Physical characteristics of commercial and home-made nasal lavage solutions.

PubMed

Lilic, N; Waldvogel-Thurlow, S; Douglas, R G

2014-01-01

Nasal saline lavage forms a cornerstone of chronic rhinosinusitis management. A number of saline lavage recipes and products are currently available but little is known of their relative physical characteristics. To determine the osmolarity and pH of nasal lavage solutions, both commercial preparations and home-made recipes, and to determine the reproducibility of saline solution preparation. Five home-made recipes and two commercial products were prepared in triplicate and analysed. Eight consecutive clinic patients prepared a commercial product and 11 prepared a home-made recipe, and the osmolarity and pH were measured. The osmolarity of the solutions varied widely, from 140 to 788 mmol/l and the pH varied from 7.88 to 8.50. The commercial and home-made solutions had similar reproducibility when prepared by patients. Some recipes were markedly hypo-osmolar and some were hyper-osmolar. All were slightly alkaline. The home-made recipes had similar physical characteristics and reproducibility to commercial preparations.

Effects of temperature, salinity, light intensity, and pH on the eicosapentaenoic acid production of Pinguiococcus pyrenoidosus

NASA Astrophysics Data System (ADS)

Sang, Min; Wang, Ming; Liu, Jianhui; Zhang, Chengwu; Li, Aifen

2012-06-01

The effects of temperature, light intensity, salinity, and initial pH on the growth and fatty acid composition of Pinguiococcus pyrenoidosus 2078 were studied for eicosapentaenoic acid (EPA) production potential. The fatty acid composition was assayed by gas chromatography-mass spectrometry, which indicated that the main fatty acids were C14:0, C16:0 and EPA. The highest EPA percentage 20.83% of total fatty acids was obtained at 20°C with the temperature being set at 20, 24, and 28°C. Under different salinities and light intensities, the highest percentages of total polyunsaturated fatty acids (PUFAs) and EPA were 17.82% and 31.37% of total fatty acids, respectively, which were achieved at salinity 30 and 100 μmol photon m-2s-1 illumination. The highest percentages of total PUFAs and EPA were 38.75% and 23.13% of total fatty acids, respectively, which were reached at an initial pH of 6 with the test range being from 5.0 to 9.0.

Influence of Soil Solution Salinity on Molybdenum Adsorption by Soils

USDA-ARS?s Scientific Manuscript database

Molybdenum (Mo) adsorption on five arid-zone soils from California was investigated as a function of equilibrium solution Mo concentration (0-30 mg L-1), solution pH (4-8), and electrical conductivity (EC = 0.3 or 8 dS m-1). Molybdenum adsorption decreased with increasing pH. An adsorption maximum...

Capacitive Deionization of High-Salinity Solutions

DOE PAGES

Sharma, Ketki; Gabitto, Jorge; Mayes, Richard T.; ...

2014-12-22

Desalination of high salinity solutions has been studied using a novel experimental technique and a theoretical model. Neutron imaging has been employed to visualize lithium ions in mesoporous carbon materials, which are used as electrodes in capacitive deionization for water desalination. Experiments were conducted with a flow-through capacitive deionization cell designed for neutron imaging and with lithium chloride ( 6LiCl) as the electrolyte. Sequences of neutron images have been obtained at a relatively high concentration of lithium chloride ( 6LiCl) solution to provide information on the transport of ions within the electrodes. A new model that computes the individual ionicmore » concentration profiles inside mesoporous carbon electrodes has been used to simulate the capacitive deionization process. Modifications have also been introduced into the simulation model to calculate results at high electrolyte concentrations. Experimental data and simulation results provide insight into why capacitive deionization is not effective for desalination of high ionic-strength solutions. The combination of experimental information, obtained through neutron imaging, with the theoretical model will help in the design of capacitive deionization devices, which can improve the process for high ionic-strength solutions.« less

Computer model of hydroponics nutrient solution pH control using ammonium.

PubMed

Pitts, M; Stutte, G

1999-01-01

A computer simulation of a hydroponics-based plant growth chamber using ammonium to control pH was constructed to determine the feasibility of such a system. In nitrate-based recirculating hydroponics systems, the pH will increase as plants release hydroxide ions into the nutrient solution to maintain plant charge balance. Ammonium is an attractive alternative to traditional pH controls in an ALSS, but requires careful monitoring and control to avoid overdosing the plants with ammonium. The primary advantage of using NH4+ for pH control is that it exploits the existing plant nutrient uptake charge balance mechanisms to maintain solution pH. The simulation models growth, nitrogen uptake, and pH of a l-m2 stand of wheat. Simulation results indicated that ammonium-based control of nutrient solution pH is feasible using a proportional integral controller. Use of a 1 mmol/L buffer (Ka = 1.6 x 10(-6)) in the nutrient solution is required.

Salinity and Alkaline pH in Irrigation Water Affect Marigold Plants: II. Mineral Ion Relations

USDA-ARS?s Scientific Manuscript database

Scarcity of water of good quality for landscape irrigation is of outmost importance in arid and semiarid regions due to the competition with urban population. This is forcing the use of degraded waters with high levels of salinity and high pH, which may affect plant establishment and growth. The o...

Common toads (Bufo arenarum) learn to anticipate and avoid hypertonic saline solutions.

PubMed

Daneri, M Florencia; Papini, Mauricio R; Muzio, Rubén N

2007-11-01

Toads (Bufo arenarum) were exposed to pairings between immersion in a neutral saline solution (i.e., one that caused no significant variation in fluid balance), followed by immersion in a highly hypertonic saline solution (i.e., one that caused water loss). In Experiment 1, solutions were presented in a Pavlovian conditioning arrangement. A group receiving a single neutral-highly hypertonic pairing per day exhibited a greater conditioned increase in heart rate than groups receiving either the same solutions in an explicitly unpaired fashion, or just the neutral solution. Paired toads also showed a greater ability to compensate for water loss across trials than that of the explicitly unpaired group. Using the same reinforcers and a similar apparatus, Experiment 2 demonstrated that toads learn a one-way avoidance response motivated by immersion in the highly hypertonic solution. Cardiac and avoidance conditioning are elements of an adaptive system for confronting aversive situations involving loss of water balance. Copyright 2007 APA.

Impact of temperature, pH, and salinity changes on the physico-chemical properties of model naphthenic acids.

PubMed

Celsie, Alena; Parnis, J Mark; Mackay, Donald

2016-03-01

The effects of temperature, pH, and salinity change on naphthenic acids (NAs) present in oil-sands process wastewater were modeled for 55 representative NAs. COSMO-RS was used to estimate octanol-water (KOW) and octanol-air (KOA) partition ratios and Henry's law constants (H). Validation with experimental carboxylic acid data yielded log KOW and log H RMS errors of 0.45 and 0.55 respectively. Calculations of log KOW, (or log D, for pH-dependence), log KOA and log H (or log HD, for pH-dependence) were made for model NAs between -20 °C and 40 °C, pH between 0 and 14, and salinity between 0 and 3 g NaCl L(-1). Temperature increase by 60 °C resulted in 3-5 log unit increase in H and a similar magnitude decrease in KOA. pH increase above the NA pKa resulted in a dramatic decrease in both log D and log HD. Salinity increase over the 0-3 g NaCl L(-1) range resulted in a 0.3 log unit increase on average for KOW and H values. Log KOW values of the sodium salt and anion of the conjugate base were also estimated to examine their potential for contribution to the overall partitioning of NAs. Sodium salts and anions of naphthenic acids are predicted to have on average 4 log units and 6 log units lower log KOW values, respectively, with respect to the corresponding neutral NA. Partitioning properties are profoundly influenced by the by the relative prevailing pH and the substance's pKa at the relevant temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

The importance of pH and sand substrate in the revegetation of saline non-waterlogged peat fields.

PubMed

Montemayor, Marilou B; Price, Jonathan; Rochefort, Line

2015-11-01

A partially peat-extracted coastal bog contaminated by seawater was barren and required revegetation as a wetland. Peat fields were rectangular in shape, cambered in cross-section profile, and separated by drainage ditches. Common to all peat fields were symmetrical patterns in micro-topography with slopes between differences in elevation. Saline non-waterlogged slopes of ∼5% occurred as a symmetrical pair on each side of the crest of the cambered profile, at one end of each peat field. Three rows were laid across this slope (Top, Middle, and Bottom rows) and transplanted with naturally-growing plant species with their sand substrate, in three experiments, and grown for a year. In the Spartina pectinata experiment, bare root stem sections were also planted. Another experiment was conducted to determine changes in the characteristics of a volume of sand when incubated in saline peat fields. We found the salinity of peat increased with moisture downslope, and pH decreased with increase in salinity. S. pectinata grew best when planted with its sand substrate compared with bare root stem section, and when planted in Bottom rows. Juncus balticus had excellent growth in all rows. Unexpectedly, Festuca rubra that was inconspicuous beneath the J. balticus canopy in the natural donor site grew densely within the J. balticus sods. Agrostis stolonifera grew well but seemed to show intolerance to the surrounding acidic peat by curling up its stolons. The pH of the incubated sand volume was much higher than the surrounding peat. These studies suggest that recognition of plant niches and pH manipulation are important in the revegetation of disturbed Sphagnum peatlands that are found abundantly in the northern hemisphere. Results are also relevant to the reclamation of other disturbed lands. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electrochemical control of pH in a hydroponic nutrient solution

NASA Technical Reports Server (NTRS)

Schwartzkopf, S. H.

1986-01-01

The electrochemical pH control system described was found to provide a feasible alternative method of controlling nutrient solution pH for CELSS applications. The plants grown in nutrient solution in which the pH was controlled electrochemically showed no adverse effects. Further research into the design of a larger capacity electrode bridge for better control is indicated by the results of this experiment, and is currently under way.

Effects of solutions treated with oxygen radicals in neutral pH region on inactivation of microorganism

NASA Astrophysics Data System (ADS)

Kobayashi, Tsuyoshi; Hashizume, Hiroshi; Ohta, Takayuki; Ishikawa, Kenji; Hori, Masaru; Ito, Masafumi

2015-09-01

The inactivation of microorganisms using nonequilbrium atmospheric pressure plasmas has been attracted much attention due to the low temperature processing and high speed treatment. In this study, we have inactivated E. coli suspended in solutions with neutral pH using an atmospheric-pressure oxygen radical source which can selectively supply electrically neutral oxygen radicals. E. coli cells were suspended with deionized distilled water (DDW) (pH = 6.8) or phosphate buffered saline (PBS) (pH = 7.4) or Citrate-Na buffer (pH = 6.5). The treated samples were diluted and spread on nutrient agar (Nutrient Broth). They were cultured at 37° C. The inactivation effects of oxygen radicals on those cells in solutions were evaluated by colony-counting method. O2 diluted by Ar gas were employed as a working gas for the radical source. The total gas flow rate and the gas mixture ratio of O2/(Ar + O2) were set at 5 slm and 0.6%, respectively. The distance between the radical exit and the suspension surface were set at 10 mm. As a result, the D values for DDW(pH = 6.8), PBS(pH = 7.4) and Citrate-Na buffer(pH = 6.5) were estimated to be 1.4 min, 0.9 min and 16.8 min respectively. The inactivation rates in DDW, PBS were significantly different from that in Citrate-Na buffer. This work was partly supported by JSPS KAKENHI Grant Number 26286072 and project for promoting Research Center in Meijo University.

Photobleaching of chromophoric dissolved organic matter (CDOM) in the Yangtze River estuary: kinetics and effects of temperature, pH, and salinity.

PubMed

Song, Guisheng; Li, Yijie; Hu, Suzheng; Li, Guiju; Zhao, Ruihua; Sun, Xin; Xie, Huixiang

2017-06-21

The kinetics and temperature-, pH- and salinity-dependences of photobleaching of chromophoric dissolved organic matter (CDOM) in the Yangtze River estuary (YRE) were evaluated using laboratory solar-simulated irradiation and compared to those of Suwannee River humic substances (SRHSs). Nearly all CDOM in water at the head of the estuary (headwater herein) was photobleachable in both summer and winter, while significant fractions of CDOM (13-29%) were resistant to photobleaching in saltier waters. The photobleaching rate constant in the headwater was 25% higher in summer than that in winter. The absorbed photon-based photobleaching efficiency (PE) increased with temperature following the linear Arrhenius equation. For a 20 °C increase in temperature, PE increased by ∼45% in the headwater and by 70-81% in the saltier waters. PE for YRE samples exhibited minima at pH from 6 to 7 and increased with both lower and higher pH values, contrasting the consistent increase in PE with pH shown by SRHSs. No consistent effect of salinity on PE was observed for both SRHSs and YRE samples. Photobleaching increased the spectral slope coefficient between 275 nm and 295 nm in summer, consistent with the behavior of SRHSs, but decreased it in winter, implying a difference in the molecular composition of chromophores between the two seasons. Temperature, salinity, and pH modified the photoalteration of the spectral shape but their effects varied spatially and seasonally. This study demonstrates that CDOM quality, temperature, and pH should be incorporated into models involving quantification of photobleaching.

Intravenous hypertonic saline solution (7.5%) and oral electrolytes to treat of calves with noninfectious diarrhea and metabolic acidosis.

PubMed

Leal, M L R; Fialho, S S; Cyrillo, F C; Bertagnon, H G; Ortolani, E L; Benesi, F J

2012-01-01

The aim of this study was to compare the efficacy of treating osmotic diarrhea and dehydration in calves with hypertonic saline solution (HSS) IV, isotonic electrolyte solution (IES) PO, and a combination of these 2 solutions (HSS + IES). Eighteen male calves 8-30 days of age were used to evaluate the efficacy of 3 methods of fluid therapy after induction of osmotic diarrhea and dehydration. The diarrhea and dehydration were induced by administration of saccharose, spironolactone, and hydrochlorothiazide for 48 hours. The animals were randomly divided into 3 experimental groups: Group 1: 7.2% hypertonic saline solution-HSS (5 mL/kg IV); Group 2: oral isotonic electrolyte solution IES (60 mL/kg PO); or Group 3: HSS+IES. Clinical signs and laboratory finding observed 48 hours post-induction (Time 0) included diarrhea, dehydration, lethargy, and metabolic acidosis. Calves treated with HSS + IES experienced decreases in hematocrit, total protein concentration, albumin concentration, urea nitrogen concentration, and plasma volume as well as increases in blood pH, blood bicarbonate concentration, and central venous pressure between 1 and 3 hours post-treatment. These findings also were observed in animals treated with IES, however, at a slower rate than in the HSS + IES-treated animals. Animals treated with HSS continued to display signs of dehydration, lethargy, and metabolic acidosis 24 hours post-treatment. Treatment with a combination of HSS and IES produced rapid and sustainable correction of hypovolemia and metabolic acidosis in calves with noninfections diarrhea and dehydration. Copyright © 2012 by the American College of Veterinary Internal Medicine.

Influence of pH, competing ions, and salinity on the sorption of strontium and cobalt onto biogenic hydroxyapatite

PubMed Central

Handley-Sidhu, Stephanie; Mullan, Thomas K.; Grail, Quentin; Albadarneh, Malek; Ohnuki, Toshihiko; Macaskie, Lynne E.

2016-01-01

Anthropogenic radionuclides contaminate a range of environments as a result of nuclear activities, for example, leakage from waste storage tanks/ponds (e.g. Hanford, USA or Sellafield sites, UK) or as a result of large scale nuclear accidents (e.g. Chernobyl, Ukraine or Fukushima, Japan). One of the most widely applied remediation techniques for contaminated waters is the use of sorbent materials (e.g. zeolites and apatites). However, a key problem at nuclear contaminated sites is the remediation of radionuclides from complex chemical environments. In this study, biogenic hydroxyapatite (BHAP) produced by Serratia sp. bacteria was investigated for its potential to remediate surrogate radionuclides (Sr2+ and Co2+) from environmentally relevant waters by varying pH, salinity and the type and concentration of cations present. The sorption capacity of the BHAP for both Sr2+ and Co2+ was higher than for a synthetically produced hydroxyapatite (HAP) in the solutions tested. BHAP also compared favorably against a natural zeolite (as used in industrial decontamination) for Sr2+ and Co2+ uptake from saline waters. Results confirm that hydroxyapatite minerals of high surface area and amorphous calcium phosphate content, typical for biogenic sources, are suitable restoration or reactive barrier materials for the remediation of complex contaminated environments or wastewaters. PMID:26988070

Influence of pH, competing ions, and salinity on the sorption of strontium and cobalt onto biogenic hydroxyapatite

NASA Astrophysics Data System (ADS)

Handley-Sidhu, Stephanie; Mullan, Thomas K.; Grail, Quentin; Albadarneh, Malek; Ohnuki, Toshihiko; Macaskie, Lynne E.

2016-03-01

Anthropogenic radionuclides contaminate a range of environments as a result of nuclear activities, for example, leakage from waste storage tanks/ponds (e.g. Hanford, USA or Sellafield sites, UK) or as a result of large scale nuclear accidents (e.g. Chernobyl, Ukraine or Fukushima, Japan). One of the most widely applied remediation techniques for contaminated waters is the use of sorbent materials (e.g. zeolites and apatites). However, a key problem at nuclear contaminated sites is the remediation of radionuclides from complex chemical environments. In this study, biogenic hydroxyapatite (BHAP) produced by Serratia sp. bacteria was investigated for its potential to remediate surrogate radionuclides (Sr2+ and Co2+) from environmentally relevant waters by varying pH, salinity and the type and concentration of cations present. The sorption capacity of the BHAP for both Sr2+ and Co2+ was higher than for a synthetically produced hydroxyapatite (HAP) in the solutions tested. BHAP also compared favorably against a natural zeolite (as used in industrial decontamination) for Sr2+ and Co2+ uptake from saline waters. Results confirm that hydroxyapatite minerals of high surface area and amorphous calcium phosphate content, typical for biogenic sources, are suitable restoration or reactive barrier materials for the remediation of complex contaminated environments or wastewaters.

Sperm characteristics of wild and captive lebranche mullet Mugil liza (Valenciennes, 1836), subjected to sperm activation in different pH and salinity conditions.

PubMed

Magnotti, C; Figueroa, E; Farias, J G; Merino, O; Valdebenito, I; Oliveira, R P S; Cerqueira, V

2018-05-01

In this article we describe basic aspects of the sperm biology of lebranche mullet (Mugil liza) in the wild and in captivity, in particular assessing the effects of salinity (0, 10, 20, 30, 35, 40, 50 and 60 g L -1 ) and pH (6, 7, 8, 9 and 10) on sperm motility. Our results indicate that the highest percentage of motility was recorded with salinity 34.6 g L -1 (95 ± 10%) and the longest motility time was obtained with a salinity of 34.8 g L -1 (189 ± 15 s). Variations in the salinity between 30 and 35 g L -1 did not produce any significant alterations in sperm motility; however salinities of 20 and 50 g L -1 produced a significant loss of sperm motility. The highest percentage of motility was obtained at pH 8.5 (93 ± 12%), and the longest motility period at pH 8.7 (218 ± 13 s), while pH lower than or equal to 7 and equal to 10 both produced a significant loss in sperm motility. A positive correlation was found between pH/salinity and the motility percentage (R 2  = 0.94 and R 2  = 0.97) and motility time (R 2  = 0.86 and R 2  = 0.98). In seminal and morphometric parameters, statistically significant differences were observed in semen volume, sperm density, plasma membrane integrity and sperm morphometry between the groups studied, showing that the characteristics of the fish have a direct influence on sperm quality. The information generated in this research will be useful for developing biotechnology tools for the effective management of Mugil liza gametes. Copyright © 2018 Elsevier B.V. All rights reserved.

Etched FBG coated with polyimide for simultaneous detection the salinity and temperature

NASA Astrophysics Data System (ADS)

Luo, Dong; Ma, Jianxun; Ibrahim, Zainah; Ismail, Zubaidah

2017-06-01

In marine environment, concrete structures can corrode because of the PH alkalinity of concrete paste; and the salinity PH is heavily related with the concentration of salt in aqueous solutions. In this study, an optical fiber salinity sensor is proposed on the basis of an etched FBG (EFBG) coated with a layer of polyimide. Chemical etching is employed to reduce the diameter of FBG and to excite Cladding Mode Resonance Wavelengths (CMRWs). CMRW and Fundamental Mode Resonance Wavelength (FMRW) can be used to measure the Refractive index (RI) and temperature of salinity. The proposed sensor is then characterized with a matrix equation. Experimental results show that FMRW and 5th CMRW have the detection sensitivities of 15.407 and 125.92 nm/RIU for RI and 0.0312 and 0.0435 nm/°C for temperature, respectively. The proposed sensor can measure salinity and temperature simultaneously.

Evolution of Spatial pH Distribution in Aqueous Solution induced by Atmospheric Pressure Plasma

NASA Astrophysics Data System (ADS)

Takahashi, Shigenori; Mano, Kakeru; Hayashi, Yui; Takada, Noriharu; Kanda, Hideki; Goto, Motonobu

2016-09-01

Discharge plasma at gas-liquid interface produces some active species, and then they affect chemical reactions in aqueous solution, where pH of aqueous solution is changed due to redox species. The pH change of aqueous solution is an important factor for chemical reactions. However, spatial pH distribution in a reactor during the discharge has not been clarified yet. Thus, this work focused on spatial pH distribution of aqueous solution when pulsed discharge plasma was generated from a copper electrode in gas phase to aqueous solution in a reactor. Experiments were conducted using positive unipolar pulsed power. The unipolar pulsed voltage at +8.0 kV was applied to the copper electrode and the bottom of the reactor was grounded. The size of the reactor was 80 mm wide, 10 mm deep, and 40 mm high. The electrode was set at distance of 2 mm from the solution surface. Anthocyanins were contained in the aqueous solution as a pH indicator. The change pH solution spread horizontally, and low pH region of 10 mm in depth was formed. After discharge for 10 minutes, the low pH region was diffused toward the bottom of the reactor. After discharge for 60 minutes, the pH of the whole solution decreased.

Cryoelectrolysis-electrolytic processes in a frozen physiological saline medium.

PubMed

Lugnani, Franco; Macchioro, Matteo; Rubinsky, Boris

2017-01-01

Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Electrolysis can occur in a frozen domain at high

Evaluating Battery-like Reactions to Harvest Energy from Salinity Differences using Ammonium Bicarbonate Salt Solutions.

PubMed

Kim, Taeyoung; Rahimi, Mohammad; Logan, Bruce E; Gorski, Christopher A

2016-05-10

Mixing entropy batteries (MEBs) are a new approach to generate electricity from salinity differences between two aqueous solutions. To date, MEBs have only been prepared from solutions containing chloride salts, owing to their relevance in natural salinity gradients created from seawater and freshwater. We hypothesized that MEBs could capture energy using ammonium bicarbonate (AmB), a thermolytic salt that can be used to convert waste heat into salinity gradients. We examined six battery electrode materials. Several of the electrodes were unstable in AmB solutions or failed to produce expected voltages. Of the electrode materials tested, a cell containing a manganese oxide electrode and a metallic lead electrode produced the highest power density (6.3 mW m(-2) ). However, this power density is still low relative to previously reported NaCl-based MEBs and heat recovery systems. This proof-of-concept study demonstrated that MEBs could indeed be used to generate electricity from AmB salinity gradients. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of salinity, pH and temperature on the re-establishment of bioluminescence and copper or SDS toxicity in the marine dinoflagellate Pyrocystis lunula using bioluminescence as an endpoint

USGS Publications Warehouse

Craig, J.M.; Klerks, P.L.; Heimann, K.; Waits, J.L.

2003-01-01

Pyrocystis lunula is a unicellular, marine, photoautotrophic, bioluminescent dinoflagellate. This organism is used in the Lumitox ?? bioassay with inhibition of bioluminescence re-establishment as the endpoint. Experiments determined if acute changes in pH, salinity, or temperature had an effect on the organisms' ability to re-establish bioluminescence, or on the bioassay's potential to detect sodium dodecyl sulfate (SDS) and copper toxicity. The re-establishment of bioluminescence itself was not very sensitive to changes in pH within the pH 6-10 range, though reducing pH from 8 to levels below 6 decreased this capacity. Increasing the pH had little effect on Cu or SDS toxicity, but decreasing the pH below 7 virtually eliminated the toxicity of either compound in the bioassay. Lowering the salinity from 33 to 27??? or less resulted in a substantial decrease in re-establishment of bioluminescence, while increasing the salinity to 43 or 48 ??? resulted in a small decline. Salinity had little influence on the bioassay's quantification of Cu toxicity, while the data showed a weak negative relationship between SDS toxicity and salinity. Re-establishment of bioluminescence showed a direct dependence on temperature, but only at 10??C did temperature have an obvious effect on the toxicity of Cu in this bioassay. ?? 2003 Elsevier Science Ltd. All rights reserved.

Revisiting analytical solutions for steady interface flow in subsea aquifers: Aquitard salinity effects

NASA Astrophysics Data System (ADS)

Werner, Adrian D.; Robinson, Neville I.

2018-06-01

Existing analytical solutions for the distribution of fresh groundwater in subsea aquifers presume that the overlying offshore aquitard, represented implicitly, contains seawater. Here, we consider the case where offshore fresh groundwater is the result of freshwater discharge from onshore aquifers, and neglect paleo-freshwater sources. A recent numerical modeling investigation, involving explicit simulation of the offshore aquitard, demonstrates that offshore aquitards more likely contain freshwater in areas of upward freshwater leakage to the sea. We integrate this finding into the existing analytical solutions by providing an alternative formulation for steady interface flow in subsea aquifers, whereby the salinity in the offshore aquitard can be chosen. The new solution, taking the aquitard salinity as that of freshwater, provides a closer match to numerical modeling results in which the aquitard is represented explicitly.

The application of crystal soaking technique to study the effect of zinc and cresol on insulinotropin crystals grown from a saline solution.

PubMed

Kim, Y; Haren, A M

1995-11-01

The purpose of this study is to investigate the effect of zinc and cresol on the structure of insulinotropin crystals. Insulinotropin crystals grown from a saline solution were treated with zinc and/or m-cresol using a crystal soaking technique. The effects of these additives on the crystal structure were investigated with powder X-ray diffraction, photomicrography, and differential scanning calorimetry. The molecular interaction between insulinotropin and m-trifluorocresol in solution was also studied by 19F NMR: The data suggest that the original crystals grown from a saline solution have relatively weak lattice forces. After the addition of m-cresol to the suspension of the insulinotropin crystals, the crystals were immediately rendered amorphous. The m-cresol molecules which diffused into the crystals through solvent channels may have disturbed the lattice interactions that maintain the integrity of the crystal. In contrast, the zinc added to the suspension stabilized the crystal lattice so that the subsequent addition of m-cresol did not alter the integrity of the crystals. A marked increase in melting point (206 degrees versus 184 degrees) and heat of fusion (24.6 J/g versus 1.4 J/g) of the crystals was observed after the treatment with zinc. The solubility of the zinc treated crystals in a pH 7.1 phosphate buffered saline was 1/20 of that of the original crystals. When the insulinotropin crystals were treated with the additives using a crystal soaking method, the crystals underwent structural changes. Zinc stabilized the crystal lattice, and reduced the solubility of the peptide.

Phosphorus sorption capacity of biochars varies with biochar type and salinity level.

PubMed

Dugdug, Abdelhafid Ahmed; Chang, Scott X; Ok, Yong Sik; Rajapaksha, Anushka Upamali; Anyia, Anthony

2018-02-10

Biochar is recognized as an effective material for recovering excess nutrients, including phosphorus (P), from aqueous solutions. Practically, that benefits the environment through reducing P losses from biochar-amended soils; however, how salinity influences P sorption by biochar is poorly understood and there has been no direct comparison on P sorption capacity between biochars derived from different feedstock types under non-saline and saline conditions. In this study, biochars derived from wheat straw, hardwood, and willow wood were used to compare P sorption at three levels of electrical conductivity (EC) (0, 4, and 8 dS m -1 ) to represent a wide range of salinity conditions. Phosphorus sorption by wheat straw and hardwood biochars increased as aqueous solution P concentration increased, with willow wood biochar exhibiting an opposite trend for P sorption. However, the pattern for P sorption became the same as the other biochars after the willow wood biochar was de-ashed with 1 M HCl and 0.05 M HF. Willow wood biochar had the highest P sorption (1.93 mg g -1 ) followed by hardwood (1.20 mg g -1 ) and wheat straw biochars (1.06 mg g -1 ) in a 25 mg L -1 P solution. Although the pH in the equilibrium solution was higher with willow wood biochar (~ 9.5) than with the other two biochars (~ 6.5), solution pH had no or minor effects on P sorption by willow wood biochar. The high sorption rate of P by willow wood biochar could be attributed to the higher concentrations of salt and other elements (i.e., Ca and Mg) in the biochar in comparison to that in wheat straw and hardwood biochars; the EC values were 2.27, 0.53, and 0.27 dS m -1 for willow wood, wheat straw, and hardwood biochars, respectively. A portion of P desorbed from the willow wood biochar; and that desorption increased with the decreasing P concentration in the aqueous solution. Salinity in the aqueous solution influenced P sorption by hardwood and willow wood but not by wheat straw

Controls on the pH of hyper-saline lakes - A lesson from the Dead Sea

NASA Astrophysics Data System (ADS)

Golan, Rotem; Gavrieli, Ittai; Ganor, Jiwchar; Lazar, Boaz

2016-01-01

The pH of aqueous environments is determined by the dominant buffer systems of the water, defined operationally as total alkalinity (TA). The major buffer systems in the modern ocean are carbonic and boric acids of which the species bicarbonate, carbonate and borate make up about 77%, 19% and 4% of the TA, respectively. During the course of seawater evaporation (e.g. lagoons) the residual brine loses considerable portion of the dissolved inorganic carbon (DIC) and carbonate alkalinity (CA) already at the early stages of evaporation. DIC and CA decrease due to massive precipitation of CaCO3, while total boron (TB) increases conservatively, turning borate to the dominant alkalinity species in marine derived brines. In the present work we assess the apparent dissociation constant value of boric acid (KB‧) in saline and hypersaline waters, using the Dead Sea (DS) as a case study. We explain the DS low pH (∼6.3) and the effect of the boric and carbonic acid pK‧-s on the behavior of the brine's buffer system, including the pH increase that results from brine dilution. The KB‧ in DS was estimated from TB, TA, DIC and pH data measured in this study and early empirical data on artificial DS brines containing just carbonic acid. The KB‧ value was corroborated by Pitzer ion interaction model calculations using PHREEQC thermodynamic code applied to the chemical composition of the DS. Our results show that KB‧ increases considerably with the brine's ionic strength, reaching in the DS to a factor of 100 higher than in ;mean; seawater. Based on theoretical calculations and analyses of other natural brines it is suggested that brines' composition is a major factor in determining the KB‧ value and in turn the pH of such brines. We show that the higher the proportion of divalent cations in the brine the higher the dissociation constants of the weak acids (presumably due to formation of complexes). The low pH of the Dead Sea is accordingly explained by its extremely

Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

PubMed Central

Lugnani, Franco; Macchioro, Matteo

2017-01-01

Background Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. Method To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Results Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. Discussion The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Conclusion

Do catheter washouts extend patency time in long-term indwelling urethral catheters? A randomized controlled trial of acidic washout solution, normal saline washout, or standard care.

PubMed

Moore, Katherine N; Hunter, Kathleen F; McGinnis, Rosemary; Bacsu, Chasta; Fader, Mandy; Gray, Mikel; Getliffe, Kathy; Chobanuk, Janice; Puttagunta, Lakshmi; Voaklander, Donald C

2009-01-01

Blockage of long-term indwelling catheters with mineral deposit is an ongoing management issue, but evidence on optimal management is lacking. Our purpose was to examine whether catheter washouts prevent or reduce catheter blockage. A multisite randomized controlled trial. Adults with long-term indwelling catheters that required changing every 3 weeks or less, living in the community, and requiring supportive or continuing care were recruited. Participants were randomly assigned to 1 of 3 groups: control (usual care, no washout), saline washout, or commercially available acidic washout solution (Contisol Maelor Pharmaceuticals Ltd, Wrexham, UK). At baseline visit, the catheter was changed and participants were followed weekly for 8 weeks, with checks for catheter patency and urine pH. Participants randomized to saline or commercial solution had a weekly washout with the appropriate solution. Endpoints were 8 weeks (completion data), 3 or more catheter changes in the 8-week period, or symptomatic urinary tract infection (UTI) requiring antibiotics. The study hypothesis was that catheter life would be extended by 25% in the commercial solution group. It was not possible to blind participants or research nurses to washout versus no intervention, but participants in the saline and washout solution groups were blinded to solution type. One hundred twelve potential participants were screened; 73 were enrolled, randomized, and included in the final analysis. Of these, 53 completed the full 8 weeks of data collection; 16 terminated early because of 3 catheter changes or self-reported 'UTI'. Other reasons for termination were hematuria, latex sensitivity, deceased/severe illness, or personal choice. Analysis of variance was used to analyze mean differences on demographic variables and mean number of weeks in study. Kaplan-Meier survival curve analysis showed no statistical difference between the groups in time to first catheter change. At this time, the evidence is

An Electrochemistry Study of Cryoelectrolysis in Frozen Physiological Saline.

PubMed

Manuel, Thomas J; Munnangi, Pujita; Rubinsky, Boris

2017-07-01

Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the processes of electrolysis and solid/liquid phase transformation (freezing). This study investigated this new technique by measuring the pH front propagation and the changes in resistance in a tissue simulant made of physiological saline gel with a pH dye as a function of the sample temperature in the high subzero range above the eutectic. Results demonstrated that effective electrolysis can occur in a high subzero freezing milieu and that the propagation of the pH front is only weakly dependent on temperature. These observations are consistent with a mechanism involving ionic movement through the concentrated saline solution channels between ice crystals at subfreezing temperatures above the eutectic. Moreover, results suggest that Joule heating in these microchannels may cause local microscopic melting, the observed weak dependence of pH front propagation on temperature, and the large changes in resistance with time. A final insight provided by the results is that the pH front propagation from the anode is more rapid than from the cathode, a feature indicative of the electro-osmotic flow from the cathode to the anode. The findings in this paper may be critical for designing future cryoelectrolytic ablation surgery protocols.

Urinary composition predicts diuretic efficiency of hypertonic saline solution with furosemide therapy and heart failure prognosis.

PubMed

Ando, Tomotaka; Okuhara, Yoshitaka; Orihara, Yoshiyuki; Nishimura, Koichi; Yamamoto, Kyoko; Masuyama, Tohru; Hirotani, Shinichi

2018-03-19

Recently, we and other group have reported that furosemide administration along with hypertonic saline solution enhanced diuretic efficiency of furosemide. However, little is known about factors which associated with high diuretic efficiency by hypertonic saline solution with furosemide therapy. To identify predictors of diuretic efficiency in the hypertonic saline solution with furosemide therapy, we recruited 30 consecutive hospitalized heart failure (HF) patients with volume overload (77 ± 10 years, systolic blood pressure > 90 mmHg, and estimated glomerular filtration rate > 15 ml/min/1.73 m 2 ). Hypertonic saline with furosemide solution, consisting of 500 ml of 1.7% hypertonic saline solution with 40 mg of furosemide, was administered continuously over 24 h. The patients were divided into two groups on the basis of 24-h urine volume (UV) after initiation of diuretic treatment ≥ 2000 ml (high urine volume: HUV) and < 2000 ml (low urine volume: LUV). The basal clinical characteristics of both groups were analyzed and the predictors of HUV after receiving the treatment were identified. There were not significant differences between two groups in baseline clinical characteristics and medication. Univariate logistic analysis revealed that blood urea nitrogen/creatinine ratio, urine urea nitrogen/creatinine ratio (UUN/UCre), fractional excretion of sodium, and tricuspid annular plane systolic excursion positively associated with HUV. Multivariate logistic regression analysis revealed that UUN/UCre at baseline was independently associated with HUV, and UUN/UCre best predicts HUV by the therapy with a cut-off value of 6.16 g/dl/g Cre (AUC 0.910, 95% CI 0.696-0.999, sensitivity 80%, specificity 87%). The Kaplan-Meier curves revealed significant difference for HF rehospitalization and death rate at 180 days between patients with UUN/UCre ≥ 6.16 g/dl/g Cre and those with UUN/UCre < 6.16 g/dl/g Cre (log-rank P = 0

Metrological challenges for measurements of key climatological observables: Oceanic salinity and pH, and atmospheric humidity. Part 1: Overview.

PubMed

Feistel, R; Wielgosz, R; Bell, S A; Camões, M F; Cooper, J R; Dexter, P; Dickson, A G; Fisicaro, P; Harvey, A H; Heinonen, M; Hellmuth, O; Kretzschmar, H-J; Lovell-Smith, J W; McDougall, T J; Pawlowicz, R; Ridout, P; Seitz, S; Spitzer, P; Stoica, D; Wolf, H

2016-02-01

Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth's radiation balance, atmospheric water vapour is the strongest "greenhouse" gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. On climatic time scales, melting ice caps and regional deviations of the hydrological cycle result in changes of seawater salinity, which in turn may modify the global circulation of the oceans and their ability to store heat and to buffer anthropogenically produced carbon dioxide. In this paper, together with three companion articles, we examine the climatologically relevant quantities ocean salinity, seawater pH and atmospheric relative humidity, noting fundamental deficiencies in the definitions of those key observables, and their lack of secure foundation on the International System of Units, the SI. The metrological histories of those three quantities are reviewed, problems with their current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures, BIPM, in cooperation with the International Association for the Properties of Water and Steam, IAPWS, along with other international organisations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems in climatology.

Metrological challenges for measurements of key climatological observables: oceanic salinity and pH, and atmospheric humidity. Part 1: overview

NASA Astrophysics Data System (ADS)

Feistel, R.; Wielgosz, R.; Bell, S. A.; Camões, M. F.; Cooper, J. R.; Dexter, P.; Dickson, A. G.; Fisicaro, P.; Harvey, A. H.; Heinonen, M.; Hellmuth, O.; Kretzschmar, H.-J.; Lovell-Smith, J. W.; McDougall, T. J.; Pawlowicz, R.; Ridout, P.; Seitz, S.; Spitzer, P.; Stoica, D.; Wolf, H.

2016-02-01

Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth’s radiation balance, atmospheric water vapour is the strongest ‘greenhouse’ gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. On climatic time scales, melting ice caps and regional deviations of the hydrological cycle result in changes of seawater salinity, which in turn may modify the global circulation of the oceans and their ability to store heat and to buffer anthropogenically produced carbon dioxide. In this paper, together with three companion articles, we examine the climatologically relevant quantities ocean salinity, seawater pH and atmospheric relative humidity, noting fundamental deficiencies in the definitions of those key observables, and their lack of secure foundation on the International System of Units, the SI. The metrological histories of those three quantities are reviewed, problems with their current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures, BIPM, in cooperation with the International Association for the Properties of Water and Steam, IAPWS, along with other international organizations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems in climatology.

Combined effects of seawater acidification and salinity changes in Ruditapes philippinarum.

PubMed

Velez, Catia; Figueira, Etelvina; Soares, Amadeu M V M; Freitas, Rosa

2016-07-01

Due to human activities, predictions for the coming years indicate increasing frequency and intensity of extreme weather events (rainy and drought periods) and pollution levels, leading to salinity shifts and ocean acidification. Therefore, several authors have assessed the effects of seawater salinity shifts and pH decrease on marine bivalves, but most of these studies evaluated the impacts of both factors independently. Since pH and salinity may act together in the environment, and their impacts may differ from their effects when acting alone, there is an urgent need to increase our knowledge when these environmental changes act in combination. Thus, the present study assessed the effects of seawater acidification and salinity changes, both acting alone and in combination, on the physiological (condition index, Na and K concentrations) and biochemical (oxidative stress related biomarkers) performance of Ruditapes philippinarum. For that, specimens of R. philippinarum were exposed for 28days to the combination of different pH levels (7.8 and 7.3) and salinities (14, 28 and 35). The results obtained showed that under control pH (7.8) and low salinity (14) the physiological status and biochemical performance of clams was negatively affected, revealing oxidative stress. However, under the same pH and at salinities 28 and 35 clams were able to maintain/regulate their physiological status and biochemical performance. Moreover, our findings showed that clams under low pH (7.3) and different salinities were able to maintain their physiological status and biochemical performance, suggesting that the low pH tested may mask the negative effects of salinity. Our results further demonstrated that, in general, at each salinity, similar physiological and biochemical responses were found in clams under both tested pH levels. Also, individuals under low pH (salinities 14, 28 and 25) and exposed to pH 7.8 and salinity 28 (control) tend to present a similar response pattern. These

Characterizing the correlation between dephosphorization and solution pH in a calcined water treatment plant sludge.

PubMed

Zhou, Zhenming; Liu, Qidi; Li, Shuwen; Li, Fei; Zou, Jing; Liao, Xiaobin; Yuan, Baoling; Sun, Wenjie

2018-04-26

This study focused on characterizing the correlation between the dephosphorization process of calcined water treatment plant sludge (C-WTPS) and the solution initial pH in batch experiments. The specific aim was to illustrate the effect of different initial pH on the adsorption and desorption of phosphorous in C-WTPS. In addition, the effects of solution initial pH on the release of ammonia nitrogen and total organic carbon (TOC) from C-WTPS and the change of pH after adsorption were also investigated. The results demonstrated that the initial pH significantly influenced the adsorption of phosphorus on C-WTPS. When initial pH was increased from 3 to 10, the phosphorous absorption capacity reduced by 76.5%. Especially, when the initial pH reached to 11, the phosphorus adsorption capacity became a negative value, indicating that C-WTPS released phosphorus into the solution. The addition of C-WTPS to the solution had little impact on the initial pH of the solution. The absorbed phosphorous on C-WTPS was relatively stable in the pH range of 3 to 10. Nevertheless, when the solution pH was higher than 11, it can be easily released into the solution. Furthermore, by comparison with WTPS, C-WTPS released less ammonia nitrogen and TOC into the solution and adsorbed more phosphorus from the solution in the experimental pH range. Therefore, C-WTPS is more suitable to serve as a cost-effective sorbent for phosphorus removal.

Slime coating of kaolinite on chalcopyrite in saline water flotation

NASA Astrophysics Data System (ADS)

Li, Zhi-li; Rao, Feng; Song, Shao-xian; Li, Yan-mei; Liu, Wen-biao

2018-05-01

In saline water flotation, the salinity can cause a distinguishable slime coating of clay minerals on chalcopyrite particles through its effect on their electrical double layers in aqueous solutions. In this work, kaolinite was used as a representative clay mineral for studying slime coating during chalcopyrite flotation. The flotation of chalcopyrite in the presence and absence of kaolinite in tap water, seawater, and gypsum-saturated water and the stability of chalcopyrite and kaolinite particles in slurries are presented. Zeta-potential distributions and scanning electron microscopy images were used to characterize and explain the different slime coating degrees and the different flotation performances. Kaolinite particles induced slime coating on chalcopyrite surfaces and reduced chalcopyrite floatability to the greatest extent when the pH value was in the alkaline range. At 0.24wt% of kaolinite, the chalcopyrite floatability was depressed by more than 10% at alkaline pH levels in tap water. Salinity in seawater and gypsum-saturated water compressed the electrical double layers and resulted in extensive slime coating.

Salinization of the soil solution decreases the further accumulation of salt in the root zone of the halophyte Atriplex nummularia Lindl. growing above shallow saline groundwater.

PubMed

Alharby, Hesham F; Colmer, Timothy D; Barrett-Lennard, Edward G

2018-01-01

Water use by plants in landscapes with shallow saline groundwater may lead to the accumulation of salt in the root zone. We examined the accumulation of Na + and Cl - around the roots of the halophyte Atriplex nummularia Lindl. and the impacts of this increasing salinity for stomatal conductance, water use and growth. Plants were grown in columns filled with a sand-clay mixture and connected at the bottom to reservoirs containing 20, 200 or 400 mM NaCl. At 21 d, Na + and Cl - concentrations in the soil solution were affected by the salinity of the groundwater, height above the water table and the root fresh mass density at various soil depths (P < 0.001). However, by day 35, the groundwater salinity and height above the water table remained significant factors, but the root fresh mass density was no longer significant. Regression of data from the 200 and 400 mM NaCl treatments showed that the rate of Na + accumulation in the soil increased until the Na + concentration reached ~250 mM within the root zone; subsequent decreases in accumulation were associated with decreases in stomatal conductance. Salinization of the soil solution therefore had a feedback effect on further salinization within the root zone. © 2017 John Wiley & Sons Ltd.

In vitro analysis of the physical properties of contact lens blister pack solutions.

PubMed

Menzies, Kara L; Jones, Lyndon

2011-04-01

Since the initial development of silicone hydrogels, many modifications to the bulk and surface properties of the lenses have been undertaken to improve the wettability and comfort of the lenses. Recently, manufacturers have incorporated various "wetting agents" or surface-active agents into the blister packaging solutions (BPSs) of the lenses to improve initial comfort of the lens on eye. The purpose of this study was to measure and compare the pH, surface tension (ST), viscosity, and osmolality of BPSs for a variety of silicone hydrogel and polyHEMA-based hydrogel lenses. In addition, two saline solutions were tested for comparison purposes. The pH, osmolality, ST, and viscosity were measured for the BPSs for lotrafilcon B and lotrafilcon A and lotrafilcon B with a "modified BPS" (m-lotrafilcon A, m-lotrafilcon B) (CIBA Vision, Duluth, GA); balafilcon A (Bausch & Lomb, Rochester, NY); galyfilcon A, senofilcon A, and narafilcon A (Johnson & Johnson, Jacksonville, FL); and comfilcon A and enfilcon A (CooperVision, Pleasanton, CA) and BPSs from two conventional polyHEMA-based materials-etafilcon A (Johnson & Johnson) and omafilcon A (CooperVision). The two saline solutions tested were Unisol (Alcon, Fort Worth, TX) and Softwear Saline (CIBA Vision). The pH results for the two saline solutions and all BPSs remained in the pH range of tears (6.6-7.8). The ST of the modified BPS was significantly lower (p < 0.01) than the original non-modified BPS. Viscosity measurements ranged between 0.90 and 1.00 cP for all BPSs and saline solutions, except for the modified BPS, which had significantly higher viscosities (p < 0.001). Osmolality measurements were not significantly different (p > 0.05) between BPSs made by the same manufacturer but were significantly different compared with BPSs made by different manufacturers (p < 0.05). The incorporation of wetting agents and surfactants into BPSs does alter the physical properties of the BPSs, which may have clinical implications

Behavior of pure gallium in water and various saline solutions.

PubMed

Horasawa, N; Nakajima, H; Takahashi, S; Okabe, T

1997-12-01

This study investigated the chemical stability of pure gallium in water and saline solutions in order to obtain fundamental knowledge about the corrosion mechanism of gallium-based alloys. A pure gallium plate (99.999%) was suspended in 50 mL of deionized water, 0.01%, 0.1% or 1% NaCl solution at 24 +/- 2 degrees C for 1, 7, or 28 days. The amounts of gallium released into the solutions were determined by atomic absorption spectrophotometry. The surfaces of the specimens were examined after immersion by x-ray diffractometry (XRD) and x-ray photoelectron spectroscopy (XPS). In the solutions containing 0.1% or more NaCl, the release of gallium ions into the solution was lowered when compared to deionized water after 28-day immersion. Gallium oxide monohydroxide was found by XRD on the specimens immersed in deionized water after 28-day immersion. XPS indicated the formation of gallium oxide/hydroxide on the specimens immersed in water or 0.01% NaCl solution. The chemical stability of pure solid gallium was strongly affected by the presence of Cl- ions in the aqueous solution.

Metrological challenges for measurements of key climatological observables: Oceanic salinity and pH, and atmospheric humidity. Part 1: Overview

PubMed Central

Feistel, R; Wielgosz, R; Bell, S A; Camões, M F; Cooper, J R; Dexter, P; Dickson, A G; Fisicaro, P; Harvey, A H; Heinonen, M; Hellmuth, O; Kretzschmar, H-J; Lovell-Smith, J W; McDougall, T J; Pawlowicz, R; Ridout, P; Seitz, S; Spitzer, P; Stoica, D; Wolf, H

2016-01-01

Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth’s radiation balance, atmospheric water vapour is the strongest “greenhouse” gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. On climatic time scales, melting ice caps and regional deviations of the hydrological cycle result in changes of seawater salinity, which in turn may modify the global circulation of the oceans and their ability to store heat and to buffer anthropogenically produced carbon dioxide. In this paper, together with three companion articles, we examine the climatologically relevant quantities ocean salinity, seawater pH and atmospheric relative humidity, noting fundamental deficiencies in the definitions of those key observables, and their lack of secure foundation on the International System of Units, the SI. The metrological histories of those three quantities are reviewed, problems with their current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures, BIPM, in cooperation with the International Association for the Properties of Water and Steam, IAPWS, along with other international organisations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems in climatology. PMID:26900179

Acid-base and hemodynamic status of patients with intraoperative hemorrhage using two solution types: Crystalloid Ringer lactate and 1.3% sodium bicarbonate in half-normal saline solution.

PubMed

Hashemi, Sayed Jalal; Heidari, Sayed Morteza; Yaraghi, Ahmad; Seirafi, Reza

2016-01-01

Intraoperative hemorrhage is one of the problems during surgery and, if it happens in a high volume without an immediate action to control, it can be fatal. Nowadays, various injectable solutions are used. The aim of this study was to compare the acid-base and hemodynamic status of the patient using two solutions, Ringer lactate and 1.3% sodium bicarbonate, in half saline solution. This clinical trial was performed at the Al-Zahra Hospital in 2013 on 66 patients who were randomly selected and put in two studied groups at the onset of hemorrhage. For the first group, crystalloid Ringer lactate solution and for the second group, 1.3% sodium bicarbonate in half-normal saline solution was used. Electrocardiogram, heart rate, O2 saturation non-invasive blood pressure and end-tidal CO2 were monitored. The arterial blood gas, blood electrolytes, glucose and blood urea nitrogen were measured before serum and blood injection. After the infusion of solutions and before blood transfusions, another sample was sent for measurement of blood parameters. Data were analyzed using SPSS software. The mean arterial pressure was significantly higher in the second group than in the first group at some times after the infusion of solutions. pHh levels, base excess, bicarbonate, sodium, strong ion differences and osmolarity were significantly greater and potassium and chloride were significantly lower in the second group than in the first group after the infusion of solutions. 1.3% sodium bicarbonate in half-normal saline solution can lead to a proper correction of hemodynamic instability. By maintaining hemodynamic status, osmolarity and electrolytes as well as better balance of acid-base, 1.3% sodium bicarbonate solution in half-normal saline solution can be more effective than Ringer lactate solution during intraoperative bleeding.

The relationship between CDOM and salinity in estuaries: An analytical and graphical solution

NASA Astrophysics Data System (ADS)

Bowers, D. G.; Brett, H. L.

2008-09-01

The relationship between coloured dissolved organic matter (CDOM) and salinity in an estuary is explored using a simple box model in which the river discharge and concentration of CDOM in the river are allowed to vary with time. The results are presented as analytical and graphical solutions. The behaviour of the estuary depends upon the ratio, β, of the flushing time of the estuary to the timescale of the source variation. For small values of β, the variation in CDOM concentration in the estuary tracks that in the source, producing a linear relationship on a CDOM-salinity plot. As β increases, the estuary struggles to keep up with the changes in the source; and a curved CDOM-salinity plot results. For very large values of β, however, corresponding to estuaries with a long flushing time, the CDOM concentration in the estuary settles down to a mean value which again lies on a straight line on a CDOM-salinity plot (and extrapolates to the time-mean concentration in the source). The results are discussed in terms of the mapping of surface salinity in estuaries through the visible band remote sensing of CDOM.

Electrocapillary Phenomena at Edible Oil/Saline Interfaces.

PubMed

Nishimura, Satoshi; Ohzono, Takuya; Shoji, Kohei; Yagihara, Shin; Hayashi, Masafumi; Tanaka, Hisao

2017-03-01

Interfacial tension between edible oil and saline was measured under applied electric fields to understand the electrocapillary phenomena at the edible oil/saline interfaces. The electric responses of saline droplets in edible oil were also observed microscopically to examine the relationship between the electrocapillary phenomena and interfacial polarization. When sodium oleate (SO) was added to edible oil (SO-oil), the interfacial tension between SO-oil and saline decreased. However, no decrease was observed for additive-free oil or oleic acid (OA)-added oil (OA-oil). Microscopic observations suggested that the magnitude of interfacial polarization increased in the order of additive-free oil < OA-oil < SO-oil. The difference in electrocapillary phenomena between OA- and SO-oils was closely related to the polarization magnitude. In the case of SO-oil, the decrease in interfacial tension was remarkably larger for saline (pH 5.4~5.6) than that for phosphate-buffered saline (PBS, pH 7.2~7.4). However, no difference was observed between the electric responses of PBS and saline droplets in SO-oil. The difference in electrocapillary phenomena for PBS and saline could not be simply explained in terms of polarization magnitude. The ratio of ionized and non-ionized OA at the interfaces changed with the saline pH, possibly leading to the above difference.

The effect of pH on phosphorus availability and speciation in an aquaponics nutrient solution.

PubMed

Cerozi, Brunno da Silva; Fitzsimmons, Kevin

2016-11-01

The interaction between the main ions in aquaponics nutrient solutions affects chemical composition and availability of nutrients, and nutrient uptake by plant roots. This study determined the effect of pH on phosphorus (P) speciation and availability in an aquaponics nutrient solution and used Visual MINTEQ to simulate P species and P activity. In both experimental and simulated results, P availability decreased with increase in pH of aquaponics nutrient solutions. According to simulations, P binds to several cations leaving less free phosphate ions available in solution. High pH values resulted in the formation of insoluble calcium phosphate species. The study also demonstrated the importance of organic matter and alkalinity in keeping free phosphate ions in solution at high pH ranges. It is recommended though that pH in aquaponics systems is maintained at a 5.5-7.2 range for optimal availability and uptake by plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Furfural and its biochar improve the general properties of a saline soil

NASA Astrophysics Data System (ADS)

Wu, Y.; Xu, G.; Shao, H. B.

2014-07-01

Organic materials (e.g., furfural residue) are generally believed to improve the physical and chemical properties of saline soils with low fertility. Recently, biochar has been received more attention as a possible measure to improve the carbon balance and improve soil quality in some degraded soils. However, little is known about their different amelioration of a sandy saline soil. In this study, 56 d incubation experiment was conducted to evaluate the influence of furfural and its biochar on the properties of saline soil. The results showed that both furfural and biochar greatly reduced pH, increased soil organic carbon (SOC) content and cation exchange capacity (CEC), and enhanced the available phosphorus (P) in the soil. Furfural is more efficient than biochar in reducing pH: 5% furfural lowered the soil pH by 0.5-0.8 (soil pH: 8.3-8.6), while 5% biochar decreased by 0.25-0.4 due to the loss of acidity in pyrolysis process. With respect to available P, furfural addition at a rate of 5% increased available P content by 4-6 times in comparison to 2-5 times with biochar application. In reducing soil exchangeable sodium percentage (ESP), biochar is slightly superior to furfural because soil ESP reduced by 51% and 43% with 5% furfural and 5% biochar at the end of incubation. In addition, no significant differences were observed between furfural and biochar about their capacity to retain N, P in leaching solution and to increase CEC in soil. These facts may be caused by the relatively short incubation time. In general, furfural and biochar exhibited a different effect depending on the property: furfural was more effective in decreasing pH and increasing available P, whereas biochar played a more important role in increasing SOC and reducing ESP of saline soil.

A method for calibrating pH meters using standard solutions with low electrical conductivity

NASA Astrophysics Data System (ADS)

Rodionov, A. K.

2011-07-01

A procedure for obtaining standard solutions with low electrical conductivity that reproduce pH values both in acid and alkali regions is proposed. Estimates of the maximal possible error of reproducing the pH values of these solutions are obtained.

Common buffers, media, and stock solutions.

PubMed

2001-05-01

This appendix describes the preparation of selected bacterial media and of buffers and reagents used in the manipulation of nucleic acids and proteins. Recipes for cell culture media and reagents are located elsewhere in the manual. RECIPES: Acids, concentrated stock solutions; Ammonium acetate, 10 M; Ammonium hydroxide, concentrated stock solution; ATP, 100 mM; BCIP, 5% (w/v); BSA (bovine serum albumin), 10% (100 mg/ml); Denhardt solution, 100x; dNTPs: dATP, dTTP, dCTP, and dGTP; DTT, 1 M; EDTA, 0.5 M (pH 8.0); Ethidium bromide solution; Formamide loading buffer, 2x; Gel loading buffer, 6x; HBSS (Hanks balanced salt solution); HCl, 1 M; HEPES-buffered saline, 2x; KCl, 1 M; LB medium; LB plates; Loading buffer; 2-ME, (2-mercaptoethanol)50 mM; MgCl(2), 1 M; MgSO(4), 1 M; NaCl, 5 M; NaOH, 10 M; NBT (nitroblue tetrazolium chloride), 5% (w/v); PCR amplification buffer, 10x; Phosphate-buffered saline (PBS), pH approximately 7.3; Potassium acetate buffer, 0.1 M; Potassium phosphate buffer, 0.1 M; RNase a stock solution (DNase-free), 2 mg/ml; SDS, 20%; SOC medium; Sodium acetate, 3 M; Sodium acetate buffer, 0.1 M; Sodium phosphate buffer, 0.1 M; SSC (sodium chloride/sodium citrate), 20x; SSPE (sodium chloride/sodium phosphate/EDTA), 20x; T4 DNA ligase buffer, 10x; TAE buffer, 50x; TBE buffer, 10x; TBS (Tris-buffered saline); TCA (trichloroacetic acid), 100% (w/v); TE buffer; Terrific broth (TB); TrisCl, 1 M; TY medium, 2x; Urea loading buffer, 2x.

Considerations on prevention of phlebitis and venous pain from intravenous prostaglandin E(1) administration by adjusting solution pH: in vitro manipulations affecting pH.

PubMed

Kohno, Emiko; Nishikata, Mayumi; Okamura, Noboru; Matsuyama, Kenji

2008-01-01

Prostaglandin E(1) (PGE(1); Alprostadil Alfadex) is a potent vasodilator and inhibitor of platelet aggregation used to treat patients with peripheral vascular disease. The main adverse effects of intravenous PGE(1) administration, phlebitis and venous pain, arise from the unphysiologically low pH of infusion solutions. When PGE(1) infusion solutions with a pH value greater then 6 are used, phlebitis and venous pain are considered to be avoidable. Beginning with a PGE(1) infusion solution with pH greater than 6, we add the amount of 7% sodium bicarbonate needed to bring the solution to pH 7.4 if phlebitis or venous pain develops. In the present study we established a convenient nomogram showing the relationship between the titratable acidity of various infusion solutions and the volume of 7% sodium bicarbonate required to attain pH 7.4 for preventing the phlebitis and venous pain associated with PGE(1) infusion.

Oil/water/rock wettability: Influencing factors and implications for low salinity water flooding in carbonate reservoirs

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

Chen, Yongqiang; Xie, Quan; Sari, Ahmad

Wettability of the oil/brine/rock system is an essential petro-physical parameter which governs subsurface multiphase flow behaviour and the distribution of fluids, thus directly affecting oil recovery. Recent studies [1–3] show that manipulation of injected brine composition can enhance oil recovery by shifting wettability from oil-wet to water-wet. However, what factor(s) control system wettability has not been completely elucidated due to incomplete understanding of the geochemical system. To isolate and identify the key factors at play we used in this paper SO 4 2—free solutions to examine the effect of salinity (formation brine/FB, 10 times diluted formation brine/10 dFB, and 100more » times diluted formation brine/100 dFB) on the contact angle of oil droplets at the surface of calcite. We then compared contact angle results with predictions of surface complexation by low salinity water using PHREEQC software. We demonstrate that the conventional dilution approach likely triggers an oil-wet system at low pH, which may explain why the low salinity water EOR-effect is not always observed by injecting low salinity water in carbonated reservoirs. pH plays a fundamental role in the surface chemistry of oil/brine interfaces, and wettability. Our contact angle results show that formation brine triggered a strong water-wet system (35°) at pH 2.55, yet 100 times diluted formation brine led to a strongly oil-wet system (contact angle = 175°) at pH 5.68. Surface complexation modelling correctly predicted the wettability trend with salinity; the bond product sum ([>CaOH 2 +][–COO -] + [>CO 3 -][–NH +] + [>CO 3 -][–COOCa +]) increased with decreasing salinity. Finally, at pH < 6 dilution likely makes the calcite surface oil-wet, particularly for crude oils with high base number. Yet, dilution probably causes water wetness at pH > 7 for crude oils with high acid number.« less

Oil/water/rock wettability: Influencing factors and implications for low salinity water flooding in carbonate reservoirs

DOE PAGES

Chen, Yongqiang; Xie, Quan; Sari, Ahmad; ...

2017-11-21

Wettability of the oil/brine/rock system is an essential petro-physical parameter which governs subsurface multiphase flow behaviour and the distribution of fluids, thus directly affecting oil recovery. Recent studies [1–3] show that manipulation of injected brine composition can enhance oil recovery by shifting wettability from oil-wet to water-wet. However, what factor(s) control system wettability has not been completely elucidated due to incomplete understanding of the geochemical system. To isolate and identify the key factors at play we used in this paper SO 4 2—free solutions to examine the effect of salinity (formation brine/FB, 10 times diluted formation brine/10 dFB, and 100more » times diluted formation brine/100 dFB) on the contact angle of oil droplets at the surface of calcite. We then compared contact angle results with predictions of surface complexation by low salinity water using PHREEQC software. We demonstrate that the conventional dilution approach likely triggers an oil-wet system at low pH, which may explain why the low salinity water EOR-effect is not always observed by injecting low salinity water in carbonated reservoirs. pH plays a fundamental role in the surface chemistry of oil/brine interfaces, and wettability. Our contact angle results show that formation brine triggered a strong water-wet system (35°) at pH 2.55, yet 100 times diluted formation brine led to a strongly oil-wet system (contact angle = 175°) at pH 5.68. Surface complexation modelling correctly predicted the wettability trend with salinity; the bond product sum ([>CaOH 2 +][–COO -] + [>CO 3 -][–NH +] + [>CO 3 -][–COOCa +]) increased with decreasing salinity. Finally, at pH < 6 dilution likely makes the calcite surface oil-wet, particularly for crude oils with high base number. Yet, dilution probably causes water wetness at pH > 7 for crude oils with high acid number.« less

Structural adaptations of octaheme nitrite reductases from haloalkaliphilic Thioalkalivibrio bacteria to alkaline pH and high salinity.

PubMed

Popinako, Anna; Antonov, Mikhail; Tikhonov, Alexey; Tikhonova, Tamara; Popov, Vladimir

2017-01-01

Bacteria Tv. nitratireducens and Tv. paradoxus from soda lakes grow optimally in sodium carbonate/NaCl brines at pH range from 9.5 to 10 and salinity from 0.5 to 1.5 M Na+. Octaheme nitrite reductases (ONRs) from haloalkaliphilic bacteria of genus Thioalkalivibrio are stable and active in a wide range of pH (up to 11) and salinity (up to 1 M NaCl). To establish adaptation mechanisms of ONRs from haloalkaliphilic bacteria a comparative analysis of amino acid sequences and structures of ONRs from haloalkaliphilic bacteria and their homologues from non-halophilic neutrophilic bacteria was performed. The following adaptation strategies were observed: (1) strategies specific for halophilic and alkaliphilic proteins (an increase in the number of aspartate and glutamate residues and a decrease in the number of lysine residues on the protein surface), (2) strategies specific for halophilic proteins (an increase in the arginine content and a decrease in the number of hydrophobic residues on the solvent-accessible protein surface), (3) strategies specific for alkaliphilic proteins (an increase in the area of intersubunit hydrophobic contacts). Unique adaptation mechanism inherent in the ONRs from bacteria of genus Thioalkalivibrio was revealed (an increase in the core in the number of tryptophan and phenylalanine residues, and an increase in the number of small side chain residues, such as alanine and valine, in the core).

Irrigation solutions in open fractures of the lower extremities: evaluation of isotonic saline and distilled water.

PubMed

Olufemi, Olukemi Temiloluwa; Adeyeye, Adeolu Ikechukwu

2017-01-01

Open fractures are widely considered as orthopaedic emergencies requiring immediate intervention. The initial management of these injuries usually affects the ultimate outcome because open fractures may be associated with significant morbidity. Wound irrigation forms one of the pivotal principles in the treatment of open fractures. The choice of irrigation fluid has since been a source of debate. This study aimed to evaluate and compare the effects of isotonic saline and distilled water as irrigation solutions in the management of open fractures of the lower extremities. Wound infection and wound healing rates using both solutions were evaluated. This was a prospective hospital-based study of 109 patients who presented to the Accident and Emergency department with open lower limb fractures. Approval was sought and obtained from the Ethics Committee of the Hospital. Patients were randomized into either the isotonic saline (NS) or the distilled water (DW) group using a simple ballot technique. Twelve patients were lost to follow-up, while 97 patients were available until conclusion of the study. There were 50 patients in the isotonic saline group and 47 patients in the distilled water group. Forty-one (42.3%) of the patients were in the young and economically productive strata of the population. There was a male preponderance with a 1.7:1 male-to-female ratio. The wound infection rate was 34% in the distilled water group and 44% in the isotonic saline group (p = 0.315). The mean time ± SD to wound healing was 2.7 ± 1.5 weeks in the distilled water group and 3.1 ± 1.8 weeks in the isotonic saline group (p = 0.389). It was concluded from this study that the use of distilled water compares favourably with isotonic saline as an irrigation solution in open fractures of the lower extremities. © The Authors, published by EDP Sciences, 2017.

Solution and surface chemistry of the Se(IV)-Fe(0) reactions: Effect of initial solution pH.

PubMed

Xia, Xuefen; Ling, Lan; Zhang, Wei-Xian

2017-02-01

Aspects of solution and solid-phase reactions between selenite (Se(IV)) and nanoscale zero-valent iron (nZVI) were investigated. Experimental results on the effects of initial solution pH, formation and evolution of nZVI corrosion products, and speciation of selenium in nZVI were presented. In general, the rate of Se(IV) removal decreases with increasing initial pH. The observed rate constants of Se(IV) removal decreased from 0.3530 to 0.0364 min -1 as pH increased from 4.0 to 10.0. Composition and morphology of nZVI corrosion products and selenium species were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Results confirmed that Se(IV) was reduced to Se(0) and Se(-II) by nZVI. Lower solution pH favored further reduction of Se(0) to Se(-II). Amorphous FeOOH, magnetite/maghemite (Fe 3 O 4 /γ-Fe 2 O 3 ) and ferrous hydroxide (Fe(OH) 2 ) were identified as the main corrosion products. Under alkaline conditions, the corrosion products were mainly of Fe(OH) 2 along with small amounts of Fe 3 O 4 , while nZVI in acidic solutions was oxidized to mostly Fe 3 O 4 and amorphous FeOOH. Furthermore, these corrosion products acted as intermediates for electron transfer and reactive/sorptive sites for Se(IV) adsorption and reduction, thus played a crucial role in the removal of aqueous Se(IV). Copyright © 2016. Published by Elsevier Ltd.

Dynamic changes in water and salinity in saline-alkali soils after simulated irrigation and leaching.

PubMed

Wang, Shutao; Feng, Qian; Zhou, Yapeng; Mao, Xiaoxi; Chen, Yaheng; Xu, Hao

2017-01-01

Soil salinization is a global problem that limits agricultural development and impacts human life. This study aimed to understand the dynamic changes in water and salinity in saline-alkali soil based on an indoor soil column simulation. We studied the changes in the water and salt contents of soils with different degrees of salinization under various irrigation conditions. The results showed that after seven irrigations, the pH, conductivity and total soluble salt content of the percolation samples after irrigation generally increased initially then decreased with repeated irrigation. The soil moisture did not change significantly after irrigation. The pH, conductivity, and total soluble salt content of each layer of the soil profile exhibited general declining trends. In the soil profile from Changguo Township (CG), the pH decreased from 8.21-8.35 to 7.71-7.88, the conductivity decreased from 0.95-1.14 ms/cm to 0.45-0.68 ms/cm, and the total soluble salt content decreased from 2.63-2.81 g/kg to 2.28-2.51 g/kg. In the soil profile from Zhongjie Industrial Park (ZJ), the pH decreased from 8.36-8.54 to 7.73-7.96, the conductivity decreased from 1.58-1.68 ms/cm to 1.45-1.54 ms/cm, and the total soluble salt decreased from 2.81-4.03 g/kg to 2.56-3.28 g/kg. The transported salt ions were primarily K+, Na+ and Cl-. After several irrigations, a representative desalination effect was achieved. The results of this study can provide technical guidance for the comprehensive management of saline-alkali soils.

Light induced changes of internal pH in a barnacle photoreceptor and the effect of internal pH on the receptor potential.

PubMed Central

Brown, H M; Meech, R W

1979-01-01

1. Intracellular pH (pH1) was measured in Balanus photoreceptors using pH-sensitive glass micro-electrodes. The average pH1 of twelve photoreceptors which had been dark adapted for at least 30 min was 7.3 +/- 0.07 (S.D.). 2. Illumination reduced the recorded pH1 by as much as 0.2 pH unit. The change in pH1 was graded with light intensity. 3. When the cells were exposed to CO2 in the dark, pH1 declined monophasically. Saline equilibrated with 2% CO2; 98% O2 produced a steady reduction in pH1 of about 0.25 unit in 2--3 min. The buffering capacity of the receptor cell cytoplasm calculated from such experiments is approximately 15 slykes. 4. In the presence of HCO3-1, CO2 saline produced smaller, biphasic changes in pH1. 5. The membrane depolarization produced by a bright flash (depolarizing receptor potential) was reversibly reduced in the presence of external CO2 or by injection of H+. Iontophoretic injection of HCO2- increased the amplitude of the receptor potential. 6. In individual cells there was a close correlation between the amplitude of the receptor potential and pH1. 7. Saline equilibrated with CO2 reduced the light induced current (recorded under voltage-clamp) by 40--50% without affecting its reversal potential. 8. Exposure of the receptor to 95% CO2 saline for several minutes (pH0 5.5) not only abolished the receptor potential but also reversibly decreased the K conductance of the membrane in the dark. These effects were not reproduced by pH0 5.5 buffered saline or by a 5 min exposure to saline equilibrated with N2. 9. It is suggested that changes in pH1 induced by light modulate the sensitivity of the receptor under physiological conditions. PMID:43890

Dielectric properties characterization of saline solutions by near-field microwave microscopy

NASA Astrophysics Data System (ADS)

Gu, Sijia; Lin, Tianjun; Lasri, Tuami

2017-01-01

Saline solutions are of a great interest when characterizations of biological fluids are targeted. In this work a near-field microwave microscope is proposed for the characterization of liquids. An interferometric technique is suggested to enhance measurement sensitivity and accuracy. The validation of the setup and the measurement technique is conducted through the characterization of a large range of saline concentrations (0-160 mg ml-1). Based on the measured resonance frequency shift and quality factor, the complex permittivity is successfully extracted as exhibited by the good agreement found when comparing the results to data obtained from Cole-Cole model. We demonstrate that the near field microwave microscope (NFMM) brings a great advantage by offering the possibility to select a resonance frequency and a quality factor for a given concentration level. This method provides a very effective way to largely enhance the measurement sensitivity in high loss materials.

Freshwater salinization syndrome on a continental scale

PubMed Central

Likens, Gene E.; Pace, Michael L.; Utz, Ryan M.; Haq, Shahan; Gorman, Julia; Grese, Melissa

2018-01-01

Salt pollution and human-accelerated weathering are shifting the chemical composition of major ions in fresh water and increasing salinization and alkalinization across North America. We propose a concept, the freshwater salinization syndrome, which links salinization and alkalinization processes. This syndrome manifests as concurrent trends in specific conductance, pH, alkalinity, and base cations. Although individual trends can vary in strength, changes in salinization and alkalinization have affected 37% and 90%, respectively, of the drainage area of the contiguous United States over the past century. Across 232 United States Geological Survey (USGS) monitoring sites, 66% of stream and river sites showed a statistical increase in pH, which often began decades before acid rain regulations. The syndrome is most prominent in the densely populated eastern and midwestern United States, where salinity and alkalinity have increased most rapidly. The syndrome is caused by salt pollution (e.g., road deicers, irrigation runoff, sewage, potash), accelerated weathering and soil cation exchange, mining and resource extraction, and the presence of easily weathered minerals used in agriculture (lime) and urbanization (concrete). Increasing salts with strong bases and carbonates elevate acid neutralizing capacity and pH, and increasing sodium from salt pollution eventually displaces base cations on soil exchange sites, which further increases pH and alkalinization. Symptoms of the syndrome can include: infrastructure corrosion, contaminant mobilization, and variations in coastal ocean acidification caused by increasingly alkaline river inputs. Unless regulated and managed, the freshwater salinization syndrome can have significant impacts on ecosystem services such as safe drinking water, contaminant retention, and biodiversity. PMID:29311318

Properties of edible films based on pullulan-chitosan blended film-forming solutions at different pH

USDA-ARS?s Scientific Manuscript database

Influences of solution pH on the properties of pullulan-chitosan blended (Pul-Chi) films and the rheological properties of film-forming solutions were investigated. The extended conformation of chitosan in pH 4.0 solution increased intermolecular interactions with pullulan compared to the more compa...

The Effect of Temperature and Solution pH on Tetragonal Lysozyme Nucleation Kinetics

NASA Technical Reports Server (NTRS)

Judge, Russell A.; Jacobs, Randolph S.; Frazier, Tyralynn; Snell, Edward H.; Pusey, Marc L.

1998-01-01

Part of the challenge of macromolecular crystal growth for structure determination is obtaining an appropriate number of crystals with a crystal volume suitable for x-ray analysis. In this respect an understanding of the effect of solution conditions on macromolecule nucleation rates is advantageous. This study investigated the effects of supersaturation, temperature and pH on the nucleation rate of tetragonal lysozyme crystals. Batch crystallization plates were prepared at given solution concentrations and incubated at set temperatures over one week. The number of crystals per well with their size and axial ratios were recorded and correlated with solution conditions, Duplicate experiments indicate the reproducibility of the technique, Crystal numbers were found to increase with increasing supersaturation and temperature. The most significant variable however, was pH, where crystal numbers changed by two orders of magnitude over the pH range 4.0 to 5.2. Crystal size varied also with solution conditions, with the largest crystals being obtained at pH 5.2. Having optimized the crystallization conditions, a batch of crystals were prepared under exactly the same conditions and fifty of these crystals were analyzed by x-ray techniques. The results indicate that even under the same crystallization conditions, a marked variation in crystal properties exists.

Photolysis of 2,4,6-trinitrotoluene in seawater and estuary water: Impact of pH, temperature, salinity, and dissolved organic matter.

PubMed

Luning Prak, Dianne J; Breuer, James E T; Rios, Evelyn A; Jedlicka, Erin E; O'Sullivan, Daniel W

2017-01-30

The influence of salinity, pH, temperature, and dissolved organic matter on the photolysis rate of 2,4,6-trinitrotoluene (TNT) in marine, estuary, and laboratory-prepared waters was studied using a Suntest CPS+® solar simulator equipped with optical filters. TNT degradation rates were determined using HPLC analysis, and products were identified using LC/MS. Minimal or no TNT photolysis occurred under a 395-nm long pass filter, but under a 295-nm filter, first-order TNT degradation rate constants and apparent quantum yields increased with increasing salinity in both natural and artificial seawater. TNT rate constants increased slightly with increasing temperature (10 to 32°C) but did not change significantly with pH (6.4 to 8.1). The addition of dissolved organic matter (up to 5mg/L) to ultrapure water, artificial seawater, and natural seawater increased the TNT photolysis rate constant. Products formed by TNT photolysis in natural seawater were determined to be 2,4,6-trinitrobenzaldehyde, 1,3,5-trinitrobenzene, 2,4,6-trinitrobenzoic acid, and 2-amino-4,6-dinitrobenzoic acid. Published by Elsevier Ltd.

Role of solute-transport models in the analysis of groundwater salinity problems in agricultural areas

USGS Publications Warehouse

Konikow, Leonard F.

1981-01-01

Undesirable salinity increases occur in both groundwater and surface water and are commonly related to agricultural practices. Groundwater recharge from precipitation or irrigation will transport and disperse residual salts concentrated by evapotranspiration, salts leached from soil and aquifer materials, as well as some dissolved fertilizers and pesticides. Where stream salinity is affected by agricultural practices, the increases in salt load usually are attributable mostly to a groundwater component of flow. Thus, efforts to predict, manage, or control stream salinity increases should consider the role of groundwater in salt transport. Two examples of groundwater salinity problems in Colorado, U.S.A., illustrate that a model which simulates accurately the transport and dispersion of solutes in flowing groundwater can be (1) a valuable investigative tool to help understand the processes and parameters controlling the movement and fate of the salt, and (2) a valuable management tool for predicting responses and optimizing the development and use of the total water resource. ?? 1981.

Dynamic changes in water and salinity in saline-alkali soils after simulated irrigation and leaching

PubMed Central

Feng, Qian; Mao, Xiaoxi

2017-01-01

Soil salinization is a global problem that limits agricultural development and impacts human life. This study aimed to understand the dynamic changes in water and salinity in saline-alkali soil based on an indoor soil column simulation. We studied the changes in the water and salt contents of soils with different degrees of salinization under various irrigation conditions. The results showed that after seven irrigations, the pH, conductivity and total soluble salt content of the percolation samples after irrigation generally increased initially then decreased with repeated irrigation. The soil moisture did not change significantly after irrigation. The pH, conductivity, and total soluble salt content of each layer of the soil profile exhibited general declining trends. In the soil profile from Changguo Township (CG), the pH decreased from 8.21–8.35 to 7.71–7.88, the conductivity decreased from 0.95–1.14 ms/cm to 0.45–0.68 ms/cm, and the total soluble salt content decreased from 2.63–2.81 g/kg to 2.28–2.51 g/kg. In the soil profile from Zhongjie Industrial Park (ZJ), the pH decreased from 8.36–8.54 to 7.73–7.96, the conductivity decreased from 1.58–1.68 ms/cm to 1.45–1.54 ms/cm, and the total soluble salt decreased from 2.81–4.03 g/kg to 2.56–3.28 g/kg. The transported salt ions were primarily K+, Na+ and Cl-. After several irrigations, a representative desalination effect was achieved. The results of this study can provide technical guidance for the comprehensive management of saline-alkali soils. PMID:29091963

The effect of retreatment procedure on the pH changes at the surface of root dentin using two different calcium hydroxide pastes.

PubMed

Kazemipoor, Maryam; Tabrizizadeh, Mehdi; Dastani, Milad; Hakimian, Roqayeh

2012-10-01

To compare pH changes at the cervical, middle and apical surfaces of root dentin in retreated and non- retreated teeth, after canal obturation with two different calcium hydroxide pastes. After instrumentation of 55 extracted teeth, three cavities with 0.75 mm depth and 1.5 mm in diameter were drilled at buccal root surface. The teeth were randomly divided into five groups. Canals in the first two groups were filled with either mixture of calcium hydroxide and saline solution and calcium hydroxide and 2% chlorhexidine (CHX). In the third and fourth groups canals were first obturated with gutta-percha and AH26 sealer, and then materials were removed. After 2 days canals were filled with two different calcium hydroxide pastes similar to the first and the second groups. The pH was measured in the prepared cavities at 1, 3, 7 and 14 days. In the non-retreated groups, pH at the surface of the roots was significantly higher in comparison to the retreated ones (P value < 0.001). pH values were significantly higher in the non-retreated teeth filling with calcium hydroxide and saline solution (P value < 0.001). Regarding to the little pH changes at the surface of dentin in retreated teeth, the hydroxyl ions cannot penetrate into the dentinal tubules. Thus, to achieve higher pH at the root surface in retreated teeth, it is clinically advisable to remove more dentin from the inner walls and to use normal saline as a vehicle for calcium hydroxide rather than acidic pH materials.

Automated pH Control of Nutrient Solution in a Hydroponic Plant Growth System

NASA Technical Reports Server (NTRS)

Smith, B.; Dogan, N.; Aglan, H.; Mortley, D.; Loretan, P.

1998-01-01

Over, the years, NASA has played an important role in providing to and the development of automated nutrient delivery and monitoring, systems for growing crops hydroponically for long term space missions. One example are the systems used in the Biomass Production Chamber (BPC) at Kennedy Space Center (KSC). The current KSC monitoring system is based on an engineering workstation using standard analog/digital input/output hardware and custom written software. The monitoring system uses completely separate sensors to provide a check of control sensor accuracy and has the ability to graphically display and store data form past experiment so that they are available for data analysis [Fortson, 1992]. In many cases, growing systems have not been fitted with the kind of automated control systems as used at KSC. The Center for Food and Environmental Systems for Human Exploration of Space (CFESH) located on the campus of Tuskegee University, has effectively grown sweetpotatoes and peanuts hydroponically for the past five years. However they have adjusted the pH electrical conductivity and volume of the hydroponic nutrient solution only manually at times when the solution was to be replenished or changed out according to its protocol (e.g. one-week, two-week, or two-day cycle). But the pH of the nutrient solution flowing through the channel is neither known nor controlled between the update, change out, or replenishment period. Thus, the pH of the nutrient solution is not held at an optimum level over the span of the plant's growth cycle. To solve this dilemma, an automated system for the control and data logging of pH data relative to sweetpotato production using the nutrient film technique (NFT) has been developed, This paper discusses a microprocessor-based system, which was designed to monitor, control, and record the pH of a nutrient solution used for growing sweetpotatoes using NFT.

Freshwater salinization syndrome on a continental scale.

PubMed

Kaushal, Sujay S; Likens, Gene E; Pace, Michael L; Utz, Ryan M; Haq, Shahan; Gorman, Julia; Grese, Melissa

2018-01-23

Salt pollution and human-accelerated weathering are shifting the chemical composition of major ions in fresh water and increasing salinization and alkalinization across North America. We propose a concept, the freshwater salinization syndrome, which links salinization and alkalinization processes. This syndrome manifests as concurrent trends in specific conductance, pH, alkalinity, and base cations. Although individual trends can vary in strength, changes in salinization and alkalinization have affected 37% and 90%, respectively, of the drainage area of the contiguous United States over the past century. Across 232 United States Geological Survey (USGS) monitoring sites, 66% of stream and river sites showed a statistical increase in pH, which often began decades before acid rain regulations. The syndrome is most prominent in the densely populated eastern and midwestern United States, where salinity and alkalinity have increased most rapidly. The syndrome is caused by salt pollution (e.g., road deicers, irrigation runoff, sewage, potash), accelerated weathering and soil cation exchange, mining and resource extraction, and the presence of easily weathered minerals used in agriculture (lime) and urbanization (concrete). Increasing salts with strong bases and carbonates elevate acid neutralizing capacity and pH, and increasing sodium from salt pollution eventually displaces base cations on soil exchange sites, which further increases pH and alkalinization. Symptoms of the syndrome can include: infrastructure corrosion, contaminant mobilization, and variations in coastal ocean acidification caused by increasingly alkaline river inputs. Unless regulated and managed, the freshwater salinization syndrome can have significant impacts on ecosystem services such as safe drinking water, contaminant retention, and biodiversity. Copyright © 2018 the Author(s). Published by PNAS.

Synergistic Action of a Microbial-based Biostimulant and a Plant Derived-Protein Hydrolysate Enhances Lettuce Tolerance to Alkalinity and Salinity

PubMed Central

Rouphael, Youssef; Cardarelli, Mariateresa; Bonini, Paolo; Colla, Giuseppe

2017-01-01

In the coming years, farmers will have to deal with growing crops under suboptimal conditions dictated by global climate changes. The application of plant biostimulants such as beneficial microorganisms and plant-derived protein hydrolysates (PHs) may represent an interesting approach for increasing crop tolerance to alkalinity and salinity. The current research aimed at elucidating the agronomical, physiological, and biochemical effects as well as the changes in mineral composition of greenhouse lettuce (Lactuca sativa L.) either untreated or treated with a microbial-based biostimulant (Tablet) containing Rhizophagus intraradices and Trichoderma atroviride alone or in combination with a PH. Plants were sprayed with PH at weekly intervals with a solution containing 2.5 ml L-1 of PH. Lettuce plants were grown in sand culture and supplied with three nutrient solutions: standard, saline (25 mM NaCl) or alkaline (10 mM NaHCO3 + 0.5 g l-1 CaCO3; pH 8.1). Salt stress triggered a decrease in fresh yield, biomass production, SPAD index, chlorophyll fluorescence, leaf mineral composition and increased leaf proline concentration, without altering antioxidant enzyme activities. The decrease in marketable yield and biomass production under alkali stress was not significant. Irrespective of nutrient solution, the application of Tablet and especially Tablet + PH increased fresh marketable yield, shoot and root dry weight. This was associated with an improvement in SPAD index, Fv/Fm ratio, CAT and GPX activities and a better nutritional status (higher P, K, and Fe and lower Na with NaCl and higher P and Fe with NaHCO3) via an increase of total root length and surface. The combination of microbial biostimulant with foliar application of PH synergistically increased the marketable fresh yield by 15.5 and 46.7% compared to the Tablet-treated and untreated plants, respectively. The improved crop performance of Tablet + PH application was attributed to a better root system

Phosphorus sorption-desorption and effects of temperature, pH and salinity on phosphorus sorption in marsh soils from coastal wetlands with different flooding conditions.

PubMed

Bai, Junhong; Ye, Xiaofei; Jia, Jia; Zhang, Guangliang; Zhao, Qingqing; Cui, Baoshan; Liu, Xinhui

2017-12-01

Wetland soils act as a sink or source of phosphorus (P) to the overlaying water due to phosphorus sorption-desorption processes. Litter information is available on sorption and desorption behaviors of phosphorus in coastal wetlands with different flooding conditions. Laboratory experiments were conducted to investigate phosphorus sorption-desorption processes, fractions of adsorbed phosphorus, and the effects of salinity, pH and temperature on phosphorus sorption on soils in tidal-flooding wetlands (TW), freshwater-flooding wetlands (FW) and seasonal-flooding wetlands (SW) in the Yellow River Delta. Our results showed that the freshly adsorbed phosphorus dominantly exists in Occluded-P and Fe/AlP and their percentages increased with increasing phosphorus adsorbed. Phosphorus sorption isotherms could be better described by the modified Langmuir model than by the modified Freundlich model. A binomial equation could be properly used to describe the effects of salinity, pH, and temperature on phosphorus sorption. Phosphorus sorption generally increased with increasing salinity, pH, and temperature at lower ranges, while decreased in excess of some threshold values. The maximum phosphorus sorption capacity (Q max ) was larger for FW soils (256 mg/kg) compared with TW (218 mg/kg) and SW soils (235 mg/kg) (p < 0.05). The percentage of phosphorus desorption (P des ) in the FW soils (7.5-63.5%) was much lower than those in TW (27.7-124.9%) and SW soils (19.2-108.5%). The initial soil organic matter, pH and the exchangeable Al, Fe and Cd contents were important factors influencing P sorption and desorption. The findings of this study indicate that freshwater restoration can contribute to controlling the eutrophication status of water bodies through increasing P sorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

NASA Astrophysics Data System (ADS)

Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

2011-01-01

Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. However, the Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

Absolute Salinity, "Density Salinity" and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

NASA Astrophysics Data System (ADS)

Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

2010-08-01

Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. The Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

Regional acidification trends in Florida shellfish estuaries: A 20+ year look at pH, oxygen, temperature, and salinity

USGS Publications Warehouse

Robbins, Lisa L.; Lisle, John T.

2018-01-01

Increasing global CO2 and local land use changes coupled with increased nutrient pollution are threatening estuaries worldwide. Local changes of estuarine chemistry have been documented, but regional associations and trends comparing multiple estuaries latitudinally have not been evaluated. Rapid climate change has impacted the annual and decadal chemical trends in estuaries, with local ecosystem processes enhancing or mitigating the responses. Here, we compare pH, dissolved oxygen, temperature, and salinity data from 10 Florida shellfish estuaries and hundreds of shellfish bed stations. Over 80,000 measurements, spanning from 1980 to 2008, taken on Atlantic Ocean and West Florida coast showed significant regional trends of consistent pH decreases in 8 out of the 10 estuaries, with an average rate of decrease on the Gulf of Mexico side estuaries of Florida of 7.3 × 10−4 pH units year−1, and average decrease on the Atlantic Coast estuaries of 5.0 × 10−4 pH units year−1. The rates are approximately 2–3.4 times slower than observed in pH decreases associated with ocean acidification in the Atlantic and Pacific. Other significant trends observed include decreasing dissolved oxygen in 9 out of the 10 estuaries, increasing salinity in 6 out of the 10, and temperature increases in 3 out of the 10 estuaries. The data provide a synoptic regional view of Florida estuary trends which reflect the complexity of changing climate and coastal ocean acidification superimposed on local conditions. These data provide context for understanding, and interpreting the past and predicting future of regional water quality health of shellfish and other organisms of commercial and ecological significance along Florida’s coasts.

Salting-out assisted liquid-liquid extraction combined with gas chromatography-mass spectrometry for the determination of pyrethroid insecticides in high salinity and biological samples.

PubMed

Niu, Zongliang; Yu, Chunwei; He, Xiaowen; Zhang, Jun; Wen, Yingying

2017-09-05

A salting-out assisted liquid-liquid extraction (SALLE) combined with gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of four pyrethroid insecticides (PYRs) in high salinity and biological samples. Several parameters including sample pH, salting-out solution volume and salting-out solution pH influencing the extraction efficiency were systematically investigated with the aid of orthogonal design. The optimal extraction conditions of SALLE were: 4mL of salting-out solution with pH=4 and the sample pH=3. Under the optimum extraction and determination conditions, good responses for four PYRs were obtained in a range of 5-5000ng/mL, with linear coefficients greater than 0.998. The recoveries of the four PYRs ranged from 74% to 110%, with standard deviations ranging from 1.8% to 9.8%. The limits of detection based on a signal-to-noise ratio of 3 were between 1.5-60.6ng/mL. The method was applied to the determination of PYRs in urine, seawater and wastewater samples with a satisfactory result. The results demonstrated that this SALLE-GC-MS method was successfully applied to determine PYRs in high salinity and biological samples. SALLE avoided the need for the elimination of salinity and protein in the sample matrix, as well as clean-up of the extractant. Most of all, no centrifugation or any special apparatus are required, make this a promising method for rapid sample preparation procedure. Copyright © 2017 Elsevier B.V. All rights reserved.

Photo-Fenton degradation of phenol, 2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenol mixture in saline solution using a falling-film solar reactor.

PubMed

Luna, Airton J; Nascimento, Cláudio A O; Foletto, Edson Luiz; Moraes, José E F; Chiavone-Filhoe, Osvaldo

2014-01-01

In this work, a saline aqueous solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a falling-film solar reactor. The influence of the parameters such as initial pH (5-7), initial concentration of Fe2+ (1-2.5mM) and rate of H202 addition (1.87-3.74mmol min-1) was investigated. The efficiency of photodegradation was determined from the removal of dissolved organic carbon (DOC), described by the species degradation of phenol, 2,4-D and 2,4-DCP. Response surface methodology was employed to assess the effects of the variables investigated, i.e. [Fe2+], [H202] and pH, in the photo-Fenton process with solar irradiation. The results reveal that the variables' initial concentration of Fe2+ and H202 presents predominant effect on pollutants' degradation in terms of DOC removal, while pH showed no influence. Under the most adequate experimental conditions, about 85% DOC removal was obtained in 180 min by using a reaction system employed here, and total removal of phenol, 2,4- and 2,4-DCP mixture in about 30min.

Finding a solution: Heparinised saline versus normal saline in the maintenance of invasive arterial lines in intensive care.

PubMed

Everson, Matthew; Webber, Lucy; Penfold, Chris; Shah, Sanjoy; Freshwater-Turner, Dan

2016-11-01

We assessed the impact of heparinised saline versus 0.9% normal saline on arterial line patency. Maintaining the patency of arterial lines is essential for obtaining accurate physiological measurements, enabling blood sampling and minimising line replacement. Use of heparinised saline is associated with risks such as thrombocytopenia, haemorrhage and mis-selection. Historical studies draw variable conclusions but suggest that normal saline is at least as effective at maintaining line patency, although recent evidence has questioned this. We conducted a prospective analysis of the use of heparinised saline versus normal saline on unselected patients in the intensive care of our hospital. Data concerning duration of 471 lines insertion and reason for removal was collected. We found a higher risk of blockage for lines flushed with normal saline compared with heparinised saline (RR = 2.15, 95% CI 1.392-3.32, p  ≤ 0.001). Of the 56 lines which blocked initially (19 heparinised saline and 37 normal saline lines), 16 were replaced with new lines; 5 heparinised saline lines and 11 normal saline lines were reinserted; 5 of these lines subsequently blocked again, 3 of which were flushed with normal saline. Our study demonstrates a clinically important reduction in arterial line longevity due to blockages when flushed with normal saline compared to heparinised saline. We have determined that these excess blockages have a significant clinical impact with further lines being inserted after blockage, resulting in increased risks to patients, wasted time and cost of resources. Our findings suggest that the current UK guidance favouring normal saline flushes should be reviewed.

Net acidity indicates the whole effluent toxicity of pH and dissolved metals in metalliferous saline waters.

PubMed

Degens, Bradley P; Krassoi, Rick; Galvin, Lynette; Reynolds, Brad; Micevska, Tina

2018-05-01

Measurements of potential acidity in water are used to manage aquatic toxicity risks of discharge from acid sulfate soils or acid mine drainage. Net acidity calculated from pH, dissolved metals and alkalinity is a common measurement of potential acidity but the relevance of current risk thresholds to aquatic organisms are unclear. Aquatic toxicity testing was carried out using four halophytic organisms with water from four saline sources in southern Western Australia (3 acidic drains and one alkaline river; 39-40 g TDS/L) where acidity was varied by adjusting pH to 4.5-6.5. The test species were brine shrimps (Artemia salina), locally sourced ostracods (Platycypris baueri), microalgae (Dunaliella salina) and amphipods (Allorchestes compressa). Testing found the EC 10 and IC 10 of net acidity ranged from -7.8 to 10.5 mg CaCO 3 /L with no survival or growth of any species at >47 mg CaCO 3 /L. Reduced net acidity indicated reduced whole effluent toxicity more reliably than increased pH alone with organisms tolerating pH up to 1.1 units lower in the absence of dissolved metals. Variation in toxicity indicated by net acidity was mostly attributed to reduced concentrations of dissolved Al and Fe combined with higher pH and alkalinity and some changes in speciation of Al and Fe with pH. These results indicate that rapid in-field assessments of net acidity in acidic, Al dominated waters may be an indicator of potential acute and sub-chronic impacts on aquatic organisms. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Stabilizing sodium hypochlorite at high pH: effects on soft tissue and dentin.

PubMed

Jungbluth, Holger; Marending, Monika; De-Deus, Gustavo; Sener, Beatrice; Zehnder, Matthias

2011-05-01

When sodium hypochlorite solutions react with tissue, their pH drops and tissue sorption decreases. We studied whether stabilizing a NaOCl solution at a high pH would increase its soft-tissue dissolution capacity and effects on the dentin matrix compared with a standard NaOCl solution of the same concentration and similar initial pH. NaOCl solutions were prepared by mixing (1:1) a 10% stock solution with water (standard) or 2 mol/L NaOH (stabilized). Physiological saline and 1 mol/L NaOH served as the controls. Chlorine content and alkaline capacity of NaOCl solutions were determined. Standardized porcine palatal soft-tissue specimens and human root dentin bars were exposed to test and control solutions. Weight loss percentage was assessed in the soft-tissue dissolution assay. Three-point bending tests were performed on the root dentin bars to determine the modulus of elasticity and flexural strength. Values between groups were compared using one-way analysis of variance with the Bonferroni correction for multiple testing (α < .05). Both solutions contained 5% NaOCl. One milliliter of the standard and the stabilized solution consumed 4.0 mL and 13.7 mL of a 0.1-mol/L HCl solution before they reached a pH level of 7.5, respectively. The stabilized NaOCl dissolved significantly more soft tissue than the standard solution, and the pH remained high. It also caused a higher loss in elastic modulus and flexure strength (P < .05) than the control solutions, whereas the standard solution did not. NaOH-stabilized NaOCl solutions have a higher alkaline capacity and are thus more proteolytic than standard counterparts. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The effect of retreatment procedure on the pH changes at the surface of root dentin using two different calcium hydroxide pastes

PubMed Central

Kazemipoor, Maryam; Tabrizizadeh, Mehdi; Dastani, Milad; Hakimian, Roqayeh

2012-01-01

Aim: To compare pH changes at the cervical, middle and apical surfaces of root dentin in retreated and non- retreated teeth, after canal obturation with two different calcium hydroxide pastes. Materials and Methods: After instrumentation of 55 extracted teeth, three cavities with 0.75 mm depth and 1.5 mm in diameter were drilled at buccal root surface. The teeth were randomly divided into five groups. Canals in the first two groups were filled with either mixture of calcium hydroxide and saline solution and calcium hydroxide and 2% chlorhexidine (CHX). In the third and fourth groups canals were first obturated with gutta-percha and AH26 sealer, and then materials were removed. After 2 days canals were filled with two different calcium hydroxide pastes similar to the first and the second groups. The pH was measured in the prepared cavities at 1, 3, 7 and 14 days. Results: In the non-retreated groups, pH at the surface of the roots was significantly higher in comparison to the retreated ones (P value < 0.001). pH values were significantly higher in the non-retreated teeth filling with calcium hydroxide and saline solution (P value < 0.001). Conclusion: Regarding to the little pH changes at the surface of dentin in retreated teeth, the hydroxyl ions cannot penetrate into the dentinal tubules. Thus, to achieve higher pH at the root surface in retreated teeth, it is clinically advisable to remove more dentin from the inner walls and to use normal saline as a vehicle for calcium hydroxide rather than acidic pH materials. PMID:23112482

The Effect of Temperature and Solution pH on the Nucleation of Tetragonal Lysozyme Crystals

NASA Technical Reports Server (NTRS)

Judge, Russell A.; Jacobs, Randolph S.; Frazier, Tyralynn; Snell, Edward H.; Pusey, Marc L.

1999-01-01

Part of the challenge of macromolecular crystal growth for structure determination is obtaining crystals with a volume suitable for x-ray analysis. In this respect an understanding of the effect of solution conditions on macromolecule nucleation rates is advantageous. This study investigated the effects of supersaturation, temperature, and pH on the nucleation rate of tetragonal lysozyme crystals. Batch crystallization plates were prepared at given solution concentrations and incubated at set temperatures over 1 week. The number of crystals per well with their size and axial ratios were recorded and correlated with solution conditions. Crystal numbers were found to increase with increasing supersaturation and temperature. The most significant variable, however, was pH; crystal numbers changed by two orders of magnitude over the pH range 4.0-5.2. Crystal size also varied with solution conditions, with the largest crystals obtained at pH 5.2. Having optimized the crystallization conditions, we prepared a batch of crystals under the same initial conditions, and 50 of these crystals were analyzed by x-ray diffraction techniques. The results indicate that even under the same crystallization conditions, a marked variation in crystal properties exists.

An inorganic CO2 diffusion and dissolution process explains negative CO2 fluxes in saline/alkaline soils.

PubMed

Ma, Jie; Wang, Zhong-Yuan; Stevenson, Bryan A; Zheng, Xin-Jun; Li, Yan

2013-01-01

An 'anomalous' negative flux, in which carbon dioxide (CO2) enters rather than is released from the ground, was studied in a saline/alkaline soil. Soil sterilization disclosed an inorganic process of CO2 dissolution into (during the night) and out of (during the day) the soil solution, driven by variation in soil temperature. Experimental and modeling analysis revealed that pH and soil moisture were the most important determinants of the magnitude of this inorganic CO2 flux. In the extreme cases of air-dried saline/alkaline soils, this inorganic process was predominant. While the diurnal flux measured was zero sum, leaching of the dissolved inorganic carbon in the soil solution could potentially effect net carbon ecosystem exchange. This finding implies that an inorganic module should be incorporated when dealing with the CO2 flux of saline/alkaline land. Neglecting this inorganic flux may induce erroneous or misleading conclusions in interpreting CO2 fluxes of these ecosystems.

An inorganic CO2 diffusion and dissolution process explains negative CO2 fluxes in saline/alkaline soils

PubMed Central

Ma, Jie; Wang, Zhong-Yuan; Stevenson, Bryan A.; Zheng, Xin-Jun; Li, Yan

2013-01-01

An ‘anomalous' negative flux, in which carbon dioxide (CO2) enters rather than is released from the ground, was studied in a saline/alkaline soil. Soil sterilization disclosed an inorganic process of CO2 dissolution into (during the night) and out of (during the day) the soil solution, driven by variation in soil temperature. Experimental and modeling analysis revealed that pH and soil moisture were the most important determinants of the magnitude of this inorganic CO2 flux. In the extreme cases of air-dried saline/alkaline soils, this inorganic process was predominant. While the diurnal flux measured was zero sum, leaching of the dissolved inorganic carbon in the soil solution could potentially effect net carbon ecosystem exchange. This finding implies that an inorganic module should be incorporated when dealing with the CO2 flux of saline/alkaline land. Neglecting this inorganic flux may induce erroneous or misleading conclusions in interpreting CO2 fluxes of these ecosystems. PMID:23778238

pH influences the biocompatibility of methylene blue solutions.

PubMed

Gusman, David Jonathan Rodrigues; Cintra, Luciano Tavares Angelo; Novaes, Vivian Cristina Noronha; Matheus, Henrique Rinaldi; de Araujo, Nathália Januario; de Almeida, Juliano Milanezi

2018-01-01

The aim of this study was to investigate the biocompatibility of methylene blue at different pH levels through the method of implantation in subcutaneous tissue. Eighty-four sterilized polyethylene tubes were allocated in the subcutaneous tissue of 28 rats, each one receiving four tubes, set into four groups: group tube (G-T)-empty tube, fibrin group (G-F)-tube filled with fibrin sponge, group methylene blue pH 7 (G-MB/pH 7)-tube filled with fibrin sponge soaked by methylene blue (100 μg/ml) at pH 7.0, and group methylene blue pH 1 (G-MB/pH 1)-tube filled with fibrin sponge and soaked by methylene blue (100 μg/ml) at pH 1.0. After 7, 15, and 30 days, seven animals from each group were euthanized, and the tubes involved by the surrounding tissue were removed and fixed with 4% buffered formaldehyde solution. The collected pieces were processed and histological sections (4 μm) were stained with hematoxylin and eosin and analyzed by light microscopy. Scores were assigned to analysis of histopathologic parameters. The results were statistically analyzed by the Kruskal-Wallis test (p ≤ 0.05). At 7 and 30 days, the G-MB/pH 1 group showed no significant difference in the G-T control group, while G-MB/pH 7 had a significant increase on tissue reaction, also when compared to G-T. At 15 days, there was no statistical difference between the groups. Within the limits of this study, it is concluded that methylene blue at pH 1.0 provides better biocompatibility than at pH 7.0.

"Biocompatible" Neutral pH Low-GDP Peritoneal Dialysis Solutions: Much Ado About Nothing?

PubMed

Misra, Paraish S; Nessim, Sharon J; Perl, Jeffrey

2017-03-01

Adverse outcomes in peritoneal dialysis (PD), including PD related infections, the loss of residual kidney function (RKF), and longitudinal, deleterious changes in peritoneal membrane function continue to limit the long-term success of PD therapy. The observation that these deleterious changes occur upon exposure to conventional glucose-based PD solutions fuels the search for a more biocompatible PD solution. The development of a novel PD solution with a neutral pH, and lower in glucose degradation products (GDPs) compared to its conventional predecessors has been labeled a "biocompatible" solution. While considerable evidence in support of these novel solutions' biocompatibility has emerged from cell culture and animal studies, the clinical benefits as compared to conventional PD solutions are less clear. Neutral pH low GDP (NpHLGDP) PD solutions appear to be effective in reducing infusion pain, but their effects on other clinical endpoints including peritoneal membrane function, preservation of RKF, PD-related infections, and technique and patient survival are less clear. The literature is limited by studies characterized by relatively few patients, short follow-up time, heterogeneity with regards to the novel PD solution type under study, and the different patient populations under study. Nonetheless, the search for a more biocompatible PD solution continues with emerging data on promising non glucose-based solutions. © 2017 Wiley Periodicals, Inc.

Molecular cloning and sequence analysis of two carbonic anhydrase in the swimming crab Portunus trituberculatus and its expression in response to salinity and pH stress.

PubMed

Pan, Luqing; Hu, Dongxu; Liu, Maoqi; Hu, Yanyan; Liu, Shengnan

2016-01-15

Carbonic anhydrase (CA) is involved in ion transport, acid-base balance and pH regulation by catalyzing the interconversion of CO2 and HCO3(-). In this study, full-length cDNA sequences of two CA isoforms were identified from Portunus trituberculatus. One was Portunus trituberculatus cytoplasmic carbonic anydrase (PtCAc) and the other one was Portunus trituberculatus glycosyl-phosphatidylinositol-linked carbonic anhydrase (PtCAg). The sequence of PtCAc was formed by an ORF of 816 bp, encoding a protein of 30.18 kDa. The PtCAg was constituted by an ORF of 927 bp, encoding a protein of 34.09 kDa. The deduced amino acid sequences of the two CA isoforms were compared to other crustacean' CA sequences. Both of them reflected high conservation of the residues and domains essential to the function of the two enzymes. The tissue expression analysis of PtCAc and PtCAg were detected in gill, muscle, hepatopancreas, hemocytes and gonad. PtCAc and PtCAg gene expressions were studied under salinity and pH challenge. The results showed that when salinity decreased (30 to 20 ppt), the mRNA expression of PtCAc increased significantly at 24 and 48 h, and the highest value appeared at 24h. The mRNA expression of PtCAg had the same situation with PtCAc. However, when salinity increased (30 to 35 ppt), only the mRNA expression of PtCAc increased significantly at 48 h. When pH changed, only the mRNA expression of PtCAc increased significantly at 12h, which was under low pH situation. The mRNA expression of PtCAg increased significantly at 12-48 h, and there was no significant difference of the expression between the pH challenged group and the control group in other experimental time. The results provided the base of understanding CA' function and the underlying mechanism in response to environmental changes in crustaceans. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of pH of spray solution on the electrical properties of cadmium oxide thin films

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

Hodlur, R. M.; Gunnagol, Raghu M.; Rabinal, M. K., E-mail: mkrabinal@yahoo.com

2015-06-24

Highly conducting transparent cadmium oxide thin films were prepared by conventional spray pyrolysis technique on glass at 375 °C substrate temperature. The pH of the spray solution was varied by adding ammonia/hydrochloric acid in the spray solution. The XRD pattern showed cubic phase. A lowest resistivity of 9.9 × 10{sup −4} Ω cm (with carrier concentration (n) = 5.1 × 10{sup 20} cm{sup −3}, mobility (µ)=12.4 cm{sup 2}/Vs) is observed for pH ∼12. The resistivity is tuned almost by three orders of magnitude by controlling the bath pH with optical transmittance more than 70 %. Thus, without any doping, the electricalmore » conductivity of CdO films could be easily tuned by simply varying the pH of spray solution without compromising the transparency and keeping the other deposition parameters fixed.« less

Ability of a haloalkaliphilic bacterium isolated from Soap Lake, Washington to generate electricity at pH 11.0 and 7% salinity.

PubMed

Paul, Varun G; Minteer, Shelley D; Treu, Becky L; Mormile, Melanie R

2014-01-01

A variety of anaerobic bacteria have been shown to transfer electrons obtained from organic compound oxidation to the surface of electrodes in microbial fuel cells (MFCs) to produce current. Initial enrichments for iron (III) reducing bacteria were set up with sediments from the haloalkaline environment of Soap Lake, Washington, in batch cultures and subsequent transfers resulted in a culture that grew optimally at 7.0% salinity and pH 11.0. The culture was used to inoculate the anode chamber of a MFC with formate as the electron source. Current densities up to 12.5 mA/m2 were achieved by this bacterium. Cyclic voltammetry experiments demonstrated that an electron mediator, methylene blue, was required to transfer electrons to the anode. Scanning electron microscopic imaging of the electrode surface did not reveal heavy colonization of bacteria, providing evidence that the bacterium may be using an indirect mode of electron transfer to generate current. Molecular characterization of the 16S rRNA gene and restriction fragment length profiles (RFLP) analysis showed that the MFC enriched for a single bacterial species with a 99% similarity to the 16S rRNA gene of Halanaerobium hydrogeniformans. Though modest, electricity production was achieved by a haloalkaliphilic bacterium at pH 11.0 and 7.0% salinity.

Rise in the pH of an unfrozen solution in ice due to the presence of NaCl and promotion of decomposition of gallic acids owing to a change in the pH.

PubMed

Takenaka, Norimichi; Tanaka, Masayuki; Okitsu, Kenji; Bandow, Hiroshi

2006-09-14

Oxidative decomposition of gallic acid occurs in alkaline solutions but hardly arises in acidic solutions. We have found that the addition of sodium chloride promotes the decomposition of gallic acid caused by freezing even under neutral and acidic conditions. Even at pH 4.5, gallic acid was decomposed by freezing in the presence of NaCl; however, in the absence of NaCl, it was hardly decomposed by freezing at pH lower than 7. Chloride ions are more easily incorporated in ice than sodium ions when the NaCl solution is frozen. The unfrozen solution in ice becomes positively charged, and as a result, protons transfer from the unfrozen solution to the ice. We measured the pH in the unfrozen solution which coexists with single-crystal ice formed from a 5 mmol dm(-3) NaCl solution and determined the pH to be 8.6 at equilibrium with CO(2) of 380 ppm or 11.3 in the absence of CO(2) compared to pH 5.6 in the original solution. From the model calculation performed for gallic acid solution in the presence of 5 mmol dm(-3) NaCl, it can be estimated that the amount of OH(-) transferred from the ice to the solution corresponds to 1.26 x 10(-5) mol dm(-3). The amount of OH(-) transferred is concentrated into the unfrozen solution and affects the pH of the unfrozen solution. Therefore, the pH in an unfrozen gallic acid solution in ice becomes alkaline, and the decomposition of gallic acid proceeds. It is expected that other base-catalyzed reactions in weakly acidic solutions also proceed by freezing in the presence of NaCl without the need for any alkaline reagents.

Effect of pH on the survival of Listeria innocua in calcium ascorbate solutions and on quality of fresh-cut apples.

PubMed

Karaibrahimoglu, Yildiz; Fan, Xuetong; Sapers, Gerald M; Sokorai, Kimberly

2004-04-01

Fresh-cut apple slices were dipped in calcium ascorbate (CaA) solution at pH values ranging from 2.5 to 7.0 to inhibit browning. After treatment, the cut apples were stored at 4 and 10 degrees C for up to 21 days. Color and texture of the apples were determined on days 1, 14, and 21. In a separate experiement, the pH of CaA solution was adjusted with acetic acid to six different pH levels, and the solution was inoculated with Listeria innocua. The survival of the bacterium and the stability of CaA were determined at 0, 20, and 96 h. The cut apples maintained fresh quality when the pH of the CaA solution was above 4.5, but slight discoloration of apple slices dipped in pH 4.5 solution was observed after 14 days at 10 degrees C. At pH 5.0, the CaA dip maintained the quality of the apples at both temperatures for at least 21 days. The L. innocua population was reduced by 4 to 5 log CFU/ml at pH 4.5 after 96 h. At pH 5, the bacterial population in the CaA solution was reduced by approximately 2 log CFU/ml during the same period. The CaA solution was stable at pH 5 for at least 96 h. Reduction of the pH to between 4.5 and 5.0 might reduce the risk of foodborne illness due to consumption of fresh-cut apples treated with a CaA solution contaminated with Listeria.

Biodesulfurization of vanadium-bearing titanomagnetite concentrates and pH control of bioleaching solution

NASA Astrophysics Data System (ADS)

Liu, Xiao-rong; Jiang, Sheng-cai; Liu, Yan-jun; Li, Hui; Wang, Hua-jun

2013-10-01

Vanadium-bearing titanomagnetite concentrates were desulfurized with Acidithiobacillus ferrooxidans ( A. ferrooxidans). The sulfur content of the concentrates was reduced from 0.69wt% to 0.14wt% after bioleaching for 15 d with a 10% pulp density at 30°C. Maintaining a stable pH value during biodesulfurization was critical because of high acid consumption, resulting from a combination of nonoxidative and oxidative dissolution of pyrrhotite in acid solution. It is discovered that the citric acid-disodium hydrogen phosphate buffer of pH 2.0 can control the solution pH value smoothly in the optimal range of 2.0-3.0 for A. ferrooxidans growth. Using the buffer in the volume fraction range of 5.0%-15.0% stimulates A. ferrooxidans growth and improves the biodesulfurization efficiency. Compared with the buffer-free control case, the maximum increase of biodesulfurization rate is 29.7% using a 10.0vol% buffer. Bioleaching provides an alternative process for desulfurization of vanadium-bearing titanomagnetite ores.

Corrosion of dental aluminium bronze in neutral saline and saline lactic acid.

PubMed

Tibballs, J E; Erimescu, Raluca

2006-09-01

To compare the corrosion behaviours of two aluminium bronze, dental casting alloys during a standard immersion test and for immersion in neutral saline. Cast specimens of aluminium bronzes with 1.4 wt% Fe (G) and 4 wt% Fe (N) were subject to progressively longer periods (up to in total 7 days) immersed in 0.1 M saline, 0.1 M lactic acid solutions and examined by scanning electron microscopy with EDX analysis. Immersion in 0.1M neutral saline was for 7 days. In the acidic solution, exposed interdendritic volumes in alloy N corroded completely away in 7 days with dissolution of Ni-enriched precipitate species as well as the copper-rich matrix. Alloy G begins to corrode more slowly but by a similar mechanism. The number density of an Fe-enriched species is insufficient to maintain a continuous galvanic potential to the copper matrix, and dissolution becomes imperceptible. In neutral saline solution, galvanic action alone caused pit-etching, without the dissolution of either precipitate species. The upper limit for the total dissolution of metallic ions in the standard immersion test can be set at 200 microg cm(-2). Aluminium bronze dental alloys can be expected to release both copper and nickel ions into an acidic oral environment.

The relationship between pH and concentrations of antioxidants and vasoconstrictors in local anesthetic solutions.

PubMed

Hondrum, S O; Ezell, J H

1996-01-01

pH affects the efficacy of local anesthetics by determining the percentage of the lipid-soluble base form of the anesthetic available for diffusion and penetration of the nerve sheath. The purpose of this study was to determine the relationship between pH and the concentrations of antioxidant and vasoconstrictor in dental local anesthetic solutions over real-time and after accelerated aging. Several batches of lidocaine and mepivacaine with vasoconstrictors were tested. Results showed that, immediately upon receipt from the manufacturers, three batches were below the USP pH limit (pH 3.3), and two batches contained less than the minimum limit of vasoconstrictors (90%). Real-time tests on batches that were within normal limits revealed that solutions were stable past 4 yr. Accelerated aging tests revealed a strong correlation between a decrease in pH and loss of antioxidants and vasoconstrictors. In conclusion, a quality batch of local anesthetic should remain efficacious long past the manufacturer's stated shelf life; a batch that is less than optimal, or one that is exposed to environmental stresses, will degrade rapidly, and efficacy may be affected by decreases in pH and loss of vasoconstrictor. pH may be an inexpensive, readily available screening test for efficacy of local anesthetics.

The relationship between pH and concentrations of antioxidants and vasoconstrictors in local anesthetic solutions.

PubMed Central

Hondrum, S. O.; Ezell, J. H.

1996-01-01

pH affects the efficacy of local anesthetics by determining the percentage of the lipid-soluble base form of the anesthetic available for diffusion and penetration of the nerve sheath. The purpose of this study was to determine the relationship between pH and the concentrations of antioxidant and vasoconstrictor in dental local anesthetic solutions over real-time and after accelerated aging. Several batches of lidocaine and mepivacaine with vasoconstrictors were tested. Results showed that, immediately upon receipt from the manufacturers, three batches were below the USP pH limit (pH 3.3), and two batches contained less than the minimum limit of vasoconstrictors (90%). Real-time tests on batches that were within normal limits revealed that solutions were stable past 4 yr. Accelerated aging tests revealed a strong correlation between a decrease in pH and loss of antioxidants and vasoconstrictors. In conclusion, a quality batch of local anesthetic should remain efficacious long past the manufacturer's stated shelf life; a batch that is less than optimal, or one that is exposed to environmental stresses, will degrade rapidly, and efficacy may be affected by decreases in pH and loss of vasoconstrictor. pH may be an inexpensive, readily available screening test for efficacy of local anesthetics. PMID:10323112

Usefulness of underwater endoscopic submucosal dissection in saline solution with a monopolar knife for colorectal tumors (with videos).

PubMed

Nagata, Mitsuru

2018-05-01

Generally, colorectal endoscopic submucosal dissection (ESD) is performed with a monopolar knife with CO 2 supply from an endoscope. There are few case reports about underwater ESD (UESD) in saline solution with a bipolar knife. The usefulness and safety of UESD in saline solution with a monopolar knife are unclear. The present study aimed to investigate the usefulness and safety of UESD in saline solution with a monopolar knife for colorectal tumors. This retrospective, observational study on UESD for colorectal tumors included 26 colorectal tumors from 24 patients treated with UESD at our department between October 2015 and February 2017. The characteristics of patients, factors associated with ESD difficulty, treatment results, and variations in blood test data before and after UESD were analyzed. En bloc resection was successful in all lesions without any serious adverse events. The median major diameter of the resected specimens was 30 mm (interquartile range [IQR], 28-35) and of the tumor 22.5 mm (IQR, 17.8-25.3). The median procedure time was 60 minutes (IQR, 45-111) and median speed of dissection 10.4 mm 2 /min (IQR, 6.4-12.2). No cases of perforation occurred. Post-ESD bleeding occurred in only 1 case, and endoscopic hemostasis was achieved. There was no case of electrolyte imbalance requiring treatment after UESD. UESD in saline solution with a monopolar knife for colorectal tumors is useful and safe. UESD has potential advantages that should be further assessed. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Comparative study of buffered 50% glycolic acid (pH 3.0) + 0.5% salicylic acid solution vs Jessner's solution in patients with acne vulgaris.

PubMed

In Jae, Jeong; Dong Ju, Hyun; Dong Hyun, Kim; Yoon, Moon Soo; Lee, Hee Jung

2017-11-21

Superficial chemical peels are frequently used in acne vulgaris treatment. Although glycolic acid (GA) has been widely used in clinical practice, its pH ranges from 0.08-2.75 and thus should be neutralized after application to avoid burns. To evaluate treatment efficacy and safety of chemical peeling using buffered 50% GA (pH 3.0) + 0.5% salicylic acid (SA) solution that does not need to be neutralized in the treatment of acne vulgaris compared to the conventional peeling using Jessner's solution. We performed a prospective, randomized, evaluator-blind, split-face clinical trial. Twenty patients were randomized by assigning one side of each patient's face to receive a 50% GA (pH 3.0) + 0.5% SA peel (GA side) and the other side to receive the Jessner's solution (Jessner's solution side). All patients underwent 2 sessions of treatment spaced 2 weeks apart. Lesion count, acne severity, subjective efficacy assessment, and side effects were evaluated. The total lesion count was significantly reduced for the GA and Jessner's solution sides (P < .001). However, there was no significant difference in the total lesion count, acne severity, or subjective efficacy assessment between the 2 sides (P > .05). The GA side had fewer side effects than the Jessner's solution side. The results of this study suggest that chemical peeling using the 50% GA (pH 3.0) + 0.5% SA solution can be as effective and convenient as the conventional peeling using Jessner's solution in the treatment of acne vulgaris and may show fewer adverse events than the conventional peeling. © 2017 Wiley Periodicals, Inc.

Comparison of the in vitro effects of saline, hypertonic hydroxyethyl starch, hypertonic saline, and two forms of hydroxyethyl starch on whole blood coagulation and platelet function in dogs.

PubMed

Wurlod, Virginie A; Howard, Judith; Francey, Thierry; Schweighauser, Ariane; Adamik, Katja N

2015-01-01

To compare the in vitro effects of hypertonic solutions and colloids to saline on coagulation in dogs. In vitro experimental study. Veterinary teaching hospital. Twenty-one adult dogs. Blood samples were diluted with saline, 7.2% hypertonic saline solution with 6% hydroxyethylstarch with an average molecular weight of 200 kDa and a molar substitution of 0.4 (HH), 7.2% hypertonic saline (HTS), hydroxyethyl starch (HES) 130/0.4 or hydroxyethyl starch 600/0.75 at ratios of 1:22 and 1:9, and with saline and HES at a ratio of 1:3. Whole blood coagulation was analyzed using rotational thromboelastometry (extrinsic thromboelastometry-cloting time (ExTEM-CT), maximal clot firmness (MCF) and clot formation time (CFT) and fibrinogen function TEM-CT (FibTEM-CT) and MCF) and platelet function was analyzed using a platelet function analyzer (closure time, CTPFA ). All parameters measured were impaired by saline dilution. The CTPFA was prolonged by 7.2% hypertonic saline solution with 6% hydroxyethylstarch with an average molecular weight of 200 kDa and a molar substitution of 0.4 (HH) and HTS but not by HES solutions. At clinical dilutions equivalent to those generally administered for shock (saline 1:3, HES 1:9, and hypertonic solutions 1:22), CTPFA was more prolonged by HH and HTS than other solutions but more by saline than HES. No difference was found between the HES solutions or the hypertonic solutions. ExTEM-CFT and MCF were impaired by HH and HTS but only mildly by HES solutions. At clinically relevant dilutions, no difference was found in ExTEM-CFT between HTS and saline or in ExTEM-MCF between HH and saline. No consistent difference was found between the 2 HES solutions but HH impaired ExTEM-CFT and MCF more than HTS. At high dilutions, FibTEM-CT and -MCF and ExTEM-CT were impaired by HES. Hypertonic solutions affect platelet function and whole blood coagulation to a greater extent than saline and HES. At clinically relevant dilutions, only CTPFA was markedly more

Saline as the Sole Contrast Agent for Successful MRI-guided Epidural Injections

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

Deli, Martin, E-mail: martin.deli@web.de; Fritz, Jan, E-mail: jfritz9@jhmi.edu; Mateiescu, Serban, E-mail: mateiescu@microtherapy.de

Purpose. To assess the performance of sterile saline solution as the sole contrast agent for percutaneous magnetic resonance imaging (MRI)-guided epidural injections at 1.5 T. Methods. A retrospective analysis of two different techniques of MRI-guided epidural injections was performed with either gadolinium-enhanced saline solution or sterile saline solution for documentation of the epidural location of the needle tip. T1-weighted spoiled gradient echo (FLASH) images or T2-weighted single-shot turbo spin echo (HASTE) images visualized the test injectants. Methods were compared by technical success rate, image quality, table time, and rate of complications. Results. 105 MRI-guided epidural injections (12 of 105 withmore » gadolinium-enhanced saline solution and 93 of 105 with sterile saline solution) were performed successfully and without complications. Visualization of sterile saline solution and gadolinium-enhanced saline solution was sufficient, good, or excellent in all 105 interventions. For either test injectant, quantitative image analysis demonstrated comparable high contrast-to-noise ratios of test injectants to adjacent body substances with reliable statistical significance levels (p < 0.001). The mean table time was 22 {+-} 9 min in the gadolinium-enhanced saline solution group and 22 {+-} 8 min in the saline solution group (p = 0.75). Conclusion. Sterile saline is suitable as the sole contrast agent for successful and safe percutaneous MRI-guided epidural drug delivery at 1.5 T.« less

Probing pH difference between micellar solution and nanoscale water within common black film by fluorescent dye

NASA Astrophysics Data System (ADS)

Fu, Jingni; Zhang, Luning

2018-03-01

The protonation/deprotonation equilibrium of a fluorescent pH probe (carboxy-seminaphthorhodafluor-1, SNARF-1) within the nanoscale water layer confined in common black films (CBFs) has been studied. We find that SNARF-1 molecules feel a more acidic environment in CBFs than when they are in the bulk micellar solution, using the base/acid peak area ratio of the dye to indicate its microenvironment pH. Three surfactants are used to study the dependence of the pH drop versus charge: cationic (cetyltrimethylammonium bromide, CTAB), anionic (sodium dodecylsulphate, SDS) and nonionic (Triton X-100) species. The decrease of CBFs pH versus the pH of the micellar solution is the following: ΔpH ≈ 1.5 for CTAB (pH: 7.0-9.0), ΔpH ≈ 0.8 for SDS, and ΔpH ≈ 0.4 for Triton X-100. With the addition of electrolyte in CBFs, we observe large decrease the amplitude of the pH anomaly, thus suggesting an electrostatic origin of the pH change at nanoscale environment.

Hypertonic Saline Suppresses NADPH Oxidase-Dependent Neutrophil Extracellular Trap Formation and Promotes Apoptosis.

PubMed

Nadesalingam, Ajantha; Chen, Jacky H K; Farahvash, Armin; Khan, Meraj A

2018-01-01

Tonicity of saline (NaCl) is important in regulating cellular functions and homeostasis. Hypertonic saline is administered to treat many inflammatory diseases, including cystic fibrosis. Excess neutrophil extracellular trap (NET) formation, or NETosis, is associated with many pathological conditions including chronic inflammation. Despite the known therapeutic benefits of hypertonic saline, its underlying mechanisms are not clearly understood. Therefore, we aimed to elucidate the effects of hypertonic saline in modulating NETosis. For this purpose, we purified human neutrophils and induced NETosis using agonists such as diacylglycerol mimetic phorbol myristate acetate (PMA), Gram-negative bacterial cell wall component lipopolysaccharide (LPS), calcium ionophores (A23187 and ionomycin from Streptomyces conglobatus ), and bacteria ( Pseudomonas aeruginosa and Staphylococcus aureus ). We then analyzed neutrophils and NETs using Sytox green assay, immunostaining of NET components and apoptosis markers, confocal microscopy, and pH sensing reagents. This study found that hypertonic NaCl suppresses nicotinamide adenine dinucleotide phosphate oxidase (NADPH2 or NOX2)-dependent NETosis induced by agonists PMA, Escherichia coli LPS (0111:B4 and O128:B12), and P. aeruginosa . Hypertonic saline also suppresses LPS- and PMA- induced reactive oxygen species production. It was determined that supplementing H 2 O 2 reverses the suppressive effect of hypertonic saline on NOX2-dependent NETosis. Many of the aforementioned suppressive effects were observed in the presence of equimolar concentrations of choline chloride and osmolytes (d-mannitol and d-sorbitol). This suggests that the mechanism by which hypertonic saline suppresses NOX2-dependent NETosis is via neutrophil dehydration. Hypertonic NaCl does not significantly alter the intracellular pH of neutrophils. We found that hypertonic NaCl induces apoptosis while suppressing NOX2-dependent NETosis. In contrast, hypertonic

Alteration of chemical behavior of L-ascorbic acid in combination with nickel sulfate at different pH solutions in vitro

PubMed Central

Maniyar, Shaheen A; Jargar, Jameel G; Das, Swastika N; Dhundasi, Salim A; Das, Kusal K

2012-01-01

Objective To evaluate the alteration of chemical behavior of L-ascorbic acid (vitamin C) with metal ion (nickel) at different pH solutions in vitro. Methods Spectra of pure aqueous solution of L-ascorbic acid (E mark) compound and NiSO4 (H2O) (sigma USA) were evaluated by UV visible spectrophotometer. Spectral analysis of L-ascorbic acid and nickel at various pH (2.0, 7.0, 7.4 and 8.6) at room temperature of 29 °C was recorded. In this special analysis, combined solution of L-ascorbic acid and nickel sulfate at different pH was also recorded. Results The result revealed that λmax (peak wavelength of spectra) of L-ascorbic acid at pH 2.0 was 289.0 nm whereas at neutral pH 7.0, λmax was 295.4 nm. In alkaline pH 8.6, λmax was 295.4 nm and at pH 7.4 the λmax of L-ascorbic acid remained the same as 295.4 nm. Nickel solution at acidic pH 2.0 was 394.5 nm, whereas at neutral pH 7.0 and pH 7.4 were the same as 394.5 nm. But at alkaline pH 8.6, λmax value of nickel sulfate became 392.0 nm. The combined solution of L-ascorbic acid and nickel sulfate (6 mg/mL each) at pH 2.0 showed 292.5 nm and 392.5 nm, respectively whereas at pH 7.0, L-ascorbic acid showed 296.5 nm and nickel sulfate showed 391.5 nm. At pH 7.4, L-ascorbic acid showed 297.0 nm and nickel sulfate showed 394.0 nm in the combined solution whereas at pH 8.6 (alkaline) L-ascorbic acid and nickel sulfate were showing 297.0 and 393.5 nm, respectively. Conclusions Results clearly indicate an altered chemical behavior of L-ascorbic acid either alone or in combination with nickel sulfate in vitro at different pH. Perhaps oxidation of L-ascorbic acid to L-dehydro ascorbic acid via the free radical (HSc*) generation from the reaction of H2ASc + Ni (II) is the cause of such alteration of λmax value of L-ascorbic acid in the presence of metal nickel. PMID:23569901

Calorimetric and Diffractometric Evidence for the Sequential Crystallization of Buffer Components and the Consequential pH Swing in Frozen Solutions

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

Sundaramurthi, Prakash; Shalaev, Evgenyi; Suryanarayanan, Raj

2010-06-22

Sequential crystallization of succinate buffer components in the frozen solution has been studied by differential scanning calorimetry and X-ray diffractometry (both laboratory and synchrotron sources). The consequential pH shifts were monitored using a low-temperature electrode. When a solution buffered to pH < pK{sub a2} was cooled from room temperature (RT), the freeze-concentrate pH first increased and then decreased. This was attributed to the sequential crystallization of succinic acid, monosodium succinate, and finally disodium succinate. When buffered to pH > pK{sub a2}, the freeze-concentrate pH first decreased and then increased due to the sequential crystallization of the basic (disodium succinate) followedmore » by the acidic (monosodium succinate and succinic acid) buffer components. XRD provided direct evidence of the crystallization events in the frozen buffer solutions, including the formation of disodium succinate hexahydrate [Na{sub 2}(CH{sub 2}COO){sub 2} {center_dot} 6H{sub 2}O]. When the frozen solution was warmed in a differential scanning calorimeter, multiple endotherms attributable to the melting of buffer components and ice were observed. When the frozen solutions were dried under reduced pressure, ice sublimation was followed by dehydration of the crystalline hexahydrate to a poorly crystalline anhydrate. However, crystalline succinic acid and monosodium succinate were retained in the final lyophiles. The pH and the buffer salt concentration of the prelyo solution influenced the crystalline salt content in the final lyophile. The direction and magnitude of the pH shift in the frozen solution depended on both the initial pH and the buffer concentration. In light of the pH-sensitive nature of a significant fraction of pharmaceuticals (especially proteins), extreme care is needed in both the buffer selection and its concentration.« less

Stochastic Modeling of Soil Salinity

NASA Astrophysics Data System (ADS)

Suweis, Samir; Rinaldo, Andrea; van der Zee, Sjoerd E. A. T. M.; Maritan, Amos; Porporato, Amilcare

2010-05-01

Large areas of cultivated land worldwide are affected by soil salinity. Estimates report that 10% of arable land in over 100 countries, and nine million km2 are salt affected, especially in arid and semi-arid regions. High salinity causes both ion specific and osmotic stress effects, with important consequences for plant production and quality. Salt accumulation in the root zone may be due to natural factors (primary salinization) or due to irrigation (secondary salinization). Simple (e.g., vertically averaged over the soil depth) coupled soil moisture and salt balance equations have been used in the past. Despite their approximations, these models have the advantage of parsimony, thus allowing a direct analysis of the interplay of the main processes. They also provide the ideal starting point to include external, random hydro-climatic fluctuations in the analysis of long-term salinization trends. We propose a minimalist stochastic model of primary soil salinity, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The long term probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equation to a stochastic differential equation driven by multiplicative Poisson noise. The novel analytical solutions provide insight on the interplay of the main soil, plant and climate parameters responsible for long-term soil salinization. In fact, soil salinity statistics are obtained as a function of climate, soil and vegetation parameters. These, in turn, can be combined with soil moisture statistics to obtain a full characterization of soil salt concentrations and the ensuing risk of primary salinization. In particular, the solutions show the existence of two quite distinct regimes, the first one where the mean salt mass remains nearly constant with increasing rainfall frequency, and the

Stability study of docetaxel solution (0.9%, saline) using Non-PVC and PVC tubes for intravenous administration.

PubMed

Park, Kang Hoon; Chung, Dong June

2015-01-01

Di-2-ethylhexyl phthalate (DEHP) are added to poly(vinyl chloride)(PVC) infusion tubes as a plasticizer to ensure tube flexibility. In addition to previously reported disadvantages of DEHP, released DEHP molecules from PVC tubes can easily interact with surfactants in anticancer drug solutions (i.e., polysorbate 80 for Taxotere®-Inj) and reduce the solubility of docetaxel in aqueous solution during anticancer drug administration. In this study, we investigated the in vitro stability of docetaxel in a 0.9% saline solution under an intravenous administration condition using a PVC tube (high DEHP content) and non-PVC infused tube. The docetaxel solution circulating through the non-PVC tube had better solution stability than through the PVC tube(high DEHP content).

PH Sensitive Polymers for Improving Reservoir Sweep and Conformance Control in Chemical Flooring

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

Mukul Sharma; Steven Bryant; Chun Huh

viscoelastic behavior as functions of pH; shear rate; polymer concentration; salinity, including divalent ion effects; polymer molecular weight; and degree of hydrolysis. A comprehensive rheological model was developed for HPAM solution rheology in terms of: shear rate; pH; polymer concentration; and salinity, so that the spatial and temporal changes in viscosity during the polymer flow in the reservoir can be accurately modeled. A series of acid coreflood experiments were conducted to understand the geochemical reactions relevant for both the near-wellbore injection profile control and for conformance control applications. These experiments showed that the use hydrochloric acid as a pre-flush is not viable because of the high reaction rate with the rock. The use of citric acid as a pre-flush was found to be quite effective. This weak acid has a slow rate of reaction with the rock and can buffer the pH to below 3.5 for extended periods of time. With the citric acid pre-flush the polymer could be efficiently propagated through the core in a low pH environment i.e. at a low viscosity. The transport of various HPAM solutions was studied in sandstones, in terms of permeability reduction, mobility reduction, adsorption and inaccessible pore volume with different process variables: injection pH, polymer concentration, polymer molecular weight, salinity, degree of hydrolysis, and flow rate. Measurements of polymer effluent profiles and tracer tests show that the polymer retention increases at the lower pH. A new simulation capability to model the deep-penetrating mobility control or conformance control using pH-sensitive polymer was developed. The core flood acid injection experiments were history matched to estimate geochemical reaction rates. Preliminary scale-up simulations employing linear and radial geometry floods in 2-layer reservoir models were conducted. It is clearly shown that the injection rate of pH-sensitive polymer solutions can be significantly increased by injecting

Prevention of Oral Candidiasis After Free Flap Surgery: Role of 3% Sodium Bicarbonate Saline in Oral Care.

PubMed

Yang, Yue; Zhang, Fang; Lyu, Xin; Yan, Zhimin; Hua, Hong; Peng, Xin

2017-03-01

Relevant reports about oral candidiasis status and prevention measures after free flap surgery for the oral and maxillofacial region are limited. The present study explored oral candidiasis status after free flap surgery and its prevention through a prospective comparative study. One hundred four patients were randomized to a control group (n = 54) and an experimental group (n = 50). Compared with the control group, the experimental group was provided an additional 3% sodium bicarbonate saline solution for oral care after free flap surgery. The incidence of oral candidiasis was evaluated by objective examination (saliva culture and salivary pH measurement) and subjective evaluation (clinical signs of oral candidiasis) at admission and from postoperative days 1 to 14. The salivary pH values of the 2 groups were lower than the normal salivary pH, and postoperative salivary pH values were always lower than the active range of oral lysozymes in the control group. The salivary pH values of the experimental group were higher than those of the control group from postoperative days 6 to 14 (P < .05). The incidence of oral candidiasis was 13.0% in the control group, which was higher than that in the experimental group (2.0%; P < .05). In addition, advanced age, use of a free flap for the simultaneous repair of intraoral and paraoral defects, and a combination of 2 antibiotic types were risk factors for oral candidiasis. Oral candidiasis was common in patients after free flap reconstruction surgery, and the use of 3% sodium bicarbonate saline solution for oral care effectively prevented it. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Study of pH Stability of R-Salbutamol Sulfate Aerosol Solution and Its Antiasthmatic Effects in Guinea Pigs.

PubMed

Liu, Qing; Li, Qingrui; Han, Ting; Hu, Tingting; Zhang, Xuemei; Hu, Junhua; Hu, Hui; Tan, Wen

2017-09-01

Currently, all commercial available nebulized salbutamol in China is in its racemic form. It is known that only R-salbutamol (eutomer) has therapeutic effects, while S-salbutamol (distomer) may exacerbate asthma after chronic use. Therefore, it is an unmet clinical need to develop R-salbutamol as a nebulized product that is more convenient for young and old patients. In our study, a stable aerosol solution of R-salbutamol sulfate was established, and its antiasthmatic effects were confirmed. The decomposition rate and racemization effect of the R-salbutamol sulfate solution were evaluated over a pH range from 1 to 10 (except pH=7, 8) at 60°C. The aerodynamic particle size of the R-salbutamol sulfate solution and commercial RS-salbutamol sulfate solution were both tested in vitro by Next-Generation Impactor (NGI) in 5°C. Laser diffractometer was used to characterize the droplet-size distribution (DSD) of both solutions. We next conducted an in vivo animal study to document the antiasthmatic effect of R-salbutamol aerosol sulfate solution and determine the relationship to RS-salbutamol. The results showed that the R-salbutamol sulfate solution was more stable at pH 6. In vitro comparison studies indicated that there was no distribution difference between R-salbutamol sulfate solution and the commercial RS-salbutamol solution. The animal results showed that R-salbutamol was more potent than RS-salbutamol against the same dose of histamine challenge. Unlike commercial RS-salbutamol, which was acidified to a pH of 3.5 to extend bench life but may cause bronchoconstriction in asthmatic patients, the neutralized R-salbutamol solution was more suitable for clinic use.

Solutions Network Formulation Report. Integrating Salinity Measurements from Aquarius into the Harmful Algal Blooms Observing System

NASA Technical Reports Server (NTRS)

Anderson, Daniel; Lewis, David; Hilbert, Kent

2007-01-01

This Candidate Solution suggests the use of Aquarius sea surface salinity measurements to improve the NOAA/NCDDC (National Oceanic and Atmospheric Administration s National Coastal Data Development Center) HABSOS (Harmful Algal Blooms Observing System) DST (decision support tool) by enhancing development and movement forecasts of HAB events as well as potential species identification. In the proposed configuration, recurring salinity measurements from the Aquarius mission would augment HABSOS sea surface temperature and in situ ocean current measurements. Thermohaline circulation observations combined with in situ measurements increase the precision of HAB event movement forecasting. These forecasts allow coastal managers and public health officials to make more accurate and timely warnings to the public and to better direct science teams to event sites for collection and further measurements.

Effect of Aging Temperature on Corrosion Behavior of Sintered 17-4 PH Stainless Steel in Dilute Sulfuric Acid Solution

NASA Astrophysics Data System (ADS)

Szewczyk-Nykiel, Aneta; Kazior, Jan

2017-07-01

The general corrosion behavior of sintered 17-4 PH stainless steel processed under different processing conditions in dilute sulfuric acid solution at 25 °C was studied by open-circuit potential measurement and potentiodynamic polarization technique. The corrosion resistance was evaluated based on electrochemical parameters, such as polarization resistance, corrosion potential, corrosion current density as well as corrosion rate. The results showed that the precipitation-hardening treatment could significantly improve the corrosion resistance of the sintered 17-4 PH stainless steel in studied environment. As far as the influence of aging temperature on corrosion behavior of the sintered 17-4 PH stainless steel is concerned, polarization resistance and corrosion rate are reduced with increasing aging temperature from 480 up to 500 °C regardless of the temperature of solution treatment. It can be concluded that the highest corrosion resistance in 0.5 M H2SO4 solution exhibits 17-4 PH after solution treatment at 1040 °C followed by aging at 480 °C.

Low-temperature solution processing of palladium/palladium oxide films and their pH sensing performance.

PubMed

Qin, Yiheng; Alam, Arif U; Pan, Si; Howlader, Matiar M R; Ghosh, Raja; Selvaganapathy, P Ravi; Wu, Yiliang; Deen, M Jamal

2016-01-01

Highly sensitive, easy-to-fabricate, and low-cost pH sensors with small dimensions are required to monitor human bodily fluids, drinking water quality and chemical/biological processes. In this study, a low-temperature, solution-based process is developed to prepare palladium/palladium oxide (Pd/PdO) thin films for pH sensing. A precursor solution for Pd is spin coated onto pre-cleaned glass substrates and annealed at low temperature to generate Pd and PdO. The percentages of PdO at the surface and in the bulk of the electrodes are correlated to their sensing performance, which was studied by using the X-ray photoelectron spectroscope. Large amounts of PdO introduced by prolonged annealing improve the electrode's sensitivity and long-term stability. Atomic force microscopy study showed that the low-temperature annealing results in a smooth electrode surface, which contributes to a fast response. Nano-voids at the electrode surfaces were observed by scanning electron microscope, indicating a reason for the long-term degradation of the pH sensitivity. Using the optimized annealing parameters of 200°C for 48 h, a linear pH response with sensitivity of 64.71±0.56 mV/pH is obtained for pH between 2 and 12. These electrodes show a response time shorter than 18 s, hysteresis less than 8 mV and stability over 60 days. High reproducibility in the sensing performance is achieved. This low-temperature solution-processed sensing electrode shows the potential for the development of pH sensing systems on flexible substrates over a large area at low cost without using vacuum equipment. Copyright © 2015 Elsevier B.V. All rights reserved.

Structures of Cu surfaces developing in benzotriazole solutions: Effect of pH

NASA Astrophysics Data System (ADS)

Kondoh, Eiichi; Kawakami, Tatsuya; Watanabe, Mitsuhiro; Jin, Linhua; Hamada, Satomi; Shima, Shohei; Hiyama, Hirokuni

2017-07-01

The effect of pH on layer formation onto clean Cu surfaces in benzotriazole (BTA) aqueous solutions was studied by in situ spectroscopic ellipsometry. The effect of H2O2 addition was also investigated. Time changes in the ellipsometric parameters Ψ and Δ, which correspond to the structural changes of the layers on Cu, were discussed. In acidic solutions, a BTA or a Cu-BTA complex layer grows directly on Cu. The out-diffusion of Cu is suppressed at the Cu layer interface. When H2O2 was mixed, the Cu surface is eroded in acidic solutions. In alkaline solutions, the BTA layer grows on the oxidized Cu layer, or no growth occurs, depending on the composition of the solutions. In neutral solutions, the Cu-BTA complex layer forms on Cu, and the uncovered part is oxidized in the presence of H2O2.

Evaluation of effects of pH and ionic strength on colloidal stability of IgG solutions by PEG-induced liquid-liquid phase separation.

PubMed

Thompson, Ronald W; Latypov, Ramil F; Wang, Ying; Lomakin, Aleksey; Meyer, Julie A; Vunnum, Suresh; Benedek, George B

2016-11-14

Colloidal stability of IgG antibody solutions is important for pharmaceutical and medicinal applications. Solution pH and ionic strength are two key factors that affect the colloidal stability of protein solutions. In this work, we use a method based on the PEG-induced liquid-liquid phase separation to examine the effects of pH and ionic strength on the colloidal stability of IgG solutions. We found that at high ionic strength (≥0.25M), the colloidal stability of most of our IgGs is insensitive to pH, and at low ionic strength (≤0.15M), all IgG solutions are much more stable at pH 5 than at pH 7. In addition, the PEG-induced depletion force is less efficient in causing phase separation at pH 5 than at pH 7. In contrast to the native inter-protein interaction of IgGs, the effect of depletion force on phase separation of the antibody solutions is insensitive to ionic strength. Our results suggest that the long-range electrostatic inter-protein repulsion at low ionic strength stabilizes the IgG solutions at low pH. At high ionic strength, the short-range electrostatic interactions do not make a significant contribution to the colloidal stability for most IgGs with a few exceptions. The weaker effect of depletion force at lower pH indicates a reduction of protein concentration in the condensed phase. This work advances our basic understanding of the colloidal stability of IgG solutions and also introduces a practical approach to measuring protein colloidal stability under various solution conditions.

A renaissance of soaps? - How to make clear and stable solutions at neutral pH and room temperature.

PubMed

Wolfrum, Stefan; Marcus, Julien; Touraud, Didier; Kunz, Werner

2016-10-01

Soaps are the oldest and perhaps most natural surfactants. However, they lost much of their importance since "technical surfactants", usually based on sulfates or sulfonates, have been developed over the last fifty years. Indeed, soaps are pH- and salt-sensitive and they are irritant, especially to the eyes. In food emulsions, although authorized, they have a bad taste, and long-chain saturated soaps have a high Krafft temperature. We believe that most or perhaps all of these problems can be solved with modern formulation approaches. We start this paper with a short overview of our present knowledge of soaps and soap formulations. Then we focus on the problem of the lacking soap solubility at neutral pH values. For example, it is well known that with the food emulsifier sodium oleate (NaOl), clear and stable aqueous solutions can only be obtained at pH values higher than 10. A decrease in the pH value leads to turbid and unstable solutions. This effect is not compatible with the formulation of aqueous stable and drinkable formulations with neutral or even acidic pH values. However, the pH value/phase behavior of aqueous soap solutions can be altered by the addition of other surfactants. Such a surfactant can be Rebaudioside A (RebA), a steviol glycoside from the plant Stevia rebaudiana which is used as a natural food sweetener. In a recent paper, we showed the influence of RebA on the apKa value of sodium oleate in a beverage microemulsion and on its clearing temperature. In the present paper, we report on the effect of the edible bio-surfactant RebA, on the macroscopic and microscopic phase behavior of simple aqueous sodium oleate solutions at varying pH values. The macroscopic phase behavior is investigated by visual observation and turbidity measurements. The microscopic phase behavior is analyzed by acid-base titration curves, phase-contrast and electron microscopy. It turned out that even at neutral pH, aqueous NaOl/RebA solutions can be completely clear and

Groundwater-saline lakes interaction - The contribution of saline groundwater circulation to solute budget of saline lakes: a lesson from the Dead Sea

NASA Astrophysics Data System (ADS)

Kiro, Yael; Weinstein, Yishai; Starinsky, Abraham; Yechieli, Yoseph

2013-04-01

Saline lakes act as base level for both surface water and groundwater. Thus, a change in lake levels is expected to result in changes in the hydrogeological system in its vicinity, exhibited in groundwater levels, location of the fresh-saline water interface, sub-lacustrine groundwater discharge (SGD) and saline water circulation. All these processes were observed in the declining Dead Sea system, whose water level dropped by ~35 meters in the last 50 years. This work focuses mainly on the effect of circulation of Dead Sea water in the aquifer, which continues even in this very rapid base level drop. In general, seawater circulation in coastal aquifers is now recognized as a major process affecting trace element mass balances in coastal areas. Estimates of submarine groundwater discharge (SGD) vary over several orders of magnitude (1-1000000 m3/yr per meter shoreline). These estimates are sensitive to fresh-saline SGD ratios and to the temporal and spatial scales of the circulation. The Dead Sea system is an excellent natural field lab for studying seawater-groundwater interaction and large-scale circulation due to the absence of tides and to the minor role played by waves. During Dead Sea water circulation in the aquifer several geochemical reactions occur, ranging from short-term adsorption-desorption reactions and up to long-term precipitation and dissolution reactions. These processes affect the trace element distribution in the saline groundwater. Barite and celestine, which are supersaturated in the lake water, precipitate during circulation in the aquifer, reducing barium (from 5 to 1.5 mg/L), strontium (from 350 to 300 mg/L) and the long-lived 226Ra (from 145 to 60 dpm/L) in the saline groundwater. Redox-controlled reactions cause a decrease in uranium from 2.4 to 0.1 μg/L, and an increase in iron from 1 to 13 mg/L. 228Ra (t1/2=5.75 yr) activity in the Dead Sea is ~1 dpm/L and increase gradually as the saline water flows further inland until reaching

Investigation of the adsorption mechanism of a peptide in reversed phase liquid chromatography, from pH controlled and uncontrolled solutions

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

Gritti, Fabrice; Guiochon, Georges A

2009-01-01

The single-component equilibrium adsorption of the tripeptide Leucyl-Leucyl-Leucine (LLL) on a high-efficiency Jupiter Proteo column (C{sub 12}) was investigated experimentally and modeled theoretically. The experimental equilibrium isotherms of LLL for adsorption on a C{sub 12} packing material from an aqueous solution of methanol (48%) and trifluoroacetic acid (0.1%) were measured by frontal analysis (FA). The FA measurements were done with two solutions, one in which the pH was controlled, the other in which it was not. Two solutions of LLL in the mobile phase were prepared (4.3 and 5.4 g/L) and their pH measured (2.94 and 2.88), respectively. The firstmore » solution was titrated with TFA to match the pH of the mobile phase (2.03), so its pH was controlled. The pH of the other solution was left uncontrolled. In both cases the isotherms could be modeled by a bi-Langmuir equation, a choice consistent with the bimodal affinity energy distribution (AED) obtained for LLL. The isotherm parameters derived from the inverse method (IM) of isotherm determination under controlled pH conditions (by fitting calculated profiles to experimental breakthrough profiles) are in a good agreement with those derived from the FA data. Under uncontrolled pH conditions, the application of IM suggests the coexistence of two different adsorption mechanisms. According to the isotherm parameters found by these three methods (FA, AED and IM), the C{sub 12}-bonded silica can adsorb around 500 and 70 g/L of LLL under controlled and uncontrolled pH conditions, respectively. The adsorption of LLL on the C{sub 12} material strongly depends on the pH of the mobile phase and on the quantity of TFA added, which plays the role of an ion-pairing agent.« less

Modeling the effects of different irrigation water salinity on soil water movement, uptake and multicomponent solute transport

NASA Astrophysics Data System (ADS)

Lekakis, E. H.; Antonopoulos, V. Z.

2015-11-01

Simulation models can be important tools for analyzing and managing irrigation, soil salinization or crop production problems. In this study a mathematical model that describes the water movement and mass transport of individual ions (Ca2+, Mg2+ and Na+) and overall soil salinity by means of the soil solution electrical conductivity, is used. The mass transport equations of Ca2+, Mg2+ and Na+ have been incorporated as part of the integrated model WANISIM and the soil salinity was computed as the sum of individual ions. The model was calibrated and validated against field data, collected during a three year experiment in plots of maize, irrigated with three different irrigation water qualities, at Thessaloniki area in Northern Greece. The model was also used to evaluate salinization and sodification hazards by the use of irrigation water with increasing electrical conductivity of 0.8, 3.2 and 6.4 dS m-1, while maintaining a ratio of Ca2+:Mg2+:Na+ equal to 3:3:2. The qualitative and quantitative procedures for results evaluation showed that there was good agreement between the simulated and measured values of the water content, overall salinity and the concentration of individual soluble cations, at two soil layers (0-35 and 35-75 cm). Nutrient uptake was also taken into account. Locally available irrigation water (ECiw = 0.8 dS m-1) did not cause soil salinization or sodification. On the other hand, irrigation water with ECiw equal to 3.2 and 6.4 dS m-1 caused severe soil salinization, but not sodification. The rainfall water during the winter seasons was not sufficient to leach salts below the soil profile of 110 cm. The modified version of model WANISIM is able to predict the effects of irrigation with saline waters on soil and plant growth and it is suitable for irrigation management in areas with scarce and low quality water resources.

Gravity-driven pH adjustment for site-specific protein pKa measurement by solution-state NMR

NASA Astrophysics Data System (ADS)

Li, Wei

2017-12-01

To automate pH adjustment in site-specific protein pKa measurement by solution-state NMR, I present a funnel with two caps for the standard 5 mm NMR tube. The novelty of this simple-to-build and inexpensive apparatus is that it allows automatic gravity-driven pH adjustment within the magnet, and consequently results in a fully automated NMR-monitored pH titration without any hardware modification on the NMR spectrometer.

Protective effect of TiF(4) solutions with different concentrations and pH on development of erosion-like lesions.

PubMed

Hove, L H; Holme, B; Stenhagen, K R; Tveit, A B

2011-01-01

To evaluate how concentration and pH of TiF(4) influence the erosion-protective effect. Specimens were treated with a TiF(4) solution: (1) 0.5 M F, pH 1.2, (2) 0.05 M F, pH 2.1, (3) 0.5 M F, pH 2.1, or (4) 0.05 M F, pH 1.2; then, they were exposed to HCl. After 2 min, the proportions of the area covered with the coating were 93, 71, 17 and 0% in groups 1-4. When present, the coating seemed to protect the surface. After 6 min, a coating could only be seen in group 1 (43%). Reducing the concentration of TiF(4) and increasing the pH of the solution decreased the protective effect. 2011 S. Karger AG, Basel.

Influence of pH on the physical and electromagnetic properties of Mg–Mn ferrite synthesized by a solution combustion method

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

Lwin, Nilar, E-mail: nilarlwin111@gmail.com; School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang; Othman, Radzali, E-mail: radzali@utem.edu.my

The synthesis of nano-crystalline Mg–Mn ferrites by a solution combustion method using citric acid and ammonia was investigated by varying the pH of the precursor solution, which played an important role in controlling the morphology of the synthesized powders. The phase formation, microstructure and electromagnetic properties were studied using X-ray diffraction, scanning electron microscopy, impedance analyzer and vibrating sample magnetometer. Single phase pure spinel Mg–Mn ferrite powders were obtained for all the samples at different pH (< 1, 3, 5, 7, 9). The results showed that an increase of pH improves the crystallinity of the Mg–Mn ferrite nanoparticles. The averagemore » grain size of sintered samples was found to decrease from 2 μm to 0.5 μm with increasing pH values from pH < 1 to pH 9, respectively. The dielectric constant of the samples with different pH is in the range of 7–12 from frequencies of 1 MHz to 1 GHz. The highest saturation magnetization (30.04 emu/g) was obtained for the sample with pH < 1. - Highlights: • Mg–Mn ferrites were synthesized by a solution combustion method with different pH. • Auto-combustion process resulted in the formation of single phase spinel ferrite. • An increase of pH improves the crystallinity of the Mg–Mn ferrite nanoparticles. • pH variation has influence on phase formation and morphology of the ferrite.« less

Characterisation and deployment of an immobilised pH sensor spot towards surface ocean pH measurements.

PubMed

Clarke, Jennifer S; Achterberg, Eric P; Rérolle, Victoire M C; Abi Kaed Bey, Samer; Floquet, Cedric F A; Mowlem, Matthew C

2015-10-15

The oceans are a major sink for anthropogenic atmospheric carbon dioxide, and the uptake causes changes to the marine carbonate system and has wide ranging effects on flora and fauna. It is crucial to develop analytical systems that allow us to follow the increase in oceanic pCO2 and corresponding reduction in pH. Miniaturised sensor systems using immobilised fluorescence indicator spots are attractive for this purpose because of their simple design and low power requirements. The technology is increasingly used for oceanic dissolved oxygen measurements. We present a detailed method on the use of immobilised fluorescence indicator spots to determine pH in ocean waters across the pH range 7.6-8.2. We characterised temperature (-0.046 pH/°C from 5 to 25 °C) and salinity dependences (-0.01 pH/psu over 5-35), and performed a preliminary investigation into the influence of chlorophyll on the pH measurement. The apparent pKa of the sensor spots was 6.93 at 20 °C. A drift of 0.00014 R (ca. 0.0004 pH, at 25 °C, salinity 35) was observed over a 3 day period in a laboratory based drift experiment. We achieved a precision of 0.0074 pH units, and observed a drift of 0.06 pH units during a test deployment of 5 week duration in the Southern Ocean as an underway surface ocean sensor, which was corrected for using certified reference materials. The temperature and salinity dependences were accounted for with the algorithm, R=0.00034-0.17·pH+0.15·S(2)+0.0067·T-0.0084·S·1.075. This study provides a first step towards a pH optode system suitable for autonomous deployment. The use of a short duration low power illumination (LED current 0.2 mA, 5 μs illumination time) improved the lifetime and precision of the spot. Further improvements to the pH indicator spot operations include regular application of certified reference materials for drift correction and cross-calibration against a spectrophotometric pH system. Desirable future developments should involve novel

Baclofen Solution for Low-Volume Therapeutic Delivery.

PubMed

Meythaler, Jay M; Peduzzi, Jean D

2017-06-01

Baclofen is a zwitterion molecule where increased ions in the excipient increase the solubility. We developed baclofen in a stable solution similar to cerebrospinal fluid (CSF) without bicarbonate and proteins to improve the solubility of the baclofen and to reduce the potential toxicity to the central nervous system (CNS) and subarachnoid space. The objective is to develop a solution of baclofen wherein baclofen is solubilized in a multivalent physiological ion solution such as artificial cerebrospinal fluid (aCSF) at a concentration from 2 mg/cc to 10 mg/cc. First, to determine the solubility of Baclofen in aCSF, solubility was determined at six different pH levels at 37°C, by the addition of aCSF to a known amount of Baclofen. The final concentrations were confirmed by high performance liquid chromatography (HPLC) analysis. Second, the stability of Baclofen at 4 mg/cc investigated in a test manufacturing batch utilizing standard methods of production of 1500 20 cc vials inverted for 18 months at 25°C at 60% humidity. The stability and purity of the baclofen was verified at 18 months by HPLC analysis. Baclofen was initially soluble between pH of 6-8 above 7 mg/cc but fell back to 6.3-5.8 mg/cc level with time. Baclofen produced in vials with inversion were noted to be stable at 4 mg/cc at 18 months with less than 2% breakdown of the baclofen in solution. Baclofen is much more soluble in artificial CSF than normal saline. The artificial CSF may also be less toxic to the subarachnoid space than saline. © 2016 International Neuromodulation Society.

Bulk Moisture and Salinity Sensor

NASA Technical Reports Server (NTRS)

Nurge, Mark; Monje, Oscar; Prenger, Jessica; Catechis, John

2013-01-01

Measurement and feedback control of nutrient solutions in plant root zones is critical to the development of healthy plants in both terrestrial and reduced-gravity environments. In addition to the water content, the amount of fertilizer in the nutrient solution is important to plant health. This typically requires a separate set of sensors to accomplish. A combination bulk moisture and salinity sensor has been designed, built, and tested with different nutrient solutions in several substrates. The substrates include glass beads, a clay-like substrate, and a nutrient-enriched substrate with the presence of plant roots. By measuring two key parameters, the sensor is able to monitor both the volumetric water content and salinity of the nutrient solution in bulk media. Many commercially available moisture sensors are point sensors, making localized measurements over a small volume at the point of insertion. Consequently, they are more prone to suffer from interferences with air bubbles, contact area of media, and root growth. This makes it difficult to get an accurate representation of true moisture content and distribution in the bulk media. Additionally, a network of point sensors is required, increasing the cabling, data acquisition, and calibration requirements. measure the dielectric properties of a material in the annular space of the vessel. Because the pore water in the media often has high salinity, a method to measure the media moisture content and salinity simultaneously was devised. Characterization of the frequency response for capacitance and conductance across the electrodes was completed for 2-mm glass bead media, 1- to 2-mm Turface (a clay like media), and 1- to 2-mm fertilized Turface with the presence of root mass. These measurements were then used to find empirical relationships among capacitance (C), the dissipation factor (D), the volumetric water content, and the pore water salinity.

The distribution and origins of extremely acidic saline groundwaters in the south of Western Australia - Groundwater and digital mapping datasets provide new insights

NASA Astrophysics Data System (ADS)

Lillicrap, Adam M.; Biermann, Vera; George, Richard J.; Gray, David J.; Oldham, Carolyn E.

2018-01-01

Some of the largest extents of naturally occurring acidic waters are found across southern Australia. The origins of these systems remain poorly understood with many hypotheses for their genesis. Australian government agency groundwater datasets and mapping data (vegetation, geology, regolith and soils) for south-western Australia, unavailable to previous researchers, were statistically analysed to better understand the origins of acidic groundwater and guide additional fieldwork to study the origins of acidic saline groundwater. The groundwater data showed a distinct bimodal distribution in pH; the 'acid' population had a median pH of 3.5 and the larger 'non-acid' population had a median pH of 6.6. Acidic groundwater became progressively more common further from the coast towards the drier internally drained regions. Acidic groundwater was mostly confined to the lower slopes and valley floors with localised controls on distribution. Paradoxically, subsoil alkalinity within the internally drained inland regions had the strongest correlation with acidic groundwater (r2 = 0.85). Vegetation was also a strong predictor of acidic groundwater. Acidic groundwater had the highest occurrence under Eucalyptus woodlands and shrublands that grew on alkaline calcareous soils. Pre-clearing soil data in areas with acidic saline groundwater showed that the upper 1 m of the unsaturated zone had a pH around 8 while the pH at depths greater than 5 m decreased to <4. Based on the observations it is proposed that biogenic formation of calcareous soils occurs in the upper 1 m of the profile, calcium is sourced from the deeper profile where the root biota exchanges calcium for hydrogen ions to maintain charge balance. Iron is mobilised from the upper soil profile and concentrates lower in the profile at depths >1.5 m. There, the iron is reduced around roots and the alkalinity generated by microbial iron reduction is removed by biogenic calcification processes. The iron moves in solution

Spectrophotometric Calibration of pH Electrodes in Seawater Using Purified m-Cresol Purple

PubMed Central

2012-01-01

This work examines the use of purified meta-cresol purple (mCP) for direct spectrophotometric calibration of glass pH electrodes in seawater. The procedures used in this investigation allow for simple, inexpensive electrode calibrations over salinities of 20–40 and temperatures of 278.15–308.15 K without preparation of synthetic Tris seawater buffers. The optimal pH range is ∼7.0–8.1. Spectrophotometric calibrations enable straightforward, quantitative distinctions between Nernstian and non-Nernstian electrode behavior. For the electrodes examined in this study, both types of behavior were observed. Furthermore, calibrations performed in natural seawater allow direct determination of the influence of salinity on electrode performance. The procedures developed in this study account for salinity-induced variations in liquid junction potentials that, if not taken into account, would create pH inconsistencies of 0.028 over a 10-unit change in salinity. Spectrophotometric calibration can also be used to expeditiously determine the intercept potential (i.e., the potential corresponding to pH 0) of an electrode that has reliably demonstrated Nernstian behavior. Titrations to ascertain Nernstian behavior and salinity effects can be undertaken relatively infrequently (∼weekly to monthly). One-point determinations of intercept potential should be undertaken frequently (∼daily) to monitor for stable electrode behavior and ensure accurate potentiometric pH determinations. PMID:22463815

Iridium oxide pH sensor for biomedical applications. Case urea-urease in real urine samples.

PubMed

Prats-Alfonso, Elisabet; Abad, Llibertat; Casañ-Pastor, Nieves; Gonzalo-Ruiz, Javier; Baldrich, Eva

2013-01-15

This work demonstrates the implementation of iridium oxide films (IROF) grown on silicon-based thin-film platinum microelectrodes, their utilization as a pH sensor, and their successful formatting into a urea pH sensor. In this context, Pt electrodes were fabricated on Silicon by using standard photolithography and lift-off procedures and IROF thin films were growth by a dynamic oxidation electrodeposition method (AEIROF). The AEIROF pH sensor reported showed a super-Nerstian (72.9±0.9mV/pH) response between pH 3 and 11, with residual standard deviation of both repeatability and reproducibility below 5%, and resolution of 0.03 pH units. For their application as urea pH sensors, AEIROF electrodes were reversibly modified with urease-coated magnetic microparticles (MP) using a magnet. The urea pH sensor provided fast detection of urea between 78μM and 20mM in saline solution, in sample volumes of just 50μL. The applicability to urea determination in real urine samples is discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Development of a pH sensor using nanoporous nanostructures of NiO.

PubMed

Ibupoto, Z H; Khun, K; Willander, M

2014-09-01

Glass is the conventional material used in pH electrodes to monitor pH in various applications. However, the glass-based pH electrode has some limitations for particular applications. The glass sensor is limited in the use of in vivo biomedical, clinical or food applications because of the brittleness of glass, its large size, the difficulty in measuring small volumes and the absence of deformation (inflexibility). Nanostructure-based pH sensors are very sensitive, reliable, fast and applicable towards in vivo measurements. In this study, nanoporous NiO nanostructures are synthesized on a gold-coated glass substrate by a hydrothermal route using poly(vinyl alcohol) (PVA) as a stabilizer. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were used for the morphological and crystalline studies. The grown NiO nanostructures are uniform and dense, and they possess good crystallinity. A pH sensor based on these NiO nanostructures was developed by testing the different pH values from 2-12 of phosphate buffered saline solution. The proposed pH sensor showed robust sensitivity of -43.74 ± 0.80 mV/pH and a quick response time of less than 10 s. Moreover, the repeatability, reproducibility and stability of the presented pH sensor were also studied.

De Novo Transcriptional Analysis of Alfalfa in Response to Saline-Alkaline Stress.

PubMed

An, Yi-Min; Song, Li-Li; Liu, Ying-Rui; Shu, Yong-Jun; Guo, Chang-Hong

2016-01-01

Saline-alkaline stress, caused by high levels of harmful carbonate salts and high soil pH, is a major abiotic stress that affects crop productivity. Alfalfa is a widely cultivated perennial forage legume with some tolerance to biotic and abiotic stresses, especially to saline-alkaline stress. To elucidate the mechanism underlying plant saline-alkaline tolerance, we conducted transcriptome analysis of whole alfalfa seedlings treated with saline-alkaline solutions for 0 day (control), 1 day (short-term treatment), and 7 days (long-term treatment) using ion torrent sequencing technology. A transcriptome database dataset of 53,853 unigenes was generated, and 2,286 and 2,233 genes were differentially expressed in the short-term and long-term treatment, respectively. Gene ontology analysis revealed 14 highly enriched pathways and demonstrated the differential response of metabolic pathways between the short-term and long-term treatment. The expression levels of 109 and 96 transcription factors were significantly altered significantly after 1 day and 7 days of treatment, respectively. Specific responses of peroxidase, flavonoids, and the light pathway component indicated that the antioxidant capacity was one of the central mechanisms of saline-alkaline stress tolerance response in alfalfa. Among the 18 differentially expressed genes examined by real time PCR, the expression levels of eight genes, including inositol transporter, DNA binding protein, raffinose synthase, ferritin, aldo/keto reductase, glutathione S-transferase, xyloglucan endotrans glucosylase, and a NAC transcription factor, exhibited different patterns in response to saline and alkaline stress. The expression levels of the NAC transcription factor and glutathione S-transferase were altered significantly under saline stress and saline-alkaline stress; they were upregulated under saline-alkaline stress and downregulated under salt stress. Physiology assays showed an increased concentration of reactive oxygen

De Novo Transcriptional Analysis of Alfalfa in Response to Saline-Alkaline Stress

PubMed Central

An, Yi-Min; Song, Li-Li; Liu, Ying-Rui; Shu, Yong-Jun; Guo, Chang-Hong

2016-01-01

Saline-alkaline stress, caused by high levels of harmful carbonate salts and high soil pH, is a major abiotic stress that affects crop productivity. Alfalfa is a widely cultivated perennial forage legume with some tolerance to biotic and abiotic stresses, especially to saline-alkaline stress. To elucidate the mechanism underlying plant saline-alkaline tolerance, we conducted transcriptome analysis of whole alfalfa seedlings treated with saline-alkaline solutions for 0 day (control), 1 day (short-term treatment), and 7 days (long-term treatment) using ion torrent sequencing technology. A transcriptome database dataset of 53,853 unigenes was generated, and 2,286 and 2,233 genes were differentially expressed in the short-term and long-term treatment, respectively. Gene ontology analysis revealed 14 highly enriched pathways and demonstrated the differential response of metabolic pathways between the short-term and long-term treatment. The expression levels of 109 and 96 transcription factors were significantly altered significantly after 1 day and 7 days of treatment, respectively. Specific responses of peroxidase, flavonoids, and the light pathway component indicated that the antioxidant capacity was one of the central mechanisms of saline-alkaline stress tolerance response in alfalfa. Among the 18 differentially expressed genes examined by real time PCR, the expression levels of eight genes, including inositol transporter, DNA binding protein, raffinose synthase, ferritin, aldo/keto reductase, glutathione S-transferase, xyloglucan endotrans glucosylase, and a NAC transcription factor, exhibited different patterns in response to saline and alkaline stress. The expression levels of the NAC transcription factor and glutathione S-transferase were altered significantly under saline stress and saline-alkaline stress; they were upregulated under saline-alkaline stress and downregulated under salt stress. Physiology assays showed an increased concentration of reactive oxygen

Fluid resuscitation with lactated Ringer’s solution vs normal saline in acute pancreatitis: A triple-blind, randomized, controlled trial

PubMed Central

Herrera-Marante, Iván; González-Camacho, Verónica; Bonjoch, Laia; Quesada-Vázquez, Noé; Almenta-Saavedra, Isabel; Miralles-Maciá, Cayetano; Acevedo-Piedra, Nelly G; Roger-Ibáñez, Manuela; Sánchez-Marin, Claudia; Osuna-Ligero, Rosa; Gracia, Ángel; Llorens, Pere; Zapater, Pedro; Singh, Vikesh K; Moreu-Martín, Rocío; Closa, Daniel

2017-01-01

Background Little is known regarding the optimal type of fluid resuscitation in acute pancreatitis (AP). Objective The objective of this article was to compare the effect of lactated Ringer’s solution (LR) vs normal saline (NS) in the inflammatory response in AP. Methods We conducted a triple-blind, randomized, controlled trial. Patients ≥ 18 admitted with AP were eligible. Patients were randomized to receive LR or NS. Primary outcome variables were number of systemic inflammatory response syndrome (SIRS) criteria at 24 hours, 48 hours and 72 hours and blood C-reactive protein (CRP) levels at 48 hours and 72 hours. In vitro complementary experiments were performed to further explore the interaction between pH, lactate and inflammation. Results Nineteen patients receiving LR and 21 receiving NS were analyzed. The median (p25–p75) number of SIRS criteria at 48 hours were 1 (1–2) for NS vs 1 (0–1) for LR, p = 0.060. CRP levels (mg/l) were as follows: at 48 hours NS 166 (78–281) vs LR 28 (3–124), p = 0.037; at 72 hours NS 217 (59–323) vs LR 25 (3–169), p = 0.043. In vitro, LR inhibited the induction of inflammatory phenotype of macrophages and NF-κB activation. This effect was not observed when using Ringer’s solution without lactate, suggesting a direct anti-inflammatory effect of lactate. Conclusions Lactated Ringer’s is associated with an anti-inflammatory effect in patients with acute pancreatitis. PMID:29435315

Synovitis induced by joint lavage with hypertonic saline solutions in healthy dairy calves

PubMed Central

Achard, Damien; Francoz, David; Desrochers, André; Girard, Christiane; Piché, Caroline

2012-01-01

The objective of this study was to evaluate the effect of a single joint lavage with 7.2% or 15% hypertonic saline solutions (HSS) on the tarsocrural joints of healthy calves. The tarsi of 10 calves were randomly lavaged with 7.2% HSS, 15% HSS, or isotonic saline. Synovial fluid samples were collected aseptically on days 1 (before joint lavage), 2, 3, 4, and 8 for complete cytological analysis. Lameness, joint swelling, and pain were recorded daily. Calves were euthanized on day 8 for gross and histological analyses of synovial membranes and articular cartilage. Synovitis was evaluated using a scoring system reflecting inflammatory changes in synovial membranes. Joints irrigated with HSS were more distended and painful compared with isotonic control joints. Swelling decreased consistently in the joints lavaged with 7.2% HSS, whereas it remained unchanged in joints lavaged with 15% HSS. Slight to moderate lameness was observed in the joints lavaged with 15% HSS. In comparison to isotonic saline joints, total protein concentration was significantly increased on day 2 and 3 for the joints lavaged with 7.2% HSS (P ≤ 0.01) and on days 2, 3, and 4 in the joints lavaged with 15% HSS (P ≤ 0.0006). Gross and histological findings revealed that synovitis was more severe in the joints lavaged with 15% HSS but variable in the joints lavaged with 7.2% HSS. No significant differences were observed for the articular cartilage. Fifteen percent HSS is not recommended for joint lavage. Although irrigation with 7.2% HSS may induce a variable synovitis, it was found appropriate for joint lavage. Its effects on septic joints remain undetermined. PMID:23024450

Hydrogeologic processes in saline systems: Playas, sabkhas, and saline lakes

USGS Publications Warehouse

Yechieli, Y.; Wood, W.W.

2002-01-01

Pans, playas, sabkhas, salinas, saline lakes, and salt flats are hydrologically similar, varying only in their boundary conditions. Thus, in evaluating geochemical processes in these systems, a generic water and solute mass-balance approach can be utilized. A conceptual model of a coastal sabkha near the Arabian Gulf is used as an example to illustrate the various water and solute fluxes. Analysis of this model suggests that upward flux of ground water from underlying formations could be a major source of solutes in the sabkha, but contribute only a small volume of the water. Local rainfall is the main source of water in the modeled sabkha system with a surprisingly large recharge-to-rainfall ratio of more than 50%. The contribution of seawater to the solute budget depends on the ratio of the width of the supratidal zone to the total width and is generally confined to a narrow zone near the shoreline of a typical coastal sabkha. Because of a short residence time of water, steady-state flow is expected within a short time (50,000 years). The solute composition of the brine in a closed saline system depends largely on the original composition of the input water. The high total ion content in the brine limits the efficiency of water-rock interaction and absorption. Because most natural systems are hydrologically open, the chemistry of the brines and the associated evaporite deposits may be significantly different than that predicted for hydrologically closed systems. Seasonal changes in temperature of the unsaturated zone cause precipitation of minerals in saline systems undergoing evaporation. Thus, during the hot dry season months, minerals exhibit retrograde solubility so that gypsum, anhydrite and calcite precipitate. Evaporation near the surface is also a major process that causes mineral precipitation in the upper portion of the unsaturated zone (e.g. halite and carnallite), provided that the relative humidity of the atmosphere is less than the activity of water

Anomalous pH-Dependent Nanofluidic Salinity Gradient Power.

PubMed

Yeh, Li-Hsien; Chen, Fu; Chiou, Yu-Ting; Su, Yen-Shao

2017-12-01

Previous studies on nanofluidic salinity gradient power (NSGP), where energy associated with the salinity gradient can be harvested with ion-selective nanopores, all suggest that nanofluidic devices having higher surface charge density should have higher performance, including osmotic power and conversion efficiency. In this manuscript, this viewpoint is challenged and anomalous counterintuitive pH-dependent NSGP behaviors are reported. For example, with equal pH deviation from its isoelectric point (IEP), the nanopore at pH < IEP is shown to have smaller surface charge density but remarkably higher NSGP performance than that at pH > IEP. Moreover, for sufficiently low pH, the NSGP performance decreases with lowering pH (increasing nanopore charge density). As a result, a maximum osmotic power density as high as 5.85 kW m -2 can be generated along with a conversion efficiency of 26.3% achieved for a single alumina nanopore at pH 3.5 under a 1000-fold concentration ratio. Using the rigorous model with considering the surface equilibrium reactions on the pore wall, it is proved that these counterintuitive surface-charge-dependent NSGP behaviors result from the pH-dependent ion concentration polarization effect, which yields the degradation in effective concentration ratio across the nanopore. These findings provide significant insight for the design of next-generation, high-performance NSGP devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Calcium Hypochlorite Solutions: Evaluation of Surface Tension and Effect of Different Storage Conditions and Time Periods over pH and Available Chlorine Content.

PubMed

Leonardo, Natália Gomes e Silva; Carlotto, Israel Bangel; Luisi, Simone Bonato; Kopper, Patrícia Maria Poli; Grecca, Fabiana Soares; Montagner, Francisco

2016-04-01

The aim of this study was to evaluate the pH and the available chlorine content from sodium hypochlorite (NaOCl) and calcium hypochlorite (Ca[OCl]2) solutions stored in different conditions and time periods and the surface tension of Ca(OCl)2 solutions in comparison with NaOCl. Solutions at 0.5%, 1%, 2.5%, and 5.25% concentrations were prepared. The pH level and the available chlorine content of freshly prepared solutions and solutions stored for 30, 60, and 90 days at 25°C, 4°C, or 37°C were evaluated in a digital pH meter and by titration, respectively. Surface tension was tested using a Du Nouy tensiometer (Sigma 702, Force Tensiometer; Attension, Espoo, Finland). Descriptive and inferential statistical analyses were performed. A precipitate formed by 2.5% and 5.25% Ca(OCl)2 solutions was observed. Ca(OCl)2 showed a higher concentration of available chlorine than NaOCl. Both 2.5% and 5.25% NaOCl and Ca(OCl)2 had a decrease in the available chlorine content when compared with freshly prepared solutions; 0.5% and 1% NaOCl tend to have a lower pH compared with 0.5% and 1% Ca(OCl)2. NaOCl, 5.25%, showed higher pH compared with 5.25% Ca(OCl)2. NaOCl and Ca(OCl)2 in 0.5% and 1% concentrations tend to show a reduced pH level, whereas 2.5% and 5.25% solutions showed an increase in pH. The heat contributed to the instability of the solutions. NaOCl showed lower surface tension values than Ca(OCl)2. Ca(OCl)2 solutions are extremely alkaline and tend to have more available chlorine content than NaOCl but have a higher surface tension than NaOCl. Regarding the available chlorine content, these solutions tend to be stable to 30 days of storage when kept at 4°C or at 25°C. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Influence of solution chemistry on the boron content in inorganic calcite grown in artificial seawater

NASA Astrophysics Data System (ADS)

Uchikawa, Joji; Harper, Dustin T.; Penman, Donald E.; Zachos, James C.; Zeebe, Richard E.

2017-12-01

The ratio of boron to calcium (B/Ca) in marine biogenic carbonates has been proposed as a proxy for properties of seawater carbonate chemistry. Applying this proxy to planktic foraminifera residing in the surface seawater largely in equilibrium with the atmosphere may provide a valuable handle on past atmospheric CO2 concentrations. However, precise controls on B/Ca in planktic foraminifera remain enigmatic because it has been shown to depend on multiple physicochemical seawater properties. To help establish a firm inorganic basis for interpreting the B/Ca records, we examined the effect of a suite of chemical parameters ([Ca2+], pH, [DIC], salinity and [PO43-]) on B/Ca in inorganic calcite precipitated in artificial seawater. These parameters were primarily varied individually while keeping all others constant, but we also tested the influence of pH and [DIC] at a constant calcite precipitation rate (R) by concurrent [Ca2+] adjustments. In the simple [Ca2+], pH and [DIC] experiments, both R and B/Ca increased with these parameters. In the pH-[Ca2+] and [DIC]-[Ca2+] experiments at constant R, on the other hand, B/Ca was invariant at different pH and decreased with [DIC], respectively. These patterns agree with the behavior of solution [BTotal/DIC] ratio such that, at a fixed [BTotal], it is independent of pH but decreases with [DIC]. Based on these results, R and [BTotal/DIC] ratio appear to be the primary controls on B/Ca in inorganic calcite, suggesting that both B(OH)4- and B(OH)3 are possibly involved in B incorporation. Moreover, B/Ca modestly increased with salinity and [PO43-]. Inorganic calcite precipitated at higher R and in the presence of oxyanions such as SO42- and PO43- in growth solutions often undergoes surface roughening due to formation of crystallographic defects, vacancies and, occasionally, amorphous/hydrous CaCO3. These non-lattice sites may provide additional space for B, particularly B(OH)3. Consequently, besides the macroscopic influence of

Influence of albumin on the electrochemical behaviour of Zr in phosphate buffered saline solutions.

PubMed

Wang, Lu-Ning; Huang, Xian-Qiu; Shinbine, Alyssa; Luo, Jing-Li

2013-02-01

The corrosion behaviour of Zr in phosphate buffered saline (PBS) solutions with various concentrations (0-4 g L(-1)) of albumin was studied by electrochemical techniques and surface analysis. Addition of albumin to PBS solutions moved the open circuit potential (OCP) to less nobler direction. OCP, polarization resistance and impedance increased and the corrosion current decreased over immersion duration. At early stages of immersion, the resistance was increased with the concentration of albumin because of the high adsorption kinetics of albumin on metal. After the long term immersion, the resistance in PBS without albumin was higher than PBS with albumin owing to the anodic dissolution effect of albumin on metal. According to the analysis of effective capacitances, a normal distribution of time-constants was proposed to estimate the surface film on Zr. A corrosion mechanism of Zr in PBS with different albumin was proposed based on electrochemical analysis.

pH Sensing Properties of Flexible, Bias-Free Graphene Microelectrodes in Complex Fluids: From Phosphate Buffer Solution to Human Serum.

PubMed

Ping, Jinglei; Blum, Jacquelyn E; Vishnubhotla, Ramya; Vrudhula, Amey; Naylor, Carl H; Gao, Zhaoli; Saven, Jeffery G; Johnson, Alan T Charlie

2017-08-01

Advances in techniques for monitoring pH in complex fluids can have a significant impact on analytical and biomedical applications. This study develops flexible graphene microelectrodes (GEs) for rapid (<5 s), very-low-power (femtowatt) detection of the pH of complex biofluids by measuring real-time Faradaic charge transfer between the GE and a solution at zero electrical bias. For an idealized sample of phosphate buffer solution (PBS), the Faradaic current is varied monotonically and systematically with the pH, with a resolution of ≈0.2 pH unit. The current-pH dependence is well described by a hybrid analytical-computational model, where the electric double layer derives from an intrinsic, pH-independent (positive) charge associated with the graphene-water interface and ionizable (negative) charged groups. For ferritin solution, the relative Faradaic current, defined as the difference between the measured current response and a baseline response due to PBS, shows a strong signal associated with ferritin disassembly and the release of ferric ions at pH ≈2.0. For samples of human serum, the Faradaic current shows a reproducible rapid (<20 s) response to pH. By combining the Faradaic current and real-time current variation, the methodology is potentially suitable for use to detect tumor-induced changes in extracellular pH. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigations in Marine Chemistry: Salinity II.

ERIC Educational Resources Information Center

Schlenker, Richard M.

Presented is a science activity in which the student investigates methods of calibration of a simple conductivity meter via a hands-on inquiry technique. Conductivity is mathematically compared to salinity using a point slope formula and graphical techniques. Sample solutions of unknown salinity are provided so that the students can sharpen their…

Adsorption properties of the nanozirconia/anionic polyacrylamide system-Effects of surfactant presence, solution pH and polymer carboxyl groups content

NASA Astrophysics Data System (ADS)

Wiśniewska, Małgorzata; Chibowski, Stanisław; Urban, Teresa

2016-05-01

The adsorption mechanism of anionic polyacrylamide (PAM) on the nanozirconia surface was examined. The effects of solution pH, carboxyl groups content in macromolecules and anionic surfactant (sodium dodecyl sulfate-SDS) addition were determined. The more probable structure of polymer adsorption layer was characterized based on the data obtained from spectrophotometry, viscosimetry and potentiometric titration methods. The adsorbed amount of polymer, size of macromolecules in the solution and surface charge density of ZrO2 particles in the absence and presence of PAM were assessed, respectively. Analysis of these results indicated that the increase of solution pH and content of carboxyl groups in the polymeric chains lead to more expanded conformations of adsorbing macromolecules. As a result, the adsorption of anionic polyacrylamide decreased. The SDS presence caused the significant increase of PAM adsorbed amount at pH 3, whereas at pH 6 and 9 the surfactant addition resulted in reduction of polymer adsorption level.

Salinity index determination of porous materials using open-ended probes

NASA Astrophysics Data System (ADS)

Szypłowska, Agnieszka; Kafarski, Marcin; Wilczek, Andrzej; Lewandowski, Arkadiusz; Skierucha, Wojciech

2017-01-01

The relations among soil water content, bulk electrical conductivity and electrical conductivity of soil solution can be described by a number of theoretical and empirical models. The aim of the paper is to examine the performance of open-ended coaxial probes with and without a short antenna in determination of complex dielectric permittivity spectra, moisture and salinity of porous materials using the salinity index approach. Glass beads of 0.26 and 1.24 mm average diameters moistened to various water contents with distilled water and KCl solutions were used to model the soil material. Due to the larger sensitivity zone, only the probe with the antenna enabled determination of bulk electrical conductivity and salinity index of the samples. The relations between bulk electrical conductivity and dielectric permittivity of the samples were highly linear, which was consistent with the salinity index model. The slope of the relation between salinity index and electrical conductivity of moistening solutions closely matched the value for 100 % sand presented in literature.

New analytical methodology for analysing S(IV) species at low pH solutions by one stage titration method (bichromatometry) with a clear colour change. Could potentially replace the state-of-art-method iodometry at low pH analysis due higher accuracy

PubMed Central

Galfi, Istvan; Virtanen, Jorma; Gasik, Michael M.

2017-01-01

A new, faster and more reliable analytical methodology for S(IV) species analysis at low pH solutions by bichromatometry is proposed. For decades the state of the art methodology has been iodometry that is still well justified method for neutral solutions, thus at low pH media possess various side reactions increasing inaccuracy. In contrast, the new methodology has no side reactions at low pH media, requires only one titration step and provides a clear color change if S(IV) species are present in the solution. The method is validated using model solutions with known concentrations and applied to analyses of gaseous SO2 from purged solution in low pH media samples. The results indicate that bichromatometry can accurately analyze SO2 from liquid samples having pH even below 0 relevant to metallurgical industrial processes. PMID:29145479

Relationship Between pH and Electrochemical Corrosion Behavior of Thermal-Sprayed Ni-Al-Coated Q235 Steel in Simulated Soil Solutions

NASA Astrophysics Data System (ADS)

Wei, Wei; Wu, Xin-qiang; Ke, Wei; Xu, Song; Feng, Bing; Hu, Bo-tao

2017-09-01

Electrochemical corrosion behavior of a thermal-sprayed Ni-Al-coated Q235 steel was investigated in the simulated soil solutions at different pH values using measurements of potentiodynamic polarization curves and electrochemical impedance spectroscopy as well as surface analyses including x-ray diffraction analysis, scanning electron microscope equipped with an energy-dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. The results showed that the corrosion resistance of the Ni-Al-coated Q235 steel was dependent on the pH of the test solution. From pH = 3.53 to pH = 4.79, the corrosion resistance of the coated steel increased rapidly. In the pH range from 4.79 to 12.26, the corrosion resistance exhibited no significant change. At pH 13.25, the corrosion resistance of the sample was found to decrease. The calculated corrosion rate of Ni-Al-coated Q235 steel was lower than that of the uncoated Q235 steel and galvanized steel in all the test solutions. Over a wide range of pH values, the Ni-Al-coated Q235 steel exhibited extremely good corrosion resistance. The experimental data together with the potential-pH diagrams provided a basis for a detailed discussion of the related corrosion mechanisms of the coated steel.

Modeling coliform-bacteria concentrations and pH in the salt-wedge reach of the Duwamish River Estuary, King County, Washington

USGS Publications Warehouse

Haushild, W.L.; Prych, Edmund A.

1976-01-01

Total- and fecal-coliform bacteria, plus pH, alkalinity, and dissolved inorganic carbon are water-quality parameters that have been added to an existing numerical model of water quality in the salt-wedge reach of the Duwamish River estuary in Washington. The coliform bacteria are modeled using a first-order decay (death) rate, which is a function of the local salinity, temperature, and daily solar radiation. The pH is computed by solving a set of chemical-equilibrium equations for carbonate-bicarbonate buffered aqueous solutions. Concentrations of total- and fecal-coliform bacteria computed by the model for the Duwamish River estuary during June-September 1971 generally agreed with observed concentrations within about 40 and 60 percent, respectively. The computed pH generally agreed with observed pH within about a 0.2 pH unit; however, for one 3-week period the computed pH was about a 0.4 unit lower than the observed pH. (Woodard-USGS)

Equilibrium partitioning of organic compounds to OASIS HLB® as a function of compound concentration, pH, temperature and salinity.

PubMed

Jeong, Yoonah; Schäffer, Andreas; Smith, Kilian

2017-05-01

Oasis hydrophilic lipophilic balance ® (Oasis HLB) is commonly employed in solid phase extraction (SPE) of environmental contaminants and within polar organic chemical integrative passive samplers (POCIS). In this study batch experiments were carried out to evaluate the relative affinity of a range of relevant organic pollutants to Oasis HLB in aqueous systems. The influence of sorbate concentration, temperature, pH, and salinity on the equilibrium sorption was investigated. Equilibrium partition ratios (K D ) of 28 compounds were determined, ranging over three orders of magnitude from 1.16 × 10 3  L/kg (atenolol) to 1.07 × 10 6  L/kg (isoproturon). The Freundlich model was able to describe the equilibrium partitioning to Oasis HLB, and an analysis of the thermodynamic parameters revealed the spontaneous and exothermic nature of the partitioning process. Ionic strength had only a minor effect on the partitioning, whereas pH had a considerable effect but only for ionizable compounds. The results show that apolar interactions between the Oasis HLB and analyte mainly determine the equilibrium partitioning. These research findings can be used to optimize the application of SPE and POCIS for analyses of environmental contaminants even in complex mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Polymer tensiometers in a saline environment.

NASA Astrophysics Data System (ADS)

van der Ploeg, Martine; Gooren, H. P. A.; Bakker, G.; Russell, W.; Hoogendam, C. W.; Huiskes, C.; Shouse, P.; de Rooij, G. H.

2010-05-01

It is estimated that 20% of all cultivated land and nearly half of the irrigated land is salt-affected, which pose major economic and environmental problems. Salinity may be the result of two processes; dryland and irrigation salinity. Dryland salinity is caused by a rise in the groundwater table, which occurs as a result of the replacement of deep-rooted, perennial native vegetation by shallow-rooted annual species meant for production. Irrigation salinity may occur as a result of poor water quality, poor drainage, or inefficient use of water. Consequently, new strategies to enhance crop yield stability on saline soils represent a major research priority (Botella et al. 2005). At the same time, native vegetation is capable of thriving under saline and/or dry conditions. The plant physiology of such vegetation has been investigated thoroughly, but the relation with in situ soil properties (soil moisture and salinity) may be more difficult to unravel as soil moisture sensors are less sensitive in dry soil, and the signal of most soil moisture content sensors is strongly attenuated by soil salinity. Recently, polymer tensiometer were developed that are able to measure matric potentials (closely related to a soil's moisture status) in dry soils. Polymer tensiometers consist of a solid ceramic, a stainless steel cup and a pressure transducer. The ceramic consist of a support layer and a membrane with 2 nm pore-size to prevent polymer leakage. Between the ceramic membrane and the pressure transducer a tiny chamber is located, which contains the polymer solution. The polymer's osmotic potential strongly reduces the total water potential inside the polymer tensiometer, which causes build-up of osmotic pressure. Polymer tensiometers would thus be an ideal instrument to measure in dry soil, if the polymer inside the tensiometer is not affected by the salts in the soil solution. We will address some key issues regarding the use of POTs in saline environments by showing

Interactions between globular proteins and F-actin in isotonic saline solution.

PubMed

Lakatos, S; Minton, A P

1991-10-05

Solutions of each of three different globular proteins (cytochrome c, chromophorically labeled serum albumin, and chromophorically labeled aldolase), mixed with another unlabeled globular protein or with fibrous actin, were prepared in pH 8.0 Tris-HCl buffer containing 0.15 M NaCl. Each solution was centrifuged at low speed, at 5 degrees C, until unassociated globular protein in solution achieved sedimentation equilibrium. Individual absorbance gradients of both macrosolutes in the mixtures subsequent to centrifugation were obtained via optical scans of the centrifuge tubes at two wavelengths. The gradients of each macrosolute in mixtures of two globular proteins revealed no association of globular proteins under the conditions of these experiments, but perturbation of the gradients of serum albumin, aldolase, and cytochrome c in the presence of F-actin indicated association of all three globular proteins with F-actin. Perturbation of actin gradients in the presence of serum albumin and aldolase suggested partial depolymerization of the F-actin by the globular protein. Analysis of the data with a simple phenomenological model relating free globular protein, bound globular protein, and total actin concentration provided estimates of the respective equilibrium constants for association of serum albumin and aldolase with F-actin, under the conditions of these experiments, of the order of 0.1 microM-1.

Influence of phosphate and solution pH on the mobility of ZnO nanoparticles in saturated sand.

PubMed

Li, Lingxiangyu; Schuster, Michael

2014-02-15

The mobility of nanoparticles (NPs) strongly depends on the chemical characterization of the environmental medium. However, the influence of phosphate on NPs mobility was ignored by scientists despite the serious phosphate contamination in natural environments. Hence, the influence of phosphate and solution pH on the mobility of zinc oxide nanoparticles (ZnO-NPs) was investigated in water-saturated sand representative of groundwater aquifers, which encompassed a range of P/Zn molar ratios (P/Zn: 0-4) and pH (4.8-10.0). The transport of ZnO-NPs was dramatically enhanced in the presence of phosphate, even at a low P/Zn molar ratio namely 0.25, and the retention of ZnO-NPs in the saturated sand decreased with increasing P/Zn molar ratio. Moreover, attachment efficiencies (α) and deposition rates (kd) of ZnO-NPs rapidly decreased with increasing P/Zn molar ratio. In contrast, the solution pH had negligible effects on ZnO-NP transport behavior under phosphate-abundant condition (P/Zn: 4). The distinct effects may be explained by the energy interaction between ZnO-NPs and sand surface under different conditions. Interestingly, under phosphate-abundant condition (P/Zn: 4), solution pH could strongly affect the transport of Zn(2+) in the water-saturated sand. Overall, this study outlines the importance of taking account of phosphate into risk assessment of NPs in the environment. Copyright © 2013 Elsevier B.V. All rights reserved.

The Determination of the pH of Standard Buffer Solution: A Laboratory Experiment.

ERIC Educational Resources Information Center

Harris, K. R.

1985-01-01

Describes an experiment which shows: (1) how measurements of the reaction electromotive force for the cell (Pt/glass/NaCl(aq,m),buffer/AgCl/Ag/Pt) can be utilized in determining the absolute pH of the buffer; and (2) the demonstration of the use of the Debye-Huckel model of an electrolyte solution in solving an important electrochemical problem.…

[Aluminum dissolution and changes of pH in soil solution during sorption of copper by aggregates of paddy soil].

PubMed

Xu, Hai-Bo; Zhao, Dao-Yuan; Qin, Chao; Li, Yu-Jiao; Dong, Chang-Xun

2014-01-01

Size fractions of soil aggregates in Lake Tai region were collected by the low-energy ultrasonic dispersion and the freeze-desiccation methods. The dissolution of aluminum and changes of pH in soil solution during sorption of Cu2+ and changes of the dissolution of aluminum at different pH in the solution of Cu2+ by aggregates were studied by the equilibrium sorption method. The results showed that in the process of Cu2+ sorption by aggregates, the aluminum was dissoluted and the pH decreased. The elution amount of aluminum and the decrease of pH changed with the sorption of Cu2+, both increasing with the increase of Cu2+ sorption. Under the same conditions, the dissolution of aluminum and the decrease of pH were in the order of coarse silt fraction > silt fraction > sand fraction > clay fraction, which was negatively correlated with the amount of iron oxide, aluminum and organic matter. It suggested that iron oxide, aluminum and organic matters had inhibitory and buffering effect on the aluminum dissolution and the decrease of pH during the sorption of Cu2+.

Removal of Soluble Strontium via Incorporation into Biogenic Carbonate Minerals by Halophilic Bacterium Bacillus sp. Strain TK2d in a Highly Saline Solution

PubMed Central

Dotsuta, Yuma; Nakano, Yuriko; Ochiai, Asumi; Utsunomiya, Satoshi; Ohnuki, Toshihiko

2017-01-01

ABSTRACT Radioactive strontium (90Sr) leaked into saline environments, including the ocean, from the Fukushima Daiichi Nuclear Power Plant after a nuclear accident. Since the removal of 90Sr using general adsorbents (e.g., zeolite) is not efficient at high salinity, a suitable alternative immobilization method is necessary. Therefore, we incorporated soluble Sr into biogenic carbonate minerals generated by urease-producing microorganisms from a saline solution. An isolate, Bacillus sp. strain TK2d, from marine sediment removed >99% of Sr after contact for 4 days in a saline solution (1.0 × 10−3 mol liter−1 of Sr, 10% marine broth, and 3% [wt/vol] NaCl). Transmission electron microscopy and energy-dispersive X-ray spectroscopy showed that Sr and Ca accumulated as phosphate minerals inside the cells and adsorbed at the cell surface at 2 days of cultivation, and then carbonate minerals containing Sr and Ca developed outside the cells after 2 days. Energy-dispersive spectroscopy revealed that Sr, but not Mg, was present in the carbonate minerals even after 8 days. X-ray absorption fine-structure analyses showed that a portion of the soluble Sr changed its chemical state to strontianite (SrCO3) in biogenic carbonate minerals. These results indicated that soluble Sr was selectively solidified into biogenic carbonate minerals by the TK2d strain in highly saline environments. IMPORTANCE Radioactive nuclides (134Cs, 137Cs, and 90Sr) leaked into saline environments, including the ocean, from the Fukushima Daiichi Nuclear Power Plant accident. Since the removal of 90Sr using general adsorbents, such as zeolite, is not efficient at high salinity, a suitable alternative immobilization method is necessary. Utilizing the known concept that radioactive 90Sr is incorporated into bones by biomineralization, we got the idea of removing 90Sr via incorporation into biominerals. In this study, we revealed the ability of the isolated ureolytic bacterium to remove Sr under high-salinity

Osmotic agents and buffers in peritoneal dialysis solution: monocyte cytokine release and in vitro cytotoxicity.

PubMed

Plum, J; Schoenicke, G; Grabensee, B

1997-09-01

Peritonitis remains a major problem in peritoneal dialysis. The incidence of peritonitis may be reduced by the use of more "biocompatible" peritoneal dialysis solutions that do not impair local host defense mechanisms, such as occurs with conventional lactate-buffered glucose solutions. In the present study, we investigated the use of bicarbonate and lactate as buffer systems and glucose, amino acids, and glucose polymer as osmotic agents on specific cellular functions of isolated fresh blood monocytes in vitro. The bicarbonate-buffered solutions had a physiologic pH (7.0 to 7.6). Lactate-buffered solutions were tested with a pH between 5.5 and 7.3. RPMI 1640 (Roswell Park Memorial Institute, supplied by Biochrom, Berlin, Germany) and phosphate-buffered saline were used as control mediums. The test solutions were incubated with 200,000 monocytes/mL for 45 minutes followed by a 1:1 mix with RPMI 1640 (with supplements) during a 24- or 4-hour tetrazolium bromide test (MTT test) recovery period. Constitutive and lipopolysaccharide (LPS)-stimulated release of interleukin-1beta (IL-1beta) and IL-6 in the supernatants as parameters of cellular host defense and lactate dehydrogenase concentrations and MTT-formazan production as parameters for cell cytotoxicity were measured. Significantly higher IL-6 and IL-1beta release was found in the bicarbonate-buffered solutions, both under basal conditions and after LPS stimulation, compared with the lactate-buffered solutions (LPS stimulation: 1% amino acids/34 mmol/L bicarbonate, IL-1beta: 1,166 +/- 192 pg/mL; 1.5% glucose/34 mmol/L bicarbonate, IL-1beta: 752 +/- 107 pg/mL; 1.5% glucose/35 mmol/L lactate/pH 5.5, IL-1beta: 174 +/- 51 pg/mL). Some of these differences could even be detected in spent dialysate after a 6-hour dwell in continuous ambulatory peritoneal dialysis patients (n = 10). A lower degree of cellular cytotoxicity (lactate dehydrogenase activity) and better-preserved metabolic activity (MTT test) also were found

Effect of pH on in vitro biocompatibility of orthodontic miniscrew implants.

PubMed

Galeotti, Angela; Uomo, Roberto; Spagnuolo, Gianrico; Paduano, Sergio; Cimino, Roberta; Valletta, Rosa; D'Antò, Vincenzo

2013-07-01

Although the clinical use of miniscrews has been investigated on a large scale, little is known about their biocompatibility. Since low pH can affect corrosion resistance, the aim of this study was to evaluate the cytotoxic effect of orthodontic miniscrews in different pH conditions. Four orthodontic miniscrews of stainless steel and grade IV and grade V titanium were immersed in a pH 7 and pH 4 saline solution for 1, 7, 14, 21, 28, and 84 days. Human osteogenic sarcoma cells (U2OS), permanent human keratinocytes (HaCat), and primary human gingival fibroblasts (HGF) were exposed to eluates, and the mitochondrial dehydrogenase activity was measured after 24 h to assess the cytoxicity. The results were analyzed using the Mann-Whitney U test (P<0.05). When exposed to pH 7-conditioned eluates, the cell lines showed an even greater viability than untreated cells. On the contrary, the results revealed a statistically significant decrease in U2OS, HaCat, and HGF viability after exposure to eluates obtained at pH 4. Among the cell lines tested, HGF showed the most significant decrease of mitochondrial activity. Interestingly, grade V titanium miniscrews caused highest toxic effects when immersed at pH 4. The results suggested that at pH 7, all the miniscrews are biocompatible while the eluates obtained at pH 4 showed significant cytotoxicity response. Moreover, different cell lines can produce different responses to miniscrew eluates.

Zr/ZrO2 sensors for in situ measurement of pH in high-temperature and -pressure aqueous solutions.

PubMed

Zhang, R H; Zhang, X T; Hu, S M

2008-04-15

The aim of this study is to develop new pH sensors that can be used to test and monitor hydrogen ion activity in hydrothermal conditions. A Zr/ZrO2 oxidation electrode is fabricated for in situ pH measurement of high-temperature aqueous solutions. This sensor responds rapidly and precisely to pH over a wide range of temperature and pressure. The Zr/ZrO2 electrode was made by oxidizing zirconium metal wire with Na2CO3 melt, which produced a thin film of ZrO2 on its surface. Thus, an oxidation-reduction electrode was produced. The Zr/ZrO2 electrode has a good electrochemical stability over a wide range of pH in high-temperature aqueous solutions when used with a Ag/AgCl reference electrode. Measurements of the Zr/ZrO2 sensor potential against a Ag/AgCl reference electrode is shown to vary linearly with pH between temperatures 20 and 200 degrees C. The slope of the potential versus pH at high temperature is slightly below the theoretical value indicated by the Nernst equation; such deviation is attributed to the fact that the sensor is not strictly at equilibrium with the solution to be tested in a short period of time. The Zr/ZrO2 sensor can be calibrated over the conditions that exist in the natural deep-seawater. Our studies showed that the Zr/ZrO2 electrode is a suitable pH sensor for the hydrothermal systems at midocean ridge or other geothermal systems with the high-temperature environment. Yttria-stabilized zirconia sensors have also been used to investigate the pH of hydrothermal fluids in hot springs vents at midocean ridge. These sensors, however, are not sensitive below 200 degrees C. Zr/ZrO2 sensors have wider temperature range and can be severed as good alternative sensors for measuring the pH of hydrothermal fluids.

Salting-out assisted liquid-liquid extraction with the aid of experimental design for determination of benzimidazole fungicides in high salinity samples by high-performance liquid chromatography.

PubMed

Wen, Yingying; Li, Jinhua; Yang, Fangfang; Zhang, Weiwei; Li, Weiran; Liao, Chunyang; Chen, Lingxin

2013-03-15

A novel method for the simultaneous separation and determination of four benzimidazole fungicides (i.e., carbendazim, fuberidazole, thiophanate-methyl and thiophanate) in high salinity samples was developed by using salting-out assisted liquid-liquid extraction (SALLE) via water-miscible acetonitrile as the extractant coupled with high-performance liquid chromatography. Box-Behnken design and response surface were employed to assist the optimization of SALLE conditions, including volume of salting-out solvent, the pH of sample solution and salting-out solvent as variable factors. The optimal salting-out parameters were obtained as follows: 2 mL of acetonitrile was added to 2 mL of sample solution with pH=4 and then 2 mL salting-out solvent containing 5 mol L(-1) sodium chloride at a pH of 7 was added to the solution for extraction. This procedure afforded a convenient and cost-saving operation with good cleanup ability for the benzimidazole fungicides, such as good linear relationships (R>0.996) between peak area and concentration from 2.5 ng mL(-1) to 500 ng mL(-1), low limits of detection between 0.14 ng mL(-1) and 0.38 ng mL(-1) and the intra-day precisions of retention time below 1.0%. The method recoveries obtained at fortified three concentrations for three seawater samples ranged from 60.4% to 99.1%. The simple, rapid and eco-benign SALLE based method proved potentially applicable for trace benzimidazole fungicides analysis in high salinity samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Use of the fluorescence of rhodamine B for the pH sensing of a glycine solution

NASA Astrophysics Data System (ADS)

Zhang, Weiwei; Shi, Kaixing; Shi, Jiulin; He, Xingdao

2016-10-01

The fluorescence of rhodamine B can be strongly affected by its environmental pH value. By directly introducing the dye into various glycine solution, the fluorescence was used to monitor the pH value in the range of 5.9 6.7. Two newly developed techniques for broadband analysis, the barycenter technique and the self-referenced intensity ratio technique, were employed to retrieve the pH sensing functions. While compared with traditional techniques, e.g. the peak shift monitoring, both the two new techniques presented finer precision. The obtained sensing functions may find their applications in the test of biochemical samples, body tissue fluid, water quality, etc.

Detecting crop yield reduction due to irrigation-induced soil salinization in South-West Russia

NASA Astrophysics Data System (ADS)

Argaman, E.; Beets, W.; Croes, J.; Keesstra, S.; Verzandvoort, S.; Zeiliguer, A.

2012-04-01

The South-European part of the Russian Federation has experienced serious land degradation in the form of soil salinization since the 1960s. This land degradation was caused by intensive, large-scale irrigation on reclaimed land in combination with the salt-rich nature of the substrate. Alkaline soil salinity is believed to be an important factor decreasing crop yield in this area. A large research effort has been directed to the effects of soil salinity on crops, there is a need for simple, easily determinable indicators of crop health and soil salinity in irrigated systems, that can help to detect crop water stress in an early stage. The objectives of this research were to study the effects of soil salinity and vegetation water stress on the performance of alfalfa crop yield and physiological crop properties, and to study the possibility to measure soil salinity and alkalinity and the crop water stress index at plot level using a thermal gun and a regular digital camera. The study area was located in Saratov District, in the South-West part of Russia. Variables on the surface energy balance, crop properties, soil properties and visible reflectance were measured on plots with alfalfa cultures in two fields with and without signs of alkaline soil salinity, and with and without irrigation in July 2009. The research showed no clear adverse effects of soil salinity and soil alkalinity on crop yield and physiological crop properties. Soil salinity, as reflected by the electric conductivity, positively affected the root biomass of alfalfa in the range of 0.15 to 1.52 dS/m . This was a result of EC levels being below the documented threshold to negatively affect Alfalfa, as would be the case in truly saline soils. The soil pH also showed a positive correlation with root biomass within the range of pH 6.2 and 8.5 . From the literature these pH values are generally believed to be too high to exhibit a positive relationship with root biomass. No relationship was found

Biochar-manure compost in conjunction with pyroligneous solution alleviated salt stress and improved leaf bioactivity of maize in a saline soil from central China: a 2-year field experiment.

PubMed

Lashari, Muhammad Siddique; Ye, Yingxin; Ji, Haishi; Li, Lianqing; Kibue, Grace Wanjiru; Lu, Haifei; Zheng, Jufeng; Pan, Genxing

2015-04-01

Salinity is a major stress threatening crop production in dry lands. A 2-year field experiment was conducted to assess the potential of a biochar product to alleviate salt-stress to a maize crop in a saline soil. The soil was amended with a compost at 12 t ha(-1) of wheat straw biochar and poultry manure compost (BPC), and a diluted pyroligneous solution (PS) at 0.15 t ha(-1) (BPC-PS). Changes in soil salinity and plant performance, leaf bioactivity were examined in the first (BPC-PS1) and second (BPC-PS2) year following a single amendment. While soil salinity significantly decreased, there were large increases in leaf area index, plant performance, and maize grain yield, with a considerable decrease in leaf electrolyte leakage when grown in amendments. Maize leaf sap nitrogen, phosphorus and potassium increased while sodium and chloride decreased, leaf bioactivity related to osmotic stress was significantly improved following the treatments. These effects were generally greater in the second than in the first year. A combined amendment of crop straw biochar with manure compost plus pyroligneous solution could help combat salinity stress to maize and improve productivity in saline croplands in arid/semi-arid regions threatened increasingly by global climate change. © 2014 Society of Chemical Industry.

Peroxidase-mediated polymerization of 1-naphthol: impact of solution pH and ionic strength.

PubMed

Bhandari, Alok; Xu, Fangxiang; Koch, David E; Hunter, Robert P

2009-01-01

Peroxidase-mediated oxidation has been proposed as a treatment method for naphthol-contaminated water. However, the impact of solution chemistry on naphthol polymerization and removal has not been documented. This research investigated the impact of pH and ionic strength on peroxidase-mediated removal of 1-naphthol in completely mixed batch reactors. The impact of hydrogen peroxide to 1-naphthol ratio and activity of horseradish peroxidase was also studied. Size exclusion chromatography was used to estimate the molecular weight distribution of oligomeric products, and liquid chromatography/mass spectrometry was used to estimate product structure. Naphthol transformation decreased with ionic strength, and substrate removal was lowest at neutral pHs. Solution pH influenced the size and the composition of the oligomeric products. An equimolar ratio of H(2)O(2):naphthol was sufficient for optimal naphthol removal. Polymerization products included naphthoquinones and oligomers derived from two, three, and four naphthol molecules. Our results illustrate the importance of water chemistry when considering a peroxidase-based approach for treatment of naphthol-contaminated waters.

pH sensing characteristics and biosensing application of solution-gated reduced graphene oxide field-effect transistors.

PubMed

Sohn, Il-Yung; Kim, Duck-Jin; Jung, Jin-Heak; Yoon, Ok Ja; Thanh, Tien Nguyen; Quang, Trung Tran; Lee, Nae-Eung

2013-07-15

Solution-gated reduced graphene oxide field-effect transistors (R-GO FETs) were investigated for pH sensing and biochemical sensing applications. A channel of a networked R-GO film formed by self-assembly was incorporated as a sensing layer into a solution-gated FET structure for pH sensing and the detection of acetylcholine (Ach), which is a neurotransmitter in the nerve system, through enzymatic reactions. The fabricated R-GO FET was sensitive to protons (H(+)) with a pH sensitivity of 29 mV/pH in terms of the shift of the charge neutrality point (CNP), which is attributed to changes in the surface potential caused by the interaction of protons with OH surface functional groups present on the R-GO surface. The R-GO FET immobilized with acetylcholinesterase (AchE) was used to detect Ach in the concentration range of 0.1-10mM by sensing protons generated during the enzymatic reactions. The results indicate that R-GO FETs provide the capability to detect protons, demonstrating their applicability as a biosensing device for enzymatic reactions. Copyright © 2013 Elsevier B.V. All rights reserved.

Salinity Gradients for Sustainable Energy: Primer, Progress, and Prospects.

PubMed

Yip, Ngai Yin; Brogioli, Doriano; Hamelers, Hubertus V M; Nijmeijer, Kitty

2016-11-15

Combining two solutions of different composition releases the Gibbs free energy of mixing. By using engineered processes to control the mixing, chemical energy stored in salinity gradients can be harnessed for useful work. In this critical review, we present an overview of the current progress in salinity gradient power generation, discuss the prospects and challenges of the foremost technologies - pressure retarded osmosis (PRO), reverse electrodialysis (RED), and capacitive mixing (CapMix) and provide perspectives on the outlook of salinity gradient power generation. Momentous strides have been made in technical development of salinity gradient technologies and field demonstrations with natural and anthropogenic salinity gradients (for example, seawater-river water and desalination brine-wastewater, respectively), but fouling persists to be a pivotal operational challenge that can significantly ebb away cost-competitiveness. Natural hypersaline sources (e.g., hypersaline lakes and salt domes) can achieve greater concentration difference and, thus, offer opportunities to overcome some of the limitations inherent to seawater-river water. Technological advances needed to fully exploit the larger salinity gradients are identified. While seawater desalination brine is a seemingly attractive high salinity anthropogenic stream that is otherwise wasted, actual feasibility hinges on the appropriate pairing with a suitable low salinity stream. Engineered solutions are foulant-free and can be thermally regenerative for application in low-temperature heat utilization. Alternatively, PRO, RED, and CapMix can be coupled with their analog separation process (reverse osmosis, electrodialysis, and capacitive deionization, respectively) in salinity gradient flow batteries for energy storage in chemical potential of the engineered solutions. Rigorous techno-economic assessments can more clearly identify the prospects of low-grade heat conversion and large-scale energy storage

Interactive effects of ocean acidification, elevated temperature, and reduced salinity on early-life stages of the pacific oyster.

PubMed

Ko, Ginger W K; Dineshram, R; Campanati, Camilla; Chan, Vera B S; Havenhand, Jon; Thiyagarajan, Vengatesen

2014-09-02

Ocean acidification (OA) effects on larvae are partially attributed for the rapidly declining oyster production in the Pacific Northwest region of the United States. This OA effect is a serious concern in SE Asia, which produces >80% of the world's oysters. Because climate-related stressors rarely act alone, we need to consider OA effects on oysters in combination with warming and reduced salinity. Here, the interactive effects of these three climate-related stressors on the larval growth of the Pacific oyster, Crassostrea gigas, were examined. Larvae were cultured in combinations of temperature (24 and 30 °C), pH (8.1 and 7.4), and salinity (15 psu and 25 psu) for 58 days to the early juvenile stage. Decreased pH (pH 7.4), elevated temperature (30 °C), and reduced salinity (15 psu) significantly delayed pre- and post-settlement growth. Elevated temperature lowered the larval lipid index, a proxy for physiological quality, and negated the negative effects of decreased pH on attachment and metamorphosis only in a salinity of 25 psu. The negative effects of multiple stressors on larval metamorphosis were not due to reduced size or depleted lipid reserves at the time of metamorphosis. Our results supported the hypothesis that the C. gigas larvae are vulnerable to the interactions of OA with reduced salinity and warming in Yellow Sea coastal waters now and in the future.

Measuring pH variability using an experimental sensor on an underwater glider

NASA Astrophysics Data System (ADS)

Hemming, Michael P.; Kaiser, Jan; Heywood, Karen J.; Bakker, Dorothee C. E.; Boutin, Jacqueline; Shitashima, Kiminori; Lee, Gareth; Legge, Oliver; Onken, Reiner

2017-05-01

Autonomous underwater gliders offer the capability of measuring oceanic parameters continuously at high resolution in both vertical and horizontal planes, with timescales that can extend to many months. An experimental ion-sensitive field-effect transistor (ISFET) sensor measuring pH on the total scale was attached to a glider during the REP14-MED experiment in June 2014 in the Sardinian Sea in the northwestern Mediterranean. During the deployment, pH was sampled at depths of up to 1000 m along an 80 km transect over a period of 12 days. Water samples were collected from a nearby ship and analysed for dissolved inorganic carbon concentration and total alkalinity to derive the pH for validating the ISFET sensor measurements. The vertical resolution of the pH sensor was good (1 to 2 m), but stability was poor and the sensor drifted in a non-monotonous fashion. In order to remove the sensor drift, a depth-constant time-varying offset was applied throughout the water column for each dive, reducing the spread of the data by approximately two-thirds. Furthermore, the ISFET sensor required temperature- and pressure-based corrections, which were achieved using linear regression. Correcting for this decreased the apparent sensor pH variability by a further 13 to 31 %. Sunlight caused an apparent sensor pH decrease of up to 0.1 in surface waters around local noon, highlighting the importance of shielding the sensor from light in future deployments. The corrected pH from the ISFET sensor is presented along with potential temperature, salinity, potential density anomalies (σθ), and dissolved oxygen concentrations (c(O2)) measured by the glider, providing insights into the physical and biogeochemical variability in the Sardinian Sea. The pH maxima were identified close to the depth of the summer chlorophyll maximum, where high c(O2) values were also found. Longitudinal pH variations at depth (σθ > 28. 8 kg m-3) highlighted the variability of water masses in the Sardinian

AND logic-like pH- and light-dual controlled drug delivery by surface modified mesoporous silica nanoparticles.

PubMed

Zhao, Junwei; He, Zhaoshuai; Li, Biao; Cheng, Tanyu; Liu, Guohua

2017-04-01

Recently, the controlled drug delivery system has become a potential platform for biomedical application. Herein, we developed a pH and light-dual controlled cargo release system exhibiting AND logic based on MCM-41 mesoporous silica nanoparticles, which was surface modified using β-cyclodextrin (β-CD) with imine bond and azobenzene derivative. The complex of β-CD and azobenzene derivative effectively blocked the cargo delivery in pH=7.0 phosphate buffered saline (PBS) solution without 365nm UV light irradiation. The cargo was fully released when both factors of acidic environment (pH=5.0 PBS) and 365nm UV light irradiation were satisfied, meanwhile only very little cargo was delivered if one factor was satisfied. The result also demonstrates that the opening/closing of the gate and the release of the cargo in small portions can be controlled. Copyright © 2016 Elsevier B.V. All rights reserved.

Salinization and Saline Environments

NASA Astrophysics Data System (ADS)

Vengosh, A.

2003-12-01

One of the most conspicuous phenomena of water-quality degradation, particularly in arid and semi-arid zones, is salinization of water and soil resources. Salinization is a long-term phenomenon, and during the last century many aquifers and river basins have become unsuitable for human consumption owing to high levels of salinity. Future exploitation of thousands of wells in the Middle East and in many other water-scarce regions in the world depends, to a large extent, on the degree and rate of salinization. Moreover, every year a large fraction of agricultural land is salinized and becomes unusable.Salinization is a global environmental phenomenon that affects many different aspects of our life (Williams, 2001a, b): changing the chemical composition of natural water resources (lakes, rivers, and groundwater), degrading the quality of water supply to the domestic and agriculture sectors, contribution to loss of biodiversity, taxonomic replacement by halotolerant species ( Williams, 2001a, b), loss of fertile soil, collapse of agricultural and fishery industries, changing of local climatic conditions, and creating severe health problems (e.g., the Aral Basin). The damage due to salinity in the Colorado River Basin alone, for example, ranges between 500 and 750 million per year and could exceed 1 billion per year if the salinity in the Imperial Dam increases from 700 mg L-1 to 900 mg L-1 (Bureau of Reclamation, 2003, USA). In Australia, accelerating soil salinization has become a massive environmental and economic disaster. Western Australia is "losing an area equal to one football oval an hour" due to spreading salinity ( Murphy, 1999). The annual cost for dryland salinity in Australia is estimated as AU700 million for lost land and AU$130 million for lost production ( Williams et al., 2002). In short, the salinization process has become pervasive.Salinity in water is usually defined by the chloride content (mg L-1) or total dissolved solids content (TDS, mg L-1or g

Incomplete turgor adjustment in Cladophora rupestrisunder fluctuating salinity regimes

NASA Astrophysics Data System (ADS)

Wiencke, Christian; Gorham, John; Tomos, Deri; Davenport, John

1992-04-01

Turgor pressure fluctuates strongly in Cladophora rupestrissubjected to low salinities and shows only a small tendency to readjust to the normal value in full seawater (incomplete turgor adjustment). This was revealed by direct turgor pressure measurements and by chemical analyses of osmotic solutes after exposure of upper and lower shore Cladophorato the different salinity regimes occurring in the intertidal zone or representing steady state osmotic acclimation. The main internal osmotic solutes were K +, Cl -, amino acids, NO 3-and glycine betaine. Na +, SO 42-and PO 43-were of less importance. The sum of the charges on the cations was similar to that for the anions. K +, Cl -and, to a lesser extent, amino acids were responsible for limited turgor pressure adjustment which did occur. The concentrations of the major osmotic solutes were influenced not only by salinity but also by light: those of amino acids and NO 3-were increased while those of K +and Cl -were decreased under illumination. Cladophorapopulations from the upper and lower shore differed in their ability to restore internal K +and Cl -levels on transfer to full seawater after long term exposure to low salinity. This may indicate ecotypic variation.

Tolerance of Hordeum marinum accessions to O2 deficiency, salinity and these stresses combined

PubMed Central

Malik, Al Imran; English, Jeremy Parker; Colmer, Timothy David

2009-01-01

Background and Aims When root-zone O2 deficiency occurs together with salinity, regulation of shoot ion concentrations is compromised even more than under salinity alone. Tolerance was evaluated amongst 34 accessions of Hordeum marinum, a wild species in the Triticeae, to combined salinity and root-zone O2 deficiency. Interest in H. marinum arises from the potential to use it as a donor for abiotic stress tolerance into wheat. Methods Two batches of 17 H. marinum accessions, from (1) the Nordic Gene Bank and (2) the wheat belt of Western Australia, were exposed to 0·2 or 200 mol m−3 NaCl in aerated or stagnant nutrient solution for 28–29 d. Wheat (Triticum aestivum) was included as a sensitive check species. Growth, root porosity, root radial O2 loss (ROL) and leaf ion (Na+, K+, Cl−) concentrations were determined. Key Results Owing to space constraints, this report is focused mainly on the accessions from the Nordic Gene Bank. The 17 accessions varied in tolerance; relative growth rate was reduced by 2–38 % in stagnant solution, by 8–42 % in saline solution (aerated) and by 39–71 % in stagnant plus saline treatment. When in stagnant solution, porosity of adventitious roots was 24–33 %; salinity decreased the root porosity in some accessions, but had no effect in others. Roots grown in stagnant solution formed a barrier to ROL, but variation existed amongst accessions in apparent barrier ‘strength’. Leaf Na+ concentration was 142–692 µmol g−1 d. wt for plants in saline solution (aerated), and only increased to 247–748 µmol g−1 d. wt in the stagnant plus saline treatment. Leaf Cl− also showed only small effects of stagnant plus saline treatment, compared with saline alone. In comparison with H. marinum, wheat was more adversely affected by each stress alone, and particularly when combined; growth reductions were greater, adventitious root porosity was 21 %, it lacked a barrier to ROL, leaf K+ declined to lower levels, and leaf Na+ and

First-Principles pH Theory

NASA Astrophysics Data System (ADS)

Kim, Yong-Hyun; Zhang, S. B.

2006-03-01

Despite being one of the most important macroscopic measures and a long history even before the quantum mechanics, the concept of pH has rarely been mentioned in microscopic theories, nor being incorporated computationally into first-principles theory of aqueous solutions. Here, we formulate a theory for the pH dependence of solution formation energy by introducing the proton chemical potential as the microscopic counterpart of pH in atomistic solution models. Within the theory, the general acid-base chemistry can be cast in a simple pictorial representation. We adopt density-functional molecular dynamics to demonstrate the usefulness of the method by studying a number of solution systems including water, small solute molecules such as NH3 and HCOOH, and more complex amino acids with several functional groups. For pure water, we calculated the auto- ionization constant to be 13.2 with a 95 % accuracy. For other solutes, the calculated dissociation constants, i.e., the so- called pKa, are also in reasonable agreement with experiments. Our first-principles pH theory can be readily applied to broad solution chemistry problems such as redox reactions.

pH and Organic Carbon Dose Rates Control Microbially Driven Bioremediation Efficacy in Alkaline Bauxite Residue.

PubMed

Santini, Talitha C; Malcolm, Laura I; Tyson, Gene W; Warren, Lesley A

2016-10-18

Bioremediation of alkaline tailings, based on fermentative microbial metabolisms, is a novel strategy for achieving rapid pH neutralization and thus improving environmental outcomes associated with mining and refining activities. Laboratory-scale bioreactors containing bauxite residue (an alkaline, saline tailings material generated as a byproduct of alumina refining), to which a diverse microbial inoculum was added, were used in this study to identify key factors (pH, salinity, organic carbon supply) controlling the rates and extent of microbially driven pH neutralization (bioremediation) in alkaline tailings. Initial tailings pH and organic carbon dose rates both significantly affected bioremediation extent and efficiency with lower minimum pHs and higher extents of pH neutralization occurring under low initial pH or high organic carbon conditions. Rates of pH neutralization (up to 0.13 mM H + produced per day with pH decreasing from 9.5 to ≤6.5 in three days) were significantly higher in low initial pH treatments. Representatives of the Bacillaceae and Enterobacteriaceae, which contain many known facultative anaerobes and fermenters, were identified as key contributors to 2,3-butanediol and/or mixed acid fermentation as the major mechanism(s) of pH neutralization. Initial pH and salinity significantly influenced microbial community successional trajectories, and microbial community structure was significantly related to markers of fermentation activity. This study provides the first experimental demonstration of bioremediation in bauxite residue, identifying pH and organic carbon dose rates as key controls on bioremediation efficacy, and will enable future development of bioreactor technologies at full field scale.

Stability of solutions of antineoplastic agents during preparation and storage for in vitro assays. General considerations, the nitrosoureas and alkylating agents.

PubMed

Bosanquet, A G

1985-01-01

In vitro drug sensitivity of tumour biopsies is currently being determined using a variety of methods. For these chemosensitivity assays many drugs are required at short notice, and this in turn means that the drugs must generally be stored in solution. There are, however, a number of potential problems associated with dissolving and storing drugs for in vitro use, which include (a) drug adsorption; (b) effects of freezing; (c) drug stability under the normal conditions of dilution and setting up of an in vitro assay; and (d) insolubility of drugs in normal saline (NS) or phosphate-buffered saline (PBS). These problems are considered in general, and some recommendations for use of solutions of drugs in in vitro assays are suggested. The nitrosoureas and alkylating agents are also investigated in greater detail in this respect. The nitrosoureas are found to be very labile in PBS at pH 7, with 5% degradation (t0.95) occurring in 10-50 min at room temperature. These values are increased about 10-fold on refrigeration and about 5- to 10-fold on reduction of the pH of the medium to pH 4-5. At pH 7 and room temperature, t0.95 is observed in under 1 h with the alkylating agents nitrogen mustard, chlorambucil, melphalan, 2,5-diaziridinyl-3,6-bis(2-hydroxyethylamino)-1,4-benzoquinone (BZQ), dibromodulcitol, dibromomannitol, treosulphan, and procarbazine. Of the other alkylating agents, 4-hydroperoxycylophosphamide (sometimes used in vitro in place of cyclophosphamide), busulphan, dianhydrogalactitol, aziridinylbenzoquinone (AZQ), and dacarbazine have a t0.95 of between 2 and 24 h, while ifosfamide and pentamethylmelamine are both stable in aqueous solution for greater than 7 days. About half the drugs studied in detail have been stored frozen in solution for in vitro use, although very little is known about their stability under these conditions.

The formation of stable pH gradients with weak monovalent buffers for isoelectric focusing in free solution

NASA Technical Reports Server (NTRS)

Mosher, Richard A.; Thormann, Wolfgang; Graham, Aly; Bier, Milan

1985-01-01

Two methods which utilize simple buffers for the generation of stable pH gradients (useful for preparative isoelectric focusing) are compared and contrasted. The first employs preformed gradients comprised of two simple buffers in density-stabilized free solution. The second method utilizes neutral membranes to isolate electrolyte reservoirs of constant composition from the separation column. It is shown by computer simulation that steady-state gradients can be formed at any pH range with any number of components in such a system.

An evaluation of MES (2(N-Morpholino)ethanesulfonic acid) and Amberlite IRC-50 as pH buffers for nutrient solution studies

NASA Technical Reports Server (NTRS)

Bugbee, B. G.; Salisbury, F. B.

1985-01-01

All buffering agents used to stabilize pH in hydroponic research have disadvantages. Inorganic buffers are absorbed and may become phytotoxic. Solid carbonate salts temporarily mitigate decreasing pH but provide almost no protection against increasing pH, and they alter nutrient absorption. Exchange resins are more effective, but we find that they remove magnesium and manganese from solution. We have tested 2(N-Morpholino)ethanesulfonic acid (MES) as a buffering agent at concentrations of 1 and 10 mol m-3 (1 and 10 mM) with beans, corn, lettuce, tomatoes, and wheat. MES appears to be biologically inert and does not interact significantly with other solution ions. Relative growth rates among controls and MES treatments were nearly identical for each species during the trial period. The pH was stabilized by 1 mol m-3 MES. This buffer warrants further consideration in nutrient research.

Double-pass Mach-Zehnder fiber interferometer pH sensor.

PubMed

Tou, Zhi Qiang; Chan, Chi Chiu; Hong, Jesmond; Png, Shermaine; Eddie, Khay Ming Tan; Tan, Terence Aik Huang

2014-04-01

A biocompatible fiber-optic pH sensor based on a unique double-pass Mach-Zehnder interferometer is proposed. pH responsive poly(2-hydroxyethyl methacrylate-co-2-(dimethylamino)ethyl methacrylate) hydrogel coating on the fiber swells/deswells in response to local pH, leading to refractive index changes that manifest as shifting of interference dips in the optical spectrum. The pH sensor is tested in spiked phosphate buffer saline and demonstrates high sensitivity of 1.71  nm/pH, pH 0.004 limit of detection with good responsiveness, repeatability, and stability. The proposed sensor has been successfully applied in monitoring the media pH in cell culture experiments to investigate the relationship between pH and cancer cell growth.

Fate of cadmium at the soil-solution interface: a thermodynamic study as influenced by varying pH at South 24 Parganas, West Bengal, India.

PubMed

Karak, Tanmoy; Paul, Ranjit Kumar; Das, Sampa; Das, Dilip K; Dutta, Amrit Kumar; Boruah, Romesh K

2015-11-01

A study on the sorption kinetics of Cd from soil solution to soils was conducted to assess the persistence of Cd in soil solution as it is related to the leaching, bioavailability, and potential toxicity of Cd. The kinetics of Cd sorption on two non-contaminated alkaline soils from Canning (22° 18' 48.02″ N and 88° 39' 29.0″ E) and Lakshmikantapur (22° 06' 16.61″ N and 88° 19' 08.66″ E) of South 24 Parganas, West Bengal, India, were studied using conventional batch experiment. The variable soil suspension parameters were pH (4.00, 6.00, 8.18, and 9.00), temperatures (308, 318, and 328 K) and Cd concentrations (5-100 mg L(-1)). The average rate coefficient (kavg) and half-life (t1/2) values indicate that the persistence of Cd in soil solution is influenced by both temperature and soil suspension pH. The concentration of Cd in soil solution decreases with increase of temperature; therefore, Cd sorption on the soil-solution interface is an endothermic one. Higher pH decreases the t 1/2 of Cd in soil solution, indicating that higher pH (alkaline) is not a serious concern in Cd toxicity than lower pH (acidic). Based on the energy of activation (Ea) values, Cd sorption in acidic pH (14.76±0.29 to 64.45±4.50 kJ mol(-1)) is a surface control phenomenon and in alkaline pH (9.33±0.09 to 44.60±2.01 kJ mol(-1)) is a diffusion control phenomenon The enthalpy of activation (ΔH∓) values were found to be between 7.28 and 61.73 kJ mol(-1). Additionally, higher positive energy of activation (ΔG∓) values (46.82±2.01 to 94.47±2.36 kJ mol(-1)) suggested that there is an energy barrier for product formation.

Adsorption of Hydrophobin-Protein Mixtures at the Air-Water Interface: The Impact of pH and Electrolyte.

PubMed

Tucker, Ian M; Petkov, Jordan T; Penfold, Jeffrey; Thomas, Robert K; Cox, Andrew R; Hedges, Nick

2015-09-15

The adsorption of the proteins β-casein, β-lactoglobulin, and hydrophobin, and the protein mixtures of β-casein/hydrophobin and β-lactoglobulin/hydrophobin have been studied at the air-water interface by neutron reflectivity, NR. Changing the solution pH from 7 to 2.6 has relatively little impact on the adsorption of hydrophobin or β-lactoglobulin, but results in a substantial change in the structure of the adsorbed layer of β-casein. In β-lactoglobulin/hydrophobin mixtures, the adsorption is dominated by the hydrophobin adsorption, and is independent of the hydrophobin or β-lactoglobulin concentration and solution pH. At pH 2.6, the adsorption of the β-casein/hydrophobin mixtures is dominated by the hydrophobin adsorption over the range of β-casein concentrations studied. At pH 4 and 7, the adsorption of β-casein/hydrophobin mixtures is dominated by the hydrophobin adsorption at low β-casein concentrations. At higher β-casein concentrations, β-casein is adsorbed onto the surface monolayer of hydrophobin, and some interpenetration between the two proteins occurs. These results illustrate the importance of pH on the intermolecular interactions between the two proteins at the interface. This is further confirmed by the impact of PBS, phosphate buffered saline, buffer and CaCl2 on the coadsorption and surface structure. The results provide an important insight into the adsorption properties of protein mixtures and their application in foam and emulsion stabilization.

Diluted povidone-iodine versus saline for dressing metal-skin interfaces in external fixation.

PubMed

Chan, C K; Saw, A; Kwan, M K; Karina, R

2009-04-01

To compare infection rates associated with 2 dressing solutions for metal-skin interfaces. 60 patients who underwent distraction osteogenesis with external fixators were equally randomised into 2 dressing solution groups (diluted povidone-iodine vs. saline). Fixations were attained using either rigid stainless steel 5-mm diameter half pins or smooth stainless steel 1.8-mm diameter wires. Half-pin fixation had one metal-skin interface, whereas wire fixation had 2 interfaces. Patients were followed up every 2 weeks for 6 months. Of all 788 metal-skin interfaces, 143 (18%) were infected: 72 (19%) of 371 in the diluted povidone-iodine group and 71 (17%) of 417 in the saline group. Dressing solution and patient age did not significantly affect infection rates. Half-pin fixation was more likely to become infected than wire fixation (25% vs 15%). Saline is as effective as diluted povidone-iodine as a dressing solution for metal-skin interfaces of external fixators. Saline is recommended in view of its easy availability and lower costs.

Influence of intramuscular granisetron on experimentally induced muscle pain by acidic saline.

PubMed

Louca, S; Ernberg, M; Christidis, N

2013-06-01

The aim of this study was to investigate whether intramuscular administration of the 5-HT(3) receptor antagonist granisetron reduces experimental muscle pain induced by repeated intramuscular injections of acidic saline into the masseter muscles. Twenty-eight healthy and pain-free volunteers, fourteen women and fourteen men participated in this randomized, double-blind and placebo-controlled study. After a screening examination and registration of the baseline pressure-pain threshold (PPT), the first simultaneous bilateral injections of 0·5 mL acidic saline (9 mg mL(-1) , pH 3·3) into the masseter muscles were performed. Two days later, PPT and pain (VAS) were re-assessed. The masseter muscle was then pre-treated with 0·5 mL granisetron (Kytril(®) 1 mg mL(-1) pH 5·3) on one side and control substance (isotonic saline, 9 mg mL(-1) pH 6) on the contralateral side. Two minutes thereafter a bilateral simultaneous injection of 0·5 mL acidic saline followed. The evoked pain intensity, pain duration, pain area and PPT were assessed. The volunteers returned 1 week later to re-assess VAS and PPT. On the side pre-treated with granisetron, the induced pain had significantly lower intensity and shorter duration (P < 0·05) compared with the side pre-treated with control. A subgroup analysis showed that the effect of granisetron on pain duration was significant only in women (P < 0·001), while the effect on peak pain and pain area were significant in both sexes. The results showed no significant change in PPT. In conclusion, these results indicate that granisetron has a pain-reducing effect on experimentally induced muscle pain by repeated acidic saline injection. © 2013 John Wiley & Sons Ltd.

Corrosion, ion release and Mott-Schottky probe of chromium oxide coatings in saline solution with potential for orthopaedic implant applications

NASA Astrophysics Data System (ADS)

Ogwu, A. A.; Oje, A. M.; Kavanagh, J.

2016-04-01

We report our investigation on chromium oxide thin film coatings that show a negligible ion release during electrochemical corrosion testing in saline solution. The chemical constituents of the films prepared by reactive magnetron sputtering were identified to be predominantly Cr2O3 based on Raman spectroscopy anti-symmetric stretching vibration modes for CrIII-O and other peaks and an FTIR spectroscopy E u vibrational mode at 409 cm-1. X-ray photoelectron spectroscopy, multiplet fitting for 2P 3/2 and 2P 1/2 states also confirmed the predominantly Cr2O3 stoichiometry in the films. The prepared chromium oxide coatings showed superior pitting corrosion resistance compared to the native chromium oxide films on bare uncoated stainless steel when tested under open circuit potential, potentiodynamic polarisation and cyclic voltammetry in saline solution. The chromium ion released into solution during the corrosion testing of stainless steel substrates coated with chromium oxide coatings was found to be negligibly small based on atomic absorption spectroscopy measurements. Our Mott-Schottky analysis investigation showed that the negligibly small ion release from the chromium oxide coated steel substrates is most likely due to a much lower defect density on the surface of the deposited coatings compared to the native oxide layer on the uncoated steel substrates. This opens up the opportunity for using chromium oxide surface coatings in hip, knee and other orthopaedic implants where possible metal ion release in vivo still poses a great challenge.

Toxicity of the molybdate anion in soil is partially explained by effects of the accompanying cation or by soil pH.

PubMed

Buekers, Jurgen; Mertens, Jelle; Smolders, Erik

2010-06-01

Previous studies have shown that toxicity of cationic trace metals in soil is partially confounded by effects of the accompanying anions. A similar assessment is reported here for toxicity of an oxyanion, i.e., molybdate (MoO(4) (2-)), the soil toxicity of which is relatively unexplored. Solubility and toxicity were compared between the soluble sodium molybdate (Na(2)MoO(4)) and the sparingly soluble molybdenum trioxide (MoO(3)). Confounding effects of salinity were excluded by referencing the Na(2)MoO(4) effect to that of sodium chloride (NaCl). The pH decrease from the acid MoO(3) amendment was equally referenced to a hydrochloric (HCl) treatment or a lime-controlled MoO(3) treatment. The concentrations of molybdenum (Mo) in soil solution or calcium chloride (CaCl(2)) 0.01 M extracts were only marginally affected by either MoO(3) or Na(2)MoO(4) as an Mo source after 10 to 13 days of equilibration. Effects of Mo on soil nitrification were fully confounded by associated changes in salinity or pH. Effects of Mo on growth of wheat seedlings (Triticum aestivum L) were more pronounced than those on nitrification, and toxicity thresholds were unaffected by the form of added Mo. The Mo thresholds for wheat growth were not confounded by pH or salinity at incipient toxicity. It is concluded that oxyanion toxicity might be confounded in relatively insensitive tests for which reference treatments should be included. Copyright 2010 SETAC.

Osmotic pressures and second virial coefficients for aqueous saline solutions of lysozyme

DOE PAGES

Moon, Y. U.; Anderson, C. O.; Blanch, H. W.; ...

2000-03-27

Experimental data at 25 °C are reported for osmotic pressures of aqueous solutions containing lysozyme and any one of the following salts: ammonium sulfate, ammonium oxalate and ammonium phosphate at ionic strength 1 or 3M. Data were obtained using a Wescor Colloid Membrane Osmometer at lysozyme concentrations from about 4 to 20 grams per liter at pH 4, 7 or 8. Osmotic second virial coefficients for lysozyme were calculated from the osmotic-pressure data. All coefficients were negative, increasing in magnitude with ionic strength. Furthermore, tesults are insensitive to the nature of the anion, but rise slightly in magnitude as themore » size of the anion increases.« less

Geophysical, geochemical and hydrological analyses of water-resource vulnerability to salinization: case of the Uburu-Okposi salt lakes and environs, southeast Nigeria

NASA Astrophysics Data System (ADS)

Ukpai, S. N.; Okogbue, C. O.

2017-11-01

Until this study, the location and depth of the saline units in Uburu-Okposi salt lake areas and environs have been unknown. This study aimed at delineating the saline lithofacies and dispersal configurations to water bodies, using electrical geophysical methods such as constant separation traversing (CST) and vertical electrical sounding (VES). Results showed weathered zones that represent aquifers mostly at the fourth geoelectric layer: between upper layered aquitards and underlying aquitards at depths 30-140 m. Lateral distribution of resistivity variance was defined by the CST, whereas the VES tool, targeted at low-resistivity zones, detected isolated saline units with less than 10 ohm-m at depths generally >78 m. The saline lithofacies were suspected to link freshwater zones via shear zones, which steer saline water towards the salt lakes and influence the vulnerability of groundwater to salinization. The level of salinization was verified by water sampling and analysis, and results showed general alkaline water type with a mean pH of 7.66. Water pollution was indicated: mean total dissolved solids (TDS) 550 mg/l, electrical conductivity (EC) 510 μS/cm, salinity 1.1‰, Cl- 200 mg/l, N03 -35.5 mg/l, Na+ 19.6 mg/l and Ca2+ 79.3 mg/l. The salinity is controlled by NaCl salt, as deduced from correlation analysis using the software package Statistical Product for Service Solutions (SPSS). Generally, concentrations of dissolved ions in the water of the area are enhanced via mechanisms such as evaporation, dissociation of salts, precipitation run off and leaching of dissolved rock minerals.

Method for producing rapid pH changes

DOEpatents

Clark, John H.; Campillo, Anthony J.; Shapiro, Stanley L.; Winn, Kenneth R.

1981-01-01

A method of initiating a rapid pH change in a solution by irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

Method for producing rapid pH changes

DOEpatents

Clark, J.H.; Campillo, A.J.; Shapiro, S.L.; Winn, K.R.

A method of initiating a rapid pH change in a solution comprises irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

Changes in biomechanical properties of glenohumeral joint capsules with adhesive capsulitis by repeated capsule-preserving hydraulic distensions with saline solution and corticosteroid.

PubMed

Koh, Eun S; Chung, Sun G; Kim, Tae Uk; Kim, Hee Chan

2012-12-01

To investigate whether capsule-preserving hydraulic distension with saline solution and corticosteroid for adhesive capsulitis induces biomechanical alterations in glenohumeral joint capsules along with clinical improvements. A case series. University outpatient clinic of physical medicine and rehabilitation. Eighteen patients with unilateral adhesive capsulitis. INTERVENTION AND MAIN OUTCOME MEASUREMENTS: Three hydraulic distensions with saline solution and corticosteroid were performed with 1-month intervals. To avoid rupturing capsules, all distensions were monitored by using real-time pressure-volume curves. Stiffness, maximal volume capacity, and pressure at the maximal volume capacity of the capsule were measured at each intervention. Clinical parameters, such as pain and range of motion, were recorded before, 3 days after, and 1 month after each distension. Stiffness decreased (47.6 ± 27.1 mm Hg/mL to 31.7 ± 18.4 mm Hg/mL to 24.2 ± 14.0 mm Hg/mL, mean SD) and maximal volume capacity increased (18.8 ± 7.3 mL to 20.5 ± 7.5 mL to 24.2 ± 7.0 mL, mean SD) significantly (P = .001 for both) at each repeated hydraulic distension. Pressure at the maximal volume capacity tended to decrease, but the decrements were not statistically significant (P = .662). The clinical parameters were significantly improved throughout and 1 month after the 3 repeat procedures (P < .05 for all). Capsule-preserving hydraulic distension changed the biomechanical properties of the glenohumeral joint capsule, lessening the stiffness and enlarging the volume capacity. These alterations were accompanied by improved range of motion and relief of pain. Repeated capsule-preserving hydraulic distension with saline solution and corticosteroid would be useful to treat adhesive capsulitis and to evaluate the treatment results. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Reactive solute transport in an acidic stream: Experimental pH increase and simulation of controls on pH, aluminum, and iron

USGS Publications Warehouse

Broshears, R.E.; Runkel, R.L.; Kimball, B.A.; McKnight, Diane M.; Bencala, K.E.

1996-01-01

Solute transport simulations quantitatively constrained hydrologic and geochemical hypotheses about field observations of a pH modification in an acid mine drainage stream. Carbonate chemistry, the formation of solid phases, and buffering interactions with the stream bed were important factors in explaining the behavior of pH, aluminum, and iron. The precipitation of microcrystalline gibbsite accounted for the behavior of aluminum; precipitation of Fe(OH)3 explained the general pattern of iron solubility. The dynamic experiment revealed limitations on assumptions that reactions were controlled only by equilibrium chemistry. Temporal variation in relative rates of photoreduction and oxidation influenced iron behavior. Kinetic limitations on ferrous iron oxidation and hydrous oxide precipitation and the effects of these limitations on field filtration were evident. Kinetic restraints also characterized interaction between the water column and the stream bed, including sorption and desorption of protons from iron oxides at the sediment-water interface and post-injection dissolution of the precipitated aluminum solid phase.

Quantifying the degradation of TNT and RDX in a saline environment with and without UV-exposure.

PubMed

Sisco, Edward; Najarro, Marcela; Bridge, Candice; Aranda, Roman

2015-06-01

Terrorist attacks in a maritime setting, such as the bombing of the USS Cole in 2000, or the detection of underwater mines, require the development of proper protocols to collect and analyse explosive material from a marine environment. In addition to proper analysis of the explosive material, protocols must also consider the exposure of the material to potentially deleterious elements, such as UV light and salinity, time spent in the environment, and time between storage and analysis. To understand how traditional explosives would be affected by such conditions, saline solutions of explosives were exposed to natural and artificial sunlight. Degradation of the explosives over time was then quantified using negative chemical ionization gas chromatography mass spectrometry (GC/NCI-MS). Two explosives, trinitrotoluene (TNT) and cyclotrimethylenetrinitramine (RDX), were exposed to different aqueous environments and light exposures with salinities ranging from freshwater to twice the salinity of ocean water. Solutions were then aged for up to 6 months to simulate different conditions the explosives may be recovered from. Salinity was found to have a negligible impact on the degradation of both RDX and TNT. RDX was stable in solutions of all salinities while TNT solutions degraded regardless of salinity. Solutions of varying salinities were also exposed to UV light, where accelerated degradation was seen for both explosives. Potential degradation products of TNT were identified using electrospray ionization mass spectrometry (ESI-MS), and correspond to proposed degradation products discussed in previously published works [1]. Published by Elsevier Ireland Ltd.

Balanced versus chloride-rich solutions for fluid resuscitation in brain-injured patients: a randomised double-blind pilot study

PubMed Central

2013-01-01

Introduction We sought to investigate whether the use of balanced solutions reduces the incidence of hyperchloraemic acidosis without increasing the risk for intracranial hypertension in patients with severe brain injury. Methods We conducted a single-centre, two-arm, randomised, double-blind, pilot controlled trial in Nantes, France. Patients with severe traumatic brain injury (Glasgow Coma Scale score ≤8) or subarachnoid haemorrhage (World Federation of Neurosurgical Society grade III or higher) who were mechanically ventilated were randomised within the first 12 hours after brain injury to receive either isotonic balanced solutions (crystalloid and hydroxyethyl starch; balanced group) or isotonic sodium chloride solutions (crystalloid and hydroxyethyl starch; saline group) for 48 hours. The primary endpoint was the occurrence of hyperchloraemic metabolic acidosis within 48 hours. Results Forty-two patients were included, of whom one patient in each group was excluded (one consent withdrawn and one use of forbidden therapy). Nineteen patients (95%) in the saline group and thirteen (65%) in the balanced group presented with hyperchloraemic acidosis within the first 48 hours (hazard ratio = 0.28, 95% confidence interval [CI] = 0.11 to 0.70; P = 0.006). In the saline group, pH (P = .004) and strong ion deficit (P = 0.047) were lower and chloraemia was higher (P = 0.002) than in the balanced group. Intracranial pressure was not different between the study groups (mean difference 4 mmHg [-1;8]; P = 0.088). Seven patients (35%) in the saline group and eight (40%) in the balanced group developed intracranial hypertension (P = 0.744). Three patients (14%) in the saline group and five (25%) in the balanced group died (P = 0.387). Conclusions This study provides evidence that balanced solutions reduce the incidence of hyperchloraemic acidosis in brain-injured patients compared to saline solutions. Even if the study was not powered sufficiently for this endpoint

Effect of proton pump inhibitors on gastric juice volume, gastric pH and gastric intramucosal pH in critically ill patients : a randomized, double-blind, placebo-controlled study.

PubMed

Gursoy, Olcay; Memiş, Dilek; Sut, Necdet

2008-01-01

This study aimed to determine the effect of administration of a single-dose proton pump inhibitor (PPI) on gastric intramucosal pH (pHi), gastric juice volume and gastric pH in critically ill patients. This prospective, randomized, double-blind, placebo-controlled study included 75 patients who were divided into five groups that received the following treatment: group C (n = 15), saline 100 mL; group O (n = 15), omeprazole 20 mg; group P (n = 15), pantoprazole 40 mg; group E (n = 15), esomeprazole 20 mg; and group R (n = 15), rabeprazole 20 mg. All treatments were administered nasogastrically in 100 mL of physiological saline. Measurements of gastric pHi, gastric juice volume and gastric pH were obtained immediately before and 2, 4 and 6 hours after administration of treatments. In addition, gastric content was aspirated and its volume was recorded. Initial gastric pHi, gastric juice volume and gastric pH values were not statistically significantly different among the groups (p > 0.05). No statistically significant difference in gastric pHi was seen among the groups before or 2, 4 or 6 hours after saline or PPI administration. At hours 2, 4 and 6, gastric pH in the pantoprazole, esomeprazole and rabeprazole groups increased significantly, whereas gastric juice volume decreased significantly, compared with the omeprazole and placebo groups (p < 0.001). No statistically significant differences were seen between the pantoprazole, esomeprazole and rabeprazole groups. This is the first study to show that single-dose pantoprazole, esomeprazole and rabeprazole are associated with greater gastric pH increase and greater gastric juice volume decrease than omeprazole in critically ill patients. Our study also suggests that PPIs do not affect gastric pHi measurements in critically ill patients and can be administered during pH monitoring.

The effect of pH and concentration upon aggregation transitions in aqueous solutions of poloxamine T701.

PubMed

Armstrong, J K; Chowdhry, B Z; Snowden, M J; Dong, J; Leharne, S A

2001-10-23

Thermally induced aggregation transitions have been investigated for aqueous solutions of the poloxamine block copolymer T701-(OE(4)OP(13))(2)NCH(2)CH(2)N(OP(13)OE(4))(2)-using differential scanning calorimetry. The calorimetric signals obtained were fitted to a mass action model description of aggregation using a previously reported analytical procedure (Patterson et al., Langmuir 13 (1997) 2219). The presence of a central ethylene diamine moiety in the molecular structure renders the T701 molecule basic; this was confirmed and measured by acid/base titration. Basicity is shown to have an important impact upon aggregation. At low pH (2.5), the poloxamine exists in its protonated form and the bulk solution proton concentration is sufficient to suppress de-protonation, aggregation-as a consequence-is shifted to a higher temperature range. Any increase in pH reduces the temperature range over which aggregation occurs. The derived experimental calorimetric parameters, obtained from model fitting procedures, can be used to compute the fraction of poloxamine existing in an aggregated form, at any particular temperature. The data sets obtained were interpolated to show that at human body temperature (310.6 K) the fraction of poloxamine found in its aggregated form is zero at a pH of 2.5. However at a pH of 6.8, the percentage aggregation increases to about 85%. These aggregation characteristics of T701 have important implications for the design of drug delivery systems, which incorporate poloxamines.

AFM and SFG studies of pHEMA-based hydrogel contact lens surfaces in saline solution: adhesion, friction, and the presence of non-crosslinked polymer chains at the surface.

PubMed

Kim, Seong Han; Opdahl, Aric; Marmo, Chris; Somorjai, Gabor A

2002-04-01

The surfaces of two types of soft contact lenses neutral and ionic hydrogels--were characterized by atomic force microscopy (AFM) and sum-frequency-generation (SFG) vibrational spectroscopy. AFM measurements in saline solution showed that the presence of ionic functional groups at the surface lowered the friction and adhesion to a hydrophobic polystyrene tip. This was attributed to the specific interactions of water and the molecular orientation of hydrogel chains at the surface. Friction and adhesion behavior also revealed the presence of domains of non-crosslinked polymer chains at the lens surface. SFG showed that the lens surface became partially dehydrated upon exposure to air. On this partially dehydrated lens surface, the non-crosslinked domains exhibited low friction and adhesion in AFM. Fully hydrated in saline solution, the non-crosslinked domains extended more than tens of nanometers into solution and were mobile.

Extracting renewable energy from a salinity difference using a capacitor.

PubMed

Brogioli, Doriano

2009-07-31

Completely renewable energy can be produced by using water solutions of different salinity, like river water and sea water. Many different methods are already known, but development is still at prototype stage. Here I report a novel method, based on electric double-layer capacitor technology. Two porous electrodes, immersed in the salt solution, constitute a capacitor. It is first charged, then the salt solution is brought into contact with fresh water. The electrostatic energy increases as the salt concentration of the solution is reduced due to diffusion. This device can be used to turn sources of salinity difference into completely renewable sources of energy. An experimental demonstration is given, and performances and possible improvements are discussed.

Glutathione Complex Formation With Mercury(Ii) in Aqueous Solution at Physiological Ph

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

Mah, V.; Jalilehvand, F.; /SLAC

2012-08-23

The mercury(II) complexes formed in neutral aqueous solution with glutathione (GSH, here denoted AH{sub 3} in its triprotonated form) were studied using Hg L{sub III}-edge extended X-ray absorption fine structure (EXAFS) and {sup 199}Hg NMR spectroscopy, complemented with electrospray ionization mass spectrometric (ESI-MS) analyses. The [Hg(AH){sub 2}]{sup 2-} complex, with the Hg-S bond distances at 2.325 {+-} 0.01 {angstrom} in linear S-Hg-S coordination, and the {sup 199}Hg NMR chemical shift at -984 ppm, dominates except at high excess of glutathione. In a series of solutions with C{sub Hg(II)} {approx} 17 mM and GSH/Hg(II) mole ratios rising from 2.4 to 11.8,more » the gradually increasing mean Hg-S bond distance corresponds to an increasing amount of the [Hg(AH){sub 3}]{sup 4-} complex. ESI-MS peaks appear at -m/z values of 1208 and 1230 corresponding to the [Na{sub 4}Hg(AH){sub 2}(A)]{sup -} and [Na{sub 5}Hg(AH)(A){sub 2}]{sup -} species, respectively. In another series of solutions at pH 7.0 with CHg(II) 50 mM and GSH/Hg(II) ratios from 2.0 to 10.0, the Hg L{sub III}-edge EXAFS and {sup 199}Hg NMR spectra show that at high excess of glutathione (0.35 M) about 70% of the total mercury(II) concentration is present as the [Hg(AH){sub 3}]4- complex, with the average Hg-S bond distance 2.42 {+-} 0.02 {angstrom} in trigonal HgS{sub 3} coordination. The proportions of HgSn species, n = 2, 3, and 4, quantified by fitting linear combinations of model EXAFS oscillations to the experimental EXAFS data in our present and previous studies were used to obtain stability constants for the [Hg(AH){sub 3}]{sup 4-} complex and also for the [Hg(A){sub 4}]{sup 10-} complex that is present at high pH. For Hg(II) in low concentration at physiological conditions (pH 7.4, C{sub GSH} = 2.2 mM), the relative amounts of the HgS{sub 2} species [Hg(AH){sub 2}]{sup 2-}, [Hg(AH)(A)]{sup 3-}, and the HgS{sub 3} complex [Hg(AH){sub 3}]{sup 4-} were calculated to be 95:2:3. Our results are

Soil solution interactions may limit Pb remediation using P ...

EPA Pesticide Factsheets

Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg-1 was amended in a laboratory study with bone meal and triple super phosphate (TSP) at 5:1 P:Pb molar ratios. Soil was acidified, neturalized and re-acidified to encourage Pb phosphate formation. PRSTM-probes were used to evaluate changes in soil solution chemistry. Soil acidification did not decrease in vitro bioaccessible (IVBA) Pb using either a pH 1.5, 0.4 M glycine solution or a pH 2.5 solution with organic acids. PRSTM-probe data found soluble Pb increased 10-fold in acidic conditions compared to circumnetural pH conditions. In acidic conditions (p = 3-4), TSP treated soils increased detected P 10-fold over untreated soils. Bone meal application did not increase PRSTM-probe detected P, indicating there may have been insufficient P to react with Pb. X-ray absorption spectroscopy suggested a 10% increase in pyromorphite formation for the TSP treated soil only. Treatments increased soil electrical conductivity above 16 mS cm-1, potentially causing a new salinity hazard. This study used a novel approach by combining the human ingestion endpoint, PRSTM-probes, and X-ray absorption spectroscopy to evaluate treatment efficacy. PRSTM-probe data indicated potentially excess Ca relative to P across incubation steps that could have competed with Pb for soluble P. Mor

Identification of Trans-4-Hydroxy-L-Proline as a Compatible Solute and Its Biosynthesis and Molecular Characterization in Halobacillus halophilus.

PubMed

Kim, Kyung Hyun; Jia, Baolei; Jeon, Che Ok

2017-01-01

Halobacillus halophilus , a moderately halophilic bacterium, accumulates a variety of compatible solutes including glycine betaine, glutamate, glutamine, proline, and ectoine to cope with osmotic stress. Non-targeted analysis of intracellular organic compounds using 1 H-NMR showed that a large amount of trans-4-hydroxy-L-proline (Hyp), which has not been reported as a compatible solute in H. halophilus , was accumulated in response to high NaCl salinity, suggesting that Hyp may be an important compatible solute in H. halophilus . Candidate genes encoding proline 4-hydroxylase (PH-4), which hydroxylates L-proline to generate Hyp, were retrieved from the genome of H. halophilus through domain searches based on the sequences of known PH-4 proteins. A gene, HBHAL_RS11735, which was annotated as a multidrug DMT transporter permease in GenBank, was identified as the PH-4 gene through protein expression analysis in Escherichia coli . The PH-4 gene constituted a transcriptional unit with a promoter and a rho-independent terminator, and it was distantly located from the proline biosynthetic gene cluster ( pro operon). Transcriptional analysis showed that PH-4 gene expression was NaCl concentration-dependent, and was specifically induced by chloride anion, similar to the pro operon. Accumulation of intracellular Hyp was also observed in other bacteria, suggesting that Hyp may be a widespread compatible solute in halophilic and halotolerant bacteria.

Identification of Trans-4-Hydroxy-L-Proline as a Compatible Solute and Its Biosynthesis and Molecular Characterization in Halobacillus halophilus

PubMed Central

Kim, Kyung Hyun; Jia, Baolei; Jeon, Che Ok

2017-01-01

Halobacillus halophilus, a moderately halophilic bacterium, accumulates a variety of compatible solutes including glycine betaine, glutamate, glutamine, proline, and ectoine to cope with osmotic stress. Non-targeted analysis of intracellular organic compounds using 1H-NMR showed that a large amount of trans-4-hydroxy-L-proline (Hyp), which has not been reported as a compatible solute in H. halophilus, was accumulated in response to high NaCl salinity, suggesting that Hyp may be an important compatible solute in H. halophilus. Candidate genes encoding proline 4-hydroxylase (PH-4), which hydroxylates L-proline to generate Hyp, were retrieved from the genome of H. halophilus through domain searches based on the sequences of known PH-4 proteins. A gene, HBHAL_RS11735, which was annotated as a multidrug DMT transporter permease in GenBank, was identified as the PH-4 gene through protein expression analysis in Escherichia coli. The PH-4 gene constituted a transcriptional unit with a promoter and a rho-independent terminator, and it was distantly located from the proline biosynthetic gene cluster (pro operon). Transcriptional analysis showed that PH-4 gene expression was NaCl concentration-dependent, and was specifically induced by chloride anion, similar to the pro operon. Accumulation of intracellular Hyp was also observed in other bacteria, suggesting that Hyp may be a widespread compatible solute in halophilic and halotolerant bacteria. PMID:29104571

Effect of reclamation of abandoned salinized farmland on soil bacterial communities in arid northwest China.

PubMed

Cheng, Zhibo; Chen, Yun; Zhang, Fenghua

2018-07-15

Understanding the impact of reclamation of abandoned salinized farmland on soil bacterial community is of great importance for maintaining soil health and sustainability in arid regions. In this study, we used field sampling and 454 pyrosequencing methods to investigate the effects of 5-year reclamation treatments on soil properties, bacterial community composition and diversity. The four reclamation treatments are: abandoned salinized farmland (CK), cropland (CL), grassland (GL) and woodland (WL). We have found soil properties are significantly altered by abandoned salinized farmland reclamation. In particular, the lowest soil pH and electrical conductivity (EC) values are observed in CL (P<0.05). The dominant phyla are Firmicutes, Proteobacteria, Chloroflexi, Actinobacteria and Acidobacteria in all treatments. At the genus levels, the relative abundance of Bacillus, Lactococcus, Streptococcus and Enterococcus in CK, GL and WL is significantly higher than in CL. Bacterial diversity indices (i.e. ACE, Chao and Shannon) dramatically increase after the reclamation, with the highest in CL. Similar patterns of bacterial communities have been observed in CK, GL and WL soils, but significantly different from CL. Regression analyses indicate that the relative abundance of these phyla are significantly correlated with soil Fe, pH and EC. Results from non-metric multidimensional scaling (NMDS) and redundancy analysis (RDA) indicate that soil Fe content, EC and pH are the most important factors in shaping soil bacterial communities. Overall, results indicate that abandoned salinized farmland reclaimed for CL significantly decrease soil pH and EC, and increase soil bacterial community diversity. Soil Fe concentration, EC and pH are the dominant environmental factors affecting soil bacterial community composition. The important role of Fe concentration in shaping bacterial community composition is a new discovery among the similar studies. Copyright © 2018. Published by

Molecular mechanism of plasma sterilization in solution with the reduced pH method: importance of permeation of HOO radicals into the cell membrane

NASA Astrophysics Data System (ADS)

Takai, Eisuke; Ikawa, Satoshi; Kitano, Katsuhisa; Kuwabara, Junpei; Shiraki, Kentaro

2013-07-01

Sterilization of certain infected areas of the human body surface is necessary for dental and surgical therapies. Because the blood is filled with body fluid, sterilization in solution is essential. In vitro solution sterilization has been successively carried out using a combination of low-temperature atmospheric-pressure plasma and the reduced pH method, where the solution is sufficiently acidic. Here, we show the molecular mechanism of such plasma sterilization in solution based on microbiology. Three kinds of bacteria were inactivated by plasma treatment under various pH conditions. The theoretical and experimental models revealed that the sterilization was characterized by the concentration of hydroperoxy radicals (HOO·), which were dependent on the pH value. Bacterial inactivation rates were proportional to the HOO· concentrations calculated by the theoretical model. To evaluate the penetration of radicals into the cell membrane, a bacterial model using dye-included micelles was used. Decolouration rates of the model were also in proportion with the calculated HOO· concentrations. These results indicate that the key species for plasma sterilization were hydroperoxy radicals. More importantly, the high permeation of hydroperoxy radicals into the cell membrane plays a key role for efficient bactericidal inactivation using the reduced pH method.

Stability of a novel corticosteroid nasal irrigation solution: betamethasone 17-valerate added to extemporaneously prepared nasal irrigation solutions.

PubMed

Ong, Kheng Yong; Lim, Wei Ching; Ooi, Shing Ming; Loh, Zhi Hui; Kong, Ming Chai; Chan, Lai Wah; Heng, Paul Wan Sia

2017-05-01

There are no commercially available nasal irrigation solutions containing corticosteroids. Instead, such preparations are extemporaneously prepared by adding existing corticosteroid formulations to nasal irrigation solutions. The stability of the corticosteroid betamethasone 17-valerate (B17V), in nasal irrigation solutions of different compositions and pH and stored under different temperatures, was studied to determine the optimal choice of solution and storage conditions. Triplicate extemporaneous preparations made with B17V were prepared by adding a predetermined volume of B17V lotion to each nasal irrigation solution: normal saline (NS), sodium bicarbonate (NaHCO 3 ) powder dissolved in tap water, and a commercially available powder mixture (FLO Sinus Care Powder), dissolved in tap water or pre-boiled tap water. Preparations were stored at 30°C and 4°C. Sampling was carried out at 0, 1, 2, 6, and 24 hours. The concentrations of B17V and its degradation compound, betamethasone 21-valerate (B21V), were determined by high-performance liquid chromatography. Preparations stored at 30°C contained a lower amount of B17V and higher amount of B21V than those stored at 4°C. B17V stability in nasal irrigation solutions decreased in the following order: NS, FLO in fresh tap water, FLO in pre-boiled tap water, and NaHCO 3 . The degradation rate of B17V increased with higher storage temperature and higher pH. B17V is most stable when added to NS and least stable in NaHCO 3 solution. FLO solution prepared with either cooled boiled water or tap water is an alternative if administered immediately. Storage at 4°C can better preserve stability of B17V, over a period of 24 hours. © 2017 ARS-AAOA, LLC.

Influence of pH and temperature of dip-coating solution on the properties of cellulose acetate-ceramic composite membrane for ultrafiltration.

PubMed

Kaur, Harjot; Bulasara, Vijaya Kumar; Gupta, Raj Kumar

2018-09-01

Polymer-ceramic composite membranes were prepared by dip coating technique using 5 wt.% cellulose acetate (CA) solution at different temperatures (15 °C, 25 °C and 40 °C). The effect of pH (2-12) of the polymeric solution on the properties of the membranes was studied using SEM, EDAX, FTIR, gas and liquid permeation. The thickness of the polymeric layer depended on the interaction of CA solution with the surface of ceramic support. Membrane permeability decreased with increase in pH because of decrease in pore size and porosity resulting from strong interaction of the polymer layer with the ceramic support. The porosity and mean pore size of the prepared membranes were found to be 28-60% and 30-47 nm (ultrafiltration range), respectively. The optimized membrane (pH 7) was used for ultrafiltration of oil in water emulsions (100 and 200 mg/L). Oil rejection of 99.61% was obtained for 100 mg/L of oil concentration in water. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chemical Composition and Evaluation of Nicotine, Tobacco Alkaloids, pH and Selected Flavors in e-Cigarette Cartridges and Refill Solutions

PubMed Central

Lisko, Joseph G.; Tran, Hang; Stanfill, Stephen B.; Blount, Benjamin C.; Watson, Clifford H.

2015-01-01

Introduction Electronic cigarette (e-cigarette) use is increasing dramatically in developed countries, but little is known about these rapidly evolving products. This study analyzed and evaluated the chemical composition including nicotine, tobacco alkaloids, pH and flavors in 36 e-liquids brands from four manufacturers. Methods We determined the concentrations of nicotine, alkaloids, and select flavors and measured pH in solutions used in e-cigarettes. E-cigarette products were chosen based upon favorable consumer approval ratings from online review websites. Quantitative analyses were performed using strict quality assurance/quality control (QC) validated methods previously established by our lab for the measurement of nicotine, alkaloids, pH and flavors. Results Three-quarters of the products contained lower measured nicotine levels than the stated label values (6% - 42% by concentration). The pH for e-liquids ranged from 5.1 – 9.1. Minor tobacco alkaloids were found in all samples containing nicotine, and their relative concentrations varied widely among manufacturers. A number of common flavor compounds were analyzed in all e-liquids. Conclusions Free nicotine levels calculated from the measurement of pH correlated with total nicotine content. The direct correlation between the total nicotine concentration and pH suggests that the alkalinity of nicotine drives the pH of e-cigarette solutions. A higher percentage of nicotine exists in the more absorbable free form as total nicotine concentration increases. A number of products contained tobacco alkaloids at concentrations that exceed U.S. Pharmacopeia limits for impurities in nicotine used in pharmaceutical and food products. PMID:25636907

Last Glacial Maximum Salinity Reconstruction

NASA Astrophysics Data System (ADS)

Homola, K.; Spivack, A. J.

2016-12-01

It has been previously demonstrated that salinity can be reconstructed from sediment porewater. The goal of our study is to reconstruct high precision salinity during the Last Glacial Maximum (LGM). Salinity is usually determined at high precision via conductivity, which requires a larger volume of water than can be extracted from a sediment core, or via chloride titration, which yields lower than ideal precision. It has been demonstrated for water column samples that high precision density measurements can be used to determine salinity at the precision of a conductivity measurement using the equation of state of seawater. However, water column seawater has a relatively constant composition, in contrast to porewater, where variations from standard seawater composition occur. These deviations, which affect the equation of state, must be corrected for through precise measurements of each ion's concentration and knowledge of apparent partial molar density in seawater. We have developed a density-based method for determining porewater salinity that requires only 5 mL of sample, achieving density precisions of 10-6 g/mL. We have applied this method to porewater samples extracted from long cores collected along a N-S transect across the western North Atlantic (R/V Knorr cruise KN223). Density was determined to a precision of 2.3x10-6 g/mL, which translates to salinity uncertainty of 0.002 gms/kg if the effect of differences in composition is well constrained. Concentrations of anions (Cl-, and SO4-2) and cations (Na+, Mg+, Ca+2, and K+) were measured. To correct salinities at the precision required to unravel LGM Meridional Overturning Circulation, our ion precisions must be better than 0.1% for SO4-/Cl- and Mg+/Na+, and 0.4% for Ca+/Na+, and K+/Na+. Alkalinity, pH and Dissolved Inorganic Carbon of the porewater were determined to precisions better than 4% when ratioed to Cl-, and used to calculate HCO3-, and CO3-2. Apparent partial molar densities in seawater were

The effects of surface chemistry of mesoporous silica materials and solution pH on kinetics of molsidomine adsorption

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

Dolinina, E.S.; Parfenyuk, E.V., E-mail: terrakott37@mail.ru

2014-01-15

Adsorption kinetics of molsidomine on mesoporous silica material (UMS), the phenyl- (PhMS) and mercaptopropyl-functionalized (MMS) derivatives from solution with different pH and 298 K was studied. The adsorption kinetics was found to follow the pseudo-second-order kinetic model for all studied silica materials and pH. Effects of surface functional groups and pH on adsorption efficiency and kinetic adsorption parameters were investigated. At all studied pH, the highest molsidomine amount is adsorbed on PhMS due to π–π interactions and hydrogen bonding between surface groups of PhMS and molsidomine molecules. An increase of pH results in a decrease of the amounts of adsorbedmore » molsidomine onto the silica materials. Furthermore, the highest adsorption rate kinetically evaluated using a pseudo-second-order model, is observed onto UMS and it strongly depends on pH. The mechanism of the adsorption process was determined from the intraparticle diffusion and Boyd kinetic film–diffusion models. The results showed that the molsidomine adsorption on the silica materials is controlled by film diffusion. Effect of pH on the diffusion parameters is discussed. - Graphical abstract: The kinetic study showed that the k{sub 2} value, the rate constant of pseudo-second order kinetic model, is the highest for molsidomine adsorption on UMS and strongly depends on pH because it is determined by availability and accessibility of the reaction sites of the adsorbents molsidomine binding. Display Omitted - Highlights: • The adsorption capacities of UMS, PhMS and MMS were dependent on the pH. • At all studied pH, the highest molsidomine amount is adsorbed on PhMS. • The highest adsorption rate, k{sub 2}, is observed onto UMS and strongly depends on pH. • Film diffusion was the likely rate-limiting step in the adsorption process.« less

High-Sensitivity Surface-Enhanced Raman Scattering (SERS) Substrate Based on a Gold Colloid Solution with a pH Change for Detection of Trace-Level Polycyclic Aromatic Hydrocarbons in Aqueous Solution.

PubMed

Shi, Xiaofeng; Liu, Shu; Han, Xiaohong; Ma, Jun; Jiang, Yongchao; Yu, Guifeng

2015-05-01

In this study, a gold colloid solution whose parameters were optimized, and without any surfactants, was developed as a surface-enhanced Raman scattering (SERS) substrate for the detection of trace-level polycyclic aromatic hydrocarbons (PAHs). A gold colloid solution with 57 nm gold particles and pH 13 was prepared to be the SERS substrate. It had impressive enhancement that was two orders of magnitude higher than that of a gold colloid solution with 57 nm gold particles and without pH change (pH 6). Even with a compact field-based Raman spectrometer, naphthalene, phenanthrene, anthracene, fluoranthene, and pyrene were detected, with limits of detection at 6.8 nM, 3.4 nM, 1.8 nM, 0.68 nM (680 pM), and 0.44 nM (440 pM), respectively. The significant enhancement was ascribed to an electromagnetic mechanism and a charge-transfer mechanism. Quantitative analyses for these five PAHs in water were also performed. The SERS intensities of PAHs were found to have good linear dependence relations with the concentrations in low concentration. This high-sensitivity, easily prepared substrate offers a promising technology for the quantitative detection of trace-level PAHs.

Influence of Ca and pH on the uptake and effects of Cd in Folsomia candida exposed to simplified soil solutions.

PubMed

Ardestani, Masoud M; Ortiz, Maria Diez; van Gestel, Cornelis A M

2013-08-01

The present study sought to quantify the components of a biotic ligand model (BLM) for the effects of Cd on Folsomia candida (Collembola). Assuming that soil porewater is the main route of exposure and to exclude the effects of soil particles on metal availability, animals were exposed for 7 d to different Cd concentrations between 0.1 mM and 100 mM in simplified soil solutions at different Ca concentrations (0.2 mM, 0.8 mM, 3.2 mM, and 12.8 mM) or at different pH (5.0, 6.0, and 7.0). Higher Ca concentrations decreased the toxicity of Cd (adult survival) in test solutions, whereas toxicity was slightly lower at pH 7 and 6 than at pH 5, suggesting a mitigating effect of Ca and to a lesser extent pH on Cd toxicity to F. candida. Internal Cd concentrations in the animals increased with increasing exposure level but were significantly reduced by increasing Ca concentrations and were not significantly affected by pH. By using Langmuir isotherms, binding constants for Cd, Ca, and protons and the fraction of binding sites occupied by Cd were calculated and used to predict effects of Cd on survival. Predicted toxicity showed a good agreement with measured responses when Ca and pH were used as separate factors or combined together. The present study shows indications of protective effects of Ca but less of protons on the toxicity and uptake of Cd in F. candida on exposure to simplified soil solutions, which can be described using the principles of a biotic ligand model. Copyright © 2013 SETAC.

The effects of magnetic fields exposure on relative permittivity of saline solutions measured by a high resolution SPR system

PubMed Central

Jiang, Li; Zhao, Xinyuan; Fei, Yue; Yu, Dongdong; Qian, Jun; Tong, Jinguang; Chen, Guangdi; He, Sailing

2016-01-01

A measurement system for the relative permittivity of a physiological solution under 50 Hz magnetic fields (MF) is presented. It is based on a phase-sensitive surface plasmon resonance (SPR) system. Relative permittivity was analyzed for different solute concentrations of sodium chloride under various MF exposure parameters. We found that MF exposure at 0.2–4.0 mT step-wise decreased significantly the SPR phase signal of a 0.9% sodium chloride solution while 0.1 mT of MF exposure did not. The decreases in the SPR phase signal depended on the duration of MF exposure, and the signal reached a plateau after 15 min of exposure. Interestingly, the decreased SPR phase signal showed a gradual increase and approached the background level when the exposure was drawn off. In addition, we found that the response of the sodium chloride solution to MF also depended on its concentration. In brief, the relative permittivity of sodium chloride in solutions appears to be practically affected by 50 Hz MF exposure. Our data indicates that the relative permittivity of the saline solution influenced by MF exposure should be considered when investigating the biological effects of MF exposure on organisms in experimental study. PMID:27121618

Three dimensional graphene transistor for ultra-sensitive pH sensing directly in biological media.

PubMed

Ameri, Shideh Kabiri; Singh, Pramod K; Sonkusale, Sameer R

2016-08-31

In this work, pH sensing directly in biological media using three dimensional liquid gated graphene transistors is presented. The sensor is made of suspended network of graphene coated all around with thin layer of hafnium oxide (HfO2), showing high sensitivity and sensing beyond the Debye-screening limit. The performance of the pH sensor is validated by measuring the pH of isotonic buffered, Dulbecco's phosphate buffered saline (DPBS) solution, and of blood serum derived from Sprague-Dawley rat. The pH sensor shows high sensitivity of 71 ± 7 mV/pH even in high ionic strength media with molarities as high as 289 ± 1 mM. High sensitivity of this device is owing to suspension of three dimensional graphene in electrolyte which provides all around liquid gating of graphene, leading to higher electrostatic coupling efficiency of electrolyte to the channel and higher gating control of transistor channel by ions in the electrolyte. Coating graphene with hafnium oxide film (HfO2) provides binding sites for hydrogen ions, which results in higher sensitivity and sensing beyond the Debye-screening limit. The 3D graphene transistor offers the possibility of real-time pH measurement in biological media without the need for desaltation or sample preparation. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of pH on Cr(VI) ions removal from aqueous solutions using carboxymethyl cellulose-based hydrogel as adsorbent

NASA Astrophysics Data System (ADS)

Anah, L.; Astrini, N.

2017-03-01

The major problem in heavy metal pollution is that these metals are not biodegradable and accordingly accumulate in the bodies of living organisms, causing dangerous diseases and serious cell disorder. According to World Health Organization (WHO), the long term exposure of Cr(VI) levels of over 0.1 ppm causes respiratory problems, liver and kidney damage, and carcinogenicity.Due to its easy operation and of various cheap adsorbents development, adsorption has been proved to be efficient and most economically attractive technique and feasible to the removal of toxic heavy metal from wastewater. The study aimed to report the removal of Cr(VI) ions from aqueous solutions through adsorption process using carboxymethyl cellulose-graft-poly(acrylic acid) (CMC-g-PAA) hydrogel as adsorbent.Effect of pH was studied to remove hexavalent chromium.Graft copolymerization of poly(acrylic acid) onto carboxymethyl cellulose was carried out in the presence of benzoyl peroxide redox initiator and methylenbisacrylamide as crosslinker agent. Batch experiments were carried out to investigate the effects ofinitial pH.The adsorption of Cr(VI) ions as a function of pH was conducted in the initial pH range of 1 to 8. The results indicated that acidic pH strongly favored the adsorption. The optimum pH for adsorption of Cr(VI) ranged from 1 to 3, and the maximum uptake of Cr(VI) from the solution was 6.53 mg/g at pH 1 and 30°C. FTIR spectroscopy, SEM analyses were performed on the adsorbent before and after Cr(VI) binding. All analyses confirmed the complexation of Cr(VI) ions on the adsorbent.

Hyaluronic acid improves "pleasantness" and tolerability of nebulized hypertonic saline in a cohort of patients with cystic fibrosis.

PubMed

Buonpensiero, Paolo; De Gregorio, Fabiola; Sepe, Angela; Di Pasqua, Antonio; Ferri, Pasqualina; Siano, Maria; Terlizzi, Vito; Raia, Valeria

2010-11-01

Inhaled hypertonic saline improves lung function and decreases pulmonary exacerbations in people with cystic fibrosis. However, side effects such as cough, narrowing of airways and saltiness cause intolerance of the therapy in 8% of patients. The aim of our study was to compare the effect of an inhaled solution of hyaluronic acid and hypertonic saline with hypertonic solution alone on safety and tolerability. A total of 20 patients with cystic fibrosis aged 6 years and over received a single treatment regimen of 7% hypertonic saline solution or hypertonic solution with 0.1% hyaluronate for 2 days nonconsecutively after a washout period in an open crossover study. Cough, throat irritation, and salty taste were evaluated by a modified ordinal score for assessing tolerability; "pleasantness" was evaluated by a five-level, Likert-type scale. Forced expiratory volume in 1 second was registered before and after the end of the saline inhalations. All 20 patients (nine males, 11 females, mean age 13 years, range 8.9-17.7) completed the study. The inhaled solution of 0.1% hyaluronic acid and hypertonic saline significantly improved tolerability and pleasantness compared to hypertonic saline alone. No major adverse effects were observed. No difference was documented in pulmonary function tests between the two treatments. Hyaluronic acid combined with hypertonic saline solution may contribute to improved adherence to hypertonic saline therapy. Further clinical trials are needed to confirm our findings. Considering the extraordinary versatility of hyaluronic acid in biological reactions, perspective studies could define its applicability to halting progression of lung disease in cystic fibrosis.

Influence of Water Solute Exposure on the Chemical Evolution and Rheological Properties of Asphalt.

PubMed

Pang, Ling; Zhang, Xuemei; Wu, Shaopeng; Ye, Yong; Li, Yuanyuan

2018-06-11

The properties of asphalt pavement are damaged under the effects of moisture. The pH value and salt concentration of water are the key factors that affect the chemical and rheological properties of asphalt during moisture damage. Four kinds of water solutions, including distilled water, an acidic solution, alkaline solution and saline solution were used to investigate the effects of aqueous solute compositions on the chemical and rheological properties of asphalt. Thin-layer chromatography with flame ionization detection (TLC-FID), Fourier transform infrared (FTIR) spectroscopy and dynamic shear rheometer (DSR) were applied to investigate the components, chemistry and rheology characteristics of asphalt specimens before and after water solute exposure. The experimental results show that moisture damage of asphalt is not only associated with an oxidation process between asphalt with oxygen, but it is also highly dependent on some compounds of asphalt dissolving and being removed in the water solutions. In detail, after immersion in water solute, the fraction of saturates, aromatics and resins in asphalt binders decreased, while asphaltenes increased; an increase in the carbonyl and sulphoxide indices, and a decrease in the butadiene index were also found from the FTIR analyzer test. The rheological properties of asphalt are sensitive to water solute immersing. The addition of aqueous solutes causes more serious moisture damage on asphalt binders, with the pH11 solution presenting as the most destructive during water solute exposure.

The effect of pH on the corrosion behavior of intermetallic compounds Ni{sub 3}(Si,Ti) and Ni{sub 3}(Si,Ti) + 2Mo in sodium chloride solutions

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

Priyotomo, Gadang, E-mail: gada001@lipi.go.id; Nuraini, Lutviasari, E-mail: Lutviasari@gmail.com; Kaneno, Yasuyuki, E-mail: kaneno@mtr.osakafu-u.ac.id

The corrosion behavior of the intermetallic compounds, Ni{sub 3}(Si,Ti) (L1{sub 2}: single phase) and Ni{sub 3}(Si,Ti) + 2Mo (L1{sub 2} and (L12 + Ni{sub ss}) mixture region), has been investigated using an immersion test, electrochemical method and surface analytical method (SEM; scanning electron microscope and EDAX: Energy Dispersive X-ray) in 0.5 kmol/m{sup 3} NaCl solutions at various pH. The corrosion behavior of nickel alloy C-276 was studied under the same experimental conditions as a reference. It was found that the uniform attack was observed on Ni{sub 3}(Si,Ti) for the immersion test at lower pH, while the pitting attack was observedmore » on this compound for this test at neutral solution. Furthermore, Ni{sub 3}(Si,Ti)+2Mo had the preferential dissolution of L1{sub 2} compared to (L1{sub 2} + Ni{sub ss}) mixture region at lower pH, while pitting attack occurred in (L1{sub 2} + Ni{sub ss}) mixture region at neutral solution. For both intermetallic compounds, the magnitude of pitting and uniform attack decrease with increasing pH of solutions. From the immersion test and polarization curves, the corrosion resistance of Ni{sub 3}(Si,Ti)+2Mo is lower than that of Ni{sub 3}(Si,Ti), while the nickel alloy C-276 is the highest one at various pH of solutions. On the other hand, in the lower pH of solutions, the corrosion resistance of tested materials decreased significantly compared to those in neutral and higher pH of solutions.« less

pH controls spermatozoa motility in the Pacific oyster (Crassostrea gigas)

PubMed Central

Suquet, Marc; Malo, Florent; Queau, Isabelle; Pignet, Patricia; Ratiskol, Dominique; Le Grand, Jacqueline; Huber, Matthias; Cosson, Jacky

2018-01-01

ABSTRACT Investigating the roles of chemical factors stimulating and inhibiting sperm motility is required to understand the mechanisms of spermatozoa movement. In this study, we described the composition of the seminal fluid (osmotic pressure, pH, and ions) and investigated the roles of these factors and salinity in initiating spermatozoa movement in the Pacific oyster, Crassostrea gigas. The acidic pH of the gonad (5.82±0.22) maintained sperm in the quiescent stage and initiation of flagellar movement was triggered by a sudden increase of spermatozoa external pH (pHe) when released in seawater (SW). At pH 6.4, percentage of motile spermatozoa was three times higher when they were activated in SW containing 30 mM NH4Cl, which alkalinizes internal pH (pHi) of spermatozoa, compared to NH4Cl-free SW, revealing the role of pHi in triggering sperm movement. Percentage of motile spermatozoa activated in Na+-free artificial seawater (ASW) was highly reduced compared to ASW, suggesting that change of pHi triggering sperm motility was mediated by a Na+/H+ exchanger. Motility and swimming speed were highest in salinities between 33.8 and 42.7‰ (within a range of 0 to 50 ‰), and pH values above 7.5 (within a range of 4.5 to 9.5). PMID:29483075

Effect of chitosan on the heat stability of whey protein solution as a function of pH.

PubMed

Zhao, Zhengtao; Xiao, Qian

2017-03-01

Chitosan was reported to interact with proteins through electrostatic interactions. Their interaction was influenced by pH, which was not fully characterized. Further research on the interactions between protein and chitosan at different pH and their influence on the thermal denaturation of proteins is necessary. In this research, the effect of chitosan on the heat stability of whey protein solution at pH 4.0-6.0 was studied. At pH 4.0, a small amount chitosan was able to prevent the heat-induced denaturation and aggregation of whey protein molecules. At higher pH values (5.5 and 6.0), whey proteins complexed with chitosan through electrostatic attraction. The formation of chitosan-whey protein complexes at pH 5.5 improved the heat stability of dispersions and no precipitation could be detected up to 20 days. The dispersion with a medium amount of chitosan (chitosan:whey protein 1:5) produced the most stable particles, which had an average radius of 135 ± 14 nm and a zeta potential value of 36 ± 1 mV. In contrast, at pH 6.0 only the dispersion with a high amount of chitosan (chitosan:whey protein 1:2) showed good shelf stability up to 20 days. It was possible to produce heat-stable whey protein beverages by regulating the interaction between chitosan and whey protein molecules. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Saline as a vehicle control does not alter ventilation in male CD-1 mice.

PubMed

Receno, Candace N; Glausen, Taylor G; DeRuisseau, Lara R

2018-05-01

Saline (0.9% NaCl) is used in clinical and research settings as a vehicle for intravenous drug administration. While saline is a standard control in mouse studies, there are reports of hyperchloremic metabolic acidosis in high doses. It remains unknown if metabolic acidosis occurs in mice and/or if compensatory increases in breathing frequency and tidal volume accompany saline administration. It was hypothesized that saline administration alters blood pH and the pattern of breathing in conscious CD-1 male mice exposed to air or hypoxia (10% O 2 , balanced N 2 ). Unrestrained barometric plethysmography was used to quantify breathing frequency (breaths/min; bpm), tidal volume (VT; mL/breath/10 g body weight (BW)), and minute ventilation (VE; mL/min/10 g BW) in two designs: (1) 11-week-old mice with no saline exposure (n = 11) compared to mice with 7 days of 0.9% saline administration (intraperitoneal, i.p.; 10 mL/kg body mass; n = 6). and (2) 17-week-old mice tested before (PRE) and after 1 day (POST1, n = 6) or 7 days (POST7, n = 5) of saline (i.p.; 10 mL/kg body mass). There were no differences when comparing frequency, VT, or VE between groups for either design with room air or hypoxia exposures. Hypoxia increased frequency, VT, and VE compared to room air. Moreover, conscious blood sampling showed no differences in pH, p a CO 2 , p aO2 , or HCO3- in mice without or with 7 days of saline. These findings reveal no differences in ventilation following 1 and/or 7 days of saline administration in mice. Therefore, the use of 0.9% saline as a control is supported for studies evaluating the control of breathing in mice. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Passivation Characteristics of Alloy Corrosion-Resistant Steel Cr10Mo1 in Simulating Concrete Pore Solutions: Combination Effects of pH and Chloride

PubMed Central

Ai, Zhiyong; Sun, Wei; Jiang, Jinyang; Song, Dan; Ma, Han; Zhang, Jianchun; Wang, Danqian

2016-01-01

The electrochemical behaviour for passivation of new alloy corrosion-resistant steel Cr10Mo1 immersed in alkaline solutions with different pH values (13.3, 12.0, 10.5, and 9.0) and chloride contents (0.2 M and 1.0 M), was investigated by various electrochemical techniques: linear polarization resistance, electrochemical impedance spectroscopy and capacitance measurements. The chemical composition and structure of passive films were determined by XPS. The morphological features and surface composition of the immersed steel were evaluated by SEM together with EDS chemical analysis. The results evidence that pH plays an important role in the passivation of the corrosion-resistant steel and the effect is highly dependent upon the chloride contents. In solutions with low chloride (0.2 M), the corrosion-resistant steel has notably enhanced passivity with pH falling from 13.3 to 9.0, but does conversely when in presence of high chloride (1.0 M). The passive film on the corrosion-resistant steel presents a bilayer structure: an outer layer enriched in Fe oxides and hydroxides, and an inner layer, rich in Cr species. The film composition varies with pH values and chloride contents. As the pH drops, more Cr oxides are enriched in the film while Fe oxides gradually decompose. Increasing chloride promotes Cr oxides and Fe oxides to transform into their hydroxides with little protection, and this is more significant at lower pH (10.5 and 9.0). These changes annotate passivation characteristics of the corrosion-resistant steel in the solutions of different electrolyte. PMID:28773867

Passivation Characteristics of Alloy Corrosion-Resistant Steel Cr10Mo1 in Simulating Concrete Pore Solutions: Combination Effects of pH and Chloride.

PubMed

Ai, Zhiyong; Sun, Wei; Jiang, Jinyang; Song, Dan; Ma, Han; Zhang, Jianchun; Wang, Danqian

2016-09-01

The electrochemical behaviour for passivation of new alloy corrosion-resistant steel Cr10Mo1 immersed in alkaline solutions with different pH values (13.3, 12.0, 10.5, and 9.0) and chloride contents (0.2 M and 1.0 M), was investigated by various electrochemical techniques: linear polarization resistance, electrochemical impedance spectroscopy and capacitance measurements. The chemical composition and structure of passive films were determined by XPS. The morphological features and surface composition of the immersed steel were evaluated by SEM together with EDS chemical analysis. The results evidence that pH plays an important role in the passivation of the corrosion-resistant steel and the effect is highly dependent upon the chloride contents. In solutions with low chloride (0.2 M), the corrosion-resistant steel has notably enhanced passivity with pH falling from 13.3 to 9.0, but does conversely when in presence of high chloride (1.0 M). The passive film on the corrosion-resistant steel presents a bilayer structure: an outer layer enriched in Fe oxides and hydroxides, and an inner layer, rich in Cr species. The film composition varies with pH values and chloride contents. As the pH drops, more Cr oxides are enriched in the film while Fe oxides gradually decompose. Increasing chloride promotes Cr oxides and Fe oxides to transform into their hydroxides with little protection, and this is more significant at lower pH (10.5 and 9.0). These changes annotate passivation characteristics of the corrosion-resistant steel in the solutions of different electrolyte.

Treatment of high salinity brines by direct contact membrane distillation: Effect of membrane characteristics and salinity.

PubMed

Li, Jianfeng; Guan, Yunshan; Cheng, Fangqin; Liu, Yu

2015-12-01

Direct contact membrane distillation (DCMD) is one of the attractive technologies for high salinity brine treatment. In this study, four polytetrafluoroethylene (PTFE) membranes were examined in treating highly concentrated salt solutions. Results showed that non-supported membranes generally have a higher overall mass transfer coefficient but porosity seems to be the most important parameter controlling membrane flux and thermal efficiency. Supported membranes with large thickness had relatively higher thermal efficiency than small thickness. This can be attributed to their reduced heat loss through heat condition. In addition, KCl, NaCl and MgCl2 solutions showed distinct trends over flux decline at high salt concentrations (⩾2.0M). The difference in flux was largely due to the discrepancy in water activities of these solutions (KCl>NaCl>MgCl2). However, the effect of viscosity on permeate flux could not be neglected for MgCl2 at high salt concentrations as the suddenly increased viscosity could lead to serious temperature polarization. This study indicates that membrane distillation is a promising technology for high salinity brine treatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Soil solution Zn and pH dynamics in non-rhizosphere soil and in the rhizosphere of Thlaspi caerulescens grown in a Zn/Cd-contaminated soil.

PubMed

Luo, Y M; Christie, P; Baker, A J

2000-07-01

Temporal changes in soil solution properties and metal speciation were studied in non-rhizosphere soil and in the rhizosphere of the hyperaccumulator Thlaspi caerulescens J. & C. Presl (population from Prayon, Belgium) grown in a Zn- and Cd-contaminated soil. This paper focuses on soil solution Zn and pH dynamics during phytoextraction. The concentration of Zn in both non-rhizosphere and rhizosphere soil solutions decreased from 23 mg/l at the beginning to 2 mg/l at the end of the experiment (84 days after transplanting of seedlings), mainly due to chemical sorption. There was no significant difference in overall Zn concentration between the planted and the unplanted soil solutions (P > 0.05). Soil solution pH decreased initially and then increased slightly in both planted and unplanted soil zones. From 60 to 84 days after transplanting, the pH of the rhizosphere soil solution was higher than that of non-rhizosphere soil solution (P<0.05). Zn uptake by the hyperaccumulator plants was 8.8 mg per pot (each containing 1 kg oven-dry soil) on average. The data indicate that the potential of T. caerulescens to remove Zn from contaminated soil may not be related to acidification of the rhizosphere.

Influence of the solution pH in the 6-mercaptopurine self-assembled monolayer (6MP-SAM) on a Au(111) single-crystal electrode.

PubMed

Madueño, Rafael; García-Raya, Daniel; Viudez, Alfonso J; Sevilla, José M; Pineda, Teresa; Blázquez, Manuel

2007-10-23

Self-assembled monolayers (SAMs) of 6-mercaptopurine (6MP) have been prepared on a Au(111) single-crystal electrode by immersion of the metal surface in a 100 microM 6MP and 0.01 M HClO4 solution. The 6MP-SAM Au(111) single-crystal electrodes were transferred to the cell and allowed to equilibrate with the different aqueous working solutions before the electrochemical experiments. The influence of the solution pH was studied by cyclic voltammetry, double layer capacitance curves, and electrochemical impedance spectroscopy. The electrochemical behavior of the 6MP-SAM in acetic acid at pH 4 presents important differences in comparison to that obtained in 0.1 M KOH solutions. Cyclic voltammograms for the reductive desorption process in acid medium are broad and show some features that can be explained by a phase transition between a chemisorbed and a physisorbed state of the 6MP molecules. The low solubility of these molecules in acid medium could explain this phenomenon and the readsorption of the complete monolayer when the potential is scanned in the positive direction. The variation of the double-layer capacitance values in the potential range of monolayer stability with the pH suggests that the acid-base chemistry of the 6MP molecules is playing a role. This fact has been studied by following the variations of the electron-transfer rate constant of the highly charged redox probes as are Fe(CN)(6)-3/-4 and Ru(NH3)(6)+3/+2 as a function of solution pH. The apparent surface pKa value for the 6MP-SAM (pKa approximately 8) is explained by the total conversion of the different 6MP tautomers that exist in solution to the thiol species in the adsorbed state.

Investigation of Lake Water Salinity by Using Four-Band Salinity Algorithm on WorldView-2 Satellite Image for a Saline Industrial Lake

NASA Astrophysics Data System (ADS)

Budakoǧlu, Murat; Karaman, Muhittin; Damla Uça Avcı, Z.; Kumral, Mustafa; Geredeli (Yılmaz), Serpil

2014-05-01

Salinity of a lake is an important characteristic since, these are potentially industrial lakes and the degree of salinity can significantly be used for determination of mineral resources and for the production management. In the literature, there are many studies of using satellite data for salinity related lake studies such as determination of salinity distribution and detection of potential freshwater sources in less salt concentrated regions. As the study area Lake Acigol, located in Denizli (Turkey) was selected. With it's saline environment, it's the major sodium sulphate production resource of Turkey. In this study, remote sensing data and data from a field study was used and correlated. Remote sensing is an efficient tool to monitor and analyze lake properties by using it complementary to field data. Worldview-2 satellite data was used in this study which consists of 8 bands. At the same time with the satellite data acquisition, a field study was conducted to collect the salinity values in 17 points of the laker with using YSI 556 Multiparametre for measurements. The values were measured as salinity amount in grams per kilogram solution and obtained as ppt unit. It was observed that the values vary from 34 ppt - 40.1 ppt and the average is 38.056 ppt. In Thalassic serie, the lake was in mixoeuhaline state in the time of issue. As a first step, ATCOR correction was performed on satellite image for atmospheric correction. There were some clouds on the lake field, hence it was decided to continue the study by using the 12 sampling points which were clear on the image. Then, for each sampling point, a spectral value was obtained by calculating the average at a 11*11 neighborhood. The relation between the spectral reflectance values and the salinity was investigated. The 4-band algorithm, which was used for determination of chlorophyll-a distribution in highly turbid coastal environment by Wei (2012) was applied. Salinity α (Λi-1 / Λj-1) * (Λk-1 / Λm-1) (i

Modeling as a tool for management of saline soils and irrigation waters

USDA-ARS?s Scientific Manuscript database

Optimal management of saline soils and irrigation waters requires consideration of many interrelated factors including, climate, water applications and timing, water flow, plant water uptake, soil chemical reactions, plant response to salinity and solution composition, soil hydraulic properties and ...

Enhancement of nitrate uptake and growth of barley seedlings by calcium under saline conditions

NASA Technical Reports Server (NTRS)

Ward, M. R.; Aslam, M.; Huffaker, R. C.

1986-01-01

The effect of Ca2+ on NO3- assimilation in young barley (Hordeum vulgare L. var CM 72) seedlings in the presence and absence of NaCl was studied. Calcium increased the activity of the NO3- transporter under saline conditions, but had little effect under nonsaline conditions. Calcium decreased the induction period for the NO3- transporter under both saline and nonsaline conditions but had little effect on its apparent Km for NO3- both in the presence and absence of NaCl. The enhancement of NO3- transport by Ca2+ under saline conditions was dependent on the presence of Ca2+ in the uptake solution along with the salt, since Ca2+ had no effect when supplied before or after salinity stress. Although Mn2+ and Mg2+ enhanced NO3- uptake under saline conditions, neither was as effective as Ca2+. In longer studies, increasing the Ca2+ concentration in saline nutrient solutions resulted in increases in NO3- assimilation and seedling growth.

Influence of the pH value of a colloidal gold solution on the absorption spectra of an LSPR-assisted sensor

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

Zhu, Jin; Li, Wenbin; Zhu, Mao

2014-03-15

The localized surface plasmon resonances (LSPRs) of gold particles assembled on a crystal plate are a powerful tool for biological sensors. Here, we prepare gold colloids in different pH solutions. We monitor the effects of the particle radius and particle coverage on the absorption spectra of AT-cut (r-face dihedral angle of about 3°) crystal plates supporting gold nanoparticles. The surface morphologies were monitored on silicon dioxide substrates using ultraviolet and visible (UV-vis) spectroscopy, and atomic force microscopy (AFM). The results showed that the gold particle coverage decreases with increasing pH value of the gold colloid solution. This phenomenon demonstrates thatmore » self-assembled gold surfaces were formed via the electrostatic adsorption of gold particles on the positively charged, ionized amino groups on the crystal plates in the acidic solution. The spectrum of gold nanoparticles with different coverage degree on the crystal plates showed that the LSPR properties are highly dependent on pH.« less

Dissolution of man-made vitreous fibers in rat alveolar macrophage culture and Gamble's saline solution: influence of different media and chemical composition of the fibers.

PubMed Central

Luoto, K; Holopainen, M; Karppinen, K; Perander, M; Savolainen, K

1994-01-01

The effect of different chemical compositions of man-made vitreous fibers (MMVF) on their dissolution by alveolar macrophages (AM) in culture and in Gamble's solution was studied. The fibers were exposed to cultured rat AMs, culture medium alone; or Gamble's saline solution for 2, 4, or 8 days. The dissolution of the fibers was studied by measuring the amount of silicon (Si), iron (Fe), and aluminum (Al) in each medium. The AMs in culture dissolved Fe and Al from the fibers but the dissolution of Si was more marked in the cell culture medium without cells and in the Gamble's solution. The dissolution of Si, Fe, and Al was different for different fibers, and increased as a function of time. The Fe and Al content of the fibers correlated negatively with the dissolution of Si by AMs from the MMVF, i.e., when the content of Fe and Al of the fibers increased the dissolution of Si decreased. These results suggest that the chemical composition of MMVFs has a marked effect on their dissolution. AMs seem to affect the dissolution of Fe and Al from the fibers. This suggests that in vitro models with cells in the media rather than only culture media or saline solutions would be preferable in dissolution studies of MMVFs. PMID:7882911

Chemical Composition and Evaluation of Nicotine, Tobacco Alkaloids, pH, and Selected Flavors in E-Cigarette Cartridges and Refill Solutions.

PubMed

Lisko, Joseph G; Tran, Hang; Stanfill, Stephen B; Blount, Benjamin C; Watson, Clifford H

2015-10-01

Electronic cigarette (e-cigarette) use is increasing dramatically in developed countries, but little is known about these rapidly evolving products. This study analyzed and evaluated the chemical composition including nicotine, tobacco alkaloids, pH, and flavors in 36 e-liquids brands from 4 manufacturers. We determined the concentrations of nicotine, alkaloids, and select flavors and measured pH in solutions used in e-cigarettes. E-cigarette products were chosen based upon favorable consumer approval ratings from online review websites. Quantitative analyses were performed using strict quality assurance/quality control validated methods previously established by our lab for the measurement of nicotine, alkaloids, pH, and flavors. Three-quarters of the products contained lower measured nicotine levels than the stated label values (6%-42% by concentration). The pH for e-liquids ranged from 5.1-9.1. Minor tobacco alkaloids were found in all samples containing nicotine, and their relative concentrations varied widely among manufacturers. A number of common flavor compounds were analyzed in all e-liquids. Free nicotine levels calculated from the measurement of pH correlated with total nicotine content. The direct correlation between the total nicotine concentration and pH suggests that the alkalinity of nicotine drives the pH of e-cigarette solutions. A higher percentage of nicotine exists in the more absorbable free form as total nicotine concentration increases. A number of products contained tobacco alkaloids at concentrations that exceed U.S. pharmacopeia limits for impurities in nicotine used in pharmaceutical and food products. © Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Transient alkalinization of the leaf apoplast stiffens the cell wall during onset of chloride salinity in corn leaves.

PubMed

Geilfus, Christoph-Martin; Tenhaken, Raimund; Carpentier, Sebastien Christian

2017-11-17

During chloride salinity, the pH of the leaf apoplast (pH apo ) transiently alkalizes. There is an ongoing debate about the physiological relevance of these stress-induced pH apo changes. Using proteomic analyses of expanding leaves of corn ( Zea mays L.), we show that this transition in pH apo conveys functionality by (i) adjusting protein abundances and (ii) affecting the rheological properties of the cell wall. pH apo was monitored in planta via microscopy-based ratio imaging, and the leaf-proteomic response to the transient leaf apoplastic alkalinization was analyzed via ultra-high performance liquid chromatography-MS. This analysis identified 1459 proteins, of which 44 exhibited increased abundance specifically through the chloride-induced transient rise in pH apo These elevated protein abundances did not directly arise from high tissue concentrations of Cl - or Na + but were due to changes in the pH apo Most of these proteins functioned in growth-relevant processes and in the synthesis of cell wall-building components such as arabinose. Measurements with a linear-variable differential transducer revealed that the transient alkalinization rigidified ( i.e. stiffened) the cell wall during the onset of chloride salinity. A decrease in t -coumaric and t -ferulic acids indicates that the wall stiffening arises from cross-linkage to cell wall polymers. We conclude that the pH of the apoplast represents a dynamic factor that is mechanistically coupled to cellular responses to chloride stress. By hardening the wall, the increased pH abrogates wall loosening required for cell expansion and growth. We conclude that the transient alkalinization of the leaf apoplast is related to salinity-induced growth reduction. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Effect of the pH in the adsorption and in the immersion enthalpy of monohydroxylated phenols from aqueous solutions on activated carbons.

PubMed

Blanco-Martínez, D A; Giraldo, L; Moreno-Piraján, J C

2009-09-30

An activated carbon Carbochem--PS230 was modified by chemical and thermal treatment in flow of H(2) in order to evaluate the influence of the activated carbon chemical surface in the adsorption of the monohydroxylated phenols. The solid-solution interaction was determined by analyzing the adsorption isotherms at 298 K at pH 7, 9 and 11 during 48 h. The adsorption capacity of activated carbons increases when the pH solution decreases. The amount adsorbed increases in the reduced carbon at the maximum adsorption pH and decreases in the oxidized carbon. In the sample of granulated activated carbon, CAG, the monohydroxylated phenols adsorption capacity diminishes in the following order catechol >hydroquinone >resorcinol, at the three pH values. The experimental data are evaluated with Freundlich's and Langmuir's models. The immersion enthalpies are determined and increase with the retained amount, ranging between 21.5 and 45.7 J g(-1). In addition, the immersion enthalpies show more interaction with the reduced activated carbon that has lower total acidity contents.

A monocrystal graphene domain biosensor array with differential output for real-time monitoring of glucose and normal saline.

PubMed

Shi, Junjie; Li, Xin; Chen, Qian; Gao, Kun; Song, Hui; Guo, Shixi; Li, Quanfu; Fang, Ming; Liu, Weihua; Liu, Hongzhong; Wang, Xiaoli

2015-05-07

A biosensor array with differential output based on a monocrystal graphene domain is proposed to realize high resolution measurements. The differential output structure can eliminate the noise that comes from graphene crystal orientation and grain boundary, as well as the fluctuation that comes from the contact resistance and experiment process, so as to improve resolution in the lower concentration. We have fabricated a high quality monocrystal graphene domain that has millimeter size by the chemical vapor deposition method. Two identical graphene ribbons that are cut from the same domain are used as field effect transistor source-to-drain channels for the reference and the test of differential output, respectively. The experimental results show that the source-to-drain current has a fast response shorter than 0.5 second in glucose, normal saline and pH buffer solutions of different concentrations. Sensitivity increases exponentially with the increase of concentration of the tested liquid and the high resolution range is 0.01-2 wt% in glucose and 0.0009-0.018 wt% in saline, and the highest resolutions of glucose and saline are 0.01 wt% and 0.0009 wt%, respectively. We have fabricated a 1 × 4 array structure with differential outputs that pave the way for rapidly detecting ultra-low concentration of analytes.

On the flocculation and settling characteristics of low- and high-concentration sediment suspensions: effects of particle concentration and salinity conditions.

PubMed

Zhu, Zhongfan; Xiong, Xiangzhong; Liang, Chaohuang; Zhao, Ming

2018-05-01

It remains unclear how the primary particle concentration and salinity conditions influence the flocculation and settling characteristics of water-sediment suspensions. In this study, two sets of experiments were performed to examine the flocculation and settling properties of low- and high-concentration sediment suspensions. In low-concentration suspensions, the sediment concentration undergoes a rapid initial decrease followed by a slow decrease until it approaches zero with increasing flocculation time. Increases in salinity or the valence of cations from the saline solution added to the suspension lead to a more rapidly decreasing sediment concentration with flocculation time. The valence of cations from the saline solution has a larger influence on the flocculation-settling behaviours of the suspension than the salinity. In high-concentration sediment suspensions, the height of the clear water-turbid water interface in the water-sediment suspension experiences an initial, rapidly decreasing phase followed by a slowly decreasing phase with increasing flocculation time. Increasing the primary particle concentration, salinity or valence of cations from the saline solution added to the suspension causes the height reduction of the clear water-turbid water interface to become gentler. Finally, the valence of cations from the saline solution has a greater influence on the settling characteristics of the high-concentration water-sediment suspension than the salinity.

Distribution of Surface pH and Total Alkalinity at the Sea of Okhotsk and the East Sea in October 2007

NASA Astrophysics Data System (ADS)

Shim, J.; Kang, D.; Jin, Y.; Obzhirov, A.

2008-12-01

Surface pH, total alkalinity, temperature and salinity were measured at the Sea of Okhotsk and the East Sea (along a track from Vladivostok to the northeastern slope of Sakhalin Island through Soya Strait: 42°N, 132°E - 55°N, 145°E) in October 2007. Continuous pH measurements were conducted using an underway potentiometric pH system modified from Tishchenko et al. (2002) and discrete total alkalinity measurements were made by direct titration with hydrochloric acid. Warm saline surface waters were observed in the East Sea (from Vladivostok to Soya Strait), and relatively cold less-saline waters were observed in the Sea of Okhotsk (at the eastern slopes of Sakhalin Island). In the East Sea and the Sea of Okhotsk, surface pH ranged from 8.063 to 8.158 and 8.047 to 8.226, and total alkalinity normalized to salinity 35 ranged from 2323 to 2344 μmol kg-1 and 2367 to 2422 μmol kg-1, respectively. Due to the freshwater input from rivers and geochemical activity in the water column and sediment, the Sea of Okhotsk generally showed much wider ranges of water properties and richer in carbonate parameters than those of the East Sea. Particularly, water properties changed dramatically at the eastern slopes of Sakhalin Island; surface salinity decreased southward by about 0.5-1 psu and pH and normalized total alkalinity increased southward by about 0.05-0.1 and 20-50 μmol kg-1, respectively. Thus, pCO2 concentration calculated from pH and total alkalinity, ranged from 350-375 μatm in the north to 280-300 μatm in the south of the Okhotsk Sea. The high pH and normalized total alkalinity, and low pCO2 and salinity in the south might be the result of surface water mixing with fresh water discharge from rivers and/or the results of massive primary production along the eastern coast of Sakhalin Island. In the most study area, surface pCO2 ranged from 280 to 370 μatm and was undersaturated relative to atmosphere. Therefore, the Sea of Okhotsk and the East Sea acted as

Formation of apatitic calcium phosphates in a Na-K-phosphate solution of pH 7.4.

PubMed

Tas, A C; Aldinger, F

2005-02-01

Poorly crystalline, apatitic calcium phosphate powders have been synthesized by slowly adding a Na- and K-containing reference phosphate solution with a pH value of 7.4 to an aqueous calcium nitrate solution at 37 degrees C. Nano-particulated apatitic powders obtained were shown to contain small amounts of Na and K, which render them more similar in chemical composition to that of the bone mineral. Precipitated and dried powders were found to exhibit self-hardening cement properties when kneaded in a mortar with a sodium citrate- and sodium phosphate-containing starter solution. The same phosphate solution used in powder synthesis was found to be able to partially convert natural, white and translucent marble pieces of calcite (CaCO3) into calcium-deficient hydroxyapatite upon aging the samples in that solution for 3 days at 60 degrees C. Sample characterization was performed by using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, inductively-coupled plasma atomic emission spectroscopy, and simultaneous thermogravimetry and differential thermal analysis.

Salinity and hydrology of closed lakes

USGS Publications Warehouse

Langbein, Walter Basil

1961-01-01

Lakes without outlets, called closed lakes, are exclusively features of the arid and semiarid zones where annual evaporation exceeds rainfall. The number of closed lakes increases with aridity, so there are relatively few perennial closed lakes, but "dry" lakes that rarely contain water are numerous.Closed lakes fluctuate in level to a much greater degree than the open lakes of the humid zone, because variations in inflow can be compensated only by changes in surface area. Since the variability of inflow increases with aridity, it is possible to derive an approximate relationship for the coefficient of variation of lake area in terms of data on rates of evaporation, lake area, lake depth, and drainage area.The salinity of closed lakes is highly variable, ranging from less than 1 percent to over 25 percent by weight of salts. Some evidence suggests that the tonnage of salts in a lake solution is substantially less than the total input of salts into the lake over the period of existence of the closed lake. This evidence suggests further that the salts in a lake solution represent a kind of long-term balance between factors of gain and loss of salts from the solution.Possible mechanisms for the loss of salts dissolved in the lake include deposition in marginal bays, entrapment in sediments, and removal by wind. Transport of salt from the lake surface in wind spray is also a contributing, but seemingly not major, factor.The hypothesis of a long-term balance between input to and losses from the lake solution is checked by deriving a formula for the equilibrium concentration and comparing the results with the salinity data. The results indicate that the reported salinities seemingly can be explained in terms of their geometric properties and hydrologic environment.The time for accumulation of salts in the lake solution the ratio between mass of salts in the solution and the annual input may also be estimated from the geometric and hydrologic factors, in the absence of

pH Optrode Instrumentation

NASA Technical Reports Server (NTRS)

Tabacco, Mary Beth; Zhou, Quan

1995-01-01

pH-sensitive chromophoric reagents immobilized in porous optical fibers. Optoelectronic instrumentation system measures acidity or alkalinity of aqueous nutrient solution. Includes one or more optrodes, which are optical-fiber chemical sensors, in sense, analogous to electrodes but not subject to some of spurious effects distorting readings taken by pH electrodes. Concept of optrodes also described in "Ethylene-Vapor Optrodes" (KSC-11579). pH optrode sensor head, with lead-in and lead-out optical fibers, convenient for monitoring solutions located away from supporting electronic equipment.

Normal saline solution versus other viscous solutions for submucosal injection during endoscopic mucosal resection: a systematic review and meta-analysis.

PubMed

Yandrapu, Harathi; Desai, Madhav; Siddique, Sameer; Vennalganti, Prashanth; Vennalaganti, Sreekar; Parasa, Sravanthi; Rai, Tarun; Kanakadandi, Vijay; Bansal, Ajay; Titi, Mohammad; Repici, Alessandro; Bechtold, Matthew L; Sharma, Prateek; Choudhary, Abhishek

2017-04-01

EMR is being increasingly practiced for the removal of large colorectal polyps. A variety of solutions such as normal saline solution (NS) and other viscous and hypertonic solutions (VS) have been used as submucosal injections for EMR. A systematic review and meta-analysis is presented comparing the efficacy and adverse events of EMR performed using NS versus VS. Two independent reviewers conducted a search of all databases for human, randomized controlled trials that compared NS with VS for EMR of colorectal polyps. Data on complete en bloc resection, presence of residual lesions, and adverse events were extracted using a standardized protocol. Pooled odds ratio (OR) estimates along with 95% confidence intervals (CI) were calculated using fixed effect or random effects models. Five prospective, randomized controlled trials (504 patients) met the inclusion criteria. The mean polyp sizes were 20.84 mm with NS and 21.44 mm with VS. On pooled analysis, a significant increase in en bloc resection (OR, 1.91; 95% CI, 1.11-3.29; P = .02; I 2  = 0%) and decrease in residual lesions (OR, 0.54; 95% CI, 0.32-0.91; P = .02; I 2  = 0%) were noted in VS compared with NS. There was no significant difference in the rate of overall adverse events between the 2 groups. Use of VS during EMR leads to higher rates of en bloc resection and lower rates of residual lesions compared with NS, without any significant difference in adverse events. Endoscopists could consider using VS for EMR of large colorectal polyps and NS for smaller polyps because there is no significant difference in the outcomes with lesions <2 cm. Published by Elsevier Inc.

Biology, ecology, and biotechnological applications of anaerobic bacteria adapted to environmental stresses in temperature, pH, salinity, or substrates.

PubMed Central

Lowe, S E; Jain, M K; Zeikus, J G

1993-01-01

Anaerobic bacteria include diverse species that can grow at environmental extremes of temperature, pH, salinity, substrate toxicity, or available free energy. The first evolved archaebacterial and eubacterial species appear to have been anaerobes adapted to high temperatures. Thermoanaerobes and their stable enzymes have served as model systems for basic and applied studies of microbial cellulose and starch degradation, methanogenesis, ethanologenesis, acetogenesis, autotrophic CO2 fixation, saccharidases, hydrogenases, and alcohol dehydrogenases. Anaerobes, unlike aerobes, appear to have evolved more energy-conserving mechanisms for physiological adaptation to environmental stresses such as novel enzyme activities and stabilities and novel membrane lipid compositions and functions. Anaerobic syntrophs do not have similar aerobic bacterial counterparts. The metabolic end products of syntrophs are potent thermodynamic inhibitors of energy conservation mechanisms, and they require coordinated consumption by a second partner organism for species growth. Anaerobes adapted to environmental stresses and their enzymes have biotechnological applications in organic waste treatment systems and chemical and fuel production systems based on biomass-derived substrates or syngas. These kinds of anaerobes have only recently been examined by biologists, and considerably more study is required before they are fully appreciated by science and technology. Images PMID:8336675

Effects of the pH and Concentration on the Stability of Standard Solutions of Proteinogenic Amino Acid Mixtures.

PubMed

Kato, Megumi; Yamazaki, Taichi; Kato, Hisashi; Yamanaka, Noriko; Takatsu, Akiko; Ihara, Toshihide

2017-01-01

To prepare metrologically traceable amino acid mixed standard solutions, it is necessary to determine the stability of each amino acid present in the mixed solutions. In the present study, we prepared amino acid mixed solutions using certified reference standards of 17 proteinogenic amino acids, and examined the stability of each of these amino acids in 0.1 N HCl. We found that the concentration of glutamic acid decreased significantly during storage. LC/MS analysis indicated that the instability of glutamic acid was due to the partial degradation of glutamic acid to pyroglutamic acid in 0.1 N HCl. Using accelerated degradation tests, we investigated several solvent compositions to improve the stability of glutamic acid in amino acid mixed solution, and determined that the change of the pH by diluting the mixed solution improved the stability of glutamic acid.

Experimental study of the bending elasticity of charged lipid bilayers in aqueous solutions with pH5

NASA Astrophysics Data System (ADS)

Mitkova, D.; Stoyanova-Ivanova, A.; Ermakov, Yu A.; Vitkova, V.

2012-12-01

Exposure to high concentrations of contaminations due to air polluting gases, vapours and aerosols and possibly altering the normal pH in the body could lead to undesirable changes in the properties of biological cells. Here, we study experimentally the mechanical properties of synthetic phospholipid bilayers containing increasing molar fractions (up to 0.15) of charged lipid (synthetic phosphatidylserine) in aqueous solutions with controlled ionic strength and at pH 5, which is slightly lower than the physiological values of pH. Our observations in phase contrast and fluorescence testified to the coexistence of two phases in membranes for temperatures below 29°C. Micro-sized inhomogeneities in vesicle membranes were systematically observed at temperatures lower than 29°C and for molar fractions of phosphatidylserine in the bilayer higher than 0.1. For the quantitative determination of the membrane bending rigidity, we applied thermal fluctuation analysis of the shape of quasispherical lipid vesicles. As far as the liquid-crystalline state of the bilayer is a necessary condition for the application of the experimental method, only vesicles satisfying this requirement were processed for determination of their membrane bending rigidity. The value obtained for the bending modulus of bilayers with 0.15 molar content of charged lipid is about two times higher than the bending modulus of uncharged membranes in the same bathing solution. These findings are in qualitative agreement with our previous results for the bending rigidity of charged bilayers, measured by vesicle micromanipulation.

Effect of pH on the Electrophoretic Mobility of Spores of Bacillus anthracis and Its Surrogates in Aqueous Solutions

EPA Science Inventory

Electrophoretic mobility (EPM) of endospores of Bacillus anthracis and surrogates were measured in aqueous solution across a broad pH range and several ionic strengths. EPM values trended around phylogenetic clustering based on the 16S rRNA gene. Measurements reported here prov...

Online PH measurement technique in seawater desalination

NASA Astrophysics Data System (ADS)

Wang, Haibo; Wu, Kaihua; Hu, Shaopeng

2009-11-01

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

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.

Diffusion of Eu(III) in compacted bentonite-effect of pH, solution concentration and humic acid.

PubMed

Wang, Xiangke; Chen, Yixue; Wu, Yican

2004-06-01

The effect of pH, Eu(III) solution concentration and humic acid on the diffusion of Eu(III) in compacted bentonite (rho(b) = 1000 +/- 30 kg/m(3)) was studied with "in-diffusion" method at an ionic strength of 0.1M NaClO(4). The results (K(d) values from the first slice and theoretical calculation, apparent and effective diffusion coefficients) derived from the new capillary method are in good agreement with the literature data under similar conditions, and fit the Fick's second law very well. The results suggest that the diffusion of Eu(III) is dependent on pH values and independent on solution concentration in our experimental conditions. Humic acid forms precipitation/complexation with Eu(III) at the surface of compacted bentonite and thus deduces the diffusion/transport of Eu(III) in compacted bentonite. The K(d) values in compacted bentonite are in most cases lower than those in powdered bentonite obtained from batch experiments. The difference between the K(d) values from powdered and compacted bentonite is a strong function of the bulk density of the bentonite. The results suggest that the content of interlaminary space plays a very important role to the diffusion, sorption and migration of Eu(III) in compacted bentonite.

The pH of water from various sources: an overview for recommendation for patients with atopic dermatitis.

PubMed

Kulthanan, Kanokvalai; Nuchkull, Piyavadee; Varothai, Supenya

2013-07-01

Patients with atopic dermatitis (AD) have increased susceptibility to irritants. Some patients have questions about types of water for bathing or skin cleansing. We studied the pH of water from various sources to give an overview for physicians to recommend patients with AD. Water from various sources was collected for measurement of the pH using a pH meter and pH-indicator strips. Bottled drinking still water had pH between 6.9 and 7.5 while the sparkling type had pH between 4.9 and 5.5. Water derived from home water filters had an approximate pH of 7.5 as same as tap water. Swimming pool water had had pH between 7.2 and 7.5 while seawater had a pH of 8. Normal saline and distilled water had pH of 5.4 and 5.7, respectively. Facial mineral water had pH between 7.5 and 8, while facial makeup removing water had an acidic pH. Normal saline, distilled water, bottled sparkling water and facial makeup removing water had similar pH to that of normal skin of normal people. However, other factors including benefits of mineral substances in the water in terms of bacteriostatic and anti-inflammation should be considered in the selection of cleansing water.

The pH of water from various sources: an overview for recommendation for patients with atopic dermatitis

PubMed Central

Kulthanan, Kanokvalai; Varothai, Supenya

2013-01-01

Background Patients with atopic dermatitis (AD) have increased susceptibility to irritants. Some patients have questions about types of water for bathing or skin cleansing. Objective We studied the pH of water from various sources to give an overview for physicians to recommend patients with AD. Methods Water from various sources was collected for measurement of the pH using a pH meter and pH-indicator strips. Results Bottled drinking still water had pH between 6.9 and 7.5 while the sparkling type had pH between 4.9 and 5.5. Water derived from home water filters had an approximate pH of 7.5 as same as tap water. Swimming pool water had had pH between 7.2 and 7.5 while seawater had a pH of 8. Normal saline and distilled water had pH of 5.4 and 5.7, respectively. Facial mineral water had pH between 7.5 and 8, while facial makeup removing water had an acidic pH. Conclusion Normal saline, distilled water, bottled sparkling water and facial makeup removing water had similar pH to that of normal skin of normal people. However, other factors including benefits of mineral substances in the water in terms of bacteriostatic and anti-inflammation should be considered in the selection of cleansing water. PMID:23956962

The Semen pH Affects Sperm Motility and Capacitation.

PubMed

Zhou, Ji; Chen, Li; Li, Jie; Li, Hongjun; Hong, Zhiwei; Xie, Min; Chen, Shengrong; Yao, Bing

2015-01-01

As the chemical environment of semen can have a profound effect on sperm quality, we examined the effect of pH on the motility, viability and capacitation of human sperm. The sperm in this study was collected from healthy males to avoid interference from other factors. The spermatozoa cultured in sperm nutrition solution at pH 5.2, 6.2, 7.2 and 8.2 were analyzed for sperm total motility, progressive motility (PR), hypo-osmotic swelling (HOS) rate, and sperm penetration. Our results showed that these parameters were similar in pH 7.2 and 8.2 sperm nutrition solutions, but decreased in pH 5.2 and 6.2 solutions. The HOS rate exhibited positive correlation with the sperm total motility and PR. In addition, the sperm Na(+)/K(+)-ATPase activity at different pHs was measured, and the enzyme activity was significantly lower in pH 5.2 and 6.2 media, comparing with that in pH 8.2 and pH 7.2 solutions. Using flow cytometry (FCM) and laser confocal scanning microscopy (LCSM) analysis, the intracellular Ca2(+ )concentrations of sperm cultured in sperm capacitation solution at pH 5.2, 6.2, 7.2 and 8.2 were determined. Compared with that at pH 7.2, the mean fluorescence intensity of sperm in pH 5.2 and 6.2 media decreased significantly, while that of pH 8.2 group showed no difference. Our results suggested that the declined Na(+)/K(+)-ATPase activity at acidic pHs result in decreased sperm movement and capacitation, which could be one of the mechanisms of male infertility.

Enzymatic characterization of peptidic materials isolated from aqueous solutions of ammonium cyanide (pH 9) and hydrocyanic acid (pH 6) exposed to ionizing radiation.

PubMed

Niketic, V; Draganić, Z; Nesković, S; Draganić, I

1982-01-01

The enzymatic digestion of some radiolytically produced peptidic materials was examined. The substrates were compounds isolated from 0.1 molar solutions of NH4CN (pH 9) and HCN (pH 6), after their exposure to gamma rays from a 60Co source (15-20 Mrad doses). Commercial proteolytic enzymes pronase and aminopeptidase M were used. The examined materials were of composite nature and proteolytic action was systematically observed after their subsequent purification. In some fractions the effect was found to be positive with up to 30% of peptide bonds cleaved with respect to the amino acid content. These findings support our previous conclusions on the free radical induced formation of peptidic backbones without the intervention of amino acids. Some side effects were also noted which might be of interest in observations on enzymatic cleavage of other composite peptidic materials of abiotic origin.

Time course of the acute response of the North Pacific spiny dogfish shark (Squalus suckleyi) to low salinity.

PubMed

Guffey, Samuel C; Goss, Greg G

2014-05-01

Dogfish are considered stenohaline sharks but are known to briefly enter estuaries. The acute response of North Pacific spiny dogfish (Squalus suckleyi) to lowered salinity was tested by exposing sharks to 21‰ salinity for 48 h. Temporal trends in blood pH, plasma osmolality, CO2, HCO3(-), Na(+), Cl(-), K(+), and urea concentrations, and in the rates of urea efflux and O2 consumption, were quantified. The rate of O2 consumption exhibited cyclic variation and was significantly depressed by lowered salinity. After 9 h, plasma [Cl(-)] stabilized at 9% below initial levels, while plasma [Na(+)] decreased by more than 20% within the first 12 h. Plasma [urea] dropped by 15% between 4 and 6 h, and continued to decrease. The rate of urea efflux increased over time, peaking after 36 h at 72% above the initial rate. Free-swimming sharks subjected to the same salinity challenge survived over 96 h and differed from cannulated sharks with respect to patterns of Na(+) and urea homeostasis. This high-resolution study reveals that dogfish exposed to 21‰ salinity can maintain homeostasis of Cl(-) and pH, but Na(+) and urea continue to be lost, likely accounting for the inability of the dogfish to fully acclimate to reduced salinity. Copyright © 2014 Elsevier Inc. All rights reserved.

Corrosion behavior of pristine and added MgB2 in Phosphate Buffered Saline Solution

NASA Astrophysics Data System (ADS)

Batalu, D.; Bojin, D.; Ghiban, B.; Aldica, G.; Badica, P.

2012-09-01

We have obtained by Spark Plasma Sintering (SPS), dense samples of MgB2 added with Ho2O3. Starting composition was (MgB2)0.975(HoO1.5)0.025 and we used addition powders with an average particle size below and above 100 nm. For Mg, pristine and added MgB2 samples we measured potentiodynamic polarization curves in Phosphate Buffered Saline (PBS) solution media at room temperature. MgB2 based composites show corrosion/ degradation effects. This behavior is in principle similar to Mg based alloys in the same media. Our work suggests that the different morphologies and phase compositions of the SPS-ed samples influence the interaction with corrosion medium; hence additions can play an important role in controlling the corrosion rate. Pristine MgB2 show a significant improvement of the corrosion resistance, if compared with Mg. The best corrosion resistance is obtained for pristine MgB2, followed by MgB2 with nano-Ho2O3 and μ-Ho2O3 additions.

On the Balancing of the SMOS Ocean Salinity Retrieval Cost Function

NASA Astrophysics Data System (ADS)

Sabia, R.; Camps, A.; Portabella, M.; Talone, M.; Ballabrera, J.; Gourrion, J.; Gabarró, C.; Aretxabaleta, A. L.; Font, J.

2009-04-01

The Soil Moisture and Ocean Salinity (SMOS) mission will be launched in mid 2009 to provide synoptic sea surface salinity (SSS) measurements with good temporal resolution [1]. To obtain a proper estimation of the SSS fields derived from the multi-angular brightness temperatures (TB) measured by the Microwave Interferometric Radiometer by Aperture Synthesis (MIRAS) sensor, a comprehensive inversion procedure has been defined [2]. Nevertheless, several salinity retrieval issues remain critical, namely: 1) Scene-dependent bias in the simulated TBs, 2) L-band forward geophysical model function definition, 3) Auxiliary data uncertainties, 4) Constraints in the cost function (inversion), especially in salinity term, and 5) Adequate spatio-temporal averaging. These issues will have to be properly addressed in order to meet the proposed accuracy requirement of the mission: a demanding 0.1 psu (practical salinity units) after averaging in a 30-day and 2°x2° spatio-temporal boxes. The salinity retrieval cost function minimizes the difference between the multi-angular measured SMOS TBs (yet simulated, so far) and the modeled TBs, weighted by the corresponding radiometric noise of the measurements. Furthermore, due to the fact that the minimization problem is both non-linear and ill-posed, background reference terms are needed to nudge the solution and ensuring convergence at the same time [3]. Constraining terms in SSS, sea surface temperature (SST) and wind speed are considered with their respective uncertainties. Moreover, whether SSS constraints have to be included or not as part of the retrieval procedure is still a matter of debate. On one hand, neglecting background reference information on SSS might prevent from retrieving salinity with the prescribed accuracy or at least within reasonable error. Conversely, including constraints in SSS, relying for instance on the climatology, may force the retrieved value to be too close to the reference prior values, thus

The motility and motion duration of jatimbulan tilapia (Oreochromis niloticus) spermatozoa in different salinity

NASA Astrophysics Data System (ADS)

Triastuti, J.; Kintani, D.; Luqman, E. M.; Pujiastuti, D. Y.

2018-04-01

Tilapia hatchery is still conducted in freshwater and seeds are death simultaneousy when cultivated in high salinity due to the acclimatization process. An alternative method to implement hatchery at high salinity is required. This study aims to determine the salinity of activation medium that provides the best Jatimbulan Tilapia sperm motility and motion duration at high salinity. The study applies completely randomized design (CRD), which consists of 5 treatments (0 ppt, 4 ppt, 9 ppt, 14 ppt and 19 ppt) and 4 repetitions. The parameters consists of sperm motility, motion duration, fresh sperm data (volume, color, odor, pH, consistency, and the concentration of sperm) and sperm abnormalities. The results exhibited that salinity significantly (p < 0.05). Influeneed the sperm motility and motion duration. Motility reaches its best at 0 ppt and 4 ppt (93.4 % and 87.8 %). For motion duration, best condition was in 0 ppt and 4 ppt treatments, totaling 2128 seconds and 1961.5 seconds. Meanwhile, sperm did not move when treated in waters with 9 ppt, 14 ppt and 19 ppt salinities.

16 CFR 1500.134 - Policy on first aid labeling for saline emesis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Policy on first aid labeling for saline... REGULATIONS § 1500.134 Policy on first aid labeling for saline emesis. (a) This section states the Consumer Product Safety Commission's policy concerning first aid instructions for the use of a salt solution to...

Effects of solution pH and electrical parameters on hydroxyapatite coatings deposited by a plasma-assisted electrophoresis technique.

PubMed

Nie, X; Leyland, A; Matthews, A; Jiang, J C; Meletis, E I

2001-12-15

Hydroxyapatite (HA) coatings can be deposited using a hybrid process of plasma electrolysis and electrophoresis, called plasma-assisted electrophoretic deposition (PEPD). HA aqueous suspensions with various pH values were prepared using a modified ultrasonic cleaning bath as an agitator/stirrer. Both DC and unbalanced AC power supplies were used to bias the titanium alloy substrate materials employed in this work. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to observe and analyze coating morphology and microstructure. It was shown that the morphology and composition of the calcium phosphate coatings were significantly influenced by solution pH values; the level of "pure" HA in the coatings' composition corresponded to both solution pH and the type of power supply employed. Loss of hydroxyl radials (i.e., dehydroxylation), which degrades the performance of the hydroxyapatite coating in terms of long-term chemical and mechanical stability, can be virtually eliminated by a combination of high pH and unbalanced AC plasma power. In addition, the underlying TiO2 coatings used to support the HA layer (preproduced by plasma electrolysis process) have a nanoscaled (10-20 nm) polycrystalline structure. TEM studies also revealed a dense, continuous amorphous titania layer (10 nm in thickness) at the interface between the Ti alloy substrate and the TiO2 layer, which may play a role in improving the corrosion resistance of the substrate. Such a nanophase TiO2 layer (if used as a coating alone) may also provide a further improvement in osteoinductive properties, compared to a conventional TiO2 coating on the Ti alloy substrate. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 57: 612-618, 2001

Agglomeration of Luminescent Porous Silicon Nanoparticles in Colloidal Solutions

NASA Astrophysics Data System (ADS)

Herynková, Kateřina; Šlechta, Miroslav; Šimáková, Petra; Fučíková, Anna; Cibulka, Ondřej

2016-08-01

We have prepared colloidal solutions of clusters composed from porous silicon nanoparticles in methanol, water and phosphate-buffered saline (PBS). Even if the size of the nanoclusters is between 60 and 500 nm, due to their highly porous "cauliflower"-like structure, the porous silicon nanoparticles are composed of interconnected nanocrystals having around 2.5 nm in size and showing strong visible luminescence in the orange-red spectral region (centred at 600-700 nm). Hydrophilic behaviour and good solubility of the nanoclusters in water and water-based solutions were obtained by adding hydrogen peroxide into the etching solution during preparation and 16 min long after-bath in hydrogen peroxide. By simple filtration of the solutions with syringe filters, we have extracted smaller nanoclusters with sizes of approx. 60-70 nm; however, these nanoclusters in water and PBS solution (pH neutral) are prone to agglomeration, as was confirmed by zeta potential measurements. When the samples were left at ambient conditions for several weeks, the typical nanocluster size increased to approx. 330-400 nm and then remained stable. However, both freshly filtered and aged samples (with agglomerated porous silicon nanoparticles) of porous silicon in water and PBS solutions can be further used for biological studies or as luminescent markers in living cells.

Effects of Hydrogen-Rich Saline on Hepatectomy-Induced Postoperative Cognitive Dysfunction in Old Mice.

PubMed

Tian, Yue; Guo, Shanbin; Zhang, Yan; Xu, Ying; Zhao, Ping; Zhao, Xiaochun

2017-05-01

This study aims to investigate the protective effects and underlying mechanisms of hydrogen-rich saline on the cognitive functions of elder mice with partial hepatectomy-induced postoperative cognitive dysfunction (POCD). Ninety-six old male Kunming mice were randomly divided into 4 groups (n = 24 each): control group (group C), hydrogen-rich saline group (group H), POCD group (group P), and POCD + hydrogen-rich saline group (group PH). Cognitive function was subsequently assessed using Morris water-maze (MWM) test. TNF-α and IL-1β levels were measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, along with NF-κB activity determined by ELISA. The morphology of hippocampal tissues were further observed by HE staining. Learning and memory abilities of mice were significantly impaired at day 10 and day 14 post-surgery, as partial hepatectomy significantly prolonged the escape latency, decreased time at the original platform quadrant and frequency of crossing in group P when compared to group C (p < 0.05). The surgery also increased the contents of TNF-α, IL-1β, and NF-κB activity at all time points after surgery (p < 0.05). The introduction of hydrogen-rich saline (group PH) partially rescued spatial memory and learning as it shortened escape latency and increased time and crossing frequency of original platform compared to group P (p < 0.05). Moreover, such treatment also decreased TNF-α and IL-1β levels and NF-κB activity (p < 0.05). In addition, cell necrosis in the hippocampus induced by hepatectomy was also rescued by hydrogen-rich saline. Hydrogen-rich saline can alleviate POCD via inhibiting NF-κB activity in the hippocampus and reducing inflammatory response.

Making pH Tangible.

ERIC Educational Resources Information Center

McIntosh, Elizabeth; Moss, Robert

1995-01-01

Presents a laboratory exercise in which students test the pH of different substances, study the effect of a buffer on acidic solutions by comparing the behavior of buffered and unbuffered solutions upon the addition of acid, and compare common over-the-counter antacid remedies. (MKR)

Deciphering the protective role of spermidine against saline-alkaline stress at physiological and proteomic levels in tomato.

PubMed

Zhang, Yi; Zhang, Hao; Zou, Zhi-Rong; Liu, Yi; Hu, Xiao-Hui

2015-02-01

In this research, the protective effect of spermidine (Spd) in mitigating saline-alkaline stress in tomato (Solanum lycopersicum L.) at physiological and proteomic levels were examined. The results showed that saline-alkaline stress induced accumulation of H2O2 and O2(-*), and increased the activities of antioxidase (SOD, CAT, and POD). Spermidine efficiently alleviated the inhibitory role of saline-alkaline on plant growth and inhibited saline-alkaline stress-induced H2O2 and O2(-*) accumulation. Proteomics investigations of the leaves of tomato seedlings, responding to a 75 mM saline-alkaline solution and 0.25 mM Spd, were performed. Maps of the proteome of leaf extracts were obtained by two-dimensional gel electrophoresis. An average of 49, 47 and 34 spots, which appeared repeatedly and that significantly altered the relative amounts of polypeptides by more than twofold, were detected for seedlings treated with saline-alkaline solution (S) compared to normal solution (CK), saline-alkaline plus spermidine (MS) compared to CK, or S versus MS, respectively. Thirty-nine of these proteins were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and were classified into five functional categories, including energy and metabolism, signal transduction, amino acid metabolism, protein metabolism, and stress-defense response. Proteomics analysis coupled with bioinformatics indicated that Spd treatment helps tomato seedlings combat saline-alkaline stress by modulating the defense mechanism of plants and activating cellular detoxification, which protect plants from oxidative damage induced by saline-alkaline stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

Measurements of spectral responses for developing fiber-optic pH sensor

NASA Astrophysics Data System (ADS)

Yoo, Wook Jae; Heo, Ji Yeon; Jang, Kyoung Won; Seo, Jeong Ki; Moon, Jin Soo; Park, Jang-Yeon; Park, Byung Gi; Cho, Seunghyun; Lee, Bongsoo

2011-01-01

In this study, we have fabricated a fiber-optic pH sensor, which is composed of a light source, a pH-sensing probe, plastic optical fibers and a spectrometer, for determining the degree of infection by Helicobacter pylori in the stomach. As pH indicators, phenol red and m-cresol purple are used, and pH liquid solutions are prepared by mixing phenol red or m-cresol purple solutions and various kinds of pH buffer solutions. The light emitted by a light source is guided by plastic optical fibers to the pH liquid solution, and the optical characteristic of a reflected light is changed according to the color variations of the pH indicator in the pH-sensing probe. Therefore, we have measured the intensities and wavelength shifts of the reflected lights, which change according to the color variations of indicators at different pH values, by using a spectrometer for spectral analysis. Also, the relationships between the pH values of liquid solutions and the optical properties of the modulated lights are obtained on the basis of the changes of the colors of indicators.

Responses of spinach to salinity and nutrient deficiency in growth, physiology and nutritional value

USDA-ARS?s Scientific Manuscript database

Salinity and nutrient depleted soil are major constraints to crop production, especially for vegetable crops. The effects of salinity and nutrient deficiency on spinach were evaluated in sand cultures under greenhouse conditions. Plants were watered every day with Hoagland nutrition solution, depriv...

Equiosmolar Solutions of Hypertonic Saline and Mannitol Do Not Impair Blood Coagulation During Elective Intracranial Surgery.

PubMed

Hernández-Palazón, Joaquín; Fuentes-García, Diego; Doménech-Asensi, Paloma; Piqueras-Pérez, Claudio; Falcón-Araña, Luis; Burguillos-López, Sebastián

2017-01-01

The authors investigated the effect of equiosmolar, equivolemic solutions of 3% hypertonic saline (HS) and 20% mannitol on blood coagulation assessed by rotational thromboelastometry (ROTEM) and standard coagulation tests during elective craniotomy. In a prospective, randomized, double-blind trial, 40 patients undergoing elective craniotomy were randomized to receive 5 mL/kg of either 20% mannitol or 3% HS for intraoperative brain relaxation. Fibrinogen, activated partial thromboplastin time, prothrombin time, hemoglobin, hematocrit, and platelet count were simultaneously measured intraoperatively with ROTEM for EXTEM, INTEM, and FIBTEM analysis. ROTEM parameters were: clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), and α-angle. No significant differences between groups were found in ROTEM variables CT, CFT, MCF, α-angle (EXTEM and INTEM), and MCF (FIBTEM) nor standard coagulation tests. ROTEM parameters did not show changes after administration of hyperosmolar solutions relating to basal values, except for an increase of CFT EXTEM (118±28 vs. 128±26 s) and decrease of CT INTEM (160±18 vs. 148±15 s) with values within normal range. Significant decreases from baseline levels were observed for hematocrit (-7%), platelet count (-10%), and fibrinogen (-13%) after HS infusion, and hematocrit (-9%), platelet count (-13%), and fibrinogen (-9%) after mannitol infusion, but remaining normal. The use of 5 mL/kg of equiosmolar solutions of 3% HS and 20% mannitol applied to reach a brain relaxation during elective craniotomy does not induce coagulation impairment as evidenced by ROTEM and standard coagulation tests.

Ultrastructure in frozen/etched saline solutions: on the internal cleansing of ice.

PubMed

Menger, Fredric M; Galloway, Ashley L; Chlebowski, Mary E; Apkarian, Robert P

2004-05-19

Seawater, with its 3.5% salt content, freezes into hexagonal ice (Ih) that encloses concentrated brine within its matrix. When unsubmerged sea ice reaches a certain height and temperature, the brine drains downward through narrow channels. This mechanism was now modeled by frozen 2-3.5% saline as investigated by cryo-etch high-resolution secondary electron microscopy. Thus, saline was either plunge-frozen in liquid ethane at -183 degrees C or else high-pressure frozen to -105 degrees C in 5-6 ms. Ice from a freshly exposed surface was then subjected to a high-vacuum sublimation ("etching"), a procedure that removes pure bulk ice in preference to ice from frozen hydrated salt. After chromium-coating the etched surface with a 2-nm film, the sample was examined by cryo-HRSEM. Granular icy "fences" were seen surrounding empty areas where amorphous ice had originally resided. Since the fences, about 1-2 mum high, survived the etching, it is likely that they consist of frozen brine. The presence of such fences suggests that, during freezing, saline can purge itself of salt with remarkable speed (5-6 ms). Alternatively, channels (perhaps routed around submicroscopic crystallites of cubic ice (Ic) embedded in the amorphous ice at -105 degrees C) can guide the migration of salt to the periphery of ice patches. Macromolecules fail to form fences because they diffuse too slowly or because they are too large to pass through the channels.

Mechanisms Controlling Variability of Lake Salinity in Dune Environments in a Semi-arid Climate: The Nebraska Sand Hills (Invited)

NASA Astrophysics Data System (ADS)

Zlotnik, V. A.; Ong, J. T.; Swinehart, J. B.; Fritz, S. C.; Lenters, J. D.; Schmieder, J. U.; Lane, J. W.; Halihan, T.

2010-12-01

Shallow endorheic saline lakes are common in semi-arid environments in North America, Africa, Asia, and Australia. These lakes receive minimal surface runoff and are supported by groundwater seepage. A combination of hydrologic and geologic factors (regional groundwater flow, evaporation, precipitation, lake size, groundwater recharge, and geologic setting) may preclude seepage out of these lakes, even in the presence of ambient regional flow. Solutes from groundwater are captured by these lakes and become enriched over time by evaporation. The importance of understanding lake dynamics in these arid and semi-arid systems is increasing with societal concerns, including water availability and quality, the use of aquatic ecosystems by waterfowl and other biota, and dangers of dust emissions associated with lake desiccation. We consider the salinity of shallow lakes as a useful indicator of hydroclimatic factors operating at centennial and millennial scales. The Nebraska Sand Hills cover 58 000 km2 of the central Great Plains and are the largest dunefield in the Western Hemisphere. The grass-stabilized dunes attain heights up to 130 m and have been modified by soil development and erosion. In an area <7000 km2, there are ~400 lakes with surface areas >4 ha and depths <1 m. Annual lake evaporation exceeds precipitation by 600 mm, according to some estimates. The salinity of natural lakes in the Nebraska Sand Hills ranges from fresh (~0.3 g L-1) to hypersaline (>100 g L-1), with pH values as high as ~10. We assess the mechanisms that control lake salinity in a group of lakes with different subsurface flow regimes. Our methods combine aquifer coring, electromagnetic and electrical resistivity tomography geophysics, hydraulic testing, lakebed dating using 14C and optically stimulated luminescence, energy and water balance analysis, and salt crust and dust collection. Our theory and results show that terrain and water-table topography, lithology, and climate control the

[Massive transfusion of washed red blood cells: acid-base and electrolyth changes for different wash solutions].

PubMed

Sümpelmann, R; Schürholz, T; Marx, G; Ahrenshop, O; Zander, R

2003-09-01

The composition of normal saline (NaCl), the standard wash solution for cell saver autotransfusion, is considerably different from physiologic plasma values in small infants. Therefore, we investigated acid-base and electrolyte changes during massive cell saver autotransfusion with different wash solutions in young pigs. After approval by the animal protection authorities 15 young pigs (weight 10.6 +/- 1.1 kg, blood volume 848 +/- 88 ml, mean+/-SD) underwent 15 cycles of cell saver autotransfusion (Haemolite 2plus, Haemonetics). For each cycle, 100 ml arterial blood was withdrawn, washed with NaCl, physiologic multielectrolyte solution (PME, V Infusionslösung 296 mval Elektrolyte, Baxter) or physiologic erythrocyte protection solution (PEP, 3.2 % gelatine, pH 7.40, cHCO3 24 mmol/l), and then retransfused. Analyses of acid-base, electrolyte, and hematologic parameters were performed for systemic and washed blood samples. For NaCl there was a progressive decrease in systemic pH, HCO3 and base excess (BE) and an increase in chloride values (Cl) (p < 0.05). Use of PME slightly decreased pH (n. s.), whereas HCO3, BE and Cl remained stable. PEP slightly increased pH, HCO3 and BE, and decreased Cl (n. s.). Free hemoglobin increased in NaCl and PME (p < 0.05) and was below baseline in PEP (n. s.). Lactic acid course was comparable in all groups. The use of NaCl as wash solution for massive autotransfusion resulted in metabolic acidosis caused by dilution of HCO3 and increased Cl values. Fewer systemic acid-base and electrolyte changes were observed, when blood was washed with PME or PEP. The decreased hemoglobin release with PEP is possibly due to a gelatine specific electrostatic surface coating of erythrocyte membranes. For massive transfusion of washed red blood cells, physiologic multielectrolyte solution and physiologic erythrocyte protection solution should be preferred to NaCl, especially for small infants.

Alkalinity-salinity relationship in the Chesapeake Bay

NASA Astrophysics Data System (ADS)

Cintrón Del Valle, S. M.; Najjar, R.; Herrmann, M.; Goldberger, S.; Stets, E.

2016-12-01

Estuaries are a significant source of atmospheric CO2, a major greenhouse gas. However, it is not known whether the Chesapeake Bay, the largest estuary in the United States, is a source or sink of CO2. Extensive pH measurements in the Bay offer the possibility of estimating the air-water CO2 flux if robust relationships between alkalinity, the acid neutralizing capacity of a water body, and salinity can be established. Here we conduct a comprehensive analysis of the alkalinity-salinity relationship in the Chesapeake Bay based on more than 18,000 alkalinity measurements made between 1985 and 2015. It was found that seven segments of the Bay could be grouped into three different linear functions, suggesting that alkalinity is conserved in the Bay and has properties that change depending on the freshwater endmember (the riverine source). The highest freshwater endmember was 1.21 mol m-3 for the Potomac River, the lowest one was 0.41 mol m-3 for the York and Rappahannock Rivers, and an intermediate freshwater endmember was 0.79 mol m-3 for the remaining four segments. For some segments, most notably the Potomac River, the scatter of the data increases with decreasing salinity, which is due, in part, to seasonal and interannual variations in the freshwater endmember.

[Spatial heterogeneity of soil salinization and its influencing factors in the typical region of the Mu Us Desert-Loess Plateau transitional zone, Northwest China].

PubMed

Zhao, Xuan; Hao, Qi Li; Sun, Ying Ying

2017-06-18

Studies on the spatial heterogeneity of saline soil in the Mu Us Desert-Loess Plateau transition zone are meaningful for understanding the mechanisms of land desertification. Taking the Mu Us Desert-Loess Plateau transition zone as the study subject, its spatial heterogeneity of pH, electrical conductivity (EC) and total salt content were analyzed by using on-site sampling followed with indoor analysis, classical statistical and geostatistical analysis. The results indicated that: 1) The average values of pH, EC and total salt content were 8.44, 5.13 mS·cm -1 and 21.66 g·kg -1 , respectively, and the coefficient of variation ranged from 6.9% to 73.3%. The pH was weakly variable, while EC and total salt content were moderately variable. 2) Results of semivariogram analysis showed that the most fitting model for spatial variability of all three indexes was spherical model. The C 0 /(C 0 +C) ratios of three indexes ranged from 8.6% to 14.3%, which suggested the spatial variability of all indexes had a strong spatial autocorrelation, and the structural factors played a more important role. The variation range decreased in order of pH pH, EC and total salt content distributed in a striped pattern with good continuity. The pH value increased with increasing terrain slope, while EC and total salt content decreased. 3) In terms of vertical distribution, the salt aggregated on surface in the area with severe salinization. In the area with light salinization, the vertical distribution of salinity was firstly decreased and then increased. In general, the heterogeneity of soil salinization in the Mu Us Desert-Loess Plateau transition zone was influenced by climate, landscape, plant distribution, especially affected by geological conditions, topography and hydrogeological conditions. This study provided a theoretical basis for future land engineering and ecosystem restoration programs.

Photocatalytic degradation of humic acid in saline waters. Part 1. Artificial seawater: influence of TiO2, temperature, pH, and air-flow.

PubMed

Al-Rasheed, Radwan; Cardin, David J

2003-06-01

We report the first systematic study on the photocatalytic oxidation of humic acid (HA) in artificial seawater (ASW). TiO(2) (Degussa P25) dispersions were used as the catalyst with irradiation from a medium-pressure mercury lamp. The optimum quantity of catalyst was found to be between 2 and 2.5 gl(-1); while the decomposition was fastest at low pH values (pH 4.5 in the range examined), and the optimum air-flow, using an immersion well reactor with a capacity of 400 ml, was 850 ml min(-1). Reactivity increased with air-flow up to this figure, above which foaming prevented operation of the reactor. Using pure oxygen, an optimal flow rate was observed at 300 ml min(-1), above which reactivity remains essentially constant. Following treatment for 1 h, low-salinity water (2700 mg l(-1)) was completely mineralised, whereas ASW (46000 mg l(-1)) had traces of HA remaining. These effects are interpreted and kinetic data presented. To avoid problems of precipitation due to change of ionic strength humic substances were prepared directly in ASW, and the effects of ASW on catalyst suspension and precipitation have been taken into account. The Langmuir-Hinshelwood kinetic model has been shown to be followed only approximately for the catalytic oxidation of HA in ASW. The activation energy for the reaction derived from an Arrhenius treatment was 17 (+/-0.6) kJ mol(-1).

Empirical algorithms to estimate water column pH in the Southern Ocean

NASA Astrophysics Data System (ADS)

Williams, N. L.; Juranek, L. W.; Johnson, K. S.; Feely, R. A.; Riser, S. C.; Talley, L. D.; Russell, J. L.; Sarmiento, J. L.; Wanninkhof, R.

2016-04-01

Empirical algorithms are developed using high-quality GO-SHIP hydrographic measurements of commonly measured parameters (temperature, salinity, pressure, nitrate, and oxygen) that estimate pH in the Pacific sector of the Southern Ocean. The coefficients of determination, R2, are 0.98 for pH from nitrate (pHN) and 0.97 for pH from oxygen (pHOx) with RMS errors of 0.010 and 0.008, respectively. These algorithms are applied to Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) biogeochemical profiling floats, which include novel sensors (pH, nitrate, oxygen, fluorescence, and backscatter). These algorithms are used to estimate pH on floats with no pH sensors and to validate and adjust pH sensor data from floats with pH sensors. The adjusted float data provide, for the first time, seasonal cycles in surface pH on weekly resolution that range from 0.05 to 0.08 on weekly resolution for the Pacific sector of the Southern Ocean.

Comparison of 7.2% hypertonic saline - 6% hydroxyethyl starch solution and 6% hydroxyethyl starch solution after the induction of anesthesia in patients undergoing elective neurosurgical procedures.

PubMed

Shao, Liujiazi; Wang, Baoguo; Wang, Shuangyan; Mu, Feng; Gu, Ke

2013-01-01

The ideal solution for fluid management during neurosurgical procedures remains controversial. The aim of this study was to compare the effects of a 7.2% hypertonic saline - 6% hydroxyethyl starch (HS-HES) solution and a 6% hydroxyethyl starch (HES) solution on clinical, hemodynamic and laboratory variables during elective neurosurgical procedures. Forty patients scheduled for elective neurosurgical procedures were randomly assigned to the HS-HES group orthe HES group. Afterthe induction of anesthesia, patients in the HS-HES group received 250 mL of HS-HES (500 mL/h), whereas the patients in the HES group received 1,000 mL of HES (1000 mL/h). The monitored variables included clinical, hemodynamic and laboratory parameters. Chictr.org: ChiCTR-TRC-12002357 The patients who received the HS-HES solution had a significant decrease in the intraoperative total fluid input (p<0.01), the volume of Ringer's solution required (p<0.05), the fluid balance (p<0.01) and their dural tension scores (p<0.05). The total urine output, blood loss, bleeding severity scores, operation duration and hemodynamic variables were similar in both groups (p>0.05). Moreover, compared with the HES group, the HS-HES group had significantly higher plasma concentrations of sodium and chloride, increasing the osmolality (p<0.01). Our results suggest that HS-HES reduced the volume of intraoperative fluid required to maintain the patients undergoing surgery and led to a decrease in the intraoperative fluid balance. Moreover, HS-HES improved the dural tension scores and provided satisfactory brain relaxation. Our results indicate that HS-HES may represent a new avenue for volume therapy during elective neurosurgical procedures.

Characterization of soil salinization in typical estuarine area of the Jiaozhou Bay, China

NASA Astrophysics Data System (ADS)

Li, Qifei; Xi, Min; Wang, Qinggai; Kong, Fanlong; Li, Yue

2018-02-01

In this study, the characteristics of soil salinization and the effects of main land use/land cover and other factors in typical estuarine area of the Jiaozhou Bay are investigated. Soil samples were collected in the parallel coastal zone, vertical coastal zone and longitudinal profile depth in the area to determine the soil salt content. The correlation analysis and principal component analysis are used to address the general characteristics of soil salinization in the study area. In the horizontal direction, there are moderate salinization, severe salinization and saline soil state. The farther from the sea (within 1.1 km), the lower the soil salinization degree. In the direction of longitudinal profile depth, there are severe salinization and saline soil state, and the soil salt content is accumulated in the surface and bottom. The Na+ and Cl- are the dominant cation and anion, respectively, the distributions of which are consistent with that of salt content. All the salinization indexes, except for soil pH, are of moderate/strong variability. The invasion of Spartina alterniflora results in the increase of soil salt content and salinization degree, the effects of which are mainly determined by the physiological characteristics and the growth years. The degree of soil salinization increased significantly in the aquaculture ponds, which is mainly caused by the use of chemicals. The correlation between soil salt content and Na+, Cl- is particularly significant. From the results of principal component analysis, Na+, Cl-, Ca2+, Mg2+ and SO42- could be used as main diagnostic factors for salinization in typical estuarine area of the Jiaozhou Bay. The effects of NaCl and sulfate on salt content further affect the degree of salinization in the estuarine area.

pH Meter probe assembly

DOEpatents

Hale, C.J.

1983-11-15

An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe. 1 fig.

pH Meter probe assembly

DOEpatents

Hale, Charles J.

1983-01-01

An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe.

Organic matter and salinity modify cadmium soil (phyto)availability.

PubMed

Filipović, Lana; Romić, Marija; Romić, Davor; Filipović, Vilim; Ondrašek, Gabrijel

2018-01-01

Although Cd availability depends on its total concentration in soil, it is ultimately defined by the processes which control its mobility, transformations and soil solution speciation. Cd mobility between different soil fractions can be significantly affected by certain pedovariables such as soil organic matter (SOM; over formation of metal-organic complexes) and/or soil salinity (over formation of metal-inorganic complexes). Phytoavailable Cd fraction may be described as the proportion of the available Cd in soil which is actually accessible by roots and available for plant uptake. Therefore, in a greenhouse pot experiment Cd availability was observed in the rhizosphere of faba bean exposed to different levels of SOM, NaCl salinity (50 and 100mM) and Cd contamination (5 and 10mgkg -1 ). Cd availability in soil does not linearly follow its total concentration. Still, increasing soil Cd concentration may lead to increased Cd phytoavailability if the proportion of Cd 2+ pool in soil solution is enhanced. Reduced Cd (phyto)availability by raised SOM was found, along with increased proportion of Cd-DOC complexes in soil solution. Data suggest decreased Cd soil (phyto)availability with the application of salts. NaCl salinity affected Cd speciation in soil solution by promoting the formation of CdCl n 2-n complexes. Results possibly suggest that increased Cd mobility in soil does not result in its increased availability if soil adsorption capacity for Cd has not been exceeded. Accordingly, chloro-complex possibly operated just as a Cd carrier between different soil fractions and resulted only in transfer between solid phases and not in increased (phyto)availability. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Salinity and Confining Pressure on Hydration-Induced Fracture Propagation and Permeability of Mancos Shale

NASA Astrophysics Data System (ADS)

Zhang, Shifeng; Sheng, James J.

2017-11-01

Low-salinity water imbibition was considered an enhanced recovery method in shale oil/gas reservoirs due to the resulting hydration-induced fractures, as observed at ambient conditions. To study the effect of confining pressure and salinity on hydration-induced fractures, time-elapsed computerized tomography (CT) was used to obtain cross-sectional images of shale cores. Based on the CT data of these cross-sectional images, cut faces parallel to the core axial in the middle of the core and 3D fracture images were also reconstructed. To study the effects of confining pressure and salinity on shale pore fluid flowing, shale permeability was measured with Nitrogen (N2), distilled water, 4% KCl solution, and 8% KCl solution. With confining pressures increased to 2 MPa or more, either in distilled water or in KCl solutions of different salinities, fractures were observed to close instead to propagate at the end of the tests. The intrinsic permeabilities of #1 and #2 Mancos shale cores were 60.0 and 7000 nD, respectively. When tested with distilled water, the permeability of #1 shale sample with 20.0 MPa confining pressure loaded, and #2 shale sample with 2.5 MPa confining pressure loaded, decreased to 0.45 and 15 nD, respectively. Using KCl can partly mitigate shale permeability degradation. Compared to 4% KCl, 8% KCl can decrease more permeability damage. From this point of view, high salinity KCl solution should be required for the water-based fracturing fluid.

Literature Review and Database of Relations Between Salinity and Aquatic Biota: Applications to Bowdoin National Wildlife Refuge, Montana

USGS Publications Warehouse

Gleason, Robert A.; Tangen, Brian A.; Laubhan, Murray K.; Finocchiaro, Raymond G.; Stamm, John F.

2009-01-01

Long-term accumulation of salts in wetlands at Bowdoin National Wildlife Refuge (NWR), Mont., has raised concern among wetland managers that increasing salinity may threaten plant and invertebrate communities that provide important habitat and food resources for migratory waterfowl. Currently, the U.S. Fish and Wildlife Service (USFWS) is evaluating various water management strategies to help maintain suitable ranges of salinity to sustain plant and invertebrate resources of importance to wildlife. To support this evaluation, the USFWS requested that the U.S. Geological Survey (USGS) provide information on salinity ranges of water and soil for common plants and invertebrates on Bowdoin NWR lands. To address this need, we conducted a search of the literature on occurrences of plants and invertebrates in relation to salinity and pH of the water and soil. The compiled literature was used to (1) provide a general overview of salinity concepts, (2) document published tolerances and adaptations of biota to salinity, (3) develop databases that the USFWS can use to summarize the range of reported salinity values associated with plant and invertebrate taxa, and (4) perform database summaries that describe reported salinity ranges associated with plants and invertebrates at Bowdoin NWR. The purpose of this report is to synthesize information to facilitate a better understanding of the ecological relations between salinity and flora and fauna when developing wetland management strategies. A primary focus of this report is to provide information to help evaluate and address salinity issues at Bowdoin NWR; however, the accompanying databases, as well as concepts and information discussed, are applicable to other areas or refuges. The accompanying databases include salinity values reported for 411 plant taxa and 330 invertebrate taxa. The databases are available in Microsoft Excel version 2007 (http://pubs.usgs.gov/sir/2009/5098/downloads/databases_21april2009.xls) and contain

Genetic variation and plasticity of Plantago coronopus under saline conditions

NASA Astrophysics Data System (ADS)

Smekens, Marret J.; van Tienderen, Peter H.

2001-08-01

Phenotypic plasticity may allow organisms to cope with variation in the environmental conditions they encounter in their natural habitats. Salt adaptation appears to be an excellent example of such a plastic response. Many plant species accumulate organic solutes in response to saline conditions. Comparative and molecular studies suggest that this is an adaptation to osmotic stress. However, evidence relating the physiological responses to fitness parameters is rare and requires assessing the potential costs and benefits of plasticity. We studied the response of thirty families derived from plants collected in three populations of Plantago coronopus in a greenhouse experiment under saline and non-saline conditions. We indeed found a positive selection gradient for the sorbitol percentage under saline conditions: plant families with a higher proportion of sorbitol produced more spikes. No effects of sorbitol on fitness parameters were found under non-saline conditions. Populations also differed genetically in leaf number, spike number, sorbitol concentration and percentages of different soluble sugars. Salt treatment led to a reduction of vegetative biomass and spike production but increased leaf dry matter percentage and leaf thickness. Both under saline and non-saline conditions there was a negative trade-off between vegetative growth and reproduction. Families with a high plasticity in leaf thickness had a lower total spike length under non-saline conditions. This would imply that natural selection under predominantly non-saline conditions would lead to a decrease in the ability to change leaf morphology in response to exposure to salt. All other tests revealed no indication for any costs of plasticity to saline conditions.

How Does Salinity Shape Bacterial and Fungal Microbiomes of Alnus glutinosa Roots?

PubMed Central

Thiem, Dominika; Gołębiewski, Marcin; Hulisz, Piotr; Piernik, Agnieszka; Hrynkiewicz, Katarzyna

2018-01-01

Black alder (Alnus glutinosa Gaertn.) belongs to dual mycorrhizal trees, forming ectomycorrhizal (EM) and arbuscular (AM) root structures, as well as represents actinorrhizal plants that associate with nitrogen-fixing actinomycete Frankia sp. We hypothesized that the unique ternary structure of symbionts can influence community structure of other plant-associated microorganisms (bacterial and fungal endophytes), particularly under seasonally changing salinity in A. glutinosa roots. In our study we analyzed black alder root bacterial and fungal microbiome present at two forest test sites (saline and non-saline) in two different seasons (spring and fall). The dominant type of root microsymbionts of alder were ectomycorrhizal fungi, whose distribution depended on site (salinity): Tomentella, Lactarius, and Phialocephala were more abundant at the saline site. Mortierella and Naucoria (representatives of saprotrophs or endophytes) displayed the opposite tendency. Arbuscular mycorrhizal fungi belonged to Glomeromycota (orders Paraglomales and Glomales), however, they represented less than 1% of all identified fungi. Bacterial community structure depended on test site but not on season. Sequences affiliated with Rhodanobacter, Granulicella, and Sphingomonas dominated at the saline site, while Bradyrhizobium and Rhizobium were more abundant at the non-saline site. Moreover, genus Frankia was observed only at the saline site. In conclusion, bacterial and fungal community structure of alder root microsymbionts and endophytes depends on five soil chemical parameters: salinity, phosphorus, pH, saturation percentage (SP) as well as total organic carbon (TOC), and seasonality does not appear to be an important factor shaping microbial communities. Ectomycorrhizal fungi are the most abundant symbionts of mature alders growing in saline soils. However, specific distribution of nitrogen-fixing Frankia (forming root nodules) and association of arbuscular fungi at early stages of

How Does Salinity Shape Bacterial and Fungal Microbiomes of Alnus glutinosa Roots?

PubMed

Thiem, Dominika; Gołębiewski, Marcin; Hulisz, Piotr; Piernik, Agnieszka; Hrynkiewicz, Katarzyna

2018-01-01

Black alder ( Alnus glutinosa Gaertn.) belongs to dual mycorrhizal trees, forming ectomycorrhizal (EM) and arbuscular (AM) root structures, as well as represents actinorrhizal plants that associate with nitrogen-fixing actinomycete Frankia sp. We hypothesized that the unique ternary structure of symbionts can influence community structure of other plant-associated microorganisms (bacterial and fungal endophytes), particularly under seasonally changing salinity in A. glutinosa roots. In our study we analyzed black alder root bacterial and fungal microbiome present at two forest test sites (saline and non-saline) in two different seasons (spring and fall). The dominant type of root microsymbionts of alder were ectomycorrhizal fungi, whose distribution depended on site (salinity): Tomentella , Lactarius , and Phialocephala were more abundant at the saline site. Mortierella and Naucoria (representatives of saprotrophs or endophytes) displayed the opposite tendency. Arbuscular mycorrhizal fungi belonged to Glomeromycota (orders Paraglomales and Glomales), however, they represented less than 1% of all identified fungi. Bacterial community structure depended on test site but not on season. Sequences affiliated with Rhodanobacter , Granulicella , and Sphingomonas dominated at the saline site, while Bradyrhizobium and Rhizobium were more abundant at the non-saline site. Moreover, genus Frankia was observed only at the saline site. In conclusion, bacterial and fungal community structure of alder root microsymbionts and endophytes depends on five soil chemical parameters: salinity, phosphorus, pH, saturation percentage (SP) as well as total organic carbon (TOC), and seasonality does not appear to be an important factor shaping microbial communities. Ectomycorrhizal fungi are the most abundant symbionts of mature alders growing in saline soils. However, specific distribution of nitrogen-fixing Frankia (forming root nodules) and association of arbuscular fungi at early stages

Preparation of non-aggregating aqueous fullerenes in highly saline solutions with a biocompatible non-ionic polymer

NASA Astrophysics Data System (ADS)

Aich, Nirupam; Boateng, Linkel K.; Flora, Joseph R. V.; Saleh, Navid B.

2013-10-01

Size-tunable stable aqueous fullerenes were prepared with different concentrations of biocompatible block-copolymer pluronic (PA) F-127, ranging from 0.001% to 1% (w/v). Size uniformity increased with the increase in PA concentration, yielding optimum 58.8 ± 5.6 and 61.8 ± 5.6 nm nC60s and nC70s, respectively (0.10%w/v PA), as observed using a dynamic light scattering technique. Fullerene aqueous suspensions also manifested enhanced stability in saline solution, Dulbecco’s modified Eagle medium (DMEM), and Roswell Park Memorial Institute (RPMI) culture medium. Transmission electron microscopy was performed to elaborate on the morphology and size specificity of fullerene clusters. Physicochemical characterizations of the suspended fullerenes were performed through UV-vis spectroscopy and electrophoretic mobility measurements. PA molecules showed size restriction by encasement, as observed via molecular dynamics simulations. Such solubilization with controllable size and non-aggregating behavior can facilitate application enhancement and mechanistic environmental and toxicological studies of size-specific fullerenes.

Effects of salinity and flooding on seedlings of cabbage palm (Sabal palmetto).

PubMed

Perry, L; Williams, K

1996-03-01

Sabal palmetto (Walt.) Lodd. ex Schultes (cabbage palm) dominates the coastal limit of many forests in North Florida and Georgia, United States. Changes in saltwater flooding due to sea level rise have been credicted with pushing the coastal limit of cabbage palms inland, eliminating regeneration before causing death of mature trees. Localized freshwater discharge along the coast causes different forest stands to experience tidal flooding with waters that differ in salinity. To elucidate the effect of such variation on regeneration failure under tidal flooding, we examined relative effects of flooding and salinity on the performance of cabbage palm seedlings. We examined the relationship between seedling establishment and degree of tidal inundation in the field, compared the ability of seedlings to withstand tidal flooding at two coastal sites that differed in tidal water salinity, and investigated the physiological responses of cabbage palm seedlings to salinity and flooding in a factorial greenhouse experiment. Seedling survival was inversely correlated with depth and frequency of tidal flooding. Survival of seedlings at a coastal site flooded by waters low in salinity [c. 3 parts per thousand (ppt)] was greater than that at a site flooded by waters higher in salinity (up to 23 ppt). Greenhouse experiments revealed that leaves of seedlings in pots flushed twice daily with salt solutions of 0 ppt and 8 ppt exhibited little difference in midmorning net CO 2 assimilation rates; those flushed with solutions of 15 ppt and 22 ppt, in contrast, had such low rates that they could not be detected. Net CO 2 assimilation rates also declined with increasing salinity for seedlings in pots that were continuously inundated. Continuous root zone inundation appeared to ameliorate effects of salinity on photosynthesis, presumably due to increased salt concentrations and possibly water deficits in periodically flushed pots. Such problems associated with periodic flushing by salt

Sorption of vanadium (V) onto natural soil colloids under various solution pH and ionic strength conditions.

PubMed

Luo, Xiuhua; Yu, Lin; Wang, Changzhao; Yin, Xianqiang; Mosa, Ahmed; Lv, Jialong; Sun, Huimin

2017-02-01

Batch sorption kinetics and isothermal characteristics of V(V) were investigated on three natural soil colloids (manual loessial soil colloid (MSC), aeolian sandy soil colloid (ASC), and cultivated loessial soil colloid (CSC)) under various solution pH and ionic strength (IS) conditions. Colloids were characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). AFM micrographs showed CSC with an aggregated shape with larger particle diameter as compared with ASC and MSC. XRD spectra revealed the presence of different minerals in natural soil colloids including biotite, kaolinite, calcite and quartz, which might contribute to sorption process. The sorption ability decreased with increase of colloidal particle size. The sorption was mainly attributed to complexation by active carboxylate and alcohol groups of colloidal components. Sorption kinetics and isotherms of V(V) onto natural soil colloids were best fitted with Pseudo-second-order and Freundlich models. Langmuir model indicated that sorption capacity of MSC and ASC was comparable (285.7 and 238.1 mg g -1 ); however, CSC exhibited the lowest sorption capacity (41.5 mg g -1 ) due to its larger particle diameter and aggregated shape. The maximum V(V) sorption capacity reached plateau values at a solution pH ranged between 5.0 and 9.0 for MSC and ASC, and 6.0-8.0 for CSC. Sorption capacity of V(V) onto natural soil colloids decreased with increasing IS. Based on result of this study we can conclude that sorption of V(V) onto natural soil colloids is pH- and IS-dependent. These findings provide insights on the remediation of vanadium-contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

[ARTCEREB irrigation and perfusion solution for cerebrospinal surgery: pharmacological assessment using human astrocytes exposed to test solutions].

PubMed

Nishimura, Masuhiro; Doi, Kazuhisa; Enomoto, Riyo; Lee, Eibai; Naito, Shinsaku; Yamauchi, Aiko

2009-09-01

ARTCEREB irrigation and perfusion solution (Artcereb) is a preparation intended for the irrigation and perfusion of the cerebral ventricles, and it is therefore important to evaluate the effects of Artcereb on brain cells. In vitro assessment of the effects of Artcereb in cell cultures of human fetal astrocytes was conducted in comparison with normal saline and lactated Ringer's solution. The effects of exposure to Artcereb were evaluated based on microscopic images of the mitochondria stained with rhodamine 123. The effects of exposure to Artcereb on cell function were also evaluated by quantitative analysis of mitochondrial activity based on rhodamine 123 and (3)H-thymidine incorporation. Morphological changes in nuclear structure were also evaluated. The results of the present study showed that cell function in cell cultures of human astrocytes was relatively unaffected by exposure to Artcereb as compared with normal saline or lactated Ringer's solution, suggesting that Artcereb has less effect on brain cells than normal saline or lactated Ringer's solution when used for the irrigation or perfusion of the cerebral ventricles.

Soil salinization in the agricultural lands of Rhodope District, northeastern Greece.

PubMed

Pisinaras, V; Tsihrintzis, V A; Petalas, C; Ouzounis, K

2010-07-01

The objective of this study was to identify seasonal and spatial trends and soil salinization patterns in a part of Rhodope District irrigated land, northeastern Greece, located east of Vistonis Lagoon. The study area is irrigated from a coastal aquifer, where salt water intrusion occurs because of extensive groundwater withdrawals. Fourteen monitoring sites were established in harvest fields in the study area, where soil samples were collected. Electrical conductivity (ECe), pH, and ion concentrations were determined in the saturated paste extract of the soil samples in the laboratory using standard methods. A clear tendency was observed for ECe to increase from April to September, i.e., within the irrigation period, indicating the effect of saline groundwater to soil. In the last years, the change from moderately sensitive (e.g., corn) to moderately tolerant crops (e.g., cotton) in the south part of the study area indicates the impacts of soil salinity. The study proposes management methods to alleviate this problem.

Impact Assessment of Salinization Affected Soil on Greenhouse Crops using SALTMED

NASA Astrophysics Data System (ADS)

Pappa, Polyxeni; Daliakopoulos, Ioannis; Tsanis, Ioannis; Varouchakis, Emmanouil

2015-04-01

Here we assess the effects of soil salinization on greenhouse crops and the potential benefits of rainwater harvesting as a soil amelioration technology. The study deals with the following scenarios: (a) variation of irrigation water salinity from 3,000 μS/cm to 500 μS/cm through mixing with rainwater, (b) crop substitution for increased tolerance and (c) climatic variability to account for the impact of climate change. In order to draw meaningful conclusions, a model that takes into account vegetation interaction, soil, irrigation water and climate variables is required. The SALTMED model is a reliable and tested physical process model that simulates evapotranspiration, plant water uptake, water and solute transport to estimate crop yield and biomass production under all irrigation systems. SALTMED is tested with the above scenarios in the RECARE FP7 Project Case Study of Timpaki, in the Island of Crete, Greece. Simulations are conducted for typical cultivations of Solanum lycopersicum, Capsicum anuumm and Solanum melongena. Preliminary results indicate the optimal combination from a set of solutions concerning the soil and water parameters can be beneficial against the salinization threat. Future research includes the validation of the results with field experiments. Keywords: salinization, greenhouse, tomato, SALTMED, rainwater, RECARE

Cold physical plasma treated buffered saline solution as effective agent against pancreatic cancer cells.

PubMed

Bekeschus, Sander; Kading, Andre; Schroder, Tim; Wende, Kristian; Hackbarth, Christine; Liedtke, Kim Rouven; van der Linde, Julia; von Woedtke, Thomas; Heidecke, Claus-Dieter; Partecke, Lars-Ivo

2018-05-07

Cold physical plasma has been suggested as a new anticancer tool recently. However, direct use of plasma is limited to visible tumors and in some clinical situations not feasible. This includes repetitive treatment of peritoneal metastases which commonly occur in advanced gastrointestinal cancer and in pancreatic cancer in particular. In case of diffuse intraperitoneal metastatic spread Hyperthermic Intraperitoneal Intraoperative Chemotherapy (HIPEC) is used as therapeutic approach. Plasma treated solutions may combine their suspected systemic non-toxic characteristics with the anticancer effects of HIPEC. Previous work has provided evidence for an anti-cancer efficacy of plasma treated cell culture medium but the clinical relevance of such an approach is low due to its complex formulation and lack of medical accreditation. Therefore, plasma treated phosphate-buffered saline (PBS) which closely resembles medically certified solutions was investigated for its cytotoxic effect on 2D monolayer murine pancreatic cancer cells in vitro. It significantly decreased cancer cell metabolisms and proliferation whereas plasma treated Dulbecco's Modified Eagle Medium had no effect. Moreover, tumor cell growth attenuation was significantly higher when compared to syngeneic primary murine fibroblasts. Both results were confirmed in a human pancreatic cancer cell line. Finally, plasma treated PBS also decreased tumor sizes of pancreatic tumors in the TUM-CAM model in a three-dimensional manner, and induction of apoptosis was found to be responsible for all anticancer effects identified. Altogether, plasma treated PBS inhibited cell growth in 2D and 3D models of cancer. These results may help facilitating the development of new plasma derived anticancer agent with clinical relevance in the future. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Analytical Solution for Interface Flow to a Sink With an Upconed Saline Water Lens: Strack's Regimes Revisited

NASA Astrophysics Data System (ADS)

Kacimov, A. R.; Obnosov, Y. V.

2018-01-01

A study is made of a steady, two-dimensional groundwater flow with a horizontal well (drain), which pumps out freshwater from an aquifer sandwiched between a horizontal bedrock and ponded soil surface, and containing a lens-shaped static volume of a heavier saline water (DNAPL-dense nonaqueous phase liquid) as a free surface. For flow toward a line sink, an explicit analytical solution is obtained by a conformal mapping of the hexagon in the complex potential plane onto a reference plane and the Keldysh-Sedov integral representation of a mixed boundary-value problem for a complex physical coordinate. The interface is found as a function of the pumping rate, the well locus, the ratio of liquid densities, and the hydraulic heads at the soil surface and in the well. The shape with two inflexion points and fronts varies from a small-thickness bedrock-spread pancake to a critical curvilinear triangle, which cusps toward the sink. The problem is mathematically solvable in a relatively narrow band of geometric and hydraulic parameters. A similar analytic solution for a static heavy bubble confined by a closed-curve interface (no contact with the bedrock) is outlined as an illustration of the method to solve a mixed boundary-value problem.

Improved reliability of pH measurements.

PubMed

Spitzer, Petra; Werner, Barbara

2002-11-01

Measurements of pH are performed on a large scale at laboratory level, and in industry. To meet the quality-control requirements and other technical specifications there is a need for traceability in measurement results. The prerequisite for the international acceptance of analytical data is reliability. To measure means to compare. Comparability entails use of recognised references to which the standard buffer solutions used for calibration of pH meter-electrode assemblies can be traced. The new recommendation on the measurement of pH recently published as a provisional document by the International Union on Pure and Applied Chemistry (IUPAC) enables traceability for measured pH values to a conventional reference frame which is recognised world-wide. The primary method for pH will be described. If analytical data are to be accepted internationally it is necessary to demonstrate the equivalence of the national traceability structures, including national measurement standards. For the first time key comparisons for pH have been performed by the Consultative Committee for Amount of Substance (CCQM, set up by the International Bureau of Weights and Measures, BIPM) to assess the equivalence of the national measurement procedures used to determine the pH of primary standard buffer solutions. The results of the first key comparison on pH CCQM-K9, and other international initiatives to improve the consistency of the results of measurement for pH, are reported.

Comparison of 7.2% hypertonic saline - 6% hydroxyethyl starch solution and 6% hydroxyethyl starch solution after the induction of anesthesia in patients undergoing elective neurosurgical procedures

PubMed Central

Shao, Liujiazi; Wang, Baoguo; Wang, Shuangyan; Mu, Feng; Gu, Ke

2013-01-01

OBJECTIVE: The ideal solution for fluid management during neurosurgical procedures remains controversial. The aim of this study was to compare the effects of a 7.2% hypertonic saline - 6% hydroxyethyl starch (HS-HES) solution and a 6% hydroxyethyl starch (HES) solution on clinical, hemodynamic and laboratory variables during elective neurosurgical procedures. METHODS: Forty patients scheduled for elective neurosurgical procedures were randomly assigned to the HS-HES group or the HES group. After the induction of anesthesia, patients in the HS-HES group received 250 mL of HS-HES (500 mL/h), whereas the patients in the HES group received 1,000 mL of HES (1000 mL/h). The monitored variables included clinical, hemodynamic and laboratory parameters. Chictr.org: ChiCTR-TRC-12002357 RESULTS: The patients who received the HS-HES solution had a significant decrease in the intraoperative total fluid input (p<0.01), the volume of Ringer's solution required (p<0.05), the fluid balance (p<0.01) and their dural tension scores (p<0.05). The total urine output, blood loss, bleeding severity scores, operation duration and hemodynamic variables were similar in both groups (p>0.05). Moreover, compared with the HES group, the HS-HES group had significantly higher plasma concentrations of sodium and chloride, increasing the osmolality (p<0.01). CONCLUSION: Our results suggest that HS-HES reduced the volume of intraoperative fluid required to maintain the patients undergoing surgery and led to a decrease in the intraoperative fluid balance. Moreover, HS-HES improved the dural tension scores and provided satisfactory brain relaxation. Our results indicate that HS-HES may represent a new avenue for volume therapy during elective neurosurgical procedures. PMID:23644851

[Preliminary establishment of cytological examination and the normal reference values for hypertonic saline solution-induced sputum of healthy children in Guangzhou].

PubMed

Chen, De-hui; Zhong, Guo-yu; Luo, Wei; Chen, Qiao-li; Chen, Ru-chong; Lin, Yu-neng; Pan, Xiao-an; Li, Jin-ying; Wu, Shang-zhi; Lai, Ke-fang; Zhong, Nan-shan

2012-07-01

To establish the method of cytological examination and the normal reference values for hypertonic saline solution-induced sputum of healthy children (age range from 5 to 15 years) with physical examination in Guangzhou. A total of 352 children, 5 to 15 years old, were enrolled from primary school and middle school in Guangzhou from January to December, 2010. All subjects completed a standardized questionnaire on the presence of respiratory, allergic symptoms and family history, the medical history and the physical examination was performed by doctors, lung function (forced expiratory volume at 1 s in predicted normal, FEV(1)%) was determined. There were 266 healthy children (137 males, 129 females) who were selected and undergone hypertonic saline solution induction of sputum, and cytological examination was performed. Hypertonic saline (5%) was nebulized and inhaled for 15 - 30 min. No expectoration within 30 min was defined as failure, and the procedure was terminated. The part of opaque and higher density sputum samples was detected by cytology. The proportion of neutrophils, lymphocytes, eosinophils, macrophages and monocytes was calculated. This study was approved by the institutional Ethics Review Committee of First Affiliated Hospital of Guangzhou Medical College. Informed consent was obtained from the legal guardians of all participants following a detailed description of the purpose and potential benefits of the study. There were 175 subjects' induced sputum specimens (175/266, 65.8%), non-qualified sputum samples were obtained from 16 of the subjects. The proportions of median (IQR) of lymphocytes were 0.012 (0.020), 95%CI were ranged from 0.015 to 0.022; neutrophils 0.207 (0.330), 95%CI 0.266 - 0.356 macrophages 0.761 (0.327), 95%CI 0.607 - 0.699; eosinophils 0.004 (0.019), 95%CI 0.013 - 0.022. There were no significant differences in proportions of cytological findings of female or male, different age groups and second-hand smoking or not (all P > 0

Radiation chemistry of physiological saline reinvestigated: evidence that chloride-derived intermediates play a key role in cytotoxicity.

PubMed

Saran, M; Bors, W

1997-01-01

Contrary to common belief, hydrogen peroxide (H2O2) and hypochlorite (HOCl) are not produced continuously and independently during the irradiation of buffer solution containing chloride. Different buildup and decay reactions are involved in a complex interaction of these substances during irradiation. Which of the species predominates is determined by the parameters of the solution. The amount of either compound detectable after irradiation depends on the dissolved gas (O2, N2O or N2), on the pH value and to some extent on the presence of catalytic metals: Under slightly acidic conditions, low oxygen content and high generation rates of OH radicals, the only detectable species is hypochlorite; at high oxygen content and at pH values in the physiological range, hydrogen peroxide is the main detectable product. However, H2O2 and HOCl react with each other in a pH-dependent way, yielding the stable products O2 and Cl-. This reaction limits the expected lifetime of both species in aqueous solution to some tens of seconds. Therefore, analysis of the sample solution after irradiation determines only the substance that was present in greater relative concentration at the termination of irradiation. Such analysis, however, does not allow conclusions about the processes that occurred during irradiation. We have investigated the decay and formation reactions of H2O2 and HOCl under all relevant irradiation conditions and found evidence that the formation and further reaction of HOCl-, the precursor of HOCl, is of central importance even in cases where no significant amounts of H2O2 or HOCl are detectable after irradiation. We discuss the consequences of these results for the cytotoxicity observed after irradiation of cells suspended in physiological saline and conclude that analogous processes must also be relevant for irradiations under in vivo conditions.

Reexamining ultrafiltration and solute transport in groundwater

NASA Astrophysics Data System (ADS)

Neuzil, C. E.; Person, Mark

2017-06-01

Geologic ultrafiltration—slowing of solutes with respect to flowing groundwater—poses a conundrum: it is consistently observed experimentally in clay-rich lithologies, but has been difficult to identify in subsurface data. Resolving this could be important for clarifying clay and shale transport properties at large scales as well as interpreting solute and isotope patterns for applications ranging from nuclear waste repository siting to understanding fluid transport in tectonically active environments. Simulations of one-dimensional NaCl transport across ultrafiltering clay membrane strata constrained by emerging data on geologic membrane properties showed different ultrafiltration effects than have often been envisioned. In relatively high-permeability advection-dominated regimes, salinity increases occurred mostly within membrane units while their effluent salinity initially fell and then rose to match solute delivery. In relatively low-permeability diffusion-dominated regimes, salinity peaked at the membrane upstream boundary and effluent salinity remained low. In both scenarios, however, only modest salinity changes (up to ˜3 g L-1) occurred because of self-limiting tendencies; membrane efficiency declines as salinity rises, and although sediment compaction increases efficiency, it is also decreases permeability and allows diffusive transport to dominate. It appears difficult for ultrafiltration to generate brines as speculated, but widespread and less extreme ultrafiltration effects in the subsurface could be unrecognized. Conditions needed for ultrafiltration are present in settings that include topographically-driven flow systems, confined aquifer systems subjected to injection or withdrawal, compacting basins, and accretionary complexes.

Reexamining ultrafiltration and solute transport in groundwater

USGS Publications Warehouse

Neuzil, Christopher E.; Person, Mark

2017-01-01

Geologic ultrafiltration—slowing of solutes with respect to flowing groundwater—poses a conundrum: it is consistently observed experimentally in clay-rich lithologies, but has been difficult to identify in subsurface data. Resolving this could be important for clarifying clay and shale transport properties at large scales as well as interpreting solute and isotope patterns for applications ranging from nuclear waste repository siting to understanding fluid transport in tectonically active environments. Simulations of one-dimensional NaCl transport across ultrafiltering clay membrane strata constrained by emerging data on geologic membrane properties showed different ultrafiltration effects than have often been envisioned. In relatively high-permeability advection-dominated regimes, salinity increases occurred mostly within membrane units while their effluent salinity initially fell and then rose to match solute delivery. In relatively low-permeability diffusion-dominated regimes, salinity peaked at the membrane upstream boundary and effluent salinity remained low. In both scenarios, however, only modest salinity changes (up to ∼3 g L−1) occurred because of self-limiting tendencies; membrane efficiency declines as salinity rises, and although sediment compaction increases efficiency, it is also decreases permeability and allows diffusive transport to dominate. It appears difficult for ultrafiltration to generate brines as speculated, but widespread and less extreme ultrafiltration effects in the subsurface could be unrecognized. Conditions needed for ultrafiltration are present in settings that include topographically-driven flow systems, confined aquifer systems subjected to injection or withdrawal, compacting basins, and accretionary complexes.

Control of continuous phase PH using visible light to activate PH-dependent fibers and gels in a controlled and reversible manner

NASA Astrophysics Data System (ADS)

Zirino, Albert

1994-08-01

A transparent polyelectrolyte fiber or gel, such as crosslinked polyacrylic acid, which contracts and expands upon the addition of an acid or base to an aqueous medium solution, is placed in the same solution with a pH dependent dye, a colored photochromatic indicator dye. The dye preferably has a pAa value that is the same as the pH at a null contraction point of the fiber. By irradiating the solution with light of a wavelength of the absorption band of either the acid or base form of the dye, the solution pH is made to change, and the fiber is made to expand or contract, depending upon the wavelength. Thus, light energy is readily converted to work energy and may be used to power a pump, for example or an artificial muscle can be powered via an optical fiber.

Effect of Hypertonic Saline Infusion versus Normal Saline on Serum NGAL and Cystatin C Levels in Patients Undergoing Coronary Artery Bypass Graft

PubMed Central

Yousefshahi, Fardin; Bashirzadeh, Mona; Abdollahi, Mohammad; Mojtahedzadeh, Mojtaba; Salehiomran, Abbass; Jalali, Arash; Mazandarani, Mahnaz; Zaare, Elmira; Ahadi, Mehdi

2013-01-01

Background: Acute kidney injury (AKI) is a common and life-threatening complication following coronary artery bypass graft (CABG). Neutrophil gelatinase-associated lipocalin (NGAL) and Cystatin C have shown to be good predictive factors for AKI. Recently, there has been a growing interest in the use of hypertonic saline in cardiac operations. The purpose of this study was to evaluate the prophylactic anti-inflammatory effect of hypertonic saline (Group A) infusion versus normal saline (Group B) on serum NGAL and Cystatin C levels as the two biomarkers of AKI in CABG patients. Methods: This randomized double-blinded clinical trial recruited 40 patients undergoing CABG in Tehran Heart Center, Tehran, Iran. After applying exclusion criteria, the effects of preoperative hypertonic saline (294 meq Na) versus normal saline (154 meq Na) infusion on serum NGAL and Cystatin C levels were investigated in three intervals: before surgery and 24 and 48 hours postoperatively. The probable intraoperative or postoperative confounders, including pump time, cross-clamp time, heart rate, systolic and diastolic blood pressures, central venous pressure, arterial pH, partial pressure of arterial oxygen, fraction of inspired oxygen, blood sugar, Na, K, Mg, hemoglobins, white blood cells, hematocrits, and platelets, were recorded and compared between the two groups of study. Results: The study population comprised 40 patients, including 25 (62.5%) males, at a, mean age ± SD of 61.75 ± 8.13 years. There were no statistically significant differences between the patients’ basic, intraoperative, and postoperative characteristics, including intraoperative and postoperative hemodynamic variables and supports such as inotropic use. Intra-aortic balloon pump use and mortality were not seen in our cases. Three patients in the normal saline group and one patient in the hypertonic saline group had serum NGAL levels greater than 400 ng/ml. Moreover, 10 patients in Group A and 17 patients in group

Effect of Hypertonic Saline Infusion versus Normal Saline on Serum NGAL and Cystatin C Levels in Patients Undergoing Coronary Artery Bypass Graft.

PubMed

Yousefshahi, Fardin; Bashirzadeh, Mona; Abdollahi, Mohammad; Mojtahedzadeh, Mojtaba; Salehiomran, Abbass; Jalali, Arash; Mazandarani, Mahnaz; Zaare, Elmira; Ahadi, Mehdi

2013-01-01

Acute kidney injury (AKI) is a common and life-threatening complication following coronary artery bypass graft (CABG). Neutrophil gelatinase-associated lipocalin (NGAL) and Cystatin C have shown to be good predictive factors for AKI. Recently, there has been a growing interest in the use of hypertonic saline in cardiac operations. The purpose of this study was to evaluate the prophylactic anti-inflammatory effect of hypertonic saline (Group A) infusion versus normal saline (Group B) on serum NGAL and Cystatin C levels as the two biomarkers of AKI in CABG patients. This randomized double-blinded clinical trial recruited 40 patients undergoing CABG in Tehran Heart Center, Tehran, Iran. After applying exclusion criteria, the effects of preoperative hypertonic saline (294 meq Na) versus normal saline (154 meq Na) infusion on serum NGAL and Cystatin C levels were investigated in three intervals: before surgery and 24 and 48 hours postoperatively. The probable intraoperative or postoperative confounders, including pump time, cross-clamp time, heart rate, systolic and diastolic blood pressures, central venous pressure, arterial pH, partial pressure of arterial oxygen, fraction of inspired oxygen, blood sugar, Na, K, Mg, hemoglobins, white blood cells, hematocrits, and platelets, were recorded and compared between the two groups of study. The study population comprised 40 patients, including 25 (62.5%) males, at a, mean age ± SD of 61.75 ± 8.13 years. There were no statistically significant differences between the patients' basic, intraoperative, and postoperative characteristics, including intraoperative and postoperative hemodynamic variables and supports such as inotropic use. Intra-aortic balloon pump use and mortality were not seen in our cases. Three patients in the normal saline group and one patient in the hypertonic saline group had serum NGAL levels greater than 400 ng/ml. Moreover, 10 patients in Group A and 17 patients in group B showed a rise in serum

Agglomeration of Luminescent Porous Silicon Nanoparticles in Colloidal Solutions.

PubMed

Herynková, Kateřina; Šlechta, Miroslav; Šimáková, Petra; Fučíková, Anna; Cibulka, Ondřej

2016-12-01

We have prepared colloidal solutions of clusters composed from porous silicon nanoparticles in methanol, water and phosphate-buffered saline (PBS). Even if the size of the nanoclusters is between 60 and 500 nm, due to their highly porous "cauliflower"-like structure, the porous silicon nanoparticles are composed of interconnected nanocrystals having around 2.5 nm in size and showing strong visible luminescence in the orange-red spectral region (centred at 600-700 nm). Hydrophilic behaviour and good solubility of the nanoclusters in water and water-based solutions were obtained by adding hydrogen peroxide into the etching solution during preparation and 16 min long after-bath in hydrogen peroxide. By simple filtration of the solutions with syringe filters, we have extracted smaller nanoclusters with sizes of approx. 60-70 nm; however, these nanoclusters in water and PBS solution (pH neutral) are prone to agglomeration, as was confirmed by zeta potential measurements. When the samples were left at ambient conditions for several weeks, the typical nanocluster size increased to approx. 330-400 nm and then remained stable. However, both freshly filtered and aged samples (with agglomerated porous silicon nanoparticles) of porous silicon in water and PBS solutions can be further used for biological studies or as luminescent markers in living cells.

Impact of long-term salinity exposure in anaerobic membrane bioreactors treating phenolic wastewater: Performance robustness and endured microbial community.

PubMed

Muñoz Sierra, Julian D; Oosterkamp, Margreet J; Wang, Wei; Spanjers, Henri; van Lier, Jules B

2018-05-07

Industrial wastewaters are becoming increasingly associated with extreme conditions such as the presence of refractory compounds and high salinity that adversely affect biomass retention or reduce biological activity. Hence, this study evaluated the impact of long-term salinity increase to 20 gNa + .L -1 on the bioconversion performance and microbial community composition in anaerobic membrane bioreactors treating phenolic wastewater. Phenol removal efficiency of up to 99.9% was achieved at 14 gNa + .L -1 . Phenol conversion rates of 5.1 mgPh.gVSS -1 .d -1 , 4.7 mgPh.gVSS -1 .d -1 , and 11.7 mgPh.gVSS -1 .d -1 were obtained at 16 gNa + .L -1 ,18 gNa + .L -1 and 20 gNa + .L -1 , respectively. The AnMBR's performance was not affected by short-term step-wise salinity fluctuations of 2 gNa + .L -1 in the last phase of the experiment. It was also demonstrated in batch tests that the COD removal and methane production rate were higher at a K + :Na + ratio of 0.05, indicating the importance of potassium to maintain the methanogenic activity. The salinity increase adversely affected the transmembrane pressure likely due to a particle size decrease from 185 μm at 14 gNa + .L -1 to 16 μm at 20 gNa + .L -1 . Microbial community was dominated by bacteria belonging to the Clostridium genus and archaea by Methanobacterium and Methanosaeta genus. Syntrophic phenol degraders, such as Pelotomaculum genus were found to be increased when the maximum phenol conversion rate was attained at 20 gNa + .L -1 . Overall, the observed robustness of the AnMBR performance indicated an endured microbial community to salinity changes in the range of the sodium concentrations applied. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characterization of zinc oxide thin film for pH detector

NASA Astrophysics Data System (ADS)

Hashim, Uda; Fathil, M. F. M.; Arshad, M. K. Md; Gopinath, Subash C. B.; Uda, M. N. A.

2017-03-01

This paper presents the fabrication process of the zinc oxide thin films for using to act as pH detection by using different PH solution. Sol-gel solution technique is used for preparing zinc oxide seed solution, followed by metal oxide deposition process by using spin coater on the silicon dioxide. Silicon dioxide layer is grown on the silicon wafer, then, ZnO seed solution is deposited on the silicon layer, baked, and annealing process carried on to undergo the characterization of its surface morphology, structural and crystalline phase. Electrical characterization is showed by using PH 4, 7, and 10 is dropped on the surface of the die, in addition, APTES solution is used as linker and also as a references of the electrical characterization.

Graft preservation solutions in cardiovascular surgery.

PubMed

Winkler, Bernhard; Reineke, David; Heinisch, Paul Philip; Schönhoff, Florian; Huber, Christoph; Kadner, Alexander; Englberger, Lars; Carrel, Thierry

2016-08-01

Vein grafts are still the most commonly used graft material in cardiovascular surgery and much effort has been spent in recent years on investigating the optimal harvesting technique. One other related topic of similar importance remained more or less an incidental one. The storage solutions of vein grafts following procurement and prior to implantation are, despite their assumed impact, a relatively neglected theme. There is no doubt that the endothelium plays a key role in long-term patency of vein grafts, but the effects of the different storage solutions on the endothelium remain unclear : In a review of the literature, we could find 20 specific papers that addressed the question, of which the currently available preservation solutions are superior, harmless, damaging or ineffective. The focus lies on saline and autologous whole blood. Besides these two storage media, novel or alternative solutions have been investigated with surprising findings. In addition, a few words will be spent on potential alternatives and novel solutions on the market. As there is currently no randomized clinical trial regarding saline versus autologous whole blood available, this review compares all previous studies and methods of analysis to provide a certain level of evidence on this topic. In summary, saline has negative effects on the endothelial layers and therefore may compromise graft patency. Related factors, such as distension pressure, may outbalance the initial benefit of autologous whole blood or storage solutions and intensify the harmful effects of warm saline. In addition, there is no uniform consent on the superiority of autologous whole blood for vein graft storage. This may open the door to alternatives such as the University of Wisconsin solution or one of the specific designed storage solutions like TiProtec™ or Somaluthion™. Whether these preservation solutions are superior or advantageous remains the subject of further studies. © The Author 2016. Published

Cerebral effects of resuscitation with hypertonic saline and a new low-sodium hypertonic fluid in hemorrhagic shock and head injury.

PubMed

Sheikh, A A; Matsuoka, T; Wisner, D H

1996-07-01

A 2400-mOsm/L hypertonic solution (isosal) with a lower sodium content, compared with conventional 7.5% hypertonic saline, was formulated using a mixture of sodium chloride, glucose, and mixed amino acids. This solution was developed to minimize hypernatremia during resuscitation. We assessed the effects of isosal on hemodynamics, brain edema, and plasma sodium concentration after head injury associated with hemorrhagic shock. DESIGN. Prospective, randomized laboratory study. University research laboratory. Twenty-one adult female Suffolk sheep, weighing 39 to 49 kg. Animals were subjected to a 2-hr period of hemorrhagic shock to a mean arterial pressure (MAP) of 40 to 45 mm Hg in the presence of a freeze injury to the cerebral cortex. The hemorrhagic shock/head injury phase was followed by 2 hrs of resuscitation with isosal, a new 2400-mosm/L low-sodium hypertonic fluid, 2400 mosm/L of 7.5% hypertonic saline, or lactated Ringer's solution. Initial resuscitation was with a bolus injection of 8 mL/kg of the study solution; subsequent resuscitation in all three groups was with lactated Ringer's solution as needed to maintain baseline cardiac output. Serial hemodynamics, intracranial pressure, electrolytes, and osmolarity were measured. AT the end of resuscitation, the animals were killed and brain water content (mL H2O/g dry weight) of the injured and uninjured areas was determined. Resuscitation volumes were significantly lower in the isosal (19 +/- 5 mL/kg) and 7.5% hypertonic saline (14 +/- 2 mL/mg) groups compared with the lactated Ringer's solution (35 +/- 5 mL/kg) group. Intracranial pressure after 2 hrs of resuscitation was significantly lower in the isosal (7 +/- 1 mm Hg) and hypertonic saline groups (4 +/- 1 mm Hg). Water content in all areas of the brain was significantly lower in the hypertonic saline group compared with the lactated Ringer's solution group. Brain water content in the isosal group was lower than in the lactated Ringer's solution group only

FT-Raman study of quinine aqueous solutions with varying pH: 2D correlation study

NASA Astrophysics Data System (ADS)

Wesełucha-Birczyńska, Aleksandra

2007-01-01

Quinine (C 20H 24N 2O 2) is one of the best known, for its antimalarial activity, Cinchona alkaloid. In the current study 2D correlation method was applied to analyze FT-Raman spectra of quinine aqueous solutions with varying pH, which was regarded as an external perturbation. Protonation appears to be the main cause leading to the emergence of cross peaks in the synchronous and asynchronous correlation maps. One should know that protonation process is an important step associated with quinine antimalarial activity. Methoxy group manifests its presence by creation of the respective correlation peaks and seems to be significant for quinine mode of action.

Evolution of the electrical resistivity anisotropy during saline tracer tests: insights from geoelectrical milli-fluidic experiments

NASA Astrophysics Data System (ADS)

Jougnot, D.; Jimenez-Martinez, J.; Legendre, R.; Le Borgne, T.; Meheust, Y.; Linde, N.

2017-12-01

The use of time-lapse electrical resistivity tomography has been largely developed in environmental studies to remotely monitor water saturation and contaminant plumes migration. However, subsurface heterogeneities, and corresponding preferential transport paths, yield a potentially large anisotropy in the electrical properties of the subsurface. In order to study this effect, we have used a newly developed geoelectrical milli-fluidic experimental set-up with a flow cell that contains a 2D porous medium consisting of a single layer of cylindrical solid grains. We performed saline tracer tests under full and partial water saturations in that cell by jointly injecting air and aqueous solutions with different salinities. The flow cell is equipped with four electrodes to measure the bulk electrical resistivity at the cell's scale. The spatial distribution of the water/air phases and the saline solute concentration field in the water phase are captured simultaneously with a high-resolution camera by combining a fluorescent tracer with the saline solute. These data are used to compute the longitudinal and transverse effective electrical resistivity numerically from the measured spatial distributions of the fluid phases and the salinity field. This approach is validated as the computed longitudinal effective resistivities are in good agreement with the laboratory measurements. The anisotropy in electrical resistivity is then inferred from the computed longitudinal and transverse effective resistivities. We find that the spatial distribution of saline tracer, and potentially air phase, drive temporal changes in the effective resistivity through preferential paths or barriers for electrical current at the pore scale. The resulting heterogeneities in the solute concentrations lead to strong anisotropy of the effective bulk electrical resistivity, especially for partially saturated conditions. Therefore, considering the electrical resistivity as a tensor could improve our

Programmable pH buffers

DOEpatents

Gough, Dara Van; Huber, Dale L.; Bunker, Bruce C.; Roberts, Mark E.

2017-01-24

A programmable pH buffer comprises a copolymer that changes pK.sub.a at a lower critical solution temperature (LCST) in water. The copolymer comprises a thermally programmable polymer that undergoes a hydrophobic-to-hydrophilic phase change at the LCST and an electrolytic polymer that exhibits acid-base properties that are responsive to the phase change. The programmable pH buffer can be used to sequester CO.sub.2 into water.

Linking water and carbon cycles through salinity observed from space

NASA Astrophysics Data System (ADS)

Xie, X.; Liu, W. T.

2017-12-01

The association of ocean surface salinity in global hydrological cycle and climate change has been traditionally studied through the examination of its tendency and advection as manifestation of ocean's heat and water fluxes with the atmosphere. The variability of surface heat and water fluxes are linked to top of atmosphere radiation, whose imbalance is the main cause of global warming. Besides the link of salinity to greenhouse warming through water balance, this study will focus on the effect of changing salinity on carbon dioxide flux between the ocean and the atmosphere. We have built statistical models to estimate the partial pressure of carbon dioxide (pCO2) and ocean acidification (in terms of total alkalinity and pH) using spacebased data. PCO2 is a critical parameter governing ocean as source and sink of the accumulated greenhouse gas in the atmosphere. The exchange also causes ocean acidification, which is detrimental to marine lives and ecology. Before we had sufficient spacebased salinity measurements coincident with in situ pCO2 measurement, we trained our statistical models to use satellite sea surface temperature and chlorophyll, with one model using salinity climatology and the other without. We found significant differences between the two models in regions of strong water input through river discharge and surface water flux. The pCO2 output follows the seasonal salinity advection of the Amazon outflow. The seasonal salinity advection between Bay of Bengal and Arabian Sea are followed by change of pCO2 and total alkalinity. At shorter time scales, the signatures of rain associated with intraseasonal organized convection of summer monsoon can be detected. We have observed distribution agreement of among pCO2, surface salinity, and surface water flux for variation from a few days to a few years under the Pacific ITCZ; the agreement varies slightly with season and longitudes and the reason is under study.

Immersing lungs in hydrogen-rich saline attenuates lung ischaemia-reperfusion injury.

PubMed

Takahashi, Mamoru; Chen-Yoshikawa, Toyofumi F; Saito, Masao; Tanaka, Satona; Miyamoto, Ei; Ohata, Keiji; Kondo, Takeshi; Motoyama, Hideki; Hijiya, Kyoko; Aoyama, Akihiro; Date, Hiroshi

2017-03-01

Anti-oxidant effects of hydrogen have been reported in studies examining ischaemia-reperfusion injury (IRI). In this study, we evaluated the therapeutic efficacy of immersing lungs in hydrogen-rich saline on lung IRI. Lewis rats were divided into three groups: (i) sham, (ii) normal saline and (iii) hydrogen-rich saline. In the first experiment, the left thoracic cavity was filled with either normal saline or hydrogen-rich saline for 1 h. Then, we measured the hydrogen concentration in the left lung using a sensor gas chromatograph ( N = 3 per group). In the second experiment, lung IRI was induced by occlusion of the left pulmonary hilum for 1 h, followed by reperfusion for 3 h. During the ischaemic period, the left thoracic cavity was filled with either normal saline or hydrogen-rich saline. After reperfusion, we assessed lung function, histological changes and cytokine production ( N = 5-7 per group). Immersing lungs in hydrogen-rich saline resulted in an elevated hydrogen concentration in the lung (6.9 ± 2.9 μmol/1 g lung). After IRI, pulmonary function (pulmonary compliance and oxygenation levels) was significantly higher in the hydrogen-rich saline group than in the normal saline group ( P  < 0.05). Similarly, pro-inflammatory cytokine levels (interleukin-1β and interleukin-6) in the left lung were significantly lower in the hydrogen-rich saline group than in the normal saline group ( P  < 0.05). Immersing lungs in hydrogen-rich saline delivered hydrogen into the lung and consequently attenuated lung IRI. Hydrogen-rich solution appears to be a promising approach to managing lung IRI. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Bacteriophage Infectivity Against Pseudomonas aeruginosa in Saline Conditions

PubMed Central

Scarascia, Giantommaso; Yap, Scott A.; Kaksonen, Anna H.; Hong, Pei-Ying

2018-01-01

Pseudomonas aeruginosa is a ubiquitous member of marine biofilm, and reduces thiosulfate to produce toxic hydrogen sulfide gas. In this study, lytic bacteriophages were isolated and applied to inhibit the growth of P. aeruginosa in planktonic mode at different temperature, pH, and salinity. Bacteriophages showed optimal infectivity at a multiplicity of infection of 10 in saline conditions, and demonstrated lytic abilities over all tested temperature (25, 30, 37, and 45°C) and pH 6–9. Planktonic P. aeruginosa exhibited significantly longer lag phase and lower specific growth rates upon exposure to bacteriophages. Bacteriophages were subsequently applied to P. aeruginosa-enriched biofilm and were determined to lower the relative abundance of Pseudomonas-related taxa from 0.17 to 5.58% in controls to 0.01–0.61% in treated microbial communities. The relative abundance of Alphaproteobacteria, Pseudoalteromonas, and Planococcaceae decreased, possibly due to the phage-induced disruption of the biofilm matrix. Lastly, when applied to mitigate biofouling of ultrafiltration membranes, bacteriophages were determined to reduce the transmembrane pressure increase by 18% when utilized alone, and by 49% when used in combination with citric acid. The combined treatment was more effective compared with the citric acid treatment alone, which reported ca. 30% transmembrane pressure reduction. Collectively, the findings demonstrated that bacteriophages can be used as a biocidal agent to mitigate undesirable P. aeruginosa-associated problems in seawater applications. PMID:29770130

Time course of pH change in plant epidermis using microscopic pH imaging system

NASA Astrophysics Data System (ADS)

Dan, Risako; Shimizu, Megumi; Kazama, Haruko; Sakaue, Hirotaka

2010-11-01

We established a microscopic pH imaging system to track the time course of pH change in plant epidermis in vivo. In the previous research, we have found out that anthocyanin containing cells have higher pH. However, it was not clear whether the anthocyanin increased the pH or anthocyanin was synthesized result from the higher pH. Therefore, we further investigated the relationship between anthocyanin and pH change. To track the time course of pH change in plant epidermis, we established a system using luminescent imaging technique. We used HPTS (8-Hydroxypyrene-1,3,6-Trisulfonate) as pH indicator and applied excitation ratio imaging method. Luminescent image was converted to a pH distribution by obtained in vitro calibration using known pH solution. Cellular level observation was enabled by merging microscopic color picture of the same region to the pH change image. The established system was applied to epidermal cells of red-tip leaf lettuce, Lactuca Sativa L. and the time course was tracked in the growth process. We would discuss about the relationship between anthocyanin and pH change in plant epidermis.

Vein Graft Preservation Solutions, Patency, and Outcomes After Coronary Artery Bypass Graft Surgery

PubMed Central

Harskamp, Ralf E.; Alexander, John H.; Schulte, Phillip J.; Brophy, Colleen M.; Mack, Michael J.; Peterson, Eric D.; Williams, Judson B.; Gibson, C. Michael; Califf, Robert M.; Kouchoukos, Nicholas T.; Harrington, Robert A.; Ferguson, T. Bruce; Lopes, Renato D.

2015-01-01

IMPORTANCE In vitro and animal model data suggest that intraoperative preservation solutions may influence endothelial function and vein graft failure (VGF) after coronary artery bypass graft (CABG) surgery. Clinical studies to validate these findings are lacking. OBJECTIVE To evaluate the effect of vein graft preservation solutions on VGF and clinical outcomes in patients undergoing CABG surgery. DESIGN, SETTING, AND PARTICIPANTS Data from the Project of Ex-Vivo Vein Graft Engineering via Transfection IV (PREVENT IV) study, a phase 3, multicenter, randomized, double-blind, placebo-controlled trial that enrolled 3014 patients at 107 US sites from August 1, 2002, through October 22, 2003, were used. Eligibility criteria for the trial included CABG surgery for coronary artery disease with at least 2 planned vein grafts. INTERVENTIONS Preservation of vein grafts in saline, blood, or buffered saline solutions. MAIN OUTCOMES AND MEASURES One-year angiographic VGF and 5-year rates of death, myocardial infarction, and subsequent revascularization. RESULTS Most patients had grafts preserved in saline (1339 [44.4%]), followed by blood (971 [32.2%]) and buffered saline (507 [16.8%]). Baseline characteristics were similar among groups. One-year VGF rates were much lower in the buffered saline group than in the saline group (patient-level odds ratio [OR], 0.59 [95% CI, 0.45-0.78; P < .001]; graft-level OR, 0.63 [95% CI, 0.49-0.79; P < .001]) or the blood group (patient-level OR, 0.62 [95% CI, 0.46-0.83; P = .001]; graft-level OR, 0.63 [95% CI, 0.48-0.81; P < .001]). Use of buffered saline solution also tended to be associated with a lower 5-year risk for death, myocardial infarction, or subsequent revascularization compared with saline (hazard ratio, 0.81 [95% CI, 0.64-1.02; P = .08]) and blood (0.81 [0.63-1.03; P = .09]) solutions. CONCLUSIONS AND RELEVANCE Patients undergoing CABG whose vein grafts were preserved in a buffered saline solution had lower VGF rates and trends

Effect of povidone-iodine addition on the corrosion behavior of cp-Ti in normal saline.

PubMed

Bhola, Rahul; Bhola, Shaily M; Mishra, Brajendra; Olson, David L

2010-05-01

The effect of various concentrations of povidone-iodine (PI) on the corrosion behavior of a commercially pure titanium alloy (Ti-1) has been investigated in normal saline solution to simulate the povidone-iodine addition in an oral environment. The open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization measurements have been used to characterize the electrochemical phenomena occurring on the alloy surface. The open circuit potential values for Ti-1 in various concentrations of PI shift considerably towards noble direction as compared to pure normal saline. In the potentiodynamic polarization curve for Ti-1 in various solutions, the cathodic current density has increased for all concentrations of PI and the anodic current density has decreased. Only the 0.1% PI concentration is able to inhibit corrosion of Ti-1 in normal saline and the other higher concentrations studied, accelerate corrosion. The EIS data for Ti-1 in normal saline and in various concentrations of PI follows a one time constant circuit, suggesting the formation of a single passive film on Ti-1 which is not altered by the addition of PI to normal saline.

The study of ikaite formation in sea ice

NASA Astrophysics Data System (ADS)

Hu, Y.; Nehrke, G.; Dieckmann, G.; Völker, C.; Wolf-Gladrow, D.

2012-04-01

Ikaite (CaCO3.6H2O) is a metastable mineral of calcium carbonate, which is usually found in environments characterized by low temperature (below 5° C), high pH, high alkalinity, high concentration of phosphate and organic matter. Although synthetic CaCO3.6H2O was already known from laboratory studies in 1865, ikaite was first observed in nature in 1963. Recently, Dieckmann et al. (2008, 2010) discovered this mineral in sea ice, which at the same time, was the first direct proof of CaCO3 precipitation in sea ice. However, little is known about the mechanism of ikaite formation in sea ice. Our study focuses on how physico-chemical processes in sea ice affect the formation of ikaite. Experiments were set up at pH ranging from 8.5 to 9.0, and salinity ranging from 0 to 105 at 0 ° C, in order to examine the effect of pH, salinity and also phosphate on the formation of ikaite. Preliminary results read: (1) Experiments show that ikaite can form at different pH levels (8.5~9.0). At high pH, the induction time (the time when the crystals start to precipitate) is shorter which means high pH favours the formation of ikaite. This might be expected given higher CO32- concentrations and thus higher saturation levels for ikaite with increasing pH. (2) The results of experiments with different salinities show that ikaite can form over wide range of salinities from 0 to 105 both in Artificial Sea Water (ASW) and NaCl solution in the presence of phosphate. In ASW, the induction time increases with salinity from S = 0 to S =105; while in NaCl solution, the induction time first increases with salinity and then decreases with the further increase of salinity. Salinity plays both positive and negative roles in the formation of ikaite. On the one hand, the increase in salinity will increase the fraction of CO32- in DIC. On the other hand, the increase in salinity means more ions are involved in the solution, which will reduce the activities of Ca2+ and CO32-by forming ion pairs with

Hemoglobin bioconjugates with surface-protected gold nanoparticles in aqueous media: The stability depends on solution pH and protein properties.

PubMed

Del Caño, Rafael; Mateus, Lucia; Sánchez-Obrero, Guadalupe; Sevilla, José Manuel; Madueño, Rafael; Blázquez, Manuel; Pineda, Teresa

2017-11-01

The identification of the factors that dictate the formation and physicochemical properties of protein-nanomaterial bioconjugates are important to understand their behavior in biological systems. The present work deals with the formation and characterization of bioconjugates made of the protein hemoglobin (Hb) and gold nanoparticles (AuNP) capped with three different molecular layers (citrate anions (c), 6-mercaptopurine (MP) and ω-mercaptoundecanoic acid (MUA)). The main focus is on the behavior of the bioconjugates in aqueous buffered solutions in a wide pH range. The stability of the bioconjugates have been studied by UV-visible spectroscopy by following the changes in the localized surface resonance plasmon band (LSRP), Dynamic light scattering (DLS) and zeta-potential pH titrations. It has been found that they are stable in neutral and alkaline solutions and, at pH lower than the protein isoelectric point, aggregation takes place. Although the surface chemical properties of the AuNPs confer different properties in respect to colloidal stability, once the bioconjugates are formed their properties are dictated by the Hb protein corona. The protein secondary structure, as analyzed by Attenuated total reflectance infrared (ATR-IR) spectroscopy, seems to be maintained under the conditions of colloidal stability but some small changes in protein conformation take place when the bioconjugates aggregate. These findings highlight the importance to keep the protein structure upon interaction with nanomaterials to drive the stability of the bioconjugates. Copyright © 2017 Elsevier Inc. All rights reserved.

Alleviation of the effects of saline-alkaline stress on maize seedlings by regulation of active oxygen metabolism by Trichoderma asperellum.

PubMed

Fu, Jian; Liu, Zhihua; Li, Zuotong; Wang, Yufeng; Yang, Kejun

2017-01-01

This study investigated the influence of Trichoderma asperellum on active oxygen production in maize seedlings under saline-alkaline stress conditions. Two maize cultivars were tested: 'Jiangyu 417' ('JY417'), which can tolerate saline-alkaline stress; and, 'Xianyu 335' ('XY335'), which is sensitive to saline-alkaline stress. The seedlings were grown on natural saline-alkaline soil (pH 9.30) in plastic pots. To each liter of saline-alkaline soil, 200 mL of T. asperellum spore suspension was applied; three fungal suspensions were used, namely, 1 × 103, 1 × 106, and 1 × 109 spores/L. A control with only the vehicle applied was also established, along with a second control in which untreated meadow soil (pH 8.23) was used. Root and leaf samples were collected when the seedlings had three heart-shaped leaves and the fourth was in the developmental phase. Physical and biochemical parameters related to oxidation resistance were assessed. The results indicated that the 'JY417' and 'XY335' seedlings showed different degrees of oxidative damage and differences in their antioxidant defense systems under saline-alkaline stress. As the spore density of the fungal suspension increased, the K+ and Ca2+ contents in the seedlings increased, but Na+ content decreased. Moreover, fungal treatment promoted the synthesis or accumulation of osmolytes, which enhanced the water absorbing capacity of the cells, increased antioxidant enzyme activities, enhanced the content of non-enzyme antioxidants, and reduced the accumulation of reactive oxygen species. Fungal treatment alleviated oxidative damage caused by the saline-alkaline stress in roots and leaves of the seedlings. The application of T. asperellum overcame the inhibitory effect of saline-alkaline soil stress on the growth of maize seedlings. In the present experiment, application with 1 × 109 spores/L gave the optimal results.

Self-assembly behavior of pH- and thermosensitive amphiphilic triblock copolymers in solution: experimental studies and self-consistent field theory simulations.

PubMed

Cai, Chunhua; Zhang, Liangshun; Lin, Jiaping; Wang, Liquan

2008-10-09

We investigated, both experimentally and theoretically, the self-assembly behaviors of pH- and thermosensitive poly(L-glutamic acid)- b-poly(propylene oxide)-b-poly(L-glutamic acid) (PLGA-b-PPO-b-PLGA) triblock copolymers in aqueous solution by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), circular dichroism (CD), and self-consistent field theory (SCFT) simulations. Vesicles were observed when the hydrophilic PLGA block length is shorter or the pH value of solution is lower. The vesicles were found to transform to spherical micelles when the PLGA block length increases or its conformation changes from helix to coil with increasing the pH value. In addition, increasing temperature gives rise to a decrease in the size of aggregates, which is related to the dehydration of the PPO segments at higher temperatures. The SCFT simulation results show that the vesicles transform to the spherical micelles with increasing the fraction or statistical length of A block in model ABA triblock copolymer, which corresponds to the increase in the PLGA length or its conformation change from helix to coil in experiments, respectively. The SCFT calculations also provide chain distribution information in the aggregates. On the basis of both experimental and SCFT results, the mechanism of the structure change of the PLGA- b-PPO- b-PLGA aggregates was proposed.

Chemical Speciation and Bond Lengths of Organic Solutes by Core-Level Spectroscopy: pH and Solvent Influence on p-Aminobenzoic Acid.

PubMed

Stevens, Joanna S; Gainar, Adrian; Suljoti, Edlira; Xiao, Jie; Golnak, Ronny; Aziz, Emad F; Schroeder, Sven L M

2015-05-04

Through X-ray absorption and emission spectroscopies, the chemical, electronic and structural properties of organic species in solution can be observed. Near-edge X-ray absorption fine structure (NEXAFS) and resonant inelastic X-ray scattering (RIXS) measurements at the nitrogen K-edge of para-aminobenzoic acid reveal both pH- and solvent-dependent variations in the ionisation potential (IP), 1s→π* resonances and HOMO-LUMO gap. These changes unequivocally identify the chemical species (neutral, cationic or anionic) present in solution. It is shown how this incisive chemical state sensitivity is further enhanced by the possibility of quantitative bond length determination, based on the analysis of chemical shifts in IPs and σ* shape resonances in the NEXAFS spectra. This provides experimental access to detecting even minor variations in the molecular structure of solutes in solution, thereby providing an avenue to examining computational predictions of solute properties and solute-solvent interactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Salinity controls on plant transpiration and soil water balance

NASA Astrophysics Data System (ADS)

Perri, S.; Molini, A.; Suweis, S. S.; Viola, F.; Entekhabi, D.

2017-12-01

Soil salinization and aridification represent a major threat for the food security and sustainable development of drylands. The two problems are deeply connected, and their interplay is expected to be further enhanced by climate change and projected population growth. Salt-affected land is currently estimated to cover around 1.1 Gha, and is particularly widespread in semi-arid to hyper-arid climates. Over 900 Mha of these saline/sodic soils are potentially available for crop or biomass production. Salt-tolerant plants have been recently proposed as valid solution to exploit or even remediate salinized soils. However the effects of salinity on evapotranspiration, soil water balance and the long-term salt mass balance in the soil, are still largely unexplored. In this contribution we analyze the feedback of evapotranspiration on soil salinization, with particular emphasis on the role of vegetation and plant salt-tolerance. The goal is to introduce a simple modeling framework able to shed some light on how (a) soil salinity controls plant transpiration, and (b) salinization itself is favored/impeded by different vegetation feedback. We introduce at this goal a spatially lumped stochastic model of soil moisture and salt mass dynamics averaged over the active soil depth, and accounting for the effect of salinity on evapotranspiration. Here, the limiting effect of salinity on ET is modeled through a simple plant response function depending on both salt concentration in the soil and plant salt-tolerance. The coupled soil moisture and salt mass balance is hence used to obtain the conditional steady-state probability density function (pdf) of soil moisture for given salt tolerance and salinization level, Our results show that salinity imposes a limit in the soil water balance and this limit depends on plant salt-tolerance mainly through the control of the leaching occurrence (tolerant plants exploit water more efficiently than the sensitive ones). We also analyzed the

Oscillating Adriatic temperature and salinity regimes mapped using the Self-Organizing Maps method

NASA Astrophysics Data System (ADS)

Matić, Frano; Kovač, Žarko; Vilibić, Ivica; Mihanović, Hrvoje; Morović, Mira; Grbec, Branka; Leder, Nenad; Džoić, Tomislav

2017-01-01

This paper aims to document salinity and temperature regimes in the middle and south Adriatic Sea by applying the Self-Organizing Maps (SOM) method to the available long-term temperature and salinity series. The data were collected on a seasonal basis between 1963 and 2011 in two dense water collecting depressions, Jabuka Pit and Southern Adriatic Pit, and over the Palagruža Sill. Seasonality was removed prior to the analyses. Salinity regimes have been found to oscillate rapidly between low-salinity and high-salinity SOM solutions, ascribed to the advection of Western and Eastern Mediterranean waters, respectively. Transient salinity regimes normally lasted less than a season, while temperature transient regimes lasted longer. Salinity regimes prolonged their duration after the major basin-wide event, the Eastern Mediterranean Transient, in the early 1990s. A qualitative relationship between high-salinity regimes and dense water formation and dynamics has been documented. The SOM-based analyses have a large capacity for classifying the oscillating ocean regimes in a basin, which, in the case of the Adriatic Sea, beside climate forcing, is an important driver of biogeochemical changes that impacts trophic relations, appearance and abundance of alien organisms, and fisheries, etc.

The formation and stability of saline minerals at the Martian surface

NASA Astrophysics Data System (ADS)

Tosca, Nicholas James, III

Evaporite minerals have been identified throughout the martian sedimentary record. Because evaporites can record detailed paleo-environmental information and often host fossil biosignatures on Earth, they are priority targets for future exploration. However, understanding processes that control the formation of these minerals on Mars requires an understanding of the behavior of Fe in highly concentrated evaporating fluids. In this study, a model is developed using the Pitzer ion interaction approach that accurately describes thermodynamic properties of the Fe2(SO4)3-H2SO4-H 2O system. Incorporating this model into a multicomponent thermodynamic database enables detailed study of evaporite mineral formation and stability on Mars. From geochemical modeling, the variation in evaporite mineralogy on Mars may be traced to volatile-anion input -- a variable intimately tied to pH. Using the "chemical divide" concept, evaporites at the martian surface can be used as sensitive probes of pH, atmospheric composition, and cation proportion in solution. Applying this approach to saline assemblages in Nakhlite meteorites and in Meridiani Planum sediments reveals two geochemical systems; each characterized by different pH and anion proportion. A complicating factor however is the concomitant oxidation of soluble Fe-bearing minerals. Such a process may have contributed to complex Fe mineralogy observed at Meridiani Planum through diagenesis. Fe-oxidation experiments at high ionic strength show a progression of mineral phases that begins with the formation of schwertmannite and subsequent ageing to jarosite and nano-crystalline goethite; a process strongly controlled by pH. Low water activity and small particle size drive the ageing of goethite to hematite which provides the final step of a mechanism that is consistent with the distribution of Fe-minerals at Meridiani Planum. These results show that the instability of Fe2+-sulfate minerals at the martian surface may lead to the

The use of physiological solutions or media in calcium phosphate synthesis and processing.

PubMed

Tas, A Cuneyt

2014-05-01

This review examined the literature to spot uses, if any, of physiological solutions/media for the in situ synthesis of calcium phosphates (CaP) under processing conditions (i.e. temperature, pH, concentration of inorganic ions present in media) mimicking those prevalent in the human hard tissue environments. There happens to be a variety of aqueous solutions or media developed for different purposes; sometimes they have been named as physiological saline, isotonic solution, cell culture solution, metastable CaP solution, supersaturated calcification solution, simulated body fluid or even dialysate solution (for dialysis patients). Most of the time such solutions were not used as the aqueous medium to perform the biomimetic synthesis of calcium phosphates, and their use was usually limited to the in vitro testing of synthetic biomaterials. This review illustrates that only a limited number of research studies used physiological solutions or media such as Earle's balanced salt solution, Bachra et al. solutions or Tris-buffered simulated body fluid solution containing 27mM HCO3(-) for synthesizing CaP, and these studies have consistently reported the formation of X-ray-amorphous CaP nanopowders instead of Ap-CaP or stoichiometric hydroxyapatite (HA, Ca10(PO4)6(OH)2) at 37°C and pH 7.4. By relying on the published articles, this review highlights the significance of the use of aqueous solutions containing 0.8-1.5 mMMg(2+), 22-27mM HCO3(-), 142-145mM Na(+), 5-5.8mM K(+), 103-133mM Cl(-), 1.8-3.75mM Ca(2+), and 0.8-1.67mM HPO4(2-), which essentially mimic the composition and the overall ionic strength of the human extracellular fluid (ECF), in forming the nanospheres of X-ray-amorphous CaP. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Effects of starvation on the transport of Escherichia coli K12 in saturated porous media are dependent on pH and ionic strength

NASA Astrophysics Data System (ADS)

Xu, S.; Walczak, J. J.; Wang, L.; Bardy, S. L.; Li, J.

2010-12-01

In this research, we investigate the effects of starvation on the transport of E. coli K12 in saturated porous media. Particularly, we examine the relationship between such effects and the pH and ionic strength of the electrolyte solutions that were used to suspend bacterial cells. E. coli K12 (ATCC 10798) cells were cultured using either Luria-Bertani Miller (LB-Miller) broth (10 g trypton, 5 g yeast extract and 10 g NaCl in 1 L of deionized water) or LB-Luria broth (10 g tryptone, 5 g yeast extract and 0.5 g NaCl in 1 L of deionized water). Both broths had similar pH (~7.1) but differed in ionic strength (LB-Miller: ~170 mM, LB-Luria: ~ 8 mM). The bacterial cells were then harvested and suspended using one of the following electrolyte solutions: phosphate buffered saline (PBS) (pH ~7.2; ionic strength ~170 mM), 168 mM NaCl (pH ~5.7), 5% of PBS (pH ~ 7.2; ionic strength ~ 8 mM) and 8 mM NaCl (pH ~ 5.7). Column transport experiments were performed at 0, 21 and 48 hours following cell harvesting to evaluate the change in cell mobility over time under “starvation” conditions. Our results showed that 1) starvation increased the mobility of E. coli K12 cells; 2) the most significant change in mobility occurred when bacterial cells were suspended in an electrolyte solution that had different pH and ionic strength (i.e., LB-Miller culture suspended in 8 mM NaCl and LB-Luria culture suspended in 168 mM Nacl); and 3) the change in cell mobility primarily occurred within the first 21 hours. The size of the bacterial cells was measured and the surface properties (e.g., zeta potential, hydrophobicity, cell-bound protein, LPS sugar content, outer membrane protein profiles) of the bacterial cells were characterized. We found that the measured cell surface properties could not fully explain the observed changes in cell mobility caused by starvation.

Acid Rain, pH & Acidity: A Common Misinterpretation.

ERIC Educational Resources Information Center

Clark, David B.; Thompson, Ronald E.

1989-01-01

Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

Effect of sodium hypochlorite and saline on cyclic fatigue resistance of WaveOne Gold and Reciproc reciprocating instruments.

PubMed

Elnaghy, A M; Elsaka, S E

2017-10-01

To compare the cyclic fatigue resistance of WaveOne Gold (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA) and Reciproc (VDW, Munich, Germany) reciprocating instruments during immersion in sodium hypochlorite (NaOCl) and saline solutions at body temperature. A total of 180 new WaveOne Gold primary size 25, .07 taper, and Reciproc size 25, .08 taper were randomly divided into three groups: group 1: no immersion (control, air); group 2: immersion in saline at 37 ± 1 °C; and group 3: immersion in 5% NaOCl at 37 ± 1 °C. The instruments were reciprocated in the test solution until fracture, and the number of cycles to failure was recorded. The data were analysed statistically using t-tests and one-way analysis of variance (anova) with the significance level set at P < 0.05. A Weibull analysis was performed on number of cycles to failure data. WaveOne Gold instruments had significantly greater number of cycles to failure than Reciproc instruments in all groups (P < 0.001). Fatigue resistance for both instruments tested in air was significantly higher than that in saline and NaOCl solutions (P < 0.001). For both instruments, there was no significant difference in the fatigue resistance between saline and NaOCl solutions (P > 0.05). The Weibull analysis showed that the predicted cycles of WaveOne Gold in air was 1027 cycles for 99% survival. However, Reciproc instruments tested in NaOCl solution had the lowest predicted cycles (613 cycles) among the groups. Immersion of WaveOne Gold and Reciproc reciprocating instruments in saline and NaOCl solutions decreased considerably their cyclic fatigue resistance. The fatigue resistance of WaveOne Gold instruments was higher than that of Reciproc instruments. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Soil solution interactions may limit Pb remediation using P amendments in an urban soil

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

Obrycki, John F.; Scheckel, Kirk G.; Basta, Nicholas T.

Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg -1 was amended in a laboratory study with bone meal and triple super phosphate (TSP) at 5:1 P:Pb molar ratios. Soil was acidified, neturalized and re-acidified to encourage Pb phosphate formation. PRSTM-probes were used to evaluate changes in soil solution chemistry. Soil acidification did not decrease in vitro bioaccessible (IVBA) Pb using either a pH 1.5, 0.4 M glycine solution or a pH 2.5 solution with organicmore » acids. PRSTM-probe data found soluble Pb increased 10-fold in acidic conditions compared to circumnetural pH conditions. In acidic conditions (p = 3-4), TSP treated soils increased detected P 10-fold over untreated soils. Bone meal application did not increase PRSTM-probe detected P, indicating there may have been insufficient P to react with Pb. X-ray absorption spectroscopy suggested a 10% increase in pyromorphite formation for the TSP treated soil only. Treatments increased soil electrical conductivity above 16 mS cm -1, potentially causing a new salinity hazard. This study used a novel approach by combining the human ingestion endpoint, PRSTM-probes, and X-ray absorption spectroscopy to evaluate treatment efficacy. PRSTM-probe data indicated potentially excess Ca relative to P across incubation steps that could have competed with Pb for soluble P. More research is needed to characterize soil solutions in Pb contaminated urban soils to identify where P treatments might be effective and when competing cations, such as Ca, Fe, and Zn may limit low rate P applications for treating Pb soils.« less

Soil solution interactions may limit Pb remediation using P amendments in an urban soil.

PubMed

Obrycki, John F; Scheckel, Kirk G; Basta, Nicholas T

2017-01-01

Lead (Pb) contaminated soils are a potential exposure hazard to the public. Amending soils with phosphorus (P) may reduce Pb soil hazards. Soil from Cleveland, OH containing 726 ± 14 mg Pb kg -1 was amended in a laboratory study with bone meal and triple super phosphate (TSP) at 5:1 P:Pb molar ratios. Soil was acidified, neturalized and re-acidified to encourage Pb phosphate formation. PRSTM-probes were used to evaluate changes in soil solution chemistry. Soil acidification did not decrease in vitro bioaccessible (IVBA) Pb using either a pH 1.5, 0.4 M glycine solution or a pH 2.5 solution with organic acids. PRSTM-probe data found soluble Pb increased 10-fold in acidic conditions compared to circumnetural pH conditions. In acidic conditions (p = 3-4), TSP treated soils increased detected P 10-fold over untreated soils. Bone meal application did not increase PRSTM-probe detected P, indicating there may have been insufficient P to react with Pb. X-ray absorption spectroscopy suggested a 10% increase in pyromorphite formation for the TSP treated soil only. Treatments increased soil electrical conductivity above 16 mS cm -1 , potentially causing a new salinity hazard. This study used a novel approach by combining the human ingestion endpoint, PRSTM-probes, and X-ray absorption spectroscopy to evaluate treatment efficacy. PRSTM-probe data indicated potentially excess Ca relative to P across incubation steps that could have competed with Pb for soluble P. More research is needed to characterize soil solutions in Pb contaminated urban soils to identify where P treatments might be effective and when competing cations, such as Ca, Fe, and Zn may limit low rate P applications for treating Pb soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ionically cross-linked poly(allylamine) as a stimulus-responsive underwater adhesive: ionic strength and pH effects.

PubMed

Lawrence, Patrick G; Lapitsky, Yakov

2015-02-03

Gel-like coacervates that adhere to both hydrophilic and hydrophobic substrates under water have recently been prepared by ionically cross-linking poly(allylamine) (PAH) with pyrophosphate (PPi) and tripolyphosphate (TPP). Among the many advantages of these underwater adhesives (which include their simple preparation and low cost) is their ability to dissolve on demand when exposed to high or low pH. To further analyze their stimulus-responsive properties, we have investigated the pH and ionic strength effects on the formation, rheology and adhesion of PAH/PPi and PAH/TPP complexes. The ionic cross-linker concentrations needed to form these adhesives decreased with increasing pH and ionic strength (although the complexes ceased to form when the parent solution pH exceeded ca. 8.5; i.e., the effective pKa of PAH). Once formed, their ionic cross-links were most stable (as inferred from their relaxation times) at near-neutral or slightly alkaline pH values (of roughly 6.5-9) and at low ionic strengths. The decrease in ionic cross-link stability within complexes prepared at other pH values and at elevated (150-300 mM) NaCl concentrations diminished both the strength and longevity of adhesion (although, under most conditions tested, the short-term tensile adhesion strengths remained above 10(5) Pa). Additionally, the sensitivity of PAH/PPi and PAH/TPP complexes to ionic strength was demonstrated as a potential route to injectable adhesive design (where spontaneous adhesive formation was triggered via injection of low-viscosity, colloidal PAH/TPP dispersions into phosphate buffered saline). Thus, while the sensitivity of ionically cross-linked PAH networks to pH and ionic strength can weaken their adhesion, it can also impart them with additional functionality, such as minimally invasive, injectable delivery, and ability to form and dissolve their bonds on demand.

Determining pH of strip-mine spoils

Treesearch

W. A. Berg

1969-01-01

Results with the LaMotte-Morgan method for determining soil pH-or the solution modification of this method-usually agreed fairly well with the results from using a pH meter, the recognized standard. Results obtained with the Soiltex and Hellige-Truog methods often deviated somewhat from the pH meter readings; and the Hydrion papers and the Kelway pH tester often gave...

Physiological and Biochemical Responses of Lavandula angustifolia to Salinity Under Mineral Foliar Application

PubMed Central

Chrysargyris, Antonios; Michailidi, Evgenia; Tzortzakis, Nikos

2018-01-01

Saline water has been proposed as a solution to partially cover plant water demands due to scarcity of irrigation water in hot arid areas. Lavender (Lavandula angustifolia Mill.) plants were grown hydroponically under salinity (0–25–50–100 mM NaCl). The overcome of salinity stress was examined by K, Zn, and Si foliar application for the plant physiological and biochemical characteristics. The present study indicated that high (100 mM NaCl) salinity decreased plant growth, content of phenolics and antioxidant status and essential oil (EO) yield, while low-moderate salinity levels maintained the volatile oil profile in lavender. The integrated foliar application of K and Zn lighten the presumable detrimental effects of salinity in terms of fresh biomass, antioxidant capacity, and EO yield. Moderate salinity stress along with balanced concentration of K though foliar application changed the primary metabolites pathways in favor of major volatile oil constituents biosynthesis and therefore lavender plant has the potential for cultivation under prevalent semi-saline conditions. Zn and Si application, had lesser effects on the content of EO constituents, even though altered salinity induced changings. Our results have demonstrated that lavender growth/development and EO production may be affected by saline levels, whereas mechanisms for alteration of induced stress are of great significance considering the importance of the oil composition, as well. PMID:29731759

Physiological and Biochemical Responses of Lavandula angustifolia to Salinity Under Mineral Foliar Application.

PubMed

Chrysargyris, Antonios; Michailidi, Evgenia; Tzortzakis, Nikos

2018-01-01

Saline water has been proposed as a solution to partially cover plant water demands due to scarcity of irrigation water in hot arid areas. Lavender ( Lavandula angustifolia Mill.) plants were grown hydroponically under salinity (0-25-50-100 mM NaCl). The overcome of salinity stress was examined by K, Zn, and Si foliar application for the plant physiological and biochemical characteristics. The present study indicated that high (100 mM NaCl) salinity decreased plant growth, content of phenolics and antioxidant status and essential oil (EO) yield, while low-moderate salinity levels maintained the volatile oil profile in lavender. The integrated foliar application of K and Zn lighten the presumable detrimental effects of salinity in terms of fresh biomass, antioxidant capacity, and EO yield. Moderate salinity stress along with balanced concentration of K though foliar application changed the primary metabolites pathways in favor of major volatile oil constituents biosynthesis and therefore lavender plant has the potential for cultivation under prevalent semi-saline conditions. Zn and Si application, had lesser effects on the content of EO constituents, even though altered salinity induced changings. Our results have demonstrated that lavender growth/development and EO production may be affected by saline levels, whereas mechanisms for alteration of induced stress are of great significance considering the importance of the oil composition, as well.

Changes in soil solution Zn and pH and uptake of Zn by arbuscular mycorrhizal red clover in Zn-contaminated soil.

PubMed

Li, X; Christie, P

2001-01-01

Red clover plants inoculated with Glomus mosseae were grown in a sterile pasture soil containing 50 mg Zn kg(-1) in 'Plexiglas' (acrylic) containers with nylon net partitions (30 microm mesh) designed to separate the soil into a central root zone and two outer zones for hyphal growth with no root penetration. Two porous plastic soil moisture samplers were installed in each pot, one in the root compartment and the other in one of the hyphal compartments. The soil in the outer compartments was amended with one of the four application rates of Zn (as ZnSO4) ranging from 0 to 1000 mg kg(-1). Non-mycorrhizal controls were included, and there were five replicates of each treatment in a randomised block in a glasshouse. Uninoculated plants received supplementary P to avoid yield limitation due to low soil P status. Plants grew in the central compartment for nine weeks. Soil moisture samples were collected 4, 24 and 62 days after sowing to monitor changes in the Zn concentration and pH of the soil solution. At harvest, the mean mycorrhizal infection rate of inoculated plants ranged from 29% to 34% of total root length and was little affected by Zn application. Root and shoot yields were not affected by mycorrhizal infection. Plant Zn concentration and uptake were lower in mycorrhizal plants than non-mycorrhizal controls, and this effect was more pronounced with increasing Zn application rate to the soil. Soil solution Zn concentrations were lower and pH values were higher in mycorrhizal treatments than non-mycorrhizal controls and the mycorrhiza effect was more pronounced at higher Zn application rates. The protective effect of mycorrhiza against plant Zn uptake may have been associated with changes in Zn solubility mediated by changes in the soil solution pH, or by immobilisation of Zn in the extraradical mycelium.

Electrochemical Induced Calcium Phosphate Precipitation: Importance of Local pH

PubMed Central

2017-01-01

Phosphorus (P) is an essential nutrient for living organisms and cannot be replaced or substituted. In this paper, we present a simple yet efficient membrane free electrochemical system for P removal and recovery as calcium phosphate (CaP). This method relies on in situ formation of hydroxide ions by electro mediated water reduction at a titanium cathode surface. The in situ raised pH at the cathode provides a local environment where CaP will become highly supersaturated. Therefore, homogeneous and heterogeneous nucleation of CaP occurs near and at the cathode surface. Because of the local high pH, the P removal behavior is not sensitive to bulk solution pH and therefore, efficient P removal was observed in three studied bulk solutions with pH of 4.0 (56.1%), 8.2 (57.4%), and 10.0 (48.4%) after 24 h of reaction time. While P removal efficiencies are not generally affected by bulk solution pH, the chemical-physical properties of CaP solids collected on the cathode are still related to bulk solution pH, as confirmed by structure characterizations. High initial solution pH promotes the formation of more crystalline products with relatively high Ca/P molar ratio. The Ca/P molar ratio increases from 1.30 (pH 4.0) to 1.38 (pH 8.2) and further increases to 1.55 (pH 10.0). The formation of CaP precipitates was a typical crystallization process, with an amorphous phase formed at the initial stage which then transforms to the most stable crystal phase, hydroxyapatite, which is inferred from the increased Ca/P molar ratio from 1.38 (day 1) to the theoretical 1.76 (day 11) and by the formation of needle-like crystals. Finally, we demonstrated the efficiency of this system for real wastewater. This, together with the fact that the electrochemical method can work at low bulk pH, without dosing chemicals and a need for a separation process, highlights the potential application of the electrochemical method for P removal and recovery. PMID:28872838

Technetium recovery from high alkaline solution

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

Nash, Charles A.

2016-07-12

Disclosed are methods for recovering technetium from a highly alkaline solution. The highly alkaline solution can be a liquid waste solution from a nuclear waste processing system. Methods can include combining the solution with a reductant capable of reducing technetium at the high pH of the solution and adding to or forming in the solution an adsorbent capable of adsorbing the precipitated technetium at the high pH of the solution.

Postprocedural pain in shoulder arthrography: differences between using preservative-free normal saline and normal saline with benzyl alcohol as an intraarticular contrast diluent.

PubMed

Storey, Troy F; Gilbride, George; Clifford, Kelly

2014-11-01

The purpose of this study was to prospectively evaluate the effect of benzyl alcohol, a common preservative in normal saline, on postprocedural pain after intraarticular injection for direct shoulder MR arthrography. From April 2011 through January 2013, 138 patients underwent direct shoulder MR arthrography. Using the Wong-Baker Faces Pain Scale, patients were asked to report their shoulder pain level immediately before and immediately after the procedure and then were contacted by telephone 6, 24, and 48 hours after the procedure. Fourteen patients did not receive the prescribed amount of contrast agent for diagnostic reasons or did not complete follow-up. Sixty-two patients received an intraarticular solution including preservative-free normal saline (control group) and 62 patients received an intraarticular solution including normal saline with 0.9% benzyl alcohol as a contrast diluent (test group). Patients were randomized as to which intraarticular diluent they received. Fluoroscopic and MR images were reviewed for extracapsular contrast agent administration or extravasation, full-thickness rotator cuff tears, and adhesive capsulitis. The effect of preservative versus control on pain level was estimated with multiple regression, which included time after procedure as the covariate and accounted for repeated measures over patients. Pain scale scores were significantly (p = 0.0382) higher (0.79 units; 95% CI, 0.034-1.154) with benzyl alcohol preservative compared with control (saline). In both study arms, the pain scale scores decreased slightly after the procedure, increased by roughly 1 unit over baseline for the test group and 0.3 unit over baseline for the control group by 6 hours after the procedure, were 0.50 unit over baseline for the test group and 0.12 unit over baseline for the control group at 24 hours, then fell to be slightly greater than baseline at 48 hours with benzyl alcohol and slightly less than baseline without benzyl alcohol. These trends

Analysis of Factors Influencing Soil Salinity, Acidity, and Arsenic Concentration in a Polder in Southwest Bangladesh

NASA Astrophysics Data System (ADS)

Ayers, J. C.; Patton, B.; Fry, D. C.; Goodbred, S. L., Jr.

2017-12-01

Soil samples were collected on Polder 32 in the coastal zone of SW Bangladesh in wet (October) and dry (May) seasons from 2013-2017 and analyzed to characterize the problems of soil salinization and arsenic contamination and identify their causes. Soils are entisols formed from recently deposited, predominantly silt-sized sediments with low carbon concentrations typical of the local mangrove forests. Soluble (DI extract) arsenic concentrations were below the Government of Bangladesh limit of 50 ppb for drinking water. Soil acidity and extract arsenic concentrations exhibit spatial variation but no consistent trends. In October soil extract As is higher and S and pH are lower than in May. These observations suggest that wet season rainwater oxidizes pyrite, reducing soil S and releasing H+, causing pH to decrease. Released iron is oxidized to form Hydrous Ferric Oxyhydroxides (HFOs), which sorb As and increase extractable As in wet season soils. Changes in pH are small due to pH buffering by soil carbonates. Soil and rice paddy water salinities are consistently higher in May than October, reaching levels in May that reduce rice yields. Rice grown in paddies should be unaffected by salt concentrations in the wet season, while arsenic concentrations in soil may be high enough to cause unsafe As levels in produced rice.

Episodic Salinization of Urban Rivers: Potential Impacts on Carbon, Cation, and Nutrient Fluxes

NASA Astrophysics Data System (ADS)

Haq, S.; Kaushal, S.

2017-12-01

Human dominated watersheds are subjected to an array of salt inputs (e.g. road salts), and in urban areas, infrastructure and impervious surfaces quickly drain applied road salts into the river channel. As a result, many streams experience episodic salinization over the course of hours to days following a snow event (e.g. road salt pulse), and long-term salinization over the course of seasons to decades. Salinization of streams can release contaminants (e.g. heavy metals), reduce biodiversity, and degrade drinking water quality. We investigated the water quality effects of episodic salinization in urban streams. Sediment and streamwater were incubated from twelve sites in the Baltimore-Washington Metropolitan Area under a range of sodium chloride treatments in a lab environment to mimic a vertical stream column with a sediment-water interface undergoing episodic salinization, and to characterize relationships between experimental salinization and nutrient/cation fluxes. Eight sites (Baltimore) exhibit a land use gradient and are routinely monitored within the Baltimore Ecosystem Study LTER project, and four sites (Washington DC) are suburban and offer a contrasting lithology and physiographic province. Our research suggests that salinization can mobilize total dissolved nitrogen, soluble reactive phosphorous, and base cations; potentially due to coupled biotic-abiotic processes, such as ion exchange, rapid nitrification, pH changes, and chloride-organic matter dispersal. The impact of salinization on dissolved inorganic and organic carbon varied between sites, potentially due to sediment composition, organic matter content, and ambient water quality. We contrasted the experimental results with measurements of salinization (specific conductance) and nutrients (nitrate) from real-time sensors operated by the US Geological Survey that encompass the same watersheds as our experimental sites. Sensor data was analyzed to provide insight on the timescales of salinity

Searching for Clues to the Processes and Conditions of Past Martian Environments: The Roles of Episodic Solutions, Analog Sites and Fe-O(-H) Phases

NASA Astrophysics Data System (ADS)

King, P. L.; De Deckker, P.

2012-12-01

On Mars, limited solutions (water/brine) were likely present episodically. Gradients in solution abundance may have caused salt precipitation and re-solution, brine reflux, pH gradients, and cycling of anions and cations; we provide an example of such processes in a playa lake. We propose that on Mars, the limited, episodic solutions, pH and abundant Fe-O(-H) phases are significant factors in salt precipitation and in promoting adsorption/desorption of anions and cations. FACTORS LEADING TO EPISODIC SOLUTIONS: Episodic movement of solutions may be driven by punctuated processes that 1) remove surface materials (e.g., impact and sedimentary mass wasting and deflation); 2) add surface materials (e.g., impact, volcanic and sedimentary processes); and 3) increase temperature and/or decrease atmospheric pressure (e.g., seasons, diurnal cycles, variation in obliquity). Removal and addition of surface materials results in topographic gradients that change pressure gradients of any potential groundwater, films, or buried ground ice. For example, episodic fluid flow and salt precipitation/re-solution may occur at topographic discontinuities like craters/basins, channel walls, mounds and dunes. Such areas provide the opportunity to sample multiple fluid sources (with different pH, Eh and total dissolved solids, TDS) and they may be the foci of subsurface solution flow and surface transport. EARTH ANALOG: Interplay of the three processes above is seen in Lake Tyrrell (playa), western Victoria, Australia (McCumber, P, 1991 http://vro.dpi.vic.gov.au). During wetter periods, springs from the regional groundwater (low pH, oxidized, mod-high TDS) mix with lake waters and saline 'reflux' brines (mod. pH, reduced, high TDS) at the lake edge at the base of higher ground. The Br/Cl of the reflux brines indicates mineral re-solution. Gypsum and Fe-O(-H) phases precipitate near the lake edge. During hot, dry climate episodes the lake precipitates gypsum and carbonate, efflorescent salts

Biodegradation of 3,5-dimethyl-2,4-dichlorophenol in saline wastewater by newly isolated Penicillium sp. yz11-22N2.

PubMed

Yan, Zhou; He, Huijun; Yang, Chunping; Zeng, Guangming; Luo, Le; Jiao, Panpan; Li, Huiru; Lu, Li

2017-07-01

In this study, the performance of 3,5-dimethyl-2,4-dichlorophenol (DCMX) degradation by a screened strain was investigated. 18S rDNA and the neighbor-joining method were used for identification of the isolated strain. The results of phylogenetic analysis and scanning electron micrographs showed that the most probable identity of the screened strain should be Penicillium sp. Growth characteristics of Penicillium sp. and degradation processes of DCMX were examined. Fourier transform infrared spectroscopy of the inoculated DCMX solution was recorded, which supported the capacity of DCMX degradation by the screened Penicillium sp. Under different salinity conditions, the highest growth rate and removal efficiency for DCMX were obtained at pH6.0. The removal efficiency decreased from 100% to 66% when the DCMX concentration increased from 5 to 60mg/L, respectively. Using a Box-Behnken design, the maximum DCMX removal efficiency was determined to be 98.4%. With acclimation to salinity, higher removal efficiency could be achieved. The results demonstrate that the screened Penicillium sp. has the capability for degradation of DCMX. Copyright © 2017. Published by Elsevier B.V.

Analytical steady-state solutions for water-limited cropping systems using saline irrigation water

USDA-ARS?s Scientific Manuscript database

Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems mod...

Metal/Metal Oxide Differential Electrode pH Sensors

NASA Technical Reports Server (NTRS)

West, William; Buehler, Martin; Keymeulen, Didier

2007-01-01

Solid-state electrochemical sensors for measuring the degrees of acidity or alkalinity (in terms of pH values) of liquid solutions are being developed. These sensors are intended to supplant older electrochemical pH sensors that include glass electrode structures and reference solutions. The older sensors are fragile and subject to drift. The present developmental solid-state sensors are more rugged and are expected to be usable in harsh environments. The present sensors are based on a differential-electrode measurement principle. Each sensor includes two electrodes, made of different materials, in equilibrium with the solution of interest.

Plant aquaporins: new perspectives on water and nutrient uptake in saline environment.

PubMed

del Martínez-Ballesta, M C; Silva, C; López-Berenguer, C; Cabañero, F J; Carvajal, M

2006-09-01

The mechanisms of salt stress and tolerance have been targets for genetic engineering, focusing on ion transport and compartmentation, synthesis of compatible solutes (osmolytes and osmoprotectants) and oxidative protection. In this review, we consider the integrated response to salinity with respect to water uptake, involving aquaporin functionality. Therefore, we have concentrated on how salinity can be alleviated, in part, if a perfect knowledge of water uptake and transport for each particular crop and set of conditions is available.

Thermal degradation of (6R,S)-5,10-methenyltetrahydrofolate in aqueous solution at pH 8

NASA Astrophysics Data System (ADS)

Tyagi, A.; Penzkofer, A.; Batschauer, A.; Wolf, E.

2009-03-01

The degradation of the folate (6R,S)-5,10-methenyltetrahydrofolate chloride (MTHF-Cl) in aqueous solution at pH 8 at room temperature is studied by absorption spectra measurements. Samples with and without the reducing agent β-mercaptoethanol (β-ME) both under aerobic and anaerobic conditions are investigated. MTHF-Cl hydrolyses to (6R,S)-10-formyltetrahydrofolate (10-HCO-H4folate) in all four cases. 10-HCO-H4folate oxidizes to 10-formyldihydrofolate (10-HCO-H2folate) under aerobic conditions in the absence of β-ME. The degradation dynamics is analysed theoretically and conversion rate constants of hydrolysis and oxidation are determined.

Chemical Speciation and Bond Lengths of Organic Solutes by Core-Level Spectroscopy: pH and Solvent Influence on p -Aminobenzoic Acid

DOE PAGES

Stevens, Joanna S.; Gainar, Adrian; Suljoti, Edlira; ...

2015-03-18

Through X-ray absorption and emission spectroscopies, the chemical, electronic and structural properties of organic species in solution can be observed. Near-edge X-ray absorption fine structure (NEXAFS) and resonant inelastic X-ray scattering (RIXS) measurements at the nitrogen K-edge of para-aminobenzoic acid reveal both pH- and solvent-dependent variations in the ionisation potential (IP), 1s→π* resonances and HOMO–LUMO gap. These changes unequivocally identify the chemical species (neutral, cationic or anionic) present in solution. It is shown how this incisive chemical state sensitivity is further enhanced by the possibility of quantitative bond length determination, based on the analysis of chemical shifts in IPs andmore » σ* shape resonances in the NEXAFS spectra. Finally, this provides experimental access to detecting even minor variations in the molecular structure of solutes in solution, thereby providing an avenue to examining computational predictions of solute properties and solute–solvent interactions.« less

An All-Solid-State pH Sensor Employing Fluorine-Terminated Polycrystalline Boron-Doped Diamond as a pH-Insensitive Solution-Gate Field-Effect Transistor.

PubMed

Shintani, Yukihiro; Kobayashi, Mikinori; Kawarada, Hiroshi

2017-05-05

A fluorine-terminated polycrystalline boron-doped diamond surface is successfully employed as a pH-insensitive SGFET (solution-gate field-effect transistor) for an all-solid-state pH sensor. The fluorinated polycrystalline boron-doped diamond (BDD) channel possesses a pH-insensitivity of less than 3mV/pH compared with a pH-sensitive oxygenated channel. With differential FET (field-effect transistor) sensing, a sensitivity of 27 mv/pH was obtained in the pH range of 2-10; therefore, it demonstrated excellent performance for an all-solid-state pH sensor with a pH-sensitive oxygen-terminated polycrystalline BDD SGFET and a platinum quasi-reference electrode, respectively.

The influence of pH on biotite dissolution and alteration kinetics at low temperature

USGS Publications Warehouse

Acker, James G.; Bricker, O.P.

1992-01-01

Biotite dissolution rates in acidic solutions were determined in fluidized-bed reactors and flowthrough columns. Biotite dissolution rates increased inversely as a linear function of pH in the pH range 3-7, where the rate order n = -0.34. Biotite dissolved incongruently over this pH range, with preferential release of magnesium and iron from the octahedral layer. Release of tetrahedral silicon was much greater at pH 3 than at higher pH. Iron release was significantly enhanced by low pH conditions. Solution compositions from a continuous exposure flow-through column of biotite indicated biotite dissolves incongruently at pH 4, consistent with alteration to a vermiculite-type product. Solution compositions from a second intermittent-flow column exhibited elevated cation release rates upon the initiation of each exposure to solution. The presence of strong oxidizing agents, the mineral surface area, and sample preparation methodology also influenced the dissolution or alteration kinetics of biotite. ?? 1992.

Salt exclusion and mycorrhizal symbiosis increase tolerance to NaCl and CaCl2 salinity in ‘Siam Queen’ basil

USDA-ARS?s Scientific Manuscript database

A study was conducted to evaluate the effects of salinity on growth and nutrient uptake in basil (Ocimum basilicum L.). Plants were fertilized with a complete nutrient solution and exposed to no, low, or moderate levels of salinity from NaCl or CaCl2. Plants in the control and moderate salinity tre...

Stochastic modeling of soil salinity

NASA Astrophysics Data System (ADS)

Suweis, S.; Porporato, A. M.; Daly, E.; van der Zee, S.; Maritan, A.; Rinaldo, A.

2010-12-01

A minimalist stochastic model of primary soil salinity is proposed, in which the rate of soil salinization is determined by the balance between dry and wet salt deposition and the intermittent leaching events caused by rainfall events. The equations for the probability density functions of salt mass and concentration are found by reducing the coupled soil moisture and salt mass balance equations to a single stochastic differential equation (generalized Langevin equation) driven by multiplicative Poisson noise. Generalized Langevin equations with multiplicative white Poisson noise pose the usual Ito (I) or Stratonovich (S) prescription dilemma. Different interpretations lead to different results and then choosing between the I and S prescriptions is crucial to describe correctly the dynamics of the model systems. We show how this choice can be determined by physical information about the timescales involved in the process. We also show that when the multiplicative noise is at most linear in the random variable one prescription can be made equivalent to the other by a suitable transformation in the jump probability distribution. We then apply these results to the generalized Langevin equation that drives the salt mass dynamics. The stationary analytical solutions for the probability density functions of salt mass and concentration provide insight on the interplay of the main soil, plant and climate parameters responsible for long term soil salinization. In particular, they show the existence of two distinct regimes, one where the mean salt mass remains nearly constant (or decreases) with increasing rainfall frequency, and another where mean salt content increases markedly with increasing rainfall frequency. As a result, relatively small reductions of rainfall in drier climates may entail dramatic shifts in longterm soil salinization trends, with significant consequences, e.g. for climate change impacts on rain fed agriculture.

Effect of pH on Semiconducting Property of Passive Film Formed on Ultra-High-Strength Corrosion-Resistant Steel in Sulfuric Acid Solution

NASA Astrophysics Data System (ADS)

Sun, Min; Xiao, Kui; Dong, Chaofang; Li, Xiaogang; Zhong, Ping

2013-10-01

Because Cr9Ni5MoCo14 is a new ultra-high-strength corrosion-resistant steel, it is important to study its corrosion behavior in sulfuric acid solution, which is used to simulate the aggressive environment. The effect of pH on the electrochemical and semiconducting properties of passive films formed on ultra-high-strength corrosion-resistant steel in sulfuric acid solution was investigated by means of the potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and X-ray photoelectron spectroscopy (XPS). The results indicated that Cr9Ni5MoCo14 steel showed a passive state in acid solutions. The corrosion behavior of this Cr9Ni5MoCo14 alloy was influenced by the passive film formed on the surface, including thickness, stability, and partitioning of elements of the passive film. The passive current density decreases with increasing pH, and the corrosion resistance was enhanced by the increasing thickness and depletion of the defects within the passive film. Moreover, an enrichment of chromium (primarily the oxides of Cr) and depletion of iron in the passive film led to improved corrosion resistance. These results can provide a theoretical basis for use of this alloy and further development of ultra-high-strength corrosion-resistant steel in today's society.

Compatibility and stability of tramadol and dexamethasone in solution and its use in terminally ill patients.

PubMed

Negro, S; Salama, A; Sánchez, Y; Azuara, M L; Barcia, E

2007-10-01

Delivery of drug admixtures by continuous subcutaneous infusion is common practice in palliative medicine, but analytical confirmation of their compatibility and stability is not always available. To study the compatibility and stability of tramadol hydrochloride and dexamethasone sodium phosphate combined in solution and to report on its use in terminally ill patients. Twelve different solutions containing tramadol hydrochloride (8.33-33.33 mg/mL) and dexamethasone sodium phosphate (0.33-3.33 mg/mL) were prepared in saline and stored in polypropylene syringes for 5 days (25 degrees C). Analysis was performed on days 1, 3 and 5 days with simultaneous determination by HPLC. pH was measured at 0 and 5 days. Clinical performance was assessed retrospectively in six terminal-ill oncology patients. Maximum losses of 7% and 6% were observed for tramadol and dexamethasone. Pain was completely controlled in four patients. Local tolerance resulted in haematoma in three patients, which resolved by switching to a butterfly insertion site. Tramadol hydrochloride (100-400 mg/day) and dexamethasone sodium phosphate (4-40 mg/day) are stable for at least 5 days when combined in saline and stored at 25 degrees C. These results are only valid for the type of syringes and the specific commercial preparations tested.

Use of mixed solid waste as a soil amendment for saline-sodic soil remediation and oat seedling growth improvement.

PubMed

Fan, Yuan; Ge, Tian; Zheng, Yanli; Li, Hua; Cheng, Fangqin

2016-11-01

Soil salinization has become a worldwide problem that imposes restrictions on crop production and food quality. This study utilizes a soil column experiment to address the potential of using mixed solid waste (vinegar residue, fly ash, and sewage sludge) as soil amendment to ameliorate saline-sodic soil and enhance crop growth. Mixed solid waste with vinegar residue content ranging from 60-90 %, sewage sludge of 8.7-30 %, and fly ash of 1.3-10 % was added to saline-sodic soil (electrical conductivity (EC 1:5 ) = 1.83 dS m -1 , sodium adsorption ratio (SAR 1:5 ) = 129.3 (mmol c L -1 ) 1/2 , pH = 9.73) at rates of 0 (control), 130, 260, and 650 kg ha -1 . Results showed that the application of waste amendment significantly reduced SAR, while increasing soil soluble K + , Ca 2+ , and Mg 2+ , at a dose of 650 kg ha -1 . The wet stability of macro-aggregates (>1 mm) was improved 90.7-133.7 % when the application rate of amendment was greater than 260 kg ha -1 . The application of this amendment significantly reduced soil pH. Germination rates and plant heights of oats were improved with the increasing rate of application. There was a positive correlation between the percentage of vinegar residue and the K/Na ratio in the soil solutions and roots. These findings suggest that applying a mixed waste amendment (vinegar residue, fly ash, and sewage sludge) could be a cost-effective method for the reclamation of saline-sodic soil and the improvement of the growth of salt-tolerant plants.

Microbial fuel cells in saline and hypersaline environments: Advancements, challenges and future perspectives.

PubMed

Grattieri, Matteo; Minteer, Shelley D

2018-04-01

This review is aimed to report the possibility to utilize microbial fuel cells for the treatment of saline and hypersaline solutions. An introduction to the issues related with the biological treatment of saline and hypersaline wastewater is reported, discussing the limitation that characterizes classical aerobic and anaerobic digestions. The microbial fuel cell (MFC) technology, and the possibility to be applied in the presence of high salinity, is discussed before reviewing the most recent advancements in the development of MFCs operating in saline and hypersaline conditions, with their different and interesting applications. Specifically, the research performed in the last 5years will be the main focus of this review. Finally, the future perspectives for this technology, together with the most urgent research needs, are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of temperature, light and salinity on seed germination and radicle growth of the geographically widespread halophyte shrub Halocnemum strobilaceum.

PubMed

Qu, Xiao-Xia; Huang, Zhen-Ying; Baskin, Jerry M; Baskin, Carol C

2008-01-01

The small leafy succulent shrub Halocnemum strobilaceum occurs in saline habitats from northern Africa and Mediterranean Europe to western Asia, and it is a dominant species in salt deserts such as those of north-west China. The effects of temperature, light/darkness and NaCl salinity were tested on seed germination, and the effects of salinity were tested on seed germination recovery, radicle growth and radicle elongation recovery, using seeds from north-west China; the results were compared with those previously reported on this species from 'salt steppes' in the Mediterranean region of Spain. Seed germination was tested over a range of temperatures in light and in darkness and over a range of salinities at 25 degrees C in the light. Seeds that did not germinate in the NaCl solutions were tested for germination in deionized water. Seeds from which radicles had barely emerged in deionized water were transferred to NaCl solutions for 10 d and then back to deionized water for 10 d to test for radicle growth and recovery. Seeds germinated to higher percentages in light than in darkness and at high than at low temperatures. Germination percentages decreased with an increase in salinity from 0.1 to 0.75 M NaCl. Seeds that did not germinate in NaCl solutions did so after transfer to deionized water. Radicle elongation was increased by low salinity, and then it decreased with an increase in salinity, being completely inhibited by > or = 2.0 M NaCl. Elongation of radicles from salt solutions < 3.0 M resumed after seedlings were transferred to deionized water. The seed and early seedling growth stages of the life cycle of H. strobilaceum are very salt tolerant, and their physiological responses differ somewhat between the Mediterranean 'salt steppe' of Spain and the inland cold salt desert of north-west China.

Conformal self-assembled thin films for optical pH sensors

NASA Astrophysics Data System (ADS)

Topasna, Daniela M.; Topasna, Gregory A.; Liu, Minghanbo; Tseng, Ching-Hung

2016-04-01

Simple, reliable, lightweight, and inexpensive thin films based sensors are still in intense development and high demand in many applications such as biomedical, industrial, environmental, military, and consumer products. One important class of sensors is the optical pH sensor. In addition, conformal thin film based sensors extend the range of application for pH optical sensors. We present the results on the fabrication and characterization of optical pH sensing coatings made through ionic self-assembled technique. These thin films are based on the combination of a polyelectrolyte and water-soluble organic dye molecule Direct Yellow 4. A series of films was fabricated and characterized in order to determine the optimized parameters of the polymer and of the organic dye solutions. The optical pH responses of these films were also studied. The transparent films were immersed in solutions at various temperature and pH values. The films are stable when immersed in solutions with pH below 9.0 and temperatures below 90 °C and they maintain their performance after longer immersion times. We also demonstrate the functionality of these coatings as conformal films.

Stability and tribological performances of fluid phospholipid bilayers: effect of buffer and ions.

PubMed

Dekkiche, F; Corneci, M C; Trunfio-Sfarghiu, A-M; Munteanu, B; Berthier, Y; Kaabar, W; Rieu, J-P

2010-10-15

We have investigated the mechanical and tribological properties of supported Dioleoyl phosphatidylcholine (DOPC) bilayers in different solutions: ultrapure water (pH 5.5), saline solution (150 mM NaCl, pH 5.8), Tris buffer (pH 7.2) and Tris saline buffer (150 mM NaCl, pH 7.2). Friction forces are measured using a homemade biotribometer. Lipid bilayer degradation is controlled in situ during friction tests using fluorescence microscopy. Mechanical resistance to indentation is measured by force spectroscopy with an atomic force microscope. This study confirms that mechanical stability under shear or normal load is essential to obtain low and constant friction coefficients. In ultrapure water, bilayers are not resistant and have poor lubricant properties. On the other hand, in Tris saline buffer, they fully resist to indentation and exhibit low (micro=0.035) and stable friction coefficient with no visible wear during the 50 min of the friction test. The unbuffered saline solution improves the mechanical resistance to indentation but not the lubrication. These results suggest that the adsorption of ions to the zwiterrionic bilayers has different effects on the mechanical and tribological properties of bilayers: higher resistance to normal indentation due to an increase in bilayer cohesion, higher lubrication due to an increase in bilayer-bilayer repulsion. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Improvement of the respiration efficiency of Lactococcus lactis by decreasing the culture pH.

PubMed

Shi, Weijia; Li, Yu; Gao, Xueling; Fu, Ruiyan

2016-03-01

The growth characteristics and intracellular hemin concentrations of Lactococcus lactis grown under different culture pH and aeration conditions were examined to investigate the effect of culture pH on the respiration efficiency of L. lactis NZ9000 (pZN8148). Cell biomass and biomass yield of L. lactis grown with 4 μg hemin/ml and O2 were higher than those without aeration when the culture pH was controlled at 5-6.5. The culture pH affected the respiratory efficiency in the following order of pH: 5 > 5.5 > 6 > 6.5; the lag phase increased as the culture pH decreased. Hemin accumulation was sensitive to culture pH. Among the four pH conditions, pH 5.5 was optimal for hemin accumulation in the cells. The highest intracellular hemin level in L. lactis resting cells incubated at different pH saline levels (5-6.5) was at pH 5.5. The respiration efficiency of L. lactis under respiration-permissive conditions increases markedly as the culture pH decreases. These results may help develop high cell-density L. lactis cultures. Thus, this microorganism may be used for industrial applications.

Indicators: Salinity

EPA Pesticide Factsheets

Salinity is the dissolved salt content of a body of water. Excess salinity, due to evaporation, water withdrawal, wastewater discharge, and other sources, is a chemical sterssor that can be toxic for aquatic environments.

Salinization of groundwater around underground LPG storage caverns, Korea : statistical interpretation

NASA Astrophysics Data System (ADS)

Lee, J.; Chang, H.

2001-12-01

In this research, we investigate the reciprocal influence between groundwater flow and its salinization occurred in two underground cavern sites, using major ion chemistry, PCA for chemical analysis data, and cross-correlation for various hydraulic data. The study areas are two underground LPG storage facilities constructed in South Sea coast, Yosu, and West Sea coastal regions, Pyeongtaek, Korea. Considerably high concentration of major cations and anions of groundwaters at both sites showed brackish or saline water types. In Yosu site, some great chemical difference of groundwater samples between rainy and dry season was caused by temporal intrusion of high-saline water into propane and butane cavern zone, but not in Pyeongtaek site. Cl/Br ratios and δ 18O- δ D distribution for tracing of salinization source water in both sites revealed that two kind of saline water (seawater and halite-dissolved solution) could influence the groundwater salinization in Yosu site, whereas only seawater intrusion could affect the groundwater chemistry of the observation wells in Pyeongtaek site. PCA performed by 8 and 10 chemical ions as statistical variables in both sites showed that intensive intrusion of seawater through butane cavern was occurred at Yosu site while seawater-groundwater mixing was observed at some observation wells located in the marginal part of Pyeongtaek site. Cross-correlation results revealed that the positive relationship between hydraulic head and cavern operating pressure was far more conspicuous at propane cavern zone in both sites (65 ~90% of correlation coefficients). According to the cross-correlation results of Yosu site, small change of head could provoke massive influx of halite-dissolved solution from surface through vertically developed fracture networks. However in Pyeongtaek site, the pressure-sensitive observation wells are not completely consistent with seawater-mixed wells, and the hydraulic change of heads at these wells related to the

Effect of the phosphogypsum amendment of saline and agricultural soils on growth, productivity and antioxidant enzyme activities of tomato (Solanum lycopersicum L.).

PubMed

Smaoui-Jardak, Mariem; Kriaa, Walid; Maalej, Mohamed; Zouari, Mohamed; Kamoun, Lotfi; Trabelsi, Wassim; Ben Abdallah, Ferjani; Elloumi, Nada

2017-10-01

The objective of this study was to investigate the effects of phosphogypsum (PG) amendment on the physiochemical proprieties of saline and agricultural soils along with the growth, productivity and antioxidant enzyme activities of tomato plants ( Solanum lycopersicum L.) grown on the amended soils under controlled conditions. Obtained results showed that the amendment of saline soil (H) by PG induced a decrease in pH as well as in electrical conductivity. However, for the non saline soil (MC), there was a decrease in pH associated with an increase in electrical conductivity. For both soils, PG amendment led to an increase in Calcium (Ca) and sodium (Na), and a decrease in potassium (K) in plant tissues. Cadmium (Cd), Zinc (Zn) and Chromium (Cr) contents in different parts of plants increased in proportion with PG concentration in the soils. Apart from Cd, all the analyzed metals in tomato fruit were found to be below the recommended maximum allowable concentration (MAC). Our results showed that PG application, at doses not exceeding 20%, seems to be beneficial for growth, photosynthetic activity and productivity of tomato plants as well as in decreasing salinity of saline soils. In these conditions, the use of PG could be a promising project for the rehabilitation of marginalized and saline ecosystems with either ornamental or non-fruit species. For both soils, a significant accumulation of MDA in shoots was detected, reflecting cell membrane damage especially when the PG amendment reached 20%. Beyond 20 and 40% PG, tomato plants developed an enzymatic antioxidant defense system in response to salinity and heavy metal stress. However, at 80% PG, enzymes activities were significantly inhibited.

ISFET pH Sensitivity: Counter-Ions Play a Key Role.

PubMed

Parizi, Kokab B; Xu, Xiaoqing; Pal, Ashish; Hu, Xiaolin; Wong, H S Philip

2017-02-02

The Field Effect sensors are broadly used for detecting various target analytes in chemical and biological solutions. We report the conditions under which the pH sensitivity of an Ion Sensitive Field Effect transistor (ISFET) sensor can be significantly enhanced. Our theory and simulations show that by using pH buffer solutions containing counter-ions that are beyond a specific size, the sensor shows significantly higher sensitivity which can exceed the Nernst limit. We validate the theory by measuring the pH response of an extended gate ISFET pH sensor. The consistency and reproducibility of the measurement results have been recorded in hysteresis free and stable operations. Different conditions have been tested to confirm the accuracy and validity of our experiment results such as using different solutions, various oxide dielectrics as the sensing layer and off-the-shelf versus IC fabricated transistors as the basis of the ISFET sensor.

Effects of salinity and the extent of water on supercritical CO2-induced phlogopite dissolution and secondary mineral formation.

PubMed

Shao, Hongbo; Ray, Jessica R; Jun, Young-Shin

2011-02-15

To ensure the viability of geologic CO2 sequestration (GCS), we need a holistic understanding of reactions at supercritical CO2 (scCO2)-saline water-rock interfaces and the environmental factors affecting these interactions. This research investigated the effects of salinity and the extent of water on the dissolution and surface morphological changes of phlogopite [KMg2.87Si3.07Al1.23O10(F,OH)2], a model clay mineral in potential GCS sites. Salinity enhanced the dissolution of phlogopite and affected the location, shape, size, and phase of secondary minerals. In low salinity solutions, nanoscale particles of secondary minerals formed much faster, and there were more nanoparticles than in high salinity solutions. The effect of water extent was investigated by comparing scCO2-H2O(g)-phlogopite and scCO2-H2O(l)-phlogopite interactions. Experimental results suggested that the presence of a thin water film adsorbed on the phlogopite surface caused the formation of dissolution pits and a surface coating of secondary mineral phases that could change the physical properties of rocks. These results provide new information for understanding reactions at scCO2-saline water-rock interfaces in deep saline aquifers and will help design secure and environmentally sustainable CO2 sequestration projects.

Mapping Soil Salinity/Sodicity by using Landsat OLI Imagery and PLSR Algorithm over Semiarid West Jilin Province, China

PubMed Central

Liu, Mingyue; Du, Baojia; Zhang, Bai

2018-01-01

Soil salinity and sodicity can significantly reduce the value and the productivity of affected lands, posing degradation, and threats to sustainable development of natural resources on earth. This research attempted to map soil salinity/sodicity via disentangling the relationships between Landsat 8 Operational Land Imager (OLI) imagery and in-situ measurements (EC, pH) over the west Jilin of China. We established the retrieval models for soil salinity and sodicity using Partial Least Square Regression (PLSR). Spatial distribution of the soils that were subjected to hybridized salinity and sodicity (HSS) was obtained by overlay analysis using maps of soil salinity and sodicity in geographical information system (GIS) environment. We analyzed the severity and occurring sizes of soil salinity, sodicity, and HSS with regard to specified soil types and land cover. Results indicated that the models’ accuracy was improved by combining the reflectance bands and spectral indices that were mathematically transformed. Therefore, our results stipulated that the OLI imagery and PLSR method applied to mapping soil salinity and sodicity in the region. The mapping results revealed that the areas of soil salinity, sodicity, and HSS were 1.61 × 106 hm2, 1.46 × 106 hm2, and 1.36 × 106 hm2, respectively. Also, the occurring area of moderate and intensive sodicity was larger than that of salinity. This research may underpin efficiently mapping regional salinity/sodicity occurrences, understanding the linkages between spectral reflectance and ground measurements of soil salinity and sodicity, and provide tools for soil salinity monitoring and the sustainable utilization of land resources. PMID:29614727

Saline infusion sonohysterography.

PubMed

2004-01-01

Saline infusion sonohysterography consists of ultrasonographic imaging of the uterus and uterocervical cavity, using real-time ultrasonography during injection of sterile saline into the uterus. When properly performed, saline infusion sonohysterography can provide information about the uterus and endometrium. The most common indication for sonohysterography is abnormal uterine bleeding. sonohysterography should not be performed in a woman who is pregnant or could be pregnant or in a woman with a pelvic infection or unexplained pelvic tenderness. Physicians who perform or supervise diagnostic saline infusion sonohysterograpy should have training, experience, and demonstrated competence in gynecologic ultrasonography and saline infusion sonohysterography. Portions of this document were developed jointly with the American College of Radiology and the American Institute of Ultrasound in Medicine.

Simple new method for effective concentration of 188Re solutions from alumina-based 188W-188Re generator.

PubMed

Guhlke, S; Beets, A L; Oetjen, K; Mirzadeh, S; Biersack, H J; Knapp, F F

2000-07-01

(188)Re is a useful generator-produced radioisotope currently under evaluation for a variety of therapeutic applications, including bone pain palliation and intravascular radiation therapy. Because the (188)W parent is available only in a relatively low specific activity (<0.15-0.19 GBq/mg) from reactor irradiation of enriched (186)W, relatively large volumes of 0.9% saline (>15 mL) are required for elution of the (188)Re daughter from traditional alumina-based (188)W-(188)Re generators. Because these large bolus volumes result in solutions with a relatively low specific volume activity of (188)Re (<1 GBq/mL for the 18.5-GBq generator), the availability of effective methods for eluent concentration is important. Our new approach is based on the use of 0.3 mol/L ammonium acetate as a representative salt of a weak acid instead of saline for generator elution. After generator elution, the ammonium acetate generator eluent (15-20 mL) is passed through a tandem IC-H Plus cation (Dowex-H)-anion (QMA Light) column system. Exchange of ammonium cations with hydrogen ions on the cation column forms an acetic acid solution containing perrhenate anions from which the macroscopic levels of the acetate anion of the eluent have been effectively removed. Because perrhenic acid is fully dissociated at this pH, the QMA Light column specifically traps the (188)Re-perrhenate, which is subsequently eluted with a low volume (<1 mL) of saline. Concentration ratios greater than 20:1 are readily achieved with this method. A typical clinical-scale generator loaded with 19.2 GBq (188)W was used to validate the approach. Saline elution provided (188)Re in a 75%-80% yield. Although elution with 0.15 mol/L NH4OAc gave lower yields (55%-60%), use of 0.3 mol/L NH4OAc provided yields comparable with those of saline (70%-75%). (188)W parent breakthrough was not detected after passage of the bolus through the tandem concentration system. Bolus volumes of 15-20 mL, which initially contained as much

Continuous pH monitoring in a perfused bioreactor system using an optical pH sensor

NASA Technical Reports Server (NTRS)

Jeevarajan, Antony S.; Vani, Sundeep; Taylor, Thomas D.; Anderson, Melody M.

2002-01-01

Monitoring and regulating the pH of the solution in a bioprocess is one of the key steps in the success of bioreactor operation. An in-line optical pH sensor, based on the optical absorption properties of phenol red present in the medium, was developed and tested in this work for use in NASA space bioreactors based on a rotating wall-perfused vessel system supporting a baby hamster kidney (BHK-21) cell culture. The sensor was tested over three 30-day and one 124-day cell runs. The pH sensor initially was calibrated and then used during the entire cell culture interval. The pH reported by the sensor was compared to that measured by a fiber optically coupled Shimadzu spectrophotometer and a blood gas analyzer. The maximum standard error of prediction for all the four cell runs for development pH sensor against BGA was +/-0.06 pH unit and for the fiber optically coupled Shimadzu spectrophotometer against the blood gas analyzer was +/-0.05 pH unit. The pH sensor system performed well without need of recalibration for 124 days. Copyright 2002 Wiley Periodicals, Inc.

Effects of nitrogen fertilization on the acidity and salinity of greenhouse soils.

PubMed

Han, Jiangpei; Shi, Jiachun; Zeng, Lingzao; Xu, Jianming; Wu, Laosheng

2015-02-01

A greenhouse pot experiment was conducted to study the effects of conventional nitrogen fertilization on soil acidity and salinity. Three N rates (urea; N0, 0 kg N ha(-1); N1, 600 kg N ha(-1); and N2, 1,200 kg N ha(-1)) were applied in five soils with different greenhouse cultivation years to evaluate soil acidification and salinization rate induced by nitrogen fertilizer in lettuce production. Both soil acidity and salinity increased significantly as N input increased after one season, with pH decrease ranging from 0.45 to 1.06 units and electrolytic conductivity increase from 0.24 to 0.68 mS cm(-1). An estimated 0.92 mol H(+) was produced for 1 mol (NO2 (-) + NO3 (-))-N accumulation in soil. The proton loading from nitrification was 14.3-27.3 and 12.1-58.2 kmol H(+) ha(-1) in the center of Shandong Province under N1 and N2 rate, respectively. However, the proton loading from the uptake of excess bases by lettuces was only 0.3-4.5 % of that from nitrification. Moreover, the release of protons induced the direct release of base cations and accelerated soil salinization. The increase of soil acidity and salinity was attributed to the nitrification of excess N fertilizer. Compared to the proton loading by lettuce, nitrification contributed more to soil acidification in greenhouse soils.

Colorimetric Determination of pH.

ERIC Educational Resources Information Center

Tucker, Sheryl; And Others

1989-01-01

Presented is an activity in which the pH of a solution can be quantitatively measured using a spectrophotometer. The theory, experimental details, sample preparation and selection, instrumentation, and results are discussed. (CW)

The effect of a new formaldehyde-free binder on the dissolution rate of glass wool fibre in physiological saline solution.

PubMed

Potter, Russell M; Olang, Nassreen

2013-04-12

The in-vitro dissolution rate of fibres is a good predictor of the in-vivo behavior and potential health effects of inhaled fibres. This study examines the effect of a new formaldehyde-free carbohydrate-polycarboxylic acid binder on the in-vitro dissolution rate of biosoluble glass fibres. Dissolution rate measurements in pH 7.4 physiological saline solution show that the presence of the binder on wool insulation glass fibres has no effect on their dissolution. There is no measurable difference between the dissolution rates of continuous draw fibres before and after binder was applied by dipping. Nor is there a measurable difference between the dissolution rates of a production glass wool sample with binder and that same sample after removal of the binder by low-temperature ashing. Morphological examination shows that swelling of the binder in the solution is at least partially responsible for the development of open channels around the glass-binder interface early in the dissolution. These channels allow fluid to reach the entire glass surface under the binder coating. There is no evidence of any delay in the dissolution rate as a result of the binder coating.

The effect of a new formaldehyde-free binder on the dissolution rate of glass wool fibre in physiological saline solution

PubMed Central

2013-01-01

The in-vitro dissolution rate of fibres is a good predictor of the in-vivo behavior and potential health effects of inhaled fibres. This study examines the effect of a new formaldehyde-free carbohydrate-polycarboxylic acid binder on the in-vitro dissolution rate of biosoluble glass fibres. Dissolution rate measurements in pH 7.4 physiological saline solution show that the presence of the binder on wool insulation glass fibres has no effect on their dissolution. There is no measurable difference between the dissolution rates of continuous draw fibres before and after binder was applied by dipping. Nor is there a measurable difference between the dissolution rates of a production glass wool sample with binder and that same sample after removal of the binder by low-temperature ashing. Morphological examination shows that swelling of the binder in the solution is at least partially responsible for the development of open channels around the glass-binder interface early in the dissolution. These channels allow fluid to reach the entire glass surface under the binder coating. There is no evidence of any delay in the dissolution rate as a result of the binder coating. PMID:23587247

Structure and composition of oligohaline marsh plant communities exposed to salinity pulses

USGS Publications Warehouse

Howard, R.J.; Mendelssohn, I.A.

2000-01-01

The response of two oligohaline marsh macrophyte communities to pulses of increased salinity was studied over a single growing season in a greenhouse experiment. The plant communities were allowed a recovery period in freshwater following the pulse events. The experimental treatments included: (1) salinity influx rate (rate of salinity increase from 0 to 12 gl-1); (2) duration of exposure to elevated salinity; and (3) water depth. The communities both included Sagittaria lancifolia L.; the codominant species were Eleocharis palustris (L.) Roemer and J.A. Schultes in community 1 and Schoenoplectus americanus (Pers.) Volk. ex Schinz and R. Keller in community 2. Effects of the treatments on sediment chemical characteristics (salinity, pH, redox potential, and sulfide and ammonium concentrations) and plant community attributes (aboveground and belowground biomass, stem density, leaf tissue nutrients, and species richness) were examined. The treatment effects often interacted to influence sediment and plant communities characteristics following recovery in fresh water. Salinity influx rate per se, however, had little effect on the abiotic or biotic response variables; significant influx effects were found when the 0 gl-1 (zero influx) treatment was compared to the 12 gl-1 treatments, regardless of the rate salinity was raised. A salinity level of 12 gl-1 had negative effects on plant community structure and composition; these effects were usually associated with 3 months of salinity exposure. Water depth often interacted with exposure duration, but increased water depth did independently decrease the values of some community response measures. Community 1 was affected more than community 2 in the most extreme salinity treatment (3 months exposure/15-cm water depth). Although species richness in both communities was reduced, structural changes were more dramatic in community 1. Biomass and stem density were reduced in community 1 overall and in both dominant species

Reactive Solute Transport in Streams: 2. Simulation of a pH Modification Experiment

NASA Astrophysics Data System (ADS)

Runkel, Robert L.; McKnight, Diane M.; Bencala, Kenneth E.; Chapra, Steven C.

1996-02-01

We present an application of an equilibrium-based solute transport model to a pH-modification experiment conducted on the Snake River, an acidic, metal-rich stream located in the Rocky Mountains of Colorado. During the experiment, instream pH decreased from 4.2 to 3.2, causing a marked increase in dissolved iron concentrations. Model application requires specification of several parameters that are estimated using tracer techniques, mass balance calculations, and geochemical data. Two basic questions are addressed through model application: (1) What are the processes responsible for the observed increase in dissolved iron concentrations? (2) Can the identified processes be represented within the equilibrium-based transport model? Simulation results indicate that the increase in iron was due to the dissolution of hydrous iron oxides and the photoreduction of ferric iron. Dissolution from the streambed is represented by considering a trace compartment consisting of freshly precipitated hydrous iron oxide and an abundant compartment consisting of aged precipitates that are less soluble. Spatial variability in the solubility of hydrous iron oxide is attributed to heterogeneity in the streambed sediments, temperature effects, and/or variability in the effects of photoreduction. Solubility products estimated via simulation fall within a narrow range (pKsp from 40.2 to 40.8) relative to the 6 order of magnitude variation reported for laboratory experiments (pKsp from 37.3 to 43.3). Results also support the use of an equilibrium-based transport model as the predominate features of the iron and pH profiles are reproduced. The model provides a valuable tool for quantifying the nature and extent of pH-dependent processes within the context of hydrologic transport.

Stability of Adrenaline in Irrigating Solution for Intraocular Surgery.

PubMed

Shibata, Yuuka; Kimura, Yasuhiro; Taogoshi, Takanori; Matsuo, Hiroaki; Kihira, Kenji

2016-01-01

Intraocular irrigating solution containing 1 µg/mL adrenaline is widely used during cataract surgery to maintain pupil dilation. Prepared intraocular irrigating solutions are recommended for use within 6 h. After the irrigating solution is admistered for dilution, the adrenaline may become oxidized, and this may result in a decrease in its biological activity. However, the stability of adrenaline in intraocular irrigating solution is not fully understood. The aim of this study was to evaluate the stability of adrenaline in clinically used irrigating solutions of varying pH. Six hours after mixing, the adrenaline percentages remaining were 90.6%±3.7 (pH 7.2), 91.1%±2.2 (pH 7.5), and 65.2%±2.8 (pH 8.0) of the initial concentration. One hour after mixing, the percentages remaining were 97.6%±2.0 (pH 7.2), 97.4%±2.7 (pH 7.5), and 95.6%±3.3 (pH 8.0). The degradation was especially remarkable and time dependent in the solution at pH 8.0. These results indicate that the concentration of adrenaline is decreased after preparation. Moreover, we investigated the influence of sodium bisulfite on adrenaline stability in irrigating solution. The percentage adrenaline remaining at 6 h after mixing in irrigating solution (pH 8.0) containing sodium bisulfite at 0.5 µg/mL (concentration in irrigating solution) or at 500 µg/mL (concentration in the undiluted adrenaline preparation) were 57.5 and 97.3%, respectively. Therefore, the low concentration of sodium bisulfite in the irrigating solution may be a cause of the adrenaline loss. In conclusion, intraocular irrigation solution with adrenaline should be prepared just prior to its use in surgery.

Solution pH and oligoamine molecular weight dependence of the transition from monolayer to multilayer adsorption at the air-water interface from sodium dodecyl sulfate/oligoamine mixtures.

PubMed

Halacheva, S S; Penfold, J; Thomas, R K; Webster, J R P

2013-05-14

Neutron reflectivity and surface tension have been used to investigate the solution pH and oligoamine molecular weight dependence of the adsorption of sodium dodecyl sulfate (SDS)/oligoamine mixtures at the air-water interface. For diethylenetriamine, triamine, or triethylenetetramine, tetramine mixed with SDS, there is monolayer adsorption at pH 7 and 10, and multilayer adsorption at pH 3. For the slightly higher molecular weight tetraethylenepentamine, pentamine, and pentaethylenehexamine, hexamine, the adsorption is in the form of a monolayer at pH 3 and multilayers at pH 7 and 10. Hence, there is a pH driven transition from monolayer to multilayer adsorption, which shifts from low pH to higher pH as the oligoamine molecular weight increases from tetramine to pentamine. This results from the relative balance between the electrostatic attraction between the SDS and amine nitrogen group which decreases as the charge density decreases with increasing pH, the ion-dipole interaction between the amine nitrogen and SDS sulfate group which is dominant at higher pH, and the hydrophobic interalkyl chain interaction between bound SDS molecules which changes with oligoamine molecular weight.

Comparison of Irrigation Solutions and Devices in a Contaminated Musculoskeletal Wound Survival Model

DTIC Science & Technology

2009-01-01

greatest reduction was seen with castile soap, which lowered the photon count to 13% of the pretreatment level. This was followed by benzalkonium chloride ...castile soap was significantly greater than that with the normal saline solution (p = 0.0069), while the reductions with benzalkonium chloride (p...the goats were assigned to four treatment groups: normal saline solution, bacitracin solution, castile soap, and benzalkonium chloride . All wounds

Impact of the water salinity on the hydraulic conductivity of fen peat

NASA Astrophysics Data System (ADS)

Gosch, Lennart; Janssen, Manon; Lennartz, Bernd

2017-04-01

Coastal peatlands represent an interface between marine and terrestrial ecosystems; their hydrology is affected by salt and fresh water inflow alike. Previous studies on bog peat have shown that pore water salinity can have an impact on the saturated hydraulic conductivity (Ks) of peat because of chemical pore dilation effects. In this ongoing study, we are aiming at quantifying the impact of higher salinities (up to 3.5 %) on Ks of fen peat to get a better understanding of the water and solute exchange between coastal peatlands and the adjacent sea. Two approaches differing in measurement duration employing a constant-head upward-flow permeameter were conducted. At first, Ks was measured at an initial salinity for several hours before the salinity was abruptly increased and the measurement continued. In the second approach, Ks was measured for 15 min at the salt content observed during sampling. Then, samples were completely (de)salinized via diffusion for several days/weeks before a comparison measurement was carried out. The results for degraded fen peats show a decrease of Ks during long-term measurements which does not depend on the water salinity. A slow, diffusion-controlled change in salinity does not modify the overall outcome that the duration of measurements has a stronger impact on Ks than the salinity. Further experiments will show if fen peat soils differing in their state of degradation exhibit a different behavior. A preliminary conclusion is that salinity might have a less important effect on hydraulic properties of fen peat than it was observed for bog peat.

A prospective randomized trial of two solutions for intrapartum amnioinfusion: effects on fetal electrolytes, osmolality, and acid-base status.

PubMed

Pressman, E K; Blakemore, K J

1996-10-01

Our purpose was to compare the effects of intrapartum amnioinfusion with normal saline solution versus lactated Ringer's solution plus physiologic glucose on neonatal electrolytes and acid-base balance. Patients undergoing amnioinfusion for obstetric indications were randomized to receive normal saline solution or lactated Ringer's solution plus physiologic glucose at standardized amnioinfusion rates. Data were collected prospectively on maternal demographics, course of labor, and maternal and neonatal outcome. Arterial cord blood was obtained for analysis of electrolytes, glucose, osmolality, lactic acid, and blood gases. Control subjects with normal fetal heart rate patterns, and clear amniotic fluid not receiving amnioinfusion were studied concurrently. Data were collected on 59 patients (21 normal saline solution, 18 lactated Ringer's solution plus physiologic glucose, and 20 controls). Maternal demographics, course of labor, and neonatal outcome were similar in all three groups. Cesarean sections were performed more often in the amnioinfusion groups (33.3% for normal saline solution, 38.9% for lactated Ringer's solution plus physiologic glucose) than in the control group (5.0%), p < 0.05. Cord arterial electrolytes, glucose, osmolality, lactic acid, and blood gases were not altered by amnioinfusion with either solution. Intrapartum amnioinfusion with normal saline solution or lactated Ringer's solution plus physiologic glucose has no effect on neonatal electrolytes or acid-base balance.