bibliographies, standard texts and reference material located in a central processing department. STUDY SELECTION: We reviewed surveys of decontamination practices in physicians' offices, reviews of current recommendations for office decontamination procedures, case reports of cross infection in offices and much of the standard reference material on decontamination theory and practice. DATA SYNTHESIS: There have been few surveys of physicians' decontamination practices and few case reports of cross infection. Office practitioners have little access to practical information on sterilization and disinfection. CONCLUSION: The increasing threat of cross infection from medical instruments calls for greater knowledge about decontamination. We have adapted material from various sources and offer a primer on the subject. PMID:1913427

  9. Reproductive effects of alternative disinfectants.

    PubMed Central

    Carlton, B D; Barlett, P; Basaran, A; Colling, K; Osis, I; Smith, M K

    1986-01-01

    Organohalides formed through the reaction of chlorine and organic compounds in natural and waste waters pose potential health hazards. For this reason, alternative water disinfectants that do not form organohalides are being investigated with great interest. Limited data are available on the health effects, in particular reproductive toxicity effects, of these compounds. In our laboratory, we have examined the reproductive effects of chloramine and chlorine administered by gavage in Long-Evans rats. Animals were treated for a total of 66 to 76 days. Males were treated for 56 days and females for 14 days prior to breeding and throughout the 10-day breeding period. Females were treated throughout gestation and lactation. Following breeding, the males were necropsied and evaluated for sperm parameters and reproductive tract histopathology. Adult females and some pups were necropsied at weaning on postnatal day 21. Other pups were treated postweaning until 28 or 40 days of age. These pups were evaluated for the day of vaginal patency and thyroid hormone levels. No differences were observed between control rats and those rats exposed to up to 5 mg/kg/day chlorine or 10 mg/kg/day chloramine when fertility, viability, litter size, day of eye opening, or day of vaginal patency were evaluated. No alterations in sperm count, sperm direct progressive movement (micron/sec), percent motility, or sperm morphology were observed among adult male rats. In addition, male and female reproductive organ weights were comparable to their respective control groups, and no significant histopathologic changes were observed among chlorine- or chloramine-treated male and female rats. PMID:3816727

  10. New developments in disinfection and sterilization.

    PubMed

    Wallace, Craig A

    2016-05-01

    A review of regulatory clearances for selected new sterilization and disinfection products for the period January 2012-June 2015 indicates continued leverage of established technologies for steam and low-temperature sterilization, and high-level disinfection. New products in these areas were typically modified and improved versions of existing products, with the exception of a new combination hydrogen peroxide/ozone sterilizer. Development of new low-temperature sterilization technologies to address continued evolution of complex medical devices is expected to continue. PMID:27131131

  11. [Survey of methods of cleaning, decontamination, disinfection and sterilization in dental health services in tropical areas].

    PubMed

    Clapeau, G; Decroix, B; Bakayoko-Ly, R; Varenne, B; Dosso-Hien, D; Decroix, M O

    1997-01-01

    The International Aid for Ontology (IAO) carried out this survey of hygiene in the dental health services of 5 French-speaking African countries in 1994, in association with the Faculty of Pharmaceutical and Biological Sciences of Paris. This study received support from the World Health Organization (WHO), the French Ministry for Cooperation and the European Community and the Ivory Coast Oral and Dental Hygiene and Health Committee (CIHSBD). Twenty-nine dental services from Benin (3), Burkina Faso (6), Ivory Coast (12), Mali (5), Niger (3) participated in this survey which gives an insight into the daily hygiene routines of these services. The cleaning, decontamination, disinfection and sterilization procedures for premises, dental equipment, instruments, hands and disposable items were investigated. No individual protocols are reported. Bench tops were cleaned or disinfected daily in 73% of centers and floors were cleaned or disinfected daily in 59% of centers. Walls were cleaned once per week in 44% of the centers. Hands were always washed between patients, with 68% of dental surgeons using only solid or liquid cleansing soaps and the others using antiseptic or disinfectant solutions. The dentist's chair was cleaned or disinfected daily in 68% of centers, mostly with soap (43%) or diluted bleach (23%). Vacuum equipment was cleaned with soap (50%) or diluted bleach (57%), with some surgeries using a combination of the two. Hand pieces and turbines were cleaned and disinfected after each use with alcohol (35%) or diluted bleach (26%) and were sterilized in 9% of centers. Instruments were sterilized with a Poupinel (63%), unspecified sterilizer (26%), autoclave (7%) or low temperature disinfection procedure (4%). Instruments were regularly sterilized in all centers. Single-use disposable items were often reused: 88% of centers reused gloves, 64% anesthetic cartridges and 32% disposable needles. This survey demonstrates that dentists do attempt to achieve appropriate

  12. Liquid Methane Conditioning Capabilities Developed at the NASA Glenn Research Center's Small Multi- Purpose Research Facility (SMiRF) for Accelerated Lunar Surface Storage Thermal Testing

    NASA Technical Reports Server (NTRS)

    Bamberger, Helmut H.; Robinson, R. Craig; Jurns, John M.; Grasl, Steven J.

    2011-01-01

    Glenn Research Center s Creek Road Cryogenic Complex, Small Multi-Purpose Research Facility (SMiRF) recently completed validation / checkout testing of a new liquid methane delivery system and liquid methane (LCH4) conditioning system. Facility checkout validation was conducted in preparation for a series of passive thermal control technology tests planned at SMiRF in FY10 using a flight-like propellant tank at simulated thermal environments from 140 to 350K. These tests will validate models and provide high quality data to support consideration of LCH4/LO2 propellant combination option for a lunar or planetary ascent stage.An infrastructure has been put in place which will support testing of large amounts of liquid methane at SMiRF. Extensive modifications were made to the test facility s existing liquid hydrogen system for compatibility with liquid methane. Also, a new liquid methane fluid conditioning system will enable liquid methane to be quickly densified (sub-cooled below normal boiling point) and to be quickly reheated to saturation conditions between 92 and 140 K. Fluid temperatures can be quickly adjusted to compress the overall test duration. A detailed trade study was conducted to determine an appropriate technique to liquid conditioning with regard to the SMiRF facility s existing infrastructure. In addition, a completely new roadable dewar has been procured for transportation and temporary storage of liquid methane. A new spherical, flight-representative tank has also been fabricated for integration into the vacuum chamber at SMiRF. The addition of this system to SMiRF marks the first time a large-scale liquid methane propellant test capability has been realized at Glenn.This work supports the Cryogenic Fluid Management Project being conducted under the auspices of the Exploration Technology Development Program, providing focused cryogenic fluid management technology efforts to support NASA s future robotic or human exploration missions.

  13. TH-A-19A-08: Intel Xeon Phi Implementation of a Fast Multi-Purpose Monte Carlo Simulation for Proton Therapy

    SciTech Connect

    Souris, K; Lee, J; Sterpin, E

    2014-06-15

    Purpose: Recent studies have demonstrated the capability of graphics processing units (GPUs) to compute dose distributions using Monte Carlo (MC) methods within clinical time constraints. However, GPUs have a rigid vectorial architecture that favors the implementation of simplified particle transport algorithms, adapted to specific tasks. Our new, fast, and multipurpose MC code, named MCsquare, runs on Intel Xeon Phi coprocessors. This technology offers 60 independent cores, and therefore more flexibility to implement fast and yet generic MC functionalities, such as prompt gamma simulations. Methods: MCsquare implements several models and hence allows users to make their own tradeoff between speed and accuracy. A 200 MeV proton beam is simulated in a heterogeneous phantom using Geant4 and two configurations of MCsquare. The first one is the most conservative and accurate. The method of fictitious interactions handles the interfaces and secondary charged particles emitted in nuclear interactions are fully simulated. The second, faster configuration simplifies interface crossings and simulates only secondary protons after nuclear interaction events. Integral depth-dose and transversal profiles are compared to those of Geant4. Moreover, the production profile of prompt gammas is compared to PENH results. Results: Integral depth dose and transversal profiles computed by MCsquare and Geant4 are within 3%. The production of secondaries from nuclear interactions is slightly inaccurate at interfaces for the fastest configuration of MCsquare but this is unlikely to have any clinical impact. The computation time varies between 90 seconds for the most conservative settings to merely 59 seconds in the fastest configuration. Finally prompt gamma profiles are also in very good agreement with PENH results. Conclusion: Our new, fast, and multi-purpose Monte Carlo code simulates prompt gammas and calculates dose distributions in less than a minute, which complies with clinical time

  14. Disinfection of Contaminated Canals by Different Laser Wavelengths, while Performing Root Canal Therapy.

    PubMed

    Asnaashari, Mohammad; Safavi, Nassimeh

    2013-01-01

    Removal of smear layer and disinfection of canals are important objectives of teeth root canal cleaning. In order to achieve this purpose, rinsing substances, intra canal drugs as well as ultrasound are used. Today, use of laser to remove smear layer and to disinfect root canals has increasingly attracted the attentions. Till now different lasers such as CO2, Nd:YAG, Er:YAG, Er,Cr:YSGG have been used for debris and smear removal from the canals. Numerous studies have shown that Er:YAG is the most appropriate laser for intra canal debris and smear removal. In addition different laser wavelengths have been used directly or as an adjunctive to disinfect canals. Laser light can penetrate areas of canals where irrigating and disinfecting solutions cannot reach, like secondary canals and deep dentinal tubules and also can eliminate microorganisms. Different studies have confirmed the penetration of Nd:YAG laser in deep dentin and reduction of microorganisms penetration. But studies on comparison of antibacterial effects of Nd:YAG laser with sodium hypochlorite showed effectiveness of both, with a better effect for sodium hypochlorite. Studies performed in relation with anti-microbial effects of Diode laser with various parameters show that this laser can be effective in reducing intra canal bacterial count and penetration in the depth of 500 microns in dentin. In studies performed on Diode laser in combination with canal irrigating solutions such as sodium hypochlorite and oxygenated water better results were obtained. Although studies on disinfection by the Erbium laser family show that use of this laser alone can be effective in disinfecting canals, studies evaluating the disinfecting effects of this laser and different concentrations of sodium hypochlorite show that the latter alone is more effective in disinfecting canals. And better results were obtained when Erbium laser was used in combination with sodium hypochlorite irrigating solution in canals. Results of the

  15. Disinfecting efficacy of three chemical disinfectants on contaminated diagnostic instruments: A randomized trial

    PubMed Central

    Ganavadiya, Rahul; Chandra Shekar, B.R.; Saxena, Vrinda; Tomar, Poonam; Gupta, Ruchika; Khandelwal, Garima

    2014-01-01

    Context: Cross infection remains one of the major challenges in the dental profession, especially in field settings. Transmission of hepatitis B, hepatitis C, and human immunodeficiency virus have raised a major concern for patients and dental staff. These risks can be eliminated by effective sterilization and disinfection techniques. Aim: The aim was to compare the disinfecting efficacy of three chemical disinfectants on contaminated diagnostic instruments. Settings and Design: This was a randomized, cross over trial conducted among three participants selected from a research laboratory, Bhopal, Madhya Pradesh, India. Materials and Methods: The study participants were examined 4 times on different days. Each time, the coded mouth mirrors of different make were used, and the disinfection was accomplished using coded disinfectants. The reduction in total viable count was compared between the three groups (2% glutaraldehyde, 6% hydrogen peroxide (H2O2) and 99.9% ethyl alcohol) with distilled water as negative control and autoclaving as a positive control. Furthermore, the predisinfection count was compared between the instruments of different make. Statistical Analysis Used: Statistical analysis was performed using paired t-test and One-way ANOVA. The statistical significance was fixed at 0.05. Results: Autoclaved instruments resulted in complete elimination of viable micro-organisms. Maximum reduction in microbial load was observed after disinfection with H2O2 followed by glutaraldehyde, ethyl alcohol and distilled water in descending order. Furthermore, maximum microbial contamination was recorded on locally manufactured mirrors, while standard plain mirrors showed least contamination. Conclusions: Although, a significant reduction in total viable count was observed with all the disinfectants evaluated in the present study, none of the disinfectants was successful in completely eliminating the viable micro-organisms. PMID:25316989

  16. Efficacy of Various Chemical Disinfectants on Biofilms Formed in Spacecraft Potable Water System Component

    NASA Technical Reports Server (NTRS)

    Wong, Willy; Garcia, Veronica; Castro, Victoria; Ott, Mark; Duane

    2009-01-01

    As the provision of potable water is critical for successful habitation of the International Space Station (ISS), life support systems were installed in December 2008 to recycle both humidity from the atmosphere and urine to conserve available water in the vehicle. Pre-consumption testing from the dispensing needle at the Potable Water Dispenser (PWD) indicated that bacterial concentrations exceeded the current ISS specifications of 50 colony forming units (CFU) per ml. Subsequent investigations revealed that a corrugated stainless steel flex hose upstream of the dispensing needle in the PWD was filled with non-sterile water and left at room temperature for over one month before launch. To simulate biofilm formation that was suspected in the flight system, sterile flex hoses were seeded with a consortium of bacterial isolates previously recovered from other ISS water systems, which included Ralstonia pickettii, Burkholderia multivorans, Caulobacter vibrioides., and Cupriavidus pauculus. After 5 days of incubation, these hoses were challenged with various chemical disinfectants including hydrogen peroxide, colloidal silver, and buffered pH solutions to determine the ability of the disinfectants to decrease and maintain bacterial concentrations below ISS specifications. Disinfection efficacy over time was measured by collecting daily heterotrophic plate counts following exposure to the disinfectants. A single flush with either 6% hydrogen peroxide solution or a mixture of 3% hydrogen peroxide and 400 ppb colloidal silver effectively reduced the bacterial concentrations to less than 1 CFU/ml for a period of up to 2 months. Testing results indicated that hydrogen peroxide and mixtures of hydrogen peroxide and colloidal silver have tremendous potential as alternative disinfectants for ISS water systems.

  17. Effective disinfection methods of kitchen sponges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pathogenic foodborne bacteria can be disseminated in households through the use of contaminated sponges. Several household disinfecting treatments to kill bacteria, yeasts and molds on sponges were evaluated. Sponges were incubated in a suspension of ground beef and tryptic soy broth to develop bact...

  18. USE OF FENTON'S REAGENT AS A DISINFECTANT

    EPA Science Inventory

    Combined sewage samples obtained from a wastewater treatment facility were disinfected by the Fenton's Reagent of several different compositions. The pre-settled samples contained both suspended solids (SS) and dissolved organic carbon (DOC) at concentrations of 28 and 290 mg/L,...

  19. 40 CFR 141.72 - Disinfection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... serves water to the public. Water in the distribution system with a heterotrophic bacteria concentration... heterotrophic bacteria plate count (HPC) is measured; c=number of instances where the residual disinfectant... system with a heterotrophic bacteria concentration less than or equal to 500/ml, measured...

  20. 40 CFR 141.72 - Disinfection.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... serves water to the public. Water in the distribution system with a heterotrophic bacteria concentration... heterotrophic bacteria plate count (HPC) is measured; c=number of instances where the residual disinfectant... system with a heterotrophic bacteria concentration less than or equal to 500/ml, measured...

  1. DISINFECTION AND THE CONTROL OF WATERBORNE GIARDIASIS

    EPA Science Inventory

    In the early 1970's, when giardiasis began to be recognized as an important waterborne disease, the understanding of the effects of disinfectants on the cysts of the etiologic agent, Giardia lamblia, was extremely limited. The results of more recent studies, using improved method...

  2. DISINFECTION: CHLORINE, MONOCHLORAMINE, AND CHLORINE DIOXIDE

    EPA Science Inventory

    The disinfection process in the treatment of water is designed to insure the inactivation of microbial pathogens. These pathogens which serve as the etiological agents of waterborne disease comprise a diverse group of microorganisms, which include bacterial, viral and protozoan s...

  3. Effective household disinfection methods of kitchen sponges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several household disinfecting treatments to kill bacteria, yeasts and molds on kitchen sponges were evaluated. Sponges were soaked in 10 percent bleach for 3 min, lemon juice (pH 2.9) or deionized water for 1 min; placed in a microwave oven for 1 min; or placed in a dishwasher operating with a dryi...

  4. 40 CFR 141.72 - Disinfection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... treatment must be sufficient to ensure at least 99.9 percent (3-log) inactivation of Giardia lamblia cysts... for Giardia lamblia cysts and viruses. If a system uses a disinfectant other than chlorine, the system....9 percent (3-log) inactivation and/or removal of Giardia lamblia cysts and at least 99.99 percent...

  5. [The effect of a single disinfection of a farm on cryptosporidiosis infection in calves].

    PubMed

    Pavlásek, I; Mares, J

    1983-08-01

    The disinfection of a farm with Dikonit (active substance: sodium dichlorocyanuran) exerted no significant influence on the course of the spreading of cryptosporidiosis infections in newborn calves. The oocysts of Cryptosporidium sp., isolated from the faeces of a spontaneously infected calf and left in a 2.5% disinfecting solution of Dikonit under laboratory conditions for four hours, did not lose their viability. Laboratory mice experimentally infected with these "disinfected" oocysts, began to produce oocysts of Cryptosporidium sp. the sixth day from infection. The findings of different developmental stages of this protozoan obtained during the histological examination of the intestinal tissue of test mice are also considered as evidence of successful experimental infection. The cryptosporidium-free period which lasted only 14 days from disinfection was mainly due to thorough mechanical cleaning of the area where the calves were kept after birth. This is also proved by the results of the examination of old residues of calf faeces scraped from the floors: only individual individual oocysts of Cryptosporidium sp. were found in these samples. PMID:6414147

  6. [Endodontics in motion: new concepts, materials and techniques 4. Root canal disinfection in 2015].

    PubMed

    van der Waal, S V; de Soet, J J

    2015-12-01

    Apical periodontitis is an inflammatory response around the root tip of a tooth to microbial infection of the root canal system. Therefore, disinfection of the root canal system is the most important aim of root canal treatment. There are various mechanical and chemical ways to clean and disinfect. Most methods, however, cannot be relied upon to fully decontaminate in all cases. There are problems, for example, with the proper concentrations of disinfectant agents, like sodium hypochlorite. But the more recent agents, like ethylenediaminetetraacetic acid, calcium hydroxide or antibiotic pastes also have disadvantages, which are mostly a result of poor access of the irrigant to the biofilm bacteria in the affected root canals. Currently, a new strategy with a modified salt solution is under investigation that offers the prospect of being used as a root canal irrigant. At this moment the preferred treatment still seems to be to remove infected tissue as much as possible and to create access for irrigation procedures. The best results are achieved with 1-2% sodium hypochlorite as a disinfectant, possibly alternating with ethylenediaminetetraacetic acid as a cleansing agent. There is no scientific evidence for the successful use of calcium hydroxide. PMID:26665204

  7. Efficacy of three surface disinfectants for dental radiographic films and gloves.

    PubMed

    Coogan, M M; Patel, M; Mladenova, D

    2004-07-01

    Contaminated radiographic films and gloves may transmit infectious diseases. Objective. To determine whether Pre Sept (NaDC), a sodium dichloroisocyanurate based disinfectant; Bronocide SP (AIP) an alcohol-phenol-iodine disinfectant and polyvinyl pyrrolidine iodine (PVPI) can be used to disinfect radiographic films and gloves. Study design. Radiographic films were contaminated with Candida albicans, Streptococcus mutans, Lactobacilli or saliva and placed in either 0.1, 0.25 or 0.5 NaDC for 1, 2 or 5 min; PVPI for 5 min or sprayed with AIP. Gloves contaminated with C. albicans, S. mutans or Lactobacilli were sprayed with AIP. After treatment the films and gloves were tested for viable microorganisms. Results. A 0.5% solution of NaDC killed all microorganisms after one-minute exposure. PVPI killed 99.8% and AIP spray between 95.8 and 99% of microorganisms. Conclusions. NaDC was the most successful disinfectant in the laboratory and clinical setting followed by PVPI and AIP. PMID:15193787

  8. Surface disinfection procedure and in vitro regeneration of grapevine (Vitis vinifera L.) axillary buds.

    PubMed

    Lazo-Javalera, M F; Troncoso-Rojas, R; Tiznado-Hernández, M E; Martínez-Tellez, M A; Vargas-Arispuro, I; Islas-Osuna, M A; Rivera-Domínguez, M

    2016-01-01

    Establishment of an efficient explants surface disinfection protocol is essential for in vitro cell and tissue culture as well as germplasm conservation, such as the case of Grapevine (Vitis spp.) culture. In this research, different procedures for disinfection and regeneration of field-grown grapevine cv. 'Flame seedless' axillary buds were evaluated. The buds were disinfected using either NaOCl or allyl, benzyl, phenyl and 2-phenylethyl isothiocyanates. Two different media for shooting and four media for rooting were tested. Shoot and root development per buds were registered. The best disinfection procedure with 90 % of tissue survival involved shaking for 60 min in a solution containing 20 % Clorox with 50 drops/L Triton(®) X-100. These tissues showed the potential to regenerate a complete plant. Plant regeneration was conducted using full strength Murashigue and Skoog (MS) medium supplemented with 8 µM benzyl aminopurine for shoot induction and multiplication, whereas rooting was obtained on half strength MS supplemented with 2 mg L(-1) of indole-3-butyric acid and 200 mg L(-1) of activated charcoal. In this work, it was designed the protocols for obtaining sterile field-grown grapevine buds and in vitro plant development. This methodology showed potential to produce vigorous and healthy plants in 5 weeks for clonal grapevine propagation. Regenerated plants were successfully established in soil. PMID:27119057

  9. 40 CFR 141.541 - What are significant changes to disinfection practice?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Disinfection Benchmark § 141.541 What are significant... point of disinfection; (b) Changes to the disinfectant(s) used in the treatment plant; (c) Changes...

  10. Peracetic acid for secondary effluent disinfection: a comprehensive performance assessment.

    PubMed

    Antonelli, M; Turolla, A; Mezzanotte, V; Nurizzo, C

    2013-01-01

    The paper is a review of previous research on secondary effluent disinfection by peracetic acid (PAA) integrated with new data about the effect of a preliminary flash-mixing step. The process was studied at bench and pilot scale to assess its performance for discharge in surface water and agricultural reuse (target microorganisms: Escherichia coli and faecal coliform bacteria). The purposes of the research were: (1) determining PAA decay and disinfection kinetics as a function of operating parameters, (2) evaluating PAA suitability as a disinfectant, (3) assessing long-term disinfection efficiency, (4) investigating disinfected effluent biological toxicity on some aquatic indicator organisms (Vibrio fischeri, Daphnia magna and Selenastrum capricornutum), (5) comparing PAA with conventional disinfectants (sodium hypochlorite, UV irradiation). PAA disinfection was capable of complying with Italian regulations on reuse (10 CFU/100 mL for E. coli) and was competitive with benchmarks. No regrowth phenomena were observed, as long as needed for agricultural reuse (29 h after disinfection), even at negligible concentrations of residual disinfectant. The toxic effect of PAA on the aquatic environment was due to the residual disinfectant in the water, rather than to chemical modification of the effluent. PMID:24355852

  11. SMALL DRINKING WATER SYSTEMS HANDBOOK A GUIDE TO "PACKAGED" FILTRATION AND DISINFECTION TECHNOLOGIES WITH REMOTE MONITORING AND CONTROL TOOLS

    EPA Science Inventory

    The intent of this handbook is to highlight information appropriate to small systems with an emphasis on filtration and disinfection technologies and how they can be "packaged" with remote monitoring and control technologies to provide a healthy and affordable solution for small ...

  12. Effect of a disinfectant udder wash and a post-milking teat dip on the bacterial population of the teat end and on the rate of new intramammary infection.

    PubMed

    Sheldrake, R F; Hoare, R J

    1980-10-01

    A pre-milking wash disinfectant procedure employing a 2% (w/v) chlorhexidine solution in a detergent basic did not reduce the rate of new intramammary infection in a lactating herd challenged with Staphylococcus aureus. Teat-end swabs showed no significant difference in the number of Staph. aureus isolated from the teat-ends pre-washed with either water, or water and chlorhexidine. In contrast, disinfecting teats after milking with a solution containing 5000 mg available iodine/l significantly reduced the staphylococcal population of the teat-ends and the rate of new intramammary infection, compared with teats not disinfected. PMID:7451707

  13. Assessment of an innovative antimicrobial surface disinfectant in the operating room environment using adenosine triphosphate bioluminescence assay.

    PubMed

    Lewis, Brian D; Spencer, Maureen; Rossi, Peter J; Lee, Cheong J; Brown, Kellie R; Malinowski, Michael; Seabrook, Gary R; Edmiston, Charles E

    2015-03-01

    Terminal cleaning in the operating room is a critical step in preventing the transmission of health care-associated pathogens. The persistent disinfectant activity of a novel isopropyl alcohol/organofunctional silane solution (ISO) was evaluated in 4 operating rooms after terminal cleaning. Adenosine triphosphate bioluminescence documented a significant difference (P < .048) in surface bioburden on IOS-treated surfaces versus controls. RODAC plate cultures revealed a significant (P < .001) reduction in microbial contamination on IOS-treated surfaces compared with controls. Further studies are warranted to validate the persistent disinfectant activity of ISO within selective health care settings. PMID:25728155

  14. Comparison of UVB and UVC irradiation disinfection efficacies on Pseudomonas Aeruginosa (P. aeruginosa) biofilm

    NASA Astrophysics Data System (ADS)

    Argyraki, A.; Markvart, M.; Nielsen, Anne; Bjarnsholt, T.; Bjørndal, L.; Petersen, P. M.

    2016-04-01

    Disinfection routines are important in all clinical applications. The uprising problem of antibiotic resistance has driven major research efforts towards alternative disinfection approaches, involving light-based solutions. Pseudomonas aeruginosa (P. aeruginosa) is a common bacterium that can cause skin, soft tissue, lungs, kidney and urinary tract infections. Moreover, it can be found on and in medical equipment causing often cross infections in hospitals. The objective of this study was to test the efficiency, of two different light-based disinfection treatments, namely UVB and UVC irradiation, on P. aeruginosa biofilms at different growth stages. In our experiments a new type of UV light emitting diodes (LEDs) were used to deliver UV irradiation on the biofilms, in the UVB (296nm) and UVC (266nm) region. The killing rate was studied as a function of dose for 24h grown biofilms. The dose was ramped from 72J/m2 to 10000J/m2. It was shown that UVB irradiation was more effective than UVC irradiation in inactivating P. aeruginosa biofilms. No colony forming units (CFU) were observed for the UVB treated biofilms when the dose was 10000 J/m2 (CFU in control sample: 7.5 x 104). UVB irradiation at a dose of 20000J/m2 on mature biofilms (72h grown) resulted in a 3.9 log killing efficacy. The fact that the wavelength of 296nm exists in daylight and has such disinfection ability on biofilms gives new perspectives for applications within disinfection at hospitals.

  15. Effect of magnetic ion exchange and ozonation on disinfection by-product formation.

    PubMed

    Kingsbury, Ryan S; Singer, Philip C

    2013-03-01

    The purpose of this research was to investigate the performance of treatment with magnetic ion exchange (MIEX) resin followed by ozonation in achieving disinfection goals while controlling bromate and chlorinated disinfection by-product (DBP) formation. Three water samples were collected from raw water supplies impacted by the San Francisco Bay Delta to represent the varying levels of bromide and total organic carbon (TOC) that occur throughout the year. A fourth water was prepared by spiking bromide into a portion of one of the samples. Samples of each water were pre-treated with alum or virgin MIEX resin, and the raw and treated waters were subsequently ozonated under semi-batch conditions to assess the impact of treatment on ozone demand, ozone exposure for disinfection ("CT"), and bromate formation. Finally, aliquots of raw, coagulated, resin-treated, and ozonated waters were chlorinated in order to measure trihalomethane formation potential (THMFP). In the waters studied, MIEX resin removed 41-68% of raw water TOC, compared to 12-44% for alum. MIEX resin also reduced the bromide concentration by 20-50%. The removal of TOC by alum and MIEX resin significantly reduced the ozone demand of all waters studied, resulting in higher dissolved ozone concentrations and CT values for a given amount of ozone transferred into solution. For a given level of disinfection (CT), the amount of bromate produced by ozonation of MIEX-treated waters was similar to or slightly less than that of raw water and significantly less than that of alum-treated water. MIEX resin removed 39-85% of THMFP compared to 16-56% removal by alum. Ozonation reduced THMFP by 35-45% in all cases. This work indicates that in bromide-rich waters in which ozone disinfection is used, MIEX resin is a more appropriate treatment than alum for the removal of organic carbon, as it achieves superior TOC and THM precursor removal and decreases the production of bromate from ozone. PMID:23286989

  16. Solar-photocatalytic disinfection of Vibrio cholerae by using Ag@ZnO core-shell structure nanocomposites.

    PubMed

    Das, Sourav; Sinha, Sayantan; Suar, Mrutyunjay; Yun, Soon-Il; Mishra, Amrita; Tripathy, Suraj K

    2015-01-01

    Disinfection of Gram-negative bacterium Vibrio cholerae 569B in aqueous matrix by solar-photocatalysis mediated by Ag@ZnO core-shell structure nanocomposite particles was investigated. Silver nanoparticles are synthesized by the reduction of silver perchlorate followed by precipitation of zinc oxide shell and are employed in the photocatalytic disinfection of the model pathogen. Effect of photocatalyst loading and reaction temperature on the disinfection kinetics was studied. Disinfection efficiency in laboratory as well as real water samples was compared with that of pure-ZnO and TiO2 (Degussa P25). Nanocomposite system has shown optimum disinfection (≈98%) at 40-60min of sun-light exposure with a catalyst loading of 0.5mg/L of the reaction solution. The reduction of aquatic bacterial densities by photocatalytically active Ag@ZnO core-shell nanocomposite in presence of natural sun-light may have potential ex situ application in water decontamination at ambient conditions. PMID:25523714

  17. Comparison of the efficacy of natural-based and synthetic biocides to disinfect silicone and stainless steel surfaces.

    PubMed

    Gomes, I B; Malheiro, J; Mergulhão, F; Maillard, J-Y; Simões, M

    2016-06-01

    New biocidal solutions are needed to combat effectively the evolution of microbes developing antibiotic resistance while having a low or no environmental toxicity impact. This work aims to assess the efficacy of commonly used biocides and natural-based compounds on the disinfection of silicone and stainless steel (SS) surfaces seeded with differentStaphylococcus aureusstrains. Minimum inhibitory concentration was determined for synthetic (benzalkonium chloride-BAC, glutaraldehyde-GTA,ortho-phthalaldehyde-OPA and peracetic acid-PAA) and natural-based (cuminaldehyde-CUM), eugenol-EUG and indole-3-carbinol-I3C) biocides by the microdilution method. The efficacy of selected biocides at MIC, 10 × MIC and 5500 mg/L (representative in-use concentration) on the disinfection of sessileS. aureuson silicone and SS was assessed by viable counting. Silicone surfaces were harder to disinfect than SS. GTA, OPA and PAA yielded complete CFU reduction of sessile cells for all test concentrations as well as BAC at 10 × MIC and 5500 mg/L. CUM was the least efficient compound. EUG was efficient for SS disinfection, regardless of strains and concentrations tested. I3C at 10 × MIC and 5500 mg/L was able to cause total CFU reduction of silicone and SS deposited bacteria. Although not so efficient as synthetic compounds, the natural-based biocides are promising to be used in disinfectant formulations, particularly I3C and EUG. PMID:26926153

  18. Reaction of silver nanoparticles in the disinfection process.

    PubMed

    Yuan, Zhihua; Chen, Yunbin; Li, Tingting; Yu, Chang-Ping

    2013-10-01

    This study investigated the dissolution, aggregation, and reaction kinetics of silver nanoparticles (AgNPs) with the three types of water disinfectants (ultraviolet, sodium hypochlorite, and ozone) under the different conditions of pH, ionic strength, or humic acid (HA). The physicochemical changes of AgNPs were measured by using UV-Vis spectroscopy, transmission electron microscopy, and inductively coupled plasma optical emission spectrometer. The results showed that when AgNPs contacted the disinfectants, oxidative dissolution was the primary reaction. In addition, the reaction kinetics studies revealed that the reaction rate of AgNPs with disinfectants was significantly influenced by different disinfectants along with different pH and the presence of sodium nitrate and HA. Our research demonstrated the potential effect of disinfectants on AgNPs, which will improve our understanding of the fate of AgNPs in the disinfection processes in the water and wastewater treatment plant. PMID:23830116

  19. Lighting the way to improved disinfection

    SciTech Connect

    Valenti, M.

    1997-07-01

    Ultraviolet light has a proven track record of killing bacteria and viruses found in municipal wastewater. In addition, environmental concerns over the use of chemical disinfectants, coupled with improvements in ultraviolet-lighting technology, have led to the development of UV systems that treat spent metalworking fluids in the industrialized world; disinfect drinking water in developing countries; and clean aquaculture water, ballast water, and hospital air everywhere. A large-scale pilot plant capable of treating less than 1 million gallons per day was built on-site by Los Angeles-based Montgomery Watson and CCCSD in 1992. It demonstrated that UV was just as effective as chlorination in killing bacteria and slightly more effective in destroying viruses found in the Martinez plant`s wastewater. It also showed the lamps would need to be cleaned of fouling every two to four weeks. The paper discusses this plant and the use of UV light in the above-mentioned water treatment processes.

  20. Disinfectants for spacecraft applications - An overview

    NASA Technical Reports Server (NTRS)

    Koenig, David W.; Mallary, Laura L.; Pierson, Duane L.

    1991-01-01

    The review of disinfectants for use on manned missions emphasizes the need for contamination control to prevent the detrimental effects of bacteria growth on crew health. Microbial control is possible by means of biocides, but the selected product has to meet stringent toxicity requirements for the small environments in spacecraft. The testing and evaluation is described of four biocide candidates: hydrogen peroxide, quaternary ammonium compounds, iodine, and glutaraldehyde. The effectiveness of the disinfectants are analyzed in terms of the ability to treat typical microbial counts from Skylab missions in a closed environment. It is shown that many biocide candidates are not compatible with the ECLSS, water-recovery management, and air-revitalization subsystems of the Space Station Freedom. The use of hydrogen peroxide is proposed with a secondary stronger agent for microbial spills from biological experiments.

  1. Research Issues Underlying the Four-Lab Study: Integrated Disinfection Byproducts Mixtures Research

    EPA Science Inventory

    Chemical disinfection of drinking water is a major public health triumph of the 20th century, resulting in significant decreases in morbidity and mortality from waterborne diseases. Disinfection byproducts (DBPs) are chemicals formed by the reaction of oxidizing disinfectants wi...

  2. 9 CFR 85.12 - Cleaning and disinfecting means of conveyance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... disinfected in accordance with § 71.7 of this chapter using one of the disinfectants registered under the... virucidal claims. These disinfectants shall be used in accordance with directions on their labels...

  3. 9 CFR 85.12 - Cleaning and disinfecting means of conveyance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... disinfected in accordance with § 71.7 of this chapter using one of the disinfectants registered under the... virucidal claims. These disinfectants shall be used in accordance with directions on their labels...

  4. 9 CFR 85.12 - Cleaning and disinfecting means of conveyance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... disinfected in accordance with § 71.7 of this chapter using one of the disinfectants registered under the... virucidal claims. These disinfectants shall be used in accordance with directions on their labels...

  5. 9 CFR 85.12 - Cleaning and disinfecting means of conveyance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... disinfected in accordance with § 71.7 of this chapter using one of the disinfectants registered under the... virucidal claims. These disinfectants shall be used in accordance with directions on their labels...

  6. 9 CFR 85.12 - Cleaning and disinfecting means of conveyance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... disinfected in accordance with § 71.7 of this chapter using one of the disinfectants registered under the... virucidal claims. These disinfectants shall be used in accordance with directions on their labels...

  7. Silver-based Antibacterial Surfaces for Drinking Water Disinfection - An overview

    EPA Science Inventory

    Risks associated with current disinfection techniques, including the formation of disinfection by-products and multi-drug resistant bacterial species, have prompted the exploration of advanced disinfection methods. One such technique employs silver nanoparticles incorporation on ...

  8. THE UPTAKE OF WATER DISINFECTION BY-PRODUCTS INTO FOODS DURING HOME PROCESSING

    EPA Science Inventory

    A variety of organic compounds in tap water are produced as a result of disinfection process. Use of chlorine-containing chemicals for disinfection produces many disinfection by-products (DBPs) including trihalomethanes, haloacetonitriles and haloacetic acid. Ozonation with secon...

  9. Experience in Remote Demolition of the Activated Biological Shielding of the Multi Purpose Research Reactor (MZFR) on the German Karlsruhe Site - 12208

    SciTech Connect

    Eisenmann, Beata; Fleisch, Joachim; Prechtl, Erwin; Suessdorf, Werner; Urban, Manfred

    2012-07-01

    In 2009, WAK Decommissioning and Waste Management GmbH (WAK) became owner and operator of the waste treatment facilities of Karlsruhe Institute of Technology (KIT) as well as of the prototype reactors, the Compact Sodium-Cooled Fast Reactor (KNK) and Multi-Purpose Reactor (MZFR), both being in an advanced stage of dismantling. Together with the dismantling and decontamination activities of the former WAK reprocessing facility since 1990, the envisaged demolishing of the R and D reactor FR2 and a hot cell facility, all governmentally funded nuclear decommissioning projects on the Karlsruhe site are concentrated under the WAK management. The small space typical of prototype research reactors represented a challenge also during the last phase of activated dismantling, dismantling of the activated biological shield of the MZFR. Successful demolition of the biological shield required detailed planning and extensive testing in the years before. In view of the limited space and the ambient dose rate that was too high for manual work, it was required to find a tool carrier system to take up and control various demolition and dismantling tools in a remote manner. The strategy formulated in the concept of dismantling the biological shield by means of a modified electro-hydraulic demolition excavator in an adaptable working scaffolding turned out to be feasible. The following boundary conditions were essential: - Remote exchange of the dismantling and removal tools in smallest space. - Positioning of various supply facilities on the working platform. - Avoiding of interfering edges. - Optimization of mass flow (removal of the dismantled mass from the working area). - Maintenance in the surroundings of the dismantling area (in the controlled area). - Testing and qualification of the facilities and training of the staff. Both the dismantling technique chosen and the proceeding selected proved to be successful. Using various designs of universal cutters developed on the basis of

  10. Regenerable Iodine Water-Disinfection System

    NASA Technical Reports Server (NTRS)

    Sauer, Richard L.; Colombo, Gerald V.; Jolly, Clifford D.

    1994-01-01

    Iodinated resin bed for disinfecting water regenerated to extend useful life. Water flows through regeneration bed of crystalline iodine during regeneration. At other times, flow diverted around regeneration bed. Although regeneration cycle manually controlled readily automated to start and stop according to signals from concentration sensors. Further benefit of regeneration is bed provides highly concentrated biocide source when needed. Concentrated biocide used to superiodinate system after contamination from routine maintenance or unexpected introduction of large concentration of microbes.

  11. Disinfection of secondary effluents by infiltration percolation.

    PubMed

    Makni, H

    2001-01-01

    Among the most attractive applications of reclaimed wastewater are: irrigation of public parks, sports fields, golf courses and market gardening. These uses require advanced wastewater treatment including disinfection. According to WHO guidelines (1989) and current rules and regulations in Tunisia, faecal coliform levels have to be reduced to < 10(3) or 10(2) CFU/100 mL. In Tunisia, most wastewater plants are only secondary treatment and, in order to meet health related regulations, the effluents need to be disinfected. However, it is usual for secondary effluents to need filtration prior to disinfection. Effectiveness of conventional disinfection processes, such as chlorination and UV radiation, are dependent upon the oxidation level and the levels of suspended solids of the treated water. Ozonation is relatively expensive and energy consuming. The consideration of the advantages and disadvantages of conventional techniques, their reliability, investment needs and operational costs will lead to the use of less sophisticated alternative techniques for certain facilities. Among alternative techniques, soil aquifer treatment and infiltration percolation through sand beds have been studied in Arizona, Israel, France, Spain and Morocco. Infiltration percolation plants have been intermittently fed with secondary or high quality primary effluents which percolated through 1.5-2 m unsaturated coarse sand and were recovered by under-drains. In such infiltration percolation facilities, microorganisms were eliminated through numerous physical, physicochemical and biological inter-related processes (mechanical filtration, adsorption and microbial degradation respectively). Efficiency of faecal coliform removal was dependent upon the water detention times in the filtering medium and on the oxidation of the filtered water. Effluents of Sfax town aerated ponds were infiltrated through 1.5 m deep sand columns in order to determine the performance of infiltration percolation in the

  12. Influence of ultrasound enhancement on chlorine dioxide consumption and disinfection by-products formation for secondary effluents disinfection.

    PubMed

    Zhou, Xiaoqin; Zhao, Junyuan; Li, Zifu; Lan, Juanru; Li, Yajie; Yang, Xin; Wang, Dongling

    2016-01-01

    Chlorine dioxide (ClO2) has been promoted as an alternative disinfectant because of its high disinfection efficiency and less formation of organic disinfection by-products (DBPs). However, particle-associated microorganisms could be protected during the disinfection process, which decreases the disinfection efficiency or increases the required dosage. Besides, the formation of inorganic disinfection by-products is a significant concern in environment health. Ultrasound (US)-combined disinfection methods are becoming increasingly attractive because they are efficient and environmentally friendly. In this study, US was introduced as an enhancement method to identify its influence on ClO2 demand reduction and to minimize the production of potential DBPs for secondary effluents disinfection. Fecal coliform was used as an indicator, and DBPs, including trichloromethane (TCM), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), chlorite (ClO2(-)), and chlorate (ClO3(-)), were analyzed to observe the potential DBPs formation. Results show that US pretreatment could reduce half of ClO2 dosage compared with ClO2 disinfection alone for the same disinfection efficiency, and that an input power density of 2.64 kJ/L pretreatment with the 1.5mg/L ClO2 was enough to meet the discharge requirement in China (i.e., fecal coliform below 1000 CFU/L for Class 1A) for secondary effluent disinfection, and the ClO2(-) concentration in the disinfection effluent was only 1.37 mg/L at the same time. Furthermore, the different effects of US on the two processes (US as pretreatment and simultaneous US/ClO2 disinfection) were also analyzed, including deagglomerating, cell damage, and synergistic disinfection as well as degasing/sonolysis. It was proved that the production of TCM, DCAA, and TCAA was insignificantly influenced with the introduction of US, but US pretreatment did reduce the production of ClO2(-) and ClO3(-) effectually. In general, US pretreatment could be a better option for

  13. Evaluation of toothbrush disinfection via different methods.

    PubMed

    Basman, Adil; Peker, Ilkay; Akca, Gulcin; Alkurt, Meryem Toraman; Sarikir, Cigdem; Celik, Irem

    2016-01-01

    The aim of this study was to compare the efficacy of using a dishwasher or different chemical agents, including 0.12% chlorhexidine gluconate, 2% sodium hypochlorite (NaOCl), a mouthrinse containing essential oils and alcohol, and 50% white vinegar, for toothbrush disinfection. Sixty volunteers were divided into five experimental groups and one control group (n = 10). Participants brushed their teeth using toothbrushes with standard bristles, and they disinfected the toothbrushes according to instructed methods. Bacterial contamination of the toothbrushes was compared between the experimental groups and the control group. Data were analyzed by Kruskal-Wallis and Duncan's multiple range tests, with 95% confidence intervals for multiple comparisons. Bacterial contamination of toothbrushes from individuals in the experimental groups differed from those in the control group (p < 0.05). The most effective method for elimination of all tested bacterial species was 50% white vinegar, followed in order by 2% NaOCl, mouthrinse containing essential oils and alcohol, 0.12% chlorhexidine gluconate, dishwasher use, and tap water (control). The results of this study show that the most effective method for disinfecting toothbrushes was submersion in 50% white vinegar, which is cost-effective, easy to access, and appropriate for household use. PMID:26676193

  14. New Technologies to Improve Root Canal Disinfection.

    PubMed

    Plotino, Gianluca; Cortese, Teresa; Grande, Nicola M; Leonardi, Denise P; Di Giorgio, Gianni; Testarelli, Luca; Gambarini, Gianluca

    2016-01-01

    Effective irrigant delivery and agitation are prerequisites to promote root canal disinfection and debris removal and improve successful endodontic treatment. This paper presents an overview of the currently available technologies to improve the cleaning of the endodontic space and their debridement efficacy. A PubMed electronic search was conducted with appropriate key words to identify the relevant literature on this topic. After retrieving the full-text articles, all the articles were reviewed and the most appropriate were included in this review. Several different systems of mechanical activation of irrigants to improve endodontic disinfection were analysed: manual agitation with gutta-percha cones, endodontic instruments or special brushes, vibrating systems activated by low-speed hand-pieces or by sonic or subsonic energy, use of ultrasonic or laser energy to mechanically activate the irrigants and apical negative pressure irrigation systems. Furthermore, this review aims to describe systems designed to improve the intracanal bacterial decontamination by a specific chemical action, such as ozone, direct laser action or light-activated disinfection. The ultrasonic activation of root canal irrigants and of sodium hypochlorite in particular still remains the gold standard to which all other systems of mechanical agitation analyzed in this article were compared. From this overview, it is evident that the use of different irrigation systems can provide several advantages in the clinical endodontic outcome and that integration of new technologies, coupled with enhanced techniques and materials, may help everyday clinical practice. PMID:27007337

  15. [Principles of antisepsis, disinfection and sterilization].

    PubMed

    Hernández-Navarrete, María-Jesús; Celorrio-Pascual, José-Miguel; Lapresta Moros, Carlos; Solano Bernad, Victor-Manuel

    2014-12-01

    This article aims to provide a brief review of the main concepts on which the prevention and control of infection are based. Antisepsis comprises a set of techniques aimed at the total sterilization, or at most, disinfection, removing germs that contaminate an environment. Both procedures must be preceded by an environmental cleanup in the location in which they intend to be applied. The disinfection is carried out using biocides or germicides. Antimicrobial chemicals, that have mechanisms of action and resistances very similar to antibiotics, are generating concern due to the possibility of crossing genetic information that aggravates the problem of bacterial resistance. Most biocides can act as antiseptics, and applied to skin tissue, or disinfectants on inanimate materials. The spectrum of action of germicides depends on the product itself and external controllable factors: temperature, concentration, exposure time, etc. Sterilization techniques are primarily physical, by exposing the material to steam, or sterilizing gas, using autoclaves. Major advances are the use of low temperatures with shorter exposure times, in parallel with technological advances in instrumentation in order to avoid high temperatures and high use rotations due to workload. PMID:25023372

  16. Efficiency of water disinfectants against Legionella pneumophila and Acanthamoeba.

    PubMed

    Dupuy, Mathieu; Mazoua, Stéphane; Berne, Florence; Bodet, Charles; Garrec, Nathalie; Herbelin, Pascaline; Ménard-Szczebara, Florence; Oberti, Sandrine; Rodier, Marie-Hélène; Soreau, Sylvie; Wallet, France; Héchard, Yann

    2011-01-01

    Free-living amoebae might be pathogenic by themselves and be a reservoir for bacterial pathogens, such as Legionella pneumophila. Not only could amoebae protect intra-cellular Legionella but Legionella grown within amoebae could undergo physiological modifications and become more resistant and more virulent. Therefore, it is important to study the efficiency of treatments on amoebae and Legionella grown within these amoebae to improve their application and to limit their impact on the environment. With this aim, we compared various water disinfectants against trophozoites of three Acanthamoeba strains and L. pneumophila alone or in co-culture. Three oxidizing disinfectants (chlorine, monochloramine, and chlorine dioxide) were assessed. All the samples were treated with disinfectants for 1 h and the disinfectant concentration was followed to calculate disinfectant exposure (Ct). We noticed that there were significant differences of susceptibility among the Acanthamoeba strains. However no difference was observed between infected and non-infected amoebae. Also, the comparison between the three disinfectants indicates that monochloramine was efficient at the same level towards free or co-cultured L. pneumophila while chlorine and chlorine dioxide were less efficient on co-cultured L. pneumophila. It suggests that these disinfectants should have different modes of action. Finally, our results provide for the first time disinfectant exposure values for Acanthamoeba treatments that might be used as references for disinfection of water systems. PMID:21093012

  17. Resistance to chemical disinfection under conditions of microgravity

    NASA Astrophysics Data System (ADS)

    Marchin, George L.

    1998-01-01

    In unit gravity, bacteria and disinfecting resin beads co-sediment to the septum in a fluid processing apparatus (FPA) resulting in effective chemical disinfection. In microgravity bacteria in suspension have access to a larger volume of the FPA because of a lack of sedimentation. Further, when disinfecting resin beads are added to the FPA they also remain in suspension reducing their effective concentration. Typically, therefore, disinfection experiments in microgravity return larger numbers of viable bacteria than ground-based controls. Preliminary experiments aboard the MIR Space Station with Pseudomonas aeruginosa additionally suggest that the longer bacteria are retained in microgravity the more resistant they become to chemical disinfection. This phenomenon is probably due to additional time to develop resistant biofilms on the interior of the FPA. To partially solve these problems we have developed additional disinfecting materials to use in conjunction with polyiodide containing resin beads. One of these materials carbon beads coated with 3-trimethoxy silylpropyl dimethyloctadecyl ammonium chloride (Dow-Corning 5700®), acts synergistically with polyiodide resin disinfectants. Carbon beads so treated are still able to remove aqueous iodine from the water stream while providing an additional level of chemical disinfection. This additional capability prevents contamination of the carbon beads with heterotrophic bacteria and insures that bacteria surviving iodine disinfection are efficiently devitalized.

  18. Efficacy comparisons of disinfectants used by the commercial poultry industry.

    PubMed

    Ruano, M; El-Attrache, J; Villegas, P

    2001-01-01

    Several commercially available disinfectants used by the poultry industry were evaluated for their effectiveness against selected bacteria and viruses. When tested in the absence of organic matter, most disinfectant products were effective at the manufacturer's recommended level within 10 min of contact time. However, when organic matter was present, longer contact times and/or higher disinfectant dosages were needed to maintain effectiveness. Pseudomona aeruginosa and infectious laryngotracheitis virus were very resistant organisms in the presence of organic matter. Evaluation of disinfectant efficacy against several microbials in the absence or presence of organic matter was highly practical, flexible, and reproducible. PMID:11785901

  19. Hydrogen Peroxide as an Effective Disinfectant for Pasteurella multocida

    PubMed Central

    Jung, In-Soo; Kim, Hyun-Jung; Jung, Won-Yong

    2014-01-01

    Pasteurella multocida (P. multocida) infections vary widely, from local infections resulting from animal bites and scratches to general infections. As of yet, no vaccine against P. multocida has been developed, and the most effective way to prevent pathogenic transmission is to clean the host environment using disinfectants. In this study, we identified which disinfectants most effectively inhibited environmental isolates of P. multocida. Three readily available disinfectants were compared: 3% hydrogen peroxide (HP), 70% isopropyl alcohol, and synthetic phenol. In suspension tests and zone inhibition tests, 3% HP was the most promising disinfectant against P. multocida. PMID:24954350

  20. Effectiveness of various chemical disinfectants versus cleaning combined with heat disinfection on Pseudomonas biofilm in hemodialysis machines.

    PubMed

    Holmes, C J; Degremont, A; Kubey, W; Straka, P; Man, N K

    2004-01-01

    The development of bacterial biofilms in the hydraulic circuit of hemodialysis machines is routinely prevented by frequent use of a variety of chemical and heat disinfection strategies. This study compared the effectiveness of several chemical disinfectants, commonly used either alone or in combination with a treatment regimen that involved cleaning plus heat disinfection using an in vitro Pseudomonas biofilm model. Effectiveness of these procedures was evaluated using total and viable biomass quantitation and polysaccharide and endotoxin determination. The chemical disinfection procedures were only partially successful in removing all biofilm components. Heat disinfection alone killed viable biofilm bacteria, but did not remove all the biomass components, including endotoxin. The combination of cleaning with citric acid followed by heat disinfection was the most effective in eliminating all biofilm components from the hydraulic circuit of the in vitro model. PMID:15359105

  1. Digital imaging for the education of proper surgical hand disinfection.

    PubMed

    Haidegger, Tamás; Nagy, Melinda; Lehotsky, Akos; Szilágyi, László

    2011-01-01

    Nosocomial infections are the undesirable result of a treatment in a hospital, or a health care service unit, not related to the patient's original condition. Despite the evolution of medicine, fundamental problems with hand hygiene remain existent, leading to the spread of nosocomial infections. Our group has been working on a generic solution to provide a method and apparatus to teach and verify proper hand disinfection. The general idea is to mark the skin surfaces that were sufficiently treated with alcoholic hand rub. Digital image processing is employed to determine the location of these areas and overlay it on the segmented hand, visualizing the results in an intuitive form. A non-disruptive ultraviolet marker is mixed to a commercially available hand rub, therefore leaving the original hand washing workflow intact. Digital images are taken in an enclosed device we developed for this purpose. First, robust hand contour segmentation is performed, then a histogram-based formulation of the fuzzy c-means algorithm is employed for the classification of clean versus dirty regions, minimizing the processing time of the images. The method and device have been tested in 3 hospitals in Hungary, Romania and Singapore, on surgeons, residents, medical students and nurses. A health care professional verified the results of the segmentation, since no gold standard is available for the recorded human cases. We were able to identify the hand boundaries correctly in 99.2% of the cases. The device can give objective feedback to medical students and staff to develop and maintain proper hand disinfection practice. PMID:22003751

  2. A Modern Approach to Disinfection, as Old as the Evolution of Vertebrates

    PubMed Central

    Migliarina, Franco; Ferro, Sergio

    2014-01-01

    The immune system of vertebrates “naturally” produces hypochlorous acid (HOCl) to fight against bacteria and pathogens. A patented electrochemical technology mirrors the above defense system, allowing the synthesis of HOCl solutions through the electrolysis of water enriched in salts, at the level of a few grams per liter. The system allows for the careful control of the pH of produced solutions, with consequent optimization of their activity. Once the HOCl is introduced into the water system; it is able to remove the biofilm from pipe network; significantly decreasing the level of Legionella colonization; within 8–10 weeks from the beginning of the disinfection approach. The technology has been applied in a variety of healthcare facilities, both in Italy and in neighboring European countries. In the present paper, two successful case studies are briefly presented: Data were obtained from experiences in two different healthcare facilities, one in Italy and the other in Germany. Destruction of biofilm was indirectly testified by an increase of total organic carbon content of water; as a consequence, and because of the dosing of the disinfecting agent, some μg/L of total halomethanes were also formed. However, both compositional features were only observed during the initial stages of the disinfection treatment. PMID:27429291

  3. Effect of disinfection of custom tray materials on adhesive properties of several impression material systems.

    PubMed

    Thompson, G A; Vermilyea, S G; Agar, J R

    1994-12-01

    The effects of impression tray disinfection procedures on the bond strength of impression-material adhesives to two types of resin trays were evaluated with a tensile test. Autopolymerizing acrylic resin and a visible light-curing resin were formed into one-half inch cubes. A screw eye was attached to each cube before polymerization. Perforated trays were fabricated with stops to maintain an even one-eighth inch of impression material over the resin block. Hooks on the opposite side permitted attachment of the metal plate to a mechanical testing machine. Before adhesive was applied, one third of the resin specimens were immersed in a 1:213 iodophor solution; one third in a 10% sodium hypochlorite solution, and one third were kept in the "as fabricated" condition. Polysulfide, polyether, and polyvinyl siloxane impression material-adhesive systems were evaluated. The resin-impression material-metal plate couples were attached to a mechanical testing machine and tensile forces were applied at a separation rate of 5 inches per minute. Mean values for adhesive strength ranged from 3.49 kg/cm2 for the autopolymerizing acrylic resin/iodophor/polyether combination to 10.55 kg/cm2 for the autopolymerizing acrylic resin/untreated/polyvinyl siloxane combination. Differences were detected among materials and disinfecting procedure. Clinically, disinfection of resin trays may adversely affect retention of the impression material to the tray. PMID:7853264

  4. An evaluation of drinking water samples treated with alternative disinfectants

    SciTech Connect

    Patterson, K.S.; Lykins, B.W. Jr.; Garner, L.M.

    1995-10-01

    Due to concern over potential human health risks associated with the use of chlorine (Cl{sub 2}) for disinfection of drinking water, many utilities are considering alternative disinfectants. An evaluation is thus needed of the potential risks associated with the use of alternative disinfectants relative to those posed by Cl{sub 2}. At a pilot-scale drinking water plant in Jefferson Parish, LA., two studies were conducted in which clarified and sand filtered Mississippi River water was treated with either ozone (O{sub 3}), monochloramine (NH{sub 2}Cl), Cl{sub 2} or was not disinfected. Ozonated water was also post-disinfected with either NH{sub 2}Cl or Cl{sub 2}, to provide a disinfectant residual. For each treatment stream total organic carbon (TOC), total organic halide (TOX) and microbiological contaminants were determined. XAD resin concentrates were also prepared for mutagenicity testing in the Ames Salmonella assay. Water samples disinfected with O{sub 3} alone had low levels of mutagenic activity, the same as the non-disinfected water. The level of mutagenicity observed following chlorination was approximately twice that observed following treatment with NH{sub 2}Cl. Disinfection with O{sub 3} prior to treatment with either Cl{sub 2} or NH{sub 2}Cl resulted in a significantly lower level of mutagenicity than when either disinfectant was used alone. The concentrations of TOX present in the water samples showed a pattern similar to that of the mutagenicity data. The levels of TOC, by contrast, were similar for all the treatment streams. No significant baterial contamination was observed in water samples treated with either Cl{sub 2} or NH{sub 2}Cl alone or in combination with O{sub 3}, as determined by heterotrophic plate counts. However, O{sub 3} alone did not insure an acceptable level of disinfection at the end of the treatment stream.

  5. Evaluating Environmental Persistence and Disinfection of the Ebola Virus Makona Variant

    PubMed Central

    Cook, Bradley W. M.; Cutts, Todd A.; Nikiforuk, Aidan M.; Poliquin, Philip Guillaume; Court, Deborah A.; Strong, James E.; Theriault, Steven S.

    2015-01-01

    Background: The current disease outbreak caused by the Ebola virus Makona variant (EBOV/Mak) has led to unprecedented morbidity and lethality given its geographic reach and sustained transmission. Sodium hypochlorite and ethanol are well-accepted decontamination agents, however little published evidence supports the selection of appropriate concentrations and contact times. The present study addresses the environmental robustness of EBOV/Mak and evaluates the effectiveness of sodium hypochlorite and ethanol as disinfectants. Methods: EBOV/Mak was suspended in a simulated organic soil load and dried onto surfaces. Viability was measured at 1 hour, 24 hours, 72 hours, and 192 hours. For the evaluation of disinfectants, EBOV/Mak in a simulated organic soil was dried onto stainless steel carriers and disinfected with 0.01% (v/v), 0.1% (v/v), 0.5% (v/v) and 1% (v/v) sodium hypochlorite solutions or 67% (v/v) ethanol at contact times of 1, 5 or 10 minutes. Results: EBOV/Mak persisted longer on steel and plastic surfaces (192 hours) than cotton (<24 hours). Dilute sodium hypochlorite (0.01% and 0.1%) showed little antiviral action, whereas 0.5% and 1% sodium hypochlorite solutions demonstrated recoverable virus at one minute but sterilized surfaces in five minutes. Disinfection with 67% ethanol did not fully clear infectious virions from 3/9 carriers at 1 minute but sterilized all carriers at 5 and 10 minutes. Conclusions: Sodium hypochlorite and ethanol effectively decontaminate EBOV/Mak suspended in a simulated organic load; however, selection of concentration and contact time proves critical. PMID:25875372

  6. Comparing irradiation parameters on disinfecting enterrecoccus faecalis in root canal disinfection

    NASA Astrophysics Data System (ADS)

    Sarp, Ayşe. S.; Gülsoy, Murat

    2016-02-01

    Although conventional method carries all the debris, studies on persisting infections in root canals show bacteria and their toxins spread from the root canal and contaminate the apical region. Thus developes apical periodontitis or symptoms, and loss of tooth. Even if the treatment has adequate success, anatomy of root canal system can be very complexwith accessory canals. The disinfecting effect of laser radiation has only recently been used in dentistry. Laser irradiation has a bactericidal effect. Each wavelength has its own advantages and limitations according to their different absorption characteristics, depending on their 'absorption coefficient'. The sterilizing efficiency of two types of wavelengths, a new fiber laser 1940- nm Thulium fiber Laser and an 2940 nm Er:YAG Laser were compared in this study. Irradiation with a power of 0.50 W with 1940- nm Thulium fiber Laser disinfected 95,15% of bacteria, however irradiation with same laser power with Er:YAG Laser caused a reduction of 96,48 %. But there was no significant difference in the disinfection effect of two different laser groups ( p < 0.05, Mann- U-Whitney Test). In addition to this, Er :YAG Laser caused three times more reduction from its own positive control group where 1940- nm Thulium fiber Laser caused 2,5 times effective disinfection.

  7. 9 CFR 71.11 - Cresylic disinfectant as permitted disinfectant; specifications.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... disinfectant for use under the provisions of § 71.10(b)(3): (a) The product shall remain a uniform liquid when... than the equivalent of 0.5 percent of sodium hydroxide, and not less than 21 percent of soap exclusive... glyceride, fat acid, or resin acid may be used in preparing the soap, but not all are suitable nor are...

  8. 9 CFR 71.11 - Cresylic disinfectant as permitted disinfectant; specifications.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... disinfectant for use under the provisions of § 71.10(b)(3): (a) The product shall remain a uniform liquid when... than the equivalent of 0.5 percent of sodium hydroxide, and not less than 21 percent of soap exclusive... glyceride, fat acid, or resin acid may be used in preparing the soap, but not all are suitable nor are...

  9. 9 CFR 71.11 - Cresylic disinfectant as permitted disinfectant; specifications.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... disinfectant for use under the provisions of § 71.10(b)(3): (a) The product shall remain a uniform liquid when... than the equivalent of 0.5 percent of sodium hydroxide, and not less than 21 percent of soap exclusive... glyceride, fat acid, or resin acid may be used in preparing the soap, but not all are suitable nor are...

  10. TRIBROMOPYRROLE, BROMINATED ACIDS, AND OTHER DISINFECTION BYPRODUCTS PRODUCED BY DISINFECTION OF DRINKING WATER RICH IN BROMIDE

    EPA Science Inventory

    Using gas chromatography/mass spectrometry (GC/MS), we investigated the formation of disinfection byproducts (DBPs) from high bromide waters (2 mg/L) treated with chlorine or chlorine dioxide used in combination with chlorine and chloramines. This study represents the first comp...

  11. Drinking water and health: Disinfectants and disinfectant by-products. Volume 7

    SciTech Connect

    Not Available

    1987-01-01

    Studies of the toxicity of the by-products of disinfectants have focused on the trihalomethanes (THMs), which are formed during chlorination and for which considerable data on carcinogenicity have been developed. The level of total THMs in finished drinking water, currently regulated at 100 micrograms/L, should be reduced. Noting that chloroform is the principal THM produced by chlorination, the subcommittee found this level to be unsupportable on the basis of the risk values for chloroform developed in this review. Other, non-volatile by-products of chlorination may be important in contributing mutagenic properties to drinking water, especially when the natural water being treated contains high levels of organic matter. Short-term animal skin tests, although not conclusive, provide indications that organic concentrates from chlorinated water are tumorigenic under some experimental conditions. Unfortunately, many by-products of chlorination and other disinfection practices have not been identified. Consequently, the risks of ingesting cannot be quantified at present, but are potentially high enough to warrant continued efforts to analyze them. The use of alternative methods of drinking water disinfection is increasing, largely due to health and regulatory concerns about trihalomethanes. Thus, the nature and toxicity of the by-products of some other widely used water treatments (chloramination, ozonation, and chlorine dioxide) are also evaluated in the report to the extent allowed by available data. The subcommittee calculated quantitative risk assessment for disinfectants or their by-products when there was sufficient data.

  12. MUTAGENICITY AND DISINFECTION BY-PRODUCTS IN SURFACE DRINKING WATER DISINFECTED WITH PERACETIC ACID

    EPA Science Inventory

    The aims of this research were to study the influence of peracetic acid (PAA) on the formation of mutagens in surface waters used for human consumption and to assess its potential application for the disinfection of drinking water. The results obtained using PAA were compared to ...

  13. Efficacy of chlorine disinfection of soft contact lenses.

    PubMed

    Ferreira, J T; Kriel, F; van der Merwe, D; Pheiffer, G

    1991-09-01

    We evaluated the chlorine system SOFTAB (Alcon) for the disinfection of soft contact lenses. The results indicate that a 1000-fold reduction in microorganisms was achieved within 6 h. Even with the slight interference of residual cleaner and the more significant interference of organic matter disinfection was still achieved. PMID:1745498

  14. 9 CFR 51.31 - Disinfecting premises, conveyances, and materials.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.31 Disinfecting... brucellosis, must be properly cleaned and disinfected in accordance with recommendations of the APHIS or State... the Veterinarian in Charge determines that an extension will not adversely affect the...

  15. 9 CFR 51.31 - Disinfecting premises, conveyances, and materials.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.31 Disinfecting... brucellosis, must be properly cleaned and disinfected in accordance with recommendations of the APHIS or State... the Veterinarian in Charge determines that an extension will not adversely affect the...

  16. Zero-G Condensing Heat Exchanger with Integral Disinfection

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A. (Inventor)

    2012-01-01

    The system that operates in a zero gravity environment and has an integral ozone generating capability is disclosed. The system contributes to the control of metabolic water vapors in the air, and also provided disinfection of any resulting condensate within the system, as well as disinfection of the air stream that flows throughout the disclosed system.

  17. PERFORMANCE OF OZONE AS A DISINFECTANT FOR COMBINED SEWER OVERFLOW

    EPA Science Inventory

    Disinfection of combined sewer overflow (CSO) minimizes the amount of disease-causing microorganisms (pathogens) released into receiving waters. Currently, the primary disinfecting agent used in the US for wastewater treatment is chlorine (Cl2); however, Cl2 produces problems in ...

  18. The Next Generation of Drinking Water Disinfection By-Products

    EPA Science Inventory

    The disinfection of drinking water has been rightly hailed as a public health triumph of the 20th century. Millions of people worldwide receive quality drinking water every day from their public water systems. However, chemical disinfection has also produced an unintended healt...

  19. HIGH-RATE DISINFECTION TECHNIQUES FOR COMBIND SEWER OVERFLOW

    EPA Science Inventory

    This paper presents high-rate disinfection technologies for combined sewer overflow (CSO). The high-rate disinfection technologies of interest are: chlorination/dechlorination, ultraviolet light irradiation (UV), chlorine dioxide (ClO2 ), ozone (O3), peracetic acid (CH3COOOH )...

  20. Design and bidding of UV disinfection equipment -- Case study

    SciTech Connect

    Akyurek, M.

    1998-07-01

    Ultraviolet (UV) disinfection systems are being widely considered for application to treated wastewaters, in lieu of conventional chlorination facilities. The number of UV systems operating in the US was approximately 50 in 1984. In 1990 there were over 500 systems, a ten-fold increase. The use of UV disinfection has increased since 1990, and will likely to increase in the future. It is anticipated that as many chlorine disinfection facilities reach their useful life, most of them will be replaced with UV disinfection systems. Several manufacturers offer different UV disinfection equipment. Each offers something different for the designer. There are also different approaches used in estimating the number of lamps needed for the disinfection system. The lack of standardization in determination of the number of lamps for a UV system poses problems for the designer. Such was the case during the design of the disinfection system for the Watertown, SD Wastewater Treatment Plant (WWRP). The purpose of this paper is to present a case study for the design and bidding of UV disinfection equipment.

  1. [Scanning electron microscope study of chemically disinfected endodontic files].

    PubMed

    Navarro, G; Mateos, M; Navarro, J L; Canalda, C

    1991-01-01

    Forty stainless steel endodontic files were observed at scanning electron microscopy after being subjected to ten disinfection cycles of 10 minutes each one, immersed in different chemical disinfectants. Corrosion was not observed on the surface of the files in circumstances that this study was made. PMID:1659857

  2. Drowning in Disinfection Byproducts? Swimming Pool Water Quality

    EPA Science Inventory

    Disinfection is mandatory for swimming pools, because transmission of disease by bacteria, virus and protozoa is the most significant health issue. However another issue arises, and care should be taken to minimize the risks from disinfection by-products (DBPs). Public pools are ...

  3. IDENTIFICATION OF DISINFECTION BY-PRODUCTS IN SWIMMING POOL WATER

    EPA Science Inventory

    In order to kill harmful pathogens, swimming pool water is treated with a disinfectant, such as chlorine or ozone. One of the most commonly used disinfectants is stabilized chlorine (typically trichloro-S-triazinetrione). Trichloro-S-triazinetrione reacts in water to form one m...

  4. Products identified at an alternative disinfection pilot plant

    SciTech Connect

    Lykins, B.W. Jr.; Koffskey, W.

    1986-11-01

    Many drinking water utilities have recently changed or are seriously considering changing their disinfection practice from chlorine to some alternative treatment process. However, most of these utilities are changing their disinfectants without evaluating chemical impacts. Therefore, a research cooperative agreement was developed with Jefferson Parish, LA, to evaluate four parallel streams treated with four different disinfectants (chlorine, monochloramine, chlorine dioxide, and ozone.) These streams, along with a fifth parallel stream, which was not treated with a disinfectant (control), were passed through both sand and granular activated carbon (GAC). Ozonation reduced the total organic carbon (TOC) and total organic halide (TOX) concentration by 0.3 mg/L and 10 micrograms/L, respectively. The average concentration of TOC for the other disinfectants was comparable to that associated with the nondisinfected stream (3.3 mg/L). The average instantaneous TOX concentration for chlorine dioxide, chloramine, and chlorine disinfection after 30 min contact time increased by 60, 92, and 238 micrograms/L, respectively, from a nondisinfected concentration of 25 micrograms/L. The volatile organics most affected by disinfection (chlorination) were the trihalomethanes. No significant change in concentration was noted after disinfection for the other volatile organics evaluated, such as 1,2-dichlorethane, dichloromethane, trichloroethylene, 1,1,2-trichloroethane, and carbon tetrachloride. Ozonation produced an average concentration reduction of 11 to 84% for most of the nonvolatiles evaluated. Conversely, a concentration increase of 43 to 100% was noted, after chlorination, for some of the nonvolatile organics.

  5. Microbial contamination in sprouts: how effective is seed disinfection treatment?

    PubMed

    Ding, Hongliu; Fu, Tong-Jen; Smith, Michelle A

    2013-04-01

    Microbial contamination of sprouts by Salmonella and Escherichia coli O157 : H7 has been a common cause of foodborne diseases and a continuing challenge to the sprout industry. Seed disinfection treatment has been recommended as a major intervention step in a multihurdle approach to reduce the risk of illness associated with contaminated sprouts. U.S. Food and Drug Administration cited 20000 ppm calcium hypochlorite as an example treatment in its recommendation for seed treatment and this treatment has been considered the reference standard for seed disinfection treatment for over a decade. However, promising new disinfection treatments have emerged in recent years. In this study, we summarized published data and compared the efficacies of different disinfection methods in the reduction of microbial contamination on seeds. Our findings suggest that while biological interventions such as competitive exclusion and certain chemical treatments appear to be similar to 20000 ppm calcium hypochlorite for seed disinfection, physical methods especially high pressure may be more effective than the reference standard regardless of the type of bacteria or seed. The combination of 2 or more treatments, sequentially or simultaneously, may further improve disinfection results. Since treatments with high levels of chemical disinfectants, especially 20000 ppm calcium hypochlorite, can pose environmental and worker safety risks, alternative intervention approaches should be considered. Additional studies to confirm the greater efficacy of certain physical and combined seed disinfection treatments and to identify other effective management strategies are needed to further improve sprout safety. PMID:23464679

  6. CONCERNS WITH USING CHLORINE DIOXIDE DISINFECTION IN THE UNITED STATES

    EPA Science Inventory

    There is a renewed interest in disinfection with chlorine dioxide in the United States because of upcoming Federal regulations on disinfection by-products. ench studies and field applications of chlorine dioxide have shown that it is an effective biocide that does not produce hal...

  7. ULTRAVIOLET LIGHT DISINFECTION OF COMBINED SEWER OVERFLOW (NEW ORLEANS)

    EPA Science Inventory

    The objective of this state-of-the-art review is to examine the performance and effectiveness of ultraviolet (UV) light disinfection for combined sewer overflow (CSO) applications. Topics presented include the use of UV light as a disinfecting agent, its practical applications, d...

  8. The Next Generation of Disinfection By-Products

    EPA Science Inventory

    The disinfection of drinking water has been rightly hailed as a public health triumph of the 20th century. Millions of people worldwide receive quality drinking water every day from their public water systems. However, chemical disinfection has also produced an unintended health ...

  9. Disinfection By-Products: Formation and Occurrence in Drinking Water

    EPA Science Inventory

    The disinfection of drinking water has been rightly hailed as a public health triumph of the twentieth century. Millions of people worldwide receive quality drinking water every day from their public water systems. However, chemical disinfection has also produced an unintended he...

  10. Genotoxicity of Disinfection By-products: Comparison to Carcinogenicity

    EPA Science Inventory

    Disinfection by-products (DBPs) can be formed when water is disinfected by various agents such as chlorine, ozone, or chloramines. Among the >600 DBPs identified in drinking water, 11 are regulated by the U.S. Environmental Protection Agency, and another ~70 DBPs that occur at s...

  11. New technologies and trends in sterilization and disinfection.

    PubMed

    Schneider, Philip M

    2013-05-01

    Continued improvements in low-temperature sterilization systems have resulted in reduced processing times and expanded capabilities for instrument reprocessing. As the relationship of environmental surface contamination and health care-associated infections has become more defined, area disinfection systems and antimicrobial surface technologies have emerged as new strategies for disinfection of surfaces. PMID:23622756

  12. ALTERNATIVE OXIDANT AND DISINFECTANT TREATMENT STRATEGIES FOR CONTROLLING TRIHALOMETHANE FORMATION

    EPA Science Inventory

    To comply with the maximum contaminant level (MCL) for total trihalomethanes (TTHM), many utilities have modified their pre-oxidation and disinfection practices by switching to alternative oxidants and disinfectants in place of free chlorine. To evaluate the impact of these chang...

  13. The alternative methods for disinfection of E. coli

    NASA Astrophysics Data System (ADS)

    Yetim, Tuba; Görmez, Arzu; Gürkök, Sümeyra

    2016-04-01

    Recently, advanced oxidation processes have gained significant interest for bacterial inactivation. In the present study, the efficacy of sonolysis, photocatalysis and sonophotocatalysis was evaluated for disinfection of Escherichia coli O157:H7 strain. Sonophotocatalysis proved to be the most effective disinfection methods by generating greater amount of •OHradical.

  14. 7 CFR 301.89-12 - Cleaning, disinfection, and disposal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Cleaning, disinfection, and disposal. 301.89-12 Section 301.89-12 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Karnal Bunt § 301.89-12 Cleaning, disinfection, and disposal....

  15. Disinfection of water in recirculating aquaculture systems with peracetic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peracetic acid (PAA) has become a favoured alternative to chlorination in the disinfection of municipal waste water in recent years. It is also commonly used in the food industry as a disinfectant. Based on PAA concentration, the disulfide linkage in enzymes and proteins of microorganisms can be bro...

  16. Mutagenic activity of disinfection by-products.

    PubMed Central

    Cognet, L; Courtois, Y; Mallevialle, J

    1986-01-01

    Data on raw water quality, disinfection treatment practices, and the resulting mutagenic properties of the treated water were compiled from pilot- and full-scale treatment experiments to evaluate that parameter which might produce variability in the results of a mutagenic study. Analysis of the data and comparison of treatment practices indicated that the measured mutagenic activity is strongly related to the characteristics of the organic matter in the raw water, the methodology used to sample and detect mutagens, the scale of the study both in terms of treatment flow and period of study, and the point at which and the conditions under which oxidants are added during treatment. Conclusions regarding disinfection systems in full-scale water treatment plants include the following: When raw water is pretreated and high concentrations of organics are present in the raw water, both ozonation and chlorination increased mutagenic activity. However, no significant difference in mutagenicity was found between the two oxidants. Both in the case of a nitrified groundwater and a clarified surface water, the mutagenic activity of the water after ozonation was related to its mutagenic activity before ozonation. With ozonation, mutagenic activity decreased after granular activated carbon (GAC) filtration. Thus, when GAC filtration follows ozone disinfection, early addition of oxidants may not be deleterious to the finished water quality. When chlorine or chlorine dioxide is added after GAC filtration, chlorine dioxide was found to produce a less mutagenic water than chlorine. Although these conclusions suggest means of controlling mutagenic activity during treatment, it must be stressed that the measurement of mutagenicity is a presumptive index of contamination level. PMID:3816721

  17. Exposure to common quaternary ammonium disinfectants decreases fertility in mice

    PubMed Central

    Melin, Vanessa E.; Potineni, Haritha; Hunt, Patricia; Griswold, Jodi; Siems, Bill; Werre, Stephen R.; Hrubec, Terry C.

    2014-01-01

    Quaternary ammonium compounds (QACs) are antimicrobial disinfectants commonly used in commercial and household settings. Extensive use of QACs results in ubiquitous human exposure, yet reproductive toxicity has not been evaluated. Decreased reproductive performance in laboratory mice coincided with the introduction of a disinfectant containing both alkyl dimethyl benzyl ammonium chloride (ADBAC) and didecyl dimethyl ammonium chloride (DDAC). QACs were detected in caging material over a period of several months following cessation of disinfectant use. Breeding pairs exposed for six months to a QAC disinfectant exhibited decreases in fertility and fecundity: increased time to first litter, longer pregnancy intervals, fewer pups per litter and fewer pregnancies. Significant morbidity in near term dams was also observed. In summary, exposure to a common QAC disinfectant mixture significantly impaired reproductive health in mice. This study illustrates the importance of assessing mixture toxicity of commonly used products whose components have only been evaluated individually. PMID:25483128

  18. UV disinfection pilot plant study at the Savannah River Site

    SciTech Connect

    Huffines, R.L.; Beavers, B.A.

    1993-01-01

    An ultraviolet light disinfection system pilot plant was operated at the Savannah River Site Central Shops sanitary wastewater treatment package plant July 14, 1992 through August 13, 1992. The purpose was to determine the effectiveness of ultraviolet light disinfection on the effluent from the small package-type wastewater treatment plants currently used on-site. This pilot plant consisted of a rack of UV lights suspended in a stainless steel channel through which a sidestream of effluent from the treatment plant clarifier was pumped. Fecal coliform analyses were performed on the influent to and effluent from the pilot unit to verify the disinfection process. UV disinfection was highly effective in reducing fecal coliform colonies within NPDES permit limitations even under process upset conditions. The average fecal coliform reduction exceeded 99.7% using ultraviolet light disinfection under normal operating conditions at the package treatment plants.

  19. UV disinfection pilot plant study at the Savannah River Site

    SciTech Connect

    Huffines, R.L.; Beavers, B.A.

    1993-05-01

    An ultraviolet light disinfection system pilot plant was operated at the Savannah River Site Central Shops sanitary wastewater treatment package plant July 14, 1992 through August 13, 1992. The purpose was to determine the effectiveness of ultraviolet light disinfection on the effluent from the small package-type wastewater treatment plants currently used on-site. This pilot plant consisted of a rack of UV lights suspended in a stainless steel channel through which a sidestream of effluent from the treatment plant clarifier was pumped. Fecal coliform analyses were performed on the influent to and effluent from the pilot unit to verify the disinfection process. UV disinfection was highly effective in reducing fecal coliform colonies within NPDES permit limitations even under process upset conditions. The average fecal coliform reduction exceeded 99.7% using ultraviolet light disinfection under normal operating conditions at the package treatment plants.

  20. Impact of disinfection on drinking water biofilm bacterial community.

    PubMed

    Mi, Zilong; Dai, Yu; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-11-01

    Disinfectants are commonly applied to control the growth of microorganisms in drinking water distribution systems. However, the effect of disinfection on drinking water microbial community remains poorly understood. The present study investigated the impacts of different disinfectants (chlorine and chloramine) and dosages on biofilm bacterial community in bench-scale pipe section reactors. Illumina MiSeq sequencing illustrated that disinfection strategy could affect both bacterial diversity and community structure of drinking water biofilm. Proteobacteria tended to predominate in chloraminated drinking water biofilms, while Firmicutes in chlorinated and unchlorinated biofilms. The major proteobacterial groups were influenced by both disinfectant type and dosage. In addition, chloramination had a more profound impact on bacterial community than chlorination. PMID:26574105

  1. Regenerable Iodine Water-Disinfection System

    NASA Technical Reports Server (NTRS)

    Sauer, Richard L.; Colombo, Gerald V.; Jolly, Clifford D.

    1994-01-01

    Iodinated resin bed for disinfecting water regenerated to extend its useful life. Water flows through regeneration bed of crystalline iodine during regeneration. At other times, flow diverted around regeneration bed. Although regeneration cycle was manually controlled in demonstration, readily automated to start and stop according to signals and stop according to signals from concentration sensors. Further benefit of regeneration is that regeneration bed provides highly concentrated biocide source (200 mg/L) when needed. Concentrated biocide used to superiodinate system after contamination from routine maintenance or unexpected introduction of large concentration of microbes.

  2. The role of surface disinfection in infection prevention

    PubMed Central

    Gebel, Jürgen; Exner, Martin; French, Gary; Chartier, Yves; Christiansen, Bärbel; Gemein, Stefanie; Goroncy-Bermes, Peter; Hartemann, Philippe; Heudorf, Ursel; Kramer, Axel; Maillard, Jean-Yves; Oltmanns, Peter; Rotter, Manfred; Sonntag, Hans-Günther

    2013-01-01

    Background: The Rudolf Schuelke Foundation addresses topics related to hygiene, infection prevention and public health. In this context a panel of scientists from various European countries discussed “The Role of Surface Disinfection in Infection Prevention”. The most important findings and conclusions of this meeting are summarised in the present consensus paper. Aim: Although the relevance of surface disinfection is increasingly being accepted, there are still a number of issues which remain controversial. In particular, the following topics were addressed: Transferral of microbes from surface to patients as a cause of infection, requirements for surface disinfectants, biocidal resistance and toxicity, future challenges. Methods and findings: After discussion and review of current scientific literature the authors agreed that contaminated surfaces contribute to the transmission of pathogens and may thus pose an infection hazard. Targeted surface disinfection based on a risk profile is seen as an indispensable constituent in a multibarrier approach of universal infection control precautions. Resistance and cross-resistance depend on the disinfectant agent as well as on the microbial species. Prudent implementation of surface disinfection regimens tested to be effective can prevent or minimize adverse effects. Conclusions: Disinfection must be viewed as a holistic process. There is a need for defining standard principles for cleaning and disinfection, for ensuring compliance with these principles by measures such as written standard operating procedures, adequate training and suitable audit systems. Also, test procedures must be set up in order to demonstrate the efficacy of disinfectants including new application methods such as pre-soaked wipes for surface disinfection. PMID:23967396

  3. Inactivation of dairy bacteriophages by commercial sanitizers and disinfectants.

    PubMed

    Campagna, Céline; Villion, Manuela; Labrie, Simon J; Duchaine, Caroline; Moineau, Sylvain

    2014-02-01

    Many commercial sanitizers and disinfectants have been used over the years to control microbial contamination but their efficacy on phages is often unknown. Here, 23 commercial chemical products, including 21 food-grade sanitizers were tested against virulent dairy phages. These food-grade chemicals included oxidizing agents, halogenated agents, alcohols, quaternary ammonium compounds, anionic acids, iodine-based acids, and an amphoteric chemical. Phage P008 was first exposed to each sanitizer for 2 and 15min at room temperature and at two different concentrations, namely the lowest and highest no-rinse sanitizing concentrations. Organic matter (whey or milk) was also added to the testing solutions. At the end of the exposure period, the test solution was neutralized and the number of infectious phages was determined by plaque assays. The five most efficient sanitizers against phage P008 (<4 log of inactivation) were then tested against virulent lactococcal phages P008, CB13, AF6, P1532 of the 936 group, P001 (c2), Q54, and 1358 as well as Lactobacillus plantarum phage B1 and Streptococcus thermophilus phage 2972 using the same protocol. The oxidizing agents and the quaternary ammonium compounds were the most efficient against all phages although phages CB13 and P1532 were less sensitive to these chemicals than the other phages. This study may help in the selection of appropriate chemicals for controlling phage contamination in industrial factories and research laboratories. PMID:24321601

  4. Virucidal activity of alcohol-based hand rub disinfectants.

    PubMed

    Iwasawa, Atsuo; Niwano, Yoshimi; Kohno, Masahiro; Ayaki, Masahiko

    2012-03-01

    We investigated the virucidal activity of commercially available alcohol-based hand rub products against coxsackievirus A7, B5, feline calicivirus F9, and human adenovirus type 3, type 7, type 8 using susceptible cell lines, Vero cells, CRFK cells, and A549 cells. Fifteen tested hand rub products were ethanol (EtOH) for disinfection (Japanese Pharmacopoeia Grade), two EtOH-based products, one povidone iode-containing product, one alkyldiaminoethylglycine hydrochloride-containing product, six benzalkonium chloride (BAK)-containing products, and four chlorohexidine gluconate (CHG)-containing products. Some active ingredients (BAK, benzetonium chloride, and CHG) were diluted with EtOH to make 0.5% and 0.2% solutions. Virus inactivation rates were calculated after contact with each hand rub product for 10 or 60 seconds. Of the hand rub products tested, only the povidone iode-based product showed antiviral activity superior to that of EtOH against all the strains. EtOH solutions of active ingredients (0.2% and 0.5%) also showed decreased antiviral activity. In conclusion, antiviral activity of all the commercially available alcohol-based hand rub products except that containing povidone idode was dependent on their active ingredients. The povidone idode-containing hand rub product kept its effectiveness even after the dilution with EtOH. Although alcohol-based hand rub products are convenient and suitable for the control of some microbes, they are not generally recommended for the control of viral infections. PMID:22451431

  5. Efficacy of oxidizing disinfectants at inactivating murine norovirus on ready-to-eat foods.

    PubMed

    Girard, Maryline; Mattison, Kirsten; Fliss, Ismail; Jean, Julie

    2016-02-16

    Noroviruses are the leading cause of foodborne illness, and ready-to-eat foods are frequent vehicles of their transmission. Studies of the disinfection of fruits and vegetables are becoming numerous. It has been shown that strong oxidizing agents are more effective than other chemical disinfectants for inactivating enteric viruses. The aim of this study was to evaluate the efficacy of oxidizing disinfectants (sodium hypochlorite, chloride dioxide and peracetic acid) at inactivating noroviruses on fruits and vegetables, using a norovirus surrogate, namely murine norovirus 3, which replicates in cell culture. Based on plaque assay, solutions of peracetic acid (85 ppm) and chlorine dioxide (20 ppm) reduced the infectivity of the virus in suspension by at least 3 log10 units after 1 min, while sodium hypochlorite at 50 ppm produced a 2-log reduction. On the surface of blueberries, strawberries and lettuce, chlorine dioxide was less effective than peracetic acid and sodium hypochlorite, which reduced viral titers by approximately 4 logs. A surprising increase in the efficacy of sodium hypochlorite on surfaces fouled with artificial feces was noted. PMID:26686597

  6. Comparative evaluation of tensile strength of Gutta-percha cones with a herbal disinfectant

    PubMed Central

    Mahali, Raghunandhan Raju; Dola, Binoy; Tanikonda, Rambabu; Peddireddi, Suresh

    2015-01-01

    Aim: To evaluate and compare the tensile strength values and influence of taper on the tensile strength of Gutta-percha (GP) cones after disinfection with sodium hypochlorite (SH) and Aloe vera gel (AV). Materials and Methods: Sixty GP cones of size 110, 2% taper, 60 GP cones F3 ProTaper, and 60 GP of size 30, 6% taper were obtained from sealed packs as three different groups. Experimental groups were disinfected with 5.25% SH and 90% AV gel except the control group. Tensile strengths of GP were measured using the universal testing machine. Results: The mean tensile strength values for Group IA, IIA and IIIA are 11.8 MPa, 8.69 MPa, and 9.24 MPa, respectively. Results were subjected to statistical analysis one-way analysis of variance test and Tukey post-hoc test. 5.25% SH solutions decreased the tensile strength of GP cones whereas with 90% AV gel it was not significantly altered. Conclusion: Ninety percent Aloe vera gel as a disinfectant does not alter the tensile strength of GP cones PMID:26752842

  7. Adsorption of MS2 on oxide nanoparticles affects chlorine disinfection and solar inactivation.

    PubMed

    Zhang, Wen; Zhang, Xuezhi

    2015-02-01

    Adsorption on colloidal particles is one of the environmental processes affecting fate, transport, viability or reproducibility of viruses. This work studied colloidal interactions (adsorption kinetics and isotherms) between different oxide nanoparticles (NPs) (i.e., TiO2, NiO, ZnO, SiO2, and Al2O3) and bacteriophage, MS2. The results shows that that all oxide NPs exhibited strong adsorption capacity for MS2, except SiO2 NPs, which is supported by the extended Derjaguin and Landau, Verwey and Overbeek (EDLVO) theory. Moreover, the implication of such colloidal interactions on water disinfection is manifested by the observations that the presence of TiO2 and ZnO NPs could enhance MS2 inactivation under solar irradiation, whereas NiO and SiO2 decreased MS2 inactivation. By contrast, all of these oxide NPs were found to mitigate chlorine disinfection against MS2 to different extent, and the shielding effect was probably caused by reduced free chlorine and free MS2 in the solution due to sorption onto NPs. Clearly, there is a pressing need to further understand colloidal interactions between engineered NPs and viruses in water to better improve the current water treatment processes and to develop novel nanomaterials for water disinfection. PMID:25437338

  8. Oxidation of diclofenac by aqueous chlorine dioxide: identification of major disinfection byproducts and toxicity evaluation.

    PubMed

    Wang, Yingling; Liu, Haijin; Liu, Guoguang; Xie, Youhai

    2014-03-01

    Diclofenac (DCF), a synthetic non-steroidal anti-inflammatory drug, is one of the most frequently detected pharmaceuticals in the aquatic environment. In this work, the mechanism and toxicity of DCF degradation by ClO2 under simulated water disinfection conditions were investigated. Experimental results indicate that rapid and significant oxidation of DCF occurred within the first few minutes; however, its mineralization process was longer than its degradation process. UPLC-MS and (1)H NMR spectroscopy were performed to identify major disinfection byproducts that were generated in three tentative degradation routes. The two main routes were based on initial decarboxylation of DCF on the aliphatic chain and hydroxylation of the phenylacetic acid moiety at the C-4 position. Subsequently, the formed aldehyde intermediates were the starting point for further multistep degradation involving decarboxylation, hydroxylation, and oxidation reactions of CN bond cleavage. The third route was based on transient preservation of chlorinated derivatives resulting from electrophilic attack by chlorine on the aromatic ring, which similarly underwent CN bond cleavage. Microtox bioassay was employed to evaluate the cytotoxicity of solutions treated by ClO2. The formation of more toxic mid-byproducts during the ClO2 disinfection process poses a potential risk to consumers. PMID:24388821

  9. Reducing the chlorine dioxide demand in final disinfection of drinking water treatment plants using activated carbon.

    PubMed

    Sorlini, Sabrina; Biasibetti, Michela; Collivignarelli, Maria Cristina; Crotti, Barbara Marianna

    2015-01-01

    Chlorine dioxide is one of the most widely employed chemicals in the disinfection process of a drinking water treatment plant (DWTP). The aim of this work was to evaluate the influence of the adsorption process with granular activated carbon (GAC) on the chlorine dioxide consumption in final oxidation/disinfection. A first series of tests was performed at the laboratory scale employing water samples collected at the outlet of the DWTP sand filter of Cremona (Italy). The adsorption process in batch conditions with seven different types of GAC was studied. A second series of tests was performed on water samples collected at the outlet of four GAC columns installed at the outlet of the DWTP sand filter. The results showed that the best chlorine dioxide demand (ClO2-D) reduction yields are equal to 60-80% and are achieved in the first 30 min after ClO2 addition, during the first 16 days of the column operation using a mineral, coal-based, mesoporous GAC. Therefore, this carbon removes organic compounds that are more rapidly reactive with ClO2. Moreover, a good correlation was found between the ClO2-D and UV absorbance at wavelength 254 nm using mineral carbons; therefore, the use of a mineral mesoporous GAC is an effective solution to control the high ClO2-D in the disinfection stage of a DWTP. PMID:25465650

  10. Quantitative evaluation of the effects of disinfectants against viruses in suspension experiments.

    PubMed

    Moldenhauer, D

    1984-12-01

    Time concentration relations in virus-disinfection by formaldehyde, benzalkonium-chloride, ethanol and isopropanol are evaluated. The exposure time needed to reduce the number of plaque-forming units (PFU) by 10(-3) (99.9%) at a given disinfectant concentration was determined. Influenzavirus, Coxsackie B viruses, Herpesvirus and Mumpsvirus were used in the experiments. Formaldehyde is effective at very low concentrations, provided that sufficient time is allowed for reaction, but has little use in short-term applications. Alcohols act very rapidly at the optimal concentration, but are almost completely ineffective if the reagent is only slightly diluted. Isopropanol does not neutralize entero-viruses to any considerable extent. The effect of the alcohols on viruses is greatly enhanced by the addition of alkali. An 80% (or higher) ethanol solution containing 0.01 n NaOH is very promising as a potent antiviral disinfectant for skin and surface decontamination. Even closely related virus types may differ greatly in their sensitivity to ethanol. The Herpesvirus hominis has a peculiarly high sensitivity to benzalconiumchloride, a sensitivity which is not shared by the Influenzavirus and enteroviruses. PMID:6099667

  11. Corrosion control and disinfection studies in spacecraft water systems. [considering Saturn 5 orbital workshop

    NASA Technical Reports Server (NTRS)

    Shea, T. G.

    1974-01-01

    Disinfection and corrosion control in the water systems of the Saturn 5 Orbital Workshop Program are considered. Within this framework, the problem areas of concern are classified into four general areas: disinfection; corrosion; membrane-associated problems of disinfectant uptake and diffusion; and taste and odor problems arising from membrane-disinfectant interaction.

  12. Certified Athletic Trainers' Knowledge of Methicillin-Resistant Staphylococcus aureus and Common Disinfectants

    PubMed Central

    Kahanov, Leamor; Gilmore, Elizabeth J.; Eberman, Lindsey E.; Roberts, Jeffrey; Semerjian, Tamar; Baldwin, Linda

    2011-01-01

    Context: Methicillin-resistant Staphylococcus aureus (MRSA) infections are increasingly common in athletic settings. The MRSA knowledge and infection-control practices of certified athletic trainers (ATs) and the cleanliness of the athletic training room are important factors in preventing MRSA infections. Objective: To assess knowledge of MRSA and the use of common disinfectants among ATs and to explore their infection-control practices. Design: Cross-sectional study. Setting: High school and collegiate athletic training rooms. Patients or Other Participants: A total of 163 ATs from National Collegiate Athletic Association Divisions I, II, and III and high schools, representing all 10 National Athletic Trainers' Association districts. Main Outcome Measure(s): Frequencies, analyses of variance, and χ2 tests were used to assess current practices and opinions and relationships between factors. Results: Methicillin-resistant Staphylococcus aureus was perceived as a national problem by 92% of respondents; 57% perceived MRSA as a problem in their practice setting. Most respondents had treated general infections (88%), staphylococcal infections (75%), and MRSA infections (57%). Male sex was associated with treating all 3 types of infections (χ2 test, P < .05). Noncurriculum education was associated with a lack of recognition of environmental issues as risk factors and with the use of isopropyl alcohol for disinfection (χ2 test, P < .05). For example, 10% of respondents did not recognize that contaminated whirlpools can be a source of MRSA infection. Respondents also incorrectly identified effective cleaning solutions. Thirty percent of respondents cleaned their hands frequently or sometimes before treating each athlete and 35% cleaned their hands sometimes, occasionally, or never after seeing each athlete. Conclusions: The majority of ATs were informed about MRSA and made correct disinfection choices. However, improvements are still needed, and not all ATs were using

  13. Evaluating the Efficiency of Lettuce Disinfection According to the Official Protocol in Iran

    PubMed Central

    Yarahmadi, M; Yunesian, M; Pourmand, MR; Shahsavani, A; Mubedi, I; Nomanpour, B; Naddafi, K

    2012-01-01

    Background The objective of this study was to evaluate the efficacy of Sanitization of Lettuce according to the protocols set forth by Iranian Ministry of Health and Medical Education for reducing populations of total coliform, fecal coliform, and helminth eggs present on lettuce. Methods: In the present study, we determined the load of total coliform, fecal coliform, and parasites of lettuce. The lettuce was sanitized by protocol of Iranian Ministry of Health and Medical Education. The protocol consists of 3 levels to disinfect the fruits and vegetables. The procedure was as follows: first washing stage. The leaves of leafy vegetables washed with tap water, second stage, separation of helminth eggs by 3 to 5 droplets of detergent per liter for 5 min; third stage, disinfection of vegetables by calcium hypochlorite solution (with 200 mg/l free chlorine) for 5 min; and finally the disinfected vegetables were washed with tap water. Results: The average initial levels of total coliform and fecal coliform in the samples were 3.36 log10 cfu/g and 2.31 log10 cfu/g, respectively. Helminth eggs were not detected in any of the samples tested. The efficiency of total coliform and fecal coliform removal were 78.1% (0.75 log10cfu/g) and 79.6% (0.67 log10cfu/g), respectively, after washing. This increased up to 94.8(1.44 log10cfu/g) and 98.5% (1.90 log10cfu/g) after the use of detergent. Chlorine disinfection rose these amounts up to 98.3% (2.18 log10cfu/g) and 100% (2.31 log10cfu/g), respectively. Conclusion: By applying the protocol large parts of microorganisms existing on lettuce have indeed been removed. PMID:23113153

  14. Virus Sensitivity Index of UV disinfection.

    PubMed

    Tang, Walter Z; Sillanpää, Mika

    2015-01-01

    A new concept of Virus Sensitivity Index (VSI) is defined as the ratio between the first-order inactivation rate constant of a virus, ki, and that of MS2-phage during UV disinfection, kr. MS2-phage is chosen as the reference virus because it is recommended as a virus indicator during UV reactor design and validation by the US Environmental Protection Agency. VSI has wide applications in research, design, and validation of UV disinfection systems. For example, it can be used to rank the UV disinfection sensitivity of viruses in reference to MS2-phage. There are four major steps in deriving the equation between Hi/Hr and 1/VSI. First, the first-order inactivation rate constants are determined by regression analysis between Log I and fluence required. Second, the inactivation rate constants of MS2-phage are statistically analysed at 3, 4, 5, and 6 Log I levels. Third, different VSI values are obtained from the ki of different viruses dividing by the kr of MS2-phage. Fourth, correlation between Hi/Hr and 1/VSI is analysed by using linear, quadratic, and cubic models. As expected from the theoretical analysis, a linear relationship adequately correlates Hi/Hr and 1/VSI without an intercept. VSI is used to quantitatively predict the UV fluence required for any virus at any log inactivation (Log I). Four equations were developed at 3, 4, 5, and 6 Log I. These equations have been validated using external data which are not used for the virus development. At Log I less than 3, the equation tends to under-predict the required fluence at both low Log I such as 1 and 2 Log I. At Log I greater than 3 Log I, the equation tends to over-predict the fluence required. The reasons for these may very likely be due to the shoulder at the beginning and the tailing at the end of the collimated beam test experiments. At 3 Log I, the error percentage is less than 6%. The VSI is also used to predict inactivation rate constants under two different UV disinfection

  15. A review of heterogeneous photocatalysis for water and surface disinfection.

    PubMed

    Byrne, John Anthony; Dunlop, Patrick Stuart Morris; Hamilton, Jeremy William John; Fernández-Ibáñez, Pilar; Polo-López, Inmaculada; Sharma, Preetam Kumar; Vennard, Ashlene Sarah Margaret

    2015-01-01

    Photo-excitation of certain semiconductors can lead to the production of reactive oxygen species that can inactivate microorganisms. The mechanisms involved are reviewed, along with two important applications. The first is the use of photocatalysis to enhance the solar disinfection of water. It is estimated that 750 million people do not have accessed to an improved source for drinking and many more rely on sources that are not safe. If one can utilize photocatalysis to enhance the solar disinfection of water and provide an inexpensive, simple method of water disinfection, then it could help reduce the risk of waterborne disease. The second application is the use of photocatalytic coatings to combat healthcare associated infections. Two challenges are considered, i.e., the use of photocatalytic coatings to give "self-disinfecting" surfaces to reduce the risk of transmission of infection via environmental surfaces, and the use of photocatalytic coatings for the decontamination and disinfection of medical devices. In the final section, the development of novel photocatalytic materials for use in disinfection applications is reviewed, taking account of materials, developed for other photocatalytic applications, but which may be transferable for disinfection purposes. PMID:25830789

  16. Microbiological methods for testing disinfectant efficiency on Pseudomonas biofilm.

    PubMed

    Wirtanen; Salo; Helander; Mattila-Sandholm

    2001-01-15

    Biofilms of the Gram-negative bacteria Pseudomonas aeruginosa and Pseudomonas fragi were grown on stainless steel surfaces (AISI 304, 2B) for 4 days in slime broth. These biofilms were treated with four commercial disinfectants. The disinfectants were alcohol-based, tenside-based, peroxide-based and chlorine-based products, covering most disinfectant types used in the food industry. The effects of the disinfectants on the bacterial cells were first investigated in suspension using the permeabilisation test, which is based on fluorescence assessment of hydrophobic 1-N-phenyl-naphtylamine (NPN). The surfaces covered with disinfectant-treated biofilms were investigated using conventional cultivation, impedimetry and epifluorescence microscopy in combination with image analysis of preparations stained with the DNA-stain acridine orange and with the metabolic indicator system CTC-DAPI. The results showed that the tenside-based and peroxide-based disinfectants permeabilised the cells in suspension. The overall biofilm results showed that of the agents tested, the peroxide-based and chlorine-based disinfectants acted most effectively on cells in biofilms. PMID:11084307

  17. Sterilization, high-level disinfection, and environmental cleaning.

    PubMed

    Rutala, William A; Weber, David J

    2011-03-01

    Failure to perform proper disinfection and sterilization of medical devices may lead to introduction of pathogens, resulting in infection. New techniques have been developed for achieving high-level disinfection and adequate environmental cleanliness. This article examines new technologies for sterilization and high-level disinfection of critical and semicritical items, respectively, and because semicritical items carry the greatest risk of infection, the authors discuss reprocessing semicritical items such as endoscopes and automated endoscope reprocessors, endocavitary probes, prostate biopsy probes, tonometers, laryngoscopes, and infrared coagulation devices. In addition, current issues and practices associated with environmental cleaning are reviewed. PMID:21315994

  18. [Antisepsis and disinfection: the necessity of a conceptual demarcation].

    PubMed

    Gröschel, D H; Kramer, A; Krasilnikow, A P; Spaulding, E H; Weuffen, W

    1989-09-01

    Increasing international cooperation in the areas of research, teaching, trade and healthcare has called for standardization of the terminology. In disinfection and antisepsis such efforts have been pursued for almost 20 years but without great success. This contribution to the definition of antisepsis and its clear separation from disinfection is supposed to promote international discussion. German terms for skin, mucosa and wound antisepsis are proposed which permit to restrict the term disinfection to the application of antimicrobial measures to inanimate objects and surfaces. PMID:2803452

  19. Disinfection of woollen blankets in steam at subatmospheric pressure

    PubMed Central

    Alder, V. G.; Gillespie, W. A.

    1961-01-01

    Blankets may be disinfected in steam at subatmospheric pressures by temperatures below boiling point inside a suitably adapted autoclave chamber. The chamber and its contents are thoroughly evacuated of air so as to allow rapid heat penetration, and steam is admitted to a pressure of 10 in. Hg below atmospheric pressure, which corresponds to a temperature of 89°C. Woollen blankets treated 50 times by this process were undamaged. Vegetative organisms were destroyed but not spores. The method is suitable for large-scale disinfection of blankets and for disinfecting various other articles which would be damaged at higher temperatures. PMID:13860203

  20. Photo-active float for field water disinfection.

    PubMed

    Shwetharani, R; Balakrishna, R Geetha

    2016-03-01

    The present study investigates the antibacterial activity of a photoactive float fabricated with visible light active N-F-TiO2 for the disinfection of field water widely contaminated with Gram positive and Gram negative bacteria like, Salmonella typhimurium (Gram negative), Escherichia coli (Gram negative), Staphylococcus aureus (Gram positive), Bacillus species (Gram positive), and Pseudomonas species (Gram negative). The antibacterial activity can be attributed to the unique properties of the photocatalyst, which releases reactive oxygen species in aqueous solution, under the illumination of sunlight. N-F-TiO2 nanoparticles efficiently photocatalyse the destruction of all the bacteria present in the contaminated water, giving clean water. The inactivation of bacteria is confirmed by a standard plate count method, MDA, RNA and DNA analysis. The purity of water was further validated by SPC indicating nil counts of bacteria after two days of storing and testing. The photocatalysts were characterized by XRD, BET measurement, SEM, EDX, UV-Vis and PL analysis. PMID:26924232

  1. Antimicrobial-Coated Granules for Disinfecting Water

    NASA Technical Reports Server (NTRS)

    Akse, James R.; Holtsnider, John T.; Kliestik, Helen

    2011-01-01

    Methods of preparing antimicrobialcoated granules for disinfecting flowing potable water have been developed. Like the methods reported in the immediately preceding article, these methods involve chemical preparation of substrate surfaces (in this case, the surfaces of granules) to enable attachment of antimicrobial molecules to the surfaces via covalent bonds. A variety of granular materials have been coated with a variety of antimicrobial agents that include antibiotics, bacteriocins, enzymes, bactericides, and fungicides. When employed in packed beds in flowing water, these antimicrobial-coated granules have been proven effective against gram-positive bacteria, gram-negative bacteria, fungi, and viruses. Composite beds, consisting of multiple layers containing different granular antimicrobial media, have proven particularly effective against a broad spectrum of microorganisms. These media have also proven effective in enhancing or potentiating the biocidal effects of in-line iodinated resins and of very low levels of dissolved elemental iodine.

  2. Chemical disinfection under conditions of microgravity

    NASA Astrophysics Data System (ADS)

    Marchin, George L.

    1997-01-01

    There is enormous potential for point-of-use water purifiers where central water treatment does not exist or distribution systems are faulty and allow incursion of pathogenic organisms after primary treatment. Manned space missions on the Space Shuttle and planned missions on the Space Station also employ point-of-use water purifiers termed microbial check valves (MCVs). Polyiodide resin materials in use on the Space Shuttle within the MCV and in terrestrial water purifiers, silver and copper chelex resins, zirconium peroxide chelex resin, and a quaternary ammonium compound-Dow Corning 5700-polymerized to carbon and polystyrene beads, were compared for disinfection ability. Experiments were conducted in fluid processing apparatus (FPAs) at unit gravity and in microgravity conditions aboard seven STS missions. These new materials may have applications in both space and terrestrial water treatment devices.

  3. DISINFECTION BY-PRODUCTS IN DRINKING WATER TREATMENT SYSTEMS

    EPA Science Inventory

    Due to concerns over trihalomethanes (THMs) and other halogenated by-products that can be formed during chlorination of drinking water, alternative disinfectants are being explored. Several drinking water treatment plants in the United States have altered their treatment methods...

  4. HYDRAULIC STUDIES AND CLEANING EVALUATIONS OF ULTRAVIOLET DISINFECTION UNITS

    EPA Science Inventory

    Various types of operating ultraviolet disinfection reactor designs were evaluated for hydraulic characteristics and cleaning requirements. The fluorocarbon polymer tube designs promote plug-flow behavior because of their relatively high length-to-diameter ratio. Hydraulic evalua...

  5. NONVOLATILE ORGANICS IN DISINFECTED WASTEWATER EFFLUENTS: CHEMICAL CHARACTERIZATION AND MUTAGENICITY

    EPA Science Inventory

    Principal objectives of this research program were to examine the effects of disinfection by chlorine, ozone, and ultraviolet light irradiation on nonvolatile organic constituents in secondary effluents relative to chemical effects and formation of mutagenic substances. In a comp...

  6. IDENTIFICATION OF NEW DISINFECTION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    Due to concern over the potential adverse health effects of trihalomethanes (THMs) and other chlorinated by-products in chlorinated drinking water, alternative disinfectants are being explored. Ozone, chlorine dioxide, and chloramine are popular alternatives, as they produce low...

  7. DISINFECTION OF WATER: DRINKING WATER, RECREATIONAL WATER, AND WASTEWATER

    EPA Science Inventory

    This chapter describes and categorizes the methodology used for disinfection of drinking water, recreational water and wastewater including wastewater sludges. It largely is a literature summary and references articles covering the years of 1939 through 1999, with a few reference...

  8. Effects of wastewater disinfection on waterborne bacteria and viruses

    USGS Publications Warehouse

    Blatchley, E. R., III; Gong, W.-L.; Alleman, J.E.; Rose, J.B.; Huffman, D.E.; Otaki, M.; Lisle, J.T.

    2007-01-01

    Wastewater disinfection is practiced with the goal of reducing risks of human exposure to pathogenic microorganisms. In most circumstances, the efficacy of a wastewater disinfection process is regulated and monitored based on measurements of the responses of indicator bacteria. However, inactivation of indicator bacteria does not guarantee an acceptable degree of inactivation among other waterborne microorganisms (e.g., microbial pathogens). Undisinfected effluent samples from several municipal wastewater treatment facilities were collected for analysis. Facilities were selected to provide a broad spectrum of effluent quality, particularly as related to nitrogenous compounds. Samples were subjected to bench-scale chlorination and dechlorination and UV irradiation under conditions that allowed compliance with relevant discharge regulations and such that disinfectant exposures could be accurately quantified. Disinfected samples were subjected to a battery of assays to assess the immediate and long-term effects of wastewater disinfection on waterborne bacteria and viruses. In general, (viable) bacterial populations showed an immediate decline as a result of disinfectant exposure; however, incubation of disinfected samples under conditions that were designed to mimic the conditions in a receiving stream resulted in substantial recovery of the total bacterial community. The bacterial groups that are commonly used as indicators do not provide an accurate representation of the response of the bacterial community to disinfectant exposure and subsequent recovery in the environment. UV irradiation and chlorination/dechlorination both accomplished measurable inactivation of indigenous phage; however, the extent of inactivation was fairly modest under the conditions of disinfection used in this study. UV irradiation was consistently more effective as a virucide than chlorination/dechlorination under the conditions of application, based on measurements of virus (phage

  9. CHARACTERIZING TOXICOLOGICALLY IMPORTANT DRINKING WATER DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Due to concerns over trihalomethanes (THMs) and other halogenated by-products that can be formed during chlorination of drinking water, alternative disinfectants are being explored. Several drinking water treatment plants in the United States have altered their treatment methods...

  10. USEPA Research on Monochloramine Disinfection Kinetics of Nitrosomonas Europaea

    EPA Science Inventory

    Based on utility surveys, 30 to 63% of utilities practicing chloramination for secondary disinfection experience nitrification episodes (American Water Works Association 2006). Nitrification in drinking water distribution systems is undesirable and may result in water quality deg...

  11. US EPA Research on Monochloramine Disinfection Kinetics of Nitrosomonas europaea

    EPA Science Inventory

    Based on utility surveys, 30 to 63% of utilities practicing chloramination for secondary disinfection experience nitrification episodes (American Water Works Association 2006). Nitrification in drinking water distribution systems is undesirable and may result in water quality deg...

  12. CONTROL OF OZONE DISINFECTION BY EXHAUST GAS MONITORING

    EPA Science Inventory

    In this paper it was demonstrated empirically that disinfection with ozone can be controlled by monitoring the exhaust gas ozone concentration exiting the contactor. This method is more reliable than measuring dissolved ozone because of the inherent difficulties and inadequacies ...

  13. In-office microwave disinfection of soft contact lenses

    SciTech Connect

    Harris, M.G.; Rechberger, J.; Grant, T.; Holden, B.A. )

    1990-02-01

    We evaluated the effectiveness of an in-office microwave disinfection procedure which allowed for the disinfection of up to 40 soft contact lenses at one time. Ciba AOSept cases filled with sterile unpreserved saline were contaminated with one of six FDA test challenge microorganisms at a concentration of approximately 10(3) colony forming units per milliliter (CFU/ml). Twenty cases were placed on the rotating plate of a standard 2450 MHz 650 W microwave oven in a 10-cm diameter circle. The cases were exposed to high intensity microwave irradiation for periods of 0 to 15 min. None of the 6 microorganisms evaluated survived 2 min or longer of microwave exposure. Our findings indicated that microwave irradiation can be a convenient, rapid, and effective method of disinfecting a number of soft contact lenses at one time and thus adaptable as an in-office soft contact lens disinfection procedure.

  14. Disinfection of low quality wastewaters by ultraviolet irradiation

    SciTech Connect

    Zukovs, G.; Kollar, J.; Monteith, H.D.; Ho, K.W.A.; Ross, S.A.

    1986-03-01

    Pilot-scale disinfection of simulated combined sewer overflow (CSO) by ultraviolet light (UV) and by high-rate chlorination were compared. Disinfection efficiency was evaluated over a range of dosages and contact times for fecal coliforms, enterococci, P. Aeruginosa, and Salmonella spp. Fecal coliform were reduced 3.0 to 3.2 logs at a UV dose of approximately 350,000..mu.. W s/cm/sup 2/. High-rate chlorination, at a contact time of 2.0 minutes and total residual chlorine concentration of approximately 25 mg/L (as Cl/sub 2/), reduced fecal coliforms by 4.0 logs. Pathogens were reduced to detection limits by both processes. Neither photoreactivation nor regrowth occurred int he disinfected effluents. The estimated capital costs of CSO disinfection by UV irradiation were consistently higher than for chlorination/dechlorination; operation and maintenance costs were similar. 19 references.

  15. IDENTIFICATION OF TI02/UV DISINFECTION BYPRODUCTS IN DRINKING WATER

    EPA Science Inventory

    Due to concern over the presence of trihalomethanes (THMs) and other chlorinated byproducts in chlorinated drinking water, alternative disinfection methods are being explored. One of the alternative treatment methods currently being evaluated for potential use with small systems ...

  16. HIGH-LEVEL OZONE DISINFECTION OF MUNICIPAL WASTEWATER EFFLUENTS

    EPA Science Inventory

    A 20 month operating experimental program was conducted at Marlborough, Massachusetts to evaluate the feasibility, engineering, and economic aspects of achieving high levels of effluent disinfection with ozone. The ozone research pilot facility was designed to operate at a consta...

  17. U.S. EPA's Ultraviolet Disinfection Technologies Demonstration Study

    EPA Science Inventory

    This presentation will give a background on USEPA's Disinfection Technologies Demonstration Study. This will include regulatory background, science background, goals of the project, and ultimate expected outcome of the project. This presentation will preceed a panel discussion ...

  18. A bottom up approach to implementing multi-purpose mitigation measures for reducing flood risk and improving water quality in agricultural catchments

    NASA Astrophysics Data System (ADS)

    Wilkinson, M. E.; Quinn, P. F.; Jonczyk, J.; Burke, S.; Nicholson, A.; Barber, N.; Owen, G.; Palmer, M.

    2012-04-01

    A number of studies have suggested that there is evidence that modern land-use management practices have increased surface runoff at the local scale. There is an urgent need for interventions to reduce the risk of flooding whilst also delivering multiple benefits (doing more for less). There are many settlements, which regularly suffer from flooding, which would benefit from upstream mitigation measures. Interventions at the source of runoff generation can have a positive impact on the flood hydrograph downstream. An integrated approach to managing runoff can also have multiple benefits on pollution and ecology, which could lead to beneficial impacts at the catchment scale. Belford, a small community in Northumberland, UK has suffered from an increased number of flood events over the past ten years. There is currently support within the English and Welsh Environment Agency for sustainable flood management solutions such as storage ponds, wetlands, beaver dams and willow riparian features which are being trialled at Belford. These runoff attenuation features (RAFs) also have benefits to water quality, capture sediment and create new ecological zones. Although the process by which numerous RAFs were deployed in Belford proved initially difficult to achieve within the existing regulatory framework, an efficient uptake process is now supported by local regulators including several branches of the Environment Agency. The Belford runoff management framework provides a step by step guide to implementing mitigation measures in the Belford burn catchment and could be easily applied to other catchments at a similar scale. The approach is based on implementing mitigation measures through engaging with catchment stakeholders and using solid field science and management protocols.

  19. The antibacterial properties of sodium hypochlorite and sodium dichloroisocyanurate as hospital disinfectants.

    PubMed

    Bloomfield, S F; Uso, E E

    1985-03-01

    The antibacterial activity of unbuffered sodium dichloroisocyanurate (NaDCC) (pH 6.6) and of sodium hypochlorite (NaOCl) buffered to pH 7.2, 9.0 and 10.6 was compared. Under clean conditions, solutions of NaDCC at pH 6.6 or NaOCl at pH 7.2 and 9.0 with 100-200 mg l-1 available chlorine showed satisfactory disinfectant activity against vegetative bacteria. Sporicidal action required higher concentrations of both agents, and NaOCl at pH 7.2 showed most activity. In the presence of organic matter NaDCC offers significant advantages over NaOCl, a 3000 mg l-1 solution of NaDCC giving satisfactory activity in the presence of plasma concentrations up to 20% v/v compared with NaOCl solutions at pH 7.2, 9.0 and 10.6 which were inactivated at chlorine concentrations up to 5000 mg l-1. Although NaOCl pH 10.6 showed satisfactory disinfectant activity under clean conditions, our results indicate that formulations at this pH should not be used where sporicidal action is required or where substantial organic soiling is anticipated. PMID:2859319

  20. Equivalency testing of ultraviolet disinfection for wastewater reclamation

    SciTech Connect

    Oppenheimer, J.A.; Jacangelo, J.G.; Laine, J.M.

    1996-11-01

    UV light disinfection was shown to continuously provide microbial inactivation equivalent to chlorine while reducing the formation of known carcinogenic disinfection by-products and the formation of chronic whole effluent toxicity. This was the first study to demonstrate UV`s performance relative to chlorination over an extended timeframe at a full-scale facility treating to meet the most stringent California reclamation standards.

  1. The effectiveness of photocatalytic ionisation disinfection of filter materials.

    PubMed

    Pietrzak, Katarzyna; Gutarowska, Beata

    2013-01-01

    The purpose of this study was to determine the effectiveness of photocatalytic ionisation as a disinfection method for filter materials contaminated by microorganisms, and to assess how air relative humidity (RH), time and microbe type influence the effectiveness of this disinfection. In the quantitative analysis of a used car air filter, bacterial contamination equalled 1.2 x 10(5) cfu/cm2, fungal contamination was 3.8 x 10(6) cfu/cm2, and the isolated microorganisms were Aspergillus niger, Bacillus megaterium, Cladosporium herbarum, Cryptococcus laurenti, Micrococcus sp., Rhodotorula glutinis and Staphylococcus cohnii. In the model experiment, three isolates (C. herbarum, R. glutinis, S. cohnii) and 3 ATCC species (A. niger, E. coli, S. aureus) were used for photocatalytic ionisation disinfection. The conditions of effective photocatalytic ionisation disinfection (R > or = 99.9%) were established as 2-3 h at RH = 77% (bacteria) and 6-24 h at RH = 53% (fungi). RH has an influence on the effectiveness of the photocatalytic disinfection process; the highest effectiveness was obtained for bacteria at RH = 77%, with results 5% higher than for RH = 49%. The studies show that the sensitivity of microorganisms to photocatalytic ionisation disinfection is ordered as follows: Gram-positive bacteria (S. cohnii, S. aureus), Gram-negative bacteria (E. coli), yeasts (R. glutinis), and moulds (C. herbarum, A. niger). Of all the mathematical models used for the description of death dynamics after photocatalytic ionisation disinfection, the Chick-Watson model is the most useful, but for more resistant microorganisms, the delayed Chick-Watson model is highly recommended. It therefore seems, that the presented disinfection method of photocatalytic ionisation can be successfully used to clean filtration materials. PMID:24053016

  2. Decontamination of Bacillus anthracis Spores: Evaluation of Various Disinfectants

    PubMed Central

    Heninger, Sara J.; Anderson, Christine A.; Beltz, Gerald; Onderdonk, Andrew B.

    2009-01-01

    The present study compares the efficacy of various disinfectants against Bacillus anthracis spores. While Bleach Rite® and 10% bleach reduce spore numbers by 90% within 10 minutes, a long contact time is required for complete disinfection. By contrast, although SporGon® did not initially reduce the number of spores as quickly as Bleach Rite or 10% bleach, shorter contact times were required for complete eradication of viable spores. PMID:20967138

  3. An in-use microbiological comparison of two surgical hand disinfection techniques in cardiothoracic surgery: hand rubbing versus hand scrubbing.

    PubMed

    Carro, C; Camilleri, L; Traore, O; Badrikian, L; Legault, B; Azarnoush, K; Dualé, C; De Riberolles, C

    2007-09-01

    Surgical site infection after heart surgery increases morbidity and mortality. The method of presurgical hand disinfection could influence the infection risk. From February to April 2003, we compared the microbiological efficacy of hand-rubbing (R) and hand-scrubbing (S) procedures. The surgical team alternately used hand-scrubbing or hand-rubbing techniques every two weeks. Fingertip impressions were taken before and immediately after hand disinfection, every 2h and at the end of the operation. Acceptability of hand rubbing was assessed by a questionnaire. Mean durations of surgical procedures were 259+/-68 and 244+/-69min for groups S and R respectively (P=0.43). Bacterial counts immediately after hand disinfection were comparable with the two techniques, but significantly lower in group R at the end of surgery. No differences were observed between the percentages of negative samples taken after 2h, 4h and at the end of surgery between the two groups. Bacterial skin flora reduction immediately after hand disinfection, after 2h and 4h of operating time and at the end of surgery was better in group R, but the difference was not statistically significant. Before surgery, the hand-rubbing method with alcohol solution preceded by hand washing with mild neutral soap is as effective as hand scrubbing to reduce bacterial counts on hands. It decreased the bacterial counts both immediately after hand disinfection and at the end of long cardiothoracic surgical procedures. The acceptability of hand rubbing was excellent and it can be considered to be a valid alternative to the conventional hand-scrubbing protocol. PMID:17719131

  4. Deposition and disinfection of Escherichia coli O157:H7 on naturally occurring photoactive materials in a parallel plate chamber†

    PubMed Central

    Taylor, Alicia A.; Chowdhury, Indranil; Gong, Amy S.; Cwiertny, David M.; Walker, Sharon L.

    2014-01-01

    Dissolved organic matter in combination with iron oxides has been shown to facilitate photochemical disinfection through the production of reactive oxygen species (ROS) under UV and visible light. However, due to the extremely short lifetime of these radicals, the disinfection effciency is limited by the successful transport of ROS to bacterial surfaces. This study was designed to quantitatively investigate three collector surfaces with various potentials to produce ROS [bare quartz, hematite (α-Fe2O3) coated quartz, and Suwannee River humic acid (SRHA)] and the effects of extracellular polymeric substance (EPS) (full or partial coating) and solution chemistry (ionic strength, IS) on the interactions between bacteria and the ROS-producing substrates. With few exceptions, bacterial deposition studies in a parallel plate (PP) flow chamber have revealed increasing cell adhesion with IS. Furthermore, interactions between collector surfaces and cells can be explained by electrostatic forces, with negatively charged SRHA reducing and positively charged α-Fe2O3 enhancing bacterial deposition significantly. Increased deposition was also observed with full EPS content, indicating the ability of EPS to facilitate interaction between cells and surfaces in the aquatic environment. In complementary disinfection studies conducted with simulated light, viability loss was observed for cells fully coated with EPS when attached to α-Fe2O3 under all IS conditions. Based upon our prior study in which EPS was found to not inhibit hydroxyl radical activity toward bacteria, we proposed that EPS might therefore promote disinfection by facilitating cell attachment to ROS-producing surfaces where higher concentrations of ROS are expected at closer proximities to reactive substrates (e.g., SRHA and α-Fe2O3). Our findings on the mechanism and controlling factors of cell interactions with photoactive substrates provide insight as to the role of ionic strength in photochemical disinfection

  5. Characterization of the microbial flora in disinfecting footbaths with hypochlorite.

    PubMed

    Langsrud, Solveig; Seifert, Linn; Møretrø, Trond

    2006-09-01

    Change or disinfection of footwear are measures to prevent cross contamination between areas with low and high hygienic levels in the food industry. The efficacy of disinfecting footwear is not well documented. Samples of used disinfectant and from swabbing of corners after draining were taken from disinfecting footbaths containing chlorine in four Norwegian cheese factories. Bacteria were present in 9 of 12 footbaths and more positive samples were found from swab samples than from used disinfectant. The microbial flora in footbaths varied between the dairies. In two dairies, the flora was dominated by Pseudomonas spp. and Acinetobacter spp., respectively. In the third dairy, both Bacillus spp. and Staphylococcus spp. were present and in the fourth dairy, the flora was diverse (Acinetobacter sp., Enterococcus faecalis, Klebsiella pneumoniae, and Bacillus sp.). The strains were not resistant to the recommended user concentration of chlorine in bactericidal suspension or surface tests. The degree of attachment to plastic varied between strains and species and bacteria attached to surfaces were in general more resistant than suspended bacteria. The results of the survey indicated that disinfecting footbaths containing chlorine may act as contamination sources in food factories and should not be used without regular hygienic monitoring. PMID:16995523

  6. Disinfection of Needleless Connector Hubs: Clinical Evidence Systematic Review

    PubMed Central

    Moureau, Nancy L.

    2015-01-01

    Background. Needleless connectors (NC) are used on virtually all intravascular devices, providing an easy access point for infusion connection. Colonization of NC is considered the cause of 50% of postinsertion catheter-related infections. Breaks in aseptic technique, from failure to disinfect, result in contamination and subsequent biofilm formation within NC and catheters increasing the potential for infection of central and peripheral catheters. Methods. This systematic review evaluated 140 studies and 34 abstracts on NC disinfection practices, the impact of hub contamination on infection, and measures of education and compliance. Results. The greatest risk for contamination of the catheter after insertion is the NC with 33–45% contaminated, and compliance with disinfection as low as 10%. The optimal technique or disinfection time has not been identified, although scrubbing with 70% alcohol for 5–60 seconds is recommended. Studies have reported statistically significant results in infection reduction when passive alcohol disinfection caps are used (48–86% reduction). Clinical Implications. It is critical for healthcare facilities and clinicians to take responsibility for compliance with basic principles of asepsis compliance, to involve frontline staff in strategies, to facilitate education that promotes understanding of the consequences of failure, and to comply with the standard of care for hub disinfection. PMID:26075093

  7. Stability and effectiveness of chlorine disinfectants in water distribution systems

    SciTech Connect

    Olivieri, V.P.; Snead, M.C.; Kruse, C.W.; Kawata, K.

    1986-11-01

    A test system for water distribution was used to evaluate the stability and effectiveness of three residual disinfectants - free chlorine, combined chlorine, and chlorine dioxide - when challenged with a sewage contaminant. The test distribution system consisted of the street main and internal plumbing for two barracks at Fort George G. Meade, MD. To the existing pipe network, 152 m (500 ft) of 13-mm (0.5 in.) copper pipe were added for sampling, and 60 m (200 ft) of 2.54-cm (1.0 in.) plastic pipe were added for circulation. The levels of residual disinfectants tested were 0.2 mg/L and 1.0 mg/L as available chlorine. In the absence of a disinfectant residual, microorganisms in the sewage contaminant were consistently recovered at high levels. The presence of any disinfectant residual reduced the microorganism level and frequency of occurrence at the consumer's tap. Free chlorine was the most effective residual disinfectant and may serve as a marker or flag in the distribution network. Free chlorine and chlorine dioxide were the least stable in the pipe network. The loss of disinfectant in the pipe network followed first-order kinetics. The half-life determined in static tests for free chlorine, chlorine dioxide, and combined chlorine was 140, 93, and 1680 min.

  8. Stability and effectiveness of chlorine disinfectants in water distribution systems.

    PubMed Central

    Olivieri, V P; Snead, M C; Krusé, C W; Kawata, K

    1986-01-01

    A test system for water distribution was used to evaluate the stability and effectiveness of three residual disinfectants--free chlorine, combined chlorine, and chlorine dioxide--when challenged with a sewage contaminant. The test distribution system consisted of the street main and internal plumbing for two barracks at Fort George G. Meade, MD. To the existing pipe network, 152 m (500 ft) of 13-mm (0.5 in.) copper pipe were added for sampling, and 60 m (200 ft) of 2.54-cm (1.0 in.) plastic pipe were added for circulation. The levels of residual disinfectants tested were 0.2 mg/L and 1.0 mg/L as available chlorine. In the absence of a disinfectant residual, microorganisms in the sewage contaminant were consistently recovered at high levels. The presence of any disinfectant residual reduced the microorganism level and frequency of occurrence at the consumer's tap. Free chlorine was the most effective residual disinfectant and may serve as a marker or flag in the distribution network. Free chlorine and chlorine dioxide were the least stable in the pipe network. The loss of disinfectant in the pipe network followed first-order kinetics. The half-life determined in static tests for free chlorine, chlorine dioxide, and combined chlorine was 140, 93, and 1680 min. PMID:3028767

  9. SAFER STERILE COMPOUNDING: Choosing and Using Disinfectants for the Cleanroom.

    PubMed

    Kastango, Eric S; Douglass, Kate; Patel, Kedar; Givehchi, Babak; Brister, Paul; Postlewaite, Jay; Taraban, Laura

    2015-01-01

    Compounders worldwide are responsible for ensuring that the sterile preparations they dispense are pure, potent, and safe. To achieve that result, proper cleaning and disinfection of International Organization for Standardization controlled environments must occur. Because those tasks must be performed according to established standards, the compounding pharmacist must research regulatory requirements and appropriate products for use. In this report, we focus on U.S. regulations, guiding entities, and effective products that enable compliance with the increasingly stringent procedures required for pharmaceutical compounding. We also review cleaning and disinfecting processes, discuss the importance of correctly choosing and using disinfectants and/ or sporicidal disinfectants with surface claims in the cleanroom, and provide answers to questions frequently asked by staff who use those agents. In addition, we profile specific disinfectants that are compliant with UnitedStates Pharmacopeia Chapter <797> and current good manufacturing practice standards. Biological safety cabinets and compounding aseptic containment isolators must undergo an additional process that deactivates hazardous drug residues and removes them from the interior surfaces of those devices before they are cleaned and disinfected, but that discussion is beyond the scope of this article. PMID:26625562

  10. Effect of the disinfection agents chlorine, UV irradiation, silver ions, and TiO2 nanoparticles/near-UV on DNA molecules.

    PubMed

    Van Aken, Benoit; Lin, Lian-Shin

    2011-01-01

    Extracellular DNA in municipal wastewater and effluents from hospitals and R&D laboratories contains antimicrobial resistance and recombinant genes that are today considered as a new class of emerging contaminants. The objective of this research was to investigate the effect of disinfection agents on the integrity of DNA molecules by using real-time PCR. Escherichia coli cell suspensions and genomic DNA in aqueous solution were exposed to increasing doses of disinfection systems, including chlorination, UV irradiation, silver ions, and TiO2 nanoparticles/near-UV. The doses resulting in damage of DNA (16S rDNA) were determined using real-time PCR and compared with the doses resulting in the inactivation of bacterial cells. Our results showed that the disinfection agents chlorine, UV, and silver significantly inhibited the amplification of a fragment of 16S rDNA, but only when applied at doses much higher than the lethal doses for E. coli bacteria. The inactivation doses of TiO2 nanoparticles/near-UV were of the same order of magnitude for both DNA and living cells. Our results raise questions about the efficacy of disinfection processes to destroy and prevent the dispersion of DNA pollutants into the environment. In addition, the damage of DNA by high levels of disinfectants may have implications for the utilization of PCR-based methods for bacterial detection. PMID:22214074

  11. Efficient Photocatalytic Disinfection of Escherichia coli O157:H7 using C70-TiO2 Hybrid under Visible Light Irradiation

    PubMed Central

    Ouyang, Kai; Dai, Ke; Walker, Sharon L.; Huang, Qiaoyun; Yin, Xixiang; Cai, Peng

    2016-01-01

    Efficient photocatalytic disinfection of Escherichia coli O157:H7 was achieved by using a C70 modified TiO2 (C70-TiO2) hybrid as a photocatalyst under visible light (λ > 420 nm) irradiation. Disinfection experiments showed that 73% of E. coli O157:H7 died within 2 h with a disinfection rate constant of k = 0.01 min−1, which is three times that measured for TiO2. The mechanism of cell death was investigated by using several scavengers combined with a partition system. The results revealed that diffusing hydroxyl radicals play an important role in the photocatalytically initiated bacterial death, and direct contact between C70-TiO2 hybrid and bacteria is not indispensable in the photocatalytic disinfection process. Extracellular polymeric substances (EPS) of bacteria have little effect on the disinfection efficiency. Analyses of the inhibitory effect of C70-TiO2 thin films on E. coli O157:H7 showed a decrease of the bacterial concentration from 3 × 108 to 38 cfu mL−1 in the solution with C70-TiO2 thin film in the first 2 h of irradiation and a complete inhibition of the growth of E. coli O157:H7 in the later 24 h irradiation. PMID:27161821

  12. Efficient Photocatalytic Disinfection of Escherichia coli O157:H7 using C70-TiO2 Hybrid under Visible Light Irradiation.

    PubMed

    Ouyang, Kai; Dai, Ke; Walker, Sharon L; Huang, Qiaoyun; Yin, Xixiang; Cai, Peng

    2016-01-01

    Efficient photocatalytic disinfection of Escherichia coli O157:H7 was achieved by using a C70 modified TiO2 (C70-TiO2) hybrid as a photocatalyst under visible light (λ > 420 nm) irradiation. Disinfection experiments showed that 73% of E. coli O157:H7 died within 2 h with a disinfection rate constant of k = 0.01 min(-1), which is three times that measured for TiO2. The mechanism of cell death was investigated by using several scavengers combined with a partition system. The results revealed that diffusing hydroxyl radicals play an important role in the photocatalytically initiated bacterial death, and direct contact between C70-TiO2 hybrid and bacteria is not indispensable in the photocatalytic disinfection process. Extracellular polymeric substances (EPS) of bacteria have little effect on the disinfection efficiency. Analyses of the inhibitory effect of C70-TiO2 thin films on E. coli O157:H7 showed a decrease of the bacterial concentration from 3 × 10(8) to 38 cfu mL(-1) in the solution with C70-TiO2 thin film in the first 2 h of irradiation and a complete inhibition of the growth of E. coli O157:H7 in the later 24 h irradiation. PMID:27161821

  13. Comparison of efficacy of herbal disinfectants with chlorhexidine mouthwash on decontamination of toothbrushes: An experimental trial

    PubMed Central

    Anand, P. J. Swathy; Athira, S.; Chandramohan, Sabari; Ranjith, K.; Raj, V. Veena; Manjula, V. D.

    2016-01-01

    Background: Toothbrushes in regular use can become heavily contaminated with microorganisms, which can cause infection or reinfection. There is a need for toothbrush disinfection methods, which are rapidly effective, cost-effective, nontoxic, and that can be easily implemented. Aim: To compare the efficacy of 3% neem, garlic of concentration 4.15 mg/mL and green tea of concentration 40 mg/mL with 0.2% chlorhexidine mouthwash as toothbrush disinfectants. Materials and Methods: The study was a parallel in vitro comparative experimental trial conducted among 75 randomly selected boys aged between 18 years and 21 years. The subjects were divided into five groups, namely, Group I, Group II, Group III, Group IV, and Group V. They were provided with a new set of precoded toothbrushes and nonfluoridated tooth pastes. After 14 days of tooth brushing, the toothbrushes were immersed in antimicrobial solution for 12 h [Group I––distilled water (control), Group II––3% neem, Group III––garlic of concentration 4.15 mg/mL, Group IV––green tea of concentration 40 mg/mL, and Group V––0.2% chlorhexidine] and then subjected to microbial analysis to check the presence of Streptococcus mutans. The t-test and analysis of variance (ANOVA) were done using Statistical Package for the Social Sciences (SPSS) software version 16. Results: All test solutions showed a statistically significant reduction of Streptococcus mutans count (P < 0.001). There was no statistical difference between the efficacies of neem, garlic, and green tea when compared with chlorhexidine mouthwash (P > 0.05). Conclusion: Neem, garlic, and green tea are equally efficacious as chlorhexidine and these herbal products can be used as potent alternatives to chlorhexidine as disinfectant for toothbrushes. PMID:27011928

  14. A MULTIPLE-PURPOSE DESIGN APPROACH TO THE EVALUATION OF RISKS FROM COMPLEX MIXTURES OF DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Drinking water disinfection has effectively eliminated much of the morbidity and mortality associated with waterborne infectious diseases in the United States. Various disinfection processes, however, produce certain types and amounts of disinfection by-products (DBPs), including...

  15. Disinfection and Sterilization in Health Care Facilities: An Overview and Current Issues.

    PubMed

    Rutala, William A; Weber, David J

    2016-09-01

    When properly used, disinfection and sterilization can ensure the safe use of invasive and noninvasive medical devices. The method of disinfection and sterilization depends on the intended use of the medical device: critical items (contact sterile tissue) must be sterilized before use; semicritical items (contact mucous membranes or nonintact skin) must be high-level disinfected; and noncritical items (contact intact skin) should receive low-level disinfection. Cleaning should always precede high-level disinfection and sterilization. Current disinfection and sterilization guidelines must be strictly followed. PMID:27515140

  16. An application of the Multi-Purpose System Simulation /MPSS/ model to the Monitor and Control Display System /MACDS/ at the National Aeronautics and Space Administration /NASA/ Goddard Space Flight Center /GSFC/

    NASA Technical Reports Server (NTRS)

    Mill, F. W.; Krebs, G. N.; Strauss, E. S.

    1976-01-01

    The Multi-Purpose System Simulator (MPSS) model was used to investigate the current and projected performance of the Monitor and Control Display System (MACDS) at the Goddard Space Flight Center in processing and displaying launch data adequately. MACDS consists of two interconnected mini-computers with associated terminal input and display output equipment and a disk-stored data base. Three configurations of MACDS were evaluated via MPSS and their performances ascertained. First, the current version of MACDS was found inadequate to handle projected launch data loads because of unacceptable data backlogging. Second, the current MACDS hardware with enhanced software was capable of handling two times the anticipated data loads. Third, an up-graded hardware ensemble combined with the enhanced software was capable of handling four times the anticipated data loads.

  17. Surface Charge and Hydrophobicity of Endospores of Bacillus anthracis and Related Species in Aqueous Solution

    EPA Science Inventory

    The surface properties of microorganisms play an important role in attachment and detachment in the environment. The change in surface charge can effect coagulation, disinfection, adhesion to surfaces, uptake of chemicals, and environmental transport. In aqueous solution, cell s...

  18. Efficacy of dental unit waterlines disinfectants on a polymicrobial biofilm.

    PubMed

    Costa, Damien; Girardot, Marion; Bertaux, Joanne; Verdon, Julien; Imbert, Christine

    2016-03-15

    Due to their high surface-volume ratio, their laminar flow and frequent stagnation periods, dental unit waterlines (DUWL) foster the attachment of microorganisms and the development of biofilm, resulting in the continuous contamination of the outlet water from dental units; this contamination may be responsible for a potential risk of infection due to the exposure of patients and medical staff to droplet inhalation or splashed water. In this study, the anti-biofilm activity of three disinfectants recommended by dental unit manufacturers -Calbenium(©), Oxygenal 6(©) and Sterispray(©) - was evaluated. A dynamic model simulating DUWL conditions was developed and polymicrobial biofilms containing bacteria (Pseudomonas aeruginosa), fungi (Candida albicans) and Free Living Amoeba (FLA: Vermamoeba vermiformis) were allowed to form. The ability of disinfectants to reduce biofilm formation or to eradicate an already formed biofilm was evaluated. Results showed the various effects of the tested disinfectants according to their composition, concentration and the targeted species. V. vermiformis was resistant to disinfectants, regardless of the tested concentrations and the concentrations recommended by manufacturers were not the most appropriate. Results also showed that Calbenium(©) was the most effective disinfectant to reduce already formed biofilms; its maximum efficiency was observed from 0.5% on both P. aeruginosa and C. albicans compared to 2 and 3% respectively for Sterispray(©). The maximum efficiency of Oxygenal(©) was observed from 3% on P. aeruginosa but Oxygenal(©) was unable to totally eliminate C. albicans in the tested conditions, contrary to other disinfectants. Calbenium(©) was able to prevent biofilm formation efficiently even if it displayed no prophylactic activity against V. vermiformis. Overall, the FLA survival may contribute to maintaining other species. Finally the tested disinfectants were partially active against sessile microorganisms

  19. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell.

    PubMed

    Huang, Xiao; Qu, Yan; Cid, Clément A; Finke, Cody; Hoffmann, Michael R; Lim, Keahying; Jiang, Sunny C

    2016-04-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source. PMID:26854604

  20. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell

    PubMed Central

    Huang, Xiao; Qu, Yan; Cid, Clément A.; Finke, Cody; Hoffmann, Michael R.; Lim, Keahying; Jiang, Sunny C.

    2016-01-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [•OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source. PMID:26854604

  1. Novel Electrokinetic Microfluidic Detector for Evaluating Effectiveness of Microalgae Disinfection in Ship Ballast Water.

    PubMed

    Maw, Myint Myint; Wang, Junsheng; Li, Fabo; Jiang, Jinhu; Song, Younan; Pan, Xinxiang

    2015-01-01

    Ship ballast water treatment methods face many technical challenges. The effectiveness of every treatment method usually is evaluated by using large scale equipment and a large volume of samples, which involves time-consuming, laborious, and complex operations. This paper reports the development of a novel, simple and fast platform of methodology in evaluating the efficiency and the best parameters for ballast water treatment systems, particularly in chemical disinfection. In this study, a microfluidic chip with six sample wells and a waste well was designed, where sample transportation was controlled by electrokinetic flow. The performance of this microfluidic platform was evaluated by detecting the disinfection of Dunaliella salina (D. salina) algae in ballast water treated by sodium hypochlorite (NaClO) solution. Light-induced chlorophyll fluorescence (LICF) intensity was used to determine the viability of microalgae cells in the system, which can be operated automatically with the dimension of the detector as small as 50 mm × 24 mm × 5 mm. The 40 µL volume of sample solution was used for each treatment condition test and the validity of detection can be accomplished within about five min. The results show that the viability of microalgae cells under different treatment conditions can be determined accurately and further optimal treatment conditions including concentrations of NaClO and treatment time can also be obtained. These results can provide accurate evaluation and optimal parameters for ballast water treatment methods. PMID:26516836

  2. Novel Electrokinetic Microfluidic Detector for Evaluating Effectiveness of Microalgae Disinfection in Ship Ballast Water

    PubMed Central

    Maw, Myint Myint; Wang, Junsheng; Li, Fabo; Jiang, Jinhu; Song, Younan; Pan, Xinxiang

    2015-01-01

    Ship ballast water treatment methods face many technical challenges. The effectiveness of every treatment method usually is evaluated by using large scale equipment and a large volume of samples, which involves time-consuming, laborious, and complex operations. This paper reports the development of a novel, simple and fast platform of methodology in evaluating the efficiency and the best parameters for ballast water treatment systems, particularly in chemical disinfection. In this study, a microfluidic chip with six sample wells and a waste well was designed, where sample transportation was controlled by electrokinetic flow. The performance of this microfluidic platform was evaluated by detecting the disinfection of Dunaliella salina (D. salina) algae in ballast water treated by sodium hypochlorite (NaClO) solution. Light-induced chlorophyll fluorescence (LICF) intensity was used to determine the viability of microalgae cells in the system, which can be operated automatically with the dimension of the detector as small as 50 mm × 24 mm × 5 mm. The 40 µL volume of sample solution was used for each treatment condition test and the validity of detection can be accomplished within about five min. The results show that the viability of microalgae cells under different treatment conditions can be determined accurately and further optimal treatment conditions including concentrations of NaClO and treatment time can also be obtained. These results can provide accurate evaluation and optimal parameters for ballast water treatment methods. PMID:26516836

  3. Disinfection efficacy of sodium dichloroisocyanurate (NADCC) against common food-borne intestinal protozoa.

    PubMed

    El Zawawy, Lobna A; El-Said, Doaa; Ali, Safia M; Fathy, Fouad M

    2010-04-01

    The present study was conducted to investigate the efficacy of sodium dichloroisocyanurate (NaDCC) on the infective stages of common food-borne intestinal protozoa; Entamoeba histolytica (E. histolytica), Giardia lamblia (G. lamblia), Cryptosporidium, Cyclospora and Microsporidia; beside its effect on raw green vegetables and fruits. Parasites, isolated from stool of patients with diarrhea or dysentery, were exposed to NaDCC solution (1g/l) for one and two hours. Disinfection effect of NaDCC was assessed by in-vitro viability, using trypan blue stain, and infectivity bioassay in laboratory animals as indicated by fecal and intestinal parasitic counts. Raw vegetables and fruits were dipped in NaDCC solution in the same concentration and exposure time as used for treatment of the parasites. Results revealed statistically significant reductions in viability and infectivity of all examined parasites indicating their susceptibility to NaDCC. Relative variations in susceptibility were revealed; E. histolytica and G. lamblia were most susceptible (100% reduction) followed by Microsporidia then Cryptospridium and Cyclospora. NaDCC did not affect the consistency, color, taste or flavor of raw green vegetables and fruits. The proved efficacy of NaDCC, in cheap and convenient dry tablet form, makes it a promising tool in decontaminating raw vegetables and fruits from food-borne protozoan parasites at household and restaurant levels as well as in catering and fresh produce industry. It is also recommended for disinfection of food preparation surfaces and equipment. PMID:20503596

  4. [Specific antisepsis and environmental disinfection in preventing "Clostridium difficile associated diarrhea"].

    PubMed

    Agolini, G; Protano, C; Puro, V; Raitano, A; Ferraro, F; Vitali, M

    2009-01-01

    In the last years, Clostridium difficile acquired great interest for public health because of constant increase of Clostridium difficile associated diarrhea (CDAD), especially in nosocomial field and as a consequences of its pathogenicity and virulence. Oro-faecal transmission and great environmental persistence of Clostridium difficile indicate hand hygiene of health care workers and environmental disinfection practices as key interventions for prevention and control of nosocomial CDAD. The current indications relative to the hand hygiene suggest the use of soap and water for hand washing and, to achieve a better compliance of health care workers to this treatment, the alternative use of sodium dichloroisocyanurate or alcohol-based solution or gel waterless. Regard to environmental disinfection, to avoid high concentrations of sodium hypochlorite (in the magnitude of 5.000-6.000 ppm), necessary to reduce microbic load of dirty environment, the most appropriate treatment should consist of 2 phases: preliminary cleaning with water and detergents or polyphenol, followed by treatment with solution containing 1.000 ppm available chlorine, obtained from sodium hypochlorite or sodium dichloroisocyanurate. PMID:20169831

  5. Determination of decimal reduction time (D value) of chemical agents used in hospitals for disinfection purposes

    PubMed Central

    Mazzola, Priscila Gava; Penna, Thereza Christina Vessoni; da S Martins, Alzira M

    2003-01-01

    Background Prior to the selection of disinfectants for low, intermediate and high (sterilizing) levels, the decimal reduction time, D-value, for the most common and persistent bacteria identified at a health care facility should be determined. Methods The D-value was determined by inoculating 100 mL of disinfecting solution with 1 mL of a bacterial suspension (104 – 105 CFU/mL for vegetative and spore forms). At regular intervals, 1 mL aliquots of this mixture were transferred to 8 mL of growth media containing a neutralizing agent, and incubated at optimal conditions for the microorganism. Results The highest D-values for various bacteria were determined for the following solutions: (i) 0.1% sodium dichloroisocyanurate (pH 7.0) – E. coli and A. calcoaceticus (D = 5.9 min); (ii) sodium hypochlorite (pH 7.0) at 0.025% for B. stearothermophilus (D = 24 min), E. coli and E. cloacae (D = 7.5 min); at 0.05% for B. stearothermophilus (D = 9.4 min) and E. coli (D = 6.1 min) and 0.1% for B. stearothermophilus (D = 3.5 min) and B. subtilis (D = 3.2 min); (iii) 2.0% glutaraldehyde (pH 7.4) – B. stearothermophilus, B. subtilis (D = 25 min) and E. coli (D = 7.1 min); (iv) 0.5% formaldehyde (pH 6.5) – B. subtilis (D = 11.8 min), B. stearothermophilus (D = 10.9 min) and A. calcoaceticus (D = 5.2 min); (v) 2.0% chlorhexidine (pH 6.2) – B. stearothermophilus (D = 9.1 min), and at 0.4% for E. cloacae (D = 8.3 min); (vi) 1.0% Minncare® (peracetic acid and hydrogen peroxide, pH 2.3) – B. stearothermophilus (D = 9.1 min) and E. coli (D = 6.7 min). Conclusions The suspension studies were an indication of the disinfectant efficacy on a surface. The data in this study reflect the formulations used and may vary from product to product. The expected effectiveness from the studied formulations showed that the tested agents can be recommended for surface disinfection as stated in present guidelines and emphasizes the importance and need to develop routine and novel programs to

  6. Designing plasmas for chronic wound disinfection

    NASA Astrophysics Data System (ADS)

    Nosenko, T.; Shimizu, T.; Morfill, G. E.

    2009-11-01

    Irradiation with low-temperature atmospheric-pressure plasma provides a promising method for chronic wound disinfection. To be efficient for this purpose, plasma should meet the following criteria: it should significantly reduce bacterial density in the wounded area, cause a long-term post-irradiation inhibition of bacterial growth, yet without causing any negative effect on human cells. In order to design plasmas that would satisfy these requirements, we assessed the relative contribution of different components with respect to bactericidal properties due to irradiation with argon plasma. We demonstrate that plasma-generated UV radiation is the main short-term sterilizing factor of argon plasma. On the other hand, plasma-generated reactive nitrogen species (RNS) and reactive oxygen species (ROS) cause a long-term 'after-irradiation' inhibition of bacterial growth and, therefore, are important for preventing wound recolonization with bacteria between two treatments. We also demonstrate that at certain concentrations plasma-generated RNS and ROS cause significant reduction of bacterial density, but have no adverse effect on human skin cells. Possible mechanisms of the different effects of plasma-generated reactive species on bacteria and human cells are discussed. The results of this study suggest that argon plasma for therapeutic purposes should be optimized in the direction of reducing the intensity of plasma-generated UV radiation and increasing the density of non-UV plasma products.

  7. MULTISPECTRAL IDENTIFICATION OF CHLORINE DIOXIDE DISINFECTION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    This paper discusses the identification of organic disinfection by-products (DBPs) at a pilot plant in Evansville, Indiana, that uses chlorine dioxide as a primary disinfectant. nconventional multispectral identification techniques (gas chromatography combined with high and low r...

  8. The Occurrence and Comparative Toxicity of Haloacetaldehyde Disinfection Byproducts in Drinking Water

    EPA Science Inventory

    The introduction of drinking water disinfection greatly reduced the incidence of waterborne diseases. However, the reaction between disinfectants and natural organic matter in the source water can lead to an unintended consequence, which is the formation of drinking water disinfe...

  9. RESEARCH PLAN FOR MICROBIAL PATHOGENS AND DISINFECTION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    This research plan was developed to describe research needed to support EPA's development of drinking water regulations concerning disinfectants, disinfection by-products (DBPs) and microbial pathogens, focusing on key scientific and technical information needed. The research pl...

  10. IDENTIFICATION OF CHLORINE DIOXIDE AND CHLORAMINE DRINKING WATER DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    Due to concern over the potential adverse health effects of trihalomethanes (THMs) and other chlorinated by-products in chlorinated drinking water, alternative disinfection methods are being explored. Chlorine dioxide and chloramine are two popular alternative disinfectants, with...

  11. RESEARCH PLAN FOR MICROBIAL PATHOGENS AND DISINFECTION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    This research plan was developed to describe research needed to support EPAs development of drinking water regulations concerning disinfectants, disinfection by-products (DBPs) and microbial pathogens, focusing on key scientific and technical information needed. The research plan...

  12. ORD RESEARCH PLAN FOR MICROBIAL PATHOGENS AND DISINFECTION BY-PRODUCTS IN DRINKING WATER

    EPA Science Inventory

    This research plan was developed to describe research needed to support EPAs development of drinking water regulations concerning disinfectants, disinfection by-products (DBPs) and microbial pathogens, focusing on key scientific and technical information needed. ...

  13. Roadmap for Interdisciplinary Research on Drinking Water Disinfection By-Products

    EPA Science Inventory

    Slide presentation on interdisciplinary research on drinking water disinfection by-products which summarized important issues with drinking water disinfection by-products and focused on emerging, unregulated DBPs.

  14. QUENCHING OF CHLORINATION DISINFECTION BY-PRODUCT FORMATION IN DRINKING WATER BY HYDROGEN PEROXIDE. (R825362)

    EPA Science Inventory

    Reactions between chlorine disinfectants, dissolved organic matter, and other chemicals in water form a series of disinfection by-products (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs), that are toxic and subject to increasingly stringent regulations. Th...

  15. 9 CFR 85.13 - Cleaning and disinfecting livestock markets and other facilities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... using one of the disinfectants registered under the Federal Insecticide, Fungicide and Rodenticide Act, as amended (7 U.S.C. 135 et seq.) with herpes virucidal claims. These disinfectants shall be used...

  16. 9 CFR 85.13 - Cleaning and disinfecting livestock markets and other facilities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... using one of the disinfectants registered under the Federal Insecticide, Fungicide and Rodenticide Act, as amended (7 U.S.C. 135 et seq.) with herpes virucidal claims. These disinfectants shall be used...

  17. 9 CFR 85.13 - Cleaning and disinfecting livestock markets and other facilities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... using one of the disinfectants registered under the Federal Insecticide, Fungicide and Rodenticide Act, as amended (7 U.S.C. 135 et seq.) with herpes virucidal claims. These disinfectants shall be used...

  18. 9 CFR 85.13 - Cleaning and disinfecting livestock markets and other facilities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... using one of the disinfectants registered under the Federal Insecticide, Fungicide and Rodenticide Act, as amended (7 U.S.C. 135 et seq.) with herpes virucidal claims. These disinfectants shall be used...

  19. 9 CFR 85.13 - Cleaning and disinfecting livestock markets and other facilities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... using one of the disinfectants registered under the Federal Insecticide, Fungicide and Rodenticide Act, as amended (7 U.S.C. 135 et seq.) with herpes virucidal claims. These disinfectants shall be used...

  20. CHEMICAL AND BIOLOGICAL CHARACTERIZATION OF NEWLY DISCOVERED IODOACID DRINKING WATER DISINFECTION BYPRODUCTS

    EPA Science Inventory

    Iodoacid drinking water disinfection byproducts (DBPs) were recently uncovered in drinking water samples from source water with a high bromide/iodide concentration that was disinfected with chloramines. The purpose of this paper is to report the analytical chemical identification...

  1. DEVELOPMENT OF A RATIONALLY BASED DESIGN PROTOCOL FOR THE ULTRAVIOLET LIGHT DISINFECTION PROCESS

    EPA Science Inventory

    A protocol is demonstrated for the design and evaluation of ultraviolet (UV) disinfection systems based on a mathematical model. The disinfection model incorporates the system's physical dimensions, the residence time distribution of the reactor and dispersion characteristics, th...

  2. 40 CFR 141.708 - Requirements when making a significant change in disinfection practice.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... calculate disinfection benchmarks for Giardia lamblia and viruses as described in § 141.709. Prior to... disinfection benchmark for Giardia lamblia and viruses as described in § 141.709. (2) A description of...

  3. 40 CFR 141.708 - Requirements when making a significant change in disinfection practice.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... calculate disinfection benchmarks for Giardia lamblia and viruses as described in § 141.709. Prior to... disinfection benchmark for Giardia lamblia and viruses as described in § 141.709. (2) A description of...

  4. 40 CFR 141.708 - Requirements when making a significant change in disinfection practice.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... calculate disinfection benchmarks for Giardia lamblia and viruses as described in § 141.709. Prior to... disinfection benchmark for Giardia lamblia and viruses as described in § 141.709. (2) A description of...

  5. NEW DISINFECTION BY-PRODUCT ISSUES: EMERGING DBP'S AND ALTERNATIVE ROUTES OF EXPOSURE

    EPA Science Inventory

    This paper discusses current issues with drinking water disinfection by-products (DBPs), which include emerging (unregulated) DBPs that can be formed at greater levels with alternative disinfectants (as compared to chlorine) and routes of human exposure (which include inhalation ...

  6. Integrated Disinfection By-Products Mixtures Research: Concentration by Reverse Osmosis Membrane Techniques of Disinfection By-Products from Water Disinfected by Chlorination and Ozonation/Postchlorination

    EPA Science Inventory

    To conduct the health-effect studies described in subsequent articles in this series, concentrated aqueous mixtures of disinfection by-products were required for the two water treatment trains described in the preceding article (Miltner et al., 2008). To accomplish this, the fini...

  7. A multi-purpose computing center: FNAL

    SciTech Connect

    Wolbers, Stephen; /Fermilab

    2009-01-01

    The Fermilab Computing Center is described with a special emphasis given to the scientific computing systems and the data storage and archiving systems. The scope and focus of this paper is the Fermilab scientific computing facility. It does not cover, or does not cover very well, related issues such as data Grids, cloud computing and storage, commercial storage, data integrity, authorization, access rates, and novel storage technologies. These are all important considerations in discussing data centers and should be kept in mind when one explores issues related to computing centers and long-term data storage.

  8. Quarkonia as a multi-purpose tool

    SciTech Connect

    Vogt, R

    2010-12-21

    Quarkonia can be a very useful tool for understanding the medium in which they are produced and pass through. However, their usefulness as a tool depends on how well certain aspects of their behavior in cold matter are understood.

  9. Dual-Channel Multi-Purpose Telescope

    NASA Technical Reports Server (NTRS)

    Howard, Joseph M.; Content, David

    2009-01-01

    A dual-channel telescope allows for a wide-field telescope design wit h a good, narrow field channel of fewer surfaces for shorter-wavelen gth or planet-finding applications. The design starts with a Korsch three-mirror-anastigmat (TMA) telescope that meets the mission criter ia for image quality over a wide field of view. The internal image a t the Cassegrain focus is typically blurry due to the aberration bala ncing among the three mirrors. The Cassegrain focus is then re-optim ized on the axis of the system where the narrow field channel instru ment is picked off by bending the primary mirror.

  10. Selection criteria for water disinfection techniques in agricultural practices.

    PubMed

    Haute, Sam van; Sampers, Imca; Jacxsens, Liesbeth; Uyttendaele, Mieke

    2015-01-01

    This paper comprises a selection tool for water disinfection methods for fresh produce pre- and postharvest practices. A variety of water disinfection technologies is available on the market and no single technology is the best choice for all applications. It can be difficult for end users to choose the technology that is best fit for a specific application. Therefore, the different technologies were characterized in order to identify criteria that influence the suitability of a technology for pre- or postharvest applications. Introduced criteria were divided into three principal components: (i) criteria related to the technology and which relate to the disinfection efficiency, (ii) attention points for the management and proper operation, and (iii) necessities in order to sustain the operation with respect to the environment. The selection criteria may help the end user of the water disinfection technology to obtain a systematic insight into all relevant aspects to be considered for preliminary decision making on which technologies should be put to feasibility testing for water disinfection in pre- and postharvest practices of the fresh produce chain. PMID:24279431

  11. Disinfection by-product formation during seawater desalination: A review.

    PubMed

    Kim, Daekyun; Amy, Gary L; Karanfil, Tanju

    2015-09-15

    Due to increased freshwater demand across the globe, seawater desalination has become the technology of choice in augmenting water supplies in many parts of the world. The use of chemical disinfection is necessary in desalination plants for pre-treatment to control both biofouling as well as the post-disinfection of desalinated water. Although chlorine is the most commonly used disinfectant in desalination plants, its reaction with organic matter produces various disinfection by-products (DBPs) (e.g., trihalomethanes [THMs], haloacetic acids [HAAs], and haloacetonitriles [HANs]), and some DBPs are regulated in many countries due to their potential risks to public health. To reduce the formation of chlorinated DBPs, alternative oxidants (disinfectants) such as chloramines, chlorine dioxide, and ozone can be considered, but they also produce other types of DBPs. In addition, due to high levels of bromide and iodide concentrations in seawater, highly cytotoxic and genotoxic DBP species (i.e., brominated and iodinated DBPs) may form in distribution systems, especially when desalinated water is blended with other source waters having higher levels of organic matter. This article reviews the knowledge accumulated in the last few decades on DBP formation during seawater desalination, and summarizes in detail, the occurrence of DBPs in various thermal and membrane plants involving different desalination processes. The review also identifies the current challenges and future research needs for controlling DBP formation in seawater desalination plants and to reduce the potential toxicity of desalinated water. PMID:26099832

  12. UV disinfection for reuse applications in North America.

    PubMed

    Sakamoto, G; Schwartzel, D; Tomowich, D

    2001-01-01

    In an effort to conserve and protect limited water resources, the States of Florida and California have actively promoted wastewater reclamation and have implemented comprehensive regulations covering a range of reuse applications. Florida has a semi-tropical climate with heavy summer rains that are lost due to run off and evaporation. Much of California is arid and suffers periodic droughts, low annual rainfall and depleted ground water supplies. The high population density combined with heavy irrigation demands has depleted ground water supplies resulting in salt-water intrusion. During the past decade, Florida reuse sites have increased dramatically from 118 to 444 plants representing a total flow capacity of 826 MGD. California presently has over 250 plants producing 1 BGD with a projected increase of 160 sites over the next 20 years. To prevent the transmission of waterborne diseases, disinfection of reclaimed water is controlled by stringent regulations. Many states regulate wastewater treatment processes, nutrient removal, final effluent quality and disinfection criteria based upon the specific reuse application. As a rule, the resulting effluents have low turbidity and suspended solids. For such effluents, UV technology can economically achieve the most stringent disinfection targets that are required by the States of California and Florida for restricted and unrestricted reuse. This paper compares UV disinfection for wastewater reuse sites in California and Florida and discusses the effect of effluent quality on UV disinfection. PMID:11436778

  13. Disinfection/sterilization of extracted teeth for dental student use.

    PubMed

    Dominici, J T; Eleazer, P D; Clark, S J; Staat, R H; Scheetz, J P

    2001-11-01

    Extracted human teeth are used in many preclinical courses. While there has been no report of disease transmission with extracted teeth, sterilization of teeth used in the teaching laboratory should be a concern. The purpose of this study was to determine the effectiveness of different sterilization/disinfection methods of extracted human teeth using Bacillus stearothermophilus, a bacteria resistant to heat and frequently used to test sterilizers. In this study, 110 extracted molars with no carious lesions were collected and stored in buffered saline. An endodontic occlusal access preparation was cut into the pulp chamber of each tooth. Pulp tissue in the chamber was removed with a broach. Approximately 1 x 10(5) B. stearothermophilus endospores in culture medium were injected into the pulp chamber, sealed with Cavit G, and then placed in sterile saline for twelve hours. Ten teeth were placed into each of eleven groups. Seven groups were immersed for one week in one of the following solutions: a) sterile saline (control group), b) 5.25% NaOCl, c) 2.6% NaOCl, d) 1% NaOCl, e) 10% buffered formalin, f) 2% gluteraldehyde, g) 0.28% quaternary ammonium. Four additional groups were treated by h) 10% formalin for two days, i) 10% formalin for four days, j) autoclaving at 240 degrees F and 20 psi for twenty minutes, and k) autoclaving at 240 degrees F and twenty psi for forty minutes. Each tooth was then aseptically split and placed in an individual test tube with growth medium. Samples were examined for evidence of growth (turbidity) at forty-eight hours. Only autoclaving for forty minutes at 240 degrees F and 20 psi or soaking in 10 percent formalin for one week were 100 percent effective in preventing growth. A chi-square analysis of the data indicates these two methods were significantly better than all other methods (p<0.001). PMID:11765875

  14. Evaluation of two recommended disinfection methods for cleaning cloths used in food services of southern Brazil

    PubMed Central

    Bartz, Sabrina; Tondo, Eduardo Cesar

    2013-01-01

    In the State of Rio Grande do Sul (RS), Southern Brazil, a good manufacturing practices regulation was published recommending two disinfection methods for cleaning cloths used in food services. The aim of the present study was to evaluate the efficacy of those methods. Cleaning cloths were sampled without prior notice at food services, on common working days. For the analyses, the cloths were divided in two sub-samples, being one of them microbiologically analyzed. The second sub-sample was further divided in two pieces and submitted to hand washing for two minutes. After that, one piece was boiled in water for 15 min and the other one was soaked in a 200 ppm sodium hypochlorite solution for 15 min. Both pieces of cloth were submitted to microbiological analyses. Cleaning cloths presented total aerobic mean counts of 6.9 ± 6.7 log/cm2. All cleaning cloths presented coliform contamination, and 40% demonstrated mean counts of 6.2 ± 5.6 log/cm2. Presumptive S. aureus mean counts of 5.5 ± 4.9 log/cm2 were found. No statistic correlation was observed among the number of meals served daily in the food services and the microbiological contamination levels. After washing and disinfection, microbiological counts were significantly (p < 0.05) reduced by both methods, achieving an approximately 5 log reduction. The reductions achieved by the sodium hypochlorite soaking method and the boiling method were not significantly different. Thus, it was possible to conclude that both recommended methods were suitable to disinfect cleaning cloths used in food services. PMID:24516443

  15. Evaluation of two recommended disinfection methods for cleaning cloths used in food services of southern Brazil.

    PubMed

    Bartz, Sabrina; Tondo, Eduardo Cesar

    2013-01-01

    In the State of Rio Grande do Sul (RS), Southern Brazil, a good manufacturing practices regulation was published recommending two disinfection methods for cleaning cloths used in food services. The aim of the present study was to evaluate the efficacy of those methods. Cleaning cloths were sampled without prior notice at food services, on common working days. For the analyses, the cloths were divided in two sub-samples, being one of them microbiologically analyzed. The second sub-sample was further divided in two pieces and submitted to hand washing for two minutes. After that, one piece was boiled in water for 15 min and the other one was soaked in a 200 ppm sodium hypochlorite solution for 15 min. Both pieces of cloth were submitted to microbiological analyses. Cleaning cloths presented total aerobic mean counts of 6.9 ± 6.7 log/cm(2). All cleaning cloths presented coliform contamination, and 40% demonstrated mean counts of 6.2 ± 5.6 log/cm(2). Presumptive S. aureus mean counts of 5.5 ± 4.9 log/cm(2) were found. No statistic correlation was observed among the number of meals served daily in the food services and the microbiological contamination levels. After washing and disinfection, microbiological counts were significantly (p < 0.05) reduced by both methods, achieving an approximately 5 log reduction. The reductions achieved by the sodium hypochlorite soaking method and the boiling method were not significantly different. Thus, it was possible to conclude that both recommended methods were suitable to disinfect cleaning cloths used in food services. PMID:24516443

  16. Testing the Carcinogenic Potential of Water Disinfectant Byproducts in a Human Colon Mucosal Culture System

    EPA Science Inventory

    Epidemiological studies have linked the consumption of disinfected surface waters to an increased risk of colorectal cancer. Approximately 600 disinfection byproducts (DBPs) have been identified for a number of disinfectants currently in use. An in-depth mechanism-based structure...

  17. USING MEMBRANES TO CONCENTRATE DISINFECTION BYPRODUCTS FOR SUBSEQUENT HEALTH EFFECTS STUDIES

    EPA Science Inventory

    Chemical disinfection of water is a major public health advance that has decreased dramatically water-borne disease. Disinfecting agents react with naturally occurring organic and inorganic matter in water to produce a wide variety of disinfection byproducts (DBPs). Although mo...

  18. MAMMALIAN CELL CYTOTOXICITY AND GENOTOXICITY OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS

    EPA Science Inventory

    The disinfection of drinking water continues to protect the public health against acute disease. Drinking water disinfection by-products (DBPs) are formed by the reaction of a disinfectant with naturally occurring organic matter. Many DBPs are genotoxic and are implicated as huma...

  19. 40 CFR 141.533 - What data must my system collect to calculate a disinfection profile?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... system uses chlorine, the pH of the disinfected water at each residual disinfectant concentration... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced... week on the same calendar day, over 12 consecutive months: (a) The temperature of the disinfected...

  20. Evaluation of disinfectants to prevent mechanical transmission of viruses and a viroid in greenhouse tomato production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to select disinfectant(s) with capability to deactivate infectivity from a broad range of viruses and viroids that are commonly observed in greenhouse tomato production systems, a total of 16 disinfectants were evaluated against Pepino mosaic virus (PepMV), Tomato mosaic virus (ToMV), T...