Effect of Sintering Atmosphere and Solution Treatment on Density, Microstructure and Tensile Properties of Duplex Stainless Steels Developed from Pre-alloyed Powders

NASA Astrophysics Data System (ADS)

Murali, Arun Prasad; Mahendran, Sudhahar; Ramajayam, Mariappan; Ganesan, Dharmalingam; Chinnaraj, Raj Kumar

2017-10-01

In this research, Powder Metallurgy (P/M) of Duplex Stainless Steels (DSS) of different compositions were prepared through pre-alloyed powders and elemental powders with and without addition of copper. The powder mix was developed by pot mill for 12 h to obtain the homogeneous mixture of pre-alloyed powder with elemental compositions. Cylindrical green compacts with the dimensions of 30 mm diameter and 12 mm height were compacted through universal testing machine at a pressure level of 560 ± 10 MPa. These green compacts were sintered at 1350 °C for 2 h in hydrogen and argon atmospheres. Some of the sintered stainless steel preforms were solution treated at 1050 °C followed by water quenching. The sintered as well as solution treated samples were analysed by metallography examination, Scanning Electron Microscopy and evaluation of mechanical properties. Ferrite content of sintered and solution treated DSS were measured by Fischer Ferritoscope. It is inferred that the hydrogen sintered DSS depicted better density (94% theoretical density) and tensile strength (695 MPa) than the argon sintered steels. Similarly the microstructure of solution treated DSS revealed existence of more volume of ferrite grains than its sintered condition. Solution treated hydrogen sintered DSS A (50 wt% 316L + 50 wt% 430L) exhibited higher tensile strength of 716 MPa and elongation of 17%, which are 10-13% increment than the sintered stainless steels.

Amount of leachant and water absorption levels of wood treated with borates and water repellents.

PubMed

Baysal, Ergun; Sonmez, Abdullah; Colak, Mehmet; Toker, Hilmi

2006-12-01

Wood protection efficacy of borates against biological agents, flame retardancy, and suitability to the environment is well known. Since borates can be applied to timber as water based solutions, they are preferred economically as well. Even though they are highly mobile in wood, boron compounds are widely used in timber preservation. Borates migrate in liquid and increase the hygroscopicity of wood in damp conditions. This study deals with the physical restriction of water access in wood by impregnating water repellent agents into wood to limit amount of leachant and water absorption levels of wood after boron treatment. Borates were incorporated with polyethylene glycol-400 (PEG-400) their bulking effect in wood was considered. Results indicated that the amount of leachates from wood treated with borates in PEG-400 was remarkably higher compared to those of wood treated with the aqueous solutions of borates. Water absorption (WA) levels of wood treated with aqueous solutions of borates were higher than those of their treated samples with the solutions in PEG-400. Secondary treatments of wood with the water repellent (WR) chemicals following borate impregnation reduced the leaching of chemicals from wood in water and also WA of the specimens were less than those of the wood treated with only borates from aqueous and PEG solutions. Styrene (St) was the most effective monomer among the other agents used in terms of immobility effect on borates and WA.

Microwave-Hydrothermal Treated Grape Peel as an Efficient Biosorbent for Methylene Blue Removal

PubMed Central

Ma, Lin; Jiang, Chunhai; Lin, Zhenyu; Zou, Zhimin

2018-01-01

Biosorption using agricultural wastes has been proven as a low cost and efficient way for wastewater treatment. Herein, grape peel treated by microwave- and conventional-hydrothermal processes was used as low cost biosorbent to remove methylene blue (MB) from aqueous solutions. The adsorption parameters including the initial pH value, dosage of biosorbents, contact time, and initial MB concentration were investigated to find the optimum adsorption conditions. The biosorbent obtained by microwave-hydrothermal treatment only for 3 min at 180 °C (microwave-hydrothermal treated grape peel, MGP) showed faster kinetics and higher adsorption capability than that produced by a conventional-hydrothermal process (hydrothermal treated grape peel, HGP) with a duration time of 16 h. The maximum adsorption capability of MGP under the optimum conditions (pH = 11, a dosage of 2.50 g/L) as determined with the Langmuir model reached 215.7 mg/g, which was among the best values achieved so far on biosorbents. These results demonstrated that the grape peel treated by a quick microwave-hydrothermal process can be a very promising low cost and efficient biosorbent for organic dye removal from aqueous solutions. PMID:29385041

On the Flow of a Compressible Fluid by the Hodograph Method. II - Fundamental Set of Particular Flow Solutions of the Chaplygin Differential Equation

NASA Technical Reports Server (NTRS)

Garrick, I. E.; Kaplan, Carl

1944-01-01

The differential equation of Chaplygin's jet problem is utilized to give a systematic development of particular solutions of the hodograph flow equations, which extends the treatment of Chaplygin into the supersonic range and completes the set of particular solutions. The particular solutions serve to place on a reasonable basis the use of velocity correction formulas for the comparison of incompressible and compressible flows. It is shown that the geometric-mean type of velocity correction formula introduced in part I has significance as an over-all type of approximation in the subsonic range. A brief review of general conditions limiting the potential flow of an adiabatic compressible fluid is given and application is made to the particular solutions, yielding conditions for the existence of singular loci in the supersonic range. The combining of particular solutions in accordance with prescribed boundary flow conditions is not treated in the present paper.

PROCESS OF TREATING OR FORMING AN INSOLUBLE PLUTONIUM PRECIPITATE IN THE PRESENCE OF AN ORGANIC ACTIVE AGENT

DOEpatents

Balthis, J.H.

1961-07-18

Carrier precipitation processes for the separation of plutonium from fission products are described. In a process in which an insoluble precipitate is formed in a solution containing plutonium and fission products under conditions whereby plutonium is carried by the precipitate, and the precipitate is then separated from the remaining solution, an organic surface active agent is added to the mixture of precipitate and solution prior to separation of the precipitate from the supernatant solution, thereby improving the degree of separation of the precipitate from the solution.

Comparison of sodium hydroxide and calcium hydroxide pretreatments on the enzymatic hydrolysis and lignin recovery of sugarcane bagasse.

PubMed

Chang, Menglei; Li, Denian; Wang, Wen; Chen, Dongchu; Zhang, Yuyuan; Hu, Huawen; Ye, Xiufang

2017-11-01

Sodium hydroxide (NaOH) and calcium hydroxide (Ca(OH) 2 ) respectively dissolved in water and 70% glycerol were applied to treat sugarcane bagasse (SCB) under the condition of 80°C for 2h. NaOH solutions could remove more lignin and obtain higher enzymatic hydrolysis efficiency of SCB than Ca(OH) 2 solutions. Compared with the alkali-water solutions, the enzymatic hydrolysis of SCB treated in NaOH-glycerol solution decreased, while that in Ca(OH) 2 -glycerol solution increased. The lignin in NaOH-water pretreatment liquor could be easily recovered by calcium chloride (CaCl 2 ) at room temperature, but that in Ca(OH) 2 -water pretreatment liquor couldn't. NaOH pretreatment is more suitable for facilitating enzymatic hydrolysis and lignin recovery of SCB than Ca(OH) 2 pretreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of titanium soaked in 5 M NaOH or 5 M KOH solutions

PubMed Central

Kim, Christina; Kendall, Matthew R.; Miller, Matthew A.; Long, Courtney L.; Larson, Preston R.; Humphrey, Mary Beth; Madden, Andrew S.; Tas, A. Cuneyt

2012-01-01

Commercially pure titanium plates/coupons and pure titanium powders were soaked for 24 h in 5 M NaOH and 5 M KOH solutions, under identical conditions, over the temperature range of 37° to 90°C. Wettability of the surfaces of alkali-treated cpTi coupons were studied by using contact angle goniometry. cpTi coupons soaked in 5 M NaOH or 5 M KOH solutions were found to have hydrophilic surfaces. Hydrous alkali titanate nanofibers and nanotubes were identified with SEM/EDXS and grazing incidence XRD. Surface areas of Ti powders increased >50–220 times, depending on the treatment, when soaked in the above solutions. A solution was developed to coat amorphous calcium phosphate, instead of hydroxyapatite, on Ti coupon surfaces. In vitro cell culture tests were performed with osteoblast-like cells on the alkali-treated samples. PMID:23565038

Technical Note: Approximate solution of transient drawdown for constant-flux pumping at a partially penetrating well in a radial two-zone confined aquifer

NASA Astrophysics Data System (ADS)

Huang, C.-S.; Yang, S.-Y.; Yeh, H.-D.

2015-03-01

An aquifer consisting of a skin zone and a formation zone is considered as a two-zone aquifer. Existing solutions for the problem of constant-flux pumping (CFP) in a two-zone confined aquifer involve laborious calculation. This study develops a new approximate solution for the problem based on a mathematical model including two steady-state flow equations with different hydraulic parameters for the skin and formation zones. A partially penetrating well may be treated as the Neumann condition with a known flux along the screened part and zero flux along the unscreened part. The aquifer domain is finite with an outer circle boundary treated as the Dirichlet condition. The steady-state drawdown solution of the model is derived by the finite Fourier cosine transform. Then, an approximate transient solution is developed by replacing the radius of the boundary in the steady-state solution with an analytical expression for a dimensionless time-dependent radius of influence. The approximate solution is capable of predicting good temporal drawdown distributions over the whole pumping period except at the early stage. A quantitative criterion for the validity of neglecting the vertical flow component due to a partially penetrating well is also provided. Conventional models considering radial flow without the vertical component for the CFP have good accuracy if satisfying the criterion.

PROCESS OF RECOVERING URANIUM FROM ITS ORES

DOEpatents

Galvanek, P. Jr.

1959-02-24

A process is presented for recovering uranium from its ores. The crushed ore is mixed with 5 to 10% of sulfuric acid and added water to about 5 to 30% of the weight of the ore. This pugged material is cured for 2 to 3 hours at 100 to 110 deg C and then cooled. The cooled mass is nitrate-conditioned by mixing with a solution equivalent to 35 pounds of ammunium nitrate and 300 pounds of water per ton of ore. The resulting pulp containing 70% or more solids is treated by upflow percolation with a 5% solution of tributyl phosphate in kerosene at a rate equivalent to a residence time of about one hour to extract the solubilized uranium. The uranium is recovered from the pregnant organic liquid by counter-current washing with water. The organic extractant may be recycled. The uranium is removed from the water solution by treating with ammonia to precipitate ammonium diuranate. The filtrate from the last step may be recycled for the nitrate-conditioning treatment.

Conformation Types of Ubiquitin [M+8H]8+ Ions from Water:Methanol Solutions: Evidence for the N and A States in Aqueous Solution

PubMed Central

Shi, Huilin; Pierson, Nicholas A.; Valentine, Stephen J.; Clemmer, David E.

2012-01-01

Ion mobility and mass spectrometry measurements are used to examine the gas-phase populations of [M+8H]8+ ubiquitin ions formed upon electrospraying 20 different solutions: from 100:0 to 5:95 water:methanol that are maintained at pH = 2.0. Over this range of solution conditions, mobility distributions for the +8 charge state show substantial variations. Here we develop a model that treats the combined measurements as one data set. By varying the relative abundances of a discrete set of conformation types, it is possible to represent distributions obtained from any solution. For solutions that favor the well-known A-state ubiquitin, it is possible to represent the gas-phase distributions with seven conformation types. Aqueous conditions that favor the native structure require four more structural types to represent the distribution. This analysis provides the first direct evidence for trace amounts of the A state under native conditions. The method of analysis presented here should help illuminate how solution populations evolve into new gas-phase structures as solvent is removed. Evidence for trace quantities of previously unknown states under native solution conditions may provide insight about the relationship of dynamics to protein function as well as misfolding and aggregation phenomena. PMID:22315998

Intra-Wellbore Head Losses in a Horizontal Well with both Kinematic and Frictional Effects in an Anisotropic Confined Aquifer between Two Streams

NASA Astrophysics Data System (ADS)

Wang, Q.; Zhan, H.

2017-12-01

Horizontal drilling becomes an appealing technology for water exploration or aquifer remediation in recent decades, due to the decreasing operational cost and many technical advantages over the vertical wells. However, many previous studies on the flow into horizontal wells were based on the uniform flux boundary condition (UFBC) for treating horizontal wells, which could not reflect the physical processes of flow inside the well accurately. In this study, we investigated transient flow into a horizontal well in an anisotropic confined aquifer between two streams for three types of boundary conditions of treating the horizontal well, including UFBC, uniform head boundary condition (UHBC), and mixed-type boundary condition (MTBC). The MTBC model considered both kinematic and frictional effects inside the horizontal well, in which the kinematic effect referred to the accelerational and fluid inflow effects. The new solution of UFBC was derived by superimposing the point sink/source solutions along the axis of the horizontal well with a uniform strength. The solutions of UHBC and MTBC were obtained by a hybrid analytical-numerical method, and an iterative method was proposed to determine the minimum well segment number required to yield sufficiently accurate answer. The results showed that the differences among the UFBC, UHBC, MTBCFriction and MTBC solutions were obvious, in which MTBCFriction represented the solutions considering the frictional effect but ignoring the kinematic effect. The MTBCFriction and MTBC solutions were sensitive to the flow rate, and the difference of these two solutions increases with the flow rate, suggesting that the kinematic effect could not be ignored for studying flow to a horizontal well, especially when the flow rate is great. The well specific inflow (WSI) (which is the inflow per unit screen length at a specified location of the horizontal well) increased with the distance along the wellbore for the MTBC model at early stage, while the minimum WSI moved to the well center with time going, following a cubic polynomial function.

Geochemical modeling of reactions and partitioning of trace metals and radionuclides during titration of contaminated acidic sediments.

PubMed

Zhang, Fan; Luo, Wensui; Parker, Jack C; Spalding, Brian P; Brooks, Scott C; Watson, David B; Jardine, Philip M; Gu, Baohua

2008-11-01

Many geochemical reactions that control aqueous metal concentrations are directly affected by solution pH. However, changes in solution pH are strongly buffered by various aqueous phase and solid phase precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior of the soil-solution system is thus critical to predict metal transport under variable pH conditions. This studywas undertaken to develop a practical generic geochemical modeling approach to predict aqueous and solid phase concentrations of metals and anions during conditions of acid or base additions. The method of Spalding and Spalding was utilized to model soil buffer capacity and pH-dependent cation exchange capacity by treating aquifer solids as a polyprotic acid. To simulate the dynamic and pH-dependent anion exchange capacity, the aquifer solids were simultaneously treated as a polyprotic base controlled by mineral precipitation/ dissolution reactions. An equilibrium reaction model that describes aqueous complexation, precipitation, sorption and soil buffering with pH-dependent ion exchange was developed using HydroGeoChem v5.0 (HGC5). Comparison of model results with experimental titration data of pH, Al, Ca, Mg, Sr, Mn, Ni, Co, and SO4(2-) for contaminated sediments indicated close agreement suggesting that the model could potentially be used to predictthe acid-base behavior of the sediment-solution system under variable pH conditions.

Influence of Chemical Composition on Rupture Properties at 1200 Degrees F. of Forged Chromium-Cobalt-Nickel-Iron Base Alloys in Solution-Treated and Aged Condition

NASA Technical Reports Server (NTRS)

Reynolds, E E; Freeman, J W; White, A E

1951-01-01

The influence of systematic variations of chemical composition on rupture properties at 1200 degrees F. was determined for 62 modifications of a basic alloy containing 20 percent chromium, 20 percent nickel, 20 percent cobalt, 3 percent molybdenum, 2 percent tungsten, 1 percent columbium, 0.15 percent carbon, 1.7 percent manganese, 0.5 percent silicon, 0.12 percent nitrogen and the balance iron. These modifications included individual variations of each of 10 elements present and simultaneous variations of molybdenum, tungsten, and columbium. Laboratory induction furnace heats were hot-forged to round bar stock, solution-treated at 2200 degrees F., and aged at 1400 degrees F. The melting and fabrication conditions were carefully controlled in order to minimize all variable effects on properties except chemical composition. Information is presented which indicates that melting and hot-working conditions play an important role in high-temperature properties of alloys of the type investigated.

Acoustic emission during tensile deformation of M250 grade maraging steel

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Chandan Kumar; Rajkumar, Kesavan Vadivelu; Chandra Rao, Bhaghi Purna; Jayakumar, Tamanna

2012-05-01

Acoustic emission (AE) generated during room temperature tensile deformation of varyingly heat treated (solution annealed and thermally aged) M250 grade maraging steel specimens have been studied. Deformation of microstructure corresponding to different heat treated conditions in this steel could be distinctly characterized using the AE parameters such as RMS voltage, counts and peak amplitude of AE hits (events).

Forging of Advanced Disk Alloy LSHR

NASA Technical Reports Server (NTRS)

Gabb, Timothy P.; Gayda, John; Falsey, John

2005-01-01

The powder metallurgy disk alloy LSHR was designed with a relatively low gamma precipitate solvus temperature and high refractory element content to allow versatile heat treatment processing combined with high tensile, creep and fatigue properties. Grain size can be chiefly controlled through proper selection of solution heat treatment temperatures relative to the gamma precipitate solvus temperature. However, forging process conditions can also significantly influence solution heat treatment-grain size response. Therefore, it is necessary to understand the relationships between forging process conditions and the eventual grain size of solution heat treated material. A series of forging experiments were performed with subsequent subsolvus and supersolvus heat treatments, in search of suitable forging conditions for producing uniform fine grain and coarse grain microstructures. Subsolvus, supersolvus, and combined subsolvus plus supersolvus heat treatments were then applied. Forging and subsequent heat treatment conditions were identified allowing uniform fine and coarse grain microstructures.

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.

The effect of intra-wellbore head losses in a vertical well

NASA Astrophysics Data System (ADS)

Wang, Quanrong; Zhan, Hongbin

2017-05-01

Flow to a partially penetrating vertical well is made more complex by intra-wellbore losses. These are caused not only by the frictional effect, but also by the kinematic effect, which consists of the accelerational and fluid inflow effects inside a wellbore. Existing models of flow to a partially penetrating vertical well assume either a uniform-flux boundary condition (UFBC) or a uniform-head boundary condition (UHBC) for treating the flow into the wellbore. Neither approach considers intra-wellbore losses. In this study a new general solution, named the mixed-type boundary condition (MTBC) solution, is introduced to include intra-wellbore losses. It is developed from the existing solutions using a hybrid analytical-numerical method. The MTBC solution is capable of modeling various types of aquifer tests (constant-head tests, constant-rate tests, and slug tests) for partially or fully penetrating vertical wells in confined aquifers. Results show that intra-wellbore losses (both frictional and kinematic) can be significant in the early pumping stage. At later pumping times the UHBC solution is adequate because the difference between the MTBC and UHBC solutions becomes negligible.

Technical Note: Approximate solution of transient drawdown for constant-flux pumping at a partially penetrating well in a radial two-zone confined aquifer

NASA Astrophysics Data System (ADS)

Huang, C.-S.; Yang, S.-Y.; Yeh, H.-D.

2015-06-01

An aquifer consisting of a skin zone and a formation zone is considered as a two-zone aquifer. Existing solutions for the problem of constant-flux pumping in a two-zone confined aquifer involve laborious calculation. This study develops a new approximate solution for the problem based on a mathematical model describing steady-state radial and vertical flows in a two-zone aquifer. Hydraulic parameters in these two zones can be different but are assumed homogeneous in each zone. A partially penetrating well may be treated as the Neumann condition with a known flux along the screened part and zero flux along the unscreened part. The aquifer domain is finite with an outer circle boundary treated as the Dirichlet condition. The steady-state drawdown solution of the model is derived by the finite Fourier cosine transform. Then, an approximate transient solution is developed by replacing the radius of the aquifer domain in the steady-state solution with an analytical expression for a dimensionless time-dependent radius of influence. The approximate solution is capable of predicting good temporal drawdown distributions over the whole pumping period except at the early stage. A quantitative criterion for the validity of neglecting the vertical flow due to a partially penetrating well is also provided. Conventional models considering radial flow without the vertical component for the constant-flux pumping have good accuracy if satisfying the criterion.

Current research on shear buckling and thermal loads with PASCO: Panel Analysis and Sizing Code

NASA Technical Reports Server (NTRS)

Stroud, W. J.; Greene, W. H.; Anderson, M. S.

1981-01-01

The PASCO computer program to obtain the detailed dimensions of optimum stiffened composite structural panels is described. Design requirements in terms of inequality constraints can be placed on buckling loads or vibration frequencies, lamina stresses and strains, and overall panel stiffness for each of many load conditions. General panel cross sections can be treated. An analysis procedure involving a smeared orthotropic solution was investigated. The conservatism in the VIPASA solution and the danger in a smeared orthotropic solution is explored. PASCO's capability to design for thermal loadings is also described. It is emphasized that design studies illustrate the importance of the multiple load condition capability when thermal loads are present.

Factors affecting sodium hypochlorite extraction of CCA from treated wood.

PubMed

Gezer, E D; Cooper, P A

2009-12-01

Significant amounts of chromated copper arsenate (CCA) treated wood products, such as utility poles and residential construction wood, remain in service. There is increasing public concern about environmental contamination from CCA-treated wood when it is removed from service for reuse or recycling, placed in landfills or burned in commercial incinerators. In this paper, we investigated the effects of time, temperature and sodium hypochlorite concentration on chromium oxidation and extraction of chromated copper arsenate from CCA-treated wood (Type C) removed from service. Of the conditions evaluated, reaction of milled wood with sodium hypochlorite for one hour at room temperature followed by heating at 75 degrees C for two hours gave the highest extraction efficiency. An average of 95% Cr, 99% Cu and 96% As could be removed from CCA-treated, milled wood by this process. Most of the extracted chromium was oxidized to the hexavalent state and could therefore be recycled in a CCA treating solution. Sodium hypochlorite extracting solutions could be reused several times to extract CCA components from additional treated wood samples.

Effect of Er:YAG laser-activated irrigation solution on Enterococcus Faecalis biofilm in an ex-vivo root canal model.

PubMed

Sahar-Helft, Sharonit; Stabholtz, Adam; Moshonov, Joshua; Gutkin, Vitaly; Redenski, Idan; Steinberg, Doron

2013-07-01

Abstract Objective: The purpose of this study was to evaluate mineral content and surface morphology of root canals coated with Enterococcus faecalis biofilm after treatment with several endodontic irrigation solutions, with and without Er:YAG laser-activated irrigation (LAI). LAI has been introduced as a powerful method for root canal irrigation resulting in smear-layer removal from the root canal wall. Distal and palatal roots from 60 freshly extracted human molars were used in this study. The coronal of each tooth was removed. Roots were split longitudinally and placed in an ultrasonic bath to remove the smear layer, creating conditions for the formation of E. faecalis biofilm. After incubation, the two halves were reassembled in impression material to simulate clinical conditions. Specimens were divided into two main groups: roots rinsed with irrigation solutions and roots subjected to laser irradiation combined with irrigation solutions. Solutions tested were 2% chlorhexidine and 17% ethylenediaminetetraacetic acid (EDTA) and saline. Surface morphology: 17% EDTA irrigant solution combined with Er:YAG laser showed the best results for removing bacteria from the root canal walls. Chemical analysis: all samples treated with combined laser irradiation and irrigation solution had low surface levels of Ca compared with samples treated with irrigation alone. The Ca/P ratio was highest in the laser-EDTA group. Overall, mineral changes caused by laser with irrigation solutions were minimal, and statistically nonsignificant. In vitro irrigation solutions, combined with Er:YAG laser irradiation, were effective in removing E. faecalis biofilm from root canal walls. Irrigation solutions without laser irradiation were less effective, leaving a layer of biofilm on the dentin surface.

Nonlinear grid error effects on numerical solution of partial differential equations

NASA Technical Reports Server (NTRS)

Dey, S. K.

1980-01-01

Finite difference solutions of nonlinear partial differential equations require discretizations and consequently grid errors are generated. These errors strongly affect stability and convergence properties of difference models. Previously such errors were analyzed by linearizing the difference equations for solutions. Properties of mappings of decadence were used to analyze nonlinear instabilities. Such an analysis is directly affected by initial/boundary conditions. An algorithm was developed, applied to nonlinear Burgers equations, and verified computationally. A preliminary test shows that Navier-Stokes equations may be treated similarly.

Numerical Boundary Condition Procedures

NASA Technical Reports Server (NTRS)

1981-01-01

Topics include numerical procedures for treating inflow and outflow boundaries, steady and unsteady discontinuous surfaces, far field boundaries, and multiblock grids. In addition, the effects of numerical boundary approximations on stability, accuracy, and convergence rate of the numerical solution are discussed.

Effect of zone size on the convergence of exact solutions for diffusion in single phase systems with planar, cylindrical or spherical geometry

NASA Technical Reports Server (NTRS)

Unnam, J.; Tenney, D. R.

1981-01-01

Exact solutions for diffusion in single phase binary alloy systems with constant diffusion coefficient and zero-flux boundary condition have been evaluated to establish the optimum zone size of applicability. Planar, cylindrical and spherical interface geometry, and finite, singly infinite, and doubly infinite systems are treated. Two solutions are presented for each geometry, one well suited to short diffusion times, and one to long times. The effect of zone-size on the convergence of these solutions is discussed. A generalized form of the diffusion solution for doubly infinite systems is proposed.

Periodic Time-Domain Nonlocal Nonreflecting Boundary Conditions for Duct Acoustics

NASA Technical Reports Server (NTRS)

Watson, Willie R.; Zorumski, William E.

1996-01-01

Periodic time-domain boundary conditions are formulated for direct numerical simulation of acoustic waves in ducts without flow. Well-developed frequency-domain boundary conditions are transformed into the time domain. The formulation is presented here in one space dimension and time; however, this formulation has an advantage in that its extension to variable-area, higher dimensional, and acoustically treated ducts is rigorous and straightforward. The boundary condition simulates a nonreflecting wave field in an infinite uniform duct and is implemented by impulse-response operators that are applied at the boundary of the computational domain. These operators are generated by convolution integrals of the corresponding frequency-domain operators. The acoustic solution is obtained by advancing the Euler equations to a periodic state with the MacCormack scheme. The MacCormack scheme utilizes the boundary condition to limit the computational space and preserve the radiation boundary condition. The success of the boundary condition is attributed to the fact that it is nonreflecting to periodic acoustic waves. In addition, transient waves can pass rapidly out of the solution domain. The boundary condition is tested for a pure tone and a multitone source in a linear setting. The effects of various initial conditions are assessed. Computational solutions with the boundary condition are consistent with the known solutions for nonreflecting wave fields in an infinite uniform duct.

Environmental Fate and Biological Consequences of Chemicals Related to Air Force Activities

DTIC Science & Technology

1982-09-01

milliliters of a 10% solution over a 78.5-square centimeter surface. Sample treated cores were tested under laboratory conditions and in field studies and using...natural weather conditions for comparative tests. No Sig- nificant differences were noted between field and laboratory conditions . Biological...JP-4- and JP-5-dosed cores initially show a stressed condition as indicated by an increased rate in CO2 produc- tion followed by a rate of CO2

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

Geochemical Modeling of Reactions and Partitioning of Trace Metals and Radionuclides during Titration of Contaminated Acidic Sediments

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

Zhang, Fan; Parker, Jack C.; Luo, Wensui

2008-01-01

Many geochemical reactions that control aqueous metal concentrations are directly affected by solution pH. However, changes in solution pH are strongly buffered by various aqueous phase and solid phase precipitation/dissolution and adsorption/desorption reactions. The ability to predict acid-base behavior of the soil-solution system is thus critical to predict metal transport under variable pH conditions. This study was undertaken to develop a practical generic geochemical modeling approach to predict aqueous and solid phase concentrations of metals and anions during conditions of acid or base additions. The method of Spalding and Spalding was utilized to model soil buffer capacity and pH-dependent cationmore » exchange capacity by treating aquifer solids as a polyprotic acid. To simulate the dynamic and pH-dependent anion exchange capacity, the aquifer solids were simultaneously treated as a polyprotic base controlled by mineral precipitation/dissolution reactions. An equilibrium reaction model that describes aqueous complexation, precipitation, sorption and soil buffering with pH-dependent ion exchange was developed using HydroGeoChem v5.0 (HGC5). Comparison of model results with experimental titration data of pH, Al, Ca, Mg, Sr, Mn, Ni, Co, and SO{sub 4}{sup 2-} for contaminated sediments indicated close agreement, suggesting that the model could potentially be used to predict the acid-base behavior of the sediment-solution system under variable pH conditions.« less

Assessment of Fenton's reagent and ozonation as pre-treatments for increasing the biodegradability of aqueous diethanolamine solutions from an oil refinery gas sweetening process.

PubMed

Durán-Moreno, A; García-González, S A; Gutiérrez-Lara, M R; Rigas, F; Ramírez-Zamora, R M

2011-02-28

The aim of this work was to evaluate the efficiency of three chemical oxidation processes for increasing the biodegradability of aqueous diethanolamine solutions (aqueous DEA solutions), to be used as pre-treatments before a biological process. The raw aqueous DEA solution, sourced from a sour gas sweetening plant at a Mexican oil refinery, was first characterized by standardized physico-chemical methods. Then experiments were conducted on diluted aqueous DEA solutions to test the effects of Fenton's reagent, ozone and ozone-hydrogen peroxide on the removal of some physicochemical parameters of these solutions. Lastly, biodegradability tests based on Dissolved Organic Carbon Die Away OECD301-A, were carried out on a dilution of the raw aqueous DEA solution and on the treated aqueous DEA solutions, produced by applying the best experimental conditions determined during the aforementioned oxidation tests. Experimental results showed that for aqueous DEA solutions treated with Fenton's reagent, the best degradation rate (70%) was obtained at pH 2.8, with Fe(2+) and H(2)O(2) at doses of 1000 and 10,000 mg/L respectively. In the ozone process, the best degradation (60%) was observed in aqueous DEA solution (100 mg COD/L), using 100 mg O(3)/L at pH 5. In the ozone-hydrogen peroxide process, no COD or DOC removals were observed. The diluted spent diethanolamine solution showed its greatest increase in biodegradability after a reaction period of 28 days when treated with Fenton's reagent, but after only 15 days in the case of ozonation. Copyright © 2011 Elsevier B.V. All rights reserved.

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

Soares Azevedo e Silva, Paulo Ricardo, E-mail: paulori@alunos.eel.usp.br; Baldan, Renato, E-mail: renato@ppgem.eel.usp.br; Nunes, Carlos Angelo, E-mail: cnunes@demar.eel.usp.br

MAR-M247 superalloy has excellent mechanical properties and good oxidation resistance at elevated temperatures. Niobium is an element known as {gamma} Prime phase hardener in nickel-based superalloys, besides promoting homogeneous distribution of MC carbides. This work is inserted in a project that aims to evaluate the total replacement of tantalum by niobium atoms in MAR-M247 superalloy (10.2 Co, 10.2 W, 8.5Cr, 5.6 Al, 1.6 Nb, 1.4 Hf, 1.1 Ti, 0.7 Mo, 0.15 C, 0.06 Zr, 0.015 B, Ni balance-wt.%). Based on microstructural characterizations (SEM and FEG-SEM, both with EDS) of the as-cast material and heat-treated materials as well as utilizing Thermocalcmore » simulations and experiments of differential thermal analysis (DTA), heat-treatment at 1260 Degree-Sign C for 8 h was chosen as an ideal condition for the solution of Nb-modified MAR-M247 superalloy. The hardness of as-cast and ideally solution treated materials was 390 {+-} 14 HV and 415 {+-} 6 HV, respectively. - Highlights: Black-Right-Pointing-Pointer DTA and microstructure of MAR-M247(Nb) showed a good agreement with Thermocalc. Black-Right-Pointing-Pointer An ideal condition for solution heat-treatment of MAR-M247(Nb) is 1260 Degree-Sign C for 8 h. Black-Right-Pointing-Pointer It was an observed evidence of incipient melting in samples heat-treated at 1280 Degree-Sign C.« less

Electrochemistry at a Metal Nanoparticle on a Tunneling Film: A Steady-State Model of Current Densities at a Tunneling Ultramicroelectrode.

PubMed

Hill, Caleb M; Kim, Jiyeon; Bard, Allen J

2015-09-09

Here, a new methodology is proposed for treating electrochemical current densities in metal-insulator-metal nanoparticle (M-I-MNP) systems. The described model provides broad, practical insights about MNP-mediated electron transfer to redox species in solution, where electron transfer from the underlying electrode to a MNP via tunneling and heterogeneous electron transfer from the MNP to redox species in solution are treated as sequential steps. Tunneling is treated through an adaptation of the Simmons model of tunneling in metal-insulator-metal structures, and explicit equations are provided for tunneling currents, which demonstrate the effect of various experimental parameters, such as insulator thickness and MNP size. Overall, a general approach is demonstrated for determining experimental conditions where tunneling will have a measurable impact on the electrochemistry of M-I-MNP systems.

Anti-inflammatory activity of nanocrystalline silver-derived solutions in porcine contact dermatitis

PubMed Central

2010-01-01

Background Nanocrystalline silver dressings have anti-inflammatory activity, unlike solutions containing Ag+ only, which may be due to dissolution of multiple silver species. These dressings can only be used to treat surfaces. Thus, silver-containing solutions with nanocrystalline silver properties could be valuable for treating hard-to-dress surfaces and inflammatory conditions of the lungs and bowels. This study tested nanocrystalline silver-derived solutions for anti-inflammatory activity. Methods Inflammation was induced on porcine backs using dinitrochlorobenzene. Negative and positive controls were treated with distilled water. Experimental groups were treated with solutions generated by dissolving nanocrystalline silver in distilled water adjusted to starting pHs of 4 (using CO2), 5.6 (as is), 7, and 9 (using Ca(OH)2). Solution samples were analyzed for total silver. Daily imaging, biopsying, erythema and oedema scoring, and treatments were performed for three days. Biopsies were processed for histology, immunohistochemistry (for IL-4, IL-8, IL-10, TNF-α, EGF, KGF, KGF-2, and apoptotic cells), and zymography (MMP-2 and -9). One-way ANOVAs with Tukey-Kramer post tests were used for statistical analyses. Results Animals treated with pH 7 and 9 solutions showed clear visual improvements. pH 9 solutions resulted in the most significant reductions in erythema and oedema scores. pH 4 and 7 solutions also reduced oedema scores. Histologically, all treatment groups demonstrated enhanced re-epithelialisation, with decreased inflammation. At 24 h, pMMP-2 expression was significantly lowered with pH 5.6 and 9 treatments, as was aMMP-2 expression with pH 9 treatments. In general, treatment with silver-containing solutions resulted in decreased TNF-α and IL-8 expression, with increased IL-4, EGF, KGF, and KGF-2 expression. At 24 h, apoptotic cells were detected mostly in the dermis with pH 4 and 9 treatments, nowhere with pH 5.6, and in both the epidermis and dermis with pH 7. Solution anti-inflammatory activity did not correlate with total silver content, as pH 4 solutions contained significantly more silver than all others. Conclusions Nanocrystalline silver-derived solutions appear to have anti-inflammatory/pro-healing activity, particularly with a starting pH of 9. Solutions generated differently may have varying concentrations of different silver species, only some of which are anti-inflammatory. Nanocrystalline silver-derived solutions show promise for a variety of anti-inflammatory treatment applications. PMID:20170497

Microstructural Evolution and Mechanical Properties of Simulated Heat-Affected Zones in Cast Precipitation-Hardened Stainless Steels 17-4 and 13-8+Mo

NASA Astrophysics Data System (ADS)

Hamlin, Robert J.; DuPont, John N.

2017-01-01

Cast precipitation-hardened (PH) stainless steels 17-4 and 13-8+Mo are used in applications that require a combination of high strength and moderate corrosion resistance. Many such applications require fabrication and/or casting repair by fusion welding. The purpose of this work is to develop an understanding of microstructural evolution and resultant mechanical properties of these materials when subjected to weld thermal cycles. Samples of each material were subjected to heat-affected zone (HAZ) thermal cycles in the solution-treated and aged condition (S-A-W condition) and solution-treated condition with a postweld thermal cycle age (S-W-A condition). Dilatometry was used to establish the onset of various phase transformation temperatures. Light optical microscopy (LOM), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS) were used to characterize the microstructures, and comparisons were made to gas metal arc welds that were heat treated in the same conditions. Tensile testing was also performed. MatCalc thermodynamic and kinetic modeling software was used to predict the evolution of copper (Cu)-rich body center cubic precipitates in 17-4 and β-NiAl precipitates in 13-8+Mo. The yield strength was lower in the simulated HAZ samples of both materials prepared in the S-A-W condition when compared to their respective base metals. Samples prepared in the S-W-A condition had higher and more uniform yield strengths for both materials. Significant changes were observed in the matrix microstructure of various HAZ regions depending on the peak temperature, and these microstructural changes were interpreted with the aid of dilatometry results, LOM, SEM, and EDS. Despite these significant changes to the matrix microstructure, the changes in mechanical properties appear to be governed primarily by the precipitation behavior. The decrease in strength in the HAZ samples prepared in the S-A-W condition was attributed to the dissolution of precipitates, which was supported by the MatCalc modeling results. MatCalc modeling results for samples in the S-W-A condition predicted uniform size of precipitates across all regions of the HAZ, and these predictions were supported by the observed trends in mechanical properties. Cross-weld tensile tests performed on GMA welds showed the same trends in mechanical behavior as the simulated HAZ samples. Welding in the S-W-A condition resulted in over 90 pct retention in yield strength when compared to base metal strengths. These findings indicate that welding these PH stainless steels in the solution-treated condition and using a postweld age will provide better and more uniform mechanical properties in the HAZ that are more consistent with the base metal properties.

Basics of Sterile Compounding: Ophthalmic Preparations, Part 2: Suspensions and Ointments.

PubMed

Allen, Loyd V

2016-01-01

Ophthalmic preparations are used to treat allergies, bacterial and viral infections, glaucoma, and numerous other eye conditions. When the eye's natural defensive mechanisms are compromised or overcome, an ophthalmic preparation, in a solution, suspension, or ointment form, may be indicated, with solutions being the most common form used to deliver a drug to the eye. This article discusses ophthalmic suspensions and ointments and represents part 2 of a 2-part article, the first of which discussed ophthalmic solutions. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Geometric scaling behavior of the scattering amplitude for DIS with nuclei

NASA Astrophysics Data System (ADS)

Kormilitzin, Andrey; Levin, Eugene; Tapia, Sebastian

2011-12-01

The main question, that we answer in this paper, is whether the initial condition can influence on the geometric scaling behavior of the amplitude for DIS at high energy. We re-write the non-linear Balitsky-Kovchegov equation in the form which is useful for treating the interaction with nuclei. Using the simplified BFKL kernel, we find the analytical solution to this equation with the initial condition given by the McLerran-Venugopalan formula. This solution does not show the geometric scaling behavior of the amplitude deeply in the saturation region. On the other hand, the BFKL Pomeron calculus with the initial condition at x=1/mR given by the solution to Balitsky-Kovchegov equation, leads to the geometric scaling behavior. The McLerran-Venugopalan formula is the natural initial condition for the Color Glass Condensate (CGC) approach. Therefore, our result gives a possibility to check experimentally which approach: CGC or BFKL Pomeron calculus, is more satisfactory.

Evaluation of Enzymatically Modified Soy Protein Isolate Film Forming Solution and Film at Different Manufacturing Conditions.

PubMed

Mohammad Zadeh, Elham; O'Keefe, Sean F; Kim, Young-Teck; Cho, Jin-Hun

2018-04-01

The effects of transglutaminase on soy protein isolate (SPI) film forming solution and films were investigated by rheological behavior and physicochemical properties based on different manufacturing conditions (enzyme treatments, enzyme incubation times, and protein denaturation temperatures). Enzymatic crosslinking reaction and changes in molecular weight distribution were confirmed by viscosity measurement and SDS-PAGE, respectively, compared to 2 controls: the nonenzyme treated and the deactivated enzyme treated. Films treated with both the enzyme and the deactivated enzyme showed significant increase in tensile strength (TS), percent elongation (%E), and initial contact angle of films compared to the nonenzyme control film due to the bulk stabilizers in the commercial enzyme. Water absorption property, protein solubility, Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopy revealed that enzyme treated SPI film matrix in the molecular structure level, resulted in the changes in physicochemical properties. Based on our observation, the enzymatic treatment at appropriate conditions is a practical and feasible way to control the physical properties of protein based biopolymeric film for many different scientific and industrial areas. Enzymes can make bridges selectively among different amino acids in the structure of protein matrix. Therefore, protein network is changed after enzyme treatment. The behavior of biopolymeric materials is dependent on the network structure to be suitable in different applications such as bioplastics applied in food and pharmaceutical products. In the current research, transglutaminase, as an enzyme, applied in soy protein matrix in different types of forms, activated and deactivated, and different preparation conditions to investigate its effects on different properties of the new bioplastic film. © 2018 Institute of Food Technologists®.

Studies on the treatment of urine by the biological purification-UV photocatalytic oxidation

NASA Astrophysics Data System (ADS)

Liu, Ch. Ch; Liu, R. D.; Liu, X. S.; Chen, M.; Bian, Z. L.; Hu, J. Ch.

The water-consuming amount in a long-term astro-navigation is large In order to reduce the burden of water supply from Earth ground the space station needs to resolve the problems of water supply For this reason the recovery and regeneration of urine solution of spacemen and its utilization possess a key importance Many investigations on this aspect have been reported Our research based on biological absorption-purification-UV photocatalytic oxidation techniques with a relevant treating equipment that for a comprehensive treatment to fresh urine of spacemen has been created In this equipment the urine solution was used as the nutrient solution for the biological parts in ecological life ensurant system after absorbing the nutrient it was decomposed metabolized and purified in some distance and created a favorable condition for the follow-up oxidation treatment by UV-Photocatalytic Oxidation After these two processes the treated urine solution reached the GB5749-85 standard of water quality

PROCESS FOR RECOVERY OF URANIUM AND VANADIUM FROM CARBONATE SOLUTIONS BY REDUCTION-PRECIPITATION

DOEpatents

Ellis, D.A.; Lindblom, R.O.

1957-09-24

A process employing carbonate leaching of ores and an advantageous methcd of recovering the uranium and vanadium from the leach solution is described. The uranium and vanadium can be precipitated from carbonate leach solutions by reaction with sodium amalgam leaving the leach solution in such a condition that it is economical to replenish for recycling. Such a carbonate leach solution is treated with a dilute sodium amalgam having a sodium concentration within a range of about 0.01 to 0.5% of sodium. Efficiency of the treatment is dependent on at least three additional factors, intimacy of contact of the amalgam with the leach solution, rate of addition of the amalgam and exclusion of oxygen (air).

Spatial homogenization methods for pin-by-pin neutron transport calculations

NASA Astrophysics Data System (ADS)

Kozlowski, Tomasz

For practical reactor core applications low-order transport approximations such as SP3 have been shown to provide sufficient accuracy for both static and transient calculations with considerably less computational expense than the discrete ordinate or the full spherical harmonics methods. These methods have been applied in several core simulators where homogenization was performed at the level of the pin cell. One of the principal problems has been to recover the error introduced by pin-cell homogenization. Two basic approaches to treat pin-cell homogenization error have been proposed: Superhomogenization (SPH) factors and Pin-Cell Discontinuity Factors (PDF). These methods are based on well established Equivalence Theory and Generalized Equivalence Theory to generate appropriate group constants. These methods are able to treat all sources of error together, allowing even few-group diffusion with one mesh per cell to reproduce the reference solution. A detailed investigation and consistent comparison of both homogenization techniques showed potential of PDF approach to improve accuracy of core calculation, but also reveal its limitation. In principle, the method is applicable only for the boundary conditions at which it was created, i.e. for boundary conditions considered during the homogenization process---normally zero current. Therefore, there exists a need to improve this method, making it more general and environment independent. The goal of proposed general homogenization technique is to create a function that is able to correctly predict the appropriate correction factor with only homogeneous information available, i.e. a function based on heterogeneous solution that could approximate PDFs using homogeneous solution. It has been shown that the PDF can be well approximated by least-square polynomial fit of non-dimensional heterogeneous solution and later used for PDF prediction using homogeneous solution. This shows a promise for PDF prediction for off-reference conditions, such as during reactor transients which provide conditions that can not typically be anticipated a priori.

Wall interference and boundary simulation in a transonic wind tunnel with a discretely slotted test section

NASA Technical Reports Server (NTRS)

Al-Saadi, Jassim A.

1993-01-01

A computational simulation of a transonic wind tunnel test section with longitudinally slotted walls is developed and described herein. The nonlinear slot model includes dynamic pressure effects and a plenum pressure constraint, and each slot is treated individually. The solution is performed using a finite-difference method that solves an extended transonic small disturbance equation. The walls serve as the outer boundary conditions in the relaxation technique, and an interaction procedure is used at the slotted walls. Measured boundary pressures are not required to establish the wall conditions but are currently used to assess the accuracy of the simulation. This method can also calculate a free-air solution as well as solutions that employ the classical homogeneous wall conditions. The simulation is used to examine two commercial transport aircraft models at a supercritical Mach number for zero-lift and cruise conditions. Good agreement between measured and calculated wall pressures is obtained for the model geometries and flow conditions examined herein. Some localized disagreement is noted, which is attributed to improper simulation of viscous effects in the slots.

Study of the IGA/SCC behavior of Alloy 600 and 690 in high temperature solutions

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

Tsujikawa, S.; Yashima, S.; Ohnishi, K.

1995-09-01

IGA/SCC of Alloy 600 steam generator (SG) tubes in the secondary side has been recognized as a matter of great concern for PWRs. IGA/SCC behavior of Alloy 600 and 690 in high temperature solutions were studied using CERT method under potentiostatic conditions. The IGA/SCC susceptible regions were investigated as the function of pH and electrode potential. To understand the cause of IGA/SCC, the electrochemical measurements and surface film analysis were also performed in acidic and alkaline solutions. To verify the results of CERT test, the long term model boiler tests were also carried out. Thermally treated Alloy 690 showed highermore » IGA/SCC resistance than Alloy 600 under both acid and alkaline conditions.« less

Influence of Oxidation Treatments and Surface Finishing on the Electrochemical Behavior of Ni-20Cr HVOF Coatings

NASA Astrophysics Data System (ADS)

Ruiz-Luna, H.; Porcayo-Calderon, J.; Alvarado-Orozco, J. M.; Mora-García, A. G.; Martinez-Gomez, L.; Trápaga-Martínez, L. G.; Muñoz-Saldaña, J.

2017-12-01

The low-temperature electrochemical behavior of HVOF Ni-20Cr coatings was assessed. The coatings were evaluated in different conditions including as-sprayed, as-ground, and heat-treated in air and argon atmospheres. A detailed analysis of the coatings was carried out by means of XRD, SEM, and EPMA, prior and after the corrosion test. The corrosion rate was analyzed in a NaCl solution saturated with CO2. Results demonstrate that the use of a low-oxygen partial pressure favors the formation of a Cr2O3 layer on the surface of the coatings. According to the electrochemical results, the lower corrosion rates were obtained for the heat-treated coatings irrespective of the surface finishing, being the ground and argon heat-treated condition that shows the best corrosion performance. This behavior is due to the synergistic effect of the low-pressure heat treatment and the grinding processes. The grinding promotes a more homogeneous reaction area without surface heterogeneities such as voids, and the pre-oxidation treatment decreases the porosity content of the coating and also allows the growing of a Cr-rich oxide scale which acts as a barrier against the ions of the aqueous solution.

Plasma expansion into a vacuum with an arbitrarily oriented external magnetic field

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

García-Rubio, F., E-mail: fernando.garcia.rubio@upm.es; Sanz, J.; Ruocco, A.

2016-01-15

Plasma expansion into a vacuum with an external magnetic field is studied under the ideal magnetohydrodynamic hypothesis. The inclination of the magnetic field with respect to the expansion direction is arbitrary, and both the perpendicular and the oblique cases are separately analyzed. A self-similar solution satisfying the boundary conditions is obtained. The interface with the vacuum is treated as a fluid surface, and jump conditions concerning the momentum conservation are imposed. The effect of the intensity of the magnetic field and its inclination is thoroughly studied, and the consistency of the solution for small and large inclinations is investigated.

Improved distorted wave theory with the localized virial conditions

NASA Astrophysics Data System (ADS)

Hahn, Y. K.; Zerrad, E.

2009-12-01

The distorted wave theory is operationally improved to treat the full collision amplitude, such that the corrections to the distorted wave Born amplitude can be systematically calculated. The localized virial conditions provide the tools necessary to test the quality of successive approximations at each stage and to optimize the solution. The details of the theoretical procedure are explained in concrete terms using a collisional ionization model and variational trial functions. For the first time, adjustable parameters associated with an approximate scattering solution can be fully determined by the theory. A small number of linear parameters are introduced to examine the convergence property and the effectiveness of the new approach.

SONOCHEMICAL DECHLORINATION OF HAZARDOUS WASTES IN AQUEOUS SYSTEMS. (R825513C004)

EPA Science Inventory

Physical processes resulting from ultrasonication of aqueous solutions and suspensions produce extreme conditions that can affect the chemistry of dissolved and suspended chemicals. The purpose of this work was to explore the use of sonochemistry in treating chlorinated chemic...

Microstructure and Properties of a High-Strength Cu-Ni-Si-Co-Zr Alloy

NASA Astrophysics Data System (ADS)

Chenna Krishna, S.; Srinath, J.; Jha, Abhay K.; Pant, Bhanu; Sharma, S. C.; George, Koshy M.

2013-07-01

A high-strength Cu-Ni-Si alloy was developed with the additions of Co and Zr. The aging curve for the alloy was generated using hardness. Electron microscopy studies were conducted to analyze the phases in the alloy. Two types of phases, one of copper matrix and the other of Ni-Si-Co-Zr intermetallic phase, could be identified using scanning electron microscopy. Transmission electron microscopy studies confirmed the presence of two types of precipitates in solution-treated and aged (STA) condition, i.e., Ni2Si and Co2Si. Mechanical properties and electrical conductivity were evaluated in solution-treated (ST) and STA conditions. Aging of the ST samples at 500 °C for 3 h has shown an increase of 72 and 15% in yield strength (YS) and electrical conductivity, respectively. This increase in YS and conductivity on aging is primarily attributed to the formation of fine Ni2Si and Co2Si precipitates.

Synthesis of three commercial products from Bayer electrofilter powders.

PubMed

Ayala, Julia; Fernández, Begoña; Sancho, José Pedro; García, Purificación

2010-06-15

Electrofilter powders, a by-product of the Bayer process for the production of alumina from bauxite, were leached with sulphuric acid to dissolve gibbsite and transition aluminas, thus obtaining a commercial aluminium sulphate solution and a solid residue. This residue is treated again under more drastic conditions with sulphuric acidic in a furnace at a higher temperature, is then leached with water and filtered, a small amount of solid remaining (alpha-alumina). The liquid is a highly acidic aluminium sulphate solution which does not fulfil commercial grade specifications; the liquor is accordingly treated with potassium hydroxide or ammonium hydroxide to obtain potassium or ammonium alum. Experimental tests were conducted to investigate the synthesis of alum by crystallization. The effects on alum formation of various operating conditions, including the amount of potassium or ammonium hydroxide, temperature and seed alum dosage, were examined. The crystallization process was found to be quite effective in obtaining alum. Copyright 2010 Elsevier B.V. All rights reserved.

Effect of outdoor exposure at ambient and elevated temperatures on fatigue life of Ti-6Al-4V titanium alloy sheet in the annealed and the solution treated and aged condition

NASA Technical Reports Server (NTRS)

Phillips, E. P.

1974-01-01

Specimens of Ti-6Al-4V titanium alloy sheet in the annealed and the solution-treated and aged heat-treatment condition were exposed outdoors at ambient and 560 K (550 F) temperatures to determine the effect of outdoor exposure on fatigue life. Effects of exposure were determined by comparing fatigue lives of exposed specimens to those of unexpected specimens. Two procedures for fatigue testing the exposed specimens were evaluated: (1) fatigue tests conducted outdoors by applying 1200 load cycles per week until failure occurred and (2) conventional fatigue tests (continuous cycling until failure occurred) conducted indoors after outdoor exposure under static load. The exposure period ranged from 9 to 28 months for the outdoor fatigue-test group and was 24 months for the static-load group. All fatigue tests were constant-amplitude bending of specimens containing a drilled hole (stress concentration factor of 1.6). The results of the tests indicate that the fatigue lives of solution-treated and aged specimens were significantly reduced by the outdoor exposure at 560 K but not by the exposure at ambient temperature. Fatigue lives of the annealed specimens were essentially unaffected by the outdoor exposure at either temperature. The two test procedures - outdoor fatigue test and indoor fatigue test after outdoor exposure - led to the same conclusions about exposure effects.

Corrosion in MDEA sour gas treating plants: Correlation between laboratory testing and field experience

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

Bich, N.N.; Vacha, F.; Schubert, R.

1996-08-01

Corrosion in MDEA sour gas treating systems operating in severely loaded conditions is investigated using both laboratory data and actual gas plant experience. Effects of acid gas loading, flow turbulence, solution quality, temperature, etc. on corrosion are being studied. Preliminary results indicated severe corrosion of several mm/y would occur if acid gas loading, circulation rate and level of suspended solids are all high. A mitigation strategy based on operating envelopes is formulated.

Successful management of angiolymphoid hyperplasia with eosinophilia in a split-face trial of topical tacrolimus and timolol solution.

PubMed

Chacon, Anna; Mercer, Jessica

2016-08-01

Angiolymphoid hyperplasia with eosinophilia (ALHE) is an uncommon, benign condition characterized by multiple benign angiomatous nodules or plaques. Cutaneous lesions can be painful, pruritic, pulsatile, or potentially disfiguring resulting in significant morbidity. ALHE is a pathologic diagnosis featuring proliferations of capillary-sized vessels with epithelioid endothelial cells surrounded by larger, thick-walled vessels and accompanying eosinophils and lymphocytes. Surgery is generally required, however the skin lesions often recur after excision. ALHE is notoriously difficult to treat and many physicians would prefer a non-invasive treatment of choice. We report a case of ALHE that was successfully treated with the novel use of topical tacrolimus in a split-face trial with topical timolol solution.

Exact time-dependent nonlinear dispersive wave solutions in compressible magnetized plasmas exhibiting collapse.

PubMed

Chakrabarti, Nikhil; Maity, Chandan; Schamel, Hans

2011-04-08

Compressional waves in a magnetized plasma of arbitrary resistivity are treated with the lagrangian fluid approach. An exact nonlinear solution with a nontrivial space and time dependence is obtained with boundary conditions as in Harris' current sheet. The solution shows competition among hydrodynamic convection, magnetic field diffusion, and dispersion. This results in a collapse of density and the magnetic field in the absence of dispersion. The dispersion effects arrest the collapse of density but not of the magnetic field. A possible application is in the early stage of magnetic star formation.

Purification of inkjet ink from water using liquid phase, electric discharge polymerization and cellulosic membrane filtration.

PubMed

Jordan, Alexander T; Hsieh, Jeffery S; Lee, Daniel T

2013-01-01

A method to separate inkjet ink from water was developed using a liquid phase, electric discharge process. The liquid phase, electric discharge process with filtration or sedimentation was shown to remove 97% of inkjet ink from solutions containing between 0.1-0.8 g/L and was consistent over a range of treatment conditions. Additionally, particle size analysis of treated allyl alcohol and treated propanol confirmed the electric discharge treatment has a polymerization mechanism, and small molecule analysis of treated methanol using gas chromatography and mass spectroscopy confirmed the mechanism was free radical initiated polymerization.

Removal of anionic dye Congo red from aqueous solution by raw pine and acid-treated pine cone powder as adsorbent: equilibrium, thermodynamic, kinetics, mechanism and process design.

PubMed

Dawood, Sara; Sen, Tushar Kanti

2012-04-15

Pine cone a natural, low-cost agricultural by-product in Australia has been studied for its potential application as an adsorbent in its raw and hydrochloric acid modified form. Surface study of pine cone and treated pine cone was investigated using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The modification process leads to increases in the specific surface area and decreases mean particle sizes of acid-treated pine cone when compared to raw pine cone biomass. Batch adsorption experiments were performed to remove anionic dye Congo red from aqueous solution. It was found that the extent of Congo red adsorption by both raw pine cone biomass and acid-treated biomass increased with initial dye concentration, contact time, temperature but decreased with increasing solution pH and amount of adsorbent of the system. Overall, kinetic studies showed that the dye adsorption process followed pseudo-second-order kinetics based on pseudo-first-order and intra-particle diffusion models. The different kinetic parameters including rate constant, half-adsorption time, and diffusion coefficient were determined at different physico-chemical conditions. Equilibrium data were best represented by Freundlich isotherm model among Langmuir and Freundlich adsorption isotherm models. It was observed that the adsorption was pH dependent and the maximum adsorption of 32.65 mg/g occurred at pH of 3.55 for an initial dye concentration of 20 ppm by raw pine cone, whereas for acid-treated pine cone the maximum adsorption of 40.19 mg/g for the same experimental conditions. Freundlich constant 'n' also indicated favourable adsorption. Thermodynamic parameters such as ∆G(0), ∆H(0), and ∆S(0) were calculated. A single-stage batch absorber design for the Congo red adsorption onto pine cone biomass also presented based on the Freundlich isotherm model equation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Numerical Study of Periodic Traveling Wave Solutions for the Predator-Prey Model with Landscape Features

NASA Astrophysics Data System (ADS)

Yun, Ana; Shin, Jaemin; Li, Yibao; Lee, Seunggyu; Kim, Junseok

We numerically investigate periodic traveling wave solutions for a diffusive predator-prey system with landscape features. The landscape features are modeled through the homogeneous Dirichlet boundary condition which is imposed at the edge of the obstacle domain. To effectively treat the Dirichlet boundary condition, we employ a robust and accurate numerical technique by using a boundary control function. We also propose a robust algorithm for calculating the numerical periodicity of the traveling wave solution. In numerical experiments, we show that periodic traveling waves which move out and away from the obstacle are effectively generated. We explain the formation of the traveling waves by comparing the wavelengths. The spatial asynchrony has been shown in quantitative detail for various obstacles. Furthermore, we apply our numerical technique to the complicated real landscape features.

40 CFR 265.443 - Design and operating requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... free-drain treated wood drippage, rain and other waters, or solutions of drippage and water or other..., climatic conditions, the stress of installation, and the stress of daily operations, e.g., variable and... or groundwater or surface water at any time during the active life (including the closure period) of...

40 CFR 265.443 - Design and operating requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... free-drain treated wood drippage, rain and other waters, or solutions of drippage and water or other..., climatic conditions, the stress of installation, and the stress of daily operations, e.g., variable and... or groundwater or surface water at any time during the active life (including the closure period) of...

Intrawellbore kinematic and frictional losses in a horizontal well in a bounded confined aquifer

NASA Astrophysics Data System (ADS)

Wang, Quanrong; Zhan, Hongbin

2017-01-01

Horizontal drilling has become an appealing technology for water resource exploration or aquifer remediation in recent decades, due to decreasing operational cost and many technical advantages over vertical wells. However, many previous studies on flow into horizontal wells were based on the Uniform Flux Boundary Condition (UFBC), which does not reflect the physical processes of flow inside the well accurately. In this study, we investigated transient flow into a horizontal well in an anisotropic confined aquifer laterally bounded by two constant-head boundaries. Three types of boundary conditions were employed to treat the horizontal well, including UFBC, Uniform-Head Boundary Condition (UHBC), and Mixed-Type Boundary Condition (MTBC). The MTBC model considered both kinematic and frictional effects inside the horizontal well, in which the kinematic effect referred to the accelerational and fluid-inflow effects. A new solution of UFBC was derived by superimposing the point sink/source solutions along the axis of a horizontal well with a uniform flux distribution. New solutions of UHBC and MTBC were obtained by a hybrid analytical-numerical method, and an iterative method was proposed to determine the well discretization required for achieving sufficiently accurate results. This study showed that the differences among the UFBC, UHBC, and MTBC solutions were obvious near the well screen, decreased with distance from the well, and became negligible near the constant-head boundary. The relationship between the flow rate and the drawdown was nonlinear for the MTBC solution, while it was linear for the UFBC and UHBC solutions.

Sonophotocatalytic degradation of dye C.I. Acid Orange 7 by TiO2 and Ag nanoparticles immobilized on corona pretreated polypropylene non-woven fabric.

PubMed

Marković, Darka; Šaponjić, Zoran; Radoičić, Marija; Radetić, Tamara; Vodnik, Vesna; Potkonjak, Branislav; Radetić, Maja

2015-05-01

This study discusses the possibility of using corona pre-treated polypropylene (PP) non-woven fabric as a support for immobilization of colloidal TiO2 and Ag nanoparticles in order to remove dye C.I. Acid Orange 7 from aqueous solution. Dye removal efficiency by sonocatalysis, photocatalysis and sonophotocatalysis was evaluated on corona pre-treated fabric loaded with TiO2 nanoparticles, corona pre-treated fabric double loaded with TiO2 nanoparticles and corona pre-treated fabrics loaded with TiO2 nanoparticles before and after deposition of Ag nanoparticles. In addition, the stability of PP non-woven fabric during these processes was investigated. The substrates were characterized by SEM, EDX and AAS analyses. The change of the dye concentration was evaluated by UV-VIS spectrophotometry. Unlike sonocatalysis and photocatalysis, complete dye removal from both solution and non-woven fabric was obtained already after 240-270 min of sonophotocatalysis. Corona pre-treated PP non-woven fabric loaded with Ag nanoparticles prior to deposition of TiO2 nanoparticles provided excellent degradation efficiency and superior reusability. Sonophotocatalytic degradation of dye in the presence of all investigated samples was the most prominent in acidic conditions. Although this nanocomposite system ensured fast discoloration of dye solution, TOC values of water measured after sonophotocatalysis were not satisfactory because of PP degradation. Therefore, it is suggested to include TOC evaluation in each case study where different supports for TiO2 nanoparticles are used since these nanoparticles may guarantee the dye removal from solution but the stability of support could be problematic causing even more serious environmental impact. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of Heat Treatment on the Discharge Behavior of Mg-6wt.%Al-1wt.%Sn Alloy as Anode For Magnesium-Air Batteries

NASA Astrophysics Data System (ADS)

Xiong, Hanqing; Zhu, Hualong; Luo, Jie; Yu, Kun; Shi, Chunli; Fang, Hongjie; Zhang, Yu

2017-05-01

Mg-6wt.%Al-1wt.%Sn alloys under different conditions are prepared. Primary magnesium-air batteries are assembled using such experimental Mg-Al-Sn alloys as anodes. The discharge behaviors of different alloys are investigated in 3.5 wt.% NaCl solution. The results show that the solution treatment can facilitate the homogeneous distribution of alloy elements and reduce the accumulation of discharge products. The magnesium-air battery based on the solution-treated Mg-Al-Sn anode presents higher operating voltage and more stable discharge process than those on the as-cast and the aged ones. Although the solution treatment cannot effectively improve the capacity density and the anodic efficiency of the experimental Mg-Al-Sn alloy, it is an effective approach to increasing the power and the energy density during discharge process. Especially at the applied current density of 30 mA cm-2 for 5 h, the solution-treated anode supplies 1.212 V average operating voltage, the anode energy density reaches 1527.2 mWhg-1, while the cast one is 1481.3 mWhg-1 and the aged one is 1478.8 mWhg-1.

Parathion degradation and toxicity reduction in solar photocatalysis and photolysis.

PubMed

Zoh, K D; Kim, T S; Kim, J G; Choi, K; Yi, S M

2006-01-01

The solar photocatalytic degradation of methyl parathion was investigated using a circulating TiO2/solar light reactor. Under solar photocatalysis condition, parathion was more effectively degraded than solar photolysis and TiO2-only conditions. With solar photocatalysis, 20 mg/L of parathion was completely degraded within 60 min with a TOC decrease of 63% after 150 min. The main ionic byproducts during photocatalysis recovered from parathion degradation were mainly as NO3-, NO2- and NH4+, 80% of the sulphur as SO4(2-), and 5% of phosphorus as PO4(3-). The organic intermediates 4-nitrophenol and methyl paraoxon were also identified, and these were further degraded in solar photocatalytic condition. Two different bioassays (Vibrio fischeri and Daphnia magna) were used to test the acute toxicity of solutions treated by solar photocatalysis and photolysis. The Microtox test using V. fischeri showed that the toxicity expressed as EC50 (%) value increased from 5.5% to >82% in solar photocatalysis, indicating that the treated solution is non-toxic, but only increased from 4.9 to 20.5% after 150 min in solar photolysis. The acute toxicity test using D. magna showed that EC50 (%) increased from 0.05 to 1.08% under solar photocatalysis, but only increased to 0.12% after 150 min with solar photolysis, indicating the solution is still toxic. The pattern of toxicity reduction parallels the decrease in TOC and the parathion concentrations.

Wolframite Conversion in Treating a Mixed Wolframite-Scheelite Concentrate by Sulfuric Acid

NASA Astrophysics Data System (ADS)

Shen, Leiting; Li, Xiaobin; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui; Taskinen, Pekka

2017-12-01

Complete wolframite conversion in sulfuric acid is significant for expanding the applicability of the sulfuric acid method for producing ammonium paratungstate. In this paper, the conversion of wolframite in treating a mixed wolframite-scheelite concentrate by sulfuric acid was studied systematically. The results show that the conversion of wolframite in sulfuric acid is more difficult than that of scheelite, requiring rigorous reaction conditions. A solid H2WO4 layer forms on the surfaces of the wolframite particles and becomes denser with increasing H2SO4 concentration, thus hindering the conversion. Furthermore, the difficulty in wolframite conversion can be mainly attributed to the accumulation of Fe2+ (and/or Mn2+) in the H2SO4 solution, which can be solved by reducing Fe2+ (and/or Mn2+) concentration through oxidization and/or a two-stage process. Additionally, the solid converted product of the mixed wolframite-scheelite concentrate has an excellent leachability of tungsten in an aqueous ammonium carbonate solution at ambient temperature, with approximately 99% WO3 recovery. This work presents a route for manufacturing ammonium paratungstate by treating the mixed concentrate in sulfuric acid followed by leaching in ammonium carbonate solution.

Wolframite Conversion in Treating a Mixed Wolframite-Scheelite Concentrate by Sulfuric Acid

NASA Astrophysics Data System (ADS)

Shen, Leiting; Li, Xiaobin; Zhou, Qiusheng; Peng, Zhihong; Liu, Guihua; Qi, Tiangui; Taskinen, Pekka

2018-02-01

Complete wolframite conversion in sulfuric acid is significant for expanding the applicability of the sulfuric acid method for producing ammonium paratungstate. In this paper, the conversion of wolframite in treating a mixed wolframite-scheelite concentrate by sulfuric acid was studied systematically. The results show that the conversion of wolframite in sulfuric acid is more difficult than that of scheelite, requiring rigorous reaction conditions. A solid H2WO4 layer forms on the surfaces of the wolframite particles and becomes denser with increasing H2SO4 concentration, thus hindering the conversion. Furthermore, the difficulty in wolframite conversion can be mainly attributed to the accumulation of Fe2+ (and/or Mn2+) in the H2SO4 solution, which can be solved by reducing Fe2+ (and/or Mn2+) concentration through oxidization and/or a two-stage process. Additionally, the solid converted product of the mixed wolframite-scheelite concentrate has an excellent leachability of tungsten in an aqueous ammonium carbonate solution at ambient temperature, with approximately 99% WO3 recovery. This work presents a route for manufacturing ammonium paratungstate by treating the mixed concentrate in sulfuric acid followed by leaching in ammonium carbonate solution.

Decentralized DC Microgrid Monitoring and Optimization via Primary Control Perturbations

NASA Astrophysics Data System (ADS)

Angjelichinoski, Marko; Scaglione, Anna; Popovski, Petar; Stefanovic, Cedomir

2018-06-01

We treat the emerging power systems with direct current (DC) MicroGrids, characterized with high penetration of power electronic converters. We rely on the power electronics to propose a decentralized solution for autonomous learning of and adaptation to the operating conditions of the DC Mirogrids; the goal is to eliminate the need to rely on an external communication system for such purpose. The solution works within the primary droop control loops and uses only local bus voltage measurements. Each controller is able to estimate (i) the generation capacities of power sources, (ii) the load demands, and (iii) the conductances of the distribution lines. To define a well-conditioned estimation problem, we employ decentralized strategy where the primary droop controllers temporarily switch between operating points in a coordinated manner, following amplitude-modulated training sequences. We study the use of the estimator in a decentralized solution of the Optimal Economic Dispatch problem. The evaluations confirm the usefulness of the proposed solution for autonomous MicroGrid operation.

Time-Accurate, Unstructured-Mesh Navier-Stokes Computations with the Space-Time CESE Method

NASA Technical Reports Server (NTRS)

Chang, Chau-Lyan

2006-01-01

Application of the newly emerged space-time conservation element solution element (CESE) method to compressible Navier-Stokes equations is studied. In contrast to Euler equations solvers, several issues such as boundary conditions, numerical dissipation, and grid stiffness warrant systematic investigations and validations. Non-reflecting boundary conditions applied at the truncated boundary are also investigated from the stand point of acoustic wave propagation. Validations of the numerical solutions are performed by comparing with exact solutions for steady-state as well as time-accurate viscous flow problems. The test cases cover a broad speed regime for problems ranging from acoustic wave propagation to 3D hypersonic configurations. Model problems pertinent to hypersonic configurations demonstrate the effectiveness of the CESE method in treating flows with shocks, unsteady waves, and separations. Good agreement with exact solutions suggests that the space-time CESE method provides a viable alternative for time-accurate Navier-Stokes calculations of a broad range of problems.

The Crystallization of Canavalin as a Function of pH and NaCl Concentration

NASA Technical Reports Server (NTRS)

Forsythe, Elizabeth L.; Gorti, Sridhar; Pusey, Marc L.

2004-01-01

We posed the question of what happens to a protein that is known to grow as an n-mer when it is placed in solution conditions where it is monomeric. The trypsin-treated, or cut, form of the protein canavalin (CCAN) has been shown to nucleate and grow crystals as a trimer from neutral to slightly acidic solutions. Under these conditions the solution is composed almost wholly of trimers. The crystalline protein can be readily dissolved by weakly basic solution, which has been proposed to result in a solution that is monomeric. There are three possible outcomes to an attempt at crystallization of the protein under monomeric (high pH) conditions: 1) we will obtain the same crystals as under trimer conditions, but at different protein concentrations governed by the self association equilibria; 2) we will obtain crystals having a different symmetry, based upon a monomeric growth unit; 3) we will not obtain crystals. Obtaining the first result would be indicative that the solution-phase self-association process is critical to the crystal nucleation and growth process. The second result would be less clear, as it may also reflect a pH-dependent shift in the trimer-trimer molecular interactions. The third result, particularly for experiments in the transition pH's between trimeric and monomeric CCAN, would indicate that the monomer does not crystallize, and that solution phase self association is not part of the crystal nucleation and growth path. Results are presented for crystallization experiments of CCAN over the pH 6.4 to 9.6 range. Fluorescence anisotropy, light scattering, and gel filtration experiments show that the solutions are primarily trimers, with association to form larger species occurring as a function of protein concentration.

Investigation of manifestation of optical properties of butterfly wings with nanoscale zinc oxide incorporation

NASA Astrophysics Data System (ADS)

Aideo, Swati N.; Mohanta, Dambarudhar

2016-10-01

In this work, microstructural and optical characteristics nanoparticles of wings of Tailed Jay (Graphium Agamemnon) butterfly were studied before and after treating it in a precursor solution of zinc acetate and ethanol. We speculate that the butterfly scales are infiltrated with ZnO nanoparticles owing to reduction of Zinc hydroxide under ambient condition. The ZnO butterfly scales so produced were characterised using optical microscopy, UV-Vis reflectance spectroscopy, and electron microscopy etc. From the reflectance spectra, we could see that after treating it in the solution, optical properties vary. We anticipate that this change may be due to the formation of ZnO nanoparticles as well as the loss in periodicity due to the chemical treatments, which could be assessed from the SEM micrographs.

Solutions for Reacting and Nonreacting Viscous Shock Layers with Multicomponent Diffusion and Mass Injection. Ph.D. Thesis - Virginia Polytechnic Inst. and State Univ.

NASA Technical Reports Server (NTRS)

Moss, J. N.

1971-01-01

Numerical solutions are presented for the viscous shocklayer equations where the chemistry is treated as being either frozen, equilibrium, or nonequilibrium. Also the effects of the diffusion model, surface catalyticity, and mass injection on surface transport and flow parameters are considered. The equilibrium calculations for air species using multicomponent: diffusion provide solutions previously unavailable. The viscous shock-layer equations are solved by using an implicit finite-difference scheme. The flow is treated as a mixture of inert and thermally perfect species. Also the flow is assumed to be in vibrational equilibrium. All calculations are for a 45 deg hyperboloid. The flight conditions are those for various altitudes and velocities in the earth's atmosphere. Data are presented showing the effects of the chemical models; diffusion models; surface catalyticity; and mass injection of air, water, and ablation products on heat transfer; skin friction; shock stand-off distance; wall pressure distribution; and tangential velocity, temperature, and species profiles.

General Theory of Aerodynamic Instability and the Mechanism of Flutter

NASA Technical Reports Server (NTRS)

Theodorsen, Theodore

1979-01-01

The aerodynamic forces on an oscillating airfoil or airfoil-aileron combination of three independent degrees of freedom were determined. The problem resolves itself into the solution of certain definite integrals, which were identified as Bessel functions of the first and second kind, and of zero and first order. The theory, based on potential flow and the Kutta condition, is fundamentally equivalent to the conventional wing section theory relating to the steady case. The air forces being known, the mechanism of aerodynamic instability was analyzed. An exact solution, involving potential flow and the adoption of the Kutta condition, was derived. The solution is of a simple form and is expressed by means of an auxiliary parameter k. The flutter velocity, treated as the unknown quantity, was determined as a function of a certain ratio of the frequencies in the separate degrees of freedom for any magnitudes and combinations of the airfoil-aileron parameters.

Photoelectrons in the Quiet Polar Wind

NASA Technical Reports Server (NTRS)

Glocer, A.; Khazanov, G.; Liemohn, M.

2017-01-01

This study presents a newly coupled model capable of treating the superthermal electron population in the global polar wind solution. The model combines the hydrodynamic Polar Wind Outflow Model (PWOM) with the kinetic SuperThermal Electron Transport (STET) code. The resulting PWOM-STET coupled model is described and then used to investigate the role of photoelectrons in the polar wind. We present polar wind results along single stationary field lines under dayside and nightside conditions, as well as the global solution reconstructed from nearly 1000 moving field lines. The model results show significant day-night asymmetries in the polar wind solution owing to the higher ionization and photoelectron fluxes on the dayside compared to the nightside. Field line motion is found to modify this dependence and create global structure by transporting field lines through different conditions of illumination and through the localized effects of Joule heating.

FASOR - A second generation shell of revolution code

NASA Technical Reports Server (NTRS)

Cohen, G. A.

1978-01-01

An integrated computer program entitled Field Analysis of Shells of Revolution (FASOR) currently under development for NASA is described. When completed, this code will treat prebuckling, buckling, initial postbuckling and vibrations under axisymmetric static loads as well as linear response and bifurcation under asymmetric static loads. Although these modes of response are treated by existing programs, FASOR extends the class of problems treated to include general anisotropy and transverse shear deformations of stiffened laminated shells. At the same time, a primary goal is to develop a program which is free of the usual problems of modeling, numerical convergence and ill-conditioning, laborious problem setup, limitations on problem size and interpretation of output. The field method is briefly described, the shell differential equations are cast in a suitable form for solution by this method and essential aspects of the input format are presented. Numerical results are given for both unstiffened and stiffened anisotropic cylindrical shells and compared with previously published analytical solutions.

40 CFR 264.573 - Design and operating requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... treated wood drippage, rain and other waters, or solutions of drippage and water or other wastes to the..., climatic conditions, the stress of daily operations, e.g., variable and moving loads such as vehicle... groundwater or surface water at any time during the active life (including the closure period) of the drip pad...

40 CFR 264.573 - Design and operating requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... treated wood drippage, rain and other waters, or solutions of drippage and water or other wastes to the..., climatic conditions, the stress of daily operations, e.g., variable and moving loads such as vehicle... groundwater or surface water at any time during the active life (including the closure period) of the drip pad...

Combat or Cooperation?

ERIC Educational Resources Information Center

Tate, Thomas F.; Copas, Randall L.

2010-01-01

The best intentioned efforts of adults are often sabotaged by coercive climates of bullying among peers and conflict with adults. The solution is to create cultures where youth cooperate with authority and treat one another with respect. In this article, the authors stress the task of the staff to create a condition in which students see more…

Time-Domain Impedance Boundary Conditions for Computational Aeroacoustics

NASA Technical Reports Server (NTRS)

Tam, Christopher K. W.; Auriault, Laurent

1996-01-01

It is an accepted practice in aeroacoustics to characterize the properties of an acoustically treated surface by a quantity known as impedance. Impedance is a complex quantity. As such, it is designed primarily for frequency-domain analysis. Time-domain boundary conditions that are the equivalent of the frequency-domain impedance boundary condition are proposed. Both single frequency and model broadband time-domain impedance boundary conditions are provided. It is shown that the proposed boundary conditions, together with the linearized Euler equations, form well-posed initial boundary value problems. Unlike ill-posed problems, they are free from spurious instabilities that would render time-marching computational solutions impossible.

PROCESS FOR RECOVERY OF URANIUM VALUES FROM IMPURE SOLUTIONS THEREOF

DOEpatents

Kilner, S.B.

1959-11-01

A process is presented for the recovery of uraninm values from impure solutions which are obtained, for example, by washing residual uranium salt or uranium metal deposits from stainless steel surfaces using an aqueous or certain acidic aqueous solutions. The solutions include uranyl and oxidized iron, chromium, nickel, and copper ions and may contain manganese, zinc, and silver ions. In accordance with one procedure. the uranyl ions are reduced to the uranous state, and the impurity ions are complexed with cyanide under acidic conditions. The solution is then treated with ammonium hydroxide or alkali metal hydroxide to precipitate uranous hydroxide away from the complexed impurity ions in the solution. Alternatively, an excess of alkali metal cyanide is added to the reduced solution until the solution becomes sufficiently alkaline for the uranons hydroxide to precipitate. An essential feature in operating the process is in maintaining the pH of the solution sufficiently acid during the complexing operation to prevent the precipitation of the impurity metal hydroxides.

Dynamics of hydrated mucopolysaccharides in cartilaginous tissues treated by laser radiation

NASA Astrophysics Data System (ADS)

Omelchenko, Alexander I.; Sobol, Emil N.; Ignatieva, Natalia Y.; Lunin, Valerii V.; Jumel, Kornelia; Harding, Stephen E.; Jones, Nicholas

2001-05-01

Dynamic mechanical properties of hydrated mucopolysaccharides have been studied in heated solutions by means of molecular hydrodynamic and acoustic techniques. These experiments model the thermal condition used for laser reshaping of cartilage. It has been shown that elastic modulus and internal friction depends on concentration of chondroitine sulphate in the solution and temperature. Maximum of internal friction was revealed at about 40 degree(s)C that corresponds to temperature of breakdown of hydrophobic bonds. Temperature dependence of internal friction manifests structural changes in polysaccharides molecules under laser heating.

An evaluation of the mobility of pathogen indicators, Escherichia coli and bacteriophage MS-2, in a highly weathered tropical soil under unsaturated conditions

USGS Publications Warehouse

Wong, T.-P.; Byappanahalli, M.; Yoneyama, B.; Ray, C.

2008-01-01

Laboratory column experiments were conducted to study the effects of anionic polyacrylamide (PAM) polymer and surfactant linear alkylbenzene sulfonate (LAS) on the movement of Escherichia coli and the FRNA phage MS-2. The study was designed to evaluate if PAM or PAM + LAS would enhance the mobility of human pathogens in tropical soils under unsaturated conditions. No breakthrough of phage was observed in a 10 cm column after passing 100 pore volumes of solution containing 1 ?? 108 plaque-forming units (PFU)/ml. In later experiments, after passing 10-20 pore volumes of influent containing 1 ?? 108/ml MS-2 or E. coli through 15 cm columns, the soil was sliced and the organisms eluted. Phage moved slightly deeper in the polymer-treated column than in the control column. There was no measurable difference in the movement of E. coli in either polymer-treated or control columns. The properties of the soil (high amounts of metal oxides, kaolinitic clay), unsaturated flow conditions, and relatively high ionic strengths of the leaching solution attributed to significant retention of these indicators. The impacts of PAM and LAS on the mobility of E. coli or MS-2 phage in the chosen soils were not significant. ?? IWA Publishing 2008.

Accretional evolution of a planetesimal swarm. I - A new simulation

NASA Technical Reports Server (NTRS)

Spaute, Dominique; Weidenschilling, Stuart J.; Davis, Donald R.; Marzari, Francesco

1991-01-01

This novel simulation of planetary accretion simultaneously treats many interacting heliocentric distance zones and characterizes planetesimals via Keplerian elements. The numerical code employed, in addition to following the size distribution and the orbit-element distribution of a planetesimal swarm from arbitrary size and orbit distributions, treats a small number of the largest bodies as discrete objects with individual orbits. The accretion algorithm used yields good agreement with the analytic solutions; agreement is also obtained with the results of Weatherill and Stewart (1989) for gravitational accretion of planetesimals having equivalent initial conditions.

Nattokinase-promoted tissue plasminogen activator release from human cells.

PubMed

Yatagai, Chieko; Maruyama, Masugi; Kawahara, Tomoko; Sumi, Hiroyuki

2008-01-01

When heated to a temperature of 70 degrees C or higher, the strong fibrinolytic activity of nattokinase in a solution was deactivated. Similar results were observed in the case of using Suc-Ala-Ala-Pro-Phe-pNA and H-D-Val-Leu-Lys-pNA, which are synthetic substrates of nattokinase. In the current study, tests were conducted on the indirect fibrinolytic effects of the substances containing nattokinase that had been deactivated through heating at 121 degrees C for 15 min. Bacillus subtilis natto culture solutions made from three types of bacteria strain were heat-treated and deactivated, and it was found that these culture solutions had the ability to generate tissue plasminogen activators (tPA) from vascular endothelial cells and HeLa cells at certain concentration levels. For example, it was found that the addition of heat-treated culture solution of the Naruse strain (undiluted solution) raises the tPA activity of HeLa cells to about 20 times that of the control. Under the same conditions, tPA activity was raised to a level about 5 times higher for human vascular endothelial cells (HUVEC), and to a level about 24 times higher for nattokinase sold on the market. No change in cell count was observed for HeLa cells and HUVEC in the culture solution at these concentrations, and the level of activity was found to vary with concentration. Copyright 2009 S. Karger AG, Basel.

Biosorption of hexavalent chromium from aqueous solutions by Macadamia nutshell powder

NASA Astrophysics Data System (ADS)

Pakade, Vusumzi Emmanuel; Ntuli, Themba Dominic; Ofomaja, Augustine Enakpodia

2017-10-01

Macadamia nutshell biosorbents treated in three different activating agents [raw Macadamia nutshell powder (RMN), acid-treated Macadamia nutshell (ATMN) and base-treated Macadamia nutshell (BTMN)] were investigated for the adsorption of hexavalent chromium [Cr(VI)] from aqueous solutions. Fourier transform infrared spectroscopy spectra of free and Cr(VI)-loaded sorbents as well as thermogravimetric analysis revealed that the acid and base treatments modified the surface properties of the sorbent. Surface characteristics were also evaluated by the scanning electron microscopy and surface area analyzer. The optimum conditions for the adsorption of Cr(VI) by sorbents were pH 2, contact time 10 h, adsorbent mass 0.2 g and concentration 100 mg L-1. The equilibrium data were fitted into the Langmuir, Freundlich, Redlich-Peterson and Sips isotherms, and no single model could clearly explain the sorption mechanism. Maximum binding capacities of 45.23, 44.83 and 42.44 mg g-1 for RMN, ATMN and BTMN, respectively, were obtained. The kinetic data were analyzed using the pseudo-first, pseudo-second and Elovich kinetic models, and it was observed that the pseudo-second-order model produced the best fit for the experimental data. Macadamia nutshell sorbents showed potential as low-cost adsorbent for the removal of Cr(VI) from aqueous solution.

High order solution of Poisson problems with piecewise constant coefficients and interface jumps

NASA Astrophysics Data System (ADS)

Marques, Alexandre Noll; Nave, Jean-Christophe; Rosales, Rodolfo Ruben

2017-04-01

We present a fast and accurate algorithm to solve Poisson problems in complex geometries, using regular Cartesian grids. We consider a variety of configurations, including Poisson problems with interfaces across which the solution is discontinuous (of the type arising in multi-fluid flows). The algorithm is based on a combination of the Correction Function Method (CFM) and Boundary Integral Methods (BIM). Interface and boundary conditions can be treated in a fast and accurate manner using boundary integral equations, and the associated BIM. Unfortunately, BIM can be costly when the solution is needed everywhere in a grid, e.g. fluid flow problems. We use the CFM to circumvent this issue. The solution from the BIM is used to rewrite the problem as a series of Poisson problems in rectangular domains-which requires the BIM solution at interfaces/boundaries only. These Poisson problems involve discontinuities at interfaces, of the type that the CFM can handle. Hence we use the CFM to solve them (to high order of accuracy) with finite differences and a Fast Fourier Transform based fast Poisson solver. We present 2-D examples of the algorithm applied to Poisson problems involving complex geometries, including cases in which the solution is discontinuous. We show that the algorithm produces solutions that converge with either 3rd or 4th order of accuracy, depending on the type of boundary condition and solution discontinuity.

A full potential flow analysis with realistic wake influence for helicopter rotor airload prediction

NASA Technical Reports Server (NTRS)

Egolf, T. Alan; Sparks, S. Patrick

1987-01-01

A 3-D, quasi-steady, full potential flow solver was adapted to include realistic wake influence for the aerodynamic analysis of helicopter rotors. The method is based on a finite difference solution of the full potential equation, using an inner and outer domain procedure for the blade flowfield to accommodate wake effects. The nonlinear flow is computed in the inner domain region using a finite difference solution method. The wake is modeled by a vortex lattice using prescribed geometry techniques to allow for the inclusion of realistic rotor wakes. The key feature of the analysis is that vortices contained within the finite difference mesh (inner domain) were treated with a vortex embedding technique while the influence of the remaining portion of the wake (in the outer domain) is impressed as a boundary condition on the outer surface of the finite difference mesh. The solution procedure couples the wake influence with the inner domain solution in a consistent and efficient solution process. The method has been applied to both hover and forward flight conditions. Correlation with subsonic and transonic hover airload data is shown which demonstrates the merits of the approach.

Assessments of quaternary ammonium compounds (QAC) for in-water treatment of mussel fouling in vessel internals and sea chests using an experimental seawater pipework system.

PubMed

Piola, Richard; Grandison, Clare

2017-01-01

The primary in-water emergency treatment method for mussel fouling of internal seawater systems of Royal Australian Navy vessels is to flush with a 1% detergent solution containing quaternary ammonium compounds (QAC). Parameters for application of this treatment are based on previous research; however, much of the research has been conducted at small-scales under controlled laboratory conditions. This study examined the efficacy of QAC solutions for treating mussel biofouling under realistic field conditions using experimental seawater piping systems. The efficacy of QAC solutions was highly dependent on the size of mussels present. Chemical treatments comprising 1, 2 and 5% v v -1 QAC solution were effective at killing large (50-92 mm) mussels in the pipework and sea chest of the system following 24 h exposure. In contrast, small mussels (10-30 mm) appeared resilient to the majority of treatment regimes. Differences in water temperature, DO and pH during dosing had no discernible impact on treatment efficacy.

Solution-Phase Processes of Macromolecular Crystallization

NASA Technical Reports Server (NTRS)

Pusey, Marc L.; Minamitani, Elizabeth Forsythe

2004-01-01

We have proposed, for the tetragonal form of chicken egg lysozyme, that solution phase assembly processes are needed to form the growth units for crystal nucleation and growth. The starting point for the self-association process is the monomeric protein, and the final crystallographic symmetry is defined by the initial dimerization interactions of the monomers and subsequent n-mers formed, which in turn are a function of the crystallization conditions. It has been suggested that multimeric proteins generally incorporate the underlying multimers symmetry into the final crystallographic symmetry. We posed the question of what happens to a protein that is known to grow as an n-mer when it is placed in solution conditions where it is monomeric. The trypsin-treated, or cut, form of the protein canavalin (CCAN) has been shown to nucleate and grow crystals as a trimer from neutral to slightly acidic solutions. Under these conditions the solution is composed almost wholly of trimers. The insoluble protein can be readily dissolved by weakly basic solution, which results in a solution that is monomeric. There are three possible outcomes to an attempt at crystallization of the protein under monomeric (high pH) conditions: 1) we will obtain the same crystals as under trimer conditions, but at different protein concentrations governed by the self association equilibria; 2) we will obtain crystals having a different symmetry, based upon a monomeric growth unit; 3) we will not obtain crystals. Obtaining the first result would be indicative that the solution-phase self-association process is critical to the crystal nucleation and growth process. The second result would be less clear, as it may also reflect a pH-dependent shift in the trimer-trimer molecular interactions. The third result, particularly for experiments in the transition pH's between trimeric and monomeric CCAN, would indicate that the monomer does not crystallize, and that solution phase self association is not part of the crystal nucleation and growth path. Results are presented for crystallization experiments of CCAN over the pH 6.8 to 9.6 range.

A novel LCD (coal tar) solution for psoriasis does not discolor naturally light or color-processed hair in an exaggerated exposure test model.

PubMed

Johnson, Colleen; Edison, Brenda; Brouda, Irina; Green, Barbara

2009-09-01

Scalp psoriasis is reported to occur in 50-80% of psoriasis sufferers. Treatment of scalp psoriasis requires special consideration of product esthetics and staining potential due to the presence of hair. To evaluate the potential of a new, marketed liquor carbonis distillate (LCD; coal tar) solution to discolor naturally light or color-processed hair under exaggerated exposure conditions. Samples of naturally light and color-processed hair from a single donor were exposed to LCD solution repeatedly over 14 days and via submergence for 24 h. Color of LCD-treated hair samples was compared with untreated control hair samples. LCD solution did not discolor naturally light or color-processed hair following repeated exposures and 24 h submergence. The marketed LCD solution does not appear to discolor naturally light or color-processed hair.

[Apheresis in children: procedures and outcome].

PubMed

Tummolo, Albina; Colella, Vincenzo; Bellantuono, Rosa; Giordano, Mario; Messina, Giovanni; Puteo, Flora; Sorino, Palma; De Palo, Tommaso

2012-01-01

Apheresis procedures are used in children to treat an increasing number of conditions by removing different types of substances from the bloodstream. In a previous study we evaluated the first results of our experience in children, emphasizing the solutions adopted to overcome technical difficulties and to adapt adult apheresis procedures to a pediatric population. The aim of the present study is to present data on a larger number of patients in whom apheresis was the main treatment. Ninety-three children (50 m, 43 f) affected by renal and/or extrarenal diseases were included. They were treated with LDL apheresis, protein A immunoadsorption, or plasma exchange. Our therapeutic protocol was the same as described in the previous study. Renal diseases and immunological disorders remained the most common conditions requiring this therapeutic approach. However, hemolytic uremic syndrome (HUS) was no longer the most frequent renal condition to be treated, as apheresis is currently the first treatment option only in cases of atypical HUS. In this series we also treated small children, showing that low weight should no longer be considered a contraindication to apheresis procedures. The low rate of complications and the overall satisfactory clinical results with increasingly advanced technical procedures make a wider use of apheresis in children realistic in the years to come.

Surface characteristics, corrosion and bioactivity of chemically treated biomedical grade NiTi alloy.

PubMed

Chembath, Manju; Balaraju, J N; Sujata, M

2015-11-01

The surface of NiTi alloy was chemically modified using acidified ferric chloride solution and the characteristics of the alloy surface were studied from the view point of application as a bioimplant. Chemically treated NiTi was also subjected to post treatments by annealing at 400°C and passivation in nitric acid. The surface of NiTi alloy after chemical treatment developed a nanogrid structure with a combination of one dimensional channel and two dimensional network-like patterns. From SEM studies, it was found that the undulations formed after chemical treatment remained unaffected after annealing, while after passivation process the undulated surface was filled with oxides of titanium. XPS analysis revealed that the surface of passivated sample was enriched with oxides of titanium, predominantly TiO2. The influence of post treatment on the corrosion resistance of chemically treated NiTi alloy was monitored using Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy (EIS) in Phosphate Buffered Saline (PBS) solution. In the chemically treated condition, NiTi alloy exhibited poor corrosion resistance due to the instability of the surface. On the other hand, the breakdown potential (0.8V) obtained was highest for the passivated samples compared to other surface treated samples. During anodic polarization, chemically treated samples displayed dissolution phenomenon which was predominantly activation controlled. But after annealing and passivation processes, the behavior of anodic polarization was typical of a diffusion controlled process which confirmed the enhanced passivity of the post treated surfaces. The total resistance, including the porous and barrier layer, was in the range of mega ohms for passivated surfaces, which could be attributed to the decrease in surface nickel content and formation of compact titanium oxide. The passivated sample displayed good bioactivity in terms of hydroxyapatite growth, noticed after 14days immersion in Hanks' solution. Copyright © 2015 Elsevier B.V. All rights reserved.

Stresses in adhesively bonded joints: A closed form solution. [plate theory

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.; Aydinoglu, M. N.

1980-01-01

The plane strain of adhesively bonded structures which consist of two different orthotropic adherents is considered. Assuming that the thicknesses of the adherends are constant and are small in relation to the lateral dimensions of the bonded region, the adherends are treated as plates. The transverse shear effects in the adherends and the in-plane normal strain in the adhesive are taken into account. The problem is reduced to a system of differential equations for the adhesive stresses which is solved in closed form. A single lap joint and a stiffened plate under various loading conditions are considered as examples. To verify the basic trend of the solutions obtained from the plate theory a sample problem is solved by using the finite element method and by treating the adherends and the adhesive as elastic continua. The plate theory not only predicts the correct trend for the adhesive stresses but also gives rather surprisingly accurate results.

Electrodegradation of the Acid Green 28 dye using Ti/β-PbO2 and Ti-Pt/β-PbO2 anodes.

PubMed

Irikura, Kallyni; Bocchi, Nerilso; Rocha-Filho, Romeu C; Biaggio, Sonia R; Iniesta, Jesús; Montiel, Vicente

2016-12-01

The statistical Response Surface Methodology (RSM) is applied to investigate the effect of different parameters (current density, j, NaCl concentration, [NaCl], pH, and temperature, θ) and their interactions on the electrochemical degradation of the Acid Green (AG) 28 dye using a Ti/β-PbO2 or Ti-Pt/β-PbO2 anode in a filter-press reactor. LC/MS is employed to identify intermediate compounds. For both anodes, the best experimental conditions are j = 50 mA cm(-2), [NaCl] = 1.5 g L(-1), pH = 5, and θ = 25 °C. After 3 h of electrolysis, a dye solution treated under these conditions presents the following parameters: electric charge per unit volume of the electrolyzed solution required for 90% decolorization (Q(90)) of 0.34-0.37 A h L(-1), %COD removal of ∼100%, specific energy consumption of 18-20 kW h m(-3), and %TOC removal of 32-33%. No loss of the β-PbO2 film is observed during all the experiments. The β-PbO2 films present excellent stability for solutions with pH ≥ 5 ([Pb(2+)] < 0.5 mg L(-1)). Chloroform is the only volatile organic halo compound present in the treated solution under those optimized conditions. Hydroxylated anthraquinone derivatives, aromatic chloramines, and naphthoquinones are formed during the electrolyses. The Ti/β-PbO2 and Ti-Pt/β-PbO2 anodes show significantly better performance than a commercial DSA anode for the electrochemical degradation of the AG 28 dye. The Ti/β-PbO2 anode, prepared as described in this work, is an excellent option for the treatment of textile effluents because of its low cost of fabrication and good performance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biodegradation of Azure-B dye by Serratia liquefaciens and its validation by phytotoxicity, genotoxicity and cytotoxicity studies.

PubMed

Haq, Izharul; Raj, Abhay; Markandeya

2018-04-01

The azo dyes in textile industry are a major source of environmental pollution and cause serious threat to aquatic flora and fauna. The present study aims to evaluate the potential of previously isolated lignin peroxidase (LiP) enzyme producing Serratia liquefaciens in degradation of Azure-B (AB) dye. S. liquefaciens showed rapid decolourisation of AB dye (100 mg L -1 ) in mineral salt medium (MSM) supplemented with 0.2% glucose and yeast extract, and more than 90% dye decolourisation was observed at 48 h when incubated at 30 °C. Decolourisation conditions were optimized by Response Surface Methodology (RSM) using Box-Behnken Designs (BBD). The dye degradation was further confirmed by ATR-FTIR and GC-MS analysis. Toxicological studies of untreated (UT) and bacterial treated (BT) AB dye solutions were studied by using phytotoxicity, genotoxicity and cytotoxicity endpoints. Phytotoxicity assay using Vigna radiata indicated that bacterial treatment led to detoxification of AB dye. Genotoxicity assay with Allium cepa showed that pure AB dye solutions significantly reduced mitotic index (MI) and induced various chromosomal abnormalities (CAs) like c-mitosis, stickiness, chromosome break, anaphase bridges, vagrant chromosomes and binucleated and micronucleated cell in the root tip cells, whereas, bacterial treated solutions induced relatively less genotoxicity in nature. Improved cell survivability (%) was also noted in kidney cell line (NRK-52E) after S. liquefaciens treated dye solutions than the pure dye solutions. The findings suggest that S. liquefaciens could be a potential bacterium for azo dye degradation, as it is effective in lowering of toxic effects of AB dye. Copyright © 2018 Elsevier Ltd. All rights reserved.

SEPARATION OF PLUTONIUM

DOEpatents

Maddock, A.G.; Smith, F.

1959-08-25

A method is described for separating plutonium from uranium and fission products by treating a nitrate solution of fission products, uranium, and hexavalent plutonium with a relatively water-insoluble fluoride to adsorb fission products on the fluoride, treating the residual solution with a reducing agent for plutonium to reduce its valence to four and less, treating the reduced plutonium solution with a relatively insoluble fluoride to adsorb the plutonium on the fluoride, removing the solution, and subsequently treating the fluoride with its adsorbed plutonium with a concentrated aqueous solution of at least one of a group consisting of aluminum nitrate, ferric nitrate, and manganous nitrate to remove the plutonium from the fluoride.

The effects of solution treatment on the mechanical properties of age-hardened A-286 bar stock at elevated and cryogenic temperature

NASA Technical Reports Server (NTRS)

Montano, J. W.

1972-01-01

The mechanical properties are presented of solution treated and age hardened A-286 corrosion resistant steel bar stock. Material solution treated at 899 C or 982 C, each followed by an age hardening treatment of 718 C, was evaluated. Test specimens manufactured from 1.50 inch (3.81 cm) diameter bar stock were tested at temperatures from +649 C to -253 C. The test data indicated excellent tensile, yield, elongation and reduction-in-area properties at all testing temperatures for both solution treated and aged materials. Cryogenic temperature notched tensile, impact, and shear tests indicated excellent notch strength, ductility, and shear values. There was very little difference in the mechanical properties of the two solution treated and aged materials. The only exception was that the 962 C solution treated and aged material had superior stress rupture properties at 649 C.

Guidance law development for aeroassisted transfer vehicles using matched asymptotic expansions

NASA Technical Reports Server (NTRS)

Calise, Anthony J.; Melamed, Nahum

1993-01-01

This report addresses and clarifies a number of issues related to the Matched Asymptotic Expansion (MAE) analysis of skip trajectories, or any class of problems that give rise to inner layers that are not associated directly with satisfying boundary conditions. The procedure for matching inner and outer solutions, and using the composite solution to satisfy boundary conditions is developed and rigorously followed to obtain a set of algebraic equations for the problem of inclination change with minimum energy loss. A detailed evaluation of the zeroth order guidance algorithm for aeroassisted orbit transfer is performed. It is shown that by exploiting the structure of the MAE solution procedure, the original problem, which requires the solution of a set of 20 implicit algebraic equations, can be reduced to a problem of 6 implicit equations in 6 unknowns. A solution that is near optimal, requires a minimum of computation, and thus can be implemented in real time and on-board the vehicle, has been obtained. Guidance law implementation entails treating the current state as a new initial state and repetitively solving the zeroth order MAE problem to obtain the feedback controls. Finally, a general procedure is developed for constructing a MAE solution up to first order, of the Hamilton-Jacobi-Bellman equation based on the method of characteristics. The development is valid for a class of perturbation problems whose solution exhibits two-time-scale behavior. A regular expansion for problems of this type is shown to be inappropriate since it is not valid over a narrow range of the independent variable. That is, it is not uniformly valid. Of particular interest here is the manner in which matching and boundary conditions are enforced when the expansion is carried out to first order. Two cases are distinguished-one where the left boundary condition coincides with, or lies to the right of, the singular region, and another one where the left boundary condition lies to the left of the singular region. A simple example is used to illustrate the procedure where the obtained solution is uniformly valid to O(Epsilon(exp 2)). The potential application of this procedure to aeroassisted plane change is also described and partially evaluated.

Kinetic Modeling of the Release of Ethylene Oxide from Sterilized Plastic Containers and its Interaction with Monoclonal Antibodies.

PubMed

Yu, Bryan Lei; Han, Jun; Hammond, Matthew; Wang, Xuemei; Zhang, Qingchun; Clausen, Andrew; Forster, Ronald; Eu, Mingda

Ethylene oxide (ETO) is commonly used to sterilize plastic containers, but the effects of residual amounts left after sterilization on protein therapeutics are still not well understood. Here we focus primarily on the factors that influence concentrations of ETO migrating from ETO-treated plastic containers into aqueous solution. A study was designed to investigate the kinetics of this process at various temperatures, and the kinetic data could be fit with a model based on a combination of Fickean diffusion and first-order chemical reaction (to account for observed hydrolysis of ETO). The diffusion and reaction rate constants thus obtained obey Arrhenius-like temperature dependence. These results indicate that for analytical methods involving extraction into water, measurements of residual ETO in a container must account for the effects of ETO hydrolysis. Further, the effects of salt concentration and pH of the fluid in the container on accumulated ETO levels were explored. Finally, interactions of ETO with anti-streptavidin (AntiSA) Immunoglobulin G1 (IgG1) and IgG2 antibodies were studied, with ETO adducts found on all methionine residues when incubated in solutions spiked with ETO at concentrations that could be reached (based on the kinetic studies) in ETO-treated plastic vials. Overall, the likelihood of observable ETO-protein modifications upon storage in ETO-sterilized containers will depend on a complex interplay of protein properties, formulation details, storage conditions, and amount of residual ETO initially in the container. Ethylene oxide (ETO) is commonly used to sterilize plastic containers, but the effects of residual amounts left after sterilization on protein therapeutics are still not well understood. Here we describe experiments exploring the factors that influence concentrations of ETO migrating from ETO-treated plastic containers into aqueous solution over time. Additionally, interactions of ETO with model antibodies were studied, with ETO adducts found on all methionine residues when incubated in solutions spiked with ETO at concentrations that could potentially be reached in ETO-treated plastic vials. Overall, the likelihood of observable ETO-protein modifications upon storage in ETO-sterilized containers will depend on a complex interplay of protein properties, formulation details, storage conditions, and amount of residual ETO initially in the container. © PDA, Inc. 2017.

Implementation study of patient-ready syringes containing 25 mg/mL methotrexate solution for use in treating ectopic pregnancy.

PubMed

Respaud, R; Gaudy, A S; Arlicot, C; Tournamille, J F; Viaud-Massuard, M C; Elfakir, C; Antier, D

2014-01-01

Ectopic pregnancy (EP) is a significant cause of morbidity and mortality during the first trimester of pregnancy. Small unruptured tubal pregnancies can be treated medically with a single dose of methotrexate (MTX). The aim of this study was to evaluate the stability of a 25 mg/mL solution of MTX to devise a secure delivery circuit for the preparation and use of this medication in the management of EP. MTX solutions were packaged in polypropylene syringes, stored over an 84-day period, and protected from light either at +2 to +8°C or at 23°C. We assessed the physical and chemical stability of the solutions at various time points over the storage period. A pharmaceutical delivery circuit was implemented that involved the batch preparation of MTX syringes. We show that 25 mg/mL MTX solutions remain stable over an 84-day period under the storage conditions tested. Standard doses were prepared, ranging from 50 mg to 100 mg. The results of this study suggest that MTX syringes can be prepared in advance by the pharmacy, ready to be dispensed at any time that a diagnosis of EP is made. The high stability of a 25 mg/mL MTX solution in polypropylene syringes makes it possible to implement a flexible and cost-effective delivery circuit for ready-to-use preparations of this drug, providing 24-hour access and preventing treatment delays.

Factors affecting the periapical healing process of endodontically treated teeth.

PubMed

Holland, Roberto; Gomes, João Eduardo; Cintra, Luciano Tavares Angelo; Queiroz, Índia Olinta de Azevedo; Estrela, Carlos

2017-01-01

Tissue repair is an essential process that reestablishes tissue integrity and regular function. Nevertheless, different therapeutic factors and clinical conditions may interfere in this process of periapical healing. This review aims to discuss the important therapeutic factors associated with the clinical protocol used during root canal treatment and to highlight the systemic conditions associated with the periapical healing process of endodontically treated teeth. The antibacterial strategies indicated in the conventional treatment of an inflamed and infected pulp and the modulation of the host's immune response may assist in tissue repair, if wound healing has been hindered by infection. Systemic conditions, such as diabetes mellitus and hypertension, can also inhibit wound healing. The success of root canal treatment is affected by the correct choice of clinical protocol. These factors are dependent on the sanitization process (instrumentation, irrigant solution, irrigating strategies, and intracanal dressing), the apical limit of the root canal preparation and obturation, and the quality of the sealer. The challenges affecting the healing process of endodontically treated teeth include control of the inflammation of pulp or infectious processes and simultaneous neutralization of unpredictable provocations to the periapical tissue. Along with these factors, one must understand the local and general clinical conditions (systemic health of the patient) that affect the outcome of root canal treatment prediction.

Factors affecting the periapical healing process of endodontically treated teeth

PubMed Central

Holland, Roberto; Gomes, João Eduardo; Cintra, Luciano Tavares Angelo; Queiroz, Índia Olinta de Azevedo; Estrela, Carlos

2017-01-01

Abstract Tissue repair is an essential process that reestablishes tissue integrity and regular function. Nevertheless, different therapeutic factors and clinical conditions may interfere in this process of periapical healing. This review aims to discuss the important therapeutic factors associated with the clinical protocol used during root canal treatment and to highlight the systemic conditions associated with the periapical healing process of endodontically treated teeth. The antibacterial strategies indicated in the conventional treatment of an inflamed and infected pulp and the modulation of the host's immune response may assist in tissue repair, if wound healing has been hindered by infection. Systemic conditions, such as diabetes mellitus and hypertension, can also inhibit wound healing. The success of root canal treatment is affected by the correct choice of clinical protocol. These factors are dependent on the sanitization process (instrumentation, irrigant solution, irrigating strategies, and intracanal dressing), the apical limit of the root canal preparation and obturation, and the quality of the sealer. The challenges affecting the healing process of endodontically treated teeth include control of the inflammation of pulp or infectious processes and simultaneous neutralization of unpredictable provocations to the periapical tissue. Along with these factors, one must understand the local and general clinical conditions (systemic health of the patient) that affect the outcome of root canal treatment prediction. PMID:29069143

Programmatic Summary: Self-Regulating, Self-Pressurizing Tubules for Integrated Circulatory Systems

DTIC Science & Technology

2009-02-01

Conditions: (i) 3- aminopropyl silane; (ii) 2-furoyl chloride, Et3N, CH2Cl2, 0 C to RT, 24 h; (iii) Compound 2, THF, RT, 24 h.; and (iv) Toluene, reflux... aminopropyl )trimethoxy silane. Next, we treated the amino-terminated slides with a solution of 2-furoyl chloride to yield furan functionalized slides...Conditions: (i) 3- aminopropyl silane; (ii) 2-furoyl chloride, Et3N, CH2Cl2, 0 C to RT, 24 h; (iii) Compound 2, THF, RT, 24 h.; and (iv) Toluene, reflux

Thirty Years of Orphan Drug Legislation and the Development of Drugs to Treat Rare Seizure Conditions: A Cross Sectional Analysis.

PubMed

Döring, Jan Henje; Lampert, Anette; Hoffmann, Georg F; Ries, Markus

2016-01-01

Epilepsy is a serious chronic health condition with a high morbidity impairing the life of patients and afflicted families. Many epileptic conditions, especially those affecting children, are rare disorders generating an urgent medical need for more efficacious therapy options. Therefore, we assessed the output of the US and European orphan drug legislations. Quantitative analysis of the FDA and EMA databases for orphan drug designations according to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) criteria. Within the US Orphan Drug Act 40 designations were granted delivering nine approvals, i.e. clobazam, diazepam viscous solution for rectal administration, felbamate, fosphenytoin, lamotrigine, repository corticotropin, rufinamide, topiramate, and vigabatrin. Since 2000 the EMA granted six orphan drug designations whereof two compounds were approved, i.e. rufinamide and stiripentol. In the US, two orphan drug designations were withdrawn. Orphan drugs were approved for conditions including Lennox-Gastaut syndrome, infantile spasms, Dravet syndrome, and status epilepticus. Comparing time to approval for rufinamide, which was approved in the US and the EU to treat rare seizure conditions, the process seems faster in the EU (2.2 years) than in the US (4.3 years). Orphan drug development in the US and in the EU delivered only few molecular entities to treat rare seizure disorders. The development programs focused on already approved antiepileptic drugs or alternative pharmaceutical formulations. Most orphan drugs approved in the US are not approved in the EU to treat rare seizures although some were introduced after 2000 when the EU adopted the Orphan Drug Regulation.

Fabrication of nanocomposite particles using a two-solution mixing-type spray nozzle for use in an inhaled curcumin formulation.

PubMed

Taki, Moeko; Tagami, Tatsuaki; Fukushige, Kaori; Ozeki, Tetsuya

2016-09-10

A unique two-solution mixing-type spray nozzle is useful for producing nanocomposite particles (microparticles containing drug nanoparticles) in one step. The nanocomposite particles can prevent nanoparticle aggregation. Curcumin has many reported pharmacological effects. Curcumin was entrapped in mannitol microparticles using a spray dryer coupled with a two-solution mixing-type spray nozzle to prepare "curcumin nanocomposite particles" and the application of these particles for inhalation formulations was investigated. Spray drying conditions (flow rate, concentration and inlet temperature) affected the size of both the resulting curcumin nanocomposite particles and the curcumin nanoparticles in the nanocomposite particles. The aerosol performance of the curcumin nanocomposite particles changed depending on the spray drying conditions and several conditions provided better deposition compared with the curcumin original powder. The curcumin nanocomposite particles showed an improved dissolution profile of curcumin compared with the original powder. Furthermore, the curcumin nanocomposite particles showed a higher cytotoxic effect compared with the curcumin original powder towards three cancer cell lines. Curcumin nanocomposite particles containing curcumin nanoparticles show promise as an inhalation formulation for treating lung-related diseases including cancer. Copyright © 2016. Published by Elsevier B.V.

Vitrification, encapsulation-vitrification and droplet-vitrification: a review.

PubMed

Sakai, Akira; Engelmann, Florent

2007-01-01

This paper discusses the importance of the successive steps of the vitrification technique and reviews the current development and use of vitrification and of the two derived protocols, encapsulation-vitrification and droplet-vitrification. Vitrification refers to the physical process by which a highly concentrated cryoprotective solution supercools to very low temperatures and finally solidifies into a metastable glass, without undergoing crystallization at a practical cooling rate. Samples are thus cryopreserved without detrimental intracellular ice formation. In a standard vitrification protocol, excised explants are precultured on medium enriched with sucrose, treated (loaded) with a loading solution composed of 2 M glycerol + 0.4 M sucrose, dehydrated with a highly concentrated vitrification solution [e.g. the PVS2 vitrification solution, which contains 30 percent (w/v) glycerol, 15 percent (w/v) ethylene glycol and 15 percent (w/v) DMSO and 0.4 M sucrose], frozen and rewarmed rapidly, unloaded with basal culture medium supplemented with 1.2 M sucrose, and then transferred to standard culture conditions. In the encapsulation-vitrification technique, the explants are encapsulated in alginate beads, loaded and dehydrated with a vitrification solution before rapid immersion in liquid nitrogen. In the droplet-freezing technique, excised explants are loaded, treated with the vitrification solution and frozen in individual microdroplets of vitrification solution placed on aluminium foils, which are immersed rapidly in liquid nitrogen. These three techniques have been applied to different tissues of over 100 plant species from temperate and tropical origins and the number of cases where they are being tested on a large scale or applied routinely is increasing.

The Equipment of Using AZOLLA for O2-Supplimentation and its Test

NASA Astrophysics Data System (ADS)

Liu, Xia-Shi; Chen, Min; Bian, Zu-Liang; Liu, Chung-Chu

The water-consuming amount in a long-term astro-navigation is large. In order to reduce the burden of water supply from Earth ground, the space station needs to resolve the problems of water supply. For this reason, the recovery and regeneration of urine solution of spacemen, and its utilization possess a key importance. Many investigations on this aspect have been reported. Our research based on "biological absorption-purification-UV photocatalytic oxidation" techniques with a relevant treating equipment that for a comprehensive treatment to fresh urine of spacemen has been created. In this equipment, the urine solution was used as the nutrient solution for the biological parts in ecological life ensurant system, after absorbing the nutrient, it was decomposed, metabolized and purified in some distance, and created a favorable condition for the follow-up oxidation treatment by UV-Photocatalytic Oxidation. After these two processes, the treated urine solution reached the GB5749-85 standard of water quality. Some main indexes are as table one. Chroma<5-15 Feculent degree-NTU-1.20-3 --5 Total rigidity-according to CaCO3-mg/L-3.60-450 N-NO3--mg/L-0.60-20 Soluble total solid-mg/L-543-1000 Bacterial gross-cfu/ml-13-100 Coliform group-No./L-<3-3 Key words-Photocatalytic Oxidation , Ultraviolet

Fabrication of hydroxyapatite and TiO 2 nanorods on microarc-oxidized titanium surface using hydrothermal treatment

NASA Astrophysics Data System (ADS)

Song, Ho-Jun; Kim, Ji-Woo; Kook, Min-Suk; Moon, Won-Jin; Park, Yeong-Joon

2010-09-01

AC-type microarc oxidation (MAO) and hydrothermal treatment techniques were used to enhance the bioactivity of commercially pure titanium (CP-Ti). The porous TiO 2 layer fabricated by the MAO treatment had a dominant anatase structure and contained Ca and P ions. The MAO-treated specimens were treated hydrothermally to form HAp crystallites on the titanium oxide layer in an alkaline aqueous solution (OH-solution) or phosphorous-containing alkaline solution (POH-solution). A small number of micro-sized hydroxyapatite (HAp) crystallites and a thin layer composed of nano-sized HAps were formed on the Ti-MAO-OH group treated hydrothermally in an OH-solution, whereas a large number of micro-sized HAp crystallites and dense anatase TiO 2 nanorods were formed on the Ti-MAO-POH group treated hydrothermally in a POH-solution. The layer of bone-like apatite that formed on the surface of the POH-treated sample after soaking in a modified simulated body fluid was thicker than that on the OH-treated samples.

Osmotic tolerance limits and membrane permeability characteristics of stallion spermatozoa treated with cholesterol.

PubMed

Glazar, Amanda I; Mullen, Steven F; Liu, Jun; Benson, James D; Critser, John K; Squires, Edward L; Graham, James K

2009-10-01

Stallion spermatozoa exhibit osmotic damage during the cryopreservation process. Recent studies have shown that the addition of cholesterol to spermatozoal membranes increases the cryosurvival of bull, ram and stallion spermatozoa, but the exact mechanism by which added cholesterol improves cryosurvival is not understood. The objectives of this study were to determine if adding cholesterol to stallion sperm membranes alters the osmotic tolerance limits and membrane permeability characteristics of the spermatozoa. In experiment one, stallion spermatozoa were treated with cholesterol-loaded cyclodextrin (CLC), subjected to anisotonic solutions and spermatozoal motility analyzed. The spermatozoa were then returned to isotonic conditions and the percentages of motile spermatozoa again determined. CLC treatment increased the osmotic tolerance limit of stallion spermatozoa in anisotonic solutions and when returned to isotonic conditions. The second and third experiments utilized an electronic particle counter to determine the plasma membrane characteristics of stallion spermatozoa. In experiment two, stallion spermatozoa were determined to behave as linear osmometers. In experiment three, spermatozoa were treated with CLC, incubated with different cryoprotectants (glycerol, ethylene glycol or dimethyl formamide) and their volume excursions measured during cryoprotectant removal at 5 degrees and 22 degrees C. Stallion spermatozoa were less permeable to the cryoprotectants at 5 degrees C than 22 degrees C. Glycerol was the least permeable cryoprotectant in control cells. The addition of CLC's to spermatozoa increased the permeability of stallion spermatozoa to the cryoprotectants. Therefore, adding cholesterol to spermatozoal membranes reduces the amount of osmotic stress endured by stallion spermatozoa during cryopreservation.

Intra- and extracellular dehydration-induced thirst-related behavior in an amphibian.

PubMed

Taylor, K; Mayer, L P; Propper, C R

The behavioral response to dehydration is critical to an animal's survival. Because of their permeable skin, amphibians are particularly sensitive to dehydrating conditions. We tested the hypothesis that different forms of dehydration induce water absorption response (WR) behavior in the desert spadefoot toad, Scaphiopus couchii. First, we determined the behavioral response to intracellular dehydration by treating fully hydrated toads with increasing concentrations of hypertonic solutions of NaCl or sucrose via intraperitoneal injection (i.p.). Animals that were treated to induce intracellular dehydration with either solute exhibited a significant increase in WR behavior compared to vehicle-treated controls. To distinguish that the response was a result of an increased osmotic gradient between the intra- and extracellular compartments, we treated fully hydrated animals i.p. with urea, which freely passes into the intracellular compartment and increases overall animal osmolarity. Urea treatment did not induce WR behavior. To determine the response to extracellular dehydration, the blood volume of fully hydrated toads was reduced via cardiac puncture, and the WR behavior was measured. Animals who had a reduction in blood volume exhibited a significant increase in WR behavior compared to sham-punctured controls. Our results are the first to demonstrate that multiple forms of dehydration can induce thirst-related behavior in amphibians.

Seawater-driven forward osmosis for enriching nitrogen and phosphorous in treated municipal wastewater: effect of membrane properties and feed solution chemistry.

PubMed

Xue, Wenchao; Tobino, Tomohiro; Nakajima, Fumiyuki; Yamamoto, Kazuo

2015-02-01

Seawater-driven forward osmosis (FO) is considered to be a novel strategy to concentrate nutrients in treated municipal wastewater for further recovery as well as simultaneous discharge of highly purified wastewater into the sea with low cost. As a preliminary test, the performance of FO membranes in concentrating nutrients was investigated by both batch experiments and model simulation approaches. With synthetic seawater as the draw solution, the dissolved organic carbon, phosphate, and ammonia in the effluent from a membrane bioreactor (MBR) treating municipal wastewater were 2.3-fold, 2.3-fold, and 2.1-fold, respectively, concentrated by the FO process with approximately 57% of water reduction. Most of the dissolved components, including trace metals in the MBR effluent, were highly retained (>80%) in the feed side, indicating high water quality of permeate to be discharged. The effect of membrane properties on the nutrient enrichment performance was investigated by comparing three types of FO membranes. Interestingly, a polyamide membrane possessing a high negative charge demonstrated a poor capability of retaining ammonia, which was hypothesized because of an ion exchange-like mechanism across the membrane prompted by the high ionic concentration of the draw solution. A feed solution pH of 7 was demonstrated to be an optimum condition for improving the overall retention of nutrients, especially for ammonia because of the pH-dependent speciation of ammonia/ammonium forms. The modeling results showed that higher than 10-fold concentrations of ammonia and phosphate are achievable by seawater-driven FO with a draw solution to feed solution volume ratio of 2:1. The enriched municipal wastewater contains nitrogen and phosphorous concentrations comparable with typical animal wastewater and anaerobic digestion effluent, which are used for direct nutrient recovery. Copyright © 2014 Elsevier Ltd. All rights reserved.

Iodine uptake by spinach (Spinacia oleracea L.) plants grown in solution culture: effects of iodine species and solution concentrations.

PubMed

Zhu, Y-G; Huang, Y-Z; Hu, Y; Liu, Y-X

2003-04-01

A hydroponic experiment was carried out to investigate the effects of iodine species and solution concentrations on iodine uptake by spinach (Spinacia oleracea L.). Five iodine concentrations (0, 1, 10, 50 and 100 microM) for iodate (IO(3)(-)) and iodide (I(-)) were used. Results show that higher concentrations of I(-) (> or =10 microM) had some detrimental effect on plant growth, while IO(3)(-) had little effect on the biomass production of spinach plants. Increases in iodine concentration in the growth solution significantly enhanced I concentrations in plant tissues. The detrimental effect of I(-) on plant growth was probably due to the excessively high accumulation of I in plant tissues. The solution-to-spinach leaf transfer factors (TF(leaf), fresh weight basis) for plants treated with iodide were between 14.2 and 20.7 at different solution concentrations of iodide; TF(leaf) for plants treated with iodate decreased gradually from 23.7 to 2.2 with increasing solution concentrations of iodate. The distribution coefficients (DCs) of I between leaves and roots were constantly higher for plants treated with iodate than those treated with iodide. DCs for plants treated with iodide increased with increasing solution concentrations of iodide, while DCs for plants treated with iodate (around 5.5) were similar across the range of solution concentrations of iodate used in this experiment. The implications of iodine accumulation in leafy vegetables in human iodine nutrition are also discussed. Copyright 2002 Elsevier Science Ltd.

Complex motivated behaviors for natural rewards following a binge-like regimen of morphine administration: mixed phenotypes of anhedonia and craving after short-term withdrawal

PubMed Central

Bai, Yunjing; Li, Yingying; Lv, Yaodi; Liu, Zhengkui; Zheng, Xigeng

2014-01-01

The anhedonia-like behaviors following about 1-week withdrawal from morphine were examined in the present study. Male rats were pretreated with either a binge-like morphine paradigm or daily saline injection for 5 days. Three types of natural reward were used, food reward (2.5, 4, 15, 30, 40, and 60% sucrose solutions), social reward (male rat) and sexual reward (estrous female rat). For each type of natural stimulus, consummatory behavior and motivational behaviors under varied testing conditions were investigated. The results showed that the morphine-treated rats significantly reduced their consumption of 2.5% sucrose solution during the 1-h consumption testing and their operant responding for 15, 30, and 40% sucrose solutions under a fixed ratio 1 (FR1) schedule. However, performance under a progressive ratio (PR) schedule increased in morphine-treated rats reinforced with 60% sucrose solution, but not in those reinforced with sucrose concentrations lower than 60%. Pretreatment with morphine significantly decreased the male rats' ejaculation frequency (EF) during the 1-h copulation testing, and impaired the maintenance of appetitive motivations to sexual and social stimuli under a free-approach condition. Moreover, the morphine-treated rats demonstrated a diminished motivation to approach social stimulus in the effort-based appetitive behavior test but showed a remarkable increase in motivation to approach sexual stimulus in the risky appetitive behavior test. These results demonstrated some complex motivated behaviors following about 1 week of morphine withdrawal: (1) The anhedonia-like behavior was consistently found in animals withdrawn from morphine. However, for a given reward, there was often a dissociation of the consummatory behaviors from the motivational behaviors, and whether the consummatory or the motivational anhedonia-like behaviors could be discovered heavily depended on the type and magnitude of the reward and the type of testing task; (2) These anhedonia-like behaviors coexisted with a craving for the high-incentive reward which was evidenced by the increased PR performance for the 60% sucrose solution and the heightened risky appetitive behavior for the sexual stimulus. The craving for the high-incentive reward alongside with the impaired inhibitory control in drug-withdrawn subjects might form one of psychological mechanisms underlying drug relapse after withdrawal. PMID:24550799

Transient well flow in layered aquifer systems: the uniform well-face drawdown solution

NASA Astrophysics Data System (ADS)

Hemker, C. J.

1999-11-01

Previously a hybrid analytical-numerical solution for the general problem of computing transient well flow in vertically heterogeneous aquifers was proposed by the author. The radial component of flow was treated analytically, while the finite-difference technique was used for the vertical flow component only. In the present work the hybrid solution has been modified by replacing the previously assumed uniform well-face gradient (UWG) boundary condition in such a way that the drawdown remains uniform along the well screen. The resulting uniform well-face drawdown (UWD) solution also includes the effects of a finite diameter well, wellbore storage and a thin skin, while partial penetration and vertical heterogeneity are accommodated by the one-dimensional discretization. Solutions are proposed for well flow caused by constant, variable and slug discharges. The model was verified by comparing wellbore drawdowns and well-face flux distributions with published numerical solutions. Differences between UWG and UWD well flow will occur in all situations with vertical flow components near the well, which is demonstrated by considering: (1) partially penetrating wells in confined aquifers, (2) fully penetrating wells in unconfined aquifers with delayed response and (3) layered aquifers and leaky multiaquifer systems. The presented solution can be a powerful tool for solving many well-hydraulic problems, including well tests, flowmeter tests, slug tests and pumping tests. A computer program for the analysis of pumping tests, based on the hybrid analytical-numerical technique and UWG or UWD conditions, is available from the author.

Some examples of exact and approximate solutions in small particle scattering - A progress report

NASA Technical Reports Server (NTRS)

Greenberg, J. M.

1974-01-01

The formulation of basic equations from which the scattering of radiation by a localized variation in a medium is discussed. These equations are developed in both the differential and the integral form. Primary interest is in the scattering of electromagnetic waves for which the solution of the vector wave equation with appropriate boundary conditions must be considered. Scalar scattering by an infinite homogeneous isotropic circular cylinder, and scattering of electromagnetic waves by infinite circular cylinders are treated, and the case of the finite circular cylinder is considered. A procedure is given for obtaining angular scattering distributions from spheroids.

The pulsating orb: solving the wave equation outside a ball

PubMed Central

2016-01-01

Transient acoustic waves are generated by the oscillations of an object or are scattered by the object. This leads to initial-boundary value problems (IBVPs) for the wave equation. Basic properties of this equation are reviewed, with emphasis on characteristics, wavefronts and compatibility conditions. IBVPs are formulated and their properties reviewed, with emphasis on weak solutions and the constraints imposed by the underlying continuum mechanics. The use of the Laplace transform to treat the IBVPs is also reviewed, with emphasis on situations where the solution is discontinuous across wavefronts. All these notions are made explicit by solving simple IBVPs for a sphere in some detail. PMID:27279773

A simple homogeneous model for regular and irregular metallic wire media samples

NASA Astrophysics Data System (ADS)

Kosulnikov, S. Y.; Mirmoosa, M. S.; Simovski, C. R.

2018-02-01

To simplify the solution of electromagnetic problems with wire media samples, it is reasonable to treat them as the samples of a homogeneous material without spatial dispersion. The account of spatial dispersion implies additional boundary conditions and makes the solution of boundary problems difficult especially if the sample is not an infinitely extended layer. Moreover, for a novel type of wire media - arrays of randomly tilted wires - a spatially dispersive model has not been developed. Here, we introduce a simplistic heuristic model of wire media samples shaped as bricks. Our model covers WM of both regularly and irregularly stretched wires.

Optimization of process factors for self-healing vanadium-based conversion coating on AZ31 magnesium alloy

NASA Astrophysics Data System (ADS)

Li, Kun; Liu, Junyao; Lei, Ting; Xiao, Tao

2015-10-01

A self-healing vanadium-based conversion coating was prepared on AZ31 magnesium alloy. The optimum operating conditions including vanadia solution concentration, pH and treating temperature for obtaining the best corrosion protective vanadia coatings and improved localized corrosion resistance to the magnesium substrate were determined by an orthogonal experiment design. Surface morphology and composition of the resultant conversion coatings were investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The self-healing behavior of the coating was investigated by cross-cut immersion test and electrochemical impedance spectroscopy (EIS) measurements in 3.5% NaCl solution.

Measurement of diffusion in fluid systems: Applications to the supercritical fluid region

NASA Astrophysics Data System (ADS)

Bruno, Thomas J.

1994-04-01

The experimental procedures that are applicable to the measurement of diffusion in supercritical fluid solutions are reviewed. This topic is of great importance to the proper design of advanced aircraft and turbine fuels, since the fuels on these aircraft may sometimes operate under supercritical fluid conditions. More specifically, we will consider measurements of the binary interaction diffusion coefficient D exp 12 of a solute (species 1) and the solvent (species 2). In this discussion, the supercritical fluid is species 2, and the solute, species 1, will be at a relatively low concentration, sometimes approaching infinite dilution. After a brief introduction to the concept of diffusion, we will discuss in detail the use of chromatographic methods, and then briefly treat light scattering, nuclear magnetic resonance spectra, and physical methods.

Inocoterone and acne. The effect of a topical antiandrogen: results of a multicenter clinical trial.

PubMed

Lookingbill, D P; Abrams, B B; Ellis, C N; Jegasothy, B V; Lucky, A W; Ortiz-Ferrer, L C; Savin, R C; Shupack, J L; Stiller, M J; Zone, J J

1992-09-01

Because acne is androgen dependent, antiandrogen therapy might improve the condition. Inocoterone acetate (RU 882) is a nonsteroidal antiandrogen that binds to the androgen receptor and has antiandrogenic activity in animal models. To test its topical effect on acne, 126 male subjects with facial acne completed a 16-week, multi-center, double-blind study in which the twice-daily application of a 10% solution of inocoterone was compared with vehicle solution. Baseline and monthly examinations included acne lesion counts and general and endocrine laboratory tests. Inflammatory papules and pustules showed greater reduction in the inocoterone-treated subjects than in the subjects treated with vehicle. This difference achieved statistical significance by week 12 (24% reduction vs 10%) and week 16 (26% reduction vs 13%) and, with longitudinal analysis, throughout the course of the study. Global assessments and changes in comedo counts and sebum excretion rates were not significantly different between the groups. No serious adverse reactions were encountered. In this double-blind study of 126 male subjects with acne, a topical solution of the antiandrogen inocoterone, compared with vehicle, produced a modest but statistically significant reduction in the number of inflammatory acne lesions.

Compatibility Testing of Polymeric Materials for the Urine Processor Assembly (UPA) of International Space Station (ISS)

NASA Technical Reports Server (NTRS)

Wingard, Charles D.

2003-01-01

In the International Space Station (ISS), astronauts will convert urine into potable water with the Urine Processor Assembly (UPA) by a distillation process. The urine is pre-treated, containing flush water and stabilizers. About 2.5% solids in the urine are concentrated up to 16% brine through distillation. Dynamic mechanical analysis (DMA) in the stress relaxation mode was primarily used to test 15 polymeric UPA materials for compatibility with the pre-treated and brine solutions. There were concerns that chromium trioxide (CrO3), a stabilizer not in the original pre-treat formulation for similar compatibility testing in 2000, could have an adverse effect on these polymers. DMA testing is partially complete for polymeric material samples immersed in the two solutions at room temperature for as long as 200 days. By comparing each material (conditioned and virgin), the stress relaxation modulus (E) was determined for short-term use and predicted for as long as a 10-year use in space. Such a delta E showed a decrease of as much as 79% for a Nylon material, but an increase as much as 454% for a polysulfone material, with increasing immersion time.

Chemical Changes in Nonthermal Plasma-Treated N-Acetylcysteine (NAC) Solution and Their Contribution to Bacterial Inactivation.

PubMed

Ercan, Utku K; Smith, Josh; Ji, Hai-Feng; Brooks, Ari D; Joshi, Suresh G

2016-02-02

In continuation of our previous reports on the broad-spectrum antimicrobial activity of atmospheric non-thermal dielectric barrier discharge (DBD) plasma treated N-Acetylcysteine (NAC) solution against planktonic and biofilm forms of different multidrug resistant microorganisms, we present here the chemical changes that mediate inactivation of Escherichia coli. In this study, the mechanism and products of the chemical reactions in plasma-treated NAC solution are shown. UV-visible spectrometry, FT-IR, NMR, and colorimetric assays were utilized for chemical characterization of plasma treated NAC solution. The characterization results were correlated with the antimicrobial assays using determined chemical species in solution in order to confirm the major species that are responsible for antimicrobial inactivation. Our results have revealed that plasma treatment of NAC solution creates predominantly reactive nitrogen species versus reactive oxygen species, and the generated peroxynitrite is responsible for significant bacterial inactivation.

Chemical Changes in Nonthermal Plasma-Treated N-Acetylcysteine (NAC) Solution and Their Contribution to Bacterial Inactivation

PubMed Central

Ercan, Utku K.; Smith, Josh; Ji, Hai-Feng; Brooks, Ari D.; Joshi, Suresh G.

2016-01-01

In continuation of our previous reports on the broad-spectrum antimicrobial activity of atmospheric non-thermal dielectric barrier discharge (DBD) plasma treated N-Acetylcysteine (NAC) solution against planktonic and biofilm forms of different multidrug resistant microorganisms, we present here the chemical changes that mediate inactivation of Escherichia coli. In this study, the mechanism and products of the chemical reactions in plasma-treated NAC solution are shown. UV-visible spectrometry, FT-IR, NMR, and colorimetric assays were utilized for chemical characterization of plasma treated NAC solution. The characterization results were correlated with the antimicrobial assays using determined chemical species in solution in order to confirm the major species that are responsible for antimicrobial inactivation. Our results have revealed that plasma treatment of NAC solution creates predominantly reactive nitrogen species versus reactive oxygen species, and the generated peroxynitrite is responsible for significant bacterial inactivation. PMID:26832829

Implementation Study of Patient-Ready Syringes Containing 25 mg/mL Methotrexate Solution for Use in Treating Ectopic Pregnancy

PubMed Central

Respaud, R.; Gaudy, A. S.; Arlicot, C.; Tournamille, J. F.; Viaud-Massuard, M. C.; Elfakir, C.; Antier, D.

2014-01-01

Background. Ectopic pregnancy (EP) is a significant cause of morbidity and mortality during the first trimester of pregnancy. Small unruptured tubal pregnancies can be treated medically with a single dose of methotrexate (MTX). Objective. The aim of this study was to evaluate the stability of a 25 mg/mL solution of MTX to devise a secure delivery circuit for the preparation and use of this medication in the management of EP. Method. MTX solutions were packaged in polypropylene syringes, stored over an 84-day period, and protected from light either at +2 to +8°C or at 23°C. We assessed the physical and chemical stability of the solutions at various time points over the storage period. A pharmaceutical delivery circuit was implemented that involved the batch preparation of MTX syringes. Results. We show that 25 mg/mL MTX solutions remain stable over an 84-day period under the storage conditions tested. Standard doses were prepared, ranging from 50 mg to 100 mg. The results of this study suggest that MTX syringes can be prepared in advance by the pharmacy, ready to be dispensed at any time that a diagnosis of EP is made. Conclusion. The high stability of a 25 mg/mL MTX solution in polypropylene syringes makes it possible to implement a flexible and cost-effective delivery circuit for ready-to-use preparations of this drug, providing 24-hour access and preventing treatment delays. PMID:24900977

Ductilization of High-Strength Magnesium Alloys

DTIC Science & Technology

2012-09-17

ductility in this system. Figure 4 compares true stress strain curves measured for the solution-treated and peak-aged conditions. Fractography of the...plane 1.274 1.094 1.213 Figure 4. Measured true stress-strain curves and fractography of WE43 Mg alloy Figure 3. FLAPW...Therefore, the enhancement of grain boundary cohesion plays an important role in the improvement of ductility. Figure 5 Fractography of WE43 at

Escherichia coli cellular responses to exposure to atmospheric-pressure dielectric barrier discharge plasma-treated N-acetylcysteine solution.

PubMed

Ercan, U K; Sen, B; Brooks, A D; Joshi, S G

2018-04-06

To understand the underlying cellular mechanisms during inactivation of Escherichia coli in response to antimicrobial solution of nonthermal plasma-activated N-acetylcysteine (NAC). The recommended techniques were used to demonstrate E. coli cellular and transcriptomic changes caused associated with peroxynitrite and compared with plasma-treated NAC solution. The findings demonstrate that E. coli cells respond to plasma-treated NAC and undergo severe oxidative and nitrosative stress, and leading to stress-induced damages to different components of bacterial cells, which includes loss of membrane potential, formation of oxidized glutathione (GSSG), formation of nitrotyrosine (a known marker of nitrosative stress), DNA damage, and generated a prominent pool of peroxynitrite. Reverse-transcriptase (RT)-polymerase chain reaction analysis of reactive nitrogen species (RNS) responsive genes indicated their differential expressions. For the first time, we report that the plasma-treated NAC solution activates predominantly nitrosative stress-responsive genes in E. coli and is responsible for cell death. The reactive species generated in solutions by nonthermal plasma treatment depends on the type of solution or solvent used. The plasma-treated NAC solution rapidly inactivates E. coli, mostly involving highly RNS generated in NAC solution, and has high potential as disinfectant. © 2018 The Society for Applied Microbiology.

The attachment of V79 and human periodontal ligament fibroblasts on periodontally involved root surfaces following treatment with EDTA, citric acid, or tetracycline HCL: an SEM in vitro study.

PubMed

Chandra, R Viswa; Jagetia, Ganesh Chandra; Bhat, K Mahalinga

2006-02-15

The present in vitro study has been designed to establish and compare the effects of citric acid, EDTA, and tetracycline HCl on human periodontally diseased roots on the structure, attachment, and orientation of V79 (primary Chinese hamster lung fibroblasts) cells and human periodontal ligament fibroblasts (HPDL). Commercially available V79 cells and HPDL derived from healthy human third molars were used in this study. These fibroblasts were left in solution for seven days in order to attain confluence. Forty single-rooted teeth were obtained from patients diagnosed with periodontitis. The crown part was removed under constant irrigation and the root was split vertically into two equal halves, thus, yielding 80 specimens. Following scaling and root planing, the specimens were washed with phosphate buffered saline (PBS) and kept in 50 microg/ml gentamycin sulphate solution for 24 hours. The root pieces were then treated as follows: citric acid at pH 1, 24% EDTA, or with a 10% solution of tetracycline HCl and were then placed in V79 fibroblast cultures and HPDL cultures. The specimens were harvested after four weeks and were fixed in 2.5% glutaraldehyde in PBS before preparation for scanning electron microscopy (SEM). The behavior of V79 cells was similar to that of human periodontal ligament cells on root conditioned surfaces. V79 and HPDL showed a healthy morphology on root surfaces treated with citric acid and EDTA and a relatively unhealthy appearance on root surfaces treated with tetracycline HCl and distilled water (control group). The results suggest the use of citric acid and EDTA as root conditioning agents favorably affects the migration, attachment, and morphology of fibroblasts on human root surfaces, which may play a significant role in periodontal healing and regeneration.

Degradation of caffeic acid in subcritical water and online HPLC-DPPH assay of degradation products.

PubMed

Khuwijitjaru, Pramote; Suaylam, Boonyanuch; Adachi, Shuji

2014-02-26

Caffeic acid was subjected to degradation under subcritical water conditions within 160-240 °C and at a constant pressure of 5 MPa in a continuous tubular reactor. Caffeic acid degraded quickly at these temperatures; the main products identified by liquid chromatography-diode array detection/mass spectrometry were hydroxytyrosol, protocatechuic aldehyde, and 4-vinylcatechol. The reaction rates for the degradation of caffeic acid and the formation of products were evaluated. Online high-performance liquid chromatography/2,2-diphenyl-1-picryhydrazyl assay was used to determine the antioxidant activity of each product in the solution. It was found that the overall antioxidant activity of the treated solution did not change during the degradation process. This study showed a potential of formation of antioxidants from natural phenolic compounds under these subcritical water conditions, and this may lead to a discovering of novel antioxidants compounds during the extraction by this technique.

Boundary value problem for the solution of magnetic cutoff rigidities and some special applications

NASA Technical Reports Server (NTRS)

Edmonds, Larry

1987-01-01

Since a planet's magnetic field can sometimes provide a spacecraft with some protection against cosmic ray and solar flare particles, it is important to be able to quantify this protection. This is done by calculating cutoff rigidities. An alternate to the conventional method (particle trajectory tracing) is introduced, which is to treat the problem as a boundary value problem. In this approach trajectory tracing is only needed to supply boundary conditions. In some special cases, trajectory tracing is not needed at all because the problem can be solved analytically. A differential equation governing cutoff rigidities is derived for static magnetic fields. The presense of solid objects, which can block a trajectory and other force fields are not included. A few qualititative comments, on existence and uniqueness of solutions, are made which may be useful when deciding how the boundary conditions should be set up. Also included are topics on axially symmetric fields.

Selective Cleavage of the Aryl Ether Bonds in Lignin for Depolymerization by Acidic Lithium Bromide Molten Salt Hydrate under Mild Conditions.

PubMed

Yang, Xiaohui; Li, Ning; Lin, Xuliang; Pan, Xuejun; Zhou, Yonghong

2016-11-09

The present study demonstrates that the concentrated lithium bromide (LiBr) solution with acid as catalyst was able to selectively cleave the β-O-4 aryl ether bond and lead to lignin depolymerization under mild conditions (e.g., in 60% LiBr with 0.3 M HCl at 110 °C for 2 h). Four industrial lignins from different pulping and biorefining processes, including softwood kraft lignin (SKL), hardwood kraft lignin (HKL), softwood ethanol organosolv lignin (EOL), and acid corncob lignin (ACL), were treated in the LiBr solution. The molecular weight, functional group, and interunit linkages of the lignins were characterized using GPC, FTIR, and NMR. The results indicated that the β-O-4 aryl ether bonds of the lignins were selectively cleaved, and both LiBr and HCl played crucial roles in catalyzing the cleavage of the ether bonds.

Blocked Force and Loading Calculations for LaRC THUNDER Actuators

NASA Technical Reports Server (NTRS)

Campbell, Joel F.

2007-01-01

An analytic approach is developed to predict the performance of LaRC Thunder actuators under load and under blocked conditions. The problem is treated with the Von Karman non-linear analysis combined with a simple Raleigh-Ritz calculation. From this, shape and displacement under load combined with voltage are calculated. A method is found to calculate the blocked force vs voltage and spring force vs distance. It is found that under certain conditions, the blocked force and displacement is almost linear with voltage. It is also found that the spring force is multivalued and has at least one bifurcation point. This bifurcation point is where the device collapses under load and locks to a different bending solution. This occurs at a particular critical load. It is shown this other bending solution has a reduced amplitude and is proportional to the original amplitude times the square of the aspect ratio.

Formulation and stability of an extemporaneous 0.02% chlorhexidine digluconate ophthalmic solution.

PubMed

Lin, Shu-Chiao; Huang, Chih-Fen; Shen, Li-Jiuan; Wang, Hsueh-Ju; Lin, Chia-Yu; Wu, Fe-Lin Lin

2015-12-01

Acanthamoeba keratitis is difficult to treat because Acanthamoeba cysts are resistant to the majority of antimicrobial agents. Despite the efficacy of 0.02% chlorhexidine in treating Acanthamoeba keratitis, a lack of data in the literature regarding the formulation's stability limits its clinical use. The objective of this study was to develop an optimal extemporaneous 0.02% chlorhexidine digluconate ophthalmic formulation for patients in need. With available active pharmaceutical ingredients, 0.02% chlorhexidine digluconate sample solutions were prepared by diluting with BSS Plus Solution or acetate buffer. Influences of the buffer, type of container, and temperature under daily-open condition were assessed based on the changes of pH values and chlorhexidine concentrations of the test samples weekly. To determine the beyond-use date, the optimal samples were stored at 2-8°C or room temperature, and analyzed at time 0 and at Week 1, Week 2, Week 3, Week 4, Week 5, Week 8, Week 12, and Week 24. Despite chlorhexidine exhibiting better stability in acetate buffer than in BSS solution, its shelf-life was < 14 days when stored in a light-resistant low-density polyethylene container. The acetate-buffered 0.02% chlorhexidine digluconate solution stored in light-resistant high-density polyethylene eyedroppers did not exhibit significant changes in pH or strength at any time interval. The acetate-buffered 0.02% chlorhexidine digluconate ophthalmic solution stored in light-resistant high-density polyethylene eyedroppers demonstrated excellent stability at 2-25°C for 6 months after being sealed and for 1 month after opening. This finding will enable us to prepare 0.02% chlorhexidine digluconate ophthalmic solutions based on a doctor's prescription. Copyright © 2014. Published by Elsevier B.V.

Experiencing Experimentation and Project Design.

ERIC Educational Resources Information Center

Demchik, Michael J.

2001-01-01

Introduces the pea plant experiment targeted to determine the effects of Knop's solution, a solution containing all the necessary minerals, on plant growth. Compares two groups of pea plants, one treated with Knop's solution and one treated with demineralized water. (YDS)

Two-strain Tuberculosis Transmission Model under Three Control Strategies

NASA Astrophysics Data System (ADS)

Rayhan, S. N.; Bakhtiar, T.; Jaharuddin

2017-03-01

In 1997, Castillo-Chavez and Feng developed a two-strain tuberculosis (TB) model, which is typical TB and resistant TB. Castillo-Chavez and Feng’s model was then subsequently developed by Jung et al. (2002) by adding two control variables. In this work, Jung et al.’s model was modified by introducing a new control variable so that there are three controls, namely chemoprophylaxis and two treatment strategies, with the application of three different scenarios related to the objective functional form and control application. Pontryagin maximum principle was applied to derive the differential equations system as a condition that must be satisfied by the optimal control variables. Furthermore, the fourth-order Runge-Kutta method was exploited to determine the numerical solution of the optimal control problem. In this numerical solution, it is shown that the controls treated on TB transmission model provide a good effect because latent and infected individuals are decreasing, and the number of individuals that is treated effectively is increasing.

Pretreatment of wheat straw by nonionic surfactant-assisted dilute acid for enhancing enzymatic hydrolysis and ethanol production.

PubMed

Qi, Benkun; Chen, Xiangrong; Wan, Yinhua

2010-07-01

Pretreating wheat straw (WS) with combined use of varied sulfuric acid concentration (0-3%, w/v) and Tween 20 concentration (0-1%) was investigated in an attempt to enhance the hydrolysis and fermentability of pretreated WS. Enzymatic hydrolysis yield of glucan and xylan and ethanol production by simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) were significantly affected by the amount of Tween 20 added during acid pretreatment. Any further addition of Tween 20 in either hydrolysis stage or fermentation stage only led to small increase in glucan conversion and ethanol production. Determination of adsorption of cellulases during hydrolysis showed that Tween 20-assisted acid treated straw solution contained more free cellulases than individual acid treated straw solution, indicating that modification of lignin surface by Tween 20 added during pretreatment likely occurred. In addition, the effects of pretreatment conditions on overall recovery of glucose and xylose after pretreatment and enzymatic hydrolysis were also investigated. Copyright 2010 Elsevier Ltd. All rights reserved.

Rebamipide increases the amount of mucin-like substances on the conjunctiva and cornea in the N-acetylcysteine-treated in vivo model.

PubMed

Urashima, Hiroki; Okamoto, Takashi; Takeji, Yasuhiro; Shinohara, Hisashi; Fujisawa, Shigeki

2004-08-01

Rebamipide increases the amount of mucin-like substances in the stomach. We aimed to determine the effects of rebamipide on the amount of mucin-like substances in the conjunctiva and cornea of N-acetylcysteine-treated eyes. Furthermore, we attempted to evaluate the effects of rebamipide on the wound healing of N-acetylcysteine-treated eyes. The model was created by instilling 10% N-acetylcysteine solutions into rabbit eyes. Rebamipide was then applied on the day following the completion of N-acetylcysteine treatment. The amount of mucin-like substances on the conjunctiva and cornea was measured using the Alcian-blue binding method. The degree of damage was evaluated using scores based on the areas and densities of the cornea and conjunctival after staining using a rose Bengal solution under blind conditions. Rebamipide increased the level of mucin-like substances on the conjunctiva of N-acetylcysteine-treated eyes when instilled at concentrations of 0.3% or higher, and 1% rebamipide increased the amount of mucin-like substances covering the cornea. Moreover, 1% rebamipide improved the rose Bengal scores of the cornea and conjunctiva in N-acetylcysteine-treated eyes. Rebamipide increased mucin-like substances on the cornea and conjunctiva of N-acetylcysteine-treated eyes. In accordance with the mucin-increasing effects, rebamipide improved the rose Bengal scores for the cornea and conjunctiva of N-acetylcysteine-treated eyes. However, the relevance of these findings to dry eyes is unclear because it is not known whether the change in mucus expression in the N-acetylcysteine model is similar to what occurs in aqueous tear deficiency. Consequently, it may be worth trying on an animal model of keratoconjunctivitis sicca.

Study on improving viscosity of polymer solution based on complex reaction

NASA Astrophysics Data System (ADS)

Sun, G.; Li, D.; Zhang, D.; Xu, T. H.

2018-05-01

The current status of polymer flooding Technology on high salinity oil reservoir is not ideal. A method for increasing the viscosity of polymer solutions is urgently needed. This paper systematically studied the effect of ions with different mass concentrations on the viscosity of polymer solutions. Based on the theory of complex reaction, a countermeasure of increasing viscosity of polymer solution under conditions of high salinity reservoir was proposed. The results show that Ca2+ and Mg2+ have greater influence on the solution viscosity than K+ and Na+. When the concentration of divalent ions increases from 0 mg/L to 80 mg/L, the viscosity of the polymer solution decreases from 210 mPa·s to 38.6 mPa·s. The viscosity of the polymer solution prepared from the sewage treated with the Na2C2O4 increased by 25.3%. Atomic force microscopy test results show that Na2C2O4 can effectively shield the divalent metal ions, so that the polymer molecules in the solution stretch more, thereby increasing the solution viscosity. Atomic force microscopy test results show that Na2C2O4 can effectively shield the divalent metal ions, so that the polymer molecules in the solution stretch more, thereby increasing the solution viscosity.

Structural Characterization of the Degradation Products of a Minor Natural Sweet Diterpene Glycoside Rebaudioside M under Acidic Conditions

PubMed Central

Prakash, Indra; Chaturvedula, Venkata Sai Prakash; Markosyan, Avetik

2014-01-01

Degradation of rebaudioside M, a minor sweet component of Stevia rebaudiana Bertoni, under conditions that simulated extreme pH and temperature conditions has been studied. Thus, rebaudioside M was treated with 0.1 M phosphoric acid solution (pH 2.0) and 80 °C temperature for 24 h. Experimental results indicated that rebaudioside M under low pH and higher temperature yielded three minor degradation compounds, whose structural characterization was performed on the basis of 1D (1H-, 13C-) & 2D (COSY, HSQC, HMBC) NMR, HRMS, MS/MS spectral data as well as enzymatic and acid hydrolysis studies. PMID:24424316

SULFIDE METHOD PLUTONIUM SEPARATION

DOEpatents

Duffield, R.B.

1958-08-12

A process is described for the recovery of plutonium from neutron irradiated uranium solutions. Such a solution is first treated with a soluble sullide, causing precipitation of the plutoniunn and uraniunn values present, along with those impurities which form insoluble sulfides. The precipitate is then treated with a solution of carbonate ions, which will dissolve the uranium and plutonium present while the fission product sulfides remain unaffected. After separation from the residue, this solution may then be treated by any of the usual methods, such as formation of a lanthanum fluoride precipitate, to effect separation of plutoniunn from uranium.

Ammonia, phosphate, phenol, and copper(II) removal from aqueous solution by subsurface and surface flow constructed wetland.

PubMed

Mojiri, Amin; Ahmad, Zakiah; Tajuddin, Ramlah Mohd; Arshad, Mohd Fadzil; Gholami, Ali

2017-07-01

Water pollution is a global problem. During current study, ammonia, phosphate, phenol, and copper(II) were removed from aqueous solution by subsurface and surface flow constructed wetland. In current investigation, distilled water was polluted with four contaminants including ammonia, phosphate, copper (Cu), and phenol. Response surface methodology and central composite design were applied to optimize pollutant removal during treatment by subsurface flow constructed wetland (SSFCW). Contact time (12 to 80 h) and initial pollutant concentration (20 to 85 mg/L) were selected as independent factors; some upper and lower ranges were also monitored for accuracy. In SSFCW, water hyacinth transplanted in two substrate layers, namely zeolite and cockle shell. SSFCW removed 87.7, 81.4, 74.7, and 54.9% of ammonia, phosphate, Cu, and phenol, respectively, at optimum contact time (64.5 h) and initial pollutant concentration (69.2 mg/L). Aqueous solution was moved to a surface flow constructed wetland (SFCW) after treating via SSFCW at optimum conditions. In SFCW, Typha was transplanted to a fixed powdered substrate layer, including bentonite, zeolite, and cockle shell. SFCW could develop performance of this combined system and could improve elimination efficacy of the four contaminants to 99.99%. So this combined CW showed a good performance in removing pollutants. Graphical abstract Wetlands arrangement for treating aqueous solution in current study.

Enhanced enzymatic hydrolysis of spruce by alkaline pretreatment at low temperature.

PubMed

Zhao, Yulin; Wang, Ying; Zhu, J Y; Ragauskas, Art; Deng, Yulin

2008-04-15

Alkaline pretreatment of spruce at low temperature in both presence and absence of urea was studied. It was found that the enzymatic hydrolysis rate and efficiency can be significantly improved by the pretreatment. At low temperature, the pretreatment chemicals, either NaOH alone or NaOH-urea mixture solution, can slightly remove lignin, hemicelluloses, and cellulose in the lignocellulosic materials, disrupt the connections between hemicelluloses, cellulose, and lignin, and alter the structure of treated biomass to make cellulose more accessible to hydrolysis enzymes. Moreover, the wood fiber bundles could be broken down to small and loose lignocellulosic particles by the chemical treatment. Therefore, the enzymatic hydrolysis efficiency of untreated mechanical fibers can also be remarkably enhanced by NaOH or NaOH/urea solution treatment. The results indicated that, for spruce, up to 70% glucose yield could be obtained for the cold temperature pretreatment (-15 degrees C) using 7% NaOH/12% urea solution, but only 20% and 24% glucose yields were obtained at temperatures of 23 degrees C and 60 degrees C, respectively, when other conditions remained the same. The best condition for the chemical pretreatment regarding this study was 3% NaOH/12% urea, and -15 degrees C. Over 60% glucose conversion was achieved upon this condition. Copyright 2007 Wiley Periodicals, Inc.

Characterization of H3PO4-Treated Rice Husk Adsorbent and Adsorption of Copper(II) from Aqueous Solution

PubMed Central

Zheng, Ru; Zhao, Jiaying; Ma, Fang; Zhang, Yingchao; Meng, Qingjuan

2014-01-01

Rice husk, a surplus agricultural byproduct, was applied to the sorption of copper from aqueous solutions. Chemical modifications by treating rice husk with H3PO4 increased the sorption ability of rice husk for Cu(II). This work investigated the sorption characteristics for Cu(II) and examined the optimum conditions of the sorption processes. The elemental compositions of native rice husk and H3PO4-treated rice husk were determined by X-ray fluorescence (XRF) analysis. The scanning electron microscopic (SEM) analysis was carried out for structural and morphological characteristics of H3PO4-treated rice husk. The surface functional groups (i.e., carbonyl, carboxyl, and hydroxyl) of adsorbent were examined by Fourier Transform Infrared Technique (FT-IR) and contributed to the adsorption for Cu(II). Adsorption isotherm experiments were carried out at room temperature and the data obtained from batch studies fitted well with the Langmuir and Freundlich models with R 2 of 0.999 and 0.9303, respectively. The maximum sorption amount was 17.0358 mg/g at a dosage of 2 g/L after 180 min. The results showed that optimum pH was attained at pH 4.0. The equilibrium data was well represented by the pseudo-second-order kinetics. The percentage removal for Cu(II) approached equilibrium at 180 min with 88.9% removal. PMID:24678507

Effects of irradiation intensity and pH on nutrients release and solids destruction of waste activated sludge using the microwave-enhanced advanced oxidation process.

PubMed

Chan, W I; Liao, P H; Lo, K V

2010-11-01

Using the microwave-enhanced advanced oxidation process (MW/H2O2-AOP), the pH and irradiation intensity on waste activated sludge samples were investigated to provide insight to the athermal effects on nutrients release, solids destruction, particle size distribution and dewaterability, and to demonstrate their interrelationships. Carbonaceous matters and nutrients released into solution depended on the irradiation intensity and time. Higher irradiation levels tended to be more effective in the solubilization of nutrients and had more pronounced effects in the dewaterability of sludge. In terms of particle size distribution, detectable particles increased in size for treatments in acidic conditions, while the dewaterability of treated sludge was improved. In treatments under neutral and alkaline conditions, the particle size range increased, with more small particles formed, thereby significantly deteriorating the dewaterability of sludge treated in alkaline conditions. The best results for the solubilization of nutrients were in alkaline conditions with high irradiation power, but dewaterability of the sludge was compromised. Sludge treatment with the MW/H2O2-AOP in acidic conditions with high irradiation power yielded the best dewaterable sludge and significant nutrient solubilization; therefore, it is the recommended treatment condition for activated sludge.

Development of practical decontamination process for the removal of uranium from gravel.

PubMed

Kim, Ilgook; Kim, Gye-Nam; Kim, Seung-Soo; Choi, Jong-Won

2018-01-01

In this study, a practical decontamination process was developed to remove uranium from gravel using a soil washing method. The effects of critical parameters including particle size, H 2 SO 4 concentration, temperature, and reaction time on uranium removal were evaluated. The optimal condition for two-stage washing of gravel was found to be particle size of 1-2 mm, 1.0 M H 2 SO 4 , temperature of 60°C, and reaction time of 3 h, which satisfied the required uranium concentration for self-disposal. Furthermore, most of the extracted uranium was removed from the waste solution by precipitation, implying that the treated solution can be reused as washing solution. These results clearly demonstrated that our proposed process can be indeed a practical technique to decontaminate uranium-polluted gravel.

Similar solutions for viscous hypersonic flow over a slender three-fourths-power body of revolution

NASA Technical Reports Server (NTRS)

Lin, Chin-Shun

1987-01-01

For hypersonic flow with a shock wave, there is a similar solution consistent throughout the viscous and inviscid layers along a very slender three-fourths-power body of revolution The strong pressure interaction problem can then be treated by the method of similarity. Numerical calculations are performed in the viscous region with the edge pressure distribution known from the inviscid similar solutions. The compressible laminar boundary-layer equations are transformed into a system of ordinary differential equations. The resulting two-point boundary value problem is then solved by the Runge-Kutta method with a modified Newton's method for the corresponding boundary conditions. The effects of wall temperature, mass bleeding, and body transverse curvature are investigated. The induced pressure, displacement thickness, skin friction, and heat transfer due to the previously mentioned parameters are estimated and analyzed.

Application of a novel antimicrobial coating on roast beef for inactivation and inhibition of Listeria monocytogenes during storage.

PubMed

Wang, Luxin; Zhao, Liang; Yuan, Jing; Jin, Tony Z

2015-10-15

The antilisterial efficacy of novel coating solutions made with organic acids, lauric arginate ester, and chitosan was evaluated in a three-stage study on inoculated roast beef for the first time. Ready-to-eat roast beef was specially ordered from the manufacturer. The meat surface was inoculated with five-strain Listeria monocytogenes cocktail inoculums at two different levels, ~3 and 6 Log CFU/cm(2) and treated with the stock solution (HAMS), the 1:5 diluted solution (MAMS), and the 1:10 diluted solution (LAMS) (stage 1). During the 20 min contact time, the antimicrobial coatings reduced the Listeria populations by approximately 0.9-0.3 Log CFU/cm(2). The higher the concentrations of the antimicrobial solution, the better the antilisterial effects were. The treated inoculated beef samples were then stored at 4 °C for 30 days. During storage, Listeria growth inhibition effects were seen. While no growth was seen from the HAMS-treated samples, a 1.6 Log CFU/cm(2) increase was seen for MAMS-treated samples, a 4.6 Log CFU/cm(2) increase was seen for LAMS-treated samples, and a 5.7 Log CFU/cm(2) increase was seen for NoAMS-treated samples on Day 30 (~3 Log CFU/cm(2) inoculation level). In the second stage, the impact of the roast beef storage time on solution's antilisterial effect was evaluated. Results showed that the effect of the antimicrobial solution was dependent on both the initial inoculation levels and storage times. In stage 3, the effect of the antimicrobial solution on roast beef quality was studied with both instrument measurement and sensory evaluation. Minor changes in color, pH, and water activity were found. However, only limited sensory differences were seen between the treated and untreated samples. When panels were able to accurately find color differences between samples, they preferred the treated samples. The findings of this research proved the antilisterial efficacy of the novel antimicrobial solution and showed its potential for being used as a roast beef cut surface coating to control Listeria contamination and for color protection. Copyright © 2015 Elsevier B.V. All rights reserved.

Periodic motions of generalized conservative mechanical systems whose equations of motion contain a large parameter

NASA Astrophysics Data System (ADS)

Sazonov, V. V.

An analysis is made of a generalized conservative mechanical system whose equations of motion contain a large parameter characterizing local forces acting along certain generalized coordinates. It is shown that the equations have periodic solutions which are close to periodic solutions to the corresponding degenerate equations. As an example, the periodic motions of a satellite with respect to its center of mass due to gravitational and restoring aerodynamic moments are examined for the case where the aerodynamic moment is much larger than the gravitational moment. Such motions can be treated as nominal unperturbed motions of a satellite under conditions of single-axis aerodynamic attitude control.

A unified perspective on preferential solvation and adsorption based on inhomogeneous solvation theory

NASA Astrophysics Data System (ADS)

Shimizu, Seishi; Matubayasi, Nobuyuki

2018-02-01

How cosolvents affects solvation has been revealed through the independent determination of solute-solvent and solute-cosolvent interactions guaranteed by the phase rule. Based on the first principles of inhomogeneous solvation theory, we present here a general matrix theory encompassing both preferential solvation and surface adsorption. The central role of the stability conditions, that govern how many excess numbers (surface excesses) are independently determinable, have been clarified from the first principles. The advantage of the inhomogeneous approach has been demonstrated to be in its ease in treating solvation and adsorption in a unified manner, while its disadvantage, for example in membrane dialysis experiments, can be overcome by the inhomogeneous-homogeneous conversion.

Application of shifted Jacobi pseudospectral method for solving (in)finite-horizon min-max optimal control problems with uncertainty

NASA Astrophysics Data System (ADS)

Nikooeinejad, Z.; Delavarkhalafi, A.; Heydari, M.

2018-03-01

The difficulty of solving the min-max optimal control problems (M-MOCPs) with uncertainty using generalised Euler-Lagrange equations is caused by the combination of split boundary conditions, nonlinear differential equations and the manner in which the final time is treated. In this investigation, the shifted Jacobi pseudospectral method (SJPM) as a numerical technique for solving two-point boundary value problems (TPBVPs) in M-MOCPs for several boundary states is proposed. At first, a novel framework of approximate solutions which satisfied the split boundary conditions automatically for various boundary states is presented. Then, by applying the generalised Euler-Lagrange equations and expanding the required approximate solutions as elements of shifted Jacobi polynomials, finding a solution of TPBVPs in nonlinear M-MOCPs with uncertainty is reduced to the solution of a system of algebraic equations. Moreover, the Jacobi polynomials are particularly useful for boundary value problems in unbounded domain, which allow us to solve infinite- as well as finite and free final time problems by domain truncation method. Some numerical examples are given to demonstrate the accuracy and efficiency of the proposed method. A comparative study between the proposed method and other existing methods shows that the SJPM is simple and accurate.

PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS

DOEpatents

Carter, J.M.; Kamen, M.D.

1958-10-14

A process is presented for recovering uranium values from UCl/sub 4/ deposits formed on calutrons. Such deposits are removed from the calutron parts by an aqueous wash solution which then contains the uranium values in addition to the following impurities: Ni, Cu, Fe, and Cr. This impurity bearing wash solution is treated with an oxidizing agent, and the oxidized solution is then treated with ammonia in order to precipitate the uranium as ammonium diuranate. The metal impurities of iron and chromium, which form insoluble hydroxides, are precipitated along with the uranium values. The precipitate is separated from the solution, dissolved in acid, and the solution again treated with ammonia and ammonium carbonate, which results in the precipitation of the metal impurities as hydroxides while the uranium values remain in solution.

PERITONEAL DIALYSIS FOR AKI IN CAMEROON: COMMERCIAL VS LOCALLY-MADE SOLUTIONS.

PubMed

Palmer, Dennis; Lawton, William J; Barrier, Charles; Fine, Bd; Hemphill, Hayden; Nyah, Norah; Kinne, Virginie; Ringnwi, Njaprim I; Yong, Genevive; Neufeldt, Amy L; Mambou, Yves Mitterand M; Finkelstein, Fredric O; Krahn, Thomas

2018-05-23

Acute kidney injury (AKI) is common in low- and middle-income countries, and is associated with a high mortality. The high mortality rate is in large part due to the inability to perform dialysis in resource-limited settings. Due to significant cost advantages, peritoneal dialysis (PD) has been used to treat AKI in these settings. The costs, however, remain high when commercial solutions are used. This is a retrospective cohort study of the outcome, and of the peritonitis rates, of patients with AKI treated with either commercially manufactured PD solutions or locally-made PD solutions. A program to treat AKI with PD was started at Mbingo Baptist Hospital in Cameroon. Between May 2013 and January 2015, solutions and connection sets were provided by the Saving Young Lives Program. From January 2015 through March 2017, solutions were locally produced and available tubing was used. Mortality in hospitalized AKI patients was 28% during the period when commercial solutions and tubing were utilized, and 33% when locally produced solutions and available tubing were utilized. In both groups, peritonitis occurred in 16% of treatment courses. Locally produced PD solutions, used with locally available tubing, were used to treat AKI with PD. The mortality and peritonitis rates were similar whether locally produced or commercial supplies were used.

Corrosion behavior of heat-treated intermetallic titanium-nickel in hydrochloric acid solutions

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

Starosvetsky, D.; Khaselev, O.; Yahalom, J.

1998-07-01

Samples of 45% Ti-55% Ni alloy (Ti-Ni) were heat-treated in air at 450 C, and their anodic behavior in 0.3 M, 1 M, 2 M, and 4 M hydrochloric acid (HCl) solutions was studied. In 0.3 M HCl, heat-treated Ti-Ni was passive, and very low anodic currents were observed. In 1 M and 2 M HCl, heat-treated Ti-Ni was dissolved actively, while heat-treated and surface-ground Ti-Ni became passive. The effect was explained by selective oxidation of Ti-Ni and formation of a layered structure on its surface with discontinuous titanium oxide and a nickel-enriched zone underneath. The latter was dissolved inmore » the HCl solutions, thus accelerating failure of the Ti-Ni samples. In 4 M HCl, heat-treated and heat-treated/ground samples were dissolved readily.« less

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

Tadayyon, Ghazal; Mazinani, Mohammad; Guo, Yina

Martensitic evolution in Ti-rich NiTi alloy, Ti50.5Ni49.5, has been investigated as a function of annealing, solution treatment and a combination thereof and a detailed electron microscopic investigation carried out. Self-accommodated martensite plates resulted in all heat treated samples. Martensitic < 011 > type II twins, which are common in NiTi shape memory alloys, was found in both as-received and heat-treated samples. Solution treated samples, additionally, showed {11-1} type I twinning was also found in samples that have been annealed after solution-treatment. Another common feature of the microstructure in both as-received and heat treated samples is the formation of Ti{sub 2}Nimore » precipitates. The size, number and dispersions of these precipitates can be controlled by resorting to a suitable heat treatment e.g. solution treatment.« less

Degradation of Active Brilliant Red X-3B by a microwave discharge electrodeless lamp in the presence of activated carbon.

PubMed

Fu, Jie; Wen, Teng; Wang, Qing; Zhang, Xue-Wei; Zeng, Qing-Fu; An, Shu-Qing; Zhu, Hai-Liang

2010-06-01

Degradation of Active Brilliant Red X-3B (X-3B) in aqueous solution by a microwave discharge electrodeless lamp (MDEL) in the presence of activated carbon was investigated. The preliminary results proved this method could effectively degrade X-3B in aqueous solution. The removal percentages of colour and chemical oxygen demand were up to approximately 99% and 66%, respectively, at the conditions of 0.8 g/L dye concentration, 20 g/L activated carbon, pH 7.0 and 8 min microwave irradiation time. The degradation basically belonged to first-order reaction kinetics and its rate constant was 0.42 min(-1). No aromatic organics were detected in the final treated solution, indicating that the mineralization was relatively complete. By studying the change in solution properties, it could be concluded that MDEL-assisted oxidation was the dominant reaction mechanism. In addition, the influence of operational parameters and reuse of activated carbon were also discussed.

Development Of The Prototype Space Non-Foam Membrane Bioreactor

NASA Astrophysics Data System (ADS)

Guo, S.; Xi, W.; Liu, X.

The essential method of making Controlled Ecological Life Support System (CELSS) operate and regenerate efficiently, is to transform and utilize the recycleable materials in the system rapidly. Currently, it is generally recognized that the fundamental way of achieving the goal is to utilize micro-biotechnology. Exactly based on this thinking, a Groundbased Prototype of Space Waste-treating-microbially Facility(GPSWF) was developed in our laboratory, with the purpose of transforming biologically-degradeable waste including inedible plant biomass into plant nutrient solution for attaining future regenerated utilization of materials in the space environment. The facility holds the automatic measurement and control systems of temperature, pH and dissolved oxygen (DO) in treated solution, and the systems of non-foam membrane oxygen provision and post-treated liquid collection. The experimental results showed that the facility could maintain a stable operating state; the pH and DO in the liquid were controlled automatically and precisely; the oxygen in the liquid was non-foamedly provided by membrane technology; the plant inedible biomass could be completely degraded by three species of microbes selected; the decreasing rates of total organic carbon(TOC) and chemical oxygen demand(COD) reached to 92.1% and 95.5% respectively; the post-treated liquid could be automatically drained and collected; the plants could grow almost normally when the post-treated liquid was used as nutrient liquid. Therefore, it can be concluded that the facility possesses a reasonably-designed structure, and its working principle is nearly able to meet the condition of space microgravity environment. So it's hopeful to be applied in space for biological degradation of materials after further improvement.

Solution-processed lithium-doped zinc oxide thin-film transistors at low temperatures between 100 and 300 °C

NASA Astrophysics Data System (ADS)

Liu, Fangmei; Qian, Chuan; Sun, Jia; Liu, Peng; Huang, Yulan; Gao, Yongli; Yang, Junliang

2016-04-01

Lithium-doped zinc oxide (Li-ZnO) thin-film transistors (TFTs) were fabricated by solution process at the low temperatures ranged from 100 to 300 °C. Li-ZnO TFTs fabricated at 300 °C under nitrogen condition showed a mobility of 1.2 cm2/Vs. Most importantly, the mobility of Li-ZnO TFT devices fabricated at 100 °C could be increased significantly from 0.08 to 0.4 cm2/Vs by using double spin-coated and UV irradiation-treated Li-ZnO film, and the on-/off-current ratio is in the order of 106. Notably, the XPS analyses proved that the performance improvement was originated from the chemical composition or stoichiometry evolution, in which the hydroxide was converted into metal oxide and accelerated the formation of the oxygen vacancies. Furthermore, low-voltage operating Li-ZnO TFTs were demonstrated by using a high-capacitance ion gel gate dielectrics. The Li-ZnO TFTs with an operating voltage as low as 2 V exhibited the carrier mobilities of 2.1 and 0.65 cm2/Vs for the devices treated at 300 and 100 °C, respectively. The low-temperature, solution-processed Li-ZnO TFTs showed greatly potential applications in flexible displays, smart label, and sensors.

Effect of cryogenic treatment on the fracture toughness of aircraft aluminum alloy 7075

NASA Astrophysics Data System (ADS)

Ermishkin, V. A.; Soloveva, Y. B.

2018-04-01

Influence of three types of the treatment on fracture toughness of the Al-7075 alloy was investigated in this study. Commercial Al-7075 alloy in the solid solution heat-treated condition was processed by hardening with post-cryogenic deformation treatment and PVD deposition titanium and copper coatings. The fracture toughness was estimated with using macroscopic and microscopic approaches. The conditions for the coincidence of the fracture toughness estimates between brittle fracture mechanics and the photometric analysis of structural images (PHASI) methods were achieved. The highest fracture toughness was obtained by applying hardening, cryogenic compression, ageing and deposition of the Ti-coating, leading to dispersion particles precipitation.

Numerical Solution of the Flow of a Perfect Gas Over A Circular Cylinder at Infinite Mach Number

NASA Technical Reports Server (NTRS)

Hamaker, Frank M.

1959-01-01

A solution for the two-dimensional flow of an inviscid perfect gas over a circular cylinder at infinite Mach number is obtained by numerical methods of analysis. Nonisentropic conditions of curved shock waves and vorticity are included in the solution. The analysis is divided into two distinct regions, the subsonic region which is analyzed by the relaxation method of Southwell and the supersonic region which was treated by the method of characteristics. Both these methods of analysis are inapplicable on the sonic line which is therefore considered separately. The shapes of the sonic line and the shock wave are obtained by iteration techniques. The striking result of the solution is the strong curvature of the sonic line and of the other lines of constant Mach number. Because of this the influence of the supersonic flow on the sonic line is negligible. On comparison with Newtonian flow methods, it is found that the approximate methods show a larger variation of surface pressure than is given by the present solution.

A spline-based parameter estimation technique for static models of elastic structures

NASA Technical Reports Server (NTRS)

Dutt, P.; Taasan, S.

1986-01-01

The problem of identifying the spatially varying coefficient of elasticity using an observed solution to the forward problem is considered. Under appropriate conditions this problem can be treated as a first order hyperbolic equation in the unknown coefficient. Some continuous dependence results are developed for this problem and a spline-based technique is proposed for approximating the unknown coefficient, based on these results. The convergence of the numerical scheme is established and error estimates obtained.

Improved and Cost Effective Machining Techniques for Tracked Combat Vehicle Parts

DTIC Science & Technology

1983-10-01

steel is shown in Figure 7-7 and consists of tempered marten- site. Three of the alloys which are used in the gas turbine engine are cast 17 - 4PH ...stainless steel, Inconel 718 and Inconel 713. The 17 - 4PH stainless steel was machined in the solution treated and aged condition. The microstructure as shown...SECURITY CLASS. (of thia report) ISa. DECLASSIFICATION/DOWNGRADING SCHEDULE 16. DISTRIBUTION STATEMENT (of thie Report) 17 . DISTRIBUTION STATEMENT (of

Onychoprotothecosis: report of the first case in Brazil.

PubMed

Zaitz, Clarisse; Miranda Godoy, Andrea; de Sousa, Valéria Maria; Ruiz, Ligia Rangel B; Masada, Andréa S; Nobre, Márcia Valéria; Santos, Ana Regina Alencar; Marques, Ana Cristina; Muramatu, Laura Hitomi; Arrigada, Giovanna Letícia Hernandez; Heins-Vaccari, Elisabeth Maria; Martins, José Eduardo Costa

2006-09-01

The present report describes a case of onychoprotothecosis caused by Prototheca wickerhamii in a nonimmunocompromized female. Dermatological examination showed yellowish discoloration of the left and right forefinger nails, showing onicolysis and hyperkeratosis. The repeated isolation of the algae Prototheca (organisms morula-like) as well as the repeated culture in media, Sabouraud agar, confirmed the diagnosis. The patient was successfully treated with tioconazol 1% topic solution. The aim of this paper was to present a rare condition.

The kinetics, current efficiency, and power consumption of electrochemical dye decolorization by BD-NCD film electrode

NASA Astrophysics Data System (ADS)

Nurhayati, Ervin; Juang, Yaju; Huang, Chihpin

2017-06-01

Diamond film electrode has been known as a material with very wide potential window for water electrolysis which leads to its applicability in numerous electrochemical processes. Its capability to produce hydroxyl radicals, a very strong oxidants, prompts its popular application in wastewater treatment. Batch and batch recirculation reactor were applied to perform bulk electrolysis experiments to investigate the kinetics of dye decolorization under different operation conditions, such as pH, active species, and current density. Furthermore, COD degradation data from batch recirculation reactor operation was used as the basis for the calculation of current efficiency and power consumption in the decolorization process. The kinetics of decolorization process using boron-doped nanocrystalline diamond (BD-NCD) film electrode revealed that acidic condition is favored for the dye degradation, and the presence of chloride ion in the solution was found to be more advantageous than sulfate active species, as evidenced by the higher reaction rate constants. Applying different current density of 10, 20 and 30 mA cm-2, it was found that the higher the current density the faster the decolorization rate. General current efficiency achieved after nearly total decolorization and 80% COD removal in batch recirculation reactor was around 74%, with specific power consumption of 4.4 kWh m-3 (in terms of volume of solution treated) or 145 kWh kg-1(in terms of kg COD treated).

Effect of lawsonia innermis (linn) leaves ethanolic extract on blood glucose and malondialdehyde level in alloxan-induced diabetic rats

NASA Astrophysics Data System (ADS)

Indah Sari, Mutiara; Ilyas, Syafruddin; Widyawati, Tri; Anjelir Antika, Maya

2018-03-01

The case of diabetes mellitus (DM) tends to increase worldwide. DM triggers the oxidative stress condition that caused by the increasing of free radical. The present study was conducted to evaluate the effect of giving ethanolic extract of Lawsonia inermis (Linn) leaves to the glucose and malondialdehyde (MDA) level in alloxan-induced diabetic Wistar male rats. The powder of dry leaves of L.inermis was macerated in ethanol 96% to obtain ethanolic extract (LLEE).Thirty five of rats were divided into five groups, ie. K (normal and given 0.9% NaCl solution ), P1-P4 were induced using alloxan (120 mg/kg) intraperitoneally to get diabetic condition. Diabetic rats then were treated as follows: P1 (given 0.9% NaCl solution) P2 (LLEE (200 mg/kg BW), P3 (LLEE (400 mg/kg BW)), P4 ( LLEE (600 mg/kg BW)). All groups were treated for 28 days. The fasting blood glucose levels were measured at day 1, 7, 14, 21, 28 whereas MDA levels were measured at the end of treatment. The result showed that LLEE improved blood glucose level (BGLs) of alloxan-induced diabetic rats significantly (p< 0.001) at 29th day. However, LLEE could not affect the MDA level (p > 0.5). The study concluded that LLEE have antihyperglycemic properties.

[Kinetic theory and boundary conditions for highly inelastic spheres]. Quarterly progress report, April 1, 1993--June 30, 1993

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

Richman, M.

1993-12-31

In this quarter, a kinetic theory was employed to set up the boundary value problem for steady, fully developed, gravity-driven flows of identical, smooth, highly inelastic spheres down bumpy inclines. The solid fraction, mean velocity, and components of the full second moment of fluctuation velocity were treated as mean fields. In addition to the balance equations for mass and momentum, the balance of the full second moment of fluctuation velocity was treated as an equation that must be satisfied by the mean fields. However, in order to simplify the resulting boundary value problem, fluxes of second moments in its isotropicmore » piece only were retained. The constitutive relations for the stresses and collisional source of second moment depend explicitly on the second moment of fluctuation velocity, and the constitutive relation for the energy flux depends on gradients of granular temperature, solid fraction, and components of the second moment. The boundary conditions require that the flows are free of stress and energy flux at their tops, and that momentum and energy are balanced at the bumpy base. The details of the boundary value problem are provided. In the next quarter, a solution procedure will be developed, and it will be employed to obtain sample numerical solutions to the boundary value problem described here.« less

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

Tan, Y.B.; Yang, L.H.; Duan, J.L.

The kinetics of the β → α phase transformation in the 47Zr–45Ti–5Al–3V (wt.%) alloy with different initial β grain sizes under isothermal conditions was investigated by X-ray diffraction. The results showed that the volume fraction of α phase first increased with increasing aging time, and then reached an equilibrium value. The equilibrium value of α phase decreased with increased aging temperature. At the same aging temperature and time, the volume fraction of α phase in the 47Zr–45Ti–5Al–3V alloy solution-treated at 850 °C was higher than at 1050 °C, and the size of α phase in the 47Zr–45Ti–5Al–3V alloy solution-treated atmore » 850 °C was larger than that at 1050 °C. The kinetics of the β → α phase transformation was modeled under isothermal conditions in the theoretical frame of the Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory. The Avrami index (n) increased with increasing aging temperature, while the reaction rate constant (k) decreased. - Highlights: • The kinetics of the β → α phase transformation in the ZrTiAlV alloy was investigated. • The volume fraction of α phase first increased and then reached an equilibrium value. • The kinetics of the β → α phase transformation was modeled by the JMAK theory. • The n increased with increasing aging temperature, while the k decreased.« less

Preparation and characterization of non-crystalline granular starch and corresponding carboxymethyl starch.

PubMed

Zhang, Bao; Li, Xiaomin; Xie, Qiutao; Tao, Han; Wang, Wu; Chen, Han-Qing

2017-10-01

Native corn starch slurried in 50% ethanol solution was treated at 60°C, 70°C, 80°C, and 85°C, respectively. The resultant starches were investigated by polarized microscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and X-ray diffractometry (XRD). The Maltese cross of ethanol-heating treated starch gradually weaken with increasing temperature and completely disappeared at 85°C. SEM data indicated the treated granular exhibited a rougher surface with more pores and grooves than native starch granular, but the shape of the treated starch was still intact. DSC and XRD data confirmed ethanol-heating treated starch changed from crystalline to non-crystalline structure at 85°C. The highest degree of substitution (DS) and corresponding reaction efficiency (RE) for the carboxymethylation of native starch were 0.66 and 36.7%, respectively, while the corresponding DS and RE for non-crystalline granular starches increased by 0.29 and 16.1% at the same reaction condition, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Heat Treatment on Liquation Cracking in Continuous Fiber and Pulsed Nd:YAG Laser Welding of HASTELLOY X Alloy

NASA Astrophysics Data System (ADS)

Pakniat, M.; Ghaini, F. Malek; Torkamany, M. J.

2017-11-01

Laser welding of HASTELLOY X is highly feasible; however, hot cracking can be a matter of concern. The objective of this study is to assess the effect of solution heat treatment on susceptibility to liquation cracking in welding of a 2-mm-thick HASTELLOY X plate. In addition, Nd-YAG pulsed laser (400 W) and continuous wave (CW) fiber laser (600 W) were compared with each other in this respect. Results revealed that performing the prewelding solution heat treatment reduces the tendency for occurrence of liquation cracking. Furthermore, it was established that by increasing pulse frequency, there was a significant reduction in the tendency for liquation cracking. With CW laser welding of HASTELLOY X in the solution-heat-treated condition, the tendency for heat-affected zone (HAZ) cracking was found to be minimized.

Enhancing uranium uptake by amidoxime adsorbent in seawater: An investigation for optimum alkaline conditioning parameters

DOE PAGES

Das, Sadananda; Tsouris, Costas; Zhang, Chenxi; ...

2015-09-07

A high-surface-area polyethylene-fiber adsorbent (AF160-2) has been developed at the Oak Ridge National Laboratory by radiation-induced graft polymerization of acrylonitrile and itaconic acid. The grafted nitriles were converted to amidoxime groups by treating with hydroxylamine. The amidoximated adsorbents were then conditioned with potassium hydroxide (KOH) by varying different reaction parameters such as KOH concentration (0.2, 0.44, and 0.6 M), duration (1, 2, and 3 h), and temperature (60, 70, and 80 °C). Adsorbent screening was then performed with simulated seawater solutions containing sodium chloride and sodium bicarbonate, at concentrations found in seawater, and uranium nitrate at a uranium concentration ofmore » ~7–8 ppm and pH 8. Fourier transform infrared spectroscopy and solid-state NMR analyses indicated that a fraction of amidoxime groups was hydrolyzed to carboxylate during KOH conditioning. The uranium adsorption capacity in the simulated seawater screening solution gradually increased with conditioning time and temperature for all KOH concentrations. It was also observed that the adsorption capacity increased with an increase in concentration of KOH for all the conditioning times and temperatures. AF160-2 adsorbent samples were also tested with natural seawater using flow-through experiments to determine uranium adsorption capacity with varying KOH conditioning time and temperature. Based on uranium loading capacity values of several AF160-2 samples, it was observed that changing KOH conditioning time from 3 to 1 h at 60, 70, and 80 °C resulted in an increase of the uranium loading capacity in seawater, which did not follow the trend found in laboratory screening with stimulated solutions. Longer KOH conditioning times lead to significantly higher uptake of divalent metal ions, such as calcium and magnesium, which is a result of amidoxime conversion into less selective carboxylate. The scanning electron microscopy showed that long conditioning times may also lead to adsorbent degradation.« less

Enhancing Uranium Uptake by Amidoxime Adsorbent in Seawater: An investigation for optimum alkaline conditioning parameters

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

Das, S.; Tsouris, Constantinos; Zhang, C.

2016-04-20

A high-surface-area polyethylene-fiber adsorbent (AF160-2) has been developed at the Oak Ridge National Laboratory (ORNL) by radiation-induced graft polymerization of acrylonitrile and itaconic acid. The grafted nitriles were converted to amidoxime groups by treating with hydroxylamine. The amidoximated adsorbents were then conditioned with potassium hydroxide (KOH) by varying different reaction parameters such as KOH concentration (0.2, 0.44, and 0.6 M), duration (1, 2, and 3 h), and temperature (60, 70, and 80 ºC). Adsorbent screening was then performed with simulated seawater solutions containing sodium chloride and sodium bicarbonate, at concentrations found in seawater, and uranium nitrate at a uranium concentrationmore » of ~ 7-8 ppm and pH 8. FTIR and solid state NMR indicated that a fraction of amidoxime groups was hydrolyzed to carboxylate during KOH conditioning. The uranium adsorption capacity in the simulated seawater screening solution gradually increased with conditioning time and temperature for all KOH concentrations. It was also observed that the adsorption capacity increased with an increase in concentration of KOH for all the conditioning times and temperatures. AF160-2 adsorbent samples were also tested with natural seawater using flow-through experiments to determine uranium adsorption capacity with varying KOH conditioning time and temperature. Based on uranium loading capacity values of several AF160-2 samples, it was observed that changing KOH conditioning time from 3 to 1 h at 60, 70, and 80 ºC resulted in increase of the uranium loading capacity in seawater, which did not follow the trend found in laboratory screening with stimulated solutions. Longer KOH conditioning times lead to significantly higher uptake of divalent metal ions, such as calcium and magnesium, which is a result of amidoxime conversion into less selective carboxylate. Scanning electron microscopy showed that long conditioning times may also lead to adsorbent degradation« less

In Situ Synthesis of Gold Nanoparticles on Wool Powder and Their Catalytic Application.

PubMed

Tang, Bin; Zhou, Xu; Zeng, Tian; Lin, Xia; Zhou, Ji; Ye, Yong; Wang, Xungai

2017-03-15

Gold nanoparticles (AuNPs) were synthesized in situ on wool powder (WP) under heating conditions. Wool powder not only reduced Au ions to AuNPs, but also provided a support for as-synthesized AuNPs. WPs were treated under different concentrations of Au ions, and corresponding optical features and morphologies of the treated WPs were investigated by UV-VIS diffuse reflectance absorption spectroscopy and scanning electron microscopy (SEM). X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscope (TEM) were also employed to characterize the WP treated with AuNPs. The results demonstrate that AuNPs were produced in the presence of WP and distributed over the wool particles. The porous structure led to the synthesis of AuNPs in the internal parts of WP. Acid conditions and high temperature facilitated the synthesis of AuNPs by WP in aqueous solution. The reducibility of wool was improved after being converted to powder from fibers, due to exposure of more active groups. Moreover, the obtained AuNP-WP complexes showed significant catalytic activity to accelerate the reduction reaction of 4-nitrophenol (4-NP) by sodium borohydride (NaBH₄).

The use of raw and acid-pretreated bivalve mollusk shells to remove metals from aqueous solutions.

PubMed

Liu, Yang; Sun, Changbin; Xu, Jin; Li, Youzhi

2009-08-30

Heavy metal removal from industrial wastewater is not only to protect living organisms in the environment but also to conserve resources such as metals and water by enabling their reuse. To overcome the disadvantage of high cost and secondary pollution by the conventional physico-chemical treatment techniques, environmentally benign and low-cost adsorbents are in demand. In this study, the use of raw and acid-pretreated bivalve mollusk shells (BMSs) to remove metals from aqueous solutions with single or mixed metal was evaluated at different BMSs doses, pH and temperatures in batch shaking experiments in laboratory conditions. When the BMSs were used to treat CuSO(4)x5H(2)O solution, the copper sorption capacities of the raw and acid-pretreated BMSs were approximately 38.93 mg/g and 138.95 mg/g, respectively. The copper removal efficiency (CRE) of the raw BMSs became greatly enhanced with increasing initial pH, reaching 99.51% at the initial pH 5. Conversely, the CRE of the acid-pretreated BMSs was maintained at 99.48-99.52% throughout the pH range of 1-5. Furthermore, the CRE values of the raw and acid-pretreated BMSs were not greatly changed when the temperature was varied from 15 degrees C to 40 degrees C. In addition, the CRE value of the raw BMSs was maintained for 12 cycles of sorption-desorption with a CRE of 98.4% being observed in the final cycle. Finally, when the BMSs were used to treat electroplating wastewater, the removal efficiencies (REs) of the raw BMSs were 99.97%, 98.99% and 87% for Fe, Zn and Cu, respectively, whereas the REs of the acid-pretreated BMSs were 99.98%, 99.43% and 92.13%, respectively. Ion exchange experiments revealed that one of mechanisms for metal sorption by the BMSs from aqueous solution is related to ion exchange, especially between the metal ions in the treated solution and Ca(2+) from BMSs. Infrared absorbance spectra analysis indicated that the acid pretreatment led to occurrence of the groups (i.e. -OH, -NH, C=O and S=O) of negative charge in treated BMSs. Scanning electron microscopy revealed that acid pretreatment enabled the used BMSs to form the flake-shaped structure with smooth surfaces that can supply a better interface for binding metal ions.

Design and stability study of an oral solution of amlodipine besylate for pediatric patients.

PubMed

van der Vossen, A C; van der Velde, I; Smeets, O S N M; Postma, D J; Vermes, A; Koch, B C P; Vulto, A G; Hanff, L M

2016-09-20

Amlodipine is an antihypertensive agent recommended for the management of hypertension in children and adolescents. The commercially available tablets of 5 and 10mg do not provide the necessary flexibility in dosing needed for treating children. Our goal was to develop a pediatric oral solution of amlodipine, using a robust manufacturing process suitable for ex-tempora and larger scale production. The parameters API and preservative content, related substances, appearance and pH were studied under four different storage conditions. Samples were analyzed up to 12months. Microbiological quality was studied in an 18-week in-use test based on a two-times daily dosing schedule. The stability of the formulation was influenced by storage conditions and composition. A formulation containing amlodipine besylate, sucrose syrup and methyl paraben remained physically stable for 12months at 4°C with no loss of amlodipine content. Related substances increased during the study but remained below 0.5%. In-use stability was proven up to 18weeks. Storage under refrigerated conditions was necessary to prevent precipitation and to obtain an acceptable shelf-life. In conclusion, we have developed and validated an amlodipine oral solution, suitable for the pediatric population. This liquid formulation is preferred over manipulated commercial dosage forms or non-standardized extemporaneously compounded formulations. Copyright © 2016 Elsevier B.V. All rights reserved.

Specific stimulated uptake of acetylcholine by Torpedo electric organ synaptic vesicles.

PubMed Central

Parsons, S M; Koenigsberger, R

1980-01-01

The specificity of acetylcholine uptake by synaptic vesicles isolated from the electric organ of Torpedo californica was studied. In the absence of cofactors, [3H]acetylcholine was taken up identically to[14C]choline in the same solution (passive uptake), and the equilibrium concentration achieved inside the vesicles was equal to the concentration outside. In the presence of MgATP, [3H]acetylcholine and [14C]choline in the same solution were taken up identically, except only about half as much of each was taken up (suppressed uptake). [3H]Acetylcholine uptake was stimulated by MgATP and HCO3- about 4-fold relative to suppressed uptake, for a net concentrative uptake of about 2:1 (stimulated uptake). Uptake of [14C]choline in the same solution remained at the suppressed level. [3H]Acetylcholine taken up under stimulated conditions migrated with vesicles containing [14C]mannitol on analytical glycerol density gradients during centrifugation. Vesicle were treated with nine protein modification reagents under mild conditions. Two reagents had no effect on, dithiothreitol potentiated, and six reagents strongly inhibited subsequent stimulated uptake of [3H]acetylcholine. The results indicate that uptake of acetylcholine is conditionally specific for the transported substrate, is carried out by the synaptic vesicles rather than a contaminant of the preparation, and requires a functional protein system containing a critical sulfhydryl group. PMID:6934549

Immobilization of Rose Waste Biomass for Uptake of Pb(II) from Aqueous Solutions

PubMed Central

Ansari, Tariq Mahmood; Hanif, Muhammad Asif; Mahmood, Abida; Ijaz, Uzma; Khan, Muhammad Aslam; Nadeem, Raziya; Ali, Muhammad

2011-01-01

Rosa centifolia and Rosa gruss an teplitz distillation waste biomass was immobilized using sodium alginate for Pb(II) uptake from aqueous solutions under varied experimental conditions. The maximum Pb(II) adsorption occurred at pH 5. Immobilized rose waste biomasses were modified physically and chemically to enhance Pb(II) removal. The Langmuir sorption isotherm and pseudo-second-order kinetic models fitted well to the adsorption data of Pb(II) by immobilized Rosa centifolia and Rosa gruss an teplitz. The adsorbed metal is recovered by treating immobilized biomass with different chemical reagents (H2SO4, HCl and H3PO4) and maximum Pb(II) recovered when treated with sulphuric acid (95.67%). The presence of cometals Na, Ca(II), Al(III), Cr(III), Cr(VI), and Cu(II), reduced Pb(II) adsorption on Rosa centifolia and Rosa gruss an teplitz waste biomass. It can be concluded from the results of the present study that rose waste can be effectively used for the uptake of Pb(II) from aqueous streams. PMID:21350666

In situ detection of microbial respiration in soils and salt flats. [Nevada desert

NASA Technical Reports Server (NTRS)

Tew, R. W.

1973-01-01

Increase in CO2 partial pressures over a desert soil treated with casamino-acids glucose solution correlated with bacterial growth. Few or no increases in numbers of bacteria or CO2 concentrations were noted in similar plots treated with water only or receiving no treatment. Growth in the soil appeared to be severely nutrient limited during the 10 day experiment. Especially rapid growth took place between the third and fifth day, when temperatures ranged from 0 deg. (night) to a maximum of 17.4 deg. (day). Under the conditions of the experiment, intermittent CO2 assay was an insensitive indicator of growth, possibly because of restiction of gas escape by the desert pavement or solution, exchange, or precipitation of carbonate, but more likely because of inefficient sealing of hoods to and below the soil surface. CO2 assay was unable to detect microbial successions. The unpredictable course of these successions, plus unpredictable relative retentions mitigates against assay of organic gases as reliable in situ detection of microbial activity, except perhaps in very alkaline environments such as Owens Lake salts.

Investigation of Cr(VI) adsorption onto chemically treated Helianthus annuus: optimization using response surface methodology.

PubMed

Jain, Monika; Garg, V K; Kadirvelu, K

2011-01-01

In the present study, chemically treated Helianthus annuus flowers (SHC) were used to optimize the removal efficiency for Cr(VI) by applying Response Surface Methodological approach. The surface structure of SHC was analyzed by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Analysis (EDX). Batch mode experiments were also carried out to assess the adsorption equilibrium in aqueous solution. The adsorption capacity (qe) was found to be 7.2 mg/g. The effect of three parameters, that is pH of the solution (2.0-7.0), initial concentration (10-70 mg/L) and adsorbent dose (0.05-0.5 g/100 mL) was studied for the removal of Cr(VI) by SHC. Box-Behnken model was used as an experimental design. The optimum pH, adsorbent dose and initial Cr(VI) concentration were found to be 2.0, 5.0 g/L and 40 mg/L, respectively. Under these conditions, removal efficiency of Cr(VI) was found to be 90.8%. Copyright © 2010 Elsevier Ltd. All rights reserved.

Center-Within-Trial Versus Trial-Level Evaluation of Surrogate Endpoints.

PubMed

Renfro, Lindsay A; Shi, Qian; Xue, Yuan; Li, Junlong; Shang, Hongwei; Sargent, Daniel J

2014-10-01

Evaluation of candidate surrogate endpoints using individual patient data from multiple clinical trials is considered the gold standard approach to validate surrogates at both patient and trial levels. However, this approach assumes the availability of patient-level data from a relatively large collection of similar trials, which may not be possible to achieve for a given disease application. One common solution to the problem of too few similar trials involves performing trial-level surrogacy analyses on trial sub-units (e.g., centers within trials), thereby artificially increasing the trial-level sample size for feasibility of the multi-trial analysis. To date, the practical impact of treating trial sub-units (centers) identically to trials in multi-trial surrogacy analyses remains unexplored, and conditions under which this ad hoc solution may in fact be reasonable have not been identified. We perform a simulation study to identify such conditions, and demonstrate practical implications using a multi-trial dataset of patients with early stage colon cancer.

Adsorption of Ni(II) onto Chemically Modified Spent Grated Coconut (Cocos Nucifera)

NASA Astrophysics Data System (ADS)

Hamzah, F. I.; Khalid, K.; Hanafiah, M. A. K. M.

2017-06-01

A new adsorbent of plant waste origin from coconut processing food factory was explored for removing Ni(II) from aqueous solutions. Several parameters such as pH, dosage, concentration and contact time were studied to obtain optimum conditions for treatment of Ni(II) contaminated wastewater. Spent grated coconut (Cocos nucifera) treated with sulfuric acid (SSGC) showed good adsorption capacity for Ni(II) ion. The amount adsorbed was affected by solution pH with the highest value achieved at pH 5. Other optimum conditions found were; dosage of 0.02 g, and 60 min of equilibrium time. Ni(II) adsorption obeyed the pseudo-second order kinetic model which suggested that chemisorption mechanism occurred in the adsorption process. The equilibrium data presented a better fitting to the Langmuir isotherm model, an indication that monolayer adsorption occurred onto a homogeneous surface. The maximum adsorption capacity, qmax was 97.09 mg g-1, thus SSGC can be classified as good and comparable with other plant waste adsorbents.

CO/sub 2/ absorption into aqueous MDEA and MDEA/MEA solutions

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

Critchfield, J.; Rochelle, G.T.

1987-01-01

The rate of absorption of CO/sub 2/ into 2 molal MDEA was measured by following solution composition in a stirred-cell batch reactor. The conditions investigated were 9.5 - 62/sup 0/C at a nominal CO/sub 2/ pressure of 1 atm. The data were modelled with a combined mass transfer and equilibrium model which treated the reaction of CO/sub 2/ with MDEA as second order and reversible, rather than pseudo-first order. The resulting activation energy was 13.7 kcal/gmol, and the rate constant at 30.5/sup 0/C was 4.0 (Ms)/sup -1/. The assumption of pseudo-first order conditions was found to reduce the apparent activationmore » energy to approximately 9 kcal/gmol. CO/sub 2/ absorption into 1.36 molal MDEA/0.61 molal MEA was studied at 31/sup 0/C. The experimental data were predicted better by a mass transfer model based on a shuttle mechanism than by one with two parallel reactions.« less

Center-Within-Trial Versus Trial-Level Evaluation of Surrogate Endpoints

PubMed Central

Renfro, Lindsay A.; Shi, Qian; Xue, Yuan; Li, Junlong; Shang, Hongwei; Sargent, Daniel J.

2014-01-01

Evaluation of candidate surrogate endpoints using individual patient data from multiple clinical trials is considered the gold standard approach to validate surrogates at both patient and trial levels. However, this approach assumes the availability of patient-level data from a relatively large collection of similar trials, which may not be possible to achieve for a given disease application. One common solution to the problem of too few similar trials involves performing trial-level surrogacy analyses on trial sub-units (e.g., centers within trials), thereby artificially increasing the trial-level sample size for feasibility of the multi-trial analysis. To date, the practical impact of treating trial sub-units (centers) identically to trials in multi-trial surrogacy analyses remains unexplored, and conditions under which this ad hoc solution may in fact be reasonable have not been identified. We perform a simulation study to identify such conditions, and demonstrate practical implications using a multi-trial dataset of patients with early stage colon cancer. PMID:25061255

Homogeneous photocatalytic oxidation of UV filter para-aminobenzoic acid in aqueous solutions.

PubMed

Tsoumachidou, Sophia; Lambropoulou, Dimitra; Poulios, Ioannis

2017-01-01

The presence of personal care product (PCP) residues in the aquatic environment is an emerging issue due to their uncontrolled release through graywater; for this reason, efforts are being made to develop methods to inactivate or eliminate this class of substances in the environment. In this work, homogeneous photocatalysis has been applied for the degradation of UV filter para-aminobenzoic acid (PABA), which exists in several types of PCPs, in order to identify the optimum degradation conditions. The oxidation of PABA by photo-Fenton and oxalate-induced photo-Fenton (ferrioxalate) processes was investigated, and the effect of various operating variables has been assessed, i.e., Fe 3+ (0.0035-0.014 g L -1 ), H 2 O 2 (0.025-0.2 g L -1 ), T (280-323 K), and type of radiation (UV-A, visible). Furthermore, experiments under optimal conditions have been performed in order to evaluate the transformation pathways and phytotoxicity of the treated PABA solution.

Stresses in adhesively bonded joints - A closed-form solution

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.; Aydinoglu, M. N.

1981-01-01

The general plane strain problem of adhesively bonded structures consisting of two different, orthotropic adherends is considered, under the assumption that adherend thicknesses are constant and small in relation to the lateral dimensions of the bonded region, so that they may be treated as plates. The problem is reduced to a system of differential equations for the adhesive stresses which is solved in closed form, with a single lap joint and a stiffened plate under various loading conditions being considered as examples. It is found that the plate theory used in the analysis not only predicts the correct trend for adhesive stresses but gives surprisingly accurate results, the solution being obtained by assuming linear stress-strain relations for the adhesive.

Development of a Nonequilibrium Radiative Heating Prediction Method for Coupled Flowfield Solutions

NASA Technical Reports Server (NTRS)

Hartung, Lin C.

1991-01-01

A method for predicting radiative heating and coupling effects in nonequilibrium flow-fields has been developed. The method resolves atomic lines with a minimum number of spectral points, and treats molecular radiation using the smeared band approximation. To further minimize computational time, the calculation is performed on an optimized spectrum, which is computed for each flow condition to enhance spectral resolution. Additional time savings are obtained by performing the radiation calculation on a subgrid optimally selected for accuracy. Representative results from the new method are compared to previous work to demonstrate that the speedup does not cause a loss of accuracy and is sufficient to make coupled solutions practical. The method is found to be a useful tool for studies of nonequilibrium flows.

Corrosion Analysis of TiCN Coated Al-7075 Alloy for Marine Applications: A Case Study

NASA Astrophysics Data System (ADS)

Srinath, M. K.; Ganesha Prasad, M. S.

2018-05-01

Corrosion is one of the most important marine difficulties that cause long term problems, occurring in ships and submarines surrounded by a corrosive environment when coupled with chemical, temperature and stress related conditions. Corrosion of marine parts could lead to severe disasters. Coatings and heat treatment in a very effective way could be used to protect the aluminium parts against corrosion. The present case study focuses on the corrosion and microstructural properties of TiCN coatings fabricated on Al-7075 aluminium alloy substrate by using Physical Vapour Deposition technique. Corrosion properties of specimen's heat treated at 500 °C at durations of 1, 4, 8 and 12 h were tested through salt spray test. According to D-1193, ASTM standard, corrosion resistance of coated and heat treated Al-7075 samples were investigated in solution kept at 95 °F with a pH of 6.5-7.2, with 5 sections of NaCl to 95 sections of type IV water. The specimen's heat treated for 1 h showed positive corrosion resistance, while the specimens treated for longer durations had the opposite effect. The microstructures of the salt spray tested coatings were investigated by scanning electron microscope. X-ray diffraction tests were conducted on specimens to determine the atomic and molecular structure of the surface crystals and the unit cell dimensions. The corrosion mechanisms of the coated specimens under the heat treated conditions have been explored.

Airplane dopes and doping

NASA Technical Reports Server (NTRS)

Smith, W H

1919-01-01

Cellulose acetate and cellulose nitrate are the important constituents of airplane dopes in use at the present time, but planes were treated with other materials in the experimental stages of flying. The above compounds belong to the class of colloids and are of value because they produce a shrinking action on the fabric when drying out of solution, rendering it drum tight. Other colloids possessing the same property have been proposed and tried. In the first stages of the development of dope, however, shrinkage was not considered. The fabric was treated merely to render it waterproof. The first airplanes constructed were covered with cotton fabric stretched as tightly as possible over the winds, fuselage, etc., and flying was possible only in fine weather. The necessity of an airplane which would fly under all weather conditions at once became apparent. Then followed experiments with rubberized fabrics, fabrics treated with glue rendered insoluble by formaldehyde or bichromate, fabrics treated with drying and nondrying oils, shellac, casein, etc. It was found that fabrics treated as above lost their tension in damp weather, and the oil from the motor penetrated the proofing material and weakened the fabric. For the most part the film of material lacked durability. Cellulose nitrate lacquers, however were found to be more satisfactory under varying weather conditions, added less weight to the planes, and were easily applied. On the other hand, they were highly inflammable, and oil from the motor penetrated the film of cellulose nitrate, causing the tension of the fabric to be relaxed.

Friction Freeform Fabrication of Superalloy Inconel 718: Prospects and Problems

NASA Astrophysics Data System (ADS)

Dilip, J. J. S.; Janaki Ram, G. D.

2014-01-01

Friction Freeform Fabrication is a new solid-state additive manufacturing process. The present investigation reports a detailed study on the prospects of this process for additive part fabrication in superalloy Inconel 718. Using a rotary friction welding machine and employing alloy 718 consumable rods in solution treated condition, cylindrical-shaped multi-layer friction deposits (10 mm diameter) were successfully produced. In the as-deposited condition, the deposits showed very fine grain size with no grain boundary δ phase. The deposits responded well to direct aging and showed satisfactory room-temperature tensile properties. However, their stress rupture performance was unsatisfactory because of their layered microstructure with very fine grain size and no grain boundary δ phase. The problem was overcome by heat treating the deposits first at 1353 K (1080 °C) (for increasing the grain size) and then at 1223 K (950 °C) (for precipitating the δ phase). Overall, the current study shows that Friction Freeform Fabrication is a very useful process for additive part fabrication in alloy 718.

Computational procedures for mixed equations with shock waves

NASA Technical Reports Server (NTRS)

Yu, N. J.; Seebass, R.

1974-01-01

This paper discusses the procedures we have developed to treat a canonical problem involving a mixed nonlinear equation with boundary data that imply a discontinuous solution. This equation arises in various physical contexts and is basic to the description of the nonlinear acoustic behavior of a shock wave near a caustic. The numerical scheme developed is of second order, treats discontinuities as such by applying the appropriate jump conditions across them, and eliminates the numerical dissipation and dispersion associated with large gradients. Our results are compared with the results of a first-order scheme and with those of a second-order scheme we have developed. The algorithm used here can easily be generalized to more complicated problems, including transonic flows with imbedded shocks.

PROCESS OF RECOVERING URANIUM

DOEpatents

Carter, J.M.; Larson, C.E.

1958-10-01

A process is presented for recovering uranium values from calutron deposits. The process consists in treating such deposits to produce an oxidlzed acidic solution containing uranium together with the following imparities: Cu, Fe, Cr, Ni, Mn, Zn. The uranium is recovered from such an impurity-bearing solution by adjusting the pH of the solution to the range 1.5 to 3.0 and then treating the solution with hydrogen peroxide. This results in the precipitation of uranium peroxide which is substantially free of the metal impurities in the solution. The peroxide precipitate is then separated from the solution, washed, and calcined to produce uranium trioxide.

Up-scaling mineral-aqueous interfacial processes that govern isotope and trace element partitioning during calcite growth

NASA Astrophysics Data System (ADS)

Lammers, L. N.

2014-12-01

The dependence of the isotopic and trace element composition of calcium carbonate minerals on growth conditions including temperature, pH, and salinity is widely used to infer paleoclimate conditions. These inferences rely heavily on phenomenological observations of biogenic and inorganic precipitation both in and ex situ, where only limited variability in solution conditions can be explored. Ionic fluxes between the mineral surface and aqueous growth solution govern the net uptake of both stoichiometric and trace species during calcification, so developing a mechanistic understanding of the reactions governing these fluxes is critical to refine existing proxies and to develop new ones. The micro-scale mechanisms of calcite precipitation from aqueous solution have been extensively studied, and net ionic uptake post-nucleation is known to occur primarily at monomolecular kink sites along step edges at the mineral surface. In this talk, I will present a theoretical framework that uses the quasi-elementary ion attachment and detachment reactions governing ion uptake at kink sites to simultaneously model bulk mineral growth kinetics and tracer partitioning during calcite precipitation. Several distinct processes occur during ion uptake at kink sites that can influence the distribution of trace species, directly impacting the composition of various carbonate paleoproxies including δ44Ca, δ18O, Sr/Ca and Mg/Ca. The distribution of these trace species will be shown to depend on (1) the relative rates of ion desolvation during attachment to kink sites, (2) the relative rates of bond breaking during detachment from kink sites, and (3) the equilibrium partitioning of trace aqueous species. This model accounts for the impact of solution conditions on net ion fluxes and surface speciation, which in turn controls the population of kink sites available for direct ion exchange with the aqueous phase. The impacts of solution variables including pH, temperature and salinity can be treated independently, which unlike traditional partitioning studies allows the impacts of these parameters to be deconvolved. The type of theoretical framework discussed here can be readily extended to explicitly account for each of the major solution composition variables that are implicated in paleoproxy composition.

Degree and duration of corneal anesthesia after topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution in ophthalmically normal dogs.

PubMed

Douet, Jean-Yves; Michel, Julien; Regnier, Alain

2013-10-01

To assess the anesthetic efficacy and local tolerance of topically applied 0.4% oxybuprocaine ophthalmic solution to in dogs and compare its effects with those of 1% tetracaine solution. 34 ophthalmically normal Beagles. Dogs were assigned to 2 groups, and baseline corneal touch threshold (CTT) was measured bilaterally with a Cochet-Bonnet aesthesiometer. Dogs of group 1 (n = 22) received a single drop of 0.4% oxybuprocaine ophthalmic solution in one eye and saline (0.9% NaCl) solution (control treatment) in the contralateral eye. Dogs of group 2 (n = 12) received a single drop of 0.4% oxybuprocaine ophthalmic solution in one eye and 1% tetracaine ophthalmic solution in the contralateral eye. The CTT of each eye was measured 1 and 5 minutes after topical application and then at 5-minute intervals until 75 minutes after topical application. CTT changes over time differed significantly between oxybuprocaine-treated and control eyes. After instillation of oxybuprocaine, maximal corneal anesthesia (CTT = 0) was achieved within 1 minute, and CTT was significantly decreased from 1 to 45 minutes, compared with the baseline value. No significant difference in onset, depth, and duration of corneal anesthesia was found between oxybuprocaine-treated and tetracaine-treated eyes. Conjunctival hyperemia and chemosis were detected more frequently in tetracaine-treated eyes than in oxybuprocaine-treated eyes. Topical application of oxybuprocaine and tetracaine similarly reduced corneal sensitivity in dogs, but oxybuprocaine was less irritating to the conjunctiva than was tetracaine.

METHOD OF SEPARATION

DOEpatents

Boyd, G.E.

1958-08-26

A process is presented fer separating uranium, plutonium, and fission products ions from uranyl nitrate solutions having a pH value between 1 and 3 obtained by dissolving neutron irradiated uranium. The method consists in passing such solutions through a bed of cation exchange resin, which may be a sulfonated phenol formaidehyde type. Following the adsorption step the resin is first treated with a solution of 0.2M to 0.3M sulfuric acid to desorb the uranium. Fission product ions are then desorbed by treating the resin in phosphoric acid and 1M in nitric acid. Lastly, the plutonium may be desorbed by treating the resin with a solution approximately 0.8M in phosphoric acid and 1M in nitric acid.

Treatment for primary hypothyroidism: current approaches and future possibilities

PubMed Central

Chakera, Ali J; Pearce, Simon HS; Vaidya, Bijay

2012-01-01

Primary hypothyroidism is the most common endocrine disease. Although the diagnosis and treatment of hypothyroidism is often considered simple, there are large numbers of people with this condition who are suboptimally treated. Even in those people with hypothyroidism who are biochemically euthyroid on levothyroxine replacement there is a significant proportion who report poorer quality of life. This review explores the historical and current treatment options for hypothyroidism, reasons for and potential solutions to suboptimal treatment, and future possibilities in the treatment of hypothyroidism. PMID:22291465

Cold worked ferritic alloys and components

DOEpatents

Korenko, Michael K.

1984-01-01

This invention relates to liquid metal fast breeder reactor and steam generator precipitation hardening fully ferritic alloy components which have a microstructure substantially free of the primary precipitation hardening phase while having cells or arrays of dislocations of varying population densities. It also relates to the process by which these components are produced, which entails solution treating the alloy followed by a final cold working step. In this condition, the first significant precipitation hardening of the component occurs during high temperature use.

Lectures on the Numerical Solution of Partial Differential Equations.

DTIC Science & Technology

1981-12-01

2 can be treated similarly. By a translation and a rotation, we can transform it to the do- main 2 : -45 ° ( 9 225 ° . It is a good exercise to ...of boundary conditions along the lateral surface does not naturally give rise to a two-dimensional plate model. I According to the Rivlin-Erzcksen...series (3.17). In the sequel, we shall be concerned with the computation of the first term (u,o) which, according to the above considerations, should

Air Force Operational Medicine: Using the Enterprise Estimating Supplies Program to Develop Materiel Solutions for the Operational Requirements of the Air Force Ophthalmology Augmentation Team (FFEYE)

DTIC Science & Technology

2010-10-14

non-battle injuries , and illnesses. International Classification of Diseases, Ninth Revision (ICD-9) coded patient conditions, selected by the...for a range of surgical and non- surgical injuries and illnesses, typically seen and treated by an ophthalmologist and one technician working 12-hour...receive them. The “Equipment/supplies” column identifies the items needed to complete the “Insert endo - trach tube” task at that level of capability. Not

Methods for removing contaminants from algal oil

DOEpatents

Lupton, Francis Stephen

2016-09-27

Methods for removing contaminants from algal oil are provided. In an embodiment, a method comprises the steps of combining a sulfuric acid-aqueous solution that has a pH of about 1 or less with a contaminant-containing algal oil at treatment conditions effective to form an effluent. The effluent comprises a treated algal oil phase and contaminants in an acidic aqueous phase. The contaminants comprise metals, phosphorus, or combinations thereof. The acidic aqueous phase is removed from the effluent to form a contaminant-depleted algal oil.

A computer program to evaluate optical systems

NASA Technical Reports Server (NTRS)

Innes, D.

1972-01-01

A computer program is used to evaluate a 25.4 cm X-ray telescope at a field angle of 20 minutes of arc by geometrical analysis. The object is regarded as a point source of electromagnetic radiation, and the optical surfaces are treated as boundary conditions in the solution of the electromagnetic wave propagation equation. The electric field distribution is then determined in the region of the image and the intensity distribution inferred. A comparison of wave analysis results and photographs taken through the telescope shows excellent agreement.

Habitability design elements for a space station

NASA Technical Reports Server (NTRS)

Dalton, M. C.

1983-01-01

Habitability in space refers to the components, characteristics, conditions, and design parameters that go beyond but include the basic life sustaining requirements. Elements of habitability covered include internal environment, architecture, mobility and restraint, food, clothing, personal hygiene, housekeeping, communications, and crew activities. All elements are interrelated and need to be treated as an overall discipline. Designing for a space station is similar to designing on earth but with 'space rules' instead of ground rules. It is concluded that some habitability problems require behavioral science solutions.

Novel Pharmacological Approaches for Treatment of Neurotoxicity Induced by Chronic Exposure to Depleted Uranium

DTIC Science & Technology

2010-09-01

control group and low (300 mg load) and high dose (600 mg load) DU exposure conditions, but utilized a vehicle and three drug-treated groups ( memantine ...applied long after exposure was initiated. The minipumps were filled with drug solutions of 30 mg/ml memantine (3.6 mg/kg/day dose) and/or 10 mg/ml...riluzole (1.2 mg/kg/day dose). Besides its potential usefulness as an uncompetitive NMDA receptor antagonist, memantine also has been reported to have

Novel Pharmacological Approaches for Treatment of Neurotoxicity Induced by Chronic Exposure to Depleted Uranium

DTIC Science & Technology

2008-09-01

treated groups ( memantine or riluzole or a combination) for each exposure level. This design results in a 3 exposure level × 4 drug condition...concentration is greater during this period than prior to 6 months exposure. The minipumps are filled with drug solutions of 30 mg/ml memantine (3.6 mg/kg/day...and/or 10 mg/ml riluzole (1.2 mg/kg/day). Besides its potential usefulness as an uncompetitive NMDA receptor antagonist, memantine also has been

Novel Pharmacological Approaches for Treatment of Neurotoxicity Induced by Chronic Exposure to Depleted Uranium

DTIC Science & Technology

2011-03-01

600 mg load) DU exposure conditions, but also utilized a vehicle and three drug-treated groups ( memantine or riluzole or a combination) for each...exposure was initiated. The minipumps were filled with drug solutions of 30 mg/ml memantine (3.6 mg/kg/day dose) and/or 10 mg/ml riluzole (1.2 mg/kg...day dose). Besides its potential usefulness as an uncompetitive NMDA receptor antagonist, memantine also has been reported to have neuroprotectant

Bicarbonate is not the ultimate answer to the biocompatibility problems of CAPD solutions: a cytotoxicity test of CAPD solutions and effluents.

PubMed

Schambye, H T; Pedersen, F B; Wang, P

1992-01-01

Human polymorphonuclear granulocytes (PMN) were tested for migration and phagocytosis after exposure to CAPD solutions and effluents sampled during the first hour of dialysis from patients treated with lactate or bicarbonate based CAPD-solutions. The effluents from the lactate based solutions (Dianeal and Lockolys) reduced the migration and enhanced the phagocytosis compared to values obtained in a standard cell culture medium. Both cell functions increased during the dialysis period. In contrast, the cell-function only changed slightly when 87b, a bicarbonate based CAPD-solution (pH = 7.4, [HCO3-) = 29mM), was employed. During the first 30 minutes, the cells performed at a higher level when exposed to the 87b effluent than when exposed to the lactate effluents. The observations further indicated that optimal conditions for PMNs are at a bicarbonate concentration of less than 20 mM and a lactate concentration of less than 15mM. PMN migration is reduced by both lactate and bicarbonate based CAPD solutions and effluents collected during the first hour of dialysis. The bio-compatibility of CAPD solutions may be improved by combining the lactate and bicarbonate buffering systems in a solution with a concentration of less than 20 mM of bicarbonate and less than 15 mM of lactate.

Feasibility of the UV/AA process as a pretreatment approach for bioremediation of dye-laden wastewater.

PubMed

Yang, Minghui; Wu, Bingdang; Li, Qiuhao; Xiong, Xiaofeng; Zhang, Haoran; Tian, Yu; Xie, Jiawen; Huang, Ping; Tan, Suo; Wang, Guodong; Zhang, Li; Zhang, Shujuan

2018-03-01

Biodegradability and toxicity are two important indexes in considering the feasibility of a chemical process for environmental remediation. The acetylacetone (AA) mediated photochemical process has been proven as an efficient approach for dye decolorization. Both AA and its photochemical degradation products had a high bioavailability. However, the biocompatibility and ecotoxicology of the UV/AA treated solutions are unclear yet. In the present work, we evaluated the biocompatibility and toxicity of the UV/AA treated solutions at both biochemical and organismal levels. The biodegradability of the treated solution was evaluated with the ratio of 5-d biological oxygen demand (BOD 5 ) to chemical oxygen demand (COD) and a 28-d activated sludge assay (Zahn-Wellens tests). The UV/AA process significantly improved the biodegradability of the tested dye solutions. Toxicity was assessed with responses of microorganisms (microbes in activated sludge and Daphnia magna) and plants (bok choy, rice seed, and Arabidopsis thaliana) to the treated solutions, which showed that the toxicity of the UV/AA treated solutions was lower or comparable to that of the UV/H 2 O 2 counterparts. The results are helpful for us to determine whether the UV/AA process is applicable to certain wastewaters and how the UV/AA process could be effectively combined into a sequential chemical-biological water treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Existence of frozen-in coordinate systems

NASA Technical Reports Server (NTRS)

Chertkov, A. D.

1995-01-01

The 'frozen-in' coordinate systems were first introduced in the works on 'reconnection' and 'magnetic barrier' theories (see review by M.l.Pudovkin and V.S.Semenov, Space Sci. Rev. 41,1 1985). The idea was to utilize the mathematical apparatus developed for 'general relativity' theory to simplify obtaining solutions to the ideal MHD equations set. Magnetic field (B), plasma velocity (v), and their vector product were used as coordinate vectors. But there exist no stationary solutions of ideal MHD set that satisfies the required boundary conditions at infinity (A.D.Chertkov, Solar Wind Seven Conf.,Pergamon Press,1992,165) having non-zero vector product of v and B where v and B originate from the same sphere. The existence of a solution is the hidden mine of the mentioned theories. The solution is constructed in the coordinate system, which is unknown and indeterminate before obtaining this solution. A substitution of the final solution must be done directly into the initial MHD set in order to check the method. One can demonstrate that 'solutions' of Petschek's problem, obtained by 'frozen-in' coordinate systems, does not satisfy just the 'frozen-in' equation, i.e. induction equation. It stems from the fact that Petschek's 're-connection' model, treated as a boundary problem, is over determined. This problem was incorrectly formulated.

Leachate Properties and Cadmium Migration Through Freeze-thaw Treated Soil Columns.

PubMed

Xu, Meng; Zheng, Yue; Chen, Weiwei; Mao, Na; Guo, Ping

2017-01-01

Soil column leaching experiments were conducted to study the effects of multiple freeze-thaw cycles on the vertical migration of cadmium (Cd). Three Cd-spiked leaching solutions of different properties were derived from snowmelt, sludge, and straw, designated as B, W and J, respectively. The leaching solutions varied in dissolved organic matter (DOM) concentrations in the order of J > W > B. Changes in leachate properties and Cd concentration were observed. The results showed that pH values of all the leachate solutions through freeze-thaw treated soil columns were higher than those of leachates through unfrozen soils. However, electrical conductivity (EC) values decreased compared with leachates in unfrozen treated soil columns. Although the concentrations of DOM in leachate solutions had no evident differences between the freeze-thaw and unfrozen treated soil columns, the concentrations of DOM in the leachate solutions B, W and J were different. Freeze-thaw cycles resulted in increased concentrations of Cd in the leachate solutions in the order J > W > B, and promoted a deeper migration of Cd in the soil columns. Thus, it was shown that freeze-thaw cycles may increase the risk of groundwater pollution by Cd.

System of treating flue gas

DOEpatents

Ziegler, D.L.

1975-12-01

A system is described for treating or cleaning incinerator flue gas containing acid gases and radioactive and fissionable contaminants. Flue gas and a quench solution are fed into a venturi and then tangentially into the lower portion of a receptacle for restricting volumetric content of the solution. The upper portion of the receptacle contains a scrub bed to further treat or clean the flue gas.

Effect of Galla chinensis on the remineralization of two bovine root lesions morphous in vitro.

PubMed

Guo, Bin; Que, Ke-Hua; Jing Yang; Wang, Bo; Liang, Qian-Qian; Xie, Hong-Hui

2012-09-01

The present study aims to evaluate the effect of Galla chinensis compounds on the remineralization of two artificial root lesions morphous in vitro. Sixty bovine dentine blocks were divided into two groups and individually treated with two levels of demineralization solutions to form erosive and subsurface artificial carious lesions in vitro. Each group was then divided into three subgroups, each of which were treated with a remineralization solution (positive control), deionized water (negative control), or 4 000 mg⋅L(-1) aqueous solutions of Galla chinensis extract. The dentine blocks were then subjected to a pH-cycling regime for 7 days. During the first 4 days, the daily cycle included 21-h deal and 3-h demineralization applications. The dentine blocks were dealt with the entire day during the remaining 3 days. Two specimens from each of the treatment groups were selected and observed under a polarized light microscope. Data collected using a laser scanning confocal microscope were computerized and analyzed. Galla chinensis extract clearly enhanced the remineralization of both erosive lesion and subsurface lesion patterns in the specimens (P<0.05). The level of remineralization of the erosive lesion by Galla chinensis extract was lower than that of the subsurface lesion (P<0.05). In addition, the remineralization of the subsurface lesion by Galla chinensis extract was higher than that of the remineralization solution (P<0.05). No significant difference between the remineralization of erosive lesions by Galla chinensis extract and the remineralization solution was observed (P>0.05). So Galla chinensis extract has the potential to improve the remineralization of artificial root lesions under dynamic pH-cyclic conditions, indicating its potential use as a natural remineralization medicine.

Characterization of friction and moisture of porcine lingual tissue in vitro in response to artificial saliva and mouthwash solutions.

PubMed

Zundel, J; Ansari, S A; Trivedi, H M; Masters, J G; Mascaro, S

2018-05-07

The purpose of this research is to characterize the effects of mouthwash solutions on oral friction and moisture using a quantitative in vitro approach. The frictional coefficient of in vitro porcine tongue samples was measured using a magnetic levitation haptic device equipped with a custom tactor designed to mimic human skin. A commercially available moisture meter was used to measure moisture content of the samples. Tongue samples were first tested before treatment, then after application of saliva (either human or artificial), and again after application of 1 of 11 different mouthwash solutions. The data indicate that the samples treated with artificial saliva vs real saliva have comparable friction coefficient and moisture content. Furthermore, the moisture and friction coefficient remain relatively constant for up to 60 minutes after exposure to ambient conditions. Samples treated with artificial saliva have an average friction coefficient in the range of 0.70-0.80. Application of mouthwash solutions produced an average friction coefficient of 0.39-0.49 but retained the high moisture content of the artificial salivary layer. Several mouthwash solutions resulted in statistically significant differences in the friction coefficient relative to each other. The results of this study demonstrate that a magnetic levitation device can be an effective tool for in vitro oral tribology and that artificial saliva is an effective substitute for real saliva in extended in vitro experiments. The application of mouthwash generally reduces the coefficient of friction of the tongue samples while preserving a relatively high moisture level, and some mouthwashes reduce friction significantly more than others. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Solubilities of carbon dioxide in aqueous potassium carbonate solutions mixed with physical solvents

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

Park, S.B.; Lee, H.; Lee, K.H.

1998-09-01

The removal of acidic gases such as CO{sub 2}, H{sub 2}S, and COS from gas streams is a very important operation for petrochemical, oil refineries, ammonia manufacture, coal gasification, and natural gas purification plants. Here, the solubilities of carbon dioxide in aqueous potassium carbonate (K{sub 2}CO{sub 3}) solutions mixed with physical solvents were measured at 298.2 and 323.2 K with a CO{sub 2} partial-pressure range of 5 kPa to 2 MPa. 1,2-propanediol and propylene carbonate were selected as physical solvents. The aqueous solutions treated in this study were 5 mass% K{sub 2}CO{sub 3}-15 mass% 1,2-propanediol and propylene carbonate were selectedmore » as physical solvents. The aqueous solutions treated in this study were 5 mass% K{sub 2}CO{sub 3}-15 mass% propylene carbonate. The experimental solubility results were presented by the mole ratio of CO{sub 2} and K{sub 2}CO{sub 3} contained in the liquid mixture. The addition of 1,2-propanediol to 5 mass% K{sub 2}CO{sub 3} solution lowered the solubility of CO{sub 2} at constant temperature and pressure conditions when CO{sub 2} partial-pressure range of 5 kPa to 2 MPa. In the case of propylene carbonate the addition of propylene carbonate increased the experimental solubilities in the region of low CO{sub 2} partial pressures and decreased as the CO{sub 2} partial pressure was increased above atmospheric. The solubilities of CO{sub 2} decreased with increasing temperature in the range of 298.2 to 323.2 K.« less

Toxicity of chlorine to zebrafish embryos

PubMed Central

Kent, Michael L.; Buchner, Cari; Barton, Carrie; Tanguay, Robert L.

2014-01-01

Surface disinfection of fertilized fish eggs is widely used in aquaculture to reduce extraovum pathogens that may be released from brood fish during spawning, and this is routinely used in zebrafish (Danio rerio) research laboratories. Most laboratories use approximately 25 – 50 ppm unbuffered chlorine solution for 5 – 10 min. Treatment of embryos with chlorine has significant germicidal effects for many Gram-negative bacteria, viruses, and trophozoite stages of protozoa, it has reduced efficacy against cyst or spore stages of protozoa and certain Mycobacterium spp. Therefore, we evaluated the toxicity of unbufferred and buffered chlorine solution to embryos exposed at 6 or 24 hours post-fertilization (hpf) to determine if higher concentrations can be used for treating zebrafish embryos. Most of our experiments entailed using an outbred line (5D), with both mortality and malformations as endpoints. We found that 6 hpf embryos consistently were more resistant than 24 hpf embryos to the toxic effects of chlorine. Chlorine is more toxic and germicidal at lower pHs, and chlorine causes elevated pH. Consistent with this, we found that unbufferred chlorine solutions (pH ca 8–9) were less toxic at corresponding concentrations than solutions buffered to pH 7. Based on our findings here, we recommend treating 6 hpf embryos for 10 min and 24 hpf for 5 min with unbuffered chlorine solution at 100 ppm. One trial indicated that AB fish, a popular outbred line, are more susceptible to toxicity than 5Ds. This suggests that variability between zebrafish lines occurs, and researchers should evaluate each line or strain under their particular laboratory conditions for selection of the optimum chlorine treatment procedure. PMID:24429474

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.

Peracetic acid oxidation of saline waters in the absence and presence of H ₂O ₂: secondary oxidant and disinfection byproduct formation.

PubMed

Shah, Amisha D; Liu, Zheng-Qian; Salhi, Elisabeth; Höfer, Thomas; von Gunten, Urs

2015-02-03

Peracetic acid (PAA) is a disinfectant considered for use in ballast water treatment, but its chemical behavior in such systems (i.e., saline waters) is largely unknown. In this study, the reactivity of PAA with halide ions (chloride and bromide) to form secondary oxidants (HOCl, HOBr) was investigated. For the PAA-chloride and PAA-bromide reactions, second-order rate constants of (1.47 ± 0.58) × 10(-5) and 0.24 ± 0.02 M(-1) s(-1) were determined for the formation of HOCl or HOBr, respectively. Hydrogen peroxide (H2O2), which is always present in PAA solutions, reduced HOCl or HOBr to chloride or bromide, respectively. As a consequence, in PAA-treated solutions with [H2O2] > [PAA], the HOBr (HOCl) steady-state concentrations were low with a limited formation of brominated (chlorinated) disinfection byproducts (DBPs). HOI (formed from the PAA-iodide reaction) affected this process because it can react with H2O2 back to iodide. H2O2 is thus consumed in a catalytic cycle and leads to less efficient HOBr scavenging at even low iodide concentrations (<1 μM). In PAA-treated solutions with [H2O2] < [PAA] and high bromide levels, mostly brominated DBPs are formed. In synthetic water, bromate was formed from the oxidation of bromide. In natural brackish waters, bromoform (CHBr3), bromoacetic acid (MBAA), dibromoacetic acid (DBAA), and tribromoacetic acid (TBAA) formed at up to 260, 106, 230, and 89 μg/L, respectively for doses of 2 mM (ca. 150 mg/L) PAA and [H2O2] < [PAA]. The same brackish waters, treated with PAA with [H2O2] ≫ [PAA], similar to conditions found in commercial PAA solutions, resulted in no trihalomethanes and only low haloacetic acid concentrations.

Feasibility study for epidemic prevention and control in a regional hospital.

PubMed

Chen, Yung-Liang; Yeh, Ming-Yang; Huang, Shau-Yen; Liu, Chi-Ming; Sun, Chi-Chen; Lu, Hsu-Feng; Chiu, Tsan-Hung; Hsia, Te-Chun; Chung, Jing-Gung

2012-03-01

Epidemic prevention policies in hospitals address issues such as, indoor air quality control, cleanliness of medical staff clothing and employee hand-washing procedures. Our hospital employed Bio-Kil to treat air-conditioning filters and nursing staff uniforms. We also assessed the efficacy of different detergents. Using Bio-Kil technology, the mean bacterial count in the air was reduced from 108.8 CFU/h/plate (n=420) to 68.6 CFU/h/plate (n=630). On the lower hems of the Bio-Kil-treated gowns, the mean bacterial count was 1,201 CFU/100 cm(2), markedly lower than the bacterial count of 7,753 CFU/100 cm(2), found on the parts of the gowns not treated with Bio-Kil (p=0.0401). On the cuffs of sleeves treated with Bio-Kil, the mean count was 1,165 CFU/100 cm(2), markedly lower than that of 2,131 CFU/100 cm(2), found on the cuffs not treated with Bio-Kil (p=0.0073). With regard to the mean bacterial eradication rates of antimicrobial solutions, Steridal Solution, 75% alcohol and Bio-Kil (3rd generation) were shown to be the most effective, with rates exceeding 80%. Hibiscrub with paper towels and Fresh Protect Skin were the second most effective. Bio-Kil (1st generation), tap water with paper towels, liquid hand soap with paper towels and ozone water were the least effective. One important observation was that hand-washing without the use of paper towels increased the bacterial count by as much as 84% . Bio-Kil is effective in reducing bacterial counts in the air, on nursing staff uniforms and is an effective detergent.

General chemical kinetics computer program for static and flow reactions, with application to combustion and shock-tube kinetics

NASA Technical Reports Server (NTRS)

Bittker, D. A.; Scullin, V. J.

1972-01-01

A general chemical kinetics program is described for complex, homogeneous ideal-gas reactions in any chemical system. Its main features are flexibility and convenience in treating many different reaction conditions. The program solves numerically the differential equations describing complex reaction in either a static system or one-dimensional inviscid flow. Applications include ignition and combustion, shock wave reactions, and general reactions in a flowing or static system. An implicit numerical solution method is used which works efficiently for the extreme conditions of a very slow or a very fast reaction. The theory is described, and the computer program and users' manual are included.

Spectral methods in time for a class of parabolic partial differential equations

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

Ierley, G.; Spencer, B.; Worthing, R.

1992-09-01

In this paper, we introduce a fully spectral solution for the partial differential equation u[sub t] + uu[sub x] + vu[sub xx] + [mu]u[sub xxx] + [lambda]u[sub xxxx] = O. For periodic boundary conditions in space, the use of a Fourier expansion in x admits of a particularly efficient algorithm with respect to expansion of the time dependence in a Chebyshev series. Boundary conditions other than periodic may still be treated with reasonable, though lesser, efficiency. for all cases, very high accuracy is attainable at moderate computational cost relative to the expense of variable order finite difference methods in time.more » 14 refs., 9 figs.« less

Transcranial route of brain targeted delivery of methadone in oil.

PubMed

Pathirana, W; Abhayawardhana, P; Kariyawasam, H; Ratnasooriya, W D

2009-05-01

The unique anatomical arrangement of blood vessels and sinuses in the human skull and the brain, the prevalence of a high density of skin appendages in the scalp, extracranial vessels of the scalp communicating with the brain via emissary veins and most importantly, the way that the scalp is used in Ayurvedic medical system in treating diseases associated with the brain show that a drug could be transcranially delivered and targeted to the brain through the scalp. The present study was to investigate by measuring the antinociceptive effect on rats whether the opioid analgesic methadone could be delivered and targeted to the brain by transcranial delivery route. A non aqueous solution of methadone base in sesame oil was used for the application on the scalp. Animal studies were carried out using six groups of male rats consisting of group 1, the oral control treated with distilled water 1 ml; group 2, the oral positive control treated with methadone hydrochloride solution 316.5 mug/ml; group 3, the negative control treated transcranially with the blank sesame oil 0.2 ml and three test groups 4, 5 and 6 treated with three different dose levels of the transcranial oil formulation of methadone base, 41.6 mug/0.2 ml, 104 mug/0.2 ml and 208 mug/0.2 ml, respectively. The antinociceptive effects were examined by subjecting the rats to the hot plate and tail flick tests. The two higher concentrations of the three transcranial methadone formulations yielded response vs time curves showing nearly equal maximum antinociceptive effects similar to that of the oral positive control. Maximum analgesic effect after transcranial administration was observed between 1st and 2nd h and declined up to 6th hour. The results indicate that the transcranial brain targeted delivery of methadone base in the form of an oil based non aqueous solution results in statistically significant antinociceptive effects under experimental conditions. Therefore, it is possible to deliver central nervous system drugs through the proposed transcranial route when suitably formulated.

Removal of residual contaminants in petroleum-contaminated soil by Fenton-like oxidation.

PubMed

Lu, Mang; Zhang, Zhongzhi; Qiao, Wei; Guan, Yueming; Xiao, Meng; Peng, Chong

2010-07-15

The degradation of bioremediation residues by hydrogen peroxide in petroleum-contaminated soil was investigated at circumneutral pH using a Fenton-like reagent (ferric ion chelated with EDTA). Batch tests were done on 20 g soil suspended in 60 mL aqueous solution containing hydrogen peroxide and Fe(3+)-EDTA complex under constant stirring. A slurry reactor was used to treat the soil based on the optimal reactant conditions. Contaminants were characterized by Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the optimal treatment condition was: the molar ratio of hydrogen peroxide to iron=200:1, and pH 7.0. Under the optimum condition, total dichloromethane-extractable organics were reduced from 14,800 to 2300 mg kg(-1) soil when the accumulative H(2)O(2) dosage was 2.45 mol kg(-1) soil during the reactor treatment. Abundance of viable cells was lower in incubated Fenton-like treated soil than in untreated soil. Oxidation of contaminants produced remarkable compositional and structural modifications. A fused ring compound, identified as C(34)H(38)N(1), was found to exhibit the greatest resistance to oxidation. 2010 Elsevier B.V. All rights reserved.

Improving the treatment of non-aqueous phase TCE in low permeability zones with permanganate.

PubMed

Chokejaroenrat, Chanat; Comfort, Steve; Sakulthaew, Chainarong; Dvorak, Bruce

2014-03-15

Treating dense non-aqueous phase liquids (DNAPLs) embedded in low permeability zones (LPZs) is a particularly challenging issue for injection-based remedial treatments. Our objective was to improve the sweeping efficiency of permanganate (MnO4(-)) into LPZs to treat high concentrations of TCE. This was accomplished by conducting transport experiments that quantified the penetration of various permanganate flooding solutions into a LPZ that was spiked with non-aqueous phase (14)C-TCE. The treatments we evaluated included permanganate paired with: (i) a shear-thinning polymer (xanthan); (ii) stabilization aids that minimized MnO2 rind formation and (iii) a phase-transfer catalyst. In addition, we quantified the ability of these flooding solutions to improve TCE destruction under batch conditions by developing miniature LPZ cylinders that were spiked with (14)C-TCE. Transport experiments showed that MnO4(-) alone was inefficient in penetrating the LPZ and reacting with non-aqueous phase TCE, due to a distinct and large MnO2 rind that inhibited the TCE from further oxidant contact. By including xanthan with MnO4(-), the sweeping efficiency increased (90%) but rind formation was still evident. By including the stabilization aid, sodium hexametaphosphate (SHMP) with xanthan, permanganate penetrated 100% of the LPZ, no rind was observed, and the percentage of TCE oxidized increased. Batch experiments using LPZ cylinders allowed longer contact times between the flooding solutions and the DNAPL and results showed that SHMP+MnO4(-) improved TCE destruction by ∼16% over MnO4(-) alone (56.5% vs. 40.1%). These results support combining permanganate with SHMP or SHMP and xanthan as a means of treating high concentrations of TCE in low permeable zones. Copyright © 2014 Elsevier B.V. All rights reserved.

The influence of aluminum and carbon on the abrasion resistance of high manganese steels

NASA Astrophysics Data System (ADS)

Buckholz, Samuel August

Abrasive wear testing of lightweight, austenitic Fe-Mn-Al-C cast steel has been performed in accordance with ASTM G65 using a dry sand, rubber wheel, abrasion testing apparatus. Testing was conducted on a series of Fe-30Mn-XAl-YC-1Si-0.5Mo chemistries containing aluminum levels from 2.9 to 9.5 wt.% and carbon levels from 0.9 to 1.83 wt.%. Solution treated materials having an austenitic microstructure produced the highest wear resistance. Wear resistance decreased with higher aluminum, lower carbon, and higher hardness after age hardening. In the solution treated condition the wear rate was a strong function of the aluminum to carbon ratio and the wear rate increased with a parabolic dependence on the Al/C ratio, which ranged from 1.8 to 10.2. Examination of the surface wear scar revealed a mechanism of plowing during abrasion testing and this method of material removal is sensitive to work hardening rate. Work hardening behavior was determined from tensile tests and also decreased with increasing Al/C ratio and after aging hardening. The loss of wear resistance is related to short range ordering of Al and C in the solution treated materials and kappa-carbide precipitation in age hardened materials and both contribute to planar slip and lower work hardening rates. A high carbon tool steel (W1) and a bainitic low alloy steel (SAE 8620) were also tested for comparison. A lightweight steel containing 6.5 wt.% Al and 1.2 wt.% C has wear resistance comparable to within 5% of the bainitic SAE 8620 steel forging currently used for the Bradley Fighting Vehicle track shoe and this cast Fe-Mn-Al-C steel, at equivalent tensile properties, would be 10% lighter.

URANIUM RECOVERY PROCESS

DOEpatents

Bailes, R.H.; Long, R.S.; Olson, R.S.; Kerlinger, H.O.

1959-02-10

A method is described for recovering uranium values from uranium bearing phosphate solutions such as are encountered in the manufacture of phosphate fertilizers. The solution is first treated with a reducing agent to obtain all the uranium in the tetravalent state. Following this reduction, the solution is treated to co-precipitate the rcduced uranium as a fluoride, together with other insoluble fluorides, thereby accomplishing a substantially complete recovery of even trace amounts of uranium from the phosphate solution. This precipitate usually takes the form of a complex fluoride precipitate, and after appropriate pre-treatment, the uranium fluorides are leached from this precipitate and rccovered from the leach solution.

Influence of processing parameters on the characteristics of surface layers of low temperature plasma nitrocarburized AISI 630 martensitic stainless steel

NASA Astrophysics Data System (ADS)

Lee, Insup

2017-11-01

Plasma nitrocarburizing was performed on solution-treated AISI 630 martensitic precipitation hardening stainless steel samples with a gas mixture of H2, N2, and CH4 with changing temperature, discharge voltage and amount of CH4. When nitrocarburized with increasing temperature from 380 °C to 430 °C at fixed 25% N2 and 6% CH4, the thickness of expanded martensite (α'N) layer and surface hardness increased up to 10 μm and 1323 HV0.05, respectively but the corrosion resistance decreased. Though the increase of discharge voltage from 400 V to 600 V increased α'N layer thickness and surface hardness (up to 13 μm and 1491 HV0.05, respectively), the treated samples still showed very poor corrosion behavior. Thus, to further improve the corrosion resistance, the influence of variation of the amount of CH4 in the nitrocarburizing process was investigated. Increasing the CH4 percentage aided higher corrosion resistance, although it decreased the α'N layer thickness. The most appropriate conditions for moderate α'N layer thickness, high surface hardness and better corrosion resistance than the solution-treated bare sample were established, which is plasma nitrocarburizing at 400 °C with 400 V discharge voltage and containing 25% N2 and 4% CH4.

The effect of different parameters on the development of compressive strength of oil palm shell geopolymer concrete.

PubMed

Kupaei, Ramin Hosseini; Alengaram, U Johnson; Jumaat, Mohd Zamin

2014-01-01

This paper presents the experimental results of an on-going research project on geopolymer lightweight concrete using two locally available waste materials--low calcium fly ash (FA) and oil palm shell (OPS)--as the binder and lightweight coarse aggregate, respectively. OPS was pretreated with three different alkaline solutions of sodium hydroxide (NaOH), potassium hydroxide, and sodium silicate as well as polyvinyl alcohol (PVA) for 30 days; afterwards, oil palm shell geopolymer lightweight concrete (OPSGPC) was cast by using both pretreated and untreated OPSs. The effect of these solutions on the water absorption of OPS, and the development of compressive strength in different curing conditions of OPSGPC produced by pretreated OPS were investigated; subsequently the influence of NaOH concentration, alkaline solution to FA ratio (A/FA), and different curing regimes on the compressive strength and density of OPSGPC produced by untreated OPS was inspected. The 24-hour water absorption value for OPS pretreated with 20% and 50% PVA solution was about 4% compared to 23% for untreated OPS. OPSGPC produced from OPS treated with 50% PVA solution produced the highest compressive strength of about 30 MPa in ambient cured condition. The pretreatment with alkaline solution did not have a significant positive effect on the water absorption of OPS aggregate and the compressive strength of OPSGPC. The result revealed that a maximum compressive strength of 32 MPa could be obtained at a temperature of 65°C and curing period of 4 days. This investigation also found that an A/FA ratio of 0.45 has the optimum amount of alkaline liquid and it resulted in the highest level of compressive strength.

The Effect of Different Parameters on the Development of Compressive Strength of Oil Palm Shell Geopolymer Concrete

PubMed Central

Kupaei, Ramin Hosseini; Alengaram, U. Johnson; Jumaat, Mohd Zamin

2014-01-01

This paper presents the experimental results of an on-going research project on geopolymer lightweight concrete using two locally available waste materials—low calcium fly ash (FA) and oil palm shell (OPS)—as the binder and lightweight coarse aggregate, respectively. OPS was pretreated with three different alkaline solutions of sodium hydroxide (NaOH), potassium hydroxide, and sodium silicate as well as polyvinyl alcohol (PVA) for 30 days; afterwards, oil palm shell geopolymer lightweight concrete (OPSGPC) was cast by using both pretreated and untreated OPSs. The effect of these solutions on the water absorption of OPS, and the development of compressive strength in different curing conditions of OPSGPC produced by pretreated OPS were investigated; subsequently the influence of NaOH concentration, alkaline solution to FA ratio (A/FA), and different curing regimes on the compressive strength and density of OPSGPC produced by untreated OPS was inspected. The 24-hour water absorption value for OPS pretreated with 20% and 50% PVA solution was about 4% compared to 23% for untreated OPS. OPSGPC produced from OPS treated with 50% PVA solution produced the highest compressive strength of about 30 MPa in ambient cured condition. The pretreatment with alkaline solution did not have a significant positive effect on the water absorption of OPS aggregate and the compressive strength of OPSGPC. The result revealed that a maximum compressive strength of 32 MPa could be obtained at a temperature of 65°C and curing period of 4 days. This investigation also found that an A/FA ratio of 0.45 has the optimum amount of alkaline liquid and it resulted in the highest level of compressive strength. PMID:25531006

Development and validation spectroscopic methods for the determination of lomefloxacin in bulk and pharmaceutical formulations

NASA Astrophysics Data System (ADS)

El-Didamony, A. M.; Hafeez, S. M.

2016-01-01

Four simple, sensitive spectrophotometric and spectrofluorimetric methods (A-D) for the determination of antibacterial drug lomefloxacin (LMFX) in pharmaceutical formulations have been developed. Method A is based on formation of ternary complex between Pd(II), eosin and LMFX in the presence of methyl cellulose as surfactant and acetate-HCl buffer pH 4.0. Spectrophotometrically, under the optimum conditions, the ternary complex showed absorption maximum at 530 nm. Methods B and C are based on redox reaction between LMFX and KMnO4 in acid and alkaline media. In indirect spectrophotometry method B the drug solution is treated with a known excess of KMnO4 in H2SO4 medium and subsequent determination of unreacted oxidant by reacting it with safronine O in the same medium at λmax = 520 nm. Direct spectrophotometry method C involves treating the alkaline solution of LMFX with KMnO4 and measuring the bluish green product at 604 nm. Method D is based on the chelation of LMFX with Zr(IV) to produce fluorescent chelate. At the optimum reaction conditions, the drug-metal chelate showed excitation maxima at 280 nm and emission maxima at 443 nm. The optimum experimental parameters for the reactions have been studied. The validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods were successfully applied for the determination of the selected drug in pharmaceutical preparations with good recoveries.

Diffusing wave spectroscopy studies of gelling systems

NASA Astrophysics Data System (ADS)

Horne, David S.

1991-06-01

The recognition that the transmission of light through a concentrated, opaque system can be treated as a diffusion process has extended the application of photon correlation techniques to the study of particle size, mobility and interactions in such systems. Solutions of the photon diffusion equation are sensitive to the boundary conditions imposed by the geometry of the scattering apparatus. The apparatus, incorporating a bifurcated fiber optic bundle for light transmission between source, sample and detector, takes advantage of the particularly simple solution for a back-scattering configuration. Its ability to measure particle size using monodisperse polystyrene latices and to respond to concentration dependent particle interactions in a study of casein micelle mobility in skim and concentrated milks is demonstrated. Finally, the changes in dynamic light scattering behavior occurring during colloidal gel formation are described and discussed.

Stainless and Galvanized Steel, Hydrophobic Admixture and Flexible Polymer-Cement Coating Compared in Increasing Durability of Reinforced Concrete Structures

NASA Astrophysics Data System (ADS)

Tittarelli, Francesca; Giosuè, Chiara; Mobili, Alessandra

2017-08-01

The use of stainless or galvanized steel reinforcements, a hydrophobic admixture or a flexible polymer-cement coating were compared as methods to improve the corrosion resistance of sound or cracked reinforced concrete specimens exposed to chloride rich solutions. The results show that in full immersion condition, negligible corrosion rates were detected in all cracked specimens, except those treated with the flexible polymer-cement mortar as preventive method against corrosion and the hydrophobic concrete specimens. High corrosion rates were measured in all cracked specimens exposed to wet-dry cycles, except for those reinforced with stainless steel, those treated with the flexible polymer-cement coating as restorative method against reinforcement corrosion and for hydrophobic concrete specimens reinforced with galvanized steel reinforcements.

[The effect of nitrates on the outcome of acute experimental ischemic stroke].

PubMed

Kuzenkov, V S; Krushinskiĭ, A L; Reutov, V P

2012-01-01

Effects of nitrates NaNO(3), KNO(3), Mg(NO(3)) 2 on animals (Wistar rats) were studied on the basis of the experimental model of ischemic stroke induced by the occlusion of two carotid arteries. The animals were divided into two groups: the main group (n=60) and the control group (n=30). Three series of experiments were conducted. In each experiment, the rats of the main group were treated with one of nitrates and the control group was treated with physiological solution. It has been shown that nitrates exert either positive or negative effect depending on the cation type, nitrate concentration and the duration of their action on the dynamics of neurologic disturbances. Conditions of the development of neuroprotective effect of nitrates are discussed.

An approximate analytical solution for describing surface runoff and sediment transport over hillslope

NASA Astrophysics Data System (ADS)

Tao, Wanghai; Wang, Quanjiu; Lin, Henry

2018-03-01

Soil and water loss from farmland causes land degradation and water pollution, thus continued efforts are needed to establish mathematical model for quantitative analysis of relevant processes and mechanisms. In this study, an approximate analytical solution has been developed for overland flow model and sediment transport model, offering a simple and effective means to predict overland flow and erosion under natural rainfall conditions. In the overland flow model, the flow regime was considered to be transitional with the value of parameter β (in the kinematic wave model) approximately two. The change rate of unit discharge with distance was assumed to be constant and equal to the runoff rate at the outlet of the plane. The excess rainfall was considered to be constant under uniform rainfall conditions. The overland flow model developed can be further applied to natural rainfall conditions by treating excess rainfall intensity as constant over a small time interval. For the sediment model, the recommended values of the runoff erosion calibration constant (cr) and the splash erosion calibration constant (cf) have been given in this study so that it is easier to use the model. These recommended values are 0.15 and 0.12, respectively. Comparisons with observed results were carried out to validate the proposed analytical solution. The results showed that the approximate analytical solution developed in this paper closely matches the observed data, thus providing an alternative method of predicting runoff generation and sediment yield, and offering a more convenient method of analyzing the quantitative relationships between variables. Furthermore, the model developed in this study can be used as a theoretical basis for developing runoff and erosion control methods.

Effect of irrigation with treated wastewater on soil chemical properties and infiltration rate.

PubMed

Bedbabis, Saida; Ben Rouina, Béchir; Boukhris, Makki; Ferrara, Giuseppe

2014-01-15

In Tunisia, water scarcity is one of the major constraints for agricultural activities. The reuse of treated wastewater (TWW) in agriculture can be a sustainable solution to face water scarcity. The research was conducted for a period of four years in an olive orchard planted on a sandy soil and subjected to irrigation treatments: a) rain-fed conditions (RF), as control b) well water (WW) and c) treated wastewater (TWW). In WW and TWW treatments, an annual amount of 5000 m(3) ha(-1) of water was supplied to the orchard. Soil samples were collected at the beginning of the study and after four years for each treatment. The main soil properties such as electrical conductivity (EC), pH, soluble cations, chloride (Cl(-)), sodium adsorption ratio (SAR), organic matter (OM) as well as the infiltration rate were investigated. After four years, either a significant decrease of pH and infiltration rate or a significant increase of OM, SAR and EC were observed in the soil subjected to treated wastewater treatment. Copyright © 2013. Published by Elsevier Ltd.

Technetium and Iodine Getters to Improve Cast Stone Performance

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

Qafoku, Nikolla; Neeway, James J.; Lawter, Amanda R.

2014-07-01

To determine the effectiveness of the various getter materials prior to their solidification in Cast Stone, a series of batch sorption experiments was performed at Pacific Northwest National Laboratory. To quantify the effectiveness of the removal of Tc(VII) and I(I) from solution by getters, the distribution coefficient, Kd (mL/g), was calculated. Testing involved placing getter material in contact with spiked waste solutions at a 1:100 solid-to-solution ratio for periods up to 45 days with periodic solution sampling. One Tc getter was also tested at a 1:10 solid-to-solution ratio. Two different solution media, 18.2 MΩ deionized water (DI H2O) and amore » 7.8 M Na LAW simulant, were used in the batch sorption tests. Each test was conducted at room temperature in an anoxic chamber containing N2 with a small amount of H2 (0.7%) to maintain anoxic conditions. Each getter-solution combination was run in duplicate. Three Tc- and I-doping concentrations were used separately in aliquots of both the 18.2 MΩ DI H2O and a 7.8 M Na LAW waste simulant. The 1× concentration was developed based on Hanford Tank Waste Operations Simulator (HTWOS) model runs to support the River Protection Project System Plan Revision 6. The other two concentrations were 5× and 10× of the HTWOS values. The Tc and I tests were run separately (i.e., the solutions did not contain both solutes). Sampling of the solid-solution mixtures occurred nominally after 0.2, 1, 3, 6, 9, 12, 15 days and ~35 to 45 days. Seven getter materials were tested for Tc and five materials were tested for I. The seven Tc getters were blast furnace slag 1 (BFS1) (northwest source), BFS2 (southeast source), Sn(II)-treated apatite, Sn(II) chloride, nano tin phosphate, KMS (a potassium-metal-sulfide), and tin hydroxapatite. The five iodine getters were layered bismuth hydroxide (LBH), argentite mineral, synthetic argentite, silver-treated carbon, and silver-treated zeolite. The Tc Kd values measured from experiments conducted using the 7.8 M Na LAW simulant (the simulant selected to represent LAW) for the first 15 days for four Tc getters (BFS1, BFS2, Sn(II)-treated apatite, and Sn(II) chloride) show no, to a very small, capacity to remove Tc from the LAW simulant. For the Tc-getter experiments in the 7.8 M LAW simulant, the majority of the effluent samples show very small drops in Tc concentrations for the 35-day compared to the 15-day samplings. However, the Tc concentration in the simulant blanks also dropped slightly during this period, so the effect of the getter contacting LAW simulant at 35 days compared to 15 days is minimal; except that the BFS1 1:10 test shows a slow but steady decrease in Tc concentration in the LAW simulant supernatant from the beginning to the 35 day contact at which point about 20% of the original Tc has been removed from solution. Lastly, the KMS getter gives the highest Kd value for Tc at 35 days where Kd values have increased to 104 mL/g. When considering the different I getters reacting with the 7.8 M LAW simulant, two getters are much more effective than the others: Ag zeolite and Syn Arg. The other getters have calculated iodide distribution coefficients that show very limited effectiveness in the caustic conditions created by the LAW simulant. These are preliminary results that will need more detailed analyses including both pre- and post-batch sorption getter solid-phase characterization using state-of-the-art instrumentation such as synchrotron X ray absorption spectroscopy, which can delineate the oxidation state of the Tc and likely iodine species as well as some of the getters key major components, sulfur and iron in the BFS, and tin and sulfur in the tin-bearing and sulfur-bearing getters. This report also describes future experimental studies to be performed to better elucidate the mechanisms controlling the Tc and I sequestration processes in the various getters and leach tests of getter-bearing Cast Stone monoliths.« less

Technetium and Iodine Getters to Improve Cast Stone Performance

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

Qafoku, Nikolla; Neeway, James J.; Lawter, Amanda R.

2015-02-19

To determine the effectiveness of the various getter materials prior to their solidification in Cast Stone, a series of batch sorption experiments was performed at Pacific Northwest National Laboratory. To quantify the effectiveness of the removal of Tc(VII) and I(I) from solution by getters, the distribution coefficient, K d (mL/g), was calculated. Testing involved placing getter material in contact with spiked waste solutions at a 1:100 solid-to-solution ratio for periods up to 45 days with periodic solution sampling. One Tc getter was also tested at a 1:10 solid-to-solution ratio. Two different solution media, 18.2 MΩ deionized water (DI H 2O)more » and a 7.8 M Na LAW simulant, were used in the batch sorption tests. Each test was conducted at room temperature in an anoxic chamber containing N2 with a small amount of H 2 (0.7%) to maintain anoxic conditions. Each getter-solution combination was run in duplicate. Three Tc- and I-doping concentrations were used separately in aliquots of both the 18.2 MΩ DI H2O and a 7.8 M Na LAW waste simulant. The 1× concentration was developed based on Hanford Tank Waste Operations Simulator (HTWOS) model runs to support the River Protection Project System Plan Revision 6. The other two concentrations were 5× and 10× of the HTWOS values. The Tc and I tests were run separately (i.e., the solutions did not contain both solutes). Sampling of the solid-solution mixtures occurred nominally after 0.2, 1, 3, 6, 9, 12, 15 days and ~35 to 45 days. Seven getter materials were tested for Tc and five materials were tested for I. The seven Tc getters were blast furnace slag 1 (BFS1) (northwest source), BFS2 (southeast source), Sn(II)-treated apatite, Sn(II) chloride, nano tin phosphate, KMS (a potassium-metal-sulfide), and tin hydroxapatite. The five iodine getters were layered bismuth hydroxide (LBH), argentite mineral, synthetic argentite, silver-treated carbon, and silver-treated zeolite. The Tc Kd values measured from experiments conducted using the 7.8 M Na LAW simulant (the simulant selected to represent LAW) for the first 15 days for four Tc getters (BFS1, BFS2, Sn(II)-treated apatite, and Sn(II) chloride) show no, to a very small, capacity to remove Tc from the LAW simulant. For the Tc-getter experiments in the 7.8 M LAW simulant, the majority of the effluent samples show very small drops in Tc concentrations for the 35-day compared to the 15-day samplings. However, the Tc concentration in the simulant blanks also dropped slightly during this period, so the effect of the getter contacting LAW simulant at 35 days compared to 15 days is minimal; except that the BFS1 1:10 test shows a slow but steady decrease in Tc concentration in the LAW simulant supernatant from the beginning to the 35 day contact at which point about 20% of the original Tc has been removed from solution. Lastly, the KMS getter gives the highest K d value for Tc at 35 days where K d values have increased to 104 mL/g. When considering the different I getters reacting with the 7.8 M LAW simulant, two getters are much more effective than the others: Ag zeolite and Syn Arg. The other getters have calculated iodide distribution coefficients that show very limited effectiveness in the caustic conditions created by the LAW simulant. These are preliminary results that will need more detailed analyses including both pre- and post-batch sorption getter solid-phase characterization using state-of-the-art instrumentation such as synchrotron X-ray absorption spectroscopy, which can delineate the oxidation state of the Tc and likely iodine species as well as some of the getters key major components, sulfur and iron in the BFS, and tin and sulfur in the tin-bearing and sulfur-bearing getters. This report also describes future experimental studies to be performed to better elucidate the mechanisms controlling the Tc and I sequestration processes in the various getters and leach tests of getter-bearing Cast Stone monoliths.« less

Comparative Studies on Microstructure, Mechanical and Pitting Corrosion of Post Weld Heat Treated IN718 Superalloy GTA and EB Welds

NASA Astrophysics Data System (ADS)

Dilkush; Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

2018-03-01

In the present study, an attempt has been made to weld Inconel 718 nickel-base superalloy (IN718 alloy) using gas tungsten arc welding (GTAW) and electron beam welding (EBW) processes. Both the weldments were subjected to post-weld heat treatment condition as follows -980°C / 20 min followed by direct aging condition (DA) as 720°C/8 h/FC followed by 620°C/8 h/AC. The GTA and EB welds of IN718 alloy were compared in two conditions as-received and 980STA conditions. Welds were characterized to observe mechanical properties, pitting corrosion resistance by correlating with observed microstructures. The rate of higher cooling ranges, the fusion zone of EBW exhibited discrete and relative finer lave phases whereas the higher niobium existed laves with coarser structure were observed in GTAW. The significant dissolution of laves were observed at 980STA of EBW. Due to these effects, the EBW of IN718 alloy showed the higher mechanical properties than GTAW. The electrochemical potentiostatic etch test was carried out in 3.5wt% sodium chloride (NaCl) solution to study the pitting corrosion behaviour of the welds. Results of the present investigation established that mechanical properties and pitting corrosion behaviour are significantly better in post weld heat treated condition. The comparative studies showed that the better combination of mechanical properties and pitting corrosion resistance were obtained in 980STA condition of EBW than GTAW.

Proteus two-dimensional Navier-Stokes computer code, version 2.0. Volume 1: Analysis description

NASA Technical Reports Server (NTRS)

Towne, Charles E.; Schwab, John R.; Bui, Trong T.

1993-01-01

A computer code called Proteus 2D was developed to solve the two-dimensional planar or axisymmetric, Reynolds-averaged, unsteady compressible Navier-Stokes equations in strong conservation law form. The objective in this effort was to develop a code for aerospace propulsion applications that is easy to use and easy to modify. Code readability, modularity, and documentation were emphasized. The governing equations are solved in generalized nonorthogonal body-fitted coordinates, by marching in time using a fully-coupled ADI solution procedure. The boundary conditions are treated implicitly. All terms, including the diffusion terms, are linearized using second-order Taylor series expansions. Turbulence is modeled using either an algebraic or two-equation eddy viscosity model. The thin-layer or Euler equations may also be solved. The energy equation may be eliminated by the assumption of constant total enthalpy. Explicit and implicit artificial viscosity may be used. Several time step options are available for convergence acceleration. The documentation is divided into three volumes. This is the Analysis Description, and presents the equations and solution procedure. The governing equations, the turbulence model, the linearization of the equations and boundary conditions, the time and space differencing formulas, the ADI solution procedure, and the artificial viscosity models are described in detail.

Proteus three-dimensional Navier-Stokes computer code, version 1.0. Volume 1: Analysis description

NASA Technical Reports Server (NTRS)

Towne, Charles E.; Schwab, John R.; Bui, Trong T.

1993-01-01

A computer code called Proteus 3D has been developed to solve the three dimensional, Reynolds averaged, unsteady compressible Navier-Stokes equations in strong conservation law form. The objective in this effort has been to develop a code for aerospace propulsion applications that is easy to use and easy to modify. Code readability, modularity, and documentation have been emphasized. The governing equations are solved in generalized non-orthogonal body-fitted coordinates by marching in time using a fully-coupled ADI solution procedure. The boundary conditions are treated implicitly. All terms, including the diffusion terms, are linearized using second-order Taylor series expansions. Turbulence is modeled using either an algebraic or two-equation eddy viscosity model. The thin-layer or Euler equations may also be solved. The energy equation may be eliminated by the assumption of constant total enthalpy. Explicit and implicit artificial viscosity may be used. Several time step options are available for convergence acceleration. The documentation is divided into three volumes. This is the Analysis Description, and presents the equations and solution procedure. It describes in detail the governing equations, the turbulence model, the linearization of the equations and boundary conditions, the time and space differencing formulas, the ADI solution procedure, and the artificial viscosity models.

Application of Sawdust modified with m-DMDHEU/Choline chloride for the removal of CrO4 2- and H2AsO4 - in water

NASA Astrophysics Data System (ADS)

Dang, N. T.; Quan, P. T.; Sang, P. H. P.

2017-06-01

This article studies the use of acacia auriculiformis wood sawdust modified with 4,5-dihydroxy-1,3-bis (methoxymethyl) imidazolidin-2-one (m-DMDHEU) and choline chloride for separating CrO4 2- and H2AsO4 - ions in water. NaOH 0.2N/ethanol 70° solution was used to remove lignin from the raw material, the material was then immersed in m-DMDHEU/choline chloride aqueous solution for 24 hours, after that the material was activated at 140oC for one hour. The ability to adsorb and exchange ions of the material was examined using solutions containing CrO4 2- and H2AsO4 - ions in different conditions. The results suggested that the ability to separate CrO4 2- and H2AsO4 - ions of the modified material was better than that of anion resin at pH = 7.0; the chromate adsorption capacity was the highest in acidic condition; the presence of arsenate (V) anions had no effect on the ability to remove chromate. Lastly, the modified material was used to treat water samples containing concentrations of arsenic similar to groundwater in several arsenic-contaminated areas of Vietnam.

Treatment of greywater by forward osmosis technology: role of the operating temperature.

PubMed

Wang, Ce; Li, Yongmei; Wang, Yanqiang

2018-06-04

Effects of operating conditions were investigated in terms of water flux, reverse salt flux (RSF) and pollutant rejection in a forward osmosis (FO) membrane system treating synthetic greywater. Changing cross-flow velocity had a slight impact on the performance of the FO membrane. Elevating operating temperature was more effective than increasing draw solution concentration to enhance the water flux. Further observation on the effect of heating mode showed that when the temperature was increased from 20 to 30°C, heating the feed solution (FS) side was better than heating the draw solution (DS) side or heating both sides; further increasing the temperature to 40 and 50°C, heating both the FS and DS achieved much higher water flux compared with only increasing the FS or DS temperature. Under isothermal conditions, a higher water flux and a lower RSF were achieved at 40°C than at other temperatures. Changing either FS or DS temperature had similar influences on water flux and RSF. The FO process revealed high rejection of nitrate (95.7%-100%), ammonia nitrogen (98.8%-100%), total nitrogen (97.4%-99.9%), linear alkylbenzene sulfonate (100%) and Mg (97.5%-100%). A mathematical model that could well simulate the water flux evolution in the present FO system was recommended.

Adsorption of Cu(II) from aqueous solution on sulfuric acid treated palygorskite

NASA Astrophysics Data System (ADS)

Niu, Yan-Ning; Yuan, Yuan; Gao, Wei-Xin; Qian, Sheng; Sun, Wen

2018-03-01

The absorption behavior of Cu2+ from aqueous solution on sulfuric acid treated palygorskite were investigated, the results showed that palygorskite had high absorption ability for Cu2+ from aqueous solution. Effects of the shaking time, pH and the copper ion concentration on the removal rate were discussed. The absorption behavior of Cu2+ could be well imitated by the Langmuir isothermal equation.

Laboratory and Field Evaluation of the Entomopathogenic Fungus Beauveria bassiana (Deuteromycotina: Hyphomycetes) for Population Management of Spruce Beetle, Dendroctonus rufipennis (Coleoptera: Scolytinae), in Felled Trees and Factors Limiting Pathogen Success.

PubMed

Davis, Thomas Seth; Mann, Andrew J; Malesky, Danielle; Jankowski, Egan; Bradley, Clifford

2018-03-24

An isolate of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. (Deuteromycotina: Hyphomycetes) was tested for its ability to reduce survival and reproduction of spruce beetle, Dendroctonus rufipennis (Kirby) (Coleoptera: Scolytinae), under laboratory and field conditions. Conidial suspension applied directly to adults or to filter papers that adults contacted had a median survival time of 3-4 d in laboratory assays and beetles died more rapidly when exposed to conidial suspension than when treated with surfactant solution only. In the field, conidial suspension was applied to the surface of felled and pheromone-baited Engelmann spruce (Picea engelmannii) trees using a backpack sprayer. Mortality of colonizing parent beetles (F0), reproduction (abundance of F1 offspring in logs), and emergence of F1 beetles from logs was compared between treated and nontreated logs. Application of spore suspension increased mortality of F0 adults by 36% on average. Total F1 reproduction was reduced by 17% and emergence from logs was reduced by 13% in treated logs, but considerable variability in reproduction and emergence was observed. Viable spores were re-isolated from treated logs up to 90 d after application, indicating that spores are capable of long-term persistence on the tree bole microhabitat. Subsequent in vitro tests revealed that temperatures below 15°C and exposure to spruce monoterpenes likely limit performance of B. bassiana under field conditions, but exposure to low-intensity light or interactions with spruce beetle symbiotic fungi were not strongly inhibitory. It is concluded that matching environmental tolerances of biocontrol fungi to field conditions can likely improve their usefulness for control of spruce beetle in windthrown trees.

METHOD OF SEPARATING PLUTONIUM FROM LANTHANUM FLUORIDE CARRIER

DOEpatents

Watt, G.W.; Goeckermann, R.H.

1958-06-10

An improvement in oxidation-reduction type methods of separating plutoniunn from elements associated with it in a neutron-irradiated uranium solution is described. The method relates to the separating of plutonium from lanthanum ions in an aqueous 0.5 to 2.5 N nitric acid solution by 'treating the solution, at room temperature, with ammonium sulfite in an amount sufficient to reduce the hexavalent plutonium present to a lower valence state, and then treating the solution with H/sub 2/O/sub 2/ thereby forming a tetravalent plutonium peroxide precipitate.

Ultimate boundedness stability and controllability of hereditary systems

NASA Technical Reports Server (NTRS)

Chukwu, E. N.

1979-01-01

By generalizing the Liapunov-Yoshizawa techniques, necessary and sufficient conditions are given for uniform boundedness and uniform ultimate boundedness of a rather general class of nonlinear differential equations of neutral type. Among the applications treated by the methods are the Lienard equation of neutral type and hereditary systems of Lurie type. The absolute stability of this later equation is also investigated. A certain existence result of a solution of a neutral functional differential inclusion with two point boundary values is applied to study the exact function space controllability of a nonlinear neutral functional differential control system. A geometric growth condition is used to characterize both the function space and Euclidean controllability of another nonlinear delay system which has a compact and convex control set. This yields conditions under which perturbed nonlinear delay controllable systems are controllable.

Studies on urine treatment by biological purification using Azolla and UV photocatalytic oxidation

NASA Astrophysics Data System (ADS)

Liu, Xiaofeng; Chen, Min; Bian, Zuliang; Liu, Chung-Chu

The amount of water consumed in space station operations is very large. In order to reduce the amount of water which must be resupplied from Earth, the space station needs to resolve the problems of water supply. For this reason, the recovery, regeneration and utilization of urine of astronauts are of key importance. Many investigations on this subject have been reported. Our research is based on biological absorption and, purification using UV photocatalytic oxidation techniques to achieve comprehensive treatment for urine. In the treatment apparatus we created, the urine solution is used as part of the nutrient solution for the biological components in our bioregenerative life support system. After being absorbed, the nutrients from the urine were then decomposed, metabolized and purified which creates a favorable condition for the follow-up oxidation treatment by UV photocatalytic oxidation. After these two processes, the treated urine solution reached Chinese national standards for drinking water quality (GB5749-1985).

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

DOEpatents

Vijayan, S.; Wong, C.F.; Buckley, L.P.

1994-11-22

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved. 1 fig.

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

DOEpatents

Vijayan, Sivaraman; Wong, Chi F.; Buckley, Leo P.

1994-01-01

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved.

Fast Proton Titration Scheme for Multiscale Modeling of Protein Solutions.

PubMed

Teixeira, Andre Azevedo Reis; Lund, Mikael; da Silva, Fernando Luís Barroso

2010-10-12

Proton exchange between titratable amino acid residues and the surrounding solution gives rise to exciting electric processes in proteins. We present a proton titration scheme for studying acid-base equilibria in Metropolis Monte Carlo simulations where salt is treated at the Debye-Hückel level. The method, rooted in the Kirkwood model of impenetrable spheres, is applied on the three milk proteins α-lactalbumin, β-lactoglobulin, and lactoferrin, for which we investigate the net-charge, molecular dipole moment, and charge capacitance. Over a wide range of pH and salt conditions, excellent agreement is found with more elaborate simulations where salt is explicitly included. The implicit salt scheme is orders of magnitude faster than the explicit analog and allows for transparent interpretation of physical mechanisms. It is shown how the method can be expanded to multiscale modeling of aqueous salt solutions of many biomolecules with nonstatic charge distributions. Important examples are protein-protein aggregation, protein-polyelectrolyte complexation, and protein-membrane association.

The combined use of NPWT and instillation using an octenidine based wound rinsing solution: a case study.

PubMed

Matiasek, J; Djedovic, G; Mattesich, M; Morandi, E; Pauzenberger, R; Pikula, R; Verstappen, R; Pierer, G; Koller, R; Rieger, U M

2014-11-01

Effective wound bed preparation is an essential element in the healing of chronic wounds, including pressure ulcers (PUs). Negative pressure wound therapy (NPWT) reduces oedema, stimulates the formation of granulation tissue and helps remove wound exudate. This helps prepare the wound bed for secondary healing, skin grafting or coverage with flaps. Combining NPWT with an instillation phase using an antiseptic (octenidine based) irrigation solution is a novel approach to PU management. Three patients with Category 4 gluteal PUs were treated with NPWT and instillation fluid, following surgical debridement of necrotic tissue. The aim was to achieve optimal wound bed preparation prior to wound closure by local fasciocutaneous flap. The antiseptic efficacy of octenilin wound irrigation solution in microorganism eradication was quantified by in vitro tests simulating real conditions using leg ulcer vacuum exudates. All wounds completely healed after four weeks, and no adverse incidents occurred due to instillation of octenidine. No recurrence of the PU occurred during a one year follow-up.

Compositions and methods for treating nuclear fuel

DOEpatents

Soderquist, Chuck Z; Johnsen, Amanda M; McNamara, Bruce K; Hanson, Brady D; Smith, Steven C; Peper, Shane M

2013-08-13

Compositions are provided that include nuclear fuel. Methods for treating nuclear fuel are provided which can include exposing the fuel to a carbonate-peroxide solution. Methods can also include exposing the fuel to an ammonium solution. Methods for acquiring molybdenum from a uranium comprising material are provided.

Compositions and methods for treating nuclear fuel

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

Soderquist, Chuck Z; Johnsen, Amanda M; McNamara, Bruce K

Compositions are provided that include nuclear fuel. Methods for treating nuclear fuel are provided which can include exposing the fuel to a carbonate-peroxide solution. Methods can also include exposing the fuel to an ammonium solution. Methods for acquiring molybdenum from a uranium comprising material are provided.

Reduction of Salmonella on chicken breast fillets stored under aerobic or modified atmosphere packaging by the application of lytic bacteriophage preparation SalmoFreshTM.

PubMed

Sukumaran, Anuraj T; Nannapaneni, Rama; Kiess, Aaron; Sharma, Chander Shekhar

2016-03-01

The present study evaluated the efficacy of recently approved Salmonella lytic bacteriophage preparation (SalmoFresh™) in reducing Salmonella on chicken breast fillets, as a surface and dip application. The effectiveness of phage in combination with modified atmosphere packaging (MAP) and the ability of phage preparation in reducing Salmonella on chicken breast fillets at room temperature was also evaluated. Chicken breast fillets inoculated with a cocktail of Salmonella Typhimurium, S. Heidelberg, and S. Enteritidis were treated with bacteriophage (10(9) PFU/mL) as either a dip or surface treatment. The dip-treated samples were stored at 4°C aerobically and the surface-treated samples were stored under aerobic and MAP conditions (95% CO2/5% O2) at 4°C for 7 d. Immersion of Salmonella-inoculated chicken breast fillets in bacteriophage solution reduced Salmonella (P < 0.05) by 0.7 and 0.9 log CFU/g on d 0 and d 1 of storage, respectively. Surface treatment with phage significantly (P < 0.05) reduced Salmonella by 0.8, 0.8, and 1 log CFU/g on d 0, 1, and 7 of storage, respectively, under aerobic conditions. Higher reductions in Salmonella counts were achieved on chicken breast fillets when the samples were surface treated with phage and stored under MAP conditions. The Salmonella counts were reduced by 1.2, 1.1, and 1.2 log CFU/g on d 0, 1, and 7 of storage, respectively. Bacteriophage surface application on chicken breast fillets stored at room temperature reduced the Salmonella counts by 0.8, 0.9, and 0.4 log CFU/g after 0, 4, and 8 h, respectively, compared to the untreated positive control. These findings indicate that lytic phage preparation was effective in reducing Salmonella on chicken breast fillets stored under aerobic and modified atmosphere conditions. © 2015 Poultry Science Association Inc.

The antimicrobial effect of benzalkonium chloride on some pathogenic microbes observed on fibers of acrylic carpet.

PubMed

Khajavi, Ramin; Sattari, Morteza; Ashjaran, Ali

2007-02-15

In the presented research, the main aim is to investigate the antibacterial effectiveness of BAC solutions on acrylic fibers used in machinery carpet. An acrylic pile carpet laid in a public place for 30 days and the existence of some microbes were investigated on it. The antimicrobial effect of different BAC solutions for identified microbes was studied in vitro. The acrylic fibers were treated with the same different solutions of BAC as before and the antibacterial effectiveness was assessed by the zone of inhibition method in different times. Two pieces of carpet untreated and treated with BAC solution sewed together and laid for one week in the public place and the amounts of bacterial growth determined by colony count method and the results compared. Finally some mechanical properties of treated acrylic fibers measured after 30 days and compared with untreated one. The results showed the presence of some pathogenic microbes on the laid carpet such as Escherichia coli and Staphylococcus aureus. The inhalation time for treated acrylic fibers improved. The amount of colony growth on treated carpet reduced considerably and besides the mechanical tests results showed no significant deterioration effect of studied properties in comparing with untreated yarn.

Physical approach to quantum networks with massive particles

NASA Astrophysics Data System (ADS)

Andersen, Molte Emil Strange; Zinner, Nikolaj Thomas

2018-04-01

Assembling large-scale quantum networks is a key goal of modern physics research with applications in quantum information and computation. Quantum wires and waveguides in which massive particles propagate in tailored confinement is one promising platform for realizing a quantum network. In the literature, such networks are often treated as quantum graphs, that is, the wave functions are taken to live on graphs of one-dimensional edges meeting in vertices. Hitherto, it has been unclear what boundary conditions on the vertices produce the physical states one finds in nature. This paper treats a quantum network from a physical approach, explicitly finds the physical eigenstates and compares them to the quantum-graph description. The basic building block of a quantum network is an X-shaped potential well made by crossing two quantum wires, and we consider a massive particle in such an X well. The system is analyzed using a variational method based on an expansion into modes with fast convergence and it provides a very clear intuition for the physics of the problem. The particle is found to have a ground state that is exponentially localized to the center of the X well, and the other symmetric solutions are formed so to be orthogonal to the ground state. This is in contrast to the predictions of the conventionally used so-called Kirchoff boundary conditions in quantum graph theory that predict a different sequence of symmetric solutions that cannot be physically realized. Numerical methods have previously been the only source of information on the ground-state wave function and our results provide a different perspective with strong analytical insights. The ground-state wave function has a spatial profile that looks very similar to the shape of a solitonic solution to a nonlinear Schrödinger equation, enabling an analytical prediction of the wave number. When combining multiple X wells into a network or grid, each site supports a solitonlike localized state. These localized solutions only couple to each other and are able to jump from one site to another as if they were trapped in a discrete lattice.

Enhanced photovoltaic properties in dye sensitized solar cells by surface treatment of SnO2 photoanodes

PubMed Central

Basu, Kaustubh; Benetti, Daniele; Zhao, Haiguang; Jin, Lei; Vetrone, Fiorenzo; Vomiero, Alberto; Rosei, Federico

2016-01-01

We report the fabrication and testing of dye sensitized solar cells (DSSC) based on tin oxide (SnO2) particles of average size ~20 nm. Fluorine-doped tin oxide (FTO) conducting glass substrates were treated with TiOx or TiCl4 precursor solutions to create a blocking layer before tape casting the SnO2 mesoporous anode. In addition, SnO2 photoelectrodes were treated with the same precursor solutions to deposit a TiO2 passivating layer covering the SnO2 particles. We found that the modification enhances the short circuit current, open-circuit voltage and fill factor, leading to nearly 2-fold increase in power conversion efficiency, from 1.48% without any treatment, to 2.85% achieved with TiCl4 treatment. The superior photovoltaic performance of the DSSCs assembled with modified photoanode is attributed to enhanced electron lifetime and suppression of electron recombination to the electrolyte, as confirmed by electrochemical impedance spectroscopy (EIS) carried out under dark condition. These results indicate that modification of the FTO and SnO2 anode by titania can play a major role in maximizing the photo conversion efficiency. PMID:26988622

Gradient Augmented Level Set Method for Two Phase Flow Simulations with Phase Change

NASA Astrophysics Data System (ADS)

Anumolu, C. R. Lakshman; Trujillo, Mario F.

2016-11-01

A sharp interface capturing approach is presented for two-phase flow simulations with phase change. The Gradient Augmented Levelset method is coupled with the two-phase momentum and energy equations to advect the liquid-gas interface and predict heat transfer with phase change. The Ghost Fluid Method (GFM) is adopted for velocity to discretize the advection and diffusion terms in the interfacial region. Furthermore, the GFM is employed to treat the discontinuity in the stress tensor, velocity, and temperature gradient yielding an accurate treatment in handling jump conditions. Thermal convection and diffusion terms are approximated by explicitly identifying the interface location, resulting in a sharp treatment for the energy solution. This sharp treatment is extended to estimate the interfacial mass transfer rate. At the computational cell, a d-cubic Hermite interpolating polynomial is employed to describe the interface location, which is locally fourth-order accurate. This extent of subgrid level description provides an accurate methodology for treating various interfacial processes with a high degree of sharpness. The ability to predict the interface and temperature evolutions accurately is illustrated by comparing numerical results with existing 1D to 3D analytical solutions.

Microstructural studies on failure mechanisms in thermo-mechanical fatigue of repaired DS R80 and IN 738 Superalloys

NASA Astrophysics Data System (ADS)

Abrokwah, Emmanuel Otchere

Directionally solidified Rene 80 (DS R80) and polycrystalline Inconel 738(IN 738) Superalloys were tested in thermo-mechanical fatigue (TMF) over the temperature range of 500-900°C and plastic strain range from 0.1 to 0.8% using a DSI Gleeble thermal simulator. Thermo-mechanical testing was carried out on the parent material (baseline) in the conventional solution treated and aged condition (STA), as well as gas tungsten arc welded (GTAW) with an IN-738 filler, followed by solution treatment and ageing. Comparison of the baseline alloy microstructure with that of the welded and heat treated alloy showed that varying crack initiation mechanisms, notably oxidation by stress assisted grain boundary oxidation, grain boundary MC carbides fatigue crack initiation, fatigue crack initiation from sample surfaces, crack initiation from weld defects and creep deformation were operating, leading to different “weakest link” and failure initiation points. The observations from this study show that the repaired samples had extra crack initiation sites not present in the baseline, which accounted for their occasional poor fatigue life. These defects include lack of fusion between the weld and the base metal, fusion zone cracking, and heat affected zone microfissures.

Citric acid modified kenaf core fibres for removal of methylene blue from aqueous solution.

PubMed

Sajab, Mohd Shaiful; Chia, Chin Hua; Zakaria, Sarani; Jani, Saad Mohd; Ayob, Mohd Khan; Chee, Kah Leong; Khiew, Poi Sim; Chiu, Wee Siong

2011-08-01

Chemically modified kenaf core fibres were prepared via esterification in the presence of citric acid (CA). The adsorption kinetics and isotherm studies were carried out under different conditions to examine the adsorption efficiency of CA-treated kenaf core fibres towards methylene blue (MB). The adsorption capacity of the kenaf core fibres increased significantly after the citric acid treatment. The values of the correlation coefficients indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich isotherm. The maximum adsorption capacity of the CA-treated kenaf core fibres was found to be 131.6mg/g at 60°C. Kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion, were employed to describe the adsorption mechanism. The kinetic data were found to fit pseudo-second-order model equation as compared to pseudo-first-order model. The adsorption of MB onto the CA-treated kenaf core fibres was spontaneous and endothermic. Copyright © 2011 Elsevier Ltd. All rights reserved.

Collinear swimmer propelling a cargo sphere at low Reynolds number.

PubMed

Felderhof, B U

2014-11-01

The swimming velocity and rate of dissipation of a linear chain consisting of two or three little spheres and a big sphere is studied on the basis of low Reynolds number hydrodynamics. The big sphere is treated as a passive cargo, driven by the tail of little spheres via hydrodynamic and direct elastic interaction. The fundamental solution of Stokes equations in the presence of a sphere with a no-slip boundary condition, as derived by Oseen, is used to model the hydrodynamic interactions between the big sphere and the little spheres.

Method for encapsulating nanoparticles in a zeolite matrix

DOEpatents

Coker, Eric N.

2007-12-11

A method for preparing a metal nanocluster composite material. A porous zeolitic material is treated with an aqueous metal compound solution to form a metal ion-exchanged zeolitic material, heated at a temperature ramp rate of less than 2.degree. C./min to an elevated temperature, cooled, contacted with an organic monomer and heating to induce polymerization, and heating the composite material to greater than 350.degree. C. under non-oxidizing conditions to form a metal nanocluster-carbon composite material with nanocluster sizes between approximately 0.6 nm and 10 nm.

Study on the protection of CDP-choline against nicotine intoxication.

PubMed

Grau, T; Romero, A; Sacristán, A; Ortiz, J A

1983-01-01

Cytidine diphosphate choline (CDP-choline, citicoline, Somazina) was orally administered to a group of mice at a dose of 1 g/kg for 4 days. Simultaneously, another group of mice were treated under similar conditions with 0.25% agar suspension. Then, animals were distributed into subgroups of 10 mice each and intravenous increasing doses of nicotine bitartrate were administered. By comparing the toxicity induced by nicotine in the animals receiving CDP-choline with that in animals receiving agar solution, a remarkable difference of the LD50 was observed between both groups.

Determining Optimal Microwave Antigen Retrieval Conditions for Microtubule-Associated Protein 2 Immunohistochemistry in the Guinea Pig Brain

DTIC Science & Technology

2002-12-01

sections of formalin-fixed guinea pig brains using different MAP-2 monoclonal antibodies. Brain sections were boiled in sodium citrate, citric acid...citric acid solution at pH 6.0 is the optimal microwave-assisted AR method for immunolabeling MAP-2 in formalin-fixed, paraffin-processed guinea pig brain...studies on archival guinea pig brain paraffin blocks, ultimately relaxing the use of additional animals to evaluate changes in MAP-2 expression between chemical warfare nerve agent-treated and control samples.

Carrier tests to assess the effective sporicidal concentration of a liquid chemical disinfectant for a sanitization program.

PubMed

Ceccanti, Stefano; Giampieri, Simona; Burgalassi, Susi

2011-01-01

The aim of the present investigation was to evaluate the microbial efficacy against highly resistant bacterial spores on different substrates using the lowest effective concentration of a market liquid sporicide based on peracetic acid. The validation was carried out following modified European regulatory agencies procedures or test methods and USP guidelines, employing carriers of materials usually treated with the sporicidal solution and present in grade A cleanrooms and spores of four different microorganisms: Bacillus subtilis and Clostridium sporogenes, both from the ATCC collection, and Bacillus cereus and Bacillus sphaericus as environmental isolates. A statistical evaluation of data was made to estimate the variance for different study conditions. The experiments highlighted that 70% suitable dilution of the ready-to-use peracetic acid solution was effective in both clean and dirty conditions, showing at least 2 log spore reduction after treatment. To obtain effective sporicidal action on the surfaces in cleanrooms it is sufficient to use a sporicidal solution with a ready-to-use concentration of 70% while ensuring a contact time of 10 min. In any case, the reduction of sporicide concentration ensures a high degree of disinfection and provides a consumption savings. Wide-spectrum disinfectants are used in the pharmaceutical industry for the decontamination of work surfaces and equipment, but these products have some degree of toxicity for operators. This work arises from the needs of pharmaceutical companies to find the lowest effective concentration of sanitizers in order to reduce toxicity to personnel. The sanitizer used in the study was a market liquid sporicide based on peracetic acid. When we started our work no similar studies were reported in the literature, so we took European regulatory agencies and USP guidelines as a starting point, employing carriers of hard, non-porous materials usually treated with the sporicidal solution and present in sterile rooms and spores of four different microorganisms. The experiments highlighted that it is sufficient to use a 70% sporicidal solution concentration with a contact time of 10 min to reduce the number of spores to acceptable values for medicinal production. The reduction of sporicide concentration both ensures a high degree of disinfection and provides a safer working environment and consumption savings.

Creep Properties of the As-Cast Al-A319 Alloy: T4 and T7 Heat Treatment Effects

NASA Astrophysics Data System (ADS)

Erfanian-Naziftoosi, Hamid R.; Rincón, Ernesto J.; López, Hugo F.

2016-08-01

In this work, the creep behavior of a commercial Al-A319 alloy was investigated in the temperature range of 413 K to 533 K (140 °C to 260 °C). Tensile creep specimens in the as-cast condition and after heat treating by solid solution (T4) and by aging (T7) were tested in a stress range varying from 60 to 170 MPa. It was found that steady-state creep strain rate was significantly low in the T7 condition when compared with either the T4 or as-cast alloy conditions. As a result, the time to failure behavior considerably increased. The experimentally determined creep exponents measured from the stress-strain curves were 4 for the as-cast alloy, 7.5 in the solid solution, and 9.5 after aging. In particular, after solid solution a grain substructure was found to develop which indicated that creep in a constant subgrain structure was active, thus accounting for the n exponent of 7.5. In the aged condition, a stress threshold is considered to account for the power law creep exponent n of 9.5. Moreover, It was found that the creep activation energy values were rather similar for the alloys in the as-cast (134 kJ/mol) and T4 (146 kJ/mol) conditions. These values are close to the one corresponding to pure Al self-diffusion (143 kJ/mol). In the aged alloy, the apparent creep activation energy (202 kJ/mol) exceeded that corresponding to Al self-diffusion. This deviation in activation energy is attributed to the effect of temperature on the alloy elastic modulus. Microstructural observations using transmission electron microscopy provided further support for the various dislocation-microstructure interactions exhibited by the alloy under the investigated creep conditions and implemented heat treatments.

Rapid post-oral stimulation of intake and flavor conditioning by glucose and fat in the mouse

PubMed Central

Zukerman, Steven; Ackroff, Karen

2011-01-01

Although widely assumed to have only satiating actions, nutrients in the gut can also condition increases in intake in some cases. Here we studied the time course of post-oral nutrient stimulation of ingestion in food-restricted C57BL/6J mice. In experiment 1, mice adapted to drink a 0.8% sucralose solution 1 h/day, rapidly increased their rate of licking (within 4–6 min) when first tested with an 8% glucose solution and even more so in tests 2 and 3. Other mice decreased their licking rate when switched from sucralose to 8% fructose, a sugar that is sweet like glucose but lacks positive post-oral effects in mice. The glucose-stimulated drinking is due to the sugar's post-oral rather than taste properties, because sucralose is highly preferred to glucose and fructose in brief choice tests. A second experiment showed that the glucose-stimulated ingestion is associated with a conditioned flavor preference in both intact and capsaicin-treated mice. This indicates that the post-oral stimulatory action of glucose is not mediated by capsaicin-sensitive visceral afferents. In experiment 3, mice consumed flavored saccharin solutions as they self-infused water or glucose via an intragastric (IG) catheter. The glucose self-infusion stimulated ingestion within 13–15 min in test 1 and produced a conditioned increase in licking that was apparent in the initial minute of tests 2 and 3. Experiment 4 revealed that IG self-infusions of a fat emulsion also resulted in post-oral stimulation of licking in test 1 and conditioned increases in tests 2 and 3. These findings indicate that glucose and fat can generate stimulatory post-oral signals early in a feeding session that increase ongoing ingestion and condition increases in flavor acceptance and preference revealed in subsequent feeding sessions. The test procedures developed here can be used to investigate the peripheral and central processes involved in stimulation of intake by post-oral nutrients. PMID:21975648

Increased water resistance of paper treated with amylose-fatty ammonium salt inclusion complexes

USDA-ARS?s Scientific Manuscript database

Amylose inclusion complexes were prepared from high amylose corn starch and the HCl salts of hexadecylamine and octadecylamine. Solutions of the complexes were applied to paper at concentrations of 2-4%. After the treated papers were dried, sodium hydroxide solution was applied to convert the adsorb...

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

Choi, Jeong

The research program reported here is focused on critical issues that represent conspicuous gaps in current understanding of rapid solidification, limiting our ability to predict and control microstructural evolution (i.e. morphological dynamics and microsegregation) at high undercooling, where conditions depart significantly from local equilibrium. More specifically, through careful application of phase-field modeling, using appropriate thin-interface and anti-trapping corrections and addressing important details such as transient effects and a velocity-dependent (i.e. adaptive) numerics, the current analysis provides a reasonable simulation-based picture of non-equilibrium solute partitioning and the corresponding oscillatory dynamics associated with single-phase rapid solidification and show that this method ismore » a suitable means for a self-consistent simulation of transient behavior and operating point selection under rapid growth conditions. Moving beyond the limitations of conventional theoretical/analytical treatments of non-equilibrium solute partitioning, these results serve to substantiate recent experimental findings and analytical treatments for single-phase rapid solidification. The departure from the equilibrium solid concentration at the solid-liquid interface was often observed during rapid solidification, and the energetic associated non-equilibrium solute partitioning has been treated in detail, providing possible ranges of interface concentrations for a given growth condition. Use of these treatments for analytical description of specific single-phase dendritic and cellular operating point selection, however, requires a model for solute partitioning under a given set of growth conditions. Therefore, analytical solute trapping models which describe the chemical partitioning as a function of steady state interface velocities have been developed and widely utilized in most of the theoretical investigations of rapid solidification. However, these solute trapping models are not rigorously verified due to the difficulty in experimentally measuring under rapid growth conditions. Moreover, since these solute trapping models include kinetic parameters which are difficult to directly measure from experiments, application of the solute trapping models or the associated analytic rapid solidification model is limited. These theoretical models for steady state rapid solidification which incorporate the solute trapping models do not describe the interdependency of solute diffusion, interface kinetics, and alloy thermodynamics. The phase-field approach allows calculating, spontaneously, the non-equilibrium growth effects of alloys and the associated time-dependent growth dynamics, without making the assumptions that solute partitioning is an explicit function of velocity, as is the current convention. In the research described here, by utilizing the phase-field model in the thin-interface limit, incorporating the anti-trapping current term, more quantitatively valid interface kinetics and solute diffusion across the interface are calculated. In order to sufficiently resolve the physical length scales (i.e. interface thickness and diffusion boundary length), grid spacings are continually adjusted in calculations. The full trajectories of transient planar growth dynamics under rapid directional solidification conditions with different pulling velocities are described. As a validation of a model, the predicted steady state conditions are consistent with the analytic approach for rapid growth. It was confirmed that rapid interface dynamics exhibits the abrupt acceleration of the planar front when the effect of the non-equilibrium solute partitioning at the interface becomes signi ficant. This is consistent with the previous linear stability analysis for the non-equilibrium interface dynamics. With an appropriate growth condition, the continuous oscillation dynamics was able to be simulated using continually adjusting grid spacings. This oscillatory dynamics including instantaneous jump of interface velocities are consistent with a previous phenomenological model by and a numerical investigation, which may cause the formation of banded structures. Additionally, the selection of the steady state growth dynamics in the highly undercooled melt is demonstrated. The transition of the growth morphology, interface velocity selection, and solute trapping phenomenon with increasing melt supersaturations was described by the phase-field simulation. The tip selection for the dendritic growth was consistent with Ivantsov's function, and the non-equilibrium chemical partitioning behavior shows good qualitative agreement with the Aziz's solute trapping model even though the model parameter(V D) remains as an arbitrary constant. This work is able to show the possibility of comprehensive description of rapid alloy growth over the entire time-dependent non-equilibrium phenomenon.« less

Crystalline hydroxyapatite coatings synthesized under hydrothermal conditions on modified titanium substrates.

PubMed

Suchanek, Katarzyna; Bartkowiak, Amanda; Gdowik, Agnieszka; Perzanowski, Marcin; Kąc, Sławomir; Szaraniec, Barbara; Suchanek, Mateusz; Marszałek, Marta

2015-06-01

Hydroxyapatite coatings were successfully produced on modified titanium substrates via hydrothermal synthesis in a Ca(EDTA)(2-) and (NH4)2HPO4 solution. The morphology of modified titanium substrates as well as hydroxyapatite coatings was studied using scanning electron microcopy and phase identification by X-ray diffraction, and Raman and FTIR spectroscopy. The results show that the nucleation and growth of hydroxyapatite needle-like crystals with hexagonal symmetry occurred only on titanium substrates both chemically and thermally treated. No hydroxyapatite phase was detected on only acid etched Ti metal. This finding demonstrates that only a particular titanium surface treatment can effectively induce the apatite nucleation under hydrothermal conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

METHOD OF RECOVERING THORIUM

DOEpatents

Fisher, R.W.

1957-12-10

A method is described for recovering thorium from impurities found in a slag containing thorium and said impurities, comprising leaching a composition containing thorium with water, removing the water solution, treating the residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting its acidity to 1 to 3 normal, adding oxalic acid, and thereafter separating the precipitated thorium oxalate digesting the residue from the hydrochloric acid treatment with a strong solution of sodium hydroxide at an elevated temperature, removing said solution and treating the insoluble residue with hydrochloric acid, separating the solution from the insoluble residue, adjusting the acidity of this solution to 1 to 3 normal, adding nitric acid to oxidize the iron present, adding oxalic acid and thereafter separating the thorium oxalate thus precipitated.

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

Cink, J.H.; Coats, J.R.

Dursban TC has become the most widely used insecticide for the control of termites since the banning of chlordane. Several laboratory studies have been conducted to investigate the degradation kinetics of chlorpyrifos applied to soil at termiticide rates. These have included a limited number of soil types and have utilized tightly regulated environmental conditions. A field study was established to investigate the degradation of chlorpyrifos in soil treated with a 1% solution via trench application and under natural environmental conditions. Once treated, soil samples were removed from the trench at scheduled intervals and extracted to determine the concentration chlorpyrifos remaining.more » In three of the soils studied, the concentration of chlorpyrifos decreased dramatically within the first three months. The remaining soils showed a steady decline in concentration over 12 months. After this initial phase of degradation, the slope of the degradation curve changed sharply. This may indicate that chlorpyrifos undergoes two phases of degradation in soil. Using both phases of the degradation curves may give a better estimate of the concentration of chlorpyrifos that may be present in a soil at any time period.« less

Investigation of Mechanical Properties and Fracture Simulation of Solution-Treated AA 5754

NASA Astrophysics Data System (ADS)

Kumar, Pankaj; Singh, Akhilendra

2017-10-01

In this work, mechanical properties and fracture toughness of as-received and solution-treated aluminum alloy 5754 (AA 5754) are experimentally evaluated. Solution heat treatment of the alloy is performed at 530 °C for 2 h, and then, quenching is done in water. Yield strength, ultimate tensile strength, impact toughness, hardness, fatigue life, brittle fracture toughness (K_{Ic} ) and ductile fracture toughness (J_{Ic} ) are evaluated for as-received and solution-treated alloy. Extended finite element method has been used for the simulation of tensile and fracture behavior of material. Heaviside function and asymptotic crack tip enrichment functions are used for modelling of the crack in the geometry. Ramberg-Osgood material model coupled with fracture energy is used to simulate the crack propagation. Fracture surfaces obtained from various mechanical tests are characterized by scanning electron microscopy.

Rapid degradation, mineralization and detoxification of pharmaceutically active compounds in aqueous solution during pulsed corona discharge treatment.

PubMed

Singh, Raj Kamal; Philip, Ligy; Ramanujam, Sarathi

2017-09-15

In the present study, plasma generated by pulsed corona discharge was used for the degradation of diclofenac, carbamazepine and ciprofloxacin. Pollutants in aqueous solution were plasma treated under two categories: single and mixed pollutant condition. Mixed pollutant condition showed an antagonistic behaviour and thus the degradation time was higher for mixed condition compared to the single condition. At different voltage and frequencies, degradation efficiency followed the trend, diclofenac>carbamazepine>ciprofloxacin. Acidic pH slightly favoured the degradation process whereas in presence of radical scavengers (HCO 3 - , CO 3 2- and humic acid) the degradation yield was significantly decreased. With an input power of 101.5 W, complete degradation was achieved within 4-16 min of plasma treatment for pharmaceutical's concentrations of 1-10 mg/L. As the pollutant concentration increased from 1 to 10 mg/L, the pseudo first order rate constant decreased, while yield increased. Complete degradation pathway of diclofenac, carbamazepine and ciprofloxacin in plasma treatment process are proposed by identifying the intermediates using LC-MS analysis. TOC analysis confirmed 80% mineralization within 10 min of plasma treatment for higher pharmaceutical's concentrations of 10 mg/L. The microalgae ecotoxicity study and disc diffusion test confirmed the complete detoxification of PACs that took place after 6 min of plasma treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Recovery of nitrogen and water from landfill leachate by a microbial electrolysis cell-forward osmosis system.

PubMed

Qin, Mohan; Molitor, Hannah; Brazil, Brian; Novak, John T; He, Zhen

2016-01-01

A microbial electrolysis cell (MEC)-forward osmosis (FO) system was previously reported for recovering ammonium and water from synthetic solutions, and here it has been advanced with treating landfill leachate. In the MEC, 65.7±9.1% of ammonium could be recovered in the presence of cathode aeration. Without aeration, the MEC could remove 54.1±10.9% of ammonium from the leachate, but little ammonia was recovered. With 2M NH4HCO3 as the draw solution, the FO process achieved 51% water recovery from the MEC anode effluent in 3.5-h operation, higher than that from the raw leachate. The recovered ammonia was used as a draw solute in the FO for successful water recovery from the treated leachate. Despite the challenges with treating returning solution from the FO, this MEC-FO system has demonstrated the potential for resource recovery from wastes, and provide a new solution for sustainable leachate management. Copyright © 2015 Elsevier Ltd. All rights reserved.

PEROXIDE PROCESS FOR SEPARATION OF RADIOACTIVE MATERIALS

DOEpatents

Seaborg, G.T.; Perlman, I.

1958-09-16

reduced state, from hexavalent uranium. It consists in treating an aqueous solution containing such uranium and plutonium ions with sulfate ions in order to form a soluble uranium sulfate complex and then treating the solution with a soluble thorium compound and a soluble peroxide compound in order to ferm a thorium peroxide carrier precipitate which carries down with it the plutonium peroxide present. During this treatment the pH of the solution must be maintained between 2 and 3.

Ocean tides for satellite geodesy

NASA Technical Reports Server (NTRS)

Dickman, S. R.

1990-01-01

Spherical harmonic tidal solutions have been obtained at the frequencies of the 32 largest luni-solar tides using prior theory of the author. That theory was developed for turbulent, nonglobal, self-gravitating, and loading oceans possessing realistic bathymetry and linearized bottom friction; the oceans satisfy no-flow boundary conditions at coastlines. In this theory the eddy viscosity and bottom drag coefficients are treated as spatially uniform. Comparison of the predicted degree-2 components of the Mf, P1, and M2 tides with those from numerical and satellite-based tide models allows the ocean friction parameters to be estimated at long and short periods. Using the 32 tide solutions, the frequency dependence of tidal admittance is investigated, and the validity of sideband tide models used in satellite orbit analysis is examined. The implications of admittance variability for oceanic resonances are also explored.

Recovery of autologous sickle cells by hypotonic wash.

PubMed

Wilson, Emily; Kezeor, Kelly; Crosby, Monica

2018-01-01

It is important to isolate autologous red blood cells (RBCs) from transfused RBCs in samples from recently transfused patients to ensure that accurate serologic results are obtained. Typically, this isolation can be performed using methods that separate patient reticulocytes from transfused, older donor RBCs. Patients with sickle cell disease (SCD), however, characteristically have RBCs with altered membrane and morphological features, causing their RBCs to take on a sickle-shape appearance different from the biconcave disc-shape appearance of "normal" RBCs. These characteristics enable the use of hypotonic saline solution to lyse normal RBCs while allowing "sickle cells" to remain intact. Because many patients with SCD undergo frequent transfusions to treat their condition, the use of hypotonic saline solution provides a rapid method to obtain autologous RBCs for serologic testing from this patient population using standard laboratory equipment and supplies.

Effect of Cr Contents and Heat Treating on Reverted Austenite in Maraging Steel Weldments

NASA Astrophysics Data System (ADS)

Kim, S. W.; Lee, H. W.

2018-05-01

By conducting flux cored arc welding (FCAW) on maraging steels with Cr contents of 1.4 and 5.2 wt%, this study observed the effects of Cr content and heat treating on reverted austenite formation in welded maraging steel. Aging treatment was carried out at the temperatures of 450, 480 and 530 °C for 3 h in each condition. As the aging temperature increased, reverted austenite was formed along the interdendritic and intercellular grain boundaries, and the proportion of reverted austenite increased with increasing Cr addition. The aging process led to the segregation of Ti and Mo along the interdendritic and intercellular grain boundaries. Some of the welded specimens were subjected to solution heat treatment at 820 and 1250 °C for 1 h after welding, resulting in a decrease in reverted austenite fraction.

An investigation of squeeze-cast alloy 718

NASA Technical Reports Server (NTRS)

Gamwell, W. R.

1993-01-01

Alloy 718 billets produced by the squeeze-cast process have been evaluated for use as potential replacements for propulsion engine components which are normally produced from forgings. Alloy 718 billets were produced using various processing conditions. Structural characterizations were performed on 'as-cast' billets. As-cast billets were then homogenized and solution treated and aged according to conventional heat-treatment practices for this alloy. Mechanical property evaluations were performed on heat-treated billets. As-cast macrostructures and microstructures varied with squeeze-cast processing parameters. Mechanical properties varied with squeeze-cast processing parameters and heat treatments. One billet exhibited a defect free, refined microstructure, with mechanical properties approaching those of wrought alloy 718 bar, confirming the feasibility of squeeze-casting alloy 718. However, further process optimization is required, and further structural and mechanical property improvements are expected with process optimization.

Effect of Cr Contents and Heat Treating on Reverted Austenite in Maraging Steel Weldments

NASA Astrophysics Data System (ADS)

Kim, S. W.; Lee, H. W.

2018-03-01

By conducting flux cored arc welding (FCAW) on maraging steels with Cr contents of 1.4 and 5.2 wt%, this study observed the effects of Cr content and heat treating on reverted austenite formation in welded maraging steel. Aging treatment was carried out at the temperatures of 450, 480 and 530 °C for 3 h in each condition. As the aging temperature increased, reverted austenite was formed along the interdendritic and intercellular grain boundaries, and the proportion of reverted austenite increased with increasing Cr addition. The aging process led to the segregation of Ti and Mo along the interdendritic and intercellular grain boundaries. Some of the welded specimens were subjected to solution heat treatment at 820 and 1250 °C for 1 h after welding, resulting in a decrease in reverted austenite fraction.

Effect of hydrogen peroxide on improving the heat stability of whey protein isolate solutions.

PubMed

Sutariya, Suresh; Patel, Hasmukh

2017-05-15

Whey protein isolate (WPI) solutions (12.8%w/w protein) were treated with varying concentrations of H 2 O 2 in the range of 0-0.144 H 2 O 2 to protein ratios (HTPR) by the addition of the required quantity of H 2 O 2 and deionized water. The samples were analyzed for heat stability, rheological properties, denaturation level of β-lactoglobulin (β-LG) and α-lactalbumin (α-LA). The samples treated with H 2 O 2 concentration >0.072 (HTPR) showed significant improvement in the heat stability, and decreased whey protein denaturation and aggregation. The WPI solution treated with H 2 O 2 (>0.072 HTPR) remained in the liquid state after heat treatment at 120°C, whereas the control samples formed gel upon heat treatment. Detailed analysis of these samples suggested that the improvement in the heat stability of H 2 O 2 treated WPI solution was attributed to the significant reduction in the sulfhydryl-disulfide interchange reaction during denaturation of β-LG and α-LA. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Feedback Control Model of Comprehensive Therapy for Treating Immunogenic Tumours

NASA Astrophysics Data System (ADS)

Tang, Biao; Xiao, Yanni; Tang, Sanyi; Cheke, Robert A.

Surgery is the traditional method for treating cancers, but it often fails to cure patients for complex reasons so new therapeutic approaches that include both surgery and immunotherapy have recently been proposed. These have been shown to be effective, clinically, in inhibiting cancer cells while allowing retention of immunologic memory. This comprehensive strategy is guided by whether a population of tumour cells has or has not exceeded a threshold density. Conditions for successful control of tumours in an immune tumour system were modeled and the related dynamics were addressed. A mathematical model with state-dependent impulsive interventions is formulated to describe combinations of surgery with immunotherapy. By analyzing the properties of the Poincaré map, we examine the global dynamics of the immune tumour system with state-dependent feedback control, including the existence and stability of the semi-trivial order-1 periodic solution and the positive order-k periodic solution. The main results showed that surgery alone can only control the tumour size below a certain level while there is no immunologic memory. If comprehensive therapy involving combining surgery with immunotherapy is considered, then not only can the cancers be controlled below a certain level, but the immune system can also retain its activity. The existence of positive order-k periodic solutions implies that periodical therapy is needed to control the cancers. However, choosing the treatment frequency and the strength of the therapy remains challenging, and hence a strategy of individual-based therapy is suggested.

Two conditions for equivalence of 0-norm solution and 1-norm solution in sparse representation.

PubMed

Li, Yuanqing; Amari, Shun-Ichi

2010-07-01

In sparse representation, two important sparse solutions, the 0-norm and 1-norm solutions, have been receiving much of attention. The 0-norm solution is the sparsest, however it is not easy to obtain. Although the 1-norm solution may not be the sparsest, it can be easily obtained by the linear programming method. In many cases, the 0-norm solution can be obtained through finding the 1-norm solution. Many discussions exist on the equivalence of the two sparse solutions. This paper analyzes two conditions for the equivalence of the two sparse solutions. The first condition is necessary and sufficient, however, difficult to verify. Although the second is necessary but is not sufficient, it is easy to verify. In this paper, we analyze the second condition within the stochastic framework and propose a variant. We then prove that the equivalence of the two sparse solutions holds with high probability under the variant of the second condition. Furthermore, in the limit case where the 0-norm solution is extremely sparse, the second condition is also a sufficient condition with probability 1.

Evaluating the Effectivenes of Antiseptic Solution Decasan in Treatment of Necrotic Soft Tisue Diseases.

PubMed

Fuss, Julia; Palii, Victor; Voloboyeva, Anna

2016-10-01

Sepsis is a severe generalised infection caused usually by pathogenic bacteria. It is often the cause of hospitalization and death in patients treated in intensive care and other hospital wards. Latest research brought to better understanding of patomechanisms, took place significant development of therapy heading to improvement of general patients condition treated as a basis and additionally supported by local therapy. The aim of the study was to evaluate the possibility of using the solution Decasan in the comprehensive treatment of patients necrosis of soft tissues. The study included 192 patients (W/M 103/89; average -aged 53.35 ± 5.36 years). According to the classification of septic states (Chicago, 1991), patients were divided into three groups: first - patients to the local form of the infection, the second - with Systemic Inflammatory Response Syndrome (SIRS), which lasted up to 72 hours and the third - patients with various forms of sepsis, SIRS in which lasted 72 hours. As a result of our studies carried out in patients where the wound was made decontamination solution Decasanu, received: pain reduction, decrease tissue swelling, early debridement of the wound and the appearance in the wound granulation, to reduce delays wound healing. Proposed algorithms treatment of various forms of sepsis, pointed out the essential elements, ie.: a comprehensive approach to the treatment of infection by early surgical intervention, intensive supportive therapy (fluid resuscitation), antibiotic therapy directed to microorganisms that cause infections and topical antiseptics therapy (solution Decasanu). The preparation antiseptic Decasan can be safely used for disinfection of skin, mucous membranes and wounds in the foci of infections caused by bacteria, fungi and protozoa.

Laboratory persistence in soil of thiacloprid, pendimethalin and fenarimol incubated with treated wastewater and dissolved organic matter solutions. Contribution of soil biota.

PubMed

Rodríguez-Liébana, José Antonio; ElGouzi, Siham; Peña, Aránzazu

2017-08-01

Reutilization of treated wastewater (TWW) in agriculture has continued to grow, especially in areas prone to frequent drought periods. One of the major aspects derived from this practice is the addition of important amounts of organic carbon (OC) that could interfere with the fate of organic contaminants in soils. This study has evaluated the impact of irrigation with a secondary TWW and dissolved OC (DOC) solutions from sewage sludge in the dissipation of thiacloprid (THC), pendimethalin (PDM) and fenarimol (FEN) in an OC-poor agricultural soil under laboratory conditions. The effect on soil microbial activity was also assessed through the measurement of dehydrogenase activity. Biotic processes were the main responsible for the degradation of the three compounds. Results showed that while THC was rapidly degraded (DT 50  ≤ 5.5 d), PDM and FEN were moderately persistent in soil (DT 50  ≥ 93 d). Incubation with TWW did not modify the decay rate of the three pesticides, but initially inhibited soil biota. Solutions of DOC did not alter the dissipation of FEN, but contrasting effects were observed for THC and PDM. Low DOC concentrations (30 mg L -1 ) accelerated THC disappearance, a fact explained by stimulation of endogenous biota rather than by the presence of exogenous microorganisms from the solution. On the other hand, high DOC concentrations (300 mg L -1 ) had more influence on the activity of microorganisms at longer times, and showed a trend to enhance the disappearance of the moderately persistent PDM. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of dry heat treatment of soft wheat flour for the production of high ratio cakes.

PubMed

Keppler, S; Bakalis, S; Leadley, C E; Sahi, S S; Fryer, P J

2018-05-01

An accurate method to heat treat flour samples has been used to quantify the effects of heat treatment on flour functionality. A variety of analytical methods has been used such as oscillatory rheology, rheomixer, solvent retention capacity tests, and Rapid Visco Analysis (RVA) in water and in aqueous solutions of sucrose, lactic acid, and sodium carbonate. This work supports the hypothesis that heat treatment facilitates the swelling of starch granules at elevated temperature. Results furthermore indicated improved swelling ability and increased interactions of flour polymers (in particular arabinoxylans) of heat treated flour at ambient conditions. The significant denaturation of the proteins was indicated by a lack of gluten network formation after severe heat treatments as shown by rheomixer traces. Results of these analyses were used to develop a possible cake flour specification. A method was developed using response surfaces of heat treated flour samples in the RVA using i) water and ii) 50% sucrose solution. This can uniquely characterise the heat treatment a flour sample has received and to establish a cake flour specification. This approach might be useful for the characterisation of processed samples, rather than by baking cakes. Hence, it may no longer be needed to bake a cake after flour heat treatment to assess the suitability of the flour for high ratio cake production, but 2 types of RVA tests suffice. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Analysis of mercerization process based on the intensity change of deconvoluted resonances of (13)C CP/MAS NMR: Cellulose mercerized under cooling and non-cooling conditions.

PubMed

Miura, Kento; Nakano, Takato

2015-08-01

The area intensity change of C1, C4, and C6 in spectrum obtained by (13)C CP/MAS NMR and the mutual relationship between their changes were examined for cellulose samples treated with various concentrations of aqueous NaOH solutions under non-cooling and cooling conditions. The area intensity of C1-up and C6-down changed cooperatively with that of C4-down which corresponds to the crystallinity of samples: "-up" and "-down" are the up- and down- field component in a splitting peak of NMR spectrum, respectively. The intensity change of C1-up starts to decrease with decreasing in that of C4-down after that of C6-down is almost complete. These changes were more clearly observed for samples treated under cooling condition. It can be suggested that their characteristic change relates closely to the change in conformation of cellulose chains by induced decrystallization and the subsequent crystallization of cellulose II, and presumed that their changes at microscopic level relate to the macroscopic morphological changes such as contraction along the length of cellulose chains and recovery along the length. Copyright © 2015 Elsevier B.V. All rights reserved.

3DFEMWATER: A three-dimensional finite element model of water flow through saturated-unsaturated media

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

Yeh, G.T.

1987-08-01

The 3DFEMWATER model is designed to treat heterogeneous and anisotropic media consisting of as many geologic formations as desired, consider both distributed and point sources/sinks that are spatially and temporally dependent, accept the prescribed initial conditions or obtain them by simulating a steady state version of the system under consideration, deal with a transient head distributed over the Dirichlet boundary, handle time-dependent fluxes due to pressure gradient varying along the Neumann boundary, treat time-dependent total fluxes distributed over the Cauchy boundary, automatically determine variable boundary conditions of evaporation, infiltration, or seepage on the soil-air interface, include the off-diagonal hydraulic conductivitymore » components in the modified Richards equation for dealing with cases when the coordinate system does not coincide with the principal directions of the hydraulic conductivity tensor, give three options for estimating the nonlinear matrix, include two options (successive subregion block iterations and successive point interactions) for solving the linearized matrix equations, automatically reset time step size when boundary conditions or source/sinks change abruptly, and check the mass balance computation over the entire region for every time step. The model is verified with analytical solutions or other numerical models for three examples.« less

Bromelain: a natural proteolytic for intra-abdominal adhesion prevention.

PubMed

Sahbaz, Ahmet; Aynioglu, Oner; Isik, Hatice; Ozmen, Ulku; Cengil, Osman; Gun, Banu Dogan; Gungorduk, Kemal

2015-02-01

Peritoneal adhesions are pathological fibrous connections between peritoneal surfaces resulting from incomplete peritoneal repair. Adhesions cause various health problems ranging from pelvic pain and bowel obstruction to infertility. To date, no effective agent exists for intra-abdominal adhesion prevention. Bromelain is the crude extract of the pineapple and it has fibrinolytic, antithrombotic, and anti-inflammatory properties. Bromelain has been shown to be effective for removing necrotic tissues and has been found to be effective for treating various wounds, inflammatory conditions, and thrombotic pathologies. In the present study, we evaluated bromelain as a novel agent for preventing intra-abdominal adhesions. Group 1 (control group): Adhesions were produced by cecal abrasion method, and no treatment was applied. Group 2 (i.p. bromelain-treated group): After adhesion formation, 10 mg/kg/BW of bromelain dissolved in 1 mL saline solution was applied intraperitoneally for 10 days. Group 3 (i.p. saline-treated group): After adhesion formation, 1 mL saline solution was applied intraperitoneally for 10 days. On postoperative day 10, all animals were sacrificed. All 30 rats survived surgery. Throughout the follow-up period, no complications were observed. Statistically significant differences were found between the groups with regards to macroscopic adhesion scores, inflammation, fibrosis and neo-vascularization (p < 0.001, <0.001, p = 0.001, p = 0.002, respectively). Macroscopic and histopathologic (inflammation, fibrosis, neo-vascularization) adhesion scores were lowest in the bromelain-treated group. Bromelain, acting through its barrier, anti-inflammatory, antioxidant, and proteolytic effects and without increasing bleeding tendency or having any adverse effects on wound healing, may be a suitable agent for intra-abdominal adhesion prevention. Copyright © 2015 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

An activated carbon fiber cathode for the degradation of glyphosate in aqueous solutions by the Electro-Fenton mode: Optimal operational conditions and the deposition of iron on cathode on electrode reusability.

PubMed

Lan, Huachun; He, Wenjing; Wang, Aimin; Liu, Ruiping; Liu, Huijuan; Qu, Jiuhui; Huang, C P

2016-11-15

An activated carbon fiber (ACF) cathode was fabricated and used to treat glyphosate containing wastewater by the Electro-Fenton (EF) process. The results showed that glyphosate was rapidly and efficiently degraded and the BOD 5 /COD ratio was increased to >0.3 implying the feasibility of subsequent treatment of the treated wastewater by biological methods. The results of ion chromatography and HPLC measurements indicated that glyphosate was completely decomposed. Effective OH generation and rapid recycling/recovery of the Fe 2+ ions at the cathode were responsible primarily for the high performance of the ACF-EF process. Factors such as inlet oxygen gas flow rate, Fe 2+ dosage, initial glyphosate concentration, applied current intensity, and solution pH that may affect the efficiency of the ACF-EF process were further studied and the optimum operation condition was established. Results of SEM/EDX, BET and XPS analysis showed the deposition of highly dispersed fine Fe 2 O 3 particles on the ACF surface during the EF reaction. The possibility of using the Fe 2 O 3 -ACF as iron source in the EF process was assessed. Results showed that the Fe 2 O 3 -ACF electrode was effective in degrading glyphosate in the EF process. The deposition of Fe 2 O 3 particles on the ACF electrode had no adverse effect on the reusability of the ACF cathode. Copyright © 2016. Published by Elsevier Ltd.

Pretreatment Solution for Water Recovery Systems

NASA Technical Reports Server (NTRS)

Muirhead, Dean (Inventor)

2018-01-01

Chemical pretreatments are used to produce usable water by treating a water source with a chemical pretreatment that contains a hexavalent chromium and an acid to generate a treated water source, wherein the concentration of sulfate compounds in the acid is negligible, and wherein the treated water source remains substantially free of precipitates after the addition of the chemical pretreatment. Other methods include reducing the pH in urine to be distilled for potable water extraction by pretreating the urine before distillation with a pretreatment solution comprising one or more acid sources selected from a group consisting of phosphoric acid, hydrochloric acid, and nitric acid, wherein the urine remains substantially precipitate free after the addition of the pretreatment solution. Another method described comprises a process for reducing precipitation in urine to be processed for water extraction by mixing the urine with a pretreatment solution comprising hexavalent chromium compound and phosphoric acid.

Acid-Base and Plasma Biochemical Changes Using Crystalloid Fluids in Stranded Juvenile Loggerhead Sea Turtles (Caretta caretta).

PubMed

Camacho, María; Quintana, María Del Pino; Calabuig, Pascual; Luzardo, Octavio P; Boada, Luis D; Zumbado, Manuel; Orós, Jorge

2015-01-01

The aim of this study was to compare the efficacy and effects on acid-base and electrolyte status of several crystalloid fluids in 57 stranded juvenile loggerhead turtles. Within a rehabilitation program four different crystalloid fluids were administered (0.9% Na Cl solution; 5% dextrose + 0.9% Na Cl solutions 1:1; 0.9% Na Cl + lactated Ringer's solutions 1:1; lactated Ringer's solution). Crystalloid fluids were intracoelomically administered during three days (20 ml/kg/day). Animals were sampled at three different moments: Upon admission for evaluating the type of acid-base or biochemical disorder, post-fluid therapy treatment for controlling the evolution of the disorder, and post-recovery period for obtaining the baseline values for rehabilitated loggerhead turtles. Each sample was analyzed with a portable electronic blood analyzer for pH, pO2, pCO2, lactate, sodium, potassium, chloride, glucose, and BUN concentration. Admission and post-fluid therapy treatment values were compared with those obtained for each turtle immediately before release. The highest percentage of acid-base recovery and electrolyte balance was observed in turtles treated with mixed saline-lactated Ringer's solution (63.6%), followed by turtles treated with physiological saline solution (55%), lactated Ringer's solution (33.3%), and dextrose-saline solutions (10%). Most turtles treated with lactated Ringer's solution had lower lactate concentrations compared with their initial values; however, 66.6% of turtles treated with lactated Ringer's solution had metabolic alkalosis after therapy. Significant higher concentrations of glucose were detected after saline-dextrose administration compared with all the remaining fluids. This is the first study evaluating the effects of several crystalloid fluids on the acid-base status and plasma biochemical values in stranded loggerhead sea turtles. Reference convalescent venous blood gas, acid-base, and plasma biochemical values, useful for veterinary surgeons involved in sea turtle conservation, are also provided.

Retention modeling under organic modifier gradient conditions in ion-pair reversed-phase chromatography. Application to the separation of a set of underivatized amino acids.

PubMed

Pappa-Louisi, A; Agrafiotou, P; Papachristos, K

2010-07-01

The combined effect of the ion-pairing reagent concentration, C(ipr), and organic modifier content, phi, on the retention under phi-gradient conditions at different constant C(ipr) was treated in this study by using two approaches. In the first approach, the prediction of the retention time of a sample solute is based on a direct fitting procedure of a proper retention model to 3-D phi-gradient retention data obtained under the same phi-linear variation but with different slope and time duration of the initial isocratic part and in the presence of various constant C(ipr) values in the eluent. The second approach is based on a retention model describing the combined effect of C(ipr) and phi on the retention of solutes in isocratic mode and consequently analyzes isocratic data obtained in mobile phases containing different C(ipr) values. The effectiveness of the above approaches was tested in the retention prediction of a mixture of 16 underivatized amino acids using mobile phases containing acetonitrile as organic modifier and sodium dodecyl sulfate as ion-pairing reagent. From these approaches, only the first one gives satisfactory predictions and can be successfully used in optimization of ion-pair chromatographic separations under gradient conditions. The failure of the second approach to predict the retention of solutes in the gradient elution mode in the presence of different C(ipr) values was attributed to slow changes in the distribution equilibrium of ion-pairing reagents caused by phi-variation.

[Method of component assay of alpha-glucosyltransferase-treated stevia (enzymatically modified stevia) products using enzymatic hydrolysis].

PubMed

Hirata, Keiko; Shimamura, Yasuhiro; Suzuki, Keiko; Sadamasu, Yuki; Ito, Koichi

2005-12-01

We have developed an analytical method for components of alpha-glucosyltransferase-treated stevia, a food additive product. Suitable conditions to separate additional sugar from alpha-glucosyltransferase-treated stevia by using glucoamylase were found (55 degrees C for 3 hr with 250 U of glucoamylase in 10 mL of reaction solution). By solid-phase extraction using a C18 cartridge column, polysaccharides were excluded from the sample, and the glycosides and sugar obtained after hydrolysis with glucoamylase were separated on another C18 cartridge column. The glycosides and sugar contents were determined by HPLC. By this method, additional sugar was detected in all of three product samples tested and the sugar was glucose. The contents of glucose and total glycosides (minus unreacted glycoside) were 25-42% and 35.7-52.5%, respectively. In alpha-glucosyltransferase-treated stevia, the sum of total glycosides and glucose amounted to 77.5-80.4% of the total and their recoveries from samples from which polysaccharide had been excluded by C18 cartridge column processing were over 85%. The contents of alpha-glucosyltransferase-treated stevia obtained by multiplying the sugar content by the coefficient (0.9) for hydrolysis and converting on dry weight basis were all over 80.0% and met the standard set by the Japan Food Additives Association.

Novel small interfering RNA-containing solution protecting donor organs in heart transplantation.

PubMed

Zheng, Xiufen; Lian, Dameng; Wong, Arthur; Bygrave, Michael; Ichim, Thomas E; Khoshniat, Mahdieh; Zhang, Xusheng; Sun, Hongtao; De Zordo, Tobias; Lacefield, James C; Garcia, Bertha; Jevnikar, Anthony M; Min, Wei-Ping

2009-09-22

Ischemia/reperfusion injury is a major factor in graft quality and subsequent function in the transplantation setting. We hypothesize that the process of RNA interference may be used to "engineer" a graft to suppress expression of genes associated with inflammation, apoptosis, and complement, which are believed to cause ischemia/reperfusion injury. Such manipulation of pathological gene expression may be performed by treatment of the graft ex vivo with small interfering RNA (siRNA) as part of the preservation procedure. Heart grafts from BALB/c mice were preserved in UW solution (control) or UW solution containing siRNAs targeting tumor necrosis factor-alpha, C3, and Fas genes (siRNA solution) at 4 degrees C for 48 hours and subsequently transplanted into syngeneic recipients. Tumor necrosis factor-alpha, C3, and Fas genes were elevated by ischemia/reperfusion injury after 48 hours of preservation in UW solution. Preservation in siRNA solution knocked down gene expression at the level of messenger RNA and protein in the grafts after transplantation. All grafts preserved in siRNA solution showed strong contraction, whereas grafts preserved in control solution demonstrated no detectable contraction by high-frequency ultrasound scanning. siRNA solution-treated organs exhibited improved histology and diminished neutrophil and lymphocyte infiltration compared with control solution-treated organs. Furthermore, the treated heart grafts retained strong beating up to the end of the observation period (>100 days), whereas all control grafts lost function within 8 days. Incorporation of siRNA into organ storage solution is a feasible and effective method of attenuating ischemia/reperfusion injury, protecting cardiac function, and prolonging graft survival.

Solar photo-Fenton mineralization of antipyrine in aqueous solution.

PubMed

Durán, A; Monteagudo, J M; Sanmartín, I; Carrasco, A

2013-11-30

The mineralization of an aqueous solution of antipyrine (C11H12N2O), an emerging contaminant, using a solar photocatalytic oxidation process assisted with ferrioxalate was evaluated in a compound parabolic collector (CPC) pilot plant. Under the selected operating conditions ([H2O2] = 250 ppm, [Fe] = 14 ppm, pH = 2.7, and [(COOH)2·2H2O] = 80 ppm), 60% of TOC is removed just 5 min after treating an aqueous solution containing 50 ppm of antipyrine. The addition of oxalic acid up to a maximum concentration of 80 ppm significantly increases the mineralization rate during the first 15 min of the reaction. The synergism between the solar and dark H2O2/ferrioxalate process was quantified at 79%, calculated from the pseudo first-order mineralization rate constants. The operational costs due to the consumption of electrical energy, reagents and catalysts were calculated from the optimal conditions and compared with a novel sono-photocatalytic process using artificial UV-light. The results showed that the ferrioxalate-assisted solar photo-Fenton process was economically feasible, being able to achieve up to 60% mineralization with a total cost of 4.5 cent €/g TOC removed (1.1 €/m(3)). Copyright © 2013 Elsevier Ltd. All rights reserved.

Phosphate removal by refined aspen wood fiber treated with carboxymethyl cellulose and ferrous chloride

Treesearch

Thomas L. Eberhardt; Soo-Hong Min; James S. Han

2006-01-01

Biomass-based filtration media are of interest as an economical means to remove pollutants and nutrients found in stormwater runoff. Refined aspen wood fiber samples treated with iron salt solutions demonstrated limited capacities to remove (ortho)phosphate from test solutions. To provide additional sites for iron complex formation, and thereby impart a greater...

New Approach to Remove Metals from Chromated Copper Arsenate (CCA)-Treated Wood

Treesearch

Todd F. Shupe; Chung Y. Hse; Hui Pan

2012-01-01

Recovery of metals from chromated copper arsenate (CCA)-treated southern pine wood particles was investigated using binary acid solutions consisting of acetic, oxalic, and phosphoric acids in a microwave reactor. Formation of an insoluble copper oxalate complex in the binary solution containing oxalic acid was the major factor for low copper removal. Furthermore, the...

Hydraulic permeability of bentonite-polymer composites for application in landfill technology

NASA Astrophysics Data System (ADS)

Dehn, Hanna; Haase, Hanna; Schanz, Tom

2015-04-01

Bentonites are often used as barrier materials in landfill technology to prevent infiltration of leachates to the natural environment. Since decades, geoenvironmental engineering aims at improving the hydro-mechanical performance of landfill liners. Various studies on the permeability performance of geosynthetic clay liners (GCLs) show effects of non-standard liquids on behaviour of Na+-bentonite regarding its sealing capacity. With increasing concentration of chemical aggressive solutions the sealing capacity decreases (Shackelford et al. 2000). An opportunity to improve the hydraulic permeability of the bentonites is the addition of polymers. The changes in hydraulic permeability performance of polymer treated and untreated bentonites while adding chemical aggressive solutions were studied by several authors. Results obtained by Scalia et al. (2014) illustrate that an increase in permeability can be prevented by adding polymer to Na+-bentonite. On the other hand, Ashmawy et al. (2002) presented results on the incapability of several commercial bentonite-polymer-products. The objective of this study is to characterize the influence of polymer addition on hydraulic performance of Na+-bentonite systematically. Therefore, the influence of 1% polymer addition of cationic and anionic polyacrylamide on the swelling pressure and hydraulic permeability of MX 80 bentonite was investigated. Preparation of bentonite-polymer composites was conducted (1) in dry conditions and (2) using solution-intercalation method. Experiments on hydraulic permeability were carried out using distilled water as well as CaCl2-solution. References Ashmawy, A. K., El-Hajji, D., Sotelo, N. & Muhammad, N. (2002), `Hydraulic Performance of Untreated and Polymer-treated Bentonite in Inorganic Landfill Leachates', Clays and Clay Minerals 50(5), 546-552. Scalia, J., Benson, C., Bohnhoff, G., Edil, T. & Shackelford, C. (2014), 'Long-Term Hydraulic Conductivity of a Bentonite-Polymer Composite Permeated with Aggressive Inorganic Solutions', Journal of Geotechnical and Geoenvironmental Engineering 140(3). Shackelford, C. D., Benson, C. H., Katsumi, T., Edil, T. B. & Lin, L. (2000), 'Evaluating the hydraulic conductivity of GCLs permeated with non-standard liquids', Geotextiles and Geomembranes 18, 133-161.

Physician Satisfaction in Treating Medically Unexplained Symptoms.

PubMed

Brauer, Simon G; Yoon, John D; Curlin, Farr A

2017-05-01

To determine whether treating conditions having medically unexplained symptoms is associated with lower physician satisfaction and higher ascribed patient responsibility, and to determine whether higher ascribed patient responsibility is associated with lower physician satisfaction in treating a given condition. We surveyed a nationally representative sample of 1504 US primary care physicians. Respondents were asked how responsible patients are for two conditions with more-developed medical explanations (depression and anxiety) and two conditions with less-developed medical explanations (chronic back pain and fibromyalgia), and how much satisfaction they experienced in treating each condition. We used Wald tests to compare mean satisfaction and ascribed patient responsibility between medically explained conditions and medically unexplained conditions. We conducted single-level and multilevel ordinal logistic models to test the relation between ascribed patient responsibility and physician satisfaction. Treating medically unexplained conditions elicited less satisfaction than treating medically explained conditions (Wald P < 0.001). Physicians attribute significantly more patient responsibility to the former (Wald P < 0.005), although the magnitude of the difference is small. Across all four conditions, physicians reported experiencing less satisfaction when treating symptoms that result from choices for which patients are responsible (multilevel odds ratio 0.57, P = 0.000). Physicians experience less satisfaction in treating conditions characterized by medically unexplained conditions and in treating conditions for which they believe the patient is responsible.

PROCESS FOR THE PURIFICATION OF URANIUM

DOEpatents

Rosenfeld, S.

1959-01-20

A proccss is described for reclaiming uranium values from aqueous solutions containing U, Fe, Ni, Cu, and Cr comprising treating the solution with NH/sub 3/ to precipitate the: U, Fc, and Cr and leaving Cu and Ni in solution as ammonia complex ions. The precipitate is chlorinated with CCl/sub 4/ at an elevated temperature to convert the U, Tc, and Cr into their chlorides. The more volatile FeCl/sub 3/ and CrCl/sub 3/ are separated from the UCl/sub 4/. The process is used when U is treated in a calutron, and composite solutions are produccd which contain dissolved products of stainless steel.

Salicylic acid peels versus Jessner's solution for acne vulgaris: a comparative study.

PubMed

Bae, Byung Gi; Park, Chang Ook; Shin, Hyoseung; Lee, Soo Hyun; Lee, Yun Sun; Lee, Sang Ju; Chung, Kee Yang; Lee, Kwang Hoon; Lee, Ju Hee

2013-02-01

Salicylic acid was recently formulated in a hydroethanolic vehicle at a concentration of 20% to 30%. Salicylic acid has strong comedolytic effects because of its lipophilic nature. To compare the therapeutic efficacy and tolerability of salicylic acid peels with those of Jessner's solution peels in patients with acne vulgaris. Thirteen patients (13 men; mean age 22.6, range 20-28) with facial acne were enrolled. Jessner's solution was applied to one side of each patient's face and 30% salicylic acid to the other in three sessions at 2-week intervals. A blinded investigator counted noninflammatory and inflammatory lesions before treatment and 2 weeks after each treatment. Inflammatory and noninflammatory acne lesion counts decreased in proportion to the duration of treatment. Inflammatory acne lesion counts did not differ significantly between salicylic acid and Jessner's solution peels, although in terms of noninflammatory acne lesion counts, sites treated with salicylic acid showed significant improvement (p = .04), whereas those treated with Jessner's solution did not. We found that 30% salicylic acid peels were effective for inflammatory acne and more effective than Jessner's solution peels for treating noninflammatory acne. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

Nonideal Solute Chemical Potential Equation and the Validity of the Grouped Solute Approach for Intracellular Solution Thermodynamics.

PubMed

Zielinski, Michal W; McGann, Locksley E; Nychka, John A; Elliott, Janet A W

2017-11-22

The prediction of nonideal chemical potentials in aqueous solutions is important in fields such as cryobiology, where models of water and solute transport-that is, osmotic transport-are used to help develop cryopreservation protocols and where solutions contain many varied solutes and are generally highly concentrated and thus thermodynamically nonideal. In this work, we further the development of a nonideal multisolute solution theory that has found application across a broad range of aqueous systems. This theory is based on the osmotic virial equation and does not depend on multisolute data. Specifically, we derive herein a novel solute chemical potential equation that is thermodynamically consistent with the existing model, and we establish the validity of a grouped solute model for the intracellular space. With this updated solution theory, it is now possible to model cellular osmotic behavior in nonideal solutions containing multiple permeating solutes, such as those commonly encountered by cells during cryopreservation. In addition, because we show here that for the osmotic virial equation the grouped solute approach is mathematically equivalent to treating each solute separately, multisolute solutions in other applications with fixed solute mass ratios can now be treated rigorously with such a model, even when all of the solutes cannot be enumerated.

Metabolic Capabilities of the Members of the Order Halanaerobiales and Their Potential Biotechnological Applications

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

Roush, Daniel W; Elias, Dwayne A; Mormile, Dr. Melanie R.

The order Halanaerobiales contains a number of well-studied halophiles that possess great potential for biotechnological applications. The unique halophilic adaptations that these organisms utilize, such as salting-in mechanisms to increase their intercellular concentration of KCl, combined with their ability to ferment simple sugars, provides an excellent platform for biotechnological development over a wide range of salt levels and possible other extreme conditions, such as alkaline conditions. From fermented foods to oil reservoirs, members of Halanaerobiales are found in many environments. The environmental conditions many of these organisms grow are similar to industrially important processes, such as alkaline pre-treated biomass stocks,more » treatment of crude glycerol from biodiesel production, salty fermented foods, as well as bioremediation of contaminants under extreme conditions of salinity and in some cases, alkalinity. From salt stable enzymes to waste fermentations, bioremediation options, bioenergy, and microbially enhanced oil recovery (MEOR), Halanaerobiales can provide a wide spectrum of environmentally friendly solutions to current problems.« less

Numerical solution to the oblique derivative boundary value problem on non-uniform grids above the Earth topography

NASA Astrophysics Data System (ADS)

Medl'a, Matej; Mikula, Karol; Čunderlík, Róbert; Macák, Marek

2018-01-01

The paper presents a numerical solution of the oblique derivative boundary value problem on and above the Earth's topography using the finite volume method (FVM). It introduces a novel method for constructing non-uniform hexahedron 3D grids above the Earth's surface. It is based on an evolution of a surface, which approximates the Earth's topography, by mean curvature. To obtain optimal shapes of non-uniform 3D grid, the proposed evolution is accompanied by a tangential redistribution of grid nodes. Afterwards, the Laplace equation is discretized using FVM developed for such a non-uniform grid. The oblique derivative boundary condition is treated as a stationary advection equation, and we derive a new upwind type discretization suitable for non-uniform 3D grids. The discretization of the Laplace equation together with the discretization of the oblique derivative boundary condition leads to a linear system of equations. The solution of this system gives the disturbing potential in the whole computational domain including the Earth's surface. Numerical experiments aim to show properties and demonstrate efficiency of the developed FVM approach. The first experiments study an experimental order of convergence of the method. Then, a reconstruction of the harmonic function on the Earth's topography, which is generated from the EGM2008 or EIGEN-6C4 global geopotential model, is presented. The obtained FVM solutions show that refining of the computational grid leads to more precise results. The last experiment deals with local gravity field modelling in Slovakia using terrestrial gravity data. The GNSS-levelling test shows accuracy of the obtained local quasigeoid model.

Lectures series in computational fluid dynamics

NASA Technical Reports Server (NTRS)

Thompson, Kevin W.

1987-01-01

The lecture notes cover the basic principles of computational fluid dynamics (CFD). They are oriented more toward practical applications than theory, and are intended to serve as a unified source for basic material in the CFD field as well as an introduction to more specialized topics in artificial viscosity and boundary conditions. Each chapter in the test is associated with a videotaped lecture. The basic properties of conservation laws, wave equations, and shock waves are described. The duality of the conservation law and wave representations is investigated, and shock waves are examined in some detail. Finite difference techniques are introduced for the solution of wave equations and conservation laws. Stability analysis for finite difference approximations are presented. A consistent description of artificial viscosity methods are provided. Finally, the problem of nonreflecting boundary conditions are treated.

Improvement of analytical dynamic models using modal test data

NASA Technical Reports Server (NTRS)

Berman, A.; Wei, F. S.; Rao, K. V.

1980-01-01

A method developed to determine maximum changes in analytical mass and stiffness matrices to make them consistent with a set of measured normal modes and natural frequencies is presented. The corrected model will be an improved base for studies of physical changes, boundary condition changes, and for prediction of forced responses. The method features efficient procedures not requiring solutions of the eigenvalue problem, and the ability to have more degrees of freedom than the test data. In addition, modal displacements are obtained for all analytical degrees of freedom, and the frequency dependence of the coordinate transformations is properly treated.

Design data for brazed Rene 41 honeycomb sandwich

NASA Technical Reports Server (NTRS)

Hepler, A. K.; Arnquist, J.; Koetje, E. L.; Esposito, J. J.; Lindsay, V. E. J.; Swegle, A. R.

1981-01-01

Strength data, creep data and residual strength data after cyclic thermal exposure were obtained at temperatures from 78 K to 1144 K (-320 F to 1600 F). The influences of face thickness, core depth, core gage, cell size and thermal/stress exposure conditions on the mechanical design properties were investigated. A braze alloy and process was developed that is adequate to fully develop the strength of the honeycomb core while simultaneously solution treating and aging the Rene 41 fact sheets. New test procedures and test specimen configurations were developed to avoid excessive thermal stresses during cyclic thermal exposure.

Treatment of concentrated industrial wastewaters originating from oil shale and the like by electrolysis polyurethane foam interaction

DOEpatents

Tiernan, Joan E.

1990-01-01

Highly concentrated and toxic petroleum-based and synthetic fuels wastewaters such as oil shale retort water are treated in a unit treatment process by electrolysis in a reactor containing oleophilic, ionized, open-celled polyurethane foams and subjected to mixing and laminar flow conditions at an average detention time of six hours. Both the polyurethane foams and the foam regenerate solution are re-used. The treatment is a cost-effective process for waste-waters which are not treatable, or are not cost-effectively treatable, by conventional process series.

Generation of dynamo magnetic fields in protoplanetary and other astrophysical accretion disks

NASA Technical Reports Server (NTRS)

Stepinski, T. F.; Levy, E. H.

1988-01-01

A computational method for treating the generation of dynamo magnetic fields in astrophysical disks is presented. The numerical difficulty of handling the boundary condition at infinity in the cylindrical disk geometry is overcome by embedding the disk in a spherical computational space and matching the solutions to analytically tractable spherical functions in the surrounding space. The lowest lying dynamo normal modes for a 'thick' astrophysical disk are calculated. The generated modes found are all oscillatory and spatially localized. Tha potential implications of the results for the properties of dynamo magnetic fields in real astrophysical disks are discussed.

Electrolyte Solutions and Specific Ion Effects on Interfaces

ERIC Educational Resources Information Center

Friedman, Ran

2013-01-01

Introductory general and physical chemistry courses often deal with colligative properties of solutions and do not discuss nonideal solutions in detail. Yet, a growing body of evidence reveals that even at physiological concentrations electrolyte solutions cannot be treated as ideal when a charged or partially charged solute (such as a protein) is…

Quality of osmotically pre-treated and vacuum dried pineapple cubes on storage as influenced by type of solutes and packaging materials.

PubMed

Paul, Prodyut Kumar; Ghosh, Swapan Kumar; Singh, Dhananjay Kumar; Bhowmick, Nilesh

2014-08-01

The quality and stability of osmotically pre-treated and subsequently vacuum dried pineapple cubes using three different solutes and packed in three different types of packaging materials on storage was evaluated. The experiment was laid out in completely randomized block design with two factors and three replications for each treatment. Treatment combinations were considered as one factor and storage interval as another factor. Pineapple cubes stored in glass bottle showed very little percentage variation in moisture content due to its high moisture barrier properties. In all treatment combination, acidity values were invariably found to increase as the storage progressed. For all three different osmotic treatments, HDPE pouch packet always showed highest acidity followed by PVDC pouch. Again among three solutes under consideration, invert sugar recorded a rapid increase in acidity than other solutes. In pineapple cubes osmotically treated with sucrose solution, the rates of decrease of total sugar content were lower than that of invert sugar and sorbitol treated pineapple cubes. The percentage decrease of total sugar content was highest when the osmotically dehydrated pineapple cubes were packed in HDPE pouch and it was least in glass bottles. There was a gradual decrease in ascorbic acid content with the extension of storage period and this decrease was statistically significant at all storage intervals up to six-month. Lowest value of ascorbic acid content (15.210 mg per 100 g initial solid) was recorded in invert sugar treated pineapple cube packed in HDPE pouch after 6 months of storage.

Modified resins for solid-phase extraction

DOEpatents

Fritz, James S.; Sun, Jeffrey J.

1993-07-27

A process of treating aqueous solutions to remove organic solute contaminants by contacting an aqueous solution containing polar organic solute contaminants with a functionalized polystyrene-divinyl benzene adsorbent resin, with the functionalization of said resin being accomplished by organic hydrophilic groups such as hydroxymethyl, acetyl and cyanomethyl.

Modified resins for solid-phase extraction

DOEpatents

Fritz, James S.; Sun, Jeffrey J.

1991-12-10

A process of treating aqueous solutions to remove organic solute contaminants by contacting an aqueous solution containing polar organic solute contaminants with a functionalized polystyrene-divinyl benzene adsorbent resin, with the functionalization of said resin being accomplished by organic hydrophilic groups such as hydroxymethyl, acetyl and cyanomethyl.

Effects of adaptive refinement on the inverse EEG solution

NASA Astrophysics Data System (ADS)

Weinstein, David M.; Johnson, Christopher R.; Schmidt, John A.

1995-10-01

One of the fundamental problems in electroencephalography can be characterized by an inverse problem. Given a subset of electrostatic potentials measured on the surface of the scalp and the geometry and conductivity properties within the head, calculate the current vectors and potential fields within the cerebrum. Mathematically the generalized EEG problem can be stated as solving Poisson's equation of electrical conduction for the primary current sources. The resulting problem is mathematically ill-posed i.e., the solution does not depend continuously on the data, such that small errors in the measurement of the voltages on the scalp can yield unbounded errors in the solution, and, for the general treatment of a solution of Poisson's equation, the solution is non-unique. However, if accurate solutions the general treatment of a solution of Poisson's equation, the solution is non-unique. However, if accurate solutions to such problems could be obtained, neurologists would gain noninvasive accesss to patient-specific cortical activity. Access to such data would ultimately increase the number of patients who could be effectively treated for pathological cortical conditions such as temporal lobe epilepsy. In this paper, we present the effects of spatial adaptive refinement on the inverse EEG problem and show that the use of adaptive methods allow for significantly better estimates of electric and potential fileds within the brain through an inverse procedure. To test these methods, we have constructed several finite element head models from magneteic resonance images of a patient. The finite element meshes ranged in size from 2724 nodes and 12,812 elements to 5224 nodes and 29,135 tetrahedral elements, depending on the level of discretization. We show that an adaptive meshing algorithm minimizes the error in the forward problem due to spatial discretization and thus increases the accuracy of the inverse solution.

Methods for treating a liquid using draw solutions

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

Wilson, Aaron D; Orme, Christopher J.

Draw solutions comprising at least one N-cyclicalkyl-cycloalkylamine and a secondary solvent. The N-cyclicalkyl-cycloalkylamine comprises the chemical structure: ##STR00001## wherein n is 0, 1, or 2, n' is 0, 1, or 2, and each of R.sup.1-R.sup.6 is independently selected from the group consisting of an alkyl group, an alkoxy group, an acetyl group, an aryl group, a hydrogen group, a hydroxyl group, and a phosphorus-containing group. Methods of treating a liquid using the draw solution are also disclosed.

Step-wise supercritical extraction of carbonaceous residua

DOEpatents

Warzinski, Robert P.

1987-01-01

A method of fractionating a mixture containing high boiling carbonaceous material and normally solid mineral matter includes processing with a plurality of different supercritical solvents. The mixture is treated with a first solvent of high critical temperature and solvent capacity to extract a large fraction as solute. The solute is released as liquid from solvent and successively treated with other supercritical solvents of different critical values to extract fractions of differing properties. Fractionation can be supplemented by solute reflux over a temperature gradient, pressure let down in steps and extractions at varying temperature and pressure values.

Mechanical properties of moso bamboo treated with chemical agents

Treesearch

Benhua Fei; Zhijia Liu; Zehui Jiang; Zhiyong Cai

2013-01-01

Bamboo is a type of biomass material and has great potential as a bioenergy resource for the future in China. Surface chemical and thermal–mechanical behavior play an important role in the manufacturing process of bamboo composites and pellets. In this study, moso bamboo was treated by sodium hydrate solution and acetic acid solution. Surface chemical and dynamic...

Detox{sup SM} wet oxidation system studies for engineering scale up

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

Robertson, D.T.; Moslander, J.E.; Zigmond, J.A.

1995-12-31

Catalyzed wet oxidation utilizing iron(III) has been shown to have promise for treating many hazardous and mixed wastes. The reaction occurs at the surface of contact between an aqueous iron(III) solution and organic material. Studies with liquid- and vapor-phase organic waste surrogates have established reaction kinetics and the limits of reaction rate based on organic concentration and iron(III) diffusion. Continuing engineering studies have concentrated on reaction vessel agitator and solids feed configurations, an improved bench scale reflux condenser and reflux condenser calculations, sparging of organic compounds from the process condensate water, filtration of solids from the process solution, and flammabilitymore » limits for volatile organic compounds in the headspace of the reaction vessel under the reaction conditions. Detailed engineering design and fabrication of a demonstration unit for treatment of mixed waste is in progress.« less

An approximation theory for the identification of nonlinear distributed parameter systems

NASA Technical Reports Server (NTRS)

Banks, H. T.; Reich, Simeon; Rosen, I. G.

1988-01-01

An abstract approximation framework for the identification of nonlinear distributed parameter systems is developed. Inverse problems for nonlinear systems governed by strongly maximal monotone operators (satisfying a mild continuous dependence condition with respect to the unknown parameters to be identified) are treated. Convergence of Galerkin approximations and the corresponding solutions of finite dimensional approximating identification problems to a solution of the original finite dimensional identification problem is demonstrated using the theory of nonlinear evolution systems and a nonlinear analog of the Trotter-Kato approximation result for semigroups of bounded linear operators. The nonlinear theory developed here is shown to subsume an existing linear theory as a special case. It is also shown to be applicable to a broad class of nonlinear elliptic operators and the corresponding nonlinear parabolic partial differential equations to which they lead. An application of the theory to a quasilinear model for heat conduction or mass transfer is discussed.

Effects of artificial sweeteners on body weight, food and drink intake.

PubMed

Polyák, Eva; Gombos, K; Hajnal, B; Bonyár-Müller, K; Szabó, Sz; Gubicskó-Kisbenedek, A; Marton, K; Ember, I

2010-12-01

Artificial sweeteners are widely used all over the world. They may assist in weight management, prevention of dental caries, control of blood glucose of diabetics, and also can be used to replace sugar in foods. In the animal experimentation mice were given oral doses of water solutions of table top artificial sweeteners (saccharin, cyclamate based, acesulfame-K based, and aspartame) the amount of maximum Acceptable Daily Intake (ADI) ad libitum. The controls received only tap water with the same drinking conditions as the treated groups. The mice were fed chow ad libitum.We measured food intake and body weight once a week, water and solutions of artificial sweeteners intake twice a week. The data were analysed by statistical methods (T-probe, regression analysis).Consumption of sweeteners resulted in significantly increased body weight; however, the food intake did not change.These results question the effect of non-caloric artificial sweeteners on weight-maintenance or body weight decrease.

Decay of solutions of the wave equation with arbitrary localized nonlinear damping

NASA Astrophysics Data System (ADS)

Bellassoued, Mourad

We study the problem of decay rate for the solutions of the initial-boundary value problem to the wave equation, governed by localized nonlinear dissipation and without any assumption on the dynamics (i.e., the control geometric condition is not satisfied). We treat separately the autonomous and the non-autonomous cases. Providing regular initial data, without any assumption on an observation subdomain, we prove that the energy decays at last, as fast as the logarithm of time. Our result is a generalization of Lebeau (in: A. Boutet de Monvel, V. Marchenko (Eds.), Algebraic and Geometric Methods in Mathematical Physics, Kluwer Academic Publishers, Dordrecht, the Netherlands, 1996, pp. 73) result in the autonomous case and Nakao (Adv. Math. Sci. Appl. 7 (1) (1997) 317) work in the non-autonomous case. In order to prove that result we use a new method based on the Fourier-Bross-Iaglintzer (FBI) transform.

Biogeochemistry in highly reduced mussel farm sediments during macrofaunal recolonization by Amphiura filiformis and Nephtys sp.

PubMed

Lindqvist, Stina; Norling, Karl; Hulth, Stefan

2009-04-01

Mussel farming is considered a viable means for reducing coastal eutrophication. This study assessed the importance of bioturbation by recolonizing fauna for benthic solute fluxes and porewater distributions in manipulated mussel farm sediments. Three consecutive time-series flux incubations were performed during an experimental period of three weeks in sieved farm sediment treated with the brittle star Amphiura filiformis and the polychaete Nephtys sp. The functional behavior of Nephtys sp. and interactions between Nephtys sp. and the spontaneously colonizing spionid Malacoceros fuliginosus determined the biogeochemical response in the Nephtys sp. treatment. For example, the oxic zone was restricted and benthic nitrate and silicate fluxes were reduced compared to the brittle star treatment. A. filiformis seemed to enhance the bioadvective solute transport, although an increased supply of oxygen was due to the highly reducing conditions of the sediment mainly seen as secondary effects related to porewater distributions and benthic nutrient fluxes.

Diffraction of a shock wave by a compression corner; regular and single Mach reflection

NASA Technical Reports Server (NTRS)

Vijayashankar, V. S.; Kutler, P.; Anderson, D.

1976-01-01

The two dimensional, time dependent Euler equations which govern the flow field resulting from the injection of a planar shock with a compression corner are solved with initial conditions that result in either regular reflection or single Mach reflection of the incident planar shock. The Euler equations which are hyperbolic are transformed to include the self similarity of the problem. A normalization procedure is employed to align the reflected shock and the Mach stem as computational boundaries to implement the shock fitting procedure. A special floating fitting scheme is developed in conjunction with the method of characteristics to fit the slip surface. The reflected shock, the Mach stem, and the slip surface are all treated as harp discontinuities, thus, resulting in a more accurate description of the inviscid flow field. The resulting numerical solutions are compared with available experimental data and existing first-order, shock-capturing numerical solutions.

Why does Kevlar decompose, while Nomex does not, when treated with aqueous chlorine solutions?

PubMed

Akdag, Akin; Kocer, Hasan B; Worley, S D; Broughton, R M; Webb, T R; Bray, Travis H

2007-05-24

Kevlar and Nomex are high-performance polymers which have wide varieties of applications in daily life. Recently, they have been proposed to be biocidal materials when reacted with household bleach (sodium hypochlorite solution) because they contain amide moieties which can be chlorinated to generate biocidal N-halamine functional groups. Although Nomex can be chlorinated without any significant decomposition, Kevlar decomposes under the same chlorination conditions. In this study, two mimics for each of the polymers were synthesized to simulate the carboxylate and diaminophenylene components of the materials. It was found that the p-diaminophenylene component of the Kevlar mimic is oxidized to a quinone-type structure upon treatment with hypochlorous acid, which then decomposes. However, such a mechanism for the Nomex mimic is not possible. In this paper, based upon these observations, a plausible answer will be provided to the title question.

Biosorption of cadmium (II) from aqueous solutions by natural and modified non-living leaves of Posidonia oceanica.

PubMed

Meseguer, Víctor F; Ortuño, Juan F; Aguilar, M Isabel; Pinzón-Bedoya, Martha L; Lloréns, Mercedes; Sáez, José; Pérez-Marín, Ana B

2016-12-01

Natural, HCl-treated, and formaldehyde-treated non-living leaves of Posidonia oceanica, a marine plant, were investigated as potential biosorbents to remove Cd 2+ from aqueous solutions. The studied biosorbents were characterized by elemental analysis and Fourier transform infrared spectroscopy (FTIR) and it was observed that the adsorption capacity of the biosorbents strongly depended on the pH, increasing as the pH rises. The adsorption process was fast. The adsorption kinetic was analyzed using five kinetic models: pseudo-first order, pseudo-second order, Elovich, intraparticle diffusion, and Bangham models. The adsorption isotherms were analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich, Sips, Redlich-Peterson, and Toth models. The maximum biosorption capacity was attained by the biosorbent treated with HCl (1.11 mmol g -1 ). The distribution equilibrium constant and the Gibbs free energy change were calculated. The effects of the presence of Na + , K + , Mg 2+ , and Ca 2+ ions in the solution on Cd 2+ uptake were studied. Results indicate that non-living leaves of P. oceanica, natural or treated, can be considered as effective and low-cost biosorbents for the removal of cadmium from aqueous solutions.

Flame atomic absorption spectrometric determination of heavy metals in aqueous solution and surface water preceded by co-precipitation procedure with copper(II) 8-hydroxyquinoline

NASA Astrophysics Data System (ADS)

Ipeaiyeda, Ayodele Rotimi; Ayoade, Abisayo Ruth

2017-12-01

Co-precipitation procedure has widely been employed for preconcentration and separation of metal ions from the matrices of environmental samples. This is simply due to its simplicity, low consumption of separating solvent and short duration for analysis. Various organic ligands have been used for this purpose. However, there is dearth of information on the application of 8-hydroxyquinoline (8-HQ) as ligand and Cu(II) as carrier element. The use of Cu(II) is desirable because there is no contamination and background adsorption interference. Therefore, the objective of this study was to use 8-HQ in the presence of Cu(II) for coprecipitation of Cd(II), Co(II), Cr(III), Ni(II) and Pb(II) from standard solutions and surface water prior to their determinations by flame atomic absorption spectrometry (FAAS). The effects of pH, sample volume, amount of 8-HQ and Cu(II) and interfering ions on the recoveries of metal ions from standard solutions were monitored using FAAS. The water samples were treated with 8-HQ under the optimum experimental conditions and metal concentrations were determined by FAAS. The metal concentrations in water samples not treated with 8-HQ were also determined. The optimum recovery values for metal ions were higher than 85.0%. The concentrations (mg/L) of Co(II), Ni(II), Cr(III), and Pb(II) in water samples treated with 8-HQ were 0.014 ± 0.002, 0.03 ± 0.01, 0.04 ± 0.02 and 0.05 ± 0.02, respectively. These concentrations and those obtained without coprecipitation technique were significantly different. Coprecipitation procedure using 8-HQ as ligand and Cu(II) as carrier element enhanced the preconcentration and separation of metal ions from the matrix of water sample.

Study of coherent synchrotron radiation effects by means of a new simulation code based on the non-linear extension of the operator splitting method

NASA Astrophysics Data System (ADS)

Dattoli, G.; Migliorati, M.; Schiavi, A.

2007-05-01

The coherent synchrotron radiation (CSR) is one of the main problems limiting the performance of high-intensity electron accelerators. The complexity of the physical mechanisms underlying the onset of instabilities due to CSR demands for accurate descriptions, capable of including the large number of features of an actual accelerating device. A code devoted to the analysis of these types of problems should be fast and reliable, conditions that are usually hardly achieved at the same time. In the past, codes based on Lie algebraic techniques have been very efficient to treat transport problems in accelerators. The extension of these methods to the non-linear case is ideally suited to treat CSR instability problems. We report on the development of a numerical code, based on the solution of the Vlasov equation, with the inclusion of non-linear contribution due to wake field effects. The proposed solution method exploits an algebraic technique that uses the exponential operators. We show that the integration procedure is capable of reproducing the onset of instability and the effects associated with bunching mechanisms leading to the growth of the instability itself. In addition, considerations on the threshold of the instability are also developed.

Experimental system to displace radioisotopes from upper to deeper soil layers: chemical research

PubMed Central

Cazzola, Pietro; Cena, Agostino; Ghignone, Stefano; Abete, Maria C; Andruetto, Sergio

2004-01-01

Background Radioisotopes are introduced into the environment following nuclear power plant accidents or nuclear weapons tests. The immobility of these radioactive elements in uppermost soil layers represents a problem for human health, since they can easily be incorporated in the food chain. Preventing their assimilation by plants may be a first step towards the total recovery of contaminated areas. Methods The possibility of displacing radionuclides from the most superficial soil layers and their subsequent stabilisation at lower levels were investigated in laboratory trials. An experimental system reproducing the environmental conditions of contaminated areas was designed in plastic columns. A radiopolluted soil sample was treated with solutions containing ions normally used in fertilisation (NO3-, NH4+, PO4--- and K+). Results Contaminated soils treated with an acid solution of ions NO3-, PO4--- and K+, undergo a reduction of radioactivity up to 35%, after a series of washes which simulate one year's rainfall. The capacity of the deepest soil layers to immobilize the radionuclides percolated from the superficial layers was also confirmed. Conclusion The migration of radionuclides towards deeper soil layers, following chemical treatments, and their subsequent stabilization reduces bioavailability in the uppermost soil horizon, preventing at the same time their transfer into the water-bearing stratum. PMID:15132749

Roll-to-Roll Manufacturing of Robust Superhydrophobic Coating on Metallic Engineering Materials.

PubMed

Dong, Shuliang; Wang, Zhenlong; Wang, Yukui; Bai, Xuelin; Fu, Yong Qing; Guo, Bin; Tan, Chaoliang; Zhang, Jia; Hu, PingAn

2018-01-17

Creating a robust superhydrophobic surface on the conventional engineering materials at mass production is of great importance for a self-cleaning, anti-icing, nonwetting surface and low flow resistance in industrial applications. Herein, we report a roll-to-roll strategy to create durable and robust superhydrophobic surfaces with designed micro-/nanoscale hierarchical structures on many conventional engineering materials by combining electrical discharge machining and coating of carbon nanoparticles, followed by oil penetration and drying. The treated surface shows good superhydrophobic properties with a static water contact angle of 170 ± 2° and slide angle of 3 ± 1°. The treated surface also exhibits good resilience and maintains the performance after being tested in various harsh conditions, including water flushing for several days, sand abrasion, scratching with sandpapers, and corrosive solution. Significantly, the superhydrophobic surfaces also show a high efficiency of self-cleaning properties even after oil contamination during applications.

Stress Corrosion Cracking Study of Aluminum Alloys Using Electrochemical Noise Analysis

NASA Astrophysics Data System (ADS)

Rathod, R. C.; Sapate, S. G.; Raman, R.; Rathod, W. S.

2013-12-01

Stress corrosion cracking studies of aluminum alloys AA2219, AA8090, and AA5456 in heat-treated and non heat-treated condition were carried out using electrochemical noise technique with various applied stresses. Electrochemical noise time series data (corrosion potential vs. time) was obtained for the stressed tensile specimens in 3.5% NaCl aqueous solution at room temperature (27 °C). The values of drop in corrosion potential, total corrosion potential, mean corrosion potential, and hydrogen overpotential were evaluated from corrosion potential versus time series data. The electrochemical noise time series data was further analyzed with rescaled range ( R/ S) analysis proposed by Hurst to obtain the Hurst exponent. According to the results, higher values of the Hurst exponents with increased applied stresses showed more susceptibility to stress corrosion cracking as confirmed in case of alloy AA 2219 and AA8090.

Solar photo-degradation of a pharmaceutical wastewater effluent in a semi-industrial autonomous plant.

PubMed

Expósito, Antonio J; Durán, Antonio; Monteagudo, José M; Acevedo, Alba

2016-05-01

An industrial wastewater effluent coming from a pharmaceutical laboratory has been treated in a semi-industrial autonomous solar compound parabolic collector (CPC) plant. A photo-Fenton process assisted with ferrioxalate has been used. Up to 79% of TOC can be removed in 2 h depending on initial conditions when treating an aqueous effluent containing up to 400 ppm of initial organic carbon concentration (TOC). An initial ratio of Fe(II)/TOC higher than 0.5 guarantees a high removal. It can be seen that most of TOC removal occurs early in the first hour of reaction. After this time, mineralization was very slow, although H2O2 was still present in solution. Indeed it decomposed to form oxygen in inefficient reactions. It is clear that remaining TOC was mainly due to the presence of acetates which are difficult to degrade. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of heat treatment on size, structure, and bioactivity of elemental selenium nanoparticles

PubMed Central

Zhang, Jinsong; Taylor, Ethan W; Wan, Xiaochun; Peng, Dungeng

2012-01-01

Background Elemental selenium nanoparticles have emerged as a novel selenium source with the advantage of reduced risk of selenium toxicity. The present work investigated whether heat treatment affects the size, structure, and bioactivity of selenium nanoparticles. Methods and results After a one-hour incubation of solution containing 80 nm selenium particles in a 90°C water bath, the nanoparticles aggregated into larger 110 nm particles and nanorods (290 nm × 70 nm), leading to significantly reduced bioavailability and phase II enzyme induction in selenium-deficient mice. When a solution containing 40 nm selenium nanoparticles was treated under the same conditions, the nanoparticles aggregated into larger 72 nm particles but did not transform into nanorods, demonstrating that the thermostability of selenium nanoparticles is size-dependent, smaller selenium nanoparticles being more resistant than larger selenium nanoparticles to transformation into nanorods during heat treatment. Conclusion The present results suggest that temperature and duration of the heat process, as well as the original nanoparticle size, should be carefully selected when a solution containing selenium nanoparticles is added to functional foods. PMID:22359458

The protective ability of Camellia meal extract on the silk protein

NASA Astrophysics Data System (ADS)

Weng, JZ; Cai, C.; Zhang, DY; Dai, BK

2018-02-01

With the enhancement of living standards, people pay more and more attention to the health. The edible oil become more and more popular, but also produced a large amount of Camellia meal which can not fully put into utilization. In this study, the extracting liquid of Camellia meal was used on the process of silk degumming. Firstly, tussah silk was treated by degumming in the Na2CO3 solution, and the preliminary condition of tussah silk degumming was obtained by orthogonal experiment: the concentration Na2CO3 was 0.1%, the degumming time was 1 hour, and the ratio of silk/water was 40:1. Then the extract of Camellia meal (GCJSY) was added before the bleaching process of tussah silk to investigate the protective ability of GCJSY on the silk protein basry on the residual ratio of the silk. While the concentration of GYJSY was 0.08%, the residual ratio of silk after degumming in the Na2CO3 solution and bleaching in the 2% H2O2 solution was 87.2%.

Catalytic determination of vanadium in water

USGS Publications Warehouse

Fishman, M. J.; Skougstad, M.W.

1964-01-01

A rapid, accurate, and sensitive spectrophotometric method for the quantitative determination of trace amounts of vanadium in water is based on the catalytic effect of vanadium on the rate of oxidation of gallic acid by persulfate in acid solution. Under given conditions of concentrations of reactants, temperature, and reaction time, the extent of oxidation of gallic acid is proportional to the concentration of vanadium present. Vanadium is determined by measuring the absorbance of the sample at 415 m?? and comparison with standard solutions treated in an identical manner. Concentrations in the range of from 0.1 to 8.0 ??g. per liter may be determined with a standard deviation of 0.2 or less. By reducing the reaction time, the method may be extended to cover the range from 1 to 100 ??g. with a standard deviation of 0.8 or less. Several substances interfere, including chloride above 100 p.p.m., and bromide and iodide in much lower concentrations. Interference from the halides is eliminated or minimized by the addition of mercuric nitrate solution. Most other substances do not interfere at the concentration levels at which they commonly occur in natural waters.

Solution of the Inverse Problem for Thin Film Patterning by Electrohydrodynamic Forces

NASA Astrophysics Data System (ADS)

Zhou, Chengzhe; Troian, Sandra

2017-11-01

Micro- and nanopatterning techniques for applications ranging from optoelectronics to biofluidics have multiplied in number over the past decade to include adaptations of mature technologies as well as novel lithographic techniques based on periodic spatial modulation of surface stresses. We focus here on one such technique which relies on shape changes in nanofilms responding to a patterned counter-electrode. The interaction of a patterned electric field with the polarization charges at the liquid interface causes a patterned electrostatic pressure counterbalanced by capillary pressure which leads to 3D protrusions whose shape and evolution can be terminated as needed. All studies to date, however, have investigated the evolution of the liquid film in response to a preset counter-electrode pattern. In this talk, we present solution of the inverse problem for the thin film equation governing the electrohydrodynamic response by treating the system as a transient control problem. Optimality conditions are derived and an efficient corresponding solution algorithm is presented. We demonstrate such implementation of film control to achieve periodic, free surface shapes ranging from simple circular cap arrays to more complex square and sawtooth patterns.

EFFECT OF SILICATE ON GRAM STAINING AND VIABILITY OF PNEUMOCOCCI AND OTHER BACTERIA

PubMed Central

MacLeod, Colin M.; Roe, Amy S.

1956-01-01

Application of silicate solutions to living or heat-killed pneumococci and to certain "viridans" streptococci causes their conversion from a Gram-positive to a Gram-negative state. The original staining properties can be restored by suspending the silicate-treated bacteria in alkaline solutions of various salts but not by simple washing in water. Living pneumococci and the strains of streptococci whose staining properties are similarly affected are killed when suspended in silicate solutions. In other Gram-positive species silicate causes conversion to Gram negativity but restoration to positivity occurs upon washing in water. In a third group of Gram-positive organisms silicate has no effect on the Gram reaction. The viability of organisms in these two groups is unaffected by silicate under the conditions employed. No effect on staining or viability of Gram-negative bacteria has been observed. The effects of silicate on staining and viability are inhibited by nutrient broth or whole serum but not by purified serum albumin. Lecithin, choline, and other substituted ammonium compounds also inhibit the effects of silicate on pneumococci. PMID:13306854

Cost-effectiveness landscape analysis of treatments addressing xerostomia in patients receiving head and neck radiation therapy

PubMed Central

Sasportas, Laura S.; Hosford, Andrew T.; Sodini, Maria A.; Waters, Dale J.; Zambricki, Elizabeth A.; Barral, Joëlle K.; Graves, Edward E.; Brinton, Todd J.; Yock, Paul G.; Le, Quynh-Thu; Sirjani, Davud

2014-01-01

Head and neck (H&N) radiation therapy (RT) can induce irreversible damage to the salivary glands thereby causing long-term xerostomia or dry mouth in 68%–85% of the patients. Not only does xerostomia significantly impair patients’ quality-of-life (QOL) but it also has important medical sequelae, incurring high medical and dental costs. In this article, we review various measures to assess xerostomia and evaluate current and emerging solutions to address this condition in H&N cancer patients. These solutions typically seek to accomplish 1 of the 4 objectives: (1) to protect the salivary glands during RT, (2) to stimulate the remaining gland function, (3) to treat the symptoms of xerostomia, or (4) to regenerate the salivary glands. For each treatment, we assess its mechanisms of action, efficacy, safety, clinical utilization, and cost. We conclude that intensity-modulated radiation therapy is both the most widely used prevention approach and the most cost-effective existing solution and we highlight novel and promising techniques on the cost-effectiveness landscape. PMID:23643579

Analytical approximations to the dynamics of an array of coupled DC SQUIDs

NASA Astrophysics Data System (ADS)

Berggren, Susan; Palacios, Antonio

2014-04-01

Coupled dynamical systems that operate near the onset of a bifurcation can lead, under certain conditions, to strong signal amplification effects. Over the past years we have studied this generic feature on a wide range of systems, including: magnetic and electric fields sensors, gyroscopic devices, and arrays of loops of superconducting quantum interference devices, also known as SQUIDs. In this work, we consider an array of SQUID loops connected in series as a case study to derive asymptotic analytical approximations to the exact solutions through perturbation analysis. Two approaches are considered. First, a straightforward expansion in which the non-linear parameter related to the inductance of the DC SQUID is treated as the small perturbation parameter. Second, a more accurate procedure that considers the SQUID phase dynamics as non-uniform motion on a circle. This second procedure is readily extended to the series array and it could serve as a mathematical framework to find approximate solutions to related complex systems with high-dimensionality. To the best of our knowledge, an approximate analytical solutions to an array of SQUIDs has not been reported yet in the literature.

Nuclear magnetic resonance signal dynamics of liquids in the presence of distant dipolar fields, revisited

PubMed Central

Barros, Wilson; Gochberg, Daniel F.; Gore, John C.

2009-01-01

The description of the nuclear magnetic resonance magnetization dynamics in the presence of long-range dipolar interactions, which is based upon approximate solutions of Bloch–Torrey equations including the effect of a distant dipolar field, has been revisited. New experiments show that approximate analytic solutions have a broader regime of validity as well as dependencies on pulse-sequence parameters that seem to have been overlooked. In order to explain these experimental results, we developed a new method consisting of calculating the magnetization via an iterative formalism where both diffusion and distant dipolar field contributions are treated as integral operators incorporated into the Bloch–Torrey equations. The solution can be organized as a perturbative series, whereby access to higher order terms allows one to set better boundaries on validity regimes for analytic first-order approximations. Finally, the method legitimizes the use of simple analytic first-order approximations under less demanding experimental conditions, it predicts new pulse-sequence parameter dependencies for the range of validity, and clarifies weak points in previous calculations. PMID:19425789

Space-time domain solutions of the wave equation by a non-singular boundary integral method and Fourier transform.

PubMed

Klaseboer, Evert; Sepehrirahnama, Shahrokh; Chan, Derek Y C

2017-08-01

The general space-time evolution of the scattering of an incident acoustic plane wave pulse by an arbitrary configuration of targets is treated by employing a recently developed non-singular boundary integral method to solve the Helmholtz equation in the frequency domain from which the space-time solution of the wave equation is obtained using the fast Fourier transform. The non-singular boundary integral solution can enforce the radiation boundary condition at infinity exactly and can account for multiple scattering effects at all spacings between scatterers without adverse effects on the numerical precision. More generally, the absence of singular kernels in the non-singular integral equation confers high numerical stability and precision for smaller numbers of degrees of freedom. The use of fast Fourier transform to obtain the time dependence is not constrained to discrete time steps and is particularly efficient for studying the response to different incident pulses by the same configuration of scatterers. The precision that can be attained using a smaller number of Fourier components is also quantified.

PREPARATION OF HIGH PURITY UF$sub 4$

DOEpatents

Magner, J.E.; Long, R.S.; Ellis, D.A.; Grinstead, R.R.

1962-04-17

S>A process for preparing very highly pure uranous tetrafluoride from impure uranium laden solvent extraction strip solutions, ion exchange process and resin-inpulp process eluate solutions which are at least 8M in hydrochloric acid is described. The process first comprises treating any of the above-mentioned solutions with a reducing agent to reduce the uranium to the + 4 oxidation state, and then contacting the reduced solution with an extractant phase comprising about 10 to 70% of tri-butyl phosphate in an organic solvent-diluent selected from benzene, ethyl-benzene, chlorobenzene, xylene, kerosene, or the like. The uranium is extracted into the extractant phase and is subsequently precipitated by treating the extractant with an aqueous fluoride solution. The highly pure uranous tetrafluoride precipitate is separated from the phases and recovered for subsequent utilization. (AEC)

Method for treating liquid wastes

DOEpatents

Katti, K.V.; Volkert, W.A.; Singh, P.; Ketring, A.R.

1995-12-26

The method of treating liquid waste in a media is accomplished by exposing the media to phosphinimines and sequestering {sup 99}Tc from the media by the phosphinimine (PN) functionalities. The system for treating the liquid waste in the media includes extraction of {sup 99}TcO{sub 4}{sup {minus}} from aqueous solutions into organic solvents or mixed organic/polar media, extraction of {sup 99}Tc from solutions on a solid matrix by using a container containing PN functionalities on solid matrices including an inlet and outlet for allowing flow of media through an immobilized phosphinimine ligand system contained within the container. Also, insoluble suspensions of phosphinimine functionalities on solid matrices in liquid solutions or present on supported liquid membranes (SLM) can be used to sequester {sup 99}Tc from those liquids. 6 figs.

Method for treating liquid wastes

DOEpatents

Katti, Kattesh V.; Volkert, Wynn A.; Singh, Prahlad; Ketring, Alan R.

1995-01-01

The method of treating liquid waste in a media is accomplished by exposing the media to phosphinimines and sequestering .sup.99 Tc from the media by the phosphinimine (PN) functionalities. The system for treating the liquid waste in the media includes extraction of .sup.99 TcO.sub.4.sup.- from aqueous solutions into organic solvents or mixed organic/polar media, extraction of .sup.99 Tc from solutions on a solid matrix by using a container containing PN functionalities on solid matrices including an inlet and outlet for allowing flow of media through an immobilized phosphinimine ligand system contained within the container. Also, insoluble suspensions of phosphinimine functionalities on solid matrices in liquid solutions or present on supported liquid membranes (SLM) can be used to sequester .sup.99 Tc from those liquids.

Algebraic Construction of Exact Difference Equations from Symmetry of Equations

NASA Astrophysics Data System (ADS)

Itoh, Toshiaki

2009-09-01

Difference equations or exact numerical integrations, which have general solutions, are treated algebraically. Eliminating the symmetries of the equation, we can construct difference equations (DCE) or numerical integrations equivalent to some ODEs or PDEs that means both have the same solution functions. When arbitrary functions are given, whether we can construct numerical integrations that have solution functions equal to given function or not are treated in this work. Nowadays, Lie's symmetries solver for ODE and PDE has been implemented in many symbolic software. Using this solver we can construct algebraic DCEs or numerical integrations which are correspond to some ODEs or PDEs. In this work, we treated exact correspondence between ODE or PDE and DCE or numerical integration with Gröbner base and Janet base from the view of Lie's symmetries.

Potentiodynamic polarization study of the in vitro corrosion behavior of 3 high-palladium alloys and a gold-palladium alloy in 5 media.

PubMed

Sun, Desheng; Monaghan, Peter; Brantley, William A; Johnston, William M

2002-01-01

Corrosion of cast alloy restorations may lead to their failure or adversely affect their biocompatibility. Although some documentation of the corrosion behavior of the high-palladium dental alloys exists, questions remain about their corrosion resistance and mechanisms. This study compared the in vitro corrosion characteristics of 3 high-palladium alloys and 1 gold-palladium alloy in simulated body fluid and oral environments. Two Pd-Cu-Ga alloys and 1 Pd-Ga alloy were selected; an Au-Pd alloy served as the control. The corrosion behavior for the as-cast and simulated porcelain-firing (heat-treated) conditions of each alloy (N = 5) was evaluated in 0.9% NaCl, 0.09% NaCl, and Fusayama solutions. Heat-treated specimens of each alloy (N = 5) were also tested in N(2)-deaerated 0.09% NaCl and Fusayama solutions (pH 4). After immersion in the electrolyte for 24 hours, the open-circuit potential (OCP) was measured, and linear polarization was performed from -20 mV to +20 mV (vs. OCP) at a scanning rate of 0.125 mV/s. Cyclic polarization was performed from -300 mV to +1000 mV and back to -300 mV (vs. OCP) at a scanning rate of 1 mV/s. Data were evaluated with analysis of variance and the Ryan-Einot-Gabriel-Welsch multiple-range test (alpha=.05). The OCP of each alloy varied with the condition (as-cast or heat-treated) and electrolyte used. Corrosion resistance was similar for the 4 alloys tested. For cyclic polarization, all alloys showed active-passive or spontaneous passive behavior in nearly all electrolytes. During some reverse scans, the 3 high-palladium alloys displayed 3 or 5 anodic peaks. No positive hysteresis was observed for any of the alloy/electrolyte combinations evaluated. The corrosion resistances of the 3 high-palladium alloys in simulated body fluid and oral environments were comparable to that of the gold-palladium alloy. The similar corrosion resistance for the 3 high-palladium alloys was attributed to their high noble metal content and theorized stable structure at the submicron level. Selective corrosion of different phases and elements, surface enrichment of palladium, and adsorption of species are possible corrosion mechanisms. The cyclic polarization results suggest that none of the 4 alloys would be prone to pitting or crevice corrosion under in vivo conditions, but crevice conditions should nonetheless be avoided for these alloys in the oral environment.

Factors accounting for the rise in health-care spending in the United States: the role of rising disease prevalence and treatment intensity.

PubMed

Thorpe, Kenneth E

2006-11-01

To examine the factors responsible for the rise in health- care spending in the United States over the past 15 years. Nationally representative survey data from 1987 and 2003 were used to examine the top medical conditions accounting for the rise in spending. I also estimate how much of the rise is traced to rising treated disease prevalence and rising spending per case. The study finds most of the rise in spending is linked to rising rates of treated disease prevalence. The rise in prevalence is associated with the doubling of obesity in the US and changes in clinical thresholds for treating asymptomatic patients with certain cardiovascular risk factors. Most of the policy solutions offered in the US to slow the growth in spending do not address the fundamental factors accounting for spending growth. More aggressive efforts for slowing the growth in obesity among adults and children should be centre-stage in the efforts to slow the rise in health-care spending.

Synthesis and Performance Evaluation of a New Deoiling Agent for Treatment of Waste Oil-Based Drilling Fluids

PubMed Central

Liu, Pingting; Huang, Zhiyu; Deng, Hao; Wang, Rongsha; Xie, Shuixiang

2014-01-01

Oil-based drilling fluid is used more and more in the field of oil and gas exploration. However, because of unrecyclable treating agent and hard treatment conditions, the traditional treating technologies of waste oil-based drilling fluid have some defects, such as waste of resource, bulky equipment, complex treatment processes, and low oil recovery rate. In this work, switchable deoiling agent (SDA), as a novel surfactant for treatment of waste oil-based drilling fluid, was synthesized by amine, formic acid, and formaldehyde solution. With this agent, the waste oil-based drilling fluid can be treated without complex process and expensive equipment. Furthermore, the agent used in the treatment can be recycled, which reduces waste of resource and energy. The switch performance, deoiling performance, structural characterization, and mechanisms of action are studied. The experimental results show that the oil content of the recycled oil is higher than 96% and more than 93% oil in waste oil-based drilling fluid can be recycled. The oil content of the solid residues of deoiling is less than 3%. PMID:25045749

A case of severe chlorite poisoning successfully treated with early administration of methylene blue, renal replacement therapy, and red blood cell transfusion: case report.

PubMed

Gebhardtova, Andrea; Vavrinec, Peter; Vavrincova-Yaghi, Diana; Seelen, Mark; Dobisova, Anna; Flassikova, Zora; Cikova, Andrea; Henning, Robert H; Yaghi, Aktham

2014-08-01

The case of a 55-year-old man who attempted suicide by ingesting <100 mL of 28% sodium chlorite solution is presented. On arrival in the intensive care unit, the patient appeared cyanotic with lowered consciousness and displayed anuria and chocolate brown serum.Initial laboratory tests revealed 40% of methemoglobin. The formation of methemoglobin was effectively treated with methylene blue (10% after 29 hours).To remove the toxin, and because of the anuric acute renal failure, the patient received renal replacement therapy. Despite these therapeutic measures, the patient developed hemolytic anemia and disseminated intravascular coagulation, which were treated with red blood cell transfusion and intermittent hemodialysis. These interventions led to the improvement of his condition and the patient eventually fully recovered. Patient gave written informed consent.This is the third known case of chlorite poisoning that has been reported. Based upon this case, we suggest the management of sodium chlorite poisoning to comprise the early administration of methylene blue, in addition to renal replacement therapy and transfusion of red blood cells.

A Case of Severe Chlorite Poisoning Successfully Treated With Early Administration of Methylene Blue, Renal Replacement Therapy, and Red Blood Cell Transfusion

PubMed Central

Gebhardtova, Andrea; Vavrinec, Peter; Vavrincova-Yaghi, Diana; Seelen, Mark; Dobisova, Anna; Flassikova, Zora; Cikova, Andrea; Henning, Robert H.; Yaghi, Aktham

2014-01-01

Abstract The case of a 55-year-old man who attempted suicide by ingesting <100 mL of 28% sodium chlorite solution is presented. On arrival in the intensive care unit, the patient appeared cyanotic with lowered consciousness and displayed anuria and chocolate brown serum. Initial laboratory tests revealed 40% of methemoglobin. The formation of methemoglobin was effectively treated with methylene blue (10% after 29 hours). To remove the toxin, and because of the anuric acute renal failure, the patient received renal replacement therapy. Despite these therapeutic measures, the patient developed hemolytic anemia and disseminated intravascular coagulation, which were treated with red blood cell transfusion and intermittent hemodialysis. These interventions led to the improvement of his condition and the patient eventually fully recovered. Patient gave written informed consent. This is the third known case of chlorite poisoning that has been reported. Based upon this case, we suggest the management of sodium chlorite poisoning to comprise the early administration of methylene blue, in addition to renal replacement therapy and transfusion of red blood cells. PMID:25144325

Synthesis and performance evaluation of a new deoiling agent for treatment of waste oil-based drilling fluids.

PubMed

Liu, Pingting; Huang, Zhiyu; Deng, Hao; Wang, Rongsha; Xie, Shuixiang

2014-01-01

Oil-based drilling fluid is used more and more in the field of oil and gas exploration. However, because of unrecyclable treating agent and hard treatment conditions, the traditional treating technologies of waste oil-based drilling fluid have some defects, such as waste of resource, bulky equipment, complex treatment processes, and low oil recovery rate. In this work, switchable deoiling agent (SDA), as a novel surfactant for treatment of waste oil-based drilling fluid, was synthesized by amine, formic acid, and formaldehyde solution. With this agent, the waste oil-based drilling fluid can be treated without complex process and expensive equipment. Furthermore, the agent used in the treatment can be recycled, which reduces waste of resource and energy. The switch performance, deoiling performance, structural characterization, and mechanisms of action are studied. The experimental results show that the oil content of the recycled oil is higher than 96% and more than 93% oil in waste oil-based drilling fluid can be recycled. The oil content of the solid residues of deoiling is less than 3%.

Effect of PWHT on Microstructure, Mechanical and Corrosion Behaviour of Gas Tungsten Arc Welds of IN718 Superalloys

NASA Astrophysics Data System (ADS)

Dilkush; Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

2018-03-01

The present work aims to improve corrosion resistance and mechanical behavior of the welds with suitable post weld heat treatment i.e. direct aging and solutionizing treatments (980STA, 1080STA). Gas tungsten arc welding (GTAW) has been performed on Inconel 718 (IN718) nickel based super alloy plates with 3mm thickness. The structural –property relationship of the post weld heat treated samples is judged by correlating the microstructural changes with observed mechanical behavior and pitting corrosion resistance of the welds As-recevied, direct aging (DA), 980STA,1080STA were studied. Welds were characterized for microstructure changes with scanning electron microscopy (SEM) and optical microscopy (OM).Vickers micro- hardness tester was used to measure the hardness of the weldments. Potential-dynamic polarization testing was carried out to study the pitting corrosion resistance in 3.5%NaCl (Sodium chloride) solution at 30°C.Results of the present study established that post weld heat treatments resulted in promoting the element segregation diffusion and resolve them from brittle laves particles in the matrix. Increased precipitation of strengthening phases lead to a significant increase in fusion zone hardness of 1080STA post weld heat treated condition compared to as welded, direct aged, 980STA conditions. Due to significant changes in the microstructural behavior of 1080STA condition resulted in superior pitting corrosion resistance than 980STA, direct aged and as- recevied conditions of IN718 GTA welds

Kinetic model of the thermal pyrolysis of chrome tanned leather treated with NaOH under different conditions using thermogravimetric analysis.

PubMed

Bañón, E; Marcilla, A; García, A N; Martínez, P; León, M

2016-02-01

The thermal decomposition of chrome tanned leather before and after a soaking treatment with NaOH was studied using thermogravimetric analysis (TGA). The effect of the solution concentration (0.2M and 0.5M) and the soaking time (5min and 15min) was evaluated. TGA experiments at four heating rates (5, 10, 15 and 20°Cmin(-1)) were run in a nitrogen atmosphere for every treatment condition. A kinetic model was developed considering the effect of the three variables studied, i.e.: the NaOH solution concentration, the soaking time and the heating rate. The proposed model for chrome tanned leather pyrolysis involves a set of four reactions, i.e.: three independent nth order reactions, yielding the corresponding products and one of them undergoing a successive cero order reaction. The model was successfully applied simultaneously to all the experimental data obtained. The evaluation of the kinetic parameters obtained (activation energy, pre-exponential factor and reaction order) allowed a better understanding of the effect of the alkali treatment on these wastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Foliar sorption of emerging and priority contaminants under controlled conditions.

PubMed

Calderón-Preciado, Diana; Matamoros, Víctor; Biel, Carmen; Save, Robert; Bayona, Josep M

2013-09-15

Agricultural irrigation water contains a variety of contaminants that can be introduced into the food chain through intake by irrigated crops. This paper describes an experiment under controlled conditions designed to simulate sprinkle irrigation with polluted water at two different relative humidities (40 and 90%). Specifically, shed lettuce-heart leaves were spiked with an aqueous solution containing organic microcontaminants, including pharmaceuticals (ibuprofen, diclofenac, clofibric acid, and carbamazepine), fragrances (tonalide), biocides (triclosan), insecticides (lindane), herbicides (atrazine), phenolic estrogen (bisphenol A), and polycyclic aromatic hydrocarbons (phenanthrene and pyrene). Following an incubation period (48 h), the treated leaves were rinsed with water, and both the solution used to rinse them and the leaves themselves were independently analyzed to investigate the foliar sorption and uptake of the spiked organic contaminants through cuticle. The results showed that the foliar sorption of emerging and priority microcontaminants in leaves wetted by irrigation practices is related to their polarity (logD(ow)) and volatility (logk(H)), regardless of their compound class and the relative humidity. The results thus underscore the need to improve the quality of reclaimed water in crop irrigation, particularly when sprinkle irrigation is used. Copyright © 2013 Elsevier B.V. All rights reserved.

An approximate block Newton method for coupled iterations of nonlinear solvers: Theory and conjugate heat transfer applications

NASA Astrophysics Data System (ADS)

Yeckel, Andrew; Lun, Lisa; Derby, Jeffrey J.

2009-12-01

A new, approximate block Newton (ABN) method is derived and tested for the coupled solution of nonlinear models, each of which is treated as a modular, black box. Such an approach is motivated by a desire to maintain software flexibility without sacrificing solution efficiency or robustness. Though block Newton methods of similar type have been proposed and studied, we present a unique derivation and use it to sort out some of the more confusing points in the literature. In particular, we show that our ABN method behaves like a Newton iteration preconditioned by an inexact Newton solver derived from subproblem Jacobians. The method is demonstrated on several conjugate heat transfer problems modeled after melt crystal growth processes. These problems are represented by partitioned spatial regions, each modeled by independent heat transfer codes and linked by temperature and flux matching conditions at the boundaries common to the partitions. Whereas a typical block Gauss-Seidel iteration fails about half the time for the model problem, quadratic convergence is achieved by the ABN method under all conditions studied here. Additional performance advantages over existing methods are demonstrated and discussed.

Generalization of the Hartree-Fock approach to collision processes

NASA Astrophysics Data System (ADS)

Hahn, Yukap

1997-06-01

The conventional Hartree and Hartree-Fock approaches for bound states are generalized to treat atomic collision processes. All the single-particle orbitals, for both bound and scattering states, are determined simultaneously by requiring full self-consistency. This generalization is achieved by introducing two Ansäauttze: (a) the weak asymptotic boundary condition, which maintains the correct scattering energy and target orbitals with correct number of nodes, and (b) square integrable amputated scattering functions to generate self-consistent field (SCF) potentials for the target orbitals. The exact initial target and final-state asymptotic wave functions are not required and thus need not be specified a priori, as they are determined simultaneously by the SCF iterations. To check the asymptotic behavior of the solution, the theory is applied to elastic electron-hydrogen scattering at low energies. The solution is found to be stable and the weak asymptotic condition is sufficient to produce the correct scattering amplitudes. The SCF potential for the target orbital shows the strong penetration by the projectile electron during the collision, but the exchange term tends to restore the original form. Potential applicabilities of this extension are discussed, including the treatment of ionization and shake-off processes.

A numerical approach to finding general stationary vacuum black holes

NASA Astrophysics Data System (ADS)

Adam, Alexander; Kitchen, Sam; Wiseman, Toby

2012-08-01

The Harmonic Einstein equation is the vacuum Einstein equation supplemented by a gauge fixing term which we take to be that of DeTurck. For static black holes analytically continued to Riemannian manifolds without boundary at the horizon, this equation has previously been shown to be elliptic, and Ricci flow and Newton’s method provide good numerical algorithms to solve it. Here we extend these techniques to the arbitrary cohomogeneity stationary case which must be treated in Lorentzian signature. For stationary spacetimes with globally timelike Killing vector the Harmonic Einstein equation is elliptic. In the presence of horizons and ergo-regions it is less obviously so. Motivated by the Rigidity theorem we study a class of stationary black hole spacetimes which is general enough to include many interesting higher dimensional solutions. We argue the Harmonic Einstein equation consistently truncates to this class of spacetimes giving an elliptic problem. The Killing horizons and axes of rotational symmetry are boundaries for this problem and we determine boundary conditions there. As a simple example we numerically construct 4D rotating black holes in a cavity using Anderson’s boundary conditions. We demonstrate both Newton’s method and Ricci flow to find these Lorentzian solutions.

Cost-effective treatment solutions for rural areas: design and operation of a new package treatment plant for single households.

PubMed

Daude, D; Stephenson, T

2003-01-01

The design approach and operation of a newly developed package plant treating domestic sewage from single households were evaluated. Combining submerged aerated filter (SAF) technology with jet aeration and incorporating both into a compact and shallow tank resulted in a cost-effective treatment solution. A trial unit was permanently installed at a rural site, serving a single household. Jet aeration proved to be the best aeration method for the shallow bioreactor design. Further trials revealed a 50% reduction in suspended solids (SS) through the use of a static effluent filter and found that annual plant maintenance was vital to sustain stable operating conditions. Despite high variations in influent conditions, the trial unit produced good effluent quality during steady-state operation. Average effluent BOD5, COD and SS values were 19.6 mg l(-1), 98 mg l(-1) and 32 mg l(-1) achieving overall removal efficiencies of 94.2%, 85.9% and 87.6% respectively. However, effluent ammonia nitrogen (NH4-N) levels were found to be inconsistent varying from 9 mg l(-1) to over 60 mg l(-1).

Electrooxidation as the anaerobic pre-treatment of fats: oleate conversion using RuO2 and IrO2 based anodes.

PubMed

Gonçalves, M; Alves, M M; Correia, J P; Marques, I P

2008-11-01

Electrochemical treatment of oleate using RuO2 and IrO2 type dimensionally stable anodes in alkaline medium was performed to develop a feasible anaerobic pre-treatment of fatty effluents. The results showed that the pre-treated solutions over RuO2 were faster degraded by anaerobic consortium than the raw oleate solutions or the electrolysed solutions using IrO2. In batch experiments carried out with pre-treated solutions over RuO2 (100-500mg/L), no lag phases were observed before the methane production onset. On the other hand, raw oleate and pre-treated oleate over IrO2 had originated lag phases of 0-140 and 0-210h, respectively. This study demonstrated that it is advantageous to apply the electrochemical treatment carried out on the RuO2 type DSA in order to achieve a faster biodegradation of lipid-containing effluent and consequently to obtain a faster methane production.

Preparation of porous yttrium oxide microparticles by gelation of ammonium alginate in aqueous solution containing yttrium ions.

PubMed

Kawashita, Masakazu; Matsui, Naoko; Li, Zhixia; Miyazaki, Toshiki

2010-06-01

Porous Y2O3 microparticles 500 microm in size were obtained, when 1 wt%-ammonium alginate aqueous solution was dropped into 0.5 M-YCl3 aqueous solution by a Pasteur pipette and the resultant gel microparticles were heat-treated at 1100 degrees C. Small pores less than 1 microm were formed in the microparticles by the heat treatment. The bulk density of the heat-treated microparticle was as low as 0.66 g cm(-3). The chemical durability of the heat-treated microparticles in simulated body fluid at pH = 6 and 7 was high enough for clinical application of in situ radiotherapy. Although the size of the microparticles should be decreased to around 25 microm using atomizing device such as spray gun for clinical application, we found that the porous Y2O3 microparticles with high chemical durability and low density can be obtained by utilizing gelation of ammonium alginate in YCl3 aqueous solution in this study.

Spectral enhancement of leucocrystal violet treated footwear impression evidence in blood.

PubMed

Spence, Lindsay; Asmussen, Gary

2003-03-27

The results presented demonstrate the capacity for spectral enhancement to substantially improve the forensic examination of footwear impressions in blood treated with leucocrystal violet (LCV). The UV-Vis absorption spectra were generated of (i) an aqueous solution of leucocrystal violet, (ii) leucocrystal violet in 3% H(2)O(2), (iii) LCV working solution and (iv) whole blood added to LCV working solution. The resultant fluorescence emission spectra were subsequently generated (lambda(ex)=630nm, lambda(em)=661-900nm). The results indicate that the UV-Vis absorption spectra of an unbuffered solution of whole blood with LCV working solution produces a strong absorbance curve with a maxima at 630nm. Subsequent excitation at this wavelength and generation of the emission spectrum in the fluorescence mode indicates that a solution of whole blood added to LCV working solution is an extremely weak fluorophore. Therefore, to enable an adequate and timely enhancement of blood impression evidence treated with LCV utilising either visible fluorescence or infrared luminescence requires (i) selection of the most appropriate excitation wavelength (lambda(ex)) and emission wavelength (lambda(em)) with extremely narrow band pass filters, which in the absence of substrate matrix interference is excitation at 630nm producing the emission maxima at 665nm and (ii) a visual enhancement system such as a CCD colour IR video camera with image integration.

[Study on conditions of seed germination of Cistanche].

PubMed

Qiao, Xue-Yi; Wang, Hua-Lei; Guo, Yu-Hai

2007-09-01

To study the effect of fluridone concentration, stimulating period, temperature and salt on the seed germination of three species of Cistanche. The seeds were cultured in Petri dish, and the germination percentage was counted. The highest germination percentage was observed in Cistanche tubulosa, C. deserticola, C. sala seeds pre-treated by 0.1 mg x L(-1) fluridone for 24-29 h. The optimal temperature for the seeds germination of three species of Cistanche was at 20-30 degrees C, and the seeds did not germinate at sub-or supraoptimal temperatures (5 and 35 degrees C). The salt tolerance of C. sala seeds was strong, and the critical value of NaCl concentration was 0.04 mol x L(-1). By contrast, C. tubulosa and C. deserticola seeds were more sensitive to the salt stress, the critical value of NaCl concentration was 0.02 mol x L(-1). The optimal germination condition and the method of testing germination percentage of three species of Cistanche seeds are as follow: the seeds are pre-treated by 0.1 mg x L(-1) fluridone for 24 h and then cultured at 20-30 degrees C in salt solution which concentration is lower than 0.02 mol x L(-1).

Effects of Gold Salt Speciation and Structure of Human and Bovine Serum Albumins on the Synthesis and Stability of Gold Nanostructures

PubMed Central

Miranda, Érica G. A.; Tofanello, Aryane; Brito, Adrianne M. M.; Lopes, David M.; Albuquerque, Lindomar J. C.; de Castro, Carlos E.; Costa, Fanny N.; Giacomelli, Fernando C.; Ferreira, Fabio F.; Araújo-Chaves, Juliana C.; Nantes, Iseli L.

2016-01-01

The present study aimed to investigate the influence of albumin structure and gold speciation on the synthesis of gold nanoparticles (GNPs). The strategy of synthesis was the addition of HAuCl4 solutions at different pH values (3–12) to solutions of human and bovine serum albumins (HSA and BSA) at the same corresponding pH values. Different pH values influence the GNP synthesis due to gold speciation. Besides the inherent effect of pH on the native structure of albumins, the use N-ethylmaleimide (NEM)-treated and heat-denaturated forms of HSA and BSA provided additional insights about the influence of protein structure, net charge, and thiol group approachability on the GNP synthesis. NEM treatment, heating, and the extreme values of pH promoted loss of the native albumin structure. The formation of GNPs indicated by the appearance of surface plasmon resonance (SPR) bands became detectable from 15 days of the synthesis processes that were carried out with native, NEM-treated and heat-denaturated forms of HSA and BSA, exclusively at pH 6 and 7. After 2 months of incubation, SPR band was also detected for all synthesis carried out at pH 8.0. The mean values of the hydrodynamic radius (RH) were 24 and 34 nm for GNPs synthesized with native HSA and BSA, respectively. X-ray diffraction (XRD) revealed crystallites of 13 nm. RH, XRD, and zeta potential values were consistent with GNP capping by the albumins. However, the GNPs produced with NEM-treated and heat-denaturated albumins exhibited loss of protein capping by lowering the ionic strength. This result suggests a significant contribution of non-electrostatic interactions of albumins with the GNP surface, in these conditions. The denaturation of proteins exposes hydrophobic groups to the solvent, and these groups could interact with the gold surface. In these conditions, the thiol blockage or oxidation, the latter probably favored upon heating, impaired the formation of a stable capping by thiol coordination with the gold surface. Therefore, the cysteine side chain of albumins is important for the colloidal stabilization of GNPs rather than as the reducing agent for the synthesis. Despite the presence of more reactive gold species at more acidic pH values, i.e., below 6.0, in these conditions the loss of native albumin structure impaired GNP synthesis. Alkaline pH values (9–12) combined the unfavorable conditions of denaturated protein structure with less reactive gold species. Therefore, an optimal condition for the synthesis of GNPs using serum albumins involves more reactive gold salt species combined with a reducing and negatively charged form of the protein, all favored at pH 6–7. PMID:27066476

Poisson-Nernst-Planck Equations for Simulating Biomolecular Diffusion-Reaction Processes II: Size Effects on Ionic Distributions and Diffusion-Reaction Rates

PubMed Central

Lu, Benzhuo; Zhou, Y.C.

2011-01-01

The effects of finite particle size on electrostatics, density profiles, and diffusion have been a long existing topic in the study of ionic solution. The previous size-modified Poisson-Boltzmann and Poisson-Nernst-Planck models are revisited in this article. In contrast to many previous works that can only treat particle species with a single uniform size or two sizes, we generalize the Borukhov model to obtain a size-modified Poisson-Nernst-Planck (SMPNP) model that is able to treat nonuniform particle sizes. The numerical tractability of the model is demonstrated as well. The main contributions of this study are as follows. 1), We show that an (arbitrarily) size-modified PB model is indeed implied by the SMPNP equations under certain boundary/interface conditions, and can be reproduced through numerical solutions of the SMPNP. 2), The size effects in the SMPNP effectively reduce the densities of highly concentrated counterions around the biomolecule. 3), The SMPNP is applied to the diffusion-reaction process for the first time, to our knowledge. In the case of low substrate density near the enzyme reactive site, it is observed that the rate coefficients predicted by SMPNP model are considerably larger than those by the PNP model, suggesting both ions and substrates are subject to finite size effects. 4), An accurate finite element method and a convergent Gummel iteration are developed for the numerical solution of the completely coupled nonlinear system of SMPNP equations. PMID:21575582

Determination of atrazine and simazine in water samples by high-performance liquid chromatography after preconcentration with heat-treated diatomaceous earth.

PubMed

Katsumata, Hideyuki; Kaneco, Satoshi; Suzuki, Tohru; Ohta, Kiyohisa

2006-09-08

A sensitive and selective column adsorption method is proposed for the preconcentration and determination of atrazine and simazine. Atrazine and simazine were preconcentrated on heat-treated diatomaceous earth as an adsorbent and then determined by high-performance liquid chromatography (HPLC). Several parameters on the recoveries of the analytes were investigated. The experimental results showed that it was possible to obtain quantitative analysis when the solution pH was 2 using 100 mL of validation solution containing 1.5 microg of triazines and 5 mL of ethanol as an eluent. Recoveries of atrazine and simazine were 95.7+/-4.2% and 75.0+/-1.9% with a relative standard deviation for seven determinations of 4.7% and 2.7% under optimum conditions. The maximum preconcentration factor was 100 for triazines when 500 mL of sample solution volume was used. The linear ranges of calibration curves for atrazine and simazine were 1-150 ng mL(-1) and 1-300 ng mL(-1), respectively, with correlation coefficients of 0.999 and the detection limits (3Signal-to-Noise) were 0.24 ng mL(-1) and 0.21 ng mL(-1) for atrazine and simazine. The capacity of the adsorbent was also examined and found to be 0.8 mg g(-1) and 1.3 mg g(-1) for atrazine and simazine, respectively. The proposed method was successfully applied to the determination of triazines in river water and tap water samples with high precision and accuracy.

Photodynamic therapy versus ultrasonic irrigation: interaction with endodontic microbial biofilm, an ex vivo study.

PubMed

Muhammad, Omid H; Chevalier, Marlene; Rocca, Jean-Paul; Brulat-Bouchard, Nathalie; Medioni, Etienne

2014-06-01

Photodynamic therapy was introduced as an adjuvant to conventional chemo-mechanical debridement during endodontic treatment to overcome the persistence of biofilms. The aim of this study was to evaluate the ability of photodynamic therapy (PDT) to disrupt an experimental microbial biofilm inside the root canal in a clinically applicable working time. Thirty extracted teeth were prepared and then divided in three groups. All samples were infected with an artificially formed biofilm made of Enterococcus faecalis, Streptococcus salivarius, Porphyromonas gingivalis and Prevotella intermedia bacteria. First group was treated with Aseptim Plus® photo-activated (LED) disinfection system, second group by a 650 nm Diode Laser and Toluidine blue as photosensitizer, and the third group, as control group, by ultrasonic irrigation (PUI) using EDTA 17% and NaOCl 2.6% solutions. The working time for all three groups was fixed at 3 min. Presence or absence of biofilm was assessed by aerobic and anaerobic cultures. There was no statistically significant difference between results obtained from groups treated by Aseptim Plus® and Diode Laser (P<0.6267). In cultures of both groups there was a maximal bacterial growth. The group that was treated by ultrasonic irrigation and NaOCl and EDTA solutions had the best results (P<0.0001): there was a statistically significant reduction of bacterial load and destruction of microbial biofilm. Under the condition of this study, Photodynamic therapy could not disrupt endodontic artificial microbial biofilm and could not inhibit bacterial growth in a clinically favorable working time. Copyright © 2014 Elsevier B.V. All rights reserved.

Combinatorial effects of charge characteristics and hydrophobicity of silk fibroin on the sorption and release of charged dyes.

PubMed

Wongpanit, Panya; Rujiravanit, Ratana

2012-01-01

The present study was designed to examine the influence of the charge characteristics of silk fibroin on the sorption and release of charged dyes by varying the pH values of the sorption and release media as well as types of charged dyes. Negatively charged dyes (phenol red and chromotrope 2R) and positively charged dyes (crystal violet and indoine blue) were used as the model compounds. Silk fibroin films were prepared by using a solution casting technique. The prepared films were then treated with an aqueous methanol solution or annealed with water to control their conformation. The sorption behavior of the model compounds made by the methanol-treated and water-annealed silk fibroin films was investigated. Compared to the water- annealed silk fibroin films, a higher hydrophobicity of the methanol-treated silk fibroin films caused a higher sorption of the hydrophobic dyes. The dye molecules had a fairly high affinity to the silk fibroin film, even though the dye and the matrix possessed the same charge. However, in the presence of two charged groups in a single dye molecule, the electrostatic repulsion become more dominant. Stronger interaction was observed when the charges of the film and the dye were opposite. The results of dye sorption and release experiments showed that the degree of synergism or competition between electrostatic and hydrophobic interactions directly depended on the charges and chemical structure of the dye molecules and the environmental pH conditions of the existing silk fibroin film.

Effect of basic alkali-pickling conditions on the production of lysinoalanine in preserved eggs.

PubMed

Zhao, Yan; Luo, Xuying; Li, Jianke; Xu, Mingsheng; Tu, Yonggang

2015-09-01

During the pickling process, strong alkali causes significant lysinoalanine (LAL) formation in preserved eggs, which may reduce the nutritional value of the proteins and result in a potential hazard to human health. In this study, the impacts of the alkali treatment conditions on the production of LAL in preserved eggs were investigated. Preserved eggs were prepared using different times and temperatures, and alkali-pickling solutions with different types and concentrations of alkali and metal salts, and the corresponding LAL contents were measured. The results showed the following: during the pickling period of the preserved egg, the content of LAL in the egg white first rapidly increased and then slowly increased; the content of LAL in the egg yolk continued to increase significantly. During the aging period, the levels of LAL in both egg white and egg yolk slowly increased. The amounts of LAL in the preserved eggs were not significantly different at temperatures between 20 and 25ºC. At higher pickling temperatures, the LAL content in the preserved eggs increased. With the increase of alkali concentration in the alkali-pickling solution, the LAL content in the egg white and egg yolk showed an overall trend of an initial increase followed by a slight decrease. The content of LAL produced in preserved eggs treated with KOH was lower than in those treated with NaOH. NaCl and KCl produced no significant effects on the production of LAL in the preserved eggs. With increasing amounts of heavy metal salts, the LAL content in the preserved eggs first decreased and then increased. The LAL content generated in the CuSO4 group was lower than that in either the ZnSO4 or PbO groups. © 2015 Poultry Science Association Inc.

Theoretical study of the incompressible Navier-Stokes equations by the least-squares method

NASA Technical Reports Server (NTRS)

Jiang, Bo-Nan; Loh, Ching Y.; Povinelli, Louis A.

1994-01-01

Usually the theoretical analysis of the Navier-Stokes equations is conducted via the Galerkin method which leads to difficult saddle-point problems. This paper demonstrates that the least-squares method is a useful alternative tool for the theoretical study of partial differential equations since it leads to minimization problems which can often be treated by an elementary technique. The principal part of the Navier-Stokes equations in the first-order velocity-pressure-vorticity formulation consists of two div-curl systems, so the three-dimensional div-curl system is thoroughly studied at first. By introducing a dummy variable and by using the least-squares method, this paper shows that the div-curl system is properly determined and elliptic, and has a unique solution. The same technique then is employed to prove that the Stokes equations are properly determined and elliptic, and that four boundary conditions on a fixed boundary are required for three-dimensional problems. This paper also shows that under four combinations of non-standard boundary conditions the solution of the Stokes equations is unique. This paper emphasizes the application of the least-squares method and the div-curl method to derive a high-order version of differential equations and additional boundary conditions. In this paper, an elementary method (integration by parts) is used to prove Friedrichs' inequalities related to the div and curl operators which play an essential role in the analysis.

[Influence of carbodiimide-ethanol solution surface treatment on dentin microtensile bond strength].

PubMed

Zhang, Yi; Liu, Yu-hua; Zhou, Yong-sheng; Chung, Kwok-hung

2015-10-18

To evaluate the microtensile bond strength changes and patterns of fractures of the bonding interface after dentine surface treatment with carbodiimide-ethanol solution. 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) dissolved in ethanol was diluted into different concentrations of 2, 1, 0.3, 0.1 and 0.01 mol/L EDC-ethanol solutions. Twenty-eight caries-free extracted human third molars were ground metallurgically to prepare flat occlusal mid-coronal dentin surfaces and etched with 35% (mass fraction) phosphoric acid gel. Then they were treated with EDC-ethanol solution for 60 s before the bonding procedure and randomly divided into five experimental groups corresponding to the tested EDC-ethanol concentrations. The ethanol treated and no pre-treated surfaces were used as controls. Single Bond 2 adhesive was applied and resin composite disk was stacked on the treated dentine surface. The teeth with resin composite disks were stored in water at room temperature for 24 h and then sectioned longitudinally to produce stick specimens for microtensile bond strength test. Fracture patterns were observed with a stereomicroscope. The dentin surfaces pre-treated with 2 mol/L [(22.17±13.31) MPa] and 1 mol/L [(45.31±17.80) MPa] EDC-ethanol solutions resulted in statistically significant lower bond strength value (P<0.05). Increasing numbers of fracture pattern at the resin-dentin interface were also found in this two groups with percentages of 81.2% and 41.3% respectively. No significant difference was observed in the groups with 0.3, 0.1, 0.01 mol/L EDC surface treatment (P>0.05). No significant difference of immediate bond strengths was found in the 0.3, 0.1, 0.01 mol/L groups compared with the control group. EDC-ethanol solution surface treatment with concentrations of 2 mol/L and 1 mol/L resulted in decreasing of the bonding strength.

Selective mucosal ablation using CO2 laser for the development of novel endoscopic submucosal dissection: comparison of continuous wave and nanosecond pulsed wave

NASA Astrophysics Data System (ADS)

Ishii, K.; Watanabe, S.; Obata, D.; Hazama, H.; Morita, Y.; Matsuoka, Y.; Kutsumi, H.; Azuma, T.; Awazu, K.

2010-02-01

Endoscopic submucosal dissection (ESD) is accepted as a minimally invasive treatment technique for small early gastric cancers. Procedures are carried out using some specialized electrosurgical knifes with a submucosal injection solution. However it is not widely used because its procedure is difficult. The objective of this study is to develop a novel ESD method which is safe in principle and widely used by using laser techniques. In this study, we used CO2 lasers with a wavelength of 10.6 μm for mucosal ablation. Two types of pulse, continuous wave and pulsed wave with a pulse width of 110 ns, were studied to compare their values. Porcine stomach tissues were used as a sample. Aqueous solution of sodium hyaluronate (MucoUpR) with 50 mg/ml sodium dihydrogenphosphate is injected to a submucosal layer. As a result, ablation effect by CO2 laser irradiation was stopped because submucosal injection solution completely absorbed CO2 laser energy in the invasive energy condition which perforates a muscle layer without submucosal injection solution. Mucosal ablation by the combination of CO2 Laser and a submucosal injection solution is a feasible technique for treating early gastric cancers safely because it provides a selective mucosal resection and less-invasive interaction to muscle layer.

Nano-photo active cellulosic fabric through in situ phytosynthesis of star-like Ag/ZnO nanocomposites: Investigation and optimization of attributes associated with photocatalytic activity.

PubMed

Aladpoosh, Razieh; Montazer, Majid

2016-05-05

In this study, nano-photo active cellulosic fabric was prepared through in situ phytosynthesis of star-like Ag/ZnO nanocomposites using the ashes of Seidlitzia rosmarinus plants so-called Keliab. This is provided alkali media as a vital condition for synthesis of nanocomposites, further increasing the reduce-ability of cellulosic chains by activation of hydroxyl groups. The intermolecular dehydrolysis of intermediates ions under thermal and alkaline conditions leads to formation of Ag/ZnO heterostructure. Various analytical techniques were employed to confirm Ag/ZnO nanocomposites on the cotton fabric. The surface morphology, crystal phase and chemical structure of the treated fabrics were characterized by field emission and scanning electron microscopy (FE-SEM and SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDX). Moreover, influence of precursors: silver nitrate, zinc acetate and Keliab solution on attributes associated with photocatalytic activities including self-cleaning, whiteness and wettability was investigated via central composite design (CCD). The treated cotton samples exhibited self-cleaning activities through methylene blue degradation under day-light exposure along with improved wettability and whiteness. The prepared sample in optimized conditions showed good antibacterial activities against Staphylococcus aureus and Escherichia coli with enhanced fabric tensile strength. Copyright © 2016 Elsevier Ltd. All rights reserved.

Leaching and sorption of neonicotinoid insecticides and fungicides from seed coatings

USGS Publications Warehouse

Smalling, Kelly; Hladik, Michelle; Sanders, Corey; Kuivila, Kathryn

2018-01-01

Seed coatings are a treatment used on a variety of crops to improve production and offer protection against pests and fungal outbreaks. The leaching of the active ingredients associated with the seed coatings and the sorption to soil was evaluated under laboratory conditions using commercially available corn and soybean seeds to study the fate and transport of these pesticides under controlled conditions. The active ingredients (AI) included one neonicotinoid insecticide (thiamethoxam) and five fungicides (azoxystrobin, fludioxonil, metalaxyl, sedaxane thiabendazole). An aqueous leaching experiment was conducted with treated corn and soybean seeds. Leaching potential was a function of solubility and seed type. The leaching of fludioxonil, was dependent on seed type with a shorter time to equilibrium on the corn compared to the soybean seeds. Sorption experiments with the treated seeds and a solution of the AIs were conducted using three different soil types. Sorption behavior was a function of soil organic matter as well as seed type. For most AIs, a negative relationship was observed between the aqueous concentration and the log Koc. Sorption to all soils tested was limited for the hydrophilic pesticides thiamethoxam and metalaxyl. However, partitioning for the more hydrophobic fungicides was dependent on both seed type and soil properties. The mobility of fludioxonil in the sorption experiment varied by seed type indicating that the adjuvants associated with the seed coating could potentially play a role in the environmental fate of fludioxonil. This is the first study to assess, under laboratory conditions, the fate of pesticides associated with seed coatings using commercially available treated seeds. This information can be used to understand how alterations in agricultural practices (e.g., increasing use of seed treatments) can impact the exposure (concentration and duration) and potential effects of these chemicals to aquatic and terrestrial organisms.

Determinants of non-urgent Emergency Department attendance among females in Qatar.

PubMed

Read, Jen'nan Ghazal; Varughese, Shinu; Cameron, Peter A

2014-01-01

The use of emergency department (ED) services for non-urgent conditions is well-studied in many Western countries but much less so in the Middle East and Gulf region. While the consequences are universal-a drain on ED resources and poor patient outcomes-the causes and solutions are likely to be region and country specific. Unique social and economic circumstances also create gender-specific motivations for patient attendance. Alleviating demand on ED services requires understanding these circumstances, as past studies have shown. We undertook this study to understand why female patients with low-acuity conditions choose the emergency department in Qatar over other healthcare options. Prospective study at Hamad General Hospital's (HGH) emergency department female "see-and-treat" unit that treats low-acuity cases. One hundred female patients were purposively recruited to participate in the study. Three trained physicians conducted semi-structured interviews with patients over a three-month period after they had been treated and given informed consent. The study found that motivations for ED attendance were systematically influenced by employment status as an expatriate worker. Forty percent of the sample had been directed to the ED by their employers, and the vast majority (89%) of this group cited employer preference as the primary reason for choosing the ED. The interviews revealed that a major obstacle to workers using alternative facilities was the lack of a government-issued health card, which is available to all citizens and residents at a nominal rate. Reducing the number of low-acuity cases in the emergency department at HGH will require interventions aimed at encouraging patients with non-urgent conditions to use alternative healthcare facilities. Potential interventions include policy changes that require employers to either provide workers with a health card or compel employees to acquire one for themselves.

Recovery of yttrium from cathode ray tubes and lamps’ fluorescent powders: experimental results and economic simulation

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

Innocenzi, V., E-mail: valentina.innocenzi1@univaq.it; De Michelis, I.; Ferella, F.

2013-11-15

Highlights: • Fluorescent powder of lamps. • Fluorescent powder of cathode ray rubes. • Recovery of yttrium from fluorescent powders. • Economic simulation for the processes to recover yttrium from WEEE. - Abstract: In this paper, yttrium recovery from fluorescent powder of lamps and cathode ray tubes (CRTs) is described. The process for treating these materials includes the following: (a) acid leaching, (b) purification of the leach liquors using sodium hydroxide and sodium sulfide, (c) precipitation of yttrium using oxalic acid, and (d) calcinations of oxalates for production of yttrium oxides. Experimental results have shown that process conditions necessary tomore » purify the solutions and recover yttrium strongly depend on composition of the leach liquor, in other words, whether the powder comes from treatment of CRTs or lamp. In the optimal experimental conditions, the recoveries of yttrium oxide are about 95%, 55%, and 65% for CRT, lamps, and CRT/lamp mixture (called MIX) powders, respectively. The lower yields obtained during treatments of MIX and lamp powders are probably due to the co-precipitation of yttrium together with other metals contained in the lamps powder only. Yttrium loss can be reduced to minimum changing the experimental conditions with respect to the case of the CRT process. In any case, the purity of final products from CRT, lamps, and MIX is greater than 95%. Moreover, the possibility to treat simultaneously both CRT and lamp powders is very important and interesting from an industrial point of view since it could be possible to run a single plant treating fluorescent powder coming from two different electronic wastes.« less

Method For Creating Corrosion Resistant Surface On An Aluminum Copper Alloy

DOEpatents

Mansfeld, Florian B.; Wang, You; Lin, Simon H.

1997-06-03

A method for treating the surface of aluminum alloys hang a relatively high copper content is provided which includes the steps of removing substantially all of the copper from the surface, contacting the surface with a first solution containing cerium, electrically charging the surface while contacting the surface in an aqueous molybdate solution, and contacting the surface with a second solution containing cerium. The copper is substantially removed from the surface in the first step either by (i) contacting the surface with an acidic chromate solution or by (ii) contacting the surface with an acidic nitrate solution while subjecting the surface to an electric potential. The corrosion-resistant surface resulting from the invention is excellent, consistent and uniform throughout the surface. Surfaces treated by the invention may often be certified for use in salt-water services.

Successive construction of cellulase hyperproducers of Trichoderma using hyperpolyploids.

PubMed

Toyama, H; Toyama, N

2000-01-01

When the swollen conidia of Trichoderma reesei QM 6a are treated with 0.1% (w/v) colchicine solution, huge autopolyploid nuclei can be formed in those swollen conidia. When a mycelial mat derived from such a conidum is treated with a haploidizing reagent, benomyl, many fan-shaped sectors are produced from the colony, and cellulase hyperproducers are selected from conidia on the colony. When colchicine and benomyl treatments are repeated on cellulase hyperproducers, new hyperproducers can be constructed successively and systematically. Moreover, when conidia derived from autopolyploids are treated with ethylmethanesulfonate solution, another type of cellulase hyperproducers (polyploids) can be obtained.

The action of ultrasounds on Bezostaia 1 winter wheat grown in sand pots treated with Knop solution

NASA Technical Reports Server (NTRS)

Albu, N.

1974-01-01

The results of 3 years of research are presented concerning the increase in length and weight of the aerial biomass as compared with the underground biomass, as well as the productivity indexes of Bezostaia 1 winter wheat. The experiment involved two varieties, each of them with nine repetitions. Sterile sifted sand treated several times with a Knop solution during the vegetative period was used as a seed bed. The seeds were kept in water for 2 hours before treatment. Biometric and statistical measurements showed significant responses in the treated varieties.

Spreading of a Lidocaine Formulation on Microneedle-Treated Skin.

PubMed

Nayak, Atul; Das, Diganta B; Chao, Tzu C; Starov, Victor M

2015-12-01

The spreadability of a liquid drug formulation on skin is an indication of it either remaining stationary or distributing (spreading) as a droplet. Factors determining droplet spreadability of the formulation are spreading area, diameter of the droplet base, viscosity of the liquid, contact angle, volume of droplet on skin and any others. The creation of microcavities from the application of microneedle (MN) has the potential to control droplet spreading, and hence, target specific areas of skin for drug delivery. However, there is little work that demonstrates spreading of liquid drug formulation on MN-treated skin. Below, spreading of a lidocaine hydrogel formulation and lidocaine solution (reference liquid) on porcine skin is investigated over MN-treated skin. Controlled spreadability was achieved with the lidocaine hydrogel on MN-treated skin as compared with lidocaine solution. It was observed that the droplet spreading parameters such as spreading radius, droplet height and dynamic contact angle were slightly lower for the lidocaine hydrogel than the lidocaine solution on skin. Also, the lidocaine hydrogel on MN-treated skin resulted in slower dynamic reduction of droplet height, contact angle and reduced time taken in attaining static advancing droplets because of the MN microcavities. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Synergistic and antagonistic interactions between bednets and vaccines in the control of malaria.

PubMed

Artzy-Randrup, Yael; Dobson, Andrew P; Pascual, Mercedes

2015-03-10

It is extremely likely that the malaria vaccines currently in development will be used in conjunction with treated bednets and other forms of malaria control. The interaction of different intervention methods is at present poorly understood in a disease such as malaria where immunity is more complex than for other pathogens that have been successfully controlled by vaccination. Here we develop a general mathematical model of malaria transmission to examine the interaction between vaccination and bednets. Counterintuitively, we find that the frailty of malaria immunity will potentially cause both synergistic and antagonistic interactions between vaccination and the use of bednets. We explore the conditions that create these tensions, and outline strategies that minimize their detrimental impact. Our analysis specifically considers the three leading vaccine classes currently in development: preerythrocytic (PEV), blood stage (BSV), and transmission blocking (TBV). We find that the combination of BSV with treated bednets can lead to increased morbidity with no added value in terms of elimination; the interaction is clearly antagonistic. In contrast, there is strong synergy between PEV and treated bednets that may facilitate elimination, although transient stages are likely to increase morbidity. The combination of TBV with treated bednets is synergistic, lowering both morbidity and elimination thresholds. Our results suggest that vaccines will not provide a straightforward solution to malaria control, and that future programs need to consider the synergistic and antagonistic interactions between vaccines and treated bednets.

Explicitly represented polygon wall boundary model for the explicit MPS method

NASA Astrophysics Data System (ADS)

Mitsume, Naoto; Yoshimura, Shinobu; Murotani, Kohei; Yamada, Tomonori

2015-05-01

This study presents an accurate and robust boundary model, the explicitly represented polygon (ERP) wall boundary model, to treat arbitrarily shaped wall boundaries in the explicit moving particle simulation (E-MPS) method, which is a mesh-free particle method for strong form partial differential equations. The ERP model expresses wall boundaries as polygons, which are explicitly represented without using the distance function. These are derived so that for viscous fluids, and with less computational cost, they satisfy the Neumann boundary condition for the pressure and the slip/no-slip condition on the wall surface. The proposed model is verified and validated by comparing computed results with the theoretical solution, results obtained by other models, and experimental results. Two simulations with complex boundary movements are conducted to demonstrate the applicability of the E-MPS method to the ERP model.

Influence of coating defects on the corrosion behavior of cold sprayed refractory metals

NASA Astrophysics Data System (ADS)

Kumar, S.; Rao, A. Arjuna

2017-02-01

The defects in the cold sprayed coatings are critical in the case of corrosion performances of the coatings in aggressive conditions. To understand the influence of coating defects on corrosion, immersion tests have been carried out in HF solution for the cold sprayed and heat treated Titanium, Tantalum and Niobium coatings. Long duration immersion tests reveal inhomogeneous weight losses of the samples prepared at different heat treatment conditions. The weight loss for different coatings has been well corroborated with the coating defects and microstructures. Chemical and micro structural analysis elucidates the reason behind the inhomogeneous performance of different type of cold sprayed coatings in corrosion medium. In the case of cold sprayed titanium, formation of stable oxide along the inter-splat boundary hinders the aggressive attack of the corrosion medium which is not so in other cases.

Phases, periphases, and interphases equilibrium by molecular modeling. I. Mass equilibrium by the semianalytical stochastic perturbations method and application to a solution between (120) gypsum faces

NASA Astrophysics Data System (ADS)

Pedesseau, Laurent; Jouanna, Paul

2004-12-01

The SASP (semianalytical stochastic perturbations) method is an original mixed macro-nano-approach dedicated to the mass equilibrium of multispecies phases, periphases, and interphases. This general method, applied here to the reflexive relation Ck⇔μk between the concentrations Ck and the chemical potentials μk of k species within a fluid in equilibrium, leads to the distribution of the particles at the atomic scale. The macroaspects of the method, based on analytical Taylor's developments of chemical potentials, are intimately mixed with the nanoaspects of molecular mechanics computations on stochastically perturbed states. This numerical approach, directly linked to definitions, is universal by comparison with current approaches, DLVO Derjaguin-Landau-Verwey-Overbeek, grand canonical Monte Carlo, etc., without any restriction on the number of species, concentrations, or boundary conditions. The determination of the relation Ck⇔μk implies in fact two problems: a direct problem Ck⇒μk and an inverse problem μk⇒Ck. Validation of the method is demonstrated in case studies A and B which treat, respectively, a direct problem and an inverse problem within a free saturated gypsum solution. The flexibility of the method is illustrated in case study C dealing with an inverse problem within a solution interphase, confined between two (120) gypsum faces, remaining in connection with a reference solution. This last inverse problem leads to the mass equilibrium of ions and water molecules within a 3 Å thick gypsum interface. The major unexpected observation is the repulsion of SO42- ions towards the reference solution and the attraction of Ca2+ ions from the reference solution, the concentration being 50 times higher within the interphase as compared to the free solution. The SASP method is today the unique approach able to tackle the simulation of the number and distribution of ions plus water molecules in such extreme confined conditions. This result is of prime importance for all coupled chemical-mechanical problems dealing with interfaces, and more generally for a wide variety of applications such as phase changes, osmotic equilibrium, surface energy, etc., in complex chemical-physics situations.

PLUTONIUM-CUPFERRON COMPLEX AND METHOD OF REMOVING PLUTONIUM FROM SOLUTION

DOEpatents

Potratz, H.A.

1959-01-13

A method is presented for separating plutonium from fission products present in solutions of neutronirradiated uranium. The process consists in treating such acidic solutions with cupferron so that the cupferron reacts with the plutonium present to form an insoluble complex. This plutonium cupferride precipitates and may then be separated from the solution.

Is thermal dispersivity significant for the use of heat as a tracer?

NASA Astrophysics Data System (ADS)

Rau, G. C.; Andersen, M. S.; Acworth, I.

2011-12-01

Heat profiles are regularly used to estimate sediment thermal parameters and to quantify vertical water flow velocity in fully saturated porous media. However, it has been pointed out by several authors that there is disagreement regarding the use of thermal dispersivity in heat transport models [e.g. Anderson, 2005]. Some researchers argue that this term should be treated analogous to solute transport [e.g. de Marsily, 1986], whilst others state that because heat diffusion is much faster than solute diffusion the dispersivity term can be neglected [e.g. Ingebritsen and Sanford, 1998]. This issue has never been properly addressed experimentally for environmentally relevant conditions. In order to address this question a hydraulic laboratory experiment was designed to investigate heat transport for different steady-state uniform flow velocities in the Darcy range (between 0 and 100 m/d) through homogeneous sand. For each flow velocity a point heat source at the center of the tank was instantaneously activated, and the thermal response was measured at 27 different locations using high resolution temperature probes. For the same flow velocities, a solute slug was injected in the center of the tank and the solute slug breakthrough was measured using 3 fluid EC sensors at different distances downstream of the injection point. This enabled direct comparison of solute and heat transport under identical conditions. The recorded temperature time-series data were used to calculate the thermal properties of the sand for conduction only, and estimate water flow velocity and thermal dispersion. The recorded EC time-series data were used to independently estimate water flow velocity but also solute dispersivity. The analytical solution for the solute transport case [Hunt, 1978] was adapted for heat transport and extended to account for slightly non-ideal experiment conditions. Velocity results independently derived from solute and heat show a discrepancy of up to 20%. The reason for this is not clear. Furthermore, the results show that thermal dispersivity can best be approximated with a square dependency on flow velocity. This agrees with earlier experiments in ideal materials by Green et al. [1964] as well as theoretical derivations [Kaviany, 1995]. However, this is in contrast to the linear dispersion model which has been adapted from solute transport and is commonly used in groundwater studies. The experimental results can be visualized in a conceptual plot devised by Bear [1972] for solute dispersion data (Figure 1). From this it becomes clear that the heat and solute transport Peclet numbers differs by several orders of magnitude for the same flow velocity and material because diffusion of heat is much faster than solute diffusion. As a result, the same Darcy flow range covers a different Peclet number range in heat transport and solute transport. This explains the controversy in the hydrologic community regarding the use of thermal dispersivity in transport models. In summary, for this experiment thermal dispersivity can be neglected when thermal Pe < 0.5, but should be considered for Pe > 0.5 with a square dependency on velocity.

Efinaconazole Topical Solution, 10%: Efficacy in Patients with Onychomycosis and Coexisting Tinea Pedis.

PubMed

Markinson, Bryan C; Caldwell, Bryan D

2015-04-13

We sought to evaluate the efficacy of efinaconazole topical solution, 10%, in patients with onychomycosis and coexisting tinea pedis. We analyzed 1,655 patients, aged 18 to 70 years, randomized (3:1) to receive efinaconazole topical solution, 10%, or vehicle from two identical multicenter, double-blind, vehicle-controlled 48-week studies evaluating safety and efficacy. The primary end point was complete cure rate (0% clinical involvement of the target toenail and negative potassium hydroxide examination and fungal culture findings) at week 52. Three groups were compared: patients with onychomycosis and coexisting interdigital tinea pedis on-study (treated or left untreated) and those with no coexisting tinea pedis. Treatment with efinaconazole topical solution, 10%, was significantly more effective than vehicle use irrespective of the coexistence of tinea pedis or its treatment. Overall, 352 patients with onychomycosis (21.3%) had coexisting interdigital tinea pedis at baseline, with 215 of these patients (61.1%) receiving investigator-approved topical antifungal agents for their tinea pedis in addition to their randomized onychomycosis treatment. At week 52, efinaconazole complete cure rates of 29.4% were reported in patients with onychomycosis when coexisting tinea pedis was treated compared with 16.1% when coexisting tinea pedis was not treated. Both cure rates were significant compared with vehicle (P = .003 and .045, respectively), and in the latter subgroup, no patients treated with vehicle achieved a complete cure. Treatment of coexisting tinea pedis in patients with onychomycosis enhances the efficacy of once-daily topical treatment with efinaconazole topical solution, 10%.

Efinaconazole Topical Solution, 10% Efficacy in Patients with Onychomycosis and Coexisting Tinea Pedis.

PubMed

Markinson, Bryan; Caldwell, Bryan

2015-09-01

We sought to evaluate the efficacy of efinaconazole topical solution, 10%, in patients with onychomycosis and coexisting tinea pedis. We analyzed 1,655 patients, aged 18 to 70 years, randomized (3:1) to receive efinaconazole topical solution, 10%, or vehicle from two identical multicenter, double-blind, vehicle-controlled 48-week studies evaluating safety and efficacy. The primary end point was complete cure rate (0% clinical involvement of the target toenail and negative potassium hydroxide examination and fungal culture findings) at week 52. Three groups were compared: patients with onychomycosis and coexisting interdigital tinea pedis on-study (treated or left untreated) and those with no coexisting tinea pedis. Treatment with efinaconazole topical solution, 10%, was significantly more effective than vehicle use irrespective of the coexistence of tinea pedis or its treatment. Overall, 352 patients with onychomycosis (21.3%) had coexisting interdigital tinea pedis, with 215 of these patients (61.1%) receiving investigator-approved topical antifungal agents for their tinea pedis in addition to their randomized onychomycosis treatment. At week 52, efinaconazole complete cure rates of 29.4% were reported in patients with onychomycosis when coexisting tinea pedis was treated compared with 16.1% when coexisting tinea pedis was not treated. Both cure rates were significant compared with vehicle (P = .003 and .045, respectively), and in the latter subgroup, no patients treated with vehicle achieved a complete cure. Treatment of coexisting tinea pedis in patients with onychomycosis enhances the efficacy of once-daily topical treatment with efinaconazole topical solution, 10%.

Ca(OH)[sub 2]-treated ceramic microsphere

DOEpatents

Sugama, Toshifumi.

1989-04-18

Geothermal wells with lost circulation problems are treated with a lightweight, high temperature (i.e. 350 C) cement slurry which incorporates pressure resistant hollow microspheres into the slurry wherein the spheres have been pretreated with an alkali compound such as Ca(OH)[sub 2] for up to 20 hours and at 100--300 C. Preferably, the alkali solution is a saturated aqueous solution and the treatment is for 10 hours. 2 figs.

Ca(OH)[sub 2]-treated ceramic microsphere

DOEpatents

Sugama, Toshifumi.

1990-06-26

Geothermal wells with lost circulation problems are treated with a lightweight, high temperature (i.e. 350 C) cement slurry which incorporates pressure resistant hollow microspheres into the slurry wherein the spheres have been pretreated with an alkali compound such as Ca(OH)[sub 2] for up to 20 hours and at 100--300 C. Preferably, the alkali solution is a saturated aqueous solution and the treatment is for 10 hours. 2 figs.

Recent advances in f-element separations based on a new method for the production of pentavalent americium in acidic solution

DOE PAGES

Mincher, Bruce J.; Schmitt, Nicholas C.; Schuetz, Brian K.; ...

2015-03-11

The peroxydisulfate anion has long been used for the preparation of hexavalent americium (Am VI) from the normally stable Am III valence state in mildly acidic solutions. However, there has been no satisfactory means to directly prepare the pentavalent state (Am V) in that medium. Some early literature reports indicated that the peroxydisulfate oxidation was incomplete, and silver ion catalysis in conjunction with peroxydisulfate became accepted as the means to ensure quantitative generation of Am VI. Incomplete oxidation would be expected to leave residual Am III, or to produce Am V in treated solutions. However, until recently, the use ofmore » peroxydisulfate as an Am V reagent has not been reported. Here, parameters influencing the oxidation were investigated, including peroxydisulfate and acid concentration, temperature, duration of oxidative treatment, and the presence of higher concentrations of other redox active metals such as plutonium. Using optimized conditions determined here, quantitative Am V was prepared in an acidic solution and the UV/Vis extinction coefficients of the Am V 513 nm peak were measured over a range of nitric acid concentrations. Furthermore, the utility of Am V for separations from the lanthanides and curium by solvent extraction, organic column chromatography and inorganic ion exchangers was also investigated.« less

Degradation of the endocrine disrupting chemicals (EDCs) carbamazepine, clofibric acid, and iopromide by corona discharge over water.

PubMed

Krause, Holger; Schweiger, Bianca; Schuhmacher, Jörg; Scholl, Saskia; Steinfeld, Ute

2009-04-01

Common wastewater treatment plants often do not eliminate endocrine disrupting chemicals (EDCs). Aqueous solutions of three EDCs were treated with an enhanced corona discharge technology. The three EDCs were clofibric acid, a blood lipid regulator, carbamazepine, an antiepileptic drug, and iopromide, a contrast media. To simulate real conditions, EDC solutions containing landfill leachate were also used. In our setup, two barrier electrodes provided an atmospheric pressure corona discharge over a thin water film, in which the counter-electrode was submerged. Clofibric acid, carbamazepine, and iopromide were effectively removed from a single solution. After a treatment of 15min, there were no traces of iopromide estrogen activity either as a single substance or as degradation products when using an E-Screen Assay. Continuous treatment was compared with pulsed treatment using carbamazepine solutions mixed with pretreated landfill leachate. Best degradation results were achieved with a 500 W continuous duty cycle treatment. Counter-electrodes from materials such as boron doped diamond (BDD), titanium iridium oxide, and iron were investigated for their influences on the process effectivity. Significant improvements were achieved by using an enclosed reactor, BDD electrodes, and circulating only a fresh air or argon/air mixture as cooling gas through the barrier electrodes.

Clinical utility of 3% diquafosol ophthalmic solution in the treatment of dry eyes

PubMed Central

Koh, Shizuka

2015-01-01

Diquafosol is a drug used for dry eye treatment with a novel mechanism of action. It stimulates the secretion of tear fluid and mucin on the ocular surface, thus enabling us to selectively treat the tear film layer, playing an important role in the establishment of the concept of “Tear Film Oriented Therapy (TFOT)”, an effective therapeutic approach to dry eye in Japan. The 3% diquafosol ophthalmic solution has been widely used for the treatment of dry eye in clinical practice, and it is currently available in Japan and South Korea. This review provides an overview of the clinical utility of 3% diquafosol ophthalmic solution, focusing on the results of clinical studies on various types of dry eye, including aqueous-deficient dry eye, short tear film breakup time-type dry eye, and post dry eye after laser in situ keratomileusis. It also introduces the additive effect of diquafosol on sodium hyaluronate monotherapy for dry eye, and the effect of 3% diquafosol ophthalmic solution for dry eye-related conditions. Additionally, it summarizes the ocular effects of diquafosol in healthy human eyes. Lastly, the importance of improving tear film stability in dry eye treatment, as well as general advances in dry eye treatments, are described. PMID:26028958

Clinical utility of 3% diquafosol ophthalmic solution in the treatment of dry eyes.

PubMed

Koh, Shizuka

2015-01-01

Diquafosol is a drug used for dry eye treatment with a novel mechanism of action. It stimulates the secretion of tear fluid and mucin on the ocular surface, thus enabling us to selectively treat the tear film layer, playing an important role in the establishment of the concept of "Tear Film Oriented Therapy (TFOT)", an effective therapeutic approach to dry eye in Japan. The 3% diquafosol ophthalmic solution has been widely used for the treatment of dry eye in clinical practice, and it is currently available in Japan and South Korea. This review provides an overview of the clinical utility of 3% diquafosol ophthalmic solution, focusing on the results of clinical studies on various types of dry eye, including aqueous-deficient dry eye, short tear film breakup time-type dry eye, and post dry eye after laser in situ keratomileusis. It also introduces the additive effect of diquafosol on sodium hyaluronate monotherapy for dry eye, and the effect of 3% diquafosol ophthalmic solution for dry eye-related conditions. Additionally, it summarizes the ocular effects of diquafosol in healthy human eyes. Lastly, the importance of improving tear film stability in dry eye treatment, as well as general advances in dry eye treatments, are described.

Managing the potential risks of using bacteria-laden water in mineral processing to protect freshwater.

PubMed

Liu, Wenying; Moran, Chris J; Vink, Sue

2013-06-18

The minerals industry is being driven to access multiple water sources and increase water reuse to minimize freshwater withdrawal. Bacteria-laden water, such as treated effluent, has been increasingly used as an alternative to freshwater for mineral processing, in particular flotation, where conditions are favorable for bacterial growth. However, the risk posed by bacteria to flotation efficiency is poorly understood. This could be a barrier to the ongoing use of this water source. This study tested the potential of a previously published risk-based approach as a management tool to both assist mine sites in quantifying the risk from bacteria, and finding system-wide cost-effective solutions for risk mitigation. The result shows that the solution of adjusting the flotation chemical regime could only partly control the risk. The second solution of using tailings as an absorbent was shown to be effective in the laboratory in reducing bacterial concentration and thus removing the threat to flotation recovery. The best solution is likely to combine internal and external approaches, that is, inside and outside processing plants. Findings in this study contribute possible methods applicable to managing the risk from water-borne bacteria to plant operations that choose to use bacteria-containing water, when attempting to minimize freshwater use, and avoiding the undesirable consequences of increasing its use.

Humic substances as a washing agent for Cd-contaminated soils.

PubMed

Meng, Fande; Yuan, Guodong; Wei, Jing; Bi, Dongxue; Ok, Yong Sik; Wang, Hailong

2017-08-01

Cost-effective and eco-friendly washing agents are in demand for Cd contaminated soils. Here, we used leonardite-derived humic substances to wash different types of Cd-contaminated soils, namely, a silty loam (Soil 1), a silty clay loam (Soil 2), and a sandy loam (Soil 3). Washing conditions were investigated for their effects on Cd removal efficiency. Cadmium removal was enhanced by a high humic substance concentration, long washing time, near neutral pH, and large solution/soil ratio. Based on the tradeoff between efficiency and cost, an optimum working condition was established as follows: humic substance concentration (3150 mg C/L), solution pH (6.0), washing time (2 h) and a washing solution/soil ratio (5). A single washing removed 0.55 mg Cd/kg from Soil 1 (1.33 mg Cd/kg), 2.32 mg Cd/kg from Soil 2 (6.57 mg Cd/kg), and 1.97 mg Cd/kg from Soil 3 (2.63 mg Cd/kg). Cd in effluents was effectively treated by adding a small dose of calcium hydroxide, reducing its concentration below the discharge limit of 0.1 mg/L in China. Being cost-effective and safe, humic substances have a great potential to replace common washing agents for the remediation of Cd-contaminated soils. Besides being environmentally benign, humic substances can improve soil physical, chemical, and biological properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solitons in Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Carr, Lincoln D.

2003-05-01

The stationary form, dynamical properties, and experimental criteria for creation of matter-wave bright and dark solitons, both singly and in trains, are studied numerically and analytically in the context of Bose-Einstein condensates [1]. The full set of stationary solutions in closed analytic form to the mean field model in the quasi-one-dimensional regime, which is a nonlinear Schrodinger equation equally relevant in nonlinear optics, is developed under periodic and box boundary conditions [2]. These solutions are extended numerically into the two and three dimensional regimes, where it is shown that dark solitons can be used to create vortex-anti-vortex pairs under realistic conditions. Specific experimental prescriptions for creating viable dark and bright solitons in the quasi-one-dimensional regime are provided. These analytic methods are then extended to treat the nonlinear Schrodinger equation with a generalized lattice potential, which models a Bose-Einstein condensate trapped in the potential generated by a standing light wave. A novel solution family is developed and stability criterion are presented. Experiments which successfully carried out these ideas are briefly discussed [3]. [1] Dissertation research completed at the University of Washington Physics Department under the advisorship of Prof. William P. Reinhardt. [2] L. D. Carr, C. W. Clark, and W. P. Reinhardt, Phys. Rev. A v. 62 p. 063610-1--10 and Phys. Rev. A v.62, p.063611-1--10 (2000). [3] L. Khaykovich, F. Schreck, T. Bourdel, J. Cubizolles, G. Ferrari, L. D. Carr, Y. Castin, and C. Salomon, Science v. 296, p.1290--1293 (2002).

Treatment of selected pharmaceuticals by ferrate(VI): performance, kinetic studies and identification of oxidation products.

PubMed

Zhou, Zhengwei; Jiang, Jia-Qian

2015-03-15

The performance of ferrate(VI) in treating sulfamethoxazole (SMX), diclofenac (DCF), carbamazepine (CBZ) and bezafibrate (BZF) in test solutions containing the four compounds was investigated. A series of jar-test experiments was performed on a bench-scale at pH 6-9 and at a ferrate(VI) dose of 1-5 mg Fe/L. The results suggested that ferrate(VI) can effectively remove SMX, DCF and CBZ from the test solutions, with greater than 80% removal under optimum conditions. However, the removal efficiency of BZF was very low, less than 25% under the studied conditions. Increasing the dose of ferrate(VI) improved the treatment performance, while the influence of solution pH on ferrate(VI) performance varied among the different target compounds. Ferrate(VI) demonstrated the highest reactivity with SMX at pH 8 and pH 9 (20 °C), with apparent second-order rate constants of 360±17 M(-1) s(-1) and 1.26±0.02 M(-1) s(-1), respectively. However, BZF showed the lowest removal by ferrate(VI) with the smallest rate constants (less than 0.5 M(-1) s(-1)) at pH 8 and pH 9. Furthermore, a number of oxidation products (OPs) of SMX, DCF and CBZ during ferrate(VI) oxidation were detected by liquid chromatography and mass spectrometry (LC-MS), and their degradation pathways were tentatively proposed. No OPs of BZF were detected during ferrate(VI) oxidation. Copyright © 2014 Elsevier B.V. All rights reserved.

Decolorization of acid and basic dyes: understanding the metabolic degradation and cell-induced adsorption/precipitation by Escherichia coli.

PubMed

Cerboneschi, Matteo; Corsi, Massimo; Bianchini, Roberto; Bonanni, Marco; Tegli, Stefania

2015-10-01

Escherichia coli strain DH5α was successfully employed in the decolorization of commercial anthraquinone and azo dyes, belonging to the general classes of acid or basic dyes. The bacteria showed an aptitude to survive at different pH values on any dye solution tested, and a rapid decolorization was obtained under aerobic conditions for the whole collection of dyes. A deep investigation about the mode of action of E. coli was carried out to demonstrate that dye decolorization mainly occurred via three different pathways, specifically bacterial induced precipitation, cell wall adsorption, and metabolism, whose weight was correlated with the chemical nature of the dye. In the case of basic azo dyes, an unexpected fast decolorization was observed after just 2-h postinoculation under aerobic conditions, suggesting that metabolism was the main mechanism involved in basic azo dye degradation, as unequivocally demonstrated by mass spectrometric analysis. The reductive cleavage of the azo group by E. coli on basic azo dyes was also further demonstrated by the inhibition of decolorization occurring when glucose was added to the dye solution. Moreover, no residual toxicity was found in the E. coli-treated basic azo dye solutions by performing Daphnia magna acute toxicity assays. The results of the present study demonstrated that E. coli can be simply exploited for its natural metabolic pathways, without applying any recombinant technology. The high versatility and adaptability of this bacterium could encourage its involvement in industrial bioremediation of textile and leather dyeing wastewaters.

Strength conditions for the elastic structures with a stress error

NASA Astrophysics Data System (ADS)

Matveev, A. D.

2017-10-01

As is known, the constraints (strength conditions) for the safety factor of elastic structures and design details of a particular class, e.g. aviation structures are established, i.e. the safety factor values of such structures should be within the given range. It should be noted that the constraints are set for the safety factors corresponding to analytical (exact) solutions of elasticity problems represented for the structures. Developing the analytical solutions for most structures, especially irregular shape ones, is associated with great difficulties. Approximate approaches to solve the elasticity problems, e.g. the technical theories of deformation of homogeneous and composite plates, beams and shells, are widely used for a great number of structures. Technical theories based on the hypotheses give rise to approximate (technical) solutions with an irreducible error, with the exact value being difficult to be determined. In static calculations of the structural strength with a specified small range for the safety factors application of technical (by the Theory of Strength of Materials) solutions is difficult. However, there are some numerical methods for developing the approximate solutions of elasticity problems with arbitrarily small errors. In present paper, the adjusted reference (specified) strength conditions for the structural safety factor corresponding to approximate solution of the elasticity problem have been proposed. The stress error estimation is taken into account using the proposed strength conditions. It has been shown that, to fulfill the specified strength conditions for the safety factor of the given structure corresponding to an exact solution, the adjusted strength conditions for the structural safety factor corresponding to an approximate solution are required. The stress error estimation which is the basis for developing the adjusted strength conditions has been determined for the specified strength conditions. The adjusted strength conditions presented by allowable stresses are suggested. Adjusted strength conditions make it possible to determine the set of approximate solutions, whereby meeting the specified strength conditions. Some examples of the specified strength conditions to be satisfied using the technical (by the Theory of Strength of Materials) solutions and strength conditions have been given, as well as the examples of stress conditions to be satisfied using approximate solutions with a small error.

Antimicrobial Applications of Ambient--Air Plasmas

NASA Astrophysics Data System (ADS)

Pavlovich, Matthew John

The emerging field of plasma biotechology studies the applications of the plasma phase of matter to biological systems. "Ambient-condition" plasmas created at or near room temperature and atmospheric pressure are especially promising for biomedical applications because of their convenience, safety to patients, and compatibility with existing medical technology. Plasmas can be created from many different gases; plasma made from air contains a number of reactive oxygen and nitrogen species, or RONS, involved in various biological processes, including immune activity, signaling, and gene expression. Therefore, ambient-condition air plasma is of particular interest for biological applications. To understand and predict the effects of treating biological systems with ambient-air plasma, it is necessary to characterize and measure the chemical species that these plasmas produce. Understanding both gaseous chemistry and the chemistry in plasma-treated aqueous solution is important because many biological systems exist in aqueous media. Existing literature about ambient-air plasma hypothesizes the critical role of reactive oxygen and nitrogen species; a major aim of this dissertation is to better quantify RONS by produced ambient-air plasma and understand how RONS chemistry changes in response to different plasma processing conditions. Measurements imply that both gaseous and aqueous chemistry are highly sensitive to operating conditions. In particular, chemical species in air treated by plasma exist in either a low-power ozone-dominated mode or a high-power nitrogen oxide-dominated mode, with an unstable transition region at intermediate discharge power and treatment time. Ozone (O3) and nitrogen oxides (NO and NO2, or NOx) are mutually exclusive in this system and that the transition region corresponds to the transition from ozone- to nitrogen oxides-mode. Aqueous chemistry agrees well with to air plasma chemistry, and a similar transition in liquid-phase composition from ozone mode to nitrogen oxides mode occurs as the discharge power increases. One prominent example of plasma biotechnology is the use of plasma-derived reactive species as a novel disinfectant. Ambient-air plasma is an attractive means of disinfection because it is non-thermal, expends a small amount of power, and requires only air and electricity to operate. Both solid surfaces and liquid volumes can be effectively and efficiently decontaminated by the reactive oxygen and nitrogen species that plasma generates. Dry surfaces are decontaminated most effectively by the plasma operating in NOx mode and less effectively in ozone mode, with the weakest antibacterial effects in the transition region, and neutral reactive species are more influential in surface disinfection than charged particles. Aqueous bacterial inactivation correlates well with ozone concentration, suggesting that ozone is the dominant species for bacterial inactivation under the condition of a low-power discharge. Alternatively, air plasma operating in the higher-power, nitrogen oxides-rich mode can create a persistently antibacterial solution. Finally, when near-UV (UVA) treatment follows plasma treatment of bacterial suspension, the antimicrobial effect exceeds the effect predicted from the two treatments alone, and addition of nitrite to aqueous solution, followed by photolysis of nitrite by UVA photons, is hypothesized as the primary mechanism of synergy. The results presented in this dissertation underscore the dynamic nature of air plasma chemistry and the importance of careful chemical characterization of plasma devices intended for biological applications. The complexity of atmospheric pressure plasma devices, and their sensitivity to subtle differences in design and operation, can lead to different results with different mechanisms.

Characterization of a Laser Surface-Treated Martensitic Stainless Steel.

PubMed

Al-Sayed, S R; Hussein, A A; Nofal, A A; Hassab Elnaby, S I; Elgazzar, H

2017-05-29

Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W) with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m•min-1) was adopted to reach the optimum conditions for impact toughness, wear, and corrosion resistance for laser heat treated (LHT) samples. The 0 °C impact energy of LHT samples indicated higher values compared to the conventionally heat treated (CHT) samples. This was accompanied by the formation of a hard surface layer and a soft interior base metal. Microhardness was studied to determine the variation of hardness values with respect to the depth under the treated surface. The wear resistance at the surface was enhanced considerably. Microstructure examination was characterized using optical and scanning electron microscopes. The corrosion behavior of the LHT samples was also studied and its correlation with the microstructures was determined. The corrosion data was obtained in 3.5% NaCl solution at room temperature by means of a potentiodynamic polarization technique.

Characterization of a Laser Surface-Treated Martensitic Stainless Steel

PubMed Central

Al-Sayed, S. R.; Hussein, A. A.; Nofal, A. A.; Hassab Elnaby, S. I.; Elgazzar, H.

2017-01-01

Laser surface treatment was carried out on AISI 416 machinable martensitic stainless steel containing 0.225 wt.% sulfur. Nd:YAG laser with a 2.2-KW continuous wave was used. The aim was to compare the physical and chemical properties achieved by this type of selective surface treatment with those achieved by the conventional treatment. Laser power of different values (700 and 1000 W) with four corresponding different laser scanning speeds (0.5, 1, 2, and 3 m·min−1) was adopted to reach the optimum conditions for impact toughness, wear, and corrosion resistance for laser heat treated (LHT) samples. The 0 °C impact energy of LHT samples indicated higher values compared to the conventionally heat treated (CHT) samples. This was accompanied by the formation of a hard surface layer and a soft interior base metal. Microhardness was studied to determine the variation of hardness values with respect to the depth under the treated surface. The wear resistance at the surface was enhanced considerably. Microstructure examination was characterized using optical and scanning electron microscopes. The corrosion behavior of the LHT samples was also studied and its correlation with the microstructures was determined. The corrosion data was obtained in 3.5% NaCl solution at room temperature by means of a potentiodynamic polarization technique. PMID:28772955

ENGINEERING BULLETIN: AIR STRIPPING OF AQUEOUS SOLUTIONS

EPA Science Inventory

Air striding is a means to transfer contaminants from aqueous solutions to air. ontaminants are not destroyed by air stripping but are physically separated from the aqueous solutions. ontaminant vapors are transferred into the air stream and, if necessary, can be treated by incin...

Low-dose 5-fluorouracil in combination with salicylic acid for the treatment of actinic keratoses on the hands and/or forearms - results of a non-interventional study.

PubMed

Reinhold, U; Hadshiew, I; Melzer, A; Prechtl, A

2017-03-01

As an in situ carcinoma, actinic keratoses should be treated early. Previous studies on the efficacy of a low-dose 0.5% 5-fluorouracil solution in combination with 10% salicylic acid (low-dose 5-FU/SA) are mostly related to lesions appearing on the head and face. In contrast, actinic keratoses (AK) lesions of the upper extremities are considered to be difficult to treat. The efficacy of low-dose 5-FU/SA in the treatment of actinic keratoses on the hands and/or forearms was studied for the first time in this non-interventional study (NIS) under practical conditions in a large patient population. In addition to the clinical course during therapy and a follow-up period, the length of application and adherence were documented. As part of this NIS, 649 patients with AK were treated at 207 centres with low-dose 5-FU/SA. The data of the study were recorded at baseline, optionally during an intermediate examination, at the end of therapy and during a final assessment. The average number of AK lesions decreased during the entire observation period by 92%. Side-effects were documented only rarely in the form of local skin reactions (2%). The attending physicians assessed the efficacy, tolerability and safety of the therapy as being predominantly very good or good (in each case ≥90%). AK lesions on the hands and/or forearms were effectively treated with low-dose 5-FU/SA under routine conditions in dermatological practice and the treatment was well tolerated. © 2016 European Academy of Dermatology and Venereology.

Efficacy of chlorine dioxide against Listeria monocytogenes in brine chilling solutions.

PubMed

Valderrama, W B; Mills, E W; Cutter, C N

2009-11-01

Chilled brine solutions are used by the food industry to rapidly cool ready-to-eat meat products after cooking and before packaging. Chlorine dioxide (ClO(2)) was investigated as an antimicrobial additive to eliminate Listeria monocytogenes. Several experiments were performed using brine solutions made of sodium chloride (NaCl) and calcium chloride (CaCl(2)) inoculated with L. monocytogenes and/or treated with 3 ppm of ClO(2). First, 10 and 20% CaCl(2) and NaCl solutions (pH 7.0) were inoculated with a five-strain cocktail of L. monocytogenes to obtain approximately 7 log CFU/ml and incubated 8 h at 0 degrees C. The results demonstrated that L. monocytogenes survived in 10% CaCl(2), 10 and 20% NaCl, and pure water. L. monocytogenes levels were reduced approximately 1.2 log CFU/ml in 20% CaCl(2). Second, inoculated ( approximately 7 log CFU/ml) brine solutions (10 and 20% NaCl and 10% CaCl(2)) treated with 3 ppm of ClO(2) resulted in a approximately 4-log reduction of the pathogen within 90 s. The same was not observed in a solution of 20% CaCl(2); further investigation demonstrated that high levels of divalent cations interfere with the disinfectant. Spent brine solutions from hot dog and ham chilling were treated with ClO(2) at concentrations of 3 or 30 ppm. At these concentrations, ClO(2) did not reduce L. monocytogenes. Removal of divalent cations and organic material in brine solutions prior to disinfection with ClO(2) should be investigated to improve the efficacy of the compound against L. monocytogenes. The information from this study may be useful to processing establishments and researchers who are investigating antimicrobials in chilling brine solutions.

CARs: Synthetic Immunoreceptors for Cancer Therapy and Beyond

PubMed Central

Chang, ZeNan L.; Chen, Yvonne Y.

2017-01-01

Chimeric antigen receptors (CARs) are versatile synthetic receptors that provide T cells with engineered specificity. Clinical success in treating B-cell malignancies has demonstrated the therapeutic potential of CAR-T cells against cancer, and efforts are underway to expand the use of engineered T cells to the treatment of diverse medical conditions, including infections and autoimmune diseases. Here, we review current understanding of the molecular properties of CARs, how this knowledge informs the rational design and characterization of novel receptors, successes and shortcomings of CAR-T cells in the clinic, and emerging solutions for the continued improvement of CAR-T cell therapy. PMID:28416139

Managing patients with chronic cough: challenges and solutions.

PubMed

Perotin, Jeanne-Marie; Launois, Claire; Dewolf, Maxime; Dumazet, Antoine; Dury, Sandra; Lebargy, François; Dormoy, Valérian; Deslee, Gaëtan

2018-01-01

Chronic cough is a common complaint and a frequent cause of medical consultation. Its management can be difficult. We present here an overview of the current guidelines for the management of chronic cough. Different steps are detailed, including the initial research of an obvious etiology and alert signs that should lead to further investigation of underlying condition. The diagnosis of the most frequent causes: asthma, non-asthmatic eosinophilic bronchitis, gastroesophageal reflux disease and upper airway cough syndrome should be considered, assessed and treated accordingly. Recent advances have been made in the comprehension of refractory chronic cough pathophysiology as well as its pharmacologic and non-pharmacologic treatment, especially speech pathology therapy.

[Peroperative peritoneal lavage and intra-abdominal instillation of antibiotics in an experiment].

PubMed

Batalík, B; Mydlo, J

1991-03-01

The authors present the results of an experiment on dogs where lethal diffuse peritonitis was induced in the standard way and was treated only by peroperative peritoneal lavage during reoperation within 24 hours. In the first group (n = 10) this method alone reduced the mortality despite the adverse prognosis to 70%, after addition of an effective antibiotic and metronidazole into the last lot of the lavage solution in the second equally sized group to 10%. The results prove a marked therapeutic asset of this method which as part of comprehensive treatment of peritonitis improves substantially the final effect also under clinical conditions.

A Deceptively Simple Solution for Refractory Melasma: Glycolic Acid Peels and Hydroquinone at Home

PubMed Central

Oka, Aiko; Osawa, Ema; Koshima, Isao

2017-01-01

Summary: Although various treatment methods for melasma have developed, substantial improvement of the condition is sometimes difficult. We have experientially found that some of refractory melasma caused by daily friction can easily be treated by using a combination of a peeling agent (20% glycolic acid) and a depigmenting agent (5% hydroquinone) twice daily at home. And here, by performing skin biopsies, we revealed the pathological mechanism: hyperkeratosis caused by repeated physical stimulus, which prevents infiltration of topical therapeutic agents, was dramatically reduced by chemical peeling, resulting that the melanin pigments were effectively cleared by topical hydroquinone. PMID:28607861

Hybrid treatment of a huge complex aortic pseudo-aneurysm subsequent to a coarctation.

PubMed

Rizza, Antonio; Barletta, Valentina; Palmieri, Cataldo; Berti, Sergio

2017-07-01

Endovascular treatment of pseudo-aneurysms subsequent to a pre-existing aortic coarctation is becoming a well-accepted technical solution especially in patients presenting anatomical challenges involving the aortic arch. We report the case of a 65-year-old woman with a huge pseudo-aneurysm of the descending thoracic aorta. Diagnostic imaging assessment documented also the presence of an aneurysmatic aberrant right subclavian artery. Due to patient's anatomical arterial condition, we decided to treat the aneurysm applying a hybrid approach. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Experimental measurements of U60 nanocluster stability in aqueous solution

NASA Astrophysics Data System (ADS)

Flynn, Shannon L.; Szymanowski, Jennifer E. S.; Gao, Yunyi; Liu, Tianbo; Burns, Peter C.; Fein, Jeremy B.

2015-05-01

In this study, the aqueous behavior of isolated U60 nanoclusters (K16Li25[UO2(O2)OH]60)-19 was studied under several pH conditions and nanocluster concentrations to determine if the nanoclusters exhibit solid phase buffering behavior or if they exhibit behavior more like aqueous complexes. U60 is a cage cluster consisting of 60 (UO2)(O2)2(OH)2 uranyl polyhedral which share OH and O2 groups with their neighboring uranyl polyhedral, resulting in negatively charged cage clusters whose charge is at least partially offset by K+ and Li+ in the aqueous phase. Batch experiments to monitor nanocluster stability were conducted for 16 days at pH 7.5, 8.0 and 8.5 at nanocluster suspension concentrations of 1.4, 2.8 and 6.0 g/L. The aqueous concentrations of U, Li, and K, determined after 10 kDa molecular weight filtration, achieved steady-state with the nanoclusters within 24 h. The steady-state aqueous U, Li, and K concentrations were independent of solution pH, however they increased with increasing nanocluster concentration, indicating that the nanoclusters do not buffer the aqueous activities as a bulk solid phase would, but exhibit behavior that is more characteristic of dissolved aqueous complexes. The ion activity product (I.A.P.) value was calculated using two approaches: (1) treating the nanoclusters as a solid phase with an activity of one, and (2) treating the nanoclusters as aqueous complexes with a non-unit activity equal to their concentration in solution. The I.A.P. values that were calculated with non-unit activity for the nanoclusters exhibited significantly less variation as a function of nanocluster concentration compared to the I.A.P. values calculated with a nanocluster activity of one. The results yield a calculated log dissociation constant for the U60 nanoclusters of 9.2 + 0.2/-0.3 (1σ). Our findings provide a better understanding of the thermodynamic stability and behavior of U60 nanoclusters in aqueous systems, and can be used to estimate the dissociation behavior of nanoclusters under a range of aqueous conditions.

Geochemical behaviour of palladium in soils and Pd/PdO model substances in the presence of the organic complexing agents L-methionine and citric acid.

PubMed

Zereini, Fathi; Wiseman, Clare L S; Vang, My; Albers, Peter; Schneider, Wolfgang; Schindl, Roland; Leopold, Kerstin

2016-01-01

Risk assessments of platinum group metal (PGE) emissions, notably those of platinum (Pt), palladium (Pd) and rhodium (Rh), have been mostly based on data regarding the metallic forms used in vehicular exhaust converters, known to be virtually biologically inert and immobile. To adequately assess the potential impacts of PGE, however, data on the chemical behaviour of these metals under ambient conditions post-emission is needed. Complexing agents with a high affinity for metals in the environment are hypothesized to contribute to an increased bioaccessibility of PGE. The purpose of this study is to examine the modulating effects of the organic complexing agents, L-methionine and citric acid, on the geochemical behavior of Pd in soils and model substances (Pd black and PdO). Batch experimental tests were conducted with soils and model substances to examine the impacts of the concentration of complexing agents, pH and length of extraction period on Pd solubility and its chemical transformation. Particle surface chemistry was examined using X-ray photoelectron spectroscopy (XPS) on samples treated with solutions under various conditions, including low and high O2 levels. Pd was observed to be more soluble in the presence of organic complexing agents, compared to Pt and Rh. Pd in soils was more readily solubilized with organic complexing agents compared to the model substances. After 7 days of extraction, L-methionine (0.1 M) treated soil and Pd black samples, for instance, had mean soluble Pd fractions of 12.4 ± 5.9% and 0.554 ± 0.024%, respectively. Surface chemistry analyses (XPS) confirmed the oxidation of metallic Pd surfaces when treated with organic complexing agents. The type of organic complexing agent used for experimental purposes was observed to be the most important factor influencing solubility, followed by solution pH and time of extraction. The results demonstrate that metallic Pd can be transformed into more bioaccessible species in the presence of organic complexing agents which are ubiquitous in the environment.

Environment-Friendly Post-Treatment of PEDOT-Tos Films by Aqueous Vitamin C Solutions for Tuning of Thermoelectric Properties

NASA Astrophysics Data System (ADS)

Khan, Ezaz Hasan; Thota, Sammaiah; Wang, Yiwen; Li, Lian; Wilusz, Eugene; Osgood, Richard; Kumar, Jayant

2018-04-01

Aqueous vitamin C solution has been used as an environment-friendly reducing agent for tuning the thermoelectric properties of p-toluenesulfonate-doped poly(3,4-ethylenedioxythiophene) (PEDOT-Tos) films. The de-doping of the PEDOT-Tos films by aqueous vitamin C solutions led to a decrease in the electrical conductivity of the films. The measured ultraviolet-visible-near-infrared and x-ray photoelectron spectra clearly indicated the reduction in the oxidation level from 37 to 23% when the PEDOT-Tos films were treated with 5% (w/v) aqueous vitamin C solutions. An increase in the Seebeck coefficient was measured, resulting in an increase in the figure-of-merit (ZT). A 42% increase in ZT was determined for the 5% aqueous vitamin C solution-treated PEDOT-Tos films with respect to that of the untreated films.

Ca(OH).sub.2 -treated ceramic microsphere

DOEpatents

Sugama, Toshifumi

1989-01-01

Geothermal wells with lost circulation problems are treated with a lightweight, high temperature (i.e. 350.degree. C.) cement slurry which incorporates pressure resistant hollow microspheres into the slurry wherein the spheres have been pretreated with an alkali compound such as Ca(OH).sub.2 for up to 20 hours and at 100.degree.-300.degree. C. Preferably, the alkali solution is a saturated aqueous solution and the treatment is for 10 hours.

Ca(OH).sub.2 -treated ceramic microsphere

DOEpatents

Sugama, Toshifumi

1990-01-01

Geothermal wells with lost circulation problems are treated with a lightweight, high temperature (i.e. 350.degree. C.) cement slurry which incorporates pressure resistant hollow microspheres into the slurry wherein the spheres have been pretreated with an alkali compound such as Ca(OH).sub.2 for up to 20 hours and at 100.degree.-300.degree. C. Preferably, the alkali solution is a saturated aqueous solution and the treatment is for 10 hours.

Non-thermal atmospheric pressure plasma activates lactate in Ringer’s solution for anti-tumor effects

NASA Astrophysics Data System (ADS)

Tanaka, Hiromasa; Nakamura, Kae; Mizuno, Masaaki; Ishikawa, Kenji; Takeda, Keigo; Kajiyama, Hiroaki; Utsumi, Fumi; Kikkawa, Fumitaka; Hori, Masaru

2016-11-01

Non-thermal atmospheric pressure plasma is a novel approach for wound healing, blood coagulation, and cancer therapy. A recent discovery in the field of plasma medicine is that non-thermal atmospheric pressure plasma not only directly but also indirectly affects cells via plasma-treated liquids. This discovery has led to the use of non-thermal atmospheric pressure plasma as a novel chemotherapy. We refer to these plasma-treated liquids as plasma-activated liquids. We chose Ringer’s solutions to produce plasma-activated liquids for clinical applications. In vitro and in vivo experiments demonstrated that plasma-activated Ringer’s lactate solution has anti-tumor effects, but of the four components in Ringer’s lactate solution, only lactate exhibited anti-tumor effects through activation by non-thermal plasma. Nuclear magnetic resonance analyses indicate that plasma irradiation generates acetyl and pyruvic acid-like groups in Ringer’s lactate solution. Overall, these results suggest that plasma-activated Ringer’s lactate solution is promising for chemotherapy.

The Effect of Solution Heat Treatment on an Advanced Nickel-Base Disk Alloy

NASA Technical Reports Server (NTRS)

Gayda, J.; Gabb, T. P.; Kantzos, P. T.

2004-01-01

Five heat treat options for an advanced nickel-base disk alloy, LSHR, have been investigated. These included two conventional solution heat treat cycles, subsolvus/oil quench and supersolvus/fan cool, which yield fine grain and coarse grain microstructure disks respectively, as well as three advanced dual microstructure heat treat (DMHT) options. The DMHT options produce disks with a fine grain bore and a coarse grain rim. Based on an overall evaluation of the mechanical property data, it was evident that the three DMHT options achieved a desirable balance of properties in comparison to the conventional solution heat treatments for the LSHR alloy. However, one of the DMHT options, SUB/DMHT, produced the best set of properties, largely based on dwell crack growth data. Further evaluation of the SUB/DMHT option in spin pit experiments on a generic disk shape demonstrated the advantages and reliability of a dual grain structure at the component level.

Numerical Solution of the Radiative Transfer Equation: X-Ray Spectral Formation from Cylindrical Accretion onto a Magnetized Neutron Star

NASA Technical Reports Server (NTRS)

Fairnelli, R.; Ceccobello, C.; Romano, P.; Titarchuk, L.

2011-01-01

Predicting the emerging X-ray spectra in several astrophysical objects is of great importance, in particular when the observational data are compared with theoretical models. This requires developing numerical routines for the solution of the radiative transfer equation according to the expected physical conditions of the systems under study. Aims. We have developed an algorithm solving the radiative transfer equation in the Fokker-Planck approximation when both thermal and bulk Comptonization take place. The algorithm is essentially a relaxation method, where stable solutions are obtained when the system has reached its steady-state equilibrium. Methods. We obtained the solution of the radiative transfer equation in the two-dimensional domain defined by the photon energy E and optical depth of the system pi using finite-differences for the partial derivatives, and imposing specific boundary conditions for the solutions. We treated the case of cylindrical accretion onto a magnetized neutron star. Results. We considered a blackbody seed spectrum of photons with exponential distribution across the accretion column and for an accretion where the velocity reaches its maximum at the stellar surface and at the top of the accretion column, respectively. In both cases higher values of the electron temperature and of the optical depth pi produce flatter and harder spectra. Other parameters contributing to the spectral formation are the steepness of the vertical velocity profile, the albedo at the star surface, and the radius of the accretion column. The latter parameter modifies the emerging spectra in a specular way for the two assumed accretion profiles. Conclusions. The algorithm has been implemented in the XPEC package for X-ray fitting and is specifically dedicated to the physical framework of accretion at the polar cap of a neutron star with a high magnetic field (approx > 10(exp 12) G). This latter case is expected to be of typical accreting systems such as X-ray pulsars and supergiant fast X ray transients.

Modified Mixed Lagrangian-Eulerian Method Based on Numerical Framework of MT3DMS on Cauchy Boundary.

PubMed

Suk, Heejun

2016-07-01

MT3DMS, a modular three-dimensional multispecies transport model, has long been a popular model in the groundwater field for simulating solute transport in the saturated zone. However, the method of characteristics (MOC), modified MOC (MMOC), and hybrid MOC (HMOC) included in MT3DMS did not treat Cauchy boundary conditions in a straightforward or rigorous manner, from a mathematical point of view. The MOC, MMOC, and HMOC regard the Cauchy boundary as a source condition. For the source, MOC, MMOC, and HMOC calculate the Lagrangian concentration by setting it equal to the cell concentration at an old time level. However, the above calculation is an approximate method because it does not involve backward tracking in MMOC and HMOC or allow performing forward tracking at the source cell in MOC. To circumvent this problem, a new scheme is proposed that avoids direct calculation of the Lagrangian concentration on the Cauchy boundary. The proposed method combines the numerical formulations of two different schemes, the finite element method (FEM) and the Eulerian-Lagrangian method (ELM), into one global matrix equation. This study demonstrates the limitation of all MT3DMS schemes, including MOC, MMOC, HMOC, and a third-order total-variation-diminishing (TVD) scheme under Cauchy boundary conditions. By contrast, the proposed method always shows good agreement with the exact solution, regardless of the flow conditions. Finally, the successful application of the proposed method sheds light on the possible flexibility and capability of the MT3DMS to deal with the mass transport problems of all flow regimes. © 2016, National Ground Water Association.

An Onsager Singularity Theorem for Turbulent Solutions of Compressible Euler Equations

NASA Astrophysics Data System (ADS)

Drivas, Theodore D.; Eyink, Gregory L.

2017-12-01

We prove that bounded weak solutions of the compressible Euler equations will conserve thermodynamic entropy unless the solution fields have sufficiently low space-time Besov regularity. A quantity measuring kinetic energy cascade will also vanish for such Euler solutions, unless the same singularity conditions are satisfied. It is shown furthermore that strong limits of solutions of compressible Navier-Stokes equations that are bounded and exhibit anomalous dissipation are weak Euler solutions. These inviscid limit solutions have non-negative anomalous entropy production and kinetic energy dissipation, with both vanishing when solutions are above the critical degree of Besov regularity. Stationary, planar shocks in Euclidean space with an ideal-gas equation of state provide simple examples that satisfy the conditions of our theorems and which demonstrate sharpness of our L 3-based conditions. These conditions involve space-time Besov regularity, but we show that they are satisfied by Euler solutions that possess similar space regularity uniformly in time.

Process for desulfurizing petroleum feedstocks

DOEpatents

Gordon, John Howard; Alvare, Javier

2014-06-10

A process for upgrading an oil feedstock includes reacting the oil feedstock with a quantity of an alkali metal, wherein the reaction produces solid materials and liquid materials. The solid materials are separated from the liquid materials. The solid materials may be washed and heat treated by heating the materials to a temperature above 400.degree. C. The heat treating occurs in an atmosphere that has low oxygen and water content. Once heat treated, the solid materials are added to a solution comprising a polar solvent, where sulfide, hydrogen sulfide or polysulfide anions dissolve. The solution comprising polar solvent is then added to an electrolytic cell, which during operation, produces alkali metal and sulfur.

In situ retreival of contaminants or other substances using a barrier system and leaching solutions and components, processes and methods relating thereto

DOEpatents

Nickelson, Reva A.; Walsh, Stephanie; Richardson, John G.; Dick, John R.; Sloan, Paul A.

2005-06-28

Processes and methods relating to treating contaminants and collecting desired substances from a zone of interest using subterranean collection and containment barriers. Tubular casings having interlock structures are used to create subterranean barriers for containing and treating buried waste and its effluents. The subterranean barrier includes an effluent collection system. Treatment solutions provided to the zone of interest pass therethrough and are collected by the barrier and treated or recovered, allowing on-site remediation. Barrier components may be used to in the treatment by collecting or removing contaminants or other materials from the zone of interest.

Method of in situ retrieval of contaminants or other substances using a barrier system and leaching solutions

DOEpatents

Nickelson, Reva A.; Walsh, Stephanie; Richardson, John G.; Dick, John R.; Sloan, Paul A.

2006-12-26

Processes and methods relating to treating contaminants and collecting desired substances from a zone of interest using subterranean collection and containment barriers. Tubular casings having interlock structures are used to create subterranean barriers for containing and treating buried waste and its effluents. The subterranean barrier includes an effluent collection system. Treatment solutions provided to the zone of interest pass therethrough and are collected by the barrier and treated or recovered, allowing on-site remediation. Barrier components may be used to in the treatment by collecting or removing contaminants or other materials from the zone of interest.

A new relativistic stellar model with anisotropic fluid in Karmarkar space-time

NASA Astrophysics Data System (ADS)

Singh, Ksh. Newton; Pant, Neeraj; Troconis, O.

2017-02-01

We are presenting a new class of well-behaved solutions in embedding class-I. We proceed our calculations by assuming a new type of grr metric potential and solved for the other metric gtt using Karmarkar condition. The necessary condition that any solutions of Einstein's field equations to be class-I is to satisfy Karmarkar condition and sufficient condition is to satisfy Pandey-Sharma condition i.e. R2323 ≠ 0. The solution also satisfies strong energy condition, null energy condition, dominant energy condition and weak energy condition. The obtained compactness parameter is within Buchdahl limit i.e. 2 M / R ≤ 8 / 9. The solution also satisfies the causality condition and can represent stable stellar fluid system as the adiabatic index Γ > 4 / 3 and the stability factor holds - 1 ≤ vt2- vr2 ≤ 0 good. Finally, we have tuned our solution for two compact stars PSR J1614-2230 and 4U1608-52 which are well-behaved in all respects.

Application of acidic treated pumice as an adsorbent for the removal of azo dye from aqueous solutions: kinetic, equilibrium and thermodynamic studies

PubMed Central

2012-01-01

Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal of AR14 and AR18 followed Freundlich (r2>0.99) and Langmuir (r2>0.99) isotherm models. Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r2>0.99) and intra-particle diffusion (r2>0.98) models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer. Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89% regeneration for AR14 and AR18, respectively. PMID:23369579

Heat and pH stability of alkali-extractable corn arabinoxylan and its xylanase-hydrolyzate and their viscosity behavior.

PubMed

Rumpagaporn, Pinthip; Kaur, Amandeep; Campanella, Osvaldo H; Patterson, John A; Hamaker, Bruce R

2012-01-01

In in vitro batch fermentations, both alkali-extractable corn arabinoxylan (CAX) and its xylanase-hydrolyzate (CH) were utilized by human fecal microbiota and produced similar short chain fatty acid (SCFA) contents and desirable long fermentation profiles with low initial gas production. Fortification of these arabinoxylans into processed foods would contribute desirable dietary fiber benefits to humans. Heat and pH stability, as well as viscosity behavior of CAX and CH were investigated. Size exclusion chromatography was used to analyze the molecular size distribution after treatment at different pH's and heating temperatures for different time periods. Treated under boiling and pressure cooking conditions at pH 3, CAX was degraded to a smaller molecular size, whereas the molecular size of the CH showed only a minor decrease. CAX and CH were mostly stable at neutral pH, except when CAX was treated under pressure for 60 min that slightly lowered molecular size. At 37 °C, neither CAX nor CH was adversely affected by treatment at low or neutral pH. The viscosities of solutions containing 5% and 10% of CAX were 48.7 and 637.0 mPa.s, respectively that were higher than those of solutions containing 5% and 10% of its hydrolyzate at shear rate 1 s⁻¹. The CAX solutions showed Newtonian flow behavior, whereas shear-thinning behavior was observed in CH solutions. In conclusion, the hydrolyzate of CAX has potential to be used in high fiber drinks due to its favorable fermentation properties, higher pH and heat stability, lower and shear-thinning viscosity, and lighter color than the native CAX. Arabinoxylan extracted by an alkali from corn bran is a soluble fiber with a desirable low initial and extended fermentation property. Corn arabinoxylan hydrolyzate using an endoxylanase was much more stable at different levels of acidity and heat than the native arabinoxylan, and showed lower solution viscosity and shear-thinning property that indicates its potential as an alternative functional dietary fiber for the beverage industry. © 2011 Institute of Food Technologists®

Auditory function after application of ototopical vancomycin and mupirocin solutions in a murine model.

PubMed

Rutherford, Kimberley D; Kavanagh, Katherine; Parham, Kourosh

2011-03-01

To determine whether mupirocin (440 µg/mL) and vancomycin otic drops (25 mg/mL) show evidence of ototoxicity in CBA/J mice immediately following a 7-day course of daily intratympanic (IT) injections and 1 month following treatment. Nonrandomized controlled trial. Academic hospital laboratory. Twenty CBA/J mice. Mean auditory brainstem response (ABR) thresholds increased in all drug- and saline-treated ears immediately after 7 days of IT injections but returned to baseline for most stimulus frequencies by 30 days later. This finding appeared to be correlated with the presence and subsequent resolution of tympanic membrane (TM) perforations and granulation tissue at the injection sites. Mupirocin-treated ears showed no significant difference in ABR thresholds compared to saline-treated ears. No significant differences were noted between vancomycin- and saline-treated ears, but there was a significant interaction between testing day and stimulus frequency (P < .001). Further analysis revealed that ABR thresholds at 32 kHz remained significantly elevated in vancomycin-treated mice despite the resolution of TM perforations and granulation tissue 30 days after completion of IT injections (95% confidence interval, -13.5 to -5.5, P < .01). Although IT application of mupirocin solution (440 µg/mL) caused no significant change in the ABR thresholds in a murine model, vancomycin solution (25 mg/mL) resulted in high-frequency threshold elevations in both the ear directly injected and the contralateral ear. Mupirocin solution may be beneficial in managing otitis externa and media caused by resistant pathogens. Further studies of ototopical vancomycin are needed to define parameters governing its safe use.

Estimation of osmotic parameters accompanying zeatin-induced growth of detached cucumber cotyledons.

PubMed

Rayle, D L; Ross, C W; Robinson, N

1982-12-01

Water potential (psi), the osmotic potential (psi(pi)), and the pressure potential (psi(p)) of detached cotyledons isolated from Cucumis sativus L. cv Marketer seedlings after 0, 1.5, and 3 days growth with and without zeatin were determined. From zero time to 3 days, cotyledons incubated without exogenous zeatin exhibited a slight decrease in psi (from -0.4 to -1.0 bars), while those grown with zeatin developed even more negative values (about -4 bars). Both groups showed rising psi(pi) values (decreases in solutes per unit volume), but this rise was more dramatic in those treated with zeatin. These data indicate that the capacity of zeatin-treated cotyledons to take up water more rapidly than controls and thus expand faster must be due to wall loosening, as reflected in psi(p) values which declined during 3 days from about +11 bars to about +1.4 bars.It was also found that freshly detached cotyledons or those grown without exogenous zeatin exhibited osmoregulation in polyethylene glycol (PEG) solutions. That is, while cotyledons initially lost H(2)O into certain PEG solutions, their psi values decreased over time and they began absorbing water after 1 to 4 hours. After 3 days growth, zeatin-treated cotyledons had lost most of this capacity of osmoregulate. It seems likely that osmoregulation in cotyledons not treated with zeatin is due to wall loosening rather than changes in psi(pi). Zeatin-treated cotyledons with already loosened walls may not have this option to deal with water stress and thus simply come to equilibrium with external PEG solutions.

Textile Dye Removal from Aqueous Solution using Modified Graphite Waste/Lanthanum/Chitosan Composite

NASA Astrophysics Data System (ADS)

Kusrini, E.; Wicaksono, B.; Yulizar, Y.; Prasetyanto, EA; Gunawan, C.

2018-03-01

We investigated various pre-treatment processes of graphite waste using thermal, mechanical and chemical methods. The aim of this work is to study the performance of modified graphite waste/lanthanum/chitosan composite (MG) as adsorbent for textile dye removal from aqueous solution. Effect of graphite waste resources, adsorbent size and lanthanum concentration on the dye removal were studied in batch experiments. Selectivity of MG was also investigated. Pre-heated graphite waste (NMG) was conducted at 80°C for 1 h, followed by mechanical crushing of the resultant graphite to 75 μm particle size, giving adsorption performance of ˜58%, ˜67%, ˜93% and ˜98% of the model dye rhodamine B (concentration determined by UV-vis spectroscopy at 554 nm), methyl orange (464 nm), methylene blue (664 nm) and methyl violet (580 nm), respectively from aqueous solution. For this process, the system required less than ˜5 min for adsorbent material to be completely saturated with the adsorbate. Further chemical modification of the pre-treated graphite waste (MG) with lanthanum (0.01 – V 0.03 M) and chitosan (0.5% w/w) did not improve the performance of dye adsorption. Under comparable experimental conditions, as those of the ‘thermal-mechanical-pre-treated-only’ (NMG), modification of graphite waste (MG) with 0.03 M lanthanum and 0.5% w/w chitosan resulted in ˜14%, ˜47%, ˜72% and ˜85% adsorption of rhodamine B, methyl orange, methylene blue and methyl violet, respectively. Selective adsorption of methylene blue at most to ˜79%, followed by methyl orange, methyl violet and rhodamine B with adsorption efficiency ˜67, ˜38, and ˜9% sequentially using MG with 0.03 M lanthanum and 0.5% w/w chitosan.

Sodium hypochlorite oxidation of petroleum aliphatic contaminants in calcareous soils.

PubMed

Picard, François; Chaouki, Jamal

2016-02-01

This research project investigated the sodium hypochlorite (NaClO) oxidation of aliphatic petroleum contaminants (C10-C50) in a calcareous soil (average 5473 ppm C10-C50, 15 wt% Ca), which had been excavated from a contaminated industrial site. The decontamination objective was to lower the C10-C50 concentration to 700 ppm. CO2 acidity was used in the project to boost the NaClO oxidation yield and seems to have played a role in desorbing the natural organic matter. The experimental conditions were a 2- to 16-h reaction time, at room temperature, with a 1 to 12.5 wt% NaClO oxidative solution and a fixed 2:1 solution-to-soil ratio. With a 3 wt% NaClO solution and with a CO2 overhead, the NaClO dosage requirement was maintained below 60 g NaClO/g of oxidized C10-C50 over the entire decontamination range. The strong chlorine smell remaining after the reaction was completed suggests that part of the NaClO requirement can be recycled. Except traces of chloroform, there were no regulation-listed organochloride contaminants detected on either the treated soil samples or leachates and the total count of chlorinated compounds in treated soil samples was below the detection limit of 250 mg/kg. The NaClO oxidation mechanism on aliphatic substrates might be triggered by transition metals, such as manganese, but no attempt has been made to investigate the oxidation mechanism. Further investigations would include a constant-fed NaClO system and other techniques to lower the required NaClO dosage. Copyright © 2015 Elsevier Ltd. All rights reserved.

The improvement of adhesive properties of PEEK through different pre-treatments

NASA Astrophysics Data System (ADS)

Hallmann, Lubica; Mehl, Albert; Sereno, Nuno; Hämmerle, Christoph H. F.

2012-07-01

The purpose of this in vitro study was the evaluation of the bond strength of the adhesives/composite resin to Poly Ether Ether Ketone (PEEK) based dental polymer after using different surface conditioning methods. PEEK blanks were cut into discs. All disc specimens were polished with 800 grit SiC paper and divided into 6 main groups. Main groups were divided into 2 subgroups. The main groups of 32 specimens each were treated as follow: (1) control specimens (no treatment), (2) piranha solution etching, (3) abraded with 50 μm alumina particles and chemical etching, (4) abraded with 110 μm alumina particles and chemical etching, (5) abraded with 30 μm silica-coated alumina particles and chemical etching, (6) abraded with 110 μm silica-coated alumina particles and chemical etching. Plexiglas tubes filled with a composite resin (RelyX Unicem) were bonded to the specimens. The adhesives used were Heliobond and Clearfil Ceramic Primer. Each specimen was stored in distilled water (37 °C) for 3 days. Tensile bond strength was measured in a universal testing machine and failure methods were evaluated. Abraded surface with 50 μm alumina particles followed by etching with piranha solution lead to the highest bond strength of 21.4 MPa when Heliobond like adhesive was used. Tribochemical silica coated/etched PEEK surfaces did not have an effect on the bond strength. Non-treated PEEK surface was not able to establish a bond with composite resin. The proper choice of adhesive/composite resin system leads to a strong bond. ConclusionAirborne particle abrasion in combination with piranha solution etching improves the adhesive properties of PEEK.

Efficacy and safety of imidacloprid/moxidectin spot-on solution and fenbendazole in the treatment of dogs naturally infected with Angiostrongylus vasorum (Baillet, 1866).

PubMed

Willesen, J L; Kristensen, A T; Jensen, A L; Heine, J; Koch, J

2007-07-20

A randomized, blinded, controlled multicentre field trial study was conducted to evaluate the efficacy and safety of imidacloprid 10%/moxidectin 2.5% spot-on solution and fenbendazole in treating dogs naturally infected with Angiostrongylus vasorum. Dogs were randomly treated either with a single dose of 0.1 ml/kg bodyweight of imidacloprid 10%/moxidectin 2.5% spot-on solution or with 25 mg/kg bodyweight fenbendazole per os for 20 days. The study period was 42 days with dogs being examined on days 0, 7 and 42. The primary efficacy parameter was the presence of L1 larvae in faecal samples evaluated by a Baermann test from three consecutive days. Thoracic radiographs performed on each visit were being taken as a paraclinical parameter to support the results of the Baermann test. Twenty-seven dogs in the imidacloprid/moxidectin group and 23 dogs in the fenbendazole group completed the study according to protocol. The efficacies of the two treatment protocols were 85.2% (imidacloprid/moxidectin) and 91.3% (fenbendazole) with no significant difference between treatment groups. On radiographic evaluation pulmonary parenchyma showed similar improvement in each group. No serious adverse effects to treatment were recorded: most of the minor adverse effects were gastrointestinal such as diarrhea (nine dogs), vomitus (eight dogs) and salivation (three dogs). In general, these adverse effects were of short duration (1-2 days) within the first few days after treatment start and required little or no treatment. This prospective study demonstrates that both treatment protocols used are efficacious under field conditions, that treatment of mildly to moderately infected dogs with either of these protocols is safe and yields an excellent prognosis for recovering from the infection.

Comparison of Corneal Riboflavin Gradients Using Dextran and HPMC Solutions.

PubMed

Ehmke, Tobias; Seiler, Theo G; Fischinger, Isaak; Ripken, Tammo; Heisterkamp, Alexander; Frueh, Beatrice E

2016-12-01

To determine the riboflavin concentration gradient in the anterior corneal stroma when using hydroxypropyl methylcellulose (HPMC) or dextran as the carrier agent. Four different groups of porcine corneas (5 each) were compared regarding the riboflavin concentration in the anterior stroma. Prior to all experiments, stable hydration conditions were established for the corresponding solution. The dextran groups were treated with 0.1% riboflavin in 20% dextran for 10 and 30 minutes and the HPMC groups with 0.1% riboflavin in 1.1% HPMC for 10 and 30 minutes. After imbibition, nonlinear microscopy and consecutive image analysis were used to determine two-photon fluorescence intensities. To determine the riboflavin concentration, corneas were saturated and measured a second time by two-photon microscopy. With this measurement, a proper correction for absorption and scattering could be performed. Ultraviolet-A (UVA) transmission was measured after the application time for each group. Riboflavin concentration decreased with increasing depth and increased with longer application times in all groups. Comparing the dextran for 30 minutes and HPMC for 10 minutes groups, a significantly higher stromal riboflavin concentration was found within the most anterior 70 µm in the dextran group for 30 minutes, whereas deeper than 260 µm HPMC-assisted imbibition for 10 minutes yielded higher concentrations. In dextran-treated corneas, values obtained from pachymetry were substantially reduced, whereas HPMC-assisted imbibition led to a decent swelling. UVA transmission values were higher in dextran-assisted imbibition than in HPMC-assisted imbibition. Stromal riboflavin gradients are similar when applied in dextran for 30 minutes and HPMC for 10 minutes. When using HPMC solutions, a shallower cross-linked volume is expected due to a higher corneal hydration. [J Refract Surg. 2016;32(12):798-802.]. Copyright 2016, SLACK Incorporated.

Vaccination refusal. Autonomy and permitted coercion.

PubMed

Grzybowski, Andrzej; Patryn, Rafał K; Sak, Jarosław; Zagaja, Anna

2017-06-01

The article presents vaccination obligation in relation to the existing or newly enacted legislation. Mass vaccinations and a wave of criticism they cause, forces us to reflect on the limits of medical intervention in the human body and the boundaries granted to individual's freedom and autonomy. This problem is universal and exists mainly in countries without mandatory vaccinations. Analyzing recent years, it must be underlined that a process in some legislatures has been introduced to enforce various forms of vaccination coercion. Although, refusing vaccinations has been treated liberally, the last wave of epidemics in the United States and Europe forced the creation of a different approach. Gradually in the USA, a duty (not a 'coercion') of vaccination is being enforced. Occurring epidemics, (e.g. measles) and dangers resulting from them, force authorities to violate the principle of autonomy and restrict individuals' freedoms regarding their own body. The article presents legal solutions relating to vaccinations in the United States and Europe i.e. administrative decisions imposing vaccinations, solutions conditioning social existence and financial penalties for not complying with this obligation and proposes a solution based on financial liability that will balance out patients' autonomy and public security.

Dynamic Conformations of Nucleosome Arrays in Solution from Small-Angle X-ray Scattering

NASA Astrophysics Data System (ADS)

Howell, Steven C.

Chromatin conformation and dynamics remains unsolved despite the critical role of the chromatin in fundamental genetic functions such as transcription, replication, and repair. At the molecular level, chromatin can be viewed as a linear array of nucleosomes, each consisting of 147 base pairs (bp) of double-stranded DNA (dsDNA) wrapped around a protein core and connected by 10 to 90 bp of linker dsDNA. Using small-angle X-ray scattering (SAXS), we investigated how the conformations of model nucleosome arrays in solution are modulated by ionic condition as well as the effect of linker histone proteins. To facilitate ensemble modeling of these SAXS measurements, we developed a simulation method that treats coarse-grained DNA as a Markov chain, then explores possible DNA conformations using Metropolis Monte Carlo (MC) sampling. This algorithm extends the functionality of SASSIE, a program used to model intrinsically disordered biological molecules, adding to the previous methods for simulating protein, carbohydrates, and single-stranded DNA. Our SAXS measurements of various nucleosome arrays together with the MC generated models provide valuable solution structure information identifying specific differences from the structure of crystallized arrays.

Vaccination refusal. Autonomy and permitted coercion

PubMed Central

Grzybowski, Andrzej; Patryn, Rafał K.; Sak, Jarosław

2017-01-01

The article presents vaccination obligation in relation to the existing or newly enacted legislation. Mass vaccinations and a wave of criticism they cause, forces us to reflect on the limits of medical intervention in the human body and the boundaries granted to individual’s freedom and autonomy. This problem is universal and exists mainly in countries without mandatory vaccinations. Analyzing recent years, it must be underlined that a process in some legislatures has been introduced to enforce various forms of vaccination coercion. Although, refusing vaccinations has been treated liberally, the last wave of epidemics in the United States and Europe forced the creation of a different approach. Gradually in the USA, a duty (not a ‘coercion’) of vaccination is being enforced. Occurring epidemics, (e.g. measles) and dangers resulting from them, force authorities to violate the principle of autonomy and restrict individuals’ freedoms regarding their own body. The article presents legal solutions relating to vaccinations in the United States and Europe i.e. administrative decisions imposing vaccinations, solutions conditioning social existence and financial penalties for not complying with this obligation and proposes a solution based on financial liability that will balance out patients’ autonomy and public security. PMID:28486849

Comparison of arsenic uptake ability of barnyard grass and rice species for arsenic phytoremediation.

PubMed

Sultana, Razia; Kobayashi, Katsuichiro; Kim, Ki-Hyun

2015-01-01

In this research, the relative performance in arsenic (As) remediation was evaluated among some barnyard grass and rice species under hydroponic conditions. To this end, four barnyard grass varieties and two rice species were selected and tested for their remediation potential of arsenic. The plants were grown for 2 weeks in As-rich solutions up to 10 mg As L(-1) to measure their tolerance to As and their uptake capabilities. Among the varieties of plants tested in all treatment types, BR-29 rice absorbed the highest amount of As in the root, while Nipponbare translocated the maximum amount of As in the shoot. Himetainubie barnyard grass produced the highest biomass, irrespective of the quantity of As in the solution. In all As-treated solutions, the maximum uptake of As was found in BR-29 followed by Choto shama and Himetainubie. In contrast, while the bioaccumulation factor was found to be the highest in Nipponbare followed by BR-29 and Himetainubie. The results suggest that both Choto shama and Himetainubie barnyard grass varieties should exhibit a great potential for As removal, while BR-29 and Nipponbare rice species are the best option for arsenic phytoremediation.

Fabrication of doped TiO2 nanotube array films with enhanced photo-catalytic activity

NASA Astrophysics Data System (ADS)

Peighambardoust, Naeimeh-Sadat; Khameneh-asl, Shahin; Khademi, Adib

2018-01-01

In the present work, we investigate the N and Fe-doped TiO2 nanotube array film prepared by treating TiO2 nanotube array film with ammonia solution and anodizing in Fe(NO3)3 solution respectively. This method avoided the use of hazardous ammonia gas, or laborious ion implantation process. N and Fe-doped TiO2 nanotube arrays (TiO2 NTs) were prepared by electrochemical anodization process in 0.5 wt % HF aqueous solution. The anodization was performed at the conditions of 20 V and 20 min, Followed by a wet immersion in NH3.H2O (1M) for N-doping for 2 hr and annealing post-treatment at 450 °C. The morphology and structure of the nanotube films were characterized by field emission scanning electron microscope (FESEM) and EDX. UV-vis. illumination test were done to observe photo-enhanced catalysis. The effect of different annealing temperature on the structure and photo-absorption property of the TiO2-TNTs was investigated. The results showed that N-TNTs nanotubes exhibited higher photocatalytic activity compared whit the Fe-doped and pure TNTs, because doping N promoted the separation of the photogenerated electrons and holes.

Energy demand hourly simulations and energy saving strategies in greenhouses for the Mediterranean climate

NASA Astrophysics Data System (ADS)

Priarone, A.; Fossa, M.; Paietta, E.; Rolando, D.

2017-01-01

This research has been devoted to the selection of the most favourable plant solutions for ventilation, heating and cooling, thermo-hygrometric control of a greenhouse, in the framework of the energy saving and the environmental protection. The identified plant solutions include shading of glazing surfaces, natural ventilation by means of controlled opening windows, forced convection of external air and forced convection of air treated by the HVAC system for both heating and cooling. The selected solution combines HVAC system to a Ground Coupled Heat Pump (GCHP), which is an innovative renewable technology applied to greenhouse buildings. The energy demand and thermal loads of the greenhouse to fulfil the requested internal design conditions have been evaluated through an hourly numerical simulation, using the Energy Plus (E-plus) software. The overall heat balance of the greenhouse also includes the latent heat exchange due to crop evapotranspiration, accounted through an original iterative calculation procedure that combines the E-plus dynamic simulations and the FAO Penman-Monteith method. The obtained hourly thermal loads have been used to size the borehole field for the geothermal heat pump by using a dedicated GCHP hourly simulation tool.

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.

Toxicity of copper sulfate and rotenone to Chinese mystery snail (Bellamya chinensis)

USGS Publications Warehouse

Haak, Danielle M.; Stephen, Bruce J.; Kill, Robert A.; Smeenk, Nicholas A.; Allen, Craig R.; Pope, Kevin L.

2014-01-01

The Chinese mystery snail (Bellamya chinensis) is a freshwater snail native to Southeast Asia, Japan, and Russia and is currently classified as an invasive species in at least 27 states in the USA. The species tolerates a wide range of environmental conditions, making management of established populations difficult. We tested the efficacy of two traditional chemical treatments, rotenone and copper sulfate, on the elimination of adult Chinese mystery snails in laboratory experiments. All snails (N=50) survived 72-hour exposure to rotenone-treated lake water, and 96% (N=25) survived 72-hour exposure to pre-determined rotenone concentrations of 0.25, 2.5, and 25.0 mg/L. All snails (N=10) survived exposure to 1.25 mg/L copper sulfate solution, 90% (N=10) survived exposure to 2.50 mg/L copper sulfate solution, and 80% (N=5) survived exposure to 5.0 mg/L copper sulfate solution. Neither rotenone nor copper sulfate effectively killed adult Chinese mystery snails in laboratory experiments, most likely due to their relatively large size, thick shell, and operculum. Therefore, it appears that populations will be very difficult to control once established, and management should focus on preventing additional spread or introductions of this species.

GroPBS: Fast Solver for Implicit Electrostatics of Biomolecules

PubMed Central

Bertelshofer, Franziska; Sun, Liping; Greiner, Günther; Böckmann, Rainer A.

2015-01-01

Knowledge about the electrostatic potential on the surface of biomolecules or biomembranes under physiological conditions is an important step in the attempt to characterize the physico-chemical properties of these molecules and, in particular, also their interactions with each other. Additionally, knowledge about solution electrostatics may also guide the design of molecules with specified properties. However, explicit water models come at a high computational cost, rendering them unsuitable for large design studies or for docking purposes. Implicit models with the water phase treated as a continuum require the numerical solution of the Poisson–Boltzmann equation (PBE). Here, we present a new flexible program for the numerical solution of the PBE, allowing for different geometries, and the explicit and implicit inclusion of membranes. It involves a discretization of space and the computation of the molecular surface. The PBE is solved using finite differences, the resulting set of equations is solved using a Gauss–Seidel method. It is shown for the example of the sucrose transporter ScrY that the implicit inclusion of a surrounding membrane has a strong effect also on the electrostatics within the pore region and, thus, needs to be carefully considered, e.g., in design studies on membrane proteins. PMID:26636074

Surface modification and properties of Bombyx mori silk fibroin films by antimicrobial peptide

NASA Astrophysics Data System (ADS)

Bai, Liqiang; Zhu, Liangjun; Min, Sijia; Liu, Lin; Cai, Yurong; Yao, Juming

2008-03-01

The Bombyx mori silk fibroin films (SFFs) were modified by a Cecropin B ( CB) antimicrobial peptide, (NH 2)-NGIVKAGPAIAVLGEAAL-CONH 2, using the carbodiimide chemistry method. In order to avoid the dissolution of films during the modification procedure, the SFFs were first treated with 60% (v/v) ethanol aqueous solution, resulting a structural transition from unstable silk I to silk II. The investigation of modification conditions showed that the surface-modified SFFs had the satisfied antimicrobial activity and durability when they were activated by EDC·HCl/NHS solution followed by a treatment in CB peptide/PBS buffer (pH 6.5 or 8) solution at ambient temperature for 2 h. Moreover, the surface-modified SFFs showed the smaller contact angle due to the hydrophilic antimicrobial peptides coupled on the film surface, which is essential for the cell adhesion and proliferation. AFM results indicated that the surface roughness of SFFs was considerably increased after the modification by the peptides. The elemental composition analysis results also suggested that the peptides were tightly coupled to the surface of SFFs. This approach may provide a new option to engineer the surface-modified implanted materials preventing the biomaterial-centered infection (BCI).

Detoxification of zearalenone and ochratoxin A by ozone and quality evaluation of ozonised corn.

PubMed

Qi, Lijun; Li, Yulin; Luo, Xiaohu; Wang, Ren; Zheng, Ruihang; Wang, Li; Li, Yongfu; Yang, Dan; Fang, Wenmiao; Chen, Zhengxing

2016-11-01

Zearalenone (ZEN) and ochratoxin A (OTA) are secondary toxic metabolites of fungi that can contaminate a wide range of food and feedstuff. In this study, the effects of ozone treatment on ZEN and OTA and the quality of ozonised corn are investigated. Ozone significantly affects ZEN and OTA solutions. ZEN was undetectable 5 s after being treated with 10 mg l -1 ozone. However, OTA was resistant to ozonation with a degradation rate of 65.4% after 120 s of treatment. Moreover, ZEN and OTA solutions were difficult to degrade after being dried by a nitrogen stream. Results showed that ozone effectively degraded ZEN and OTA in corn. The degradation rates of ZEN and OTA in corn increased with ozone concentration and treatment time. The degradation of ZEN and OTA at different ozone concentrations appropriately conformed to first-order kinetics with an R 2 value > 0.8749. Furthermore, under the same conditions, corn with increased moisture content (MC) (19.6%) was more sensitive to ozone than corn with a low MC (14.1%). When treated with 100 mg l -1 ozone for 180 min, ZEN and OTA in corn with 19.6% MC decreased by 90.7% and 70.7%, respectively. To evaluate the quality of ozonised corn, subsequent quality experiments were conducted using corn samples treated at different times with 100 mg l -1 ozone. The MC of corn decreased after ozone treatment. The whiteness and yellowness of the corn increased and decreased with increasing time, respectively. The fatty acid value of the corn increased significantly (p ≤ 0.05) after 180 min of treatment. This study verified that ozone can effectively degrade ZEN and OTA in corn, but slightly affected corn quality.

Carnosine retards tumor growth in vivo in an NIH3T3-HER2/neu mouse model.

PubMed

Renner, Christof; Zemitzsch, Nadine; Fuchs, Beate; Geiger, Kathrin D; Hermes, Matthias; Hengstler, Jan; Gebhardt, Rolf; Meixensberger, Jürgen; Gaunitz, Frank

2010-01-06

It was previously demonstrated that the dipeptide carnosine inhibits growth of cultured cells isolated from patients with malignant glioma. In the present work we investigated whether carnosine also affects tumor growth in vivo and may therefore be considered for human cancer therapy. A mouse model was used to investigate whether tumor growth in vivo can be inhibited by carnosine. Therefore, NIH3T3 fibroblasts, conditionally expressing the human epidermal growth factor receptor 2 (HER2/neu), were implanted into the dorsal skin of nude mice, and tumor growth in treated animals was compared to control mice. In two independent experiments nude mice that received tumor cells received a daily intra peritoneal injection of 500 microl of 1 M carnosine solution. Measurable tumors were detected 12 days after injection. Aggressive tumor growth in control animals, that received a daily intra peritoneal injection of NaCl solution started at day 16 whereas aggressive growth in mice treated with carnosine was delayed, starting around day 19. A significant effect of carnosine on tumor growth was observed up to day 24. Although carnosine was not able to completely prevent tumor growth, a microscopic examination of tumors revealed that those from carnosine treated animals had a significant lower number of mitosis (p < 0.0003) than untreated animals, confirming that carnosine affects proliferation in vivo. As a naturally occurring substance with a high potential to inhibit growth of malignant cells in vivo, carnosine should be considered as a potential anti-cancer drug. Further experiments should be performed in order to understand how carnosine acts at the molecular level.

Degradation of aqueous phenol solutions by coaxial DBD reactor

NASA Astrophysics Data System (ADS)

Dojcinovic, B. P.; Manojlovic, D.; Roglic, G. M.; Obradovic, B. M.; Kuraica, M. M.; Puric, J.

2008-07-01

Solutions of 2-chlorophenol, 4-chlorophenol and 2,6-dichlorophenol in bidistilled and water from the river Danube were treated in plasma reactor. In this reactor, based on coaxial dielectric barrier discharge at atmospheric pressure, plasma is formed over a thin layer of treated water. After one pass through the reactor, starting chlorophenols concentration of 20 mg/l was diminished up to 95 %. Kinetics of the chlorophenols degradation was monitored by High Pressure Liquid Chromatography method (HPLC).

Thermal cooling effects in the microstructure and properties of cast cobalt-base biomedical alloys

NASA Astrophysics Data System (ADS)

Vega Valer, Vladimir

Joint replacement prosthesis is widely used in the biomedical field to provide a solution for dysfunctional human body joints. The demand for orthopedic knee and hip implants motivate scientists and manufacturers to develop novel materials or to increase the life of service and efficiency of current materials. Cobalt-base alloys have been investigated by various researchers for biomedical implantations. When these alloys contain Chromium, Molybdenum, and Carbon, they exhibit good tribological and mechanical properties, as well as excellent biocompatibility and corrosion resistance. In this study, the microstructure of cast Co-Cr-Mo-C alloy is purposely modified by inducing rapid solidification through fusion welding processes and solution annealing heat treatment (quenched in water at room temperature. In particular the effect of high cooling rates on the athermal phase transformation FCC(gamma)↔HCP(epsilon) on the alloy hardness and corrosion resistance is investigated. The Co-alloy microstructures were characterized using metallography and microscopy techniques. It was found that the as cast sample typically dendritic with dendritic grain sizes of approximately 150 microm and containing Cr-rich coarse carbide precipitates along the interdendritic boundaries. Solution annealing gives rise to a refined microstructure with grain size of 30 microm, common among Co-Cr-Mo alloys after heat treating. Alternatively, an ultrafine grain structure (between 2 and 10 microm) was developed in the fusion zone for specimens melted using Laser and TIG welding methods. When laser surface modification treatments were implemented, the developed solidification microstructure shifted from dendritic to a fine cellular morphology, with possible nanoscale carbide precipitates along the cellular boundaries. In turn, the solidified regions exhibited high hardness values (461.5HV), which exceeds by almost 110 points from the alloy in the as-cast condition. The amount of developed athermal epsilon-martensite phase was determined using X-ray diffractrometry. It was found that the amount of epsilon-martensite increases significantly from 2% for the Laser surface processing to 13% in the as cast specimen, 24% in the annealed specimen, and 51% for the TIG surface processing. Moreover, the corrosion rate in Ringer solution was calculated by applying the Tafel extrapolation method on each alloy condition. The lowest corrosion rate (0.435 microm/year) was achieved in the Laser treated alloy and it is attributed to the lack of appreciable athermal epsilon-martensite. The highest corrosion rate (15.5 microm/year) was found to occur in the TIG treated alloy, which possesses the largest amount of epsilon-martensite. In turn, this suggests that surface modification through melting induces variable amounts of athermal epsilon-martensite in the as-cast Co-Cr-Mo-C alloys. Apparently, rapid solidification of melted surfaces in the Co-alloy is highly effective in modifying the induced amounts of HCP phase, and hence, the exhibited properties.

Influence of corn steep liquor and glucose on colonization of control and CCB (Cu/Cr/B)-treated wood by brown rot fungi

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

Humar, Miha; Amartey, Sam A.; Pohleven, Franc

2006-07-01

There are increasing problems with regard to the disposal of treated wood waste. Due to heavy metals or arsenic in impregnated wood waste, burning and landfill disposal options are not considered to be environmentally friendly solutions for dealing with this problem. Extraction of the heavy metals and recycling of the preservatives from the wood waste is a much more promising and environmentally friendly solution. In order to study the scale up of this process, copper/chromium/boron-treated wood specimens were exposed to copper tolerant (Antrodia vaillantii and Leucogyrophana pinastri) and copper sensitive wood decay fungi (Gloeophyllum trabeum and Poria monticola). Afterwards, themore » ability of fungal hyphae to penetrate and overgrow the wood specimens was investigated. The fungal growths were stimulated by immersing the specimens into aqueous solution of glucose or corn steep liquor prior to exposure to the fungi. The fastest colonization of the impregnated wood was by the copper tolerant A. vaillantii. Addition of glucose onto the surface of the wood specimens increased the fungi colonization of the specimens; however, immersion of the specimens into the solution of corn steep liquor did not have the same positive influence. These results are important in elucidating copper toxicity in wood decay fungi and for using these fungi for bioremediation of treated wood wastes.« less

APPROXIMATE AND ANALYTICAL SOLUTIONS FOR SOLUTE TRANSPORT FROM AN INJECTION WELL INTO A SINGLE FRACTURE

EPA Science Inventory

In dealing with problems related to land-based nuclear waste management, a number of analytical and approximate solutions were developed to quantify radionuclide transport through fractures contained in the porous formation. t has been reported that by treating the radioactive de...

EPI-001, a compound active against castration-resistant prostate cancer, targets transactivation unit 5 of the androgen receptor

PubMed Central

De Mol, Eva; Fenwick, R. Bryn; Phang, Christopher T. W.; Buzón, Victor; Szulc, Elzbieta; de la Fuente, Alex; Escobedo, Albert; García, Jesús; Bertoncini, Carlos W.; Estébanez-Perpiñá, Eva; McEwan, Iain J.; Riera, Antoni; Salvatella, Xavier

2016-01-01

Castration-resistant prostate cancer is the lethal condition suffered by prostate cancer patients that become refractory to androgen deprivation therapy. EPI-001 is a recently identified compound active against this condition that modulates the activity of the androgen receptor, a nuclear receptor that is essential for disease progression. The mechanism by which this compound exerts its inhibitory activity is however not yet fully understood. Here we show, by using high resolution solution nuclear magnetic resonance spectroscopy, that EPI-001 selectively interacts with a partially folded region of the transactivation domain of the androgen receptor, known as transactivation unit 5, that is key for the ability of prostate cells to proliferate in the absence of androgens, a distinctive feature of castration-resistant prostate cancer. Our results can contribute to the development of more potent and less toxic novel androgen receptor antagonists for treating this disease. PMID:27356095

Surgical management of recurrent urinary tract infections: a review

PubMed Central

Bergamin, Paul A.

2017-01-01

There are many causes of recurrent urinary tract infections (rUTI) which are amenable to surgical management. This usually follows a lengthy trial of conservative management. Aetiological classification of rUTI requiring surgical management may be divided into congenital or acquired. Predisposing factors are classified into two groups; those providing a source for organisms, or by maintaining favourable conditions for the proliferation of organisms. Sources of infections include calculi, fistulae or abscesses. Conditions which predispose to bacterial proliferation include malignancies, foreign bodies, high post void residuals, and neuropathic bladders. Removal of identified sources, treating the obstruction, and improving urinary drainage, are all goals of surgical management. Surgical options for rUTI management can range from minimally invasive procedures such as endoscopic or percutaneous, through to more invasive requiring laparoscopic or an open approach. Surgery remains a very important and viable solution. PMID:28791234

Surface treatment process of Al-Mg alloy powder by BTSPS

NASA Astrophysics Data System (ADS)

Zhao, Ran; Gao, Xinbao; Lu, Yanling; Du, Fengzhen; Zhang, Li; Liu, Dazhi; Chen, Xuefang

2018-04-01

The surface of Al-Mg alloy powder was treated by BTSPS(bis(triethoxysilylpropyl)tetrasulfide) in order to avoid easy oxidation in air. The pH value, reaction temperature, reaction time, and reaction concentration were used as test conditions. The results show that the BTSPS can form a protected film on the surface of Al-Mg alloy powder. Select the best test solution by orthogonal test. The study found that the reaction time and reaction temperature have the biggest influence on the two indexes of the orthogonal test (melting enthalpy of heat and enthalpy of oxidation). The optimal conditions were as follows: pH value is 8, reaction concentration is 2%, reaction temperature is 25 °C, reaction time is 2 h. The oxidation weight gain of the alloy reached 74.45% and the decomposition temperature of silane film is 181.8 °C.

Untargeted LC-MS/MS Profiling of Cell Culture Media Formulations for Evaluation of High Temperature Short Time Treatment Effects.

PubMed

Floris, Patrick; McGillicuddy, Nicola; Albrecht, Simone; Morrissey, Brian; Kaisermayer, Christian; Lindeberg, Anna; Bones, Jonathan

2017-09-19

An untargeted LC-MS/MS platform was implemented for monitoring variations in CHO cell culture media upon exposure to high temperature short time (HTST) treatment, a commonly used viral clearance upstream strategy. Chemically defined (CD) and hydrolysate-supplemented media formulations were not visibly altered by the treatment. The absence of solute precipitation effects during media treatment and very modest shifts in pH values observed indicated sufficient compatibility of the formulations evaluated with the HTST-processing conditions. Unsupervised chemometric analysis of LC-MS/MS data, however, revealed clear separation of HTST-treated samples from untreated counterparts as observed from analysis of principal components and hierarchical clustering sample grouping. An increased presence of Maillard products in HTST-treated formulations contributed to the observed differences which included organic acids, observed particularly in chemically defined formulations, and furans, pyridines, pyrazines, and pyrrolidines which were determined in hydrolysate-supplemented formulations. The presence of Maillard products in media did not affect cell culture performance with similar growth and viability profiles observed for CHO-K1 and CHO-DP12 cells when cultured using both HTST-treated and untreated media formulations.

The Effect of Rod-Shaped Long-Period Stacking Ordered Phases Evolution on Corrosion Behavior of Mg95.33Zn2Y2.67 Alloy

PubMed Central

Wang, Jingfeng; Jiang, Weiyan; Li, Yang; Ma, Yao

2018-01-01

The morphology evolution of long-period stacking ordered (LPSO) phases on corrosion behavior of Mg95.33Zn2Y2.67 alloy is investigated systematically during as-cast, pre-extrusion heat-treated, as-extruded and post-extrusion heat-treated conditions. The second phases in the as-cast alloy are only LPSO phases with a few Y particles. The pre-extrusion heat treatment changed LPSO phases from blocks into a rudimentary rod shape with lamellar structure, subsequently into fine fragments by extrusion, and then into a regular rod shape with lamellar structure followed by post-extrusion heat treatment. Immersion tests and electrochemical measurements in 3.5 wt % NaCl solution reveal that the post-extrusion heat-treated alloy has the best corrosion resistance with the lowest corrosion rate. This is attributed to the rod-shaped LPSO phases, which could hinder corrosion proceeding, and result in corrosion orientated along the direction of rods and forming relatively dense long-strip corrosion products. Our findings demonstrate that the improved corrosion resistance of magnesium alloys with LPSO phases can be tailored effectively by the proceeding technology and post-heat treatment. PMID:29772721

Tumour chemotherapy strategy based on impulse control theory.

PubMed

Ren, Hai-Peng; Yang, Yan; Baptista, Murilo S; Grebogi, Celso

2017-03-06

Chemotherapy is a widely accepted method for tumour treatment. A medical doctor usually treats patients periodically with an amount of drug according to empirical medicine guides. From the point of view of cybernetics, this procedure is an impulse control system, where the amount and frequency of drug used can be determined analytically using the impulse control theory. In this paper, the stability of a chemotherapy treatment of a tumour is analysed applying the impulse control theory. The globally stable condition for prescription of a periodic oscillatory chemotherapeutic agent is derived. The permanence of the solution of the treatment process is verified using the Lyapunov function and the comparison theorem. Finally, we provide the values for the strength and the time interval that the chemotherapeutic agent needs to be applied such that the proposed impulse chemotherapy can eliminate the tumour cells and preserve the immune cells. The results given in the paper provide an analytical formula to guide medical doctors to choose the theoretical minimum amount of drug to treat the cancer and prevent harming the patients because of over-treating.This article is part of the themed issue 'Horizons of cybernetical physics'. © 2017 The Author(s).

No increase in small-solute transport in peritoneal dialysis patients treated without hypertonic glucose for fifty-four months.

PubMed

Pagniez, Dominique; Duhamel, Alain; Boulanger, Eric; Lessore de Sainte Foy, Celia; Beuscart, Jean-Baptiste

2017-08-31

Glucose is widely used as an osmotic agent in peritoneal dialysis (PD), but exerts untoward effects on the peritoneum. The potential protective effect of a reduced exposure to hypertonic glucose has never been investigated. The cohort of PD patients attending our center which tackled the challenge of a restricted use of hypertonic glucose solutions has been prospectively followed since 1992. Small-solute transport was assessed using an equivalent of the glucose peritoneal equilibration test after 6 months, and then every year. Study was stopped on July 1st, 2008, before use of biocompatible solutions. Repeated measures in patients treated with PD for 54 months were analyzed by using (1) the slopes of the linear regression for D 4 /D 0 ratios over time computed for each individual, and (2) a linear mixed model. In the study period, 44 patients were treated for a total of 2376 months, 2058 without hypertonic glucose. There was one episode of peritoneal infection every 18 patient-months. The mean of slopes of the linear regression for D 4 /D 0 ratios was found to be significantly positive (Student's test, p < .001) and the results of the mixed model reflected a similar significant increase for D 4 /D 0 ratios over time. These results reflected a significant decrease of small-solute transport. In this large series, minimizing the use of hypertonic glucose solutions was associated in patients on long term PD with an overall decrease of small-solute transport within 54 months, despite a high rate of peritoneal infection.

Homogenous UV/periodate process in treatment of p-nitrophenol aqueous solutions under mild operating conditions.

PubMed

Saien, Javad; Fallah Vahed Bazkiaei, Marzieh

2018-07-01

Aqueous solutions of p-nitrophenol (PNP) were treated with UV-activated potassium periodate (UV/KPI) in an efficient photo-reactor. Either periodate or UV alone had little effect; however, their combination led to a significant degradation and mineralization. The response surface methodology was employed for design of experiments and optimization. The optimum conditions for treatment of 30 mg/L of the substrate were determined as [KPI] = 386.3 mg/L, pH = 6.2 and T = 34.6°C, under which 79.5% degradation was achieved after 60 min. Use of 25 and 40 kHz ultrasound waves caused the degradation to enhance to 88.3% and 92.3%, respectively. The intermediates were identified by gas chromatography-mass spectroscopy analysis, leading to propose the reaction pathway. The presence of water conventional bicarbonate, chloride, sulfate and nitrate anions caused unfavorable effects in efficiency. Meanwhile, the kinetic study showed that PNP degradation follows a pseudo-first-order reaction and the activation energy was determined. The irradiation energy consumption required for one order of magnitude degradation was estimated as 11.18 kWh/m 3 . Accordingly, comparison with the previously reported processes showed the superiority of PNP treatment with the employed process.

On the stability of a superspinar

NASA Astrophysics Data System (ADS)

Nakao, Ken-ichi; Joshi, Pankaj S.; Guo, Jun-Qi; Kocherlakota, Prashant; Tagoshi, Hideyuki; Harada, Tomohiro; Patil, Mandar; Królak, Andrzej

2018-05-01

The superspinar proposed by Gimon and Hořava is a rapidly rotating compact entity whose exterior is described by the over-spinning Kerr geometry. The compact entity itself is expected to be governed by superstringy effects, and in astrophysical scenarios it can give rise to interesting observable phenomena. Earlier it was suggested that the superspinar may not be stable but we point out here that this does not necessarily follow from earlier studies. We show, by analytically treating the Teukolsky equations by Detwiler's method, that in fact there are infinitely many boundary conditions that make the superspinar stable at least against the linear perturbations of m = l modes, and that the modes will decay in time. Further consideration leads us to the conclusion that it is possible to set the inverse problem to the linear stability issue: since the radial Teukolsky equation for the superspinar has no singular point on the real axis, we obtain regular solutions to the Teukolsky equation for arbitrary discrete frequency spectrum of the quasi-normal modes (no incoming waves) and the boundary conditions at the "surface" of the superspinar are found from obtained solutions. It follows that we need to know more on the physical nature of the superspinar in order to decide on its stability in physical reality.

Optimal flow conditions of a tracheobronchial model to reengineer lung structures

NASA Astrophysics Data System (ADS)

Casarin, Stefano; Aletti, Federico; Baselli, Giuseppe; Garbey, Marc

2017-04-01

The high demand for lung transplants cannot be matched by an adequate number of lungs from donors. Since fully ex-novo lungs are far from being feasible, tissue engineering is actively considering implantation of engineered lungs where the devitalized structure of a donor is used as scaffold to be repopulated by stem cells of the receiving patient. A decellularized donated lung is treated inside a bioreactor where transport through the tracheobronchial tree (TBT) will allow for both deposition of stem cells and nourishment for their subsequent growth, thus developing new lung tissue. The key concern is to set optimally the boundary conditions to utilize in the bioreactor. We propose a predictive model of slow liquid ventilation, which combines a one-dimensional (1-D) mathematical model of the TBT and a solute deposition model strongly dependent on fluid velocity across the tree. With it, we were able to track and drive the concentration of a generic solute across the airways, looking for its optimal distribution. This was given by properly adjusting the pumps' regime serving the bioreactor. A feedback system, created by coupling the two models, allowed us to derive the optimal pattern. The TBT model can be easily invertible, thus yielding a straightforward flow/pressure law at the inlet to optimize the efficiency of the bioreactor.

The concept of entropy in landscape evolution

USGS Publications Warehouse

Leopold, Luna Bergere; Langbein, Walter Basil

1962-01-01

The concept of entropy is expressed in terms of probability of various states. Entropy treats of the distribution of energy. The principle is introduced that the most probable condition exists when energy in a river system is as uniformly distributed as may be permitted by physical constraints. From these general considerations equations for the longitudinal profiles of rivers are derived that are mathematically comparable to those observed in the field. The most probable river profiles approach the condition in which the downstream rate of production of entropy per unit mass is constant. Hydraulic equations are insufficient to determine the velocity, depths, and slopes of rivers that are themselves authors of their own hydraulic geometries. A solution becomes possible by introducing the concept that the distribution of energy tends toward the most probable. This solution leads to a theoretical definition of the hydraulic geometry of river channels that agrees closely with field observations. The most probable state for certain physical systems can also be illustrated by random-walk models. Average longitudinal profiles and drainage networks were so derived and these have the properties implied by the theory. The drainage networks derived from random walks have some of the principal properties demonstrated by the Horton analysis; specifically, the logarithms of stream length and stream numbers are proportional to stream order.

On the Analysis of the Printing Nip on Sheetfed Lithographic Presses and its Implications on the Runnability of Common Substrates

NASA Astrophysics Data System (ADS)

Diaz, Francisco J.

This dissertation is based on the thesis that: Adequate analysis of the offset printing nip, under proper solutions of the Navier-Stokes equations---NSE---for the ink flow and, every day common sense, must provide answers to relevant questions still pending response in the offset printing process. Among these questions are: the influence of wall pressure on the flow, the presence or lack thereof of cavitation, the influence of the Newtonian and non- Newtonian conditions of the ink and, the validity of Stefan's law in the flow as ink and substrate split from the blanket/ink interface. As those questions are properly studied and, solutions are provided on the influence of the ink flow on common substrates (mainly focused on coated papers). Answers are presented on ink velocity profiles, influence of ink viscosity and ink layer height (under full ink coverage), and adequate release of the substrate at common SFO---Sheet Fed Offset---printing conditions. In order to understand the flow, a model is proposed by using a thin channel, high aspect ratio, based on the very thin ink layer running at 2 microns (2 x 10--6 m) through a long contacting channel S, of 0.012 m, while the walls move at a set velocity of 3 m/s and known contacting pressure (peaking at the center at 1 MPa). The problem is divided in two regions with similar geometry (high aspect ratio) but, with different boundary conditions. Inside the nip, the problem is a Couette-like flow. Once it leaves the nip, the problem turns into an adhesion matter. Due the high aspect ratio, NSE can be simplified to the Lubrication Approximation Equations---LAE. The printing process is absolutely symmetric in the depth direction of the flow---considered here as y-direction in accordance with paper physics literature---, validating the simplification of the study from 3D to 2D. The physics and geometry of the flow indicate as well that: the fluid is incompressible, the interaction of the ink and substrate happen very rapidly and prevent any change in the ink viscosity, the temperature of the system is constant and heat transfer has no influence on the analysis. In addition, curvature is negligible and finally, wall pressure is known (through work developed here using Finite Element Methods). Since wall pressure is known, its derivative is also known and NSE can be solved swiftly by successive integration under the printing boundary conditions. Each of these assumptions is discussed in this dissertation and proven to be valid for the analysis of the flow in the offset printing nip. As a result of the analysis, it is found that solutions for the NSE, under Newtonian and non-Newtonian (Power Law viscosity model), provide a very similar profile for the fluid's velocity field. This is also true for the region of adhesion at nip's exit. The analysis presented here supports the simplification of treating offset ink as a Newtonian fluid since the results for ink flow velocity are rather similar. The influence of porosity at the bottom wall, treated as a boundary conditions for the solution of the flow, proves to be very minimal. Similarity simplifications such as Berman-Blassius are not instrumental in the analysis of the printing nip, since the result is completely impervious to porosity. The solution through LAE provide adequate and reasonable solutions to the ink flow. LAE serve at nip's exit, under adhesion solutions in cylindrical coordinates (offered by other researchers) and, in rectangular coordinates developed in this dissertation under the Reynolds adhesion equation to find answers for ink internal pressure and extension. The action of the ink extension serves as a means to predict adequate sheet release from the blanket. It is used as well to determine the ability of the ink flow to release without surface damage (eventual surface picking or delamination). Ink extension provides adequate understanding of the definition for Runnablity in z-direction as proposed here.

Study of the electrochemical oxidation and reduction of C.I. Reactive Orange 4 in sodium sulphate alkaline solutions.

PubMed

del Río, A I; Molina, J; Bonastre, J; Cases, F

2009-12-15

Synthetic solutions of hydrolysed C.I. Reactive Orange 4, a monoazo textile dye commercially named Procion Orange MX-2R (PMX2R) and colour index number C.I. 18260, was exposed to electrochemical treatment under galvanostatic conditions and Na2SO4 as electrolyte. The influence of the electrochemical process as well as the applied current density was evaluated. Ti/SnO2-Sb-Pt and stainless steel electrodes were used as anode and cathode, respectively, and the intermediates generated on the cathode during electrochemical reduction were investigated. Aliquots of the solutions treated were analysed by UV-visible and FTIR-ATR spectroscopy confirming the presence of aromatic structures in solution when an electro-reduction was carried out. Electro-oxidation degraded both the azo group and aromatic structures. HPLC measures revealed that all processes followed pseudo-first order kinetics and decolourisation rates showed a considerable dependency on the applied current density. CV experiments and XPS analyses were carried out to study the behaviour of both PMX2R and intermediates and to analyse the state of the cathode after the electrochemical reduction, respectively. It was observed the presence of a main intermediate in solution after an electrochemical reduction whose chemical structure is similar to 2-amino-1,5-naphthalenedisulphonic acid. Moreover, the analysis of the cathode surface after electrochemical reduction reveals the presence of a coating layer with organic nature.

Invariants of the Jacobi-Porstendorfer room model for radon progeny in indoor air.

PubMed

Thomas, Josef; Jilek, Karel

2012-06-01

The Jacobi-Porstendörfer room model, describing the dynamical behaviour of radon and radon progeny in indoor air, has been successfully used for decades. The inversion of the model-the determination of the five parameters from measured results which provide better information on the room environment than mere ratios of unattached and attached radon progeny-is treated as an algebraic task. The linear interdependence of the used equations strongly limits the algebraic invertibility of experimental results. For a unique solution, the fulfilment of two invariants of the room model for the measured results is required. Non-fulfilment of these model invariants by the measured results leads to a set of non-identical solutions and indicates the violation of the conditions required by the room model or the incorrectness or excessive uncertainties of the measured results. The limited and non-unique algebraic invertibility of the room model is analysed numerically using our own data for the radon progeny.

Radiative Heat Transfer in Finite Cylindrical Enclosures with Nonhomogeneous Participating Media

NASA Technical Reports Server (NTRS)

Hsu, Pei-Feng; Ku, Jerry C.

1994-01-01

Results of a numerical solution for radiative heat transfer in homogeneous and nonhomogeneous participating media are presented. The geometry of interest is a finite axisymmetric cylindrical enclosure. The integral formulation for radiative transport is solved by the YIX method. A three-dimensional solution scheme is applied to two-dimensional axisymmetric geometry to simplify kernel calculations and to avoid difficulties associated with treating boundary conditions. As part of the effort to improve modeling capabilities for turbulent jet diffusion flames, predicted distributions for flame temperature and soot volume fraction are used to calculate radiative heat transfer from soot particles in such flames. It is shown that the nonhomogeneity of radiative property has very significant effects. The peak value of the divergence of radiative heat flux could be underestimated by 2 factor of 7 if a mean homogeneous radiative property is used. Since recent studies have shown that scattering by soot agglomerates is significant in flames, the effect of magnitude of scattering is also investigated and found to be nonnegligible.

Zero-gravity aerosol behavior

NASA Technical Reports Server (NTRS)

Edwards, H. W.

1981-01-01

The feasibility and scientific benefits of a zero gravity aerosol study in an orbiting laboratory were examined. A macroscopic model was devised to deal with the simultaneous effects of diffusion and coagulation of particles in the confined aerosol. An analytical solution was found by treating the particle coagulation and diffusion constants as ensemble parameters and employing a transformation of variables. The solution was used to carry out simulated zero gravity aerosol decay experiments in a compact cylindrical chamber. The results demonstrate that the limitations of physical space and time imposed by the orbital situation are not prohibitive in terms of observing the history of an aerosol confined under zero gravity conditions. While the absence of convective effects would be a definite benefit for the experiment, the mathematical complexity of the problem is not greatly reduced when the gravitational term drops out of the equation. Since the model does not deal directly with the evolution of the particle size distribution, it may be desirable to develop more detailed models before undertaking an orbital experiment.

Phytoremediation potential of Arundo donax in arsenic-contaminated synthetic wastewater.

PubMed

Mirza, Nosheen; Mahmood, Qaisar; Pervez, Arshid; Ahmad, Raza; Farooq, Robina; Shah, Mohammad Maroof; Azim, Muhammad Rashid

2010-08-01

The present study reports the potential of Arundo donax for phytoextraction of arsenic from synthetic wastewater. A. donax plants were grown under greenhouse conditions in pots containing a nutrient solution amended with increasing doses of As (0, 50, 100, 300, 600 and 1000 microg L(-1)) for 21 days in a completely randomized design. Shoot and roots dry matter production, growth parameters, arsenic and nutrient tissue concentrations were measured at the end of the experiment. Increasing As concentration in nutrient solution caused an increase in shoot and root biomass without toxicity symptoms in A. donax growing under a range of As concentration from 50 to 600 microg L(-1). Elevated oxidative stress was observed at As supplied level of 1000 microg L(-1). The As doses up to 600 microg L(-1) did not affect the growth of A. donax. It is suggested that A. donax plants may be employed to treat contaminated waters containing arsenic concentrations up to 600 microg L(-1). (c) 2010 Elsevier Ltd. All rights reserved.

Treatment of diazo dye C.I. Reactive Black 5 in aqueous solution by combined process of interior microelectrolysis and ozonation.

PubMed

Guo, Xiaoyan; Cai, Yaping; Wei, Zhongbo; Hou, Haifeng; Yang, Xi; Wang, Zunyao

2013-01-01

Interior microelectrolysis (IM) as a pretreatment process was effective to treat Reactive Black 5 (RB5) in this study. The removal rates of chemical oxygen demand (COD), total organic carbon (TOC) and color were 46.05, 39.99 and 98.77%, respectively, when this process was conducted under the following optimal conditions: the volumetric ratio between iron scraps and active carbon (AC) (V(Fe)/V(C)) 1.0, pH 2.0, aeration dosage 0.6 L/min, and reaction time 100 min. Contaminants could be further removed by ozonation. After subsequent ozonation for 200 min, the solution could be completely decolorized, and the COD and TOC removal rates were up to 77.78 and 66.51%, respectively. In addition, acute toxicity tests with Daphnia magna showed that pretreatment by IM generated effluents that were more toxic when compared with the initial wastewater, and the toxicity was reduced after subsequent ozonation.

Fabrication and Physical Evaluation of Gelatin-Coated Carbonate Apatite Foam.

PubMed

Hara, Kanae; Fujisawa, Kenji; Nagai, Hirokazu; Takamaru, Natsumi; Ohe, Go; Tsuru, Kanji; Ishikawa, Kunio; Miyamoto, Youji

2016-08-23

Carbonate apatite (CO₃Ap) foam has gained much attention in recent years because of its ability to rapidly replace bone. However, its mechanical strength is extremely low for clinical use. In this study, to understand the potential of gelatin-reinforced CO₃Ap foam for bone replacement, CO₃Ap foam was reinforced with gelatin and the resulting physical characteristics were evaluated. The mechanical strength increased significantly with the gelatin reinforcement. The compressive strength of gelatin-free CO₃Ap foam was 74 kPa whereas that of the gelatin-reinforced CO₃Ap foam, fabricated using 30 mass % gelatin solution, was approximately 3 MPa. Heat treatment for crosslinking gelatin had little effect on the mechanical strength of the foam. The gelatin-reinforced foam did not maintain its shape when immersed in a saline solution as this promoted swelling of the gelatin; however, in the same conditions, the heat-treated gelatin-reinforced foam proved to be stable. It is concluded, therefore, that heat treatment is the key to the fabrication of stable gelatin-reinforced CO₃Ap foam.

On the superposition of strengthening mechanisms in dispersion strengthened alloys and metal-matrix nanocomposites: Considerations of stress and energy

NASA Astrophysics Data System (ADS)

Ferguson, J. B.; Schultz, Benjamin F.; Venugopalan, Dev; Lopez, Hugo F.; Rohatgi, Pradeep K.; Cho, Kyu; Kim, Chang-Soo

2014-03-01

Yield strength improvement in dispersion strengthened alloys and nano particle-reinforced composites by well-known strengthening mechanisms such as solid solution, grain refinement, coherent and incoherent dispersed particles, and increased dislocation density resulting from work-hardening can all be described individually. However, there is no agreed upon description of how these mechanisms combine to determine the yield strength. In this work, we propose an analytical yield strength prediction model combining arithmetic and quadratic addition approaches based on the consideration of two types of yielding mechanisms; stress-activated and energy-activated. Using data available in the literature for materials of differing grain sizes, we consider the cases of solid solutions and coherent precipitates to show that they follow stress-activated behavior. Then, we applied our model with some empirical parameters to precipitationhardenable materials of various grain sizes in both coherent and incoherent precipitate conditions, which demonstrated that grain boundary and Orowan-strengthening can be treated as energy-activated mechanisms.

The application of bioflocculant for the removal of humic acids from stabilized landfill leachates.

PubMed

Zouboulis, Anastasios I; Chai, Xiao-Li; Katsoyiannis, Ioannis A

2004-01-01

The evaluation of bioflocculant, in comparison with traditional inorganic coagulants, for the removal of humic acids from landfill leachates stabilized by biological treatment, was performed using conventional jar-test coagulation experiments. The optimized conditions (pH and coagulant dosage) were identified for the treatment of synthetic solutions as well as for biologically pre-treated landfill leachates. It was found that the application of bioflocculant was quite efficient in the removal of humic acids from synthetic solutions as well as in the reduction of COD content from real landfill leachates. The optimal pH value was found to be between 7 and 7.5, while a 20 mg/l bioflocculant dosage was sufficient in providing more than 85% humic acid removal. The results were comparable with those obtained by the application of conventional coagulants such as alum or polyaluminum chloride; therefore, bioflocculant can be considered as a viable alternative in the treatment of landfill leachates applying coagulation.

Isotherm-Based Thermodynamic Model for Solute Activities of Asymmetric Electrolyte Aqueous Solutions.

PubMed

Nandy, Lucy; Dutcher, Cari S

2017-09-21

Adsorption isotherm-based statistical thermodynamic models can be used to determine solute concentration and solute and solvent activities in aqueous solutions. Recently, the number of adjustable parameters in the isotherm model of Dutcher et al. J. Phys. Chem. A/C 2011, 2012, 2013 were reduced for neutral solutes as well as symmetric 1:1 electrolytes by using a Coulombic model to describe the solute-solvent energy interactions (Ohm et al. J. Phys. Chem. A 2015, Nandy et al. J. Phys. Chem. A 2016). Here, the Coulombic treatment for symmetric electrolytes is extended to establish improved isotherm model equations for asymmetric 1-2 and 1-3 electrolyte systems. The Coulombic model developed here results in prediction of activities and other thermodynamic properties in multicomponent systems containing ions of arbitrary charge. The model is found to accurately calculate the osmotic coefficient over the entire solute concentration range with two model parameters, related to intermolecular solute-solute and solute-solvent spacing. The inorganic salts and acids treated here are generally considered to be fully dissociated. However, there are certain weak acids that do not dissociate completely, such as the bisulfate ion. In this work, partial dissociation of the bisulfate ion from sulfuric acid is treated as a mixture, with an additional model parameter that accounts for the dissociation ratio of the dissociated ions to nondissociated ions.

Non-invasive, multi-modal sensing of skin stretch and bioimpedance for detecting infiltration during intravenous therapy.

PubMed

Jambulingam, Jambu A; McCrory, Russell; West, Leanne; Inan, Omer T

2016-08-01

Intravenous infiltration is a condition wherein an infused solution leaks inadvertently into soft tissue surrounding a hypodermic needle site. This occurrence affects approximately 6.5% of patients in hospitals worldwide, and can lead to severe tissue damage if not treated immediately. The methods currently used by medical staff to detect an infiltration are subjective and can potentially be prone to error. Infiltration is an even larger concern in pediatric patients, who have smaller veins than adults and have more difficulty in communicating pain or other discomfort associated with the infiltration with medical staff. For these reasons, automatic IV infiltration detection could potentially reduce the risk associated with this damaging condition. This paper proposes a novel proof-of-concept system that uses non-invasive sensing in conjunction with a low-power embedded computing platform to deliver continuous infiltration monitoring around the IV catheter site. This kind of system could be able to detect an infiltration by non-invasively monitoring for known symptoms: swelling of soft tissue and increased skin firmness; these symptoms can be sensed by measuring skin stretch and local bioimpedance. Moreover, the low-power design and wireless capabilities can potentially enable continuous wear. The proposed automatic IV infiltration detection system could significantly improve the number of infiltrations identified and treated on time.

Acaricidal activity of thymol against larvae of Rhipicephalus microplus (Acari: Ixodidae) under semi-natural conditions.

PubMed

Araújo, Laryssa Xavier; Novato, Tatiane Pinheiro Lopes; Zeringota, Viviane; Matos, Renata Silva; Senra, Tatiane Oliveira Souza; Maturano, Ralph; Prata, Márcia Cristina Azevedo; Daemon, Erik; Monteiro, Caio Márcio Oliveira

2015-09-01

This is the first study to investigate the activity of thymol on Rhipicephalus microplus larvae under semi-natural conditions. For this purpose, tests were conducted in pots with Brachiaria decumbens seedlings containing cattle tick larvae. Thymol, diluted in ethanol 50° GL, was tested at concentrations of 2.5, 5.0, 10.0, 15.0, and 20.0 mg/mL, along with the control group treated with the solvent alone. Each treatment was composed of five pots (1 pot = a repetition). The experiment was performed in three steps. On the first day, the larvae were applied at the base of the signalgrass. Twenty-four hours later, approximately 25 mL of the solution was applied with thymol on the top of the vegetation in each pot. The survival of the larvae was measured 24 h after application of the solutions. Each pot was analyzed individually, and the grass fillets contained larvae were cut with scissors, placed in Petri dishes, and taken to the laboratory to count the number of living larvae. At the highest concentrations (10, 15, and 20 mg /mL), the number of live larvae declined by more than 95 % in relation to the control group. The lethal concentration 50 % (LC50) and LC90 values were 3.45 and 9.25 mg/ml, respectively. The application of thymol in semi-natural conditions starting concentration of 10 mg/mL significantly reduced the number of living R. microplus larvae.

Novel Electrokinetic Microfluidic Detector for Evaluating Effectiveness of Microalgae Disinfection in Ship Ballast Water

PubMed Central

Maw, Myint Myint; Wang, Junsheng; Li, Fabo; Jiang, Jinhu; Song, Younan; Pan, Xinxiang

2015-01-01

Ship ballast water treatment methods face many technical challenges. The effectiveness of every treatment method usually is evaluated by using large scale equipment and a large volume of samples, which involves time-consuming, laborious, and complex operations. This paper reports the development of a novel, simple and fast platform of methodology in evaluating the efficiency and the best parameters for ballast water treatment systems, particularly in chemical disinfection. In this study, a microfluidic chip with six sample wells and a waste well was designed, where sample transportation was controlled by electrokinetic flow. The performance of this microfluidic platform was evaluated by detecting the disinfection of Dunaliella salina (D. salina) algae in ballast water treated by sodium hypochlorite (NaClO) solution. Light-induced chlorophyll fluorescence (LICF) intensity was used to determine the viability of microalgae cells in the system, which can be operated automatically with the dimension of the detector as small as 50 mm × 24 mm × 5 mm. The 40 µL volume of sample solution was used for each treatment condition test and the validity of detection can be accomplished within about five min. The results show that the viability of microalgae cells under different treatment conditions can be determined accurately and further optimal treatment conditions including concentrations of NaClO and treatment time can also be obtained. These results can provide accurate evaluation and optimal parameters for ballast water treatment methods. PMID:26516836

An image-based reaction field method for electrostatic interactions in molecular dynamics simulations of aqueous solutions

NASA Astrophysics Data System (ADS)

Lin, Yuchun; Baumketner, Andrij; Deng, Shaozhong; Xu, Zhenli; Jacobs, Donald; Cai, Wei

2009-10-01

In this paper, a new solvation model is proposed for simulations of biomolecules in aqueous solutions that combines the strengths of explicit and implicit solvent representations. Solute molecules are placed in a spherical cavity filled with explicit water, thus providing microscopic detail where it is most needed. Solvent outside of the cavity is modeled as a dielectric continuum whose effect on the solute is treated through the reaction field corrections. With this explicit/implicit model, the electrostatic potential represents a solute molecule in an infinite bath of solvent, thus avoiding unphysical interactions between periodic images of the solute commonly used in the lattice-sum explicit solvent simulations. For improved computational efficiency, our model employs an accurate and efficient multiple-image charge method to compute reaction fields together with the fast multipole method for the direct Coulomb interactions. To minimize the surface effects, periodic boundary conditions are employed for nonelectrostatic interactions. The proposed model is applied to study liquid water. The effect of model parameters, which include the size of the cavity, the number of image charges used to compute reaction field, and the thickness of the buffer layer, is investigated in comparison with the particle-mesh Ewald simulations as a reference. An optimal set of parameters is obtained that allows for a faithful representation of many structural, dielectric, and dynamic properties of the simulated water, while maintaining manageable computational cost. With controlled and adjustable accuracy of the multiple-image charge representation of the reaction field, it is concluded that the employed model achieves convergence with only one image charge in the case of pure water. Future applications to pKa calculations, conformational sampling of solvated biomolecules and electrolyte solutions are briefly discussed.

DIANA: A multi-phase, multi-component hydrodynamic model for the analysis of severe accidents in heavy water reactors with multiple-tube assemblies

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

Tentner, A.M.

1994-03-01

A detailed hydrodynamic fuel relocation model has been developed for the analysis of severe accidents in Heavy Water Reactors with multiple-tube Assemblies. This model describes the Fuel Disruption and Relocation inside a nuclear fuel assembly and is designated by the acronym DIANA. DIANA solves the transient hydrodynamic equations for all the moving materials in the core and treats all the relevant flow regimes. The numerical solution techniques and some of the physical models included in DIANA have been developed taking advantage of the extensive experience accumulated in the development and validation of the LEVITATE (1) fuel relocation model of SAS4Amore » [2, 3]. The model is designed to handle the fuel and cladding relocation in both voided and partially voided channels. It is able to treat a wide range of thermal/ hydraulic/neutronic conditions and the presence of various flow regimes at different axial locations within the same hydrodynamic channel.« less

Computation of the inviscid supersonic flow about cones at large angles of attack by a floating discontinuity approach

NASA Technical Reports Server (NTRS)

Daywitt, J.; Kutler, P.; Anderson, D.

1977-01-01

The technique of floating shock fitting is adapted to the computation of the inviscid flowfield about circular cones in a supersonic free stream at angles of attack that exceed the cone half-angle. The resulting equations are applicable over the complete range of free-stream Mach numbers, angles of attack and cone half-angles for which the bow shock is attached. A finite difference algorithm is used to obtain the solution by an unsteady relaxation approach. The bow shock, embedded cross-flow shock, and vortical singularity in the leeward symmetry plane are treated as floating discontinuities in a fixed computational mesh. Where possible, the flowfield is partitioned into windward, shoulder, and leeward regions with each region computed separately to achieve maximum computational efficiency. An alternative shock fitting technique which treats the bow shock as a computational boundary is developed and compared with the floating-fitting approach. Several surface boundary condition schemes are also analyzed.

Decision making tools for selecting sustainable wastewater treatment technologies in Thailand

NASA Astrophysics Data System (ADS)

Wongburi, Praewa; Park, Jae K.

2018-05-01

Wastewater consists of valuable resources that could be recovered or reused. Still it is under threat because of ineffective wastewater management and systems. In Thailand, less than 25% of wastewater generated may be treated while then rest is inadequately treated and sent back directly into waterbodies or the environment. Furthermore, the technologies that have been applied may be inefficient and unsustainable. Efficiency, sustainability, and simplicity are important concepts when designing an appropriate wastewater treatment system in developing countries. The objectives of this study were to review and evaluate wastewater treatment technologies and propose a method to improve or select an appropriate technology. An expert system in Excel® program was developed to determine the best solution. Sensitivity analysis was applied to compare and assess uncertainty factors. Due to the different conditions of each area, the key factor of interest was varied. Furthermore, Robust Decision Making tool was applied to determine the best way to improve existing wastewater treatment facility and to choose the most appropriate wastewater treatment technology.

Dependence of Interaction Free Energy between Solutes on an External Electrostatic Field

PubMed Central

Yang, Pei-Kun

2013-01-01

To explore the athermal effect of an external electrostatic field on the stabilities of protein conformations and the binding affinities of protein-protein/ligand interactions, the dependences of the polar and hydrophobic interactions on the external electrostatic field, −Eext, were studied using molecular dynamics (MD) simulations. By decomposing Eext into, along, and perpendicular to the direction formed by the two solutes, the effect of Eext on the interactions between these two solutes can be estimated based on the effects from these two components. Eext was applied along the direction of the electric dipole formed by two solutes with opposite charges. The attractive interaction free energy between these two solutes decreased for solutes treated as point charges. In contrast, the attractive interaction free energy between these two solutes increased, as observed by MD simulations, for Eext = 40 or 60 MV/cm. Eext was applied perpendicular to the direction of the electric dipole formed by these two solutes. The attractive interaction free energy was increased for Eext = 100 MV/cm as a result of dielectric saturation. The force on the solutes along the direction of Eext computed from MD simulations was greater than that estimated from a continuum solvent in which the solutes were treated as point charges. To explore the hydrophobic interactions, Eext was applied to a water cluster containing two neutral solutes. The repulsive force between these solutes was decreased/increased for Eext along/perpendicular to the direction of the electric dipole formed by these two solutes. PMID:23852018

Use of hydroponics culture to assess nutrient supply by treated wastewater.

PubMed

Adrover, Maria; Moyà, Gabriel; Vadell, Jaume

2013-09-30

The use of treated wastewater for irrigation is increasing, especially in those areas where water resources are limited. Treated wastewaters contain nutrients that are useful for plant growth and help to reduce fertilizers needs. Nutrient content of these waters depends on the treatment system. Nutrient supply by a treated wastewater from a conventional treatment plant (CWW) and a lagooned wastewater from the campus of the University of Balearic Islands (LWW) was tested in an experiment in hydroponics conditions. Half-strength Hoagland nutrient solution (HNS) was used as a control. Barley (Hordeum vulgare L.) seedlings were grown in 4 L containers filled with the three types of water. Four weeks after planting, barley was harvested and root and shoot biomass was measured. N, P, K, Ca, Mg, Na and Fe contents were determined in both tissues and heavy metal concentrations were analysed in shoots. N, P and K concentrations were lower in LWW than in CWW, while HNS had the highest nutrient concentration. Dry weight barley production was reduced in CWW and LWW treatments to 49% and 17%, respectively, comparing to HNS. However, to a lesser extent, reduction was found in shoot and root N content. Treated wastewater increased Na content in shoots and roots of barley and Ca and Cr content in shoots. However, heavy metals content was lower than toxic levels in all the cases. Although treated wastewater is an interesting water resource, additional fertilization is needed to maintain a high productivity in barley seedlings. Copyright © 2013 Elsevier Ltd. All rights reserved.

Surface analytical study of CuInSe[sub 2] treated in Cd-containing partial electrolyte solution

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

Asher, S.E.; Ramanathan, K.; Wiesner, H.

1999-03-01

Junction formation in CuInSe[sub 2] (CIS) has been studied by exposing thin films and single-crystal samples to solutions containing NH[sub 4]OH and CdSO[sub 4]. The treated samples were analyzed by secondary ion mass spectrometry to determine the amount and distribution of Cd deposited on the surface of the films. Cadmium is found to react with the surface for all the solution exposure times and temperatures studied. The reaction rapidly approaches the endpoint and remains relatively unchanged for subsequent solution exposure. Cadmium in-diffusion, as measured by secondary ion mass spectrometry, is obscured by topography effects in the thin-film samples and bymore » ion-beam mixing and topography in the single-crystal sample. [copyright] [ital 1999 American Institute of Physics.]« less

Surface analytical study of CuInSe{sub 2} treated in Cd-containing partial electrolyte solution

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

Asher, S.E.; Ramanathan, K.; Wiesner, H.

1999-03-01

Junction formation in CuInSe{sub 2} (CIS) has been studied by exposing thin films and single-crystal samples to solutions containing NH{sub 4}OH and CdSO{sub 4}. The treated samples were analyzed by secondary ion mass spectrometry to determine the amount and distribution of Cd deposited on the surface of the films. Cadmium is found to react with the surface for all the solution exposure times and temperatures studied. The reaction rapidly approaches the endpoint and remains relatively unchanged for subsequent solution exposure. Cadmium in-diffusion, as measured by secondary ion mass spectrometry, is obscured by topography effects in the thin-film samples and bymore » ion-beam mixing and topography in the single-crystal sample. {copyright} {ital 1999 American Institute of Physics.}« less

Protein Carbamylation in Peritoneal Dialysis and the Effect of Low Glucose Plus Amino Acid Solutions.

PubMed

Trottier, Caitlin; Perl, Jeffrey; Freeman, Megan; Thadhani, Ravi; Berg, Anders; Kalim, Sahir

2018-01-01

Protein carbamylation is a post-translational urea-driven protein modification associated with mortality. Free amino acids (AAs) competitively inhibit protein carbamylation and parenteral AA therapy reduces carbamylation in hemodialysis (HD) patients. Peritoneal dialysis (PD) yields differences in urea clearance and AA balance compared with HD, but the influence of PD and intraperitoneal AA solutions on carbamylation is unclear. Thus, we first measured carbamylated albumin (C-Alb; a marker of carbamylation load) in 100 diabetic HD patients frequency-matched by age, sex, and race to 98 diabetic PD subjects from the IMPENDIA trial, which originally compared the metabolic effects of low-glucose PD solutions (incorporating icodextrin and AAs) to a control group (dextrose-only solutions). We then determined the effects of the AA-enriched PD solutions by measuring the 6-month change in C-Alb within the IMPENDIA cohort by treatment allocation (48 treated vs 50 controls). Peritoneal dialysis patients, when compared with HD patients, had higher baseline urea and higher C-Alb. Among IMPENDIA participants, there was no difference in C-Alb change in either arm, but treated subjects showed a trend towards increased carbamylation. Treated subjects also demonstrated an increase in urea, possibly explaining the carbamylation trend. In summary, carbamylation levels in PD patients appeared higher than in matched HD patients. A regimen of AA and low-glucose PD solutions did not reduce C-Alb in IMPENDIA subjects. Copyright © 2018 International Society for Peritoneal Dialysis.

Sanitation of wallboard colonized with Stachybotrys chartarum.

PubMed

Price, D L; Ahearn, D G

1999-07-01

Sections (8 cm2) of unused, nonsterile gypsum wallboard (dry wall) were inoculated with varying densities (10(4) to approximately 10(8)/ml) of conidia from 14- to 21-day cultures of Stachybotrys chartarum grown on cellulose agar. The sections were permitted to air dry and were placed into vessels with 86% or 92% RH and incubated at 22-25 degrees C for up to 12 weeks. The moisture content of the dryboard increased from near 10% to over 35%. Selected sections with confluent surface growth, mainly of S. chartarum, were obtained within 3 weeks. Sections were cleaned with a quaternary or quaternary and chlorine dioxide or a concentrated oxygen-saline solution and treated, in some cases, with a preservative system and returned to humidity vessels. Reemergence of S. chartarum from inoculated and treated surfaces occurred within 5 weeks only with sections treated with the quaternary alone. Other fungi, mostly species of Aspergillus, Chaetomium and Penicillium, slowly colonized (between 9-12 weeks) at least some areas of most treated surfaces and most uninoculated control surfaces. Stachybotrys chartarum was also found on several sections of uninoculated controls. Sections treated with a quaternary/acrylic and placed in a dynamic challenging chamber remained visually free of colonized fungi for over 90 days. These studies indicate that control samples of uninstalled wallboard, available from local distributors, can contain a baseline bioburden, including S. chartarum, that will colonize surfaces under high humidity conditions. Sanitation and preservation treatment of the wallboard can markedly delay regrowth of these fungi, particularly of S. chartarum.

Ecological Safety of the Internal Space of the Cattle-Breeding Facility (Cowshed)

NASA Astrophysics Data System (ADS)

Potseluev, A. A.; Nazarov, I. V.; Tolstoukhova, T. N.; Kostenko, M. V.

2018-01-01

The article emphasizes the importance of observing the ecology of the internal airspace. The factors affecting the state of the air in the internal space of the cattle-breeding facility (cowshed) are revealed. Technical and technological solutions providing for a reduction in the airspace contamination of the livestock facility are proposed. The results of investigations of a technological operation for treating skin integuments of cows with activated water are disclosed, as well as the constructive solution of a heat and power unit that ensures a change in the hydrogen index of the treated water. The justification of the efficiency of the proposed technical and technological solutions is given.

Slip stream apparatus and method for treating water in a circulating water system

DOEpatents

Cleveland, J.R.

1997-03-18

An apparatus is described for treating water in a circulating water system that has a cooling water basin which includes a slip stream conduit in flow communication with the circulating water system, a source of acid solution in flow communication with the slip stream conduit, and a decarbonator in flow communication with the slip stream conduit and the cooling water basin. In use, a slip stream of circulating water is drawn from the circulating water system into the slip stream conduit of the apparatus. The slip stream pH is lowered by contact with an acid solution provided from the source thereof. The slip stream is then passed through a decarbonator to form a treated slip stream, and the treated slip stream is returned to the cooling water basin. 4 figs.

Fabrication and characterization of jute fabrics reinforced polypropylene-based composites: effects of ionizing radiation and disaccharide (sucrose)

NASA Astrophysics Data System (ADS)

Sahadat Hossain, Md.; Uddin, Muhammad B.; Razzak, Md.; Sarwaruddin Chowdhury, A. M.; Khan, Ruhul A.

2017-12-01

Composites were prepared successfully by compression molding technique using jute fabrics (reinforcing agent) and polypropylene (matrix). Jute fabrics were treated with disaccharide (sucrose) solution and composites were fabricated with the treated fabric and polypropylene. The fiber content of the prepared composites was 40% by weight. It was found that the sucrose (2% solution) decreased the tensile strength (TS) and elongation at break about 6% and 37%, respectively, but tensile modulus and impact strength improved about 27% and 32%, respectively. When gamma radiation was applied through the untreated and treated composites the mechanical properties were improved much higher in non-treated Jute/PP-based composites than that of sucrose treated composites. For 5.0 kGy gamma dose the highest mechanical properties were observed for non-treated composites. At 5.0 kGy gamma dose the improvement of TS was 14% and 2% for non-treated and sucrose treated composites, respectively. The water uptake property of the sucrose treated composites was performed up to 10 days and composites absorbed 18% water. The functional groups of the both composites were analyzed by Fourier transform infrared spectroscopy machine. The scanning electron microscopic images of the both composites were taken for the surface and fiber adhesion analysis.

Pulsed corona discharge: the role of ozone and hydroxyl radical in aqueous pollutants oxidation.

PubMed

Preis, S; Panorel, I C; Kornev, I; Hatakka, H; Kallas, J

2013-01-01

Ozone and hydroxyl radical are the most active oxidizing species in water treated with gas-phase pulsed corona discharge (PCD). The ratio of the species dependent on the gas phase composition and treated water contact surface was the objective for the experimental research undertaken for aqueous phenol (fast reaction) and oxalic acid (slow reaction) solutions. The experiments were carried out in the reactor, where aqueous solutions showered between electrodes were treated with 100-ns pulses of 20 kV voltage and 400 A current amplitude. The role of ozone increased with increasing oxygen concentration and the oxidation reaction rate. The PCD treatment showed energy efficiency surpassing that of conventional ozonation.

Removal and recovery of metals and other materials by supported liquid membranes with strip dispersion.

PubMed

Ho, W S Winston

2003-03-01

This paper reviews recent advances in supported liquid membranes (SLMs) with strip dispersion for removal and recovery of metals including chromium, copper, zinc, and strontium; it also discusses potential applications of SLMs for removal and recovery of other materials, including cobalt and penicillin G. The technology for chromium that we developed, not only removes the Cr(VI) from about 100-1,000 ppm to less than 0.05 ppm in the treated effluent allowable for discharge or recycle, but also recovers the chromium product at a high concentration of about 20% Cr(VI) (62.3% Na(2)CrO(4)) suitable for resale or reuse. In other words, we have achieved the goals of zero discharge and no sludge. The stability of the SLM is ensured by a modified SLM with strip dispersion, where the aqueous strip solution is dispersed in the organic membrane solution in a mixer. The strip dispersion formed is circulated from the mixer to the membrane module to provide a constant supply of the organic solution to the membrane pores. The copper SLM system that we have identified, not only removed the copper from 150 ppm in the inlet feed to less than 0.15 ppm in the treated feed, but also recovered the copper at a high concentration of greater than 10,000 ppm in the strip solution. For the zinc SLM system identified, zinc at an inlet feed concentration of 550 ppm was removed to less than 0.3 ppm in the treated feed, whereas a high zinc concentration of more than 17,000 ppm was recovered in the strip solution. For strontium removal, we synthesized a family of new extractants, alkyl phenylphosphonic acids. The SLM removed radioactive (90)Sr to the target of 8 pCi/L or lower from feed solutions of 300-1,000 pCi/L. The SLM removed cobalt from about 525 ppm to 0.7 ppm in the treated feed solution, concentrating it to at least 30,000 ppm in the aqueous strip solution. Concerning penicillin G recovery, the SLM removed penicillin G from a feed of 8,840 ppm and concentrated it to a high concentration of 41,011 ppm in the aqueous strip solution with a high recovery of about 93%.

Multi objective genetic algorithm to optimize the local heat treatment of a hardenable aluminum alloy

NASA Astrophysics Data System (ADS)

Piccininni, A.; Palumbo, G.; Franco, A. Lo; Sorgente, D.; Tricarico, L.; Russello, G.

2018-05-01

The continuous research for lightweight components for transport applications to reduce the harmful emissions drives the attention to the light alloys as in the case of Aluminium (Al) alloys, capable to combine low density with high values of the strength-to-weight ratio. Such advantages are partially counterbalanced by the poor formability at room temperature. A viable solution is to adopt a localized heat treatment by laser of the blank before the forming process to obtain a tailored distribution of material properties so that the blank can be formed at room temperature by means of conventional press machines. Such an approach has been extensively investigated for age hardenable alloys, but in the present work the attention is focused on the 5000 series; in particular, the optimization of the deep drawing process of the alloy AA5754 H32 is proposed through a numerical/experimental approach. A preliminary investigation was necessary to correctly tune the laser parameters (focus length, spot dimension) to effectively obtain the annealed state. Optimal process parameters were then obtained coupling a 2D FE model with an optimization platform managed by a multi-objective genetic algorithm. The optimal solution (i.e. able to maximize the LDR) in terms of blankholder force and extent of the annealed region was thus evaluated and validated through experimental trials. A good matching between experimental and numerical results was found. The optimal solution allowed to obtain an LDR of the locally heat treated blank larger than the one of the material either in the wrought condition (H32) either in the annealed condition (H111).