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Sample records for monophase solution technique

  1. A Single Step Impression Technique of Flabby Ridges Using Monophase Polyvinylsiloxane Material: A Case Report

    PubMed Central

    Pai, Umesh Y.; Reddy, Vikram Simha; Hosi, Rushad Nariman

    2014-01-01

    Complete denture fabrication in clinically compromised situations such as flabby ridges is a challenging task for the clinician. Accurate impressioning of these tissues plays a major role in ensuring a well-fitting prosthesis. In this paper, the authors have proposed a newer technique of impression making of the flabby tissues using a combination of readily available newer and older materials to ensure an accurate and easy impression of these tissues. PMID:24872897

  2. Monophasic zircon-type tetragonal Eu{sub 1−x}Bi{sub x}VO{sub 4} solid-solution: synthesis, characterization, and optical properties

    SciTech Connect

    Yi, Juan; Zhao, Zongyan; Wang, Yu’an; Zhou, Dacheng; Ma, Chenshuo; Cao, Yuechan; Qiu, Jianbei

    2014-09-15

    Highlights: • Complete Eu{sub 1−x}Bi{sub x}VO{sub 4} with zircon-type structure was successfully synthesized. • The band gap of the samples could be adjusted and controlled by bismuth content. • Eu{sub 1−x}Bi{sub x}VO{sub 4} show strong red emission under both near UV and visible-light excitation. - Abstract: By combining the methods of co-precipitation and hydrothermal synthesis methods, the complete solid-solution of Eu{sub 1−x}Bi{sub x}VO{sub 4} with monophasic zircon-type structure was successfully synthesized. The zircon-type structure was determined by X-ray diffractometer and Raman scattering, and the optical properties were characterized by ultraviolet-visible diffuse reflectance and photoluminescence spectrophotometer. The results indicate that the band gap of Eu{sub 1−x}Bi{sub x}VO{sub 4} could be adjusted and controlled by bismuth content in the range of x = 0–0.9. Meanwhile, the Eu{sub 1−x}Bi{sub x}VO{sub 4} solid-solution phosphors show strong red light emission was shown in 619 nm under both near UV-light and visible-light excitation. Notably, the emission intensity of Eu{sub 1−x}Bi{sub x}VO{sub 4} (x = 0.4) is the strongest in all samples.

  3. Primary pulmonary monophasic synovial sarcoma: Evading diagnosis.

    PubMed

    Taylor, Marcus; Srinivasan, Lakshmi; Abid, Qamar

    2016-02-01

    Primary pulmonary synovial sarcoma is a very rare tumor, thus there is no consensus as to the most appropriate management. A 78-year-old man presented with nonspecific symptoms of weight loss and shortness of breath. Imaging confirmed a large right-sided mass and accompanying pleural effusion. Strong 18F-fluorodeoxyglucose uptake was found on positron-emission tomography. The preoperative work-up and intraoperative frozen section were inconclusive. Immunohistochemistry and molecular analysis confirmed the diagnosis of primary pulmonary monophasic synovial sarcoma. PMID:26612959

  4. Techniques for Solution- Assisted Optical Contacting

    NASA Technical Reports Server (NTRS)

    DeVine, Glenn; Ware, Brent; Wuchenich, Danielle M.; Spero, Robert E.; Klipstein, William M.; McKenzie, Kirk

    2012-01-01

    A document discusses a solution-assisted contacting technique for optical contacting. An optic of surface flatness Lambda/20 was successfully contacted with one of moderate surface quality, or Lambda/4. Optics used were both ultra-low expansion (ULE) glass (Lambda/4 and Lambda/20) and fused silica (Lambda/20). A stainless steel template of the intended interferometer layout was designed and constructed with three contact points per optic. The contact points were all on a common side of the template. The entire contacting jig was tilted at about 30 . Thus, when the isopropanol was applied, each optic slid due to gravity, resting on the contact points. All of the contacting was performed in a relatively dusty laboratory. A number of successful contacts were achieved where up to two or three visible pieces of dust could be seen. These were clearly visible due to refraction patterns between the optic and bench. On a number of optics, the final step of dropping isopropyl between the surfaces was repeated until a successful contact was achieved. The new procedures realized in this work represent a simplification for optical contacting in the laboratory. They will both save time and money spent during the contacting process, and research and development phases. The techniques outlined are suitable for laboratory experiments, research, and initial development stages.

  5. Monophasic synovial sarcoma of the pharynx: a case report

    PubMed Central

    Betal, Dibendu; Babu, Ramesh; Mehmet, Veysi

    2009-01-01

    Synovial sarcomas are a rare form of soft tissue sarcomas. We present a case of a 62 year-old male presenting with a left thyroid lump initially though to be a thyroid adenoma but subsequently diagnosed as a monophasic synovial sarcoma of the pharynx. We discuss the diagnosis and treatment of this case. PMID:19335917

  6. Primary pulmonary blastoma of monophasic variety- diagnosis and management

    PubMed Central

    2013-01-01

    Pulmonary blastoma is a rare primary lung neoplasm, in that monophasic variety is far too rare. There are no specific clinical features seen for pulmonary blastoma; computed tomography and histopathology are diagnostic. Surgical excision is the treatment of choice; however, adjuvant chemotherapy and radiotherapy may be required in large and aggressive tumors. PMID:23758909

  7. Synthesis of antimicrobial monophase silver-doped hydroxyapatite nanopowders for bone tissue engineering

    NASA Astrophysics Data System (ADS)

    Stanić, Vojislav; Janaćković, Djordje; Dimitrijević, Suzana; Tanasković, Sladjana B.; Mitrić, Miodrag; Pavlović, Mirjana S.; Krstić, Aleksandra; Jovanović, Dragoljub; Raičević, Slavica

    2011-02-01

    Monophase silver-doped hydroxyapatite (AgxCa10-x(PO4)6(OH)2; 0.002 ≤ x ≤ 0.04) nanoparticles were prepared using a neutralization method and investigated with respect to potential medical applications. This method consists of dissolving Ag2O in solution of H3PO4, and the slow addition to suspension of Ca(OH)2 was applied for the purpose of homogenous distribution of silver ions. Characterization studies from XRD, TEM and FTIR spectra showed that obtained crystals are monophase hydroxyapatites and that particles of all samples are of nano size, with average length of 70 nm and about 15-25 nm in diameter. Antimicrobial studies have demonstrated that all silver-doped hydroxyapatite samples exhibit excellent antimicrobial activity in vitro against the following pathogens: Staphylococcus aureus, Escherichia coli and Candida albicans. The hydroxyapatite sample with the highest content of silver has shown the highest antimicrobial activity; killed all cells of E. coli and brought to more than 99% reduction in viable counts of S. aureus and C. albicans. The atomic force microscopic studies illustrate that silver-doped hydroxyapatite sample causes considerable morphological changes of microorganism cells which might be the cause of cells' death. Hemolysis ratios of the silver-doped hydroxyapatite samples were below 3%, indicating good blood compatibility and that are promising as biomaterials.

  8. A study of crystal growth by solution technique

    NASA Technical Reports Server (NTRS)

    Lal, R. B.

    1981-01-01

    The mechanism of crystal growth by solution technique was studied. A low temperature solution crystal growth setup was developed. Crystals of triglycine sulfate (TGS) were grown using this arrangement. Some additional tasks were performed toward fabrication of experiments for future space flight.

  9. Growth of triglycine sulfate (TGS) crystals by solution technique

    NASA Technical Reports Server (NTRS)

    Lal, R. B.; Kroes, R. L.; Wilcox, W. R.

    1982-01-01

    The growth of crystals from solution is greatly influenced by buoyancy driven convection. In a low-g environment, convection is greatly suppressed and diffusion becomes the predominant mechanism for thermal and mass transport. An experiment to grow TGS crystals by solution technique during the orbital Spacelab III mission has been designed. Crystals are grown by a new and unique technique of extracting heat from the crystal through a sting. The cooling at the sting tip is responsible for the desired supersaturation near the growing crystal. Calculations indicate that the cooled sting technique for solution crystal growth is necessary in low-g to maintain a maximum growth rate of 1 mm/day. Results of groundbased work in support of the flight experiment are discussed.

  10. Monophasic teratoma of the ovarian remnant in a bitch.

    PubMed

    Rota, A; Tursi, M; Zabarino, S; Appino, S

    2013-04-01

    An exploratory laparotomy on a mixed-breed bitch of an estimated age of 5 years revealed that she had undergone ovariectomy in the past, but a cystic structure was present in the area of the right ovary and a whitish mass, approximately 3 cm in diameter, in the area of the left ovary. These structures were removed together with an apparently normal uterus. Histological examination of the cyst showed a thin layer of connective tissue, while the left ovarian mass revealed ovarian tissue and highly differentiated nervous tissue, confirmed through immunohistochemistry. A presumptive diagnosis of mature ovarian teratoma was made. Although teratomas generally contain recognizable elements from more than one of the three germ cell layers, they can also be monophasic, when there is only one germ layer component. Ovarian teratomas are rare in the dog and never before have been reported in an ovarian fragment. PMID:23279574

  11. [Echocardiograms of a monophasic triangular wave of the tricuspid valve].

    PubMed

    Tanimoto, M; Yamamoto, T; Makihata, S; Konishiike, A; Komasa, N; Kimura, S; Yamasaki, K; Sakuyama, K; Kawai, Y; Iwasaki, T

    1982-12-01

    The echocardiographic and clinical study was performed in six patients (three acute pulmonary embolism, one for each hypertensive cardiomyopathy, ischemic heart disease and primary pulmonary hypertension) who had a diastolic monophasic triangular pattern of the tricuspid valve echogram. Left-sided and right-sided IRT / square root R-R, ICT / square root R-R, PEP, Q-Mc and Q-Tc, and PEP / ET (IRT; isovolumic relaxation time, ICT; isovolumic contraction time, PEP; preejection time, Q-Mc or Q-Tc; interval of the Q wave of the ECG to the closing point of the mitral or tricuspid valve, and ET; ejection time) were measured from echocardiograms, and the comparisons of these parameters were made between two kinds of echogram with or without triangular pattern of the tricuspid valve. There were no significant differences in the left-sided parameters between the two kinds of echocardiograms. The mitral valve echogram showed a persistent M-shaped pattern irrespective of the pattern of the tricuspid valve. Right-sided IRT / square root R-R and ICT / square root R-R were significantly prolonged and Q-Tc was significantly shortened in the echogram with a triangular pattern of the tricuspid valve. Right ventricular (RV) catheterization was performed using a Swan-Ganz catheter in four patients with the triangular pattern of the tricuspid valve echogram. The mean pulmonary artery pressure ranged from 24 to 96 mmHg (40 mmHg on an average) and RV end-diastolic pressure from 8 to 17 mmHg (12 mmHg on An average). The possible explanation for the production of the triangular tricuspid valve echogram was an impaired early diastolic relaxation and increased stiffness of the RV due to the acute pressure overloading, resulting in a delayed opening and an early closing of the tricuspid valve. We conclude that a diastolic monophasic triangular pattern of the tricuspid valve echogram is a reflection of an impaired early diastolic relaxation and an increased end-diastolic stiffness of the RV

  12. Development of solution techniques for nonlinear structural analysis

    NASA Technical Reports Server (NTRS)

    Vos, R. G.; Andrews, J. S.

    1974-01-01

    Nonlinear structural solution methods in the current research literature are classified according to order of the solution scheme, and it is shown that the analytical tools for these methods are uniformly derivable by perturbation techniques. A new perturbation formulation is developed for treating an arbitrary nonlinear material, in terms of a finite-difference generated stress-strain expansion. Nonlinear geometric effects are included in an explicit manner by appropriate definition of an applicable strain tensor. A new finite-element pilot computer program PANES (Program for Analysis of Nonlinear Equilibrium and Stability) is presented for treatment of problems involving material and geometric nonlinearities, as well as certain forms on nonconservative loading.

  13. Efficient solution techniques for simulation nutrient uptake by plant roots

    NASA Astrophysics Data System (ADS)

    Abesha, Betiglu; Vanderborght, Jan; Javaux, Mathieu; Schnepf, Andrea; Vereecken, Harry

    2015-04-01

    Water and nutrient transfer to plant roots is determined by processes occurring from the single root to the entire root system. A mechanistic spatially distributed description of these processes would require a sub mm discretization which is computationally not feasible. In this contribution, we present efficient solution techniques to represent accurate nutrient uptake by plant roots. The first solution technique describes nutrient transport towards a single root segment using a 1-D radially axisymmetric model (Barber and Cushman 1981). Transport to the entire root system is represented by a network of connected cylindrical models around the roots. This network of cylinders was coupled to a 3-D regular grid that was used to solve the flow and transport equations in the soil at the root system scale (Javaux et al. 2008). The second technique was a modified time compression approximation (TCA), which can be a simple and reasonably accurate semi-analytical method for predicting cumulative nutrient uptake when the convection flux and diffusion coefficient change over time due to for instance soil drying. The analytical approach presented by Roose et al. (2001) to calculate solute cumulative uptake provides means to analyze cumulative nutrient uptake at a changing diffusive-convective flux over time but with constant convection and diffusion coefficient. This analytical solution was used in TCA framework to predict uptake when convection and diffusion coefficient change over time. We compared cumulative nutrient uptake by the 1D / 3D coupled model with results obtained by spatially highly resolved 3-D model and the approximate analytical solution of Roose et al. (2001). The good agreement between both model approaches allows the use of the 1D/3D coupling approach to simulate water and nutrient transport at the a root system scale with minimal computational cost and good accuracy. This approach also accounts for the effect of transpiration and soil drying on nutrient

  14. A comparison of solute-transport solution techniques based on inverse modelling results

    USGS Publications Warehouse

    Mehl, S.; Hill, M.C.

    2000-01-01

    Five common numerical techniques (finite difference, predictor-corrector, total-variation-diminishing, method-of-characteristics, and modified-method-of-characteristics) were tested using simulations of a controlled conservative tracer-test experiment through a heterogeneous, two-dimensional sand tank. The experimental facility was constructed using randomly distributed homogeneous blocks of five sand types. This experimental model provides an outstanding opportunity to compare the solution techniques because of the heterogeneous hydraulic conductivity distribution of known structure, and the availability of detailed measurements with which to compare simulated concentrations. The present work uses this opportunity to investigate how three common types of results-simulated breakthrough curves, sensitivity analysis, and calibrated parameter values-change in this heterogeneous situation, given the different methods of simulating solute transport. The results show that simulated peak concentrations, even at very fine grid spacings, varied because of different amounts of numerical dispersion. Sensitivity analysis results were robust in that they were independent of the solution technique. They revealed extreme correlation between hydraulic conductivity and porosity, and that the breakthrough curve data did not provide enough information about the dispersivities to estimate individual values for the five sands. However, estimated hydraulic conductivity values are significantly influenced by both the large possible variations in model dispersion and the amount of numerical dispersion present in the solution technique.Five common numerical techniques (finite difference, predictor-corrector, total-variation-diminishing, method-of-characteristics, and modified-method-of-characteristics) were tested using simulations of a controlled conservative tracer-test experiment through a heterogeneous, two-dimensional sand tank. The experimental facility was constructed using randomly

  15. Real time solution of parameterised problems via Model Reduction techniques

    NASA Astrophysics Data System (ADS)

    Zlotnik, Sergio; Signorini, Marianna; Modesto, David

    2016-04-01

    Parameterised problems, in which the solution depends on space, time and a set of predefined parameters (e.g. material properties, boundary conditions, domain geometry, initial conditions, ...), can be solved with extremely high efficiency with Model Reduction techniques. Among these techniques the Proper Generalized Decomposition (PGD), has some very interesting features that will be investigated and presented in this work. The PGD technique involves two computational phases: first, one "offline" phase that can be computationally expensive but it is executed only once in a lifetime and, second, an "online" phase that is extremely fast and lightweight in computer resources. The possibilities of PGD are shown here via several example problems: i) heat transport parameterised in the material properties, boundary conditions and interface locations, ii) Stokes flow parameterised in the geometry domain, and iii) wave propagation parameterised in boundary conditions, material properties and interface locations. The extremely fast evaluation of PGD-solutions make them ideal to be used within inverse problems where the unknowns are the values of the parameters and the data consist in some partial observation of the solution field.

  16. Multigrid techniques for the numerical solution of the diffusion equation

    NASA Technical Reports Server (NTRS)

    Phillips, R. E.; Schmidt, F. W.

    1984-01-01

    An accurate numerical solution of diffusion problems containing large local gradients can be obtained with a significant reduction in computational time by using a multigrid computational scheme. The spatial domain is covered with sets of uniform square grids of different sizes. The finer grid patterns overlap the coarse grid patterns. The finite-difference expressions for each grid pattern are solved independently by iterative techniques. Two interpolation methods were used to establish the values of the potential function on the fine grid boundaries with information obtained from the coarse grid solution. The accuracy and computational requirements for solving a test problem by a simple multigrid and a multilevel-multigrid method were compared. The multilevel-multigrid method combined with a Taylor series interpolation scheme was found to be best.

  17. New discretization and solution techniques for incompressible viscous flow problems

    NASA Technical Reports Server (NTRS)

    Gunzburger, M. D.; Nicolaides, R. A.; Liu, C. H.

    1983-01-01

    Several topics arising in the finite element solution of the incompressible Navier-Stokes equations are considered. Specifically, the question of choosing finite element velocity/pressure spaces is addressed, particularly from the viewpoint of achieving stable discretizations leading to convergent pressure approximations. The role of artificial viscosity in viscous flow calculations is studied, emphasizing work by several researchers for the anisotropic case. The last section treats the problem of solving the nonlinear systems of equations which arise from the discretization. Time marching methods and classical iterative techniques, as well as some modifications are mentioned.

  18. Obesity prevention: Comparison of techniques and potential solution

    NASA Astrophysics Data System (ADS)

    Zulkepli, Jafri; Abidin, Norhaslinda Zainal; Zaibidi, Nerda Zura

    2014-12-01

    Over the years, obesity prevention has been a broadly studied subject by both academicians and practitioners. It is one of the most serious public health issue as it can cause numerous chronic health and psychosocial problems. Research is needed to suggest a population-based strategy for obesity prevention. In the academic environment, the importance of obesity prevention has triggered various problem solving approaches. A good obesity prevention model, should comprehend and cater all complex and dynamics issues. Hence, the main purpose of this paper is to discuss the qualitative and quantitative approaches on obesity prevention study and to provide an extensive literature review on various recent modelling techniques for obesity prevention. Based on these literatures, the comparison of both quantitative and qualitative approahes are highlighted and the justification on the used of system dynamics technique to solve the population of obesity is discussed. Lastly, a potential framework solution based on system dynamics modelling is proposed.

  19. A Solution Adaptive Technique Using Tetrahedral Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Pirzadeh, Shahyar Z.

    2000-01-01

    An adaptive unstructured grid refinement technique has been developed and successfully applied to several three dimensional inviscid flow test cases. The method is based on a combination of surface mesh subdivision and local remeshing of the volume grid Simple functions of flow quantities are employed to detect dominant features of the flowfield The method is designed for modular coupling with various error/feature analyzers and flow solvers. Several steady-state, inviscid flow test cases are presented to demonstrate the applicability of the method for solving practical three-dimensional problems. In all cases, accurate solutions featuring complex, nonlinear flow phenomena such as shock waves and vortices have been generated automatically and efficiently.

  20. Improved parallel solution techniques for the integral transport matrix method

    SciTech Connect

    Zerr, Robert J; Azmy, Yousry Y

    2010-11-23

    Alternative solution strategies to the parallel block Jacobi (PBJ) method for the solution of the global problem with the integral transport matrix method operators have been designed and tested. The most straightforward improvement to the Jacobi iterative method is the Gauss-Seidel alternative. The parallel red-black Gauss-Seidel (PGS) algorithm can improve on the number of iterations and reduce work per iteration by applying an alternating red-black color-set to the subdomains and assigning multiple sub-domains per processor. A parallel GMRES(m) method was implemented as an alternative to stationary iterations. Computational results show that the PGS method can improve on the PBJ method execution by up to {approx}50% when eight sub-domains per processor are used. However, compared to traditional source iterations with diffusion synthetic acceleration, it is still approximately an order of magnitude slower. The best-performing case are opticaUy thick because sub-domains decouple, yielding faster convergence. Further tests revealed that 64 sub-domains per processor was the best performing level of sub-domain division. An acceleration technique that improves the convergence rate would greatly improve the ITMM. The GMRES(m) method with a diagonal block preconditioner consumes approximately the same time as the PBJ solver but could be improved by an as yet undeveloped, more efficient preconditioner.

  1. Microevolution of Monophasic Salmonella Typhimurium during Epidemic, United Kingdom, 2005–2010

    PubMed Central

    Petrovska, Liljana; Mather, Alison E.; AbuOun, Manal; Branchu, Priscilla; Harris, Simon R.; Connor, Thomas; Hopkins, K.L.; Underwood, A.; Lettini, Antonia A.; Page, Andrew; Bagnall, Mary; Wain, John; Parkhill, Julian; Dougan, Gordon; Davies, Robert

    2016-01-01

    Microevolution associated with emergence and expansion of new epidemic clones of bacterial pathogens holds the key to epidemiologic success. To determine microevolution associated with monophasic Salmonella Typhimurium during an epidemic, we performed comparative whole-genome sequencing and phylogenomic analysis of isolates from the United Kingdom and Italy during 2005–2012. These isolates formed a single clade distinct from recent monophasic epidemic clones previously described from North America and Spain. The UK monophasic epidemic clones showed a novel genomic island encoding resistance to heavy metals and a composite transposon encoding antimicrobial drug resistance genes not present in other Salmonella Typhimurium isolates, which may have contributed to epidemiologic success. A remarkable amount of genotypic variation accumulated during clonal expansion that occurred during the epidemic, including multiple independent acquisitions of a novel prophage carrying the sopE gene and multiple deletion events affecting the phase II flagellin locus. This high level of microevolution may affect antigenicity, pathogenicity, and transmission. PMID:26982594

  2. Microevolution of Monophasic Salmonella Typhimurium during Epidemic, United Kingdom, 2005-2010.

    PubMed

    Petrovska, Liljana; Mather, Alison E; AbuOun, Manal; Branchu, Priscilla; Harris, Simon R; Connor, Thomas; Hopkins, K L; Underwood, A; Lettini, Antonia A; Page, Andrew; Bagnall, Mary; Wain, John; Parkhill, Julian; Dougan, Gordon; Davies, Robert; Kingsley, Robert A

    2016-04-01

    Microevolution associated with emergence and expansion of new epidemic clones of bacterial pathogens holds the key to epidemiologic success. To determine microevolution associated with monophasic Salmonella Typhimurium during an epidemic, we performed comparative whole-genome sequencing and phylogenomic analysis of isolates from the United Kingdom and Italy during 2005-2012. These isolates formed a single clade distinct from recent monophasic epidemic clones previously described from North America and Spain. The UK monophasic epidemic clones showed a novel genomic island encoding resistance to heavy metals and a composite transposon encoding antimicrobial drug resistance genes not present in other Salmonella Typhimurium isolates, which may have contributed to epidemiologic success. A remarkable amount of genotypic variation accumulated during clonal expansion that occurred during the epidemic, including multiple independent acquisitions of a novel prophage carrying the sopE gene and multiple deletion events affecting the phase II flagellin locus. This high level of microevolution may affect antigenicity, pathogenicity, and transmission. PMID:26982594

  3. Advanced techniques in reliability model representation and solution

    NASA Technical Reports Server (NTRS)

    Palumbo, Daniel L.; Nicol, David M.

    1992-01-01

    The current tendency of flight control system designs is towards increased integration of applications and increased distribution of computational elements. The reliability analysis of such systems is difficult because subsystem interactions are increasingly interdependent. Researchers at NASA Langley Research Center have been working for several years to extend the capability of Markov modeling techniques to address these problems. This effort has been focused in the areas of increased model abstraction and increased computational capability. The reliability model generator (RMG) is a software tool that uses as input a graphical object-oriented block diagram of the system. RMG uses a failure-effects algorithm to produce the reliability model from the graphical description. The ASSURE software tool is a parallel processing program that uses the semi-Markov unreliability range evaluator (SURE) solution technique and the abstract semi-Markov specification interface to the SURE tool (ASSIST) modeling language. A failure modes-effects simulation is used by ASSURE. These tools were used to analyze a significant portion of a complex flight control system. The successful combination of the power of graphical representation, automated model generation, and parallel computation leads to the conclusion that distributed fault-tolerant system architectures can now be analyzed.

  4. General solution technique for transient thermoelasticity of transversely isotropic solids in Cartesian coordinates

    NASA Astrophysics Data System (ADS)

    Noda, N.; Ashida, F.; Okumura, I. A.

    1992-07-01

    In the present paper we propose a new general solution technique for transient thermoelastic problems of transversely isotropic solids in Cartesian coordinates. The solution technique consists of five fundamental solutions. By considering the relations among the material constants of transverse isotropy, the solution technique is classified into five groups. One among those corresponds to Goodier's thermoelastic potential function as well as the generalized Boussinesq solutions and the Michell function. For an application of the solution technique, an inverse problem of transient thermoelasticity in a transversely isotropic semi-infinite solid is analyzed.

  5. The use of micellar solutions for novel separation techniques

    SciTech Connect

    Roberts, B.L.

    1993-12-31

    Surfactant based separation techniques based on the solubilization of organic compounds into the nonpolar interior of a micelle or electrostatic attraction of ionized metals and metal complexes to the charged surface of a micelle were studied in this work. Micellar solutions were used to recover two model volatile organic compounds emitted by the printing and painting industries (toluene and amyl acetate) and to investigate the effect of the most important variables in the surfactant enhanced carbon regeneration (SECR) process. SECR for liquid phase applications was also investigated in which the equilibrium adsorption of cetyl pyridinium chloride (CPC) and sodium dodecyl sulfate (SDS) on activated carbon were measured. Micellar-enhanced ultrafiltration (MEUF) was investigated using spiral wound membranes for the simultaneous removal of organic compounds, metals and metal complexes dissolved in water, with emphasis on pollution control applications. Investigations of MEUF to remove 99+ per cent of trichloroethylene (TCE) from contaminated groundwater using criteria such as: membrane flux, solubilization equilibrium constant, surfactant molecular weight, and Krafft temperature led to the selection of an anionic disulfonate with a molecular weight of 642 (DOWFAX 8390). These data and results from supporting experiments were used to design a system which could clean-up water in a 100,000 gallon/day operation. A four stage process was found to be an effective design and estimated cost for such an operation were found to be in the range of the cost of mature competitive technologies.

  6. Using Fluorescent Dyes to Demonstrate Solution-Mixing Techniques.

    ERIC Educational Resources Information Center

    Shmaefsky, Brian; Shmaefsky, Mary Jo

    1994-01-01

    Describes a demonstration using a variety of clear solutions in which the instructor asks students whether the solutions appear homogeneous or inadequately mixed. The solutions are then induced to fluoresce with ultraviolet light to provide visible evidence of homogeneity or nonhomogeneity. (PR)

  7. Solution of linear systems by a singular perturbation technique

    NASA Technical Reports Server (NTRS)

    Ardema, M. D.

    1976-01-01

    An approximate solution is obtained for a singularly perturbed system of initial valued, time invariant, linear differential equations with multiple boundary layers. Conditions are stated under which the approximate solution converges uniformly to the exact solution as the perturbation parameter tends to zero. The solution is obtained by the method of matched asymptotic expansions. Use of the results for obtaining approximate solutions of general linear systems is discussed. An example is considered to illustrate the method and it is shown that the formulas derived give a readily computed uniform approximation.

  8. Techniques for correcting approximate finite difference solutions. [considering transonic flow

    NASA Technical Reports Server (NTRS)

    Nixon, D.

    1978-01-01

    A method of correcting finite-difference solutions for the effect of truncation error or the use of an approximate basic equation is presented. Applications to transonic flow problems are described and examples are given.

  9. A hybrid explicit solution technique for quasi-static transients

    SciTech Connect

    Sauve, R.G.; Metzger, D.R.

    1996-12-01

    In certain instances, such as in the modeling of manufacturing process, undesirable dynamic effects may accompany the use of an explicit transient solution, while the use of full dynamic relaxation is inefficient for this class of problem due to critical damping. In this paper, an approach that merges the salient features of dynamic relaxation with those of the fully explicit solution, is presented. The key objective of the method is the removal of unwanted dynamic (e.g., inertial) effects, while providing for a transient kinematic loading history. This work focuses on the development of an adaptive mass algorithm consistent with specified damping and time step for use within the framework of explicit time integration. The paper describes the hybrid solution formulation and the implementation of the proposed algorithm. Applications include an experimental punch test used for material characterization and a rolled joint expansion manufacturing process used for installation of tubes in steam generators, both involving three-dimensional finite deformation.

  10. Shock-induced termination of reentrant cardiac arrhythmias: Comparing monophasic and biphasic shock protocols

    SciTech Connect

    Bragard, Jean Simic, Ana; Elorza, Jorge; Grigoriev, Roman O.; Fenton, Flavio H.; Cherry, Elizabeth M.; Gilmour, Robert F.; Otani, Niels F.

    2013-12-15

    In this article, we compare quantitatively the efficiency of three different protocols commonly used in commercial defibrillators. These are based on monophasic and both symmetric and asymmetric biphasic shocks. A numerical one–dimensional model of cardiac tissue using the bidomain formulation is used in order to test the different protocols. In particular, we performed a total of 4.8 × 10{sup 6} simulations by varying shock waveform, shock energy, initial conditions, and heterogeneity in internal electrical conductivity. Whenever the shock successfully removed the reentrant dynamics in the tissue, we classified the mechanism. The analysis of the numerical data shows that biphasic shocks are significantly more efficient (by about 25%) than the corresponding monophasic ones. We determine that the increase in efficiency of the biphasic shocks can be explained by the higher proportion of newly excited tissue through the mechanism of direct activation.

  11. Shock-induced termination of reentrant cardiac arrhythmias: Comparing monophasic and biphasic shock protocols

    NASA Astrophysics Data System (ADS)

    Bragard, Jean; Simic, Ana; Elorza, Jorge; Grigoriev, Roman O.; Cherry, Elizabeth M.; Gilmour, Robert F.; Otani, Niels F.; Fenton, Flavio H.

    2013-12-01

    In this article, we compare quantitatively the efficiency of three different protocols commonly used in commercial defibrillators. These are based on monophasic and both symmetric and asymmetric biphasic shocks. A numerical one-dimensional model of cardiac tissue using the bidomain formulation is used in order to test the different protocols. In particular, we performed a total of 4.8 × 106 simulations by varying shock waveform, shock energy, initial conditions, and heterogeneity in internal electrical conductivity. Whenever the shock successfully removed the reentrant dynamics in the tissue, we classified the mechanism. The analysis of the numerical data shows that biphasic shocks are significantly more efficient (by about 25%) than the corresponding monophasic ones. We determine that the increase in efficiency of the biphasic shocks can be explained by the higher proportion of newly excited tissue through the mechanism of direct activation.

  12. Aquatic acetylene-reduction techniques: solutions to several problems.

    PubMed

    Flett, R J; Hamilton, R D; Campbell, N E

    1976-01-01

    Previous methods of performing aquatic acetylene-reduction assays are described and several problems associated with them are discussed. A refinement of these older techniques is introduced and problems that it overcomes are also discussed. A depth profile of nitrogen fixation (C2H4 production), obtained by the refined technique, is shown for a fertilized Canadian Shield lake in the Experimental Lakes Area of northwestern Ontario. PMID:814983

  13. Monophasic and Biphasic Electrical Stimulation Induces a Precardiac Differentiation in Progenitor Cells Isolated from Human Heart

    PubMed Central

    Pietronave, Stefano; Zamperone, Andrea; Oltolina, Francesca; Colangelo, Donato; Follenzi, Antonia; Novelli, Eugenio; Diena, Marco; Pavesi, Andrea; Consolo, Filippo; Fiore, Gianfranco Beniamino; Soncini, Monica

    2014-01-01

    Electrical stimulation (ES) of cells has been shown to induce a variety of responses, such as cytoskeleton rearrangements, migration, proliferation, and differentiation. In this study, we have investigated whether monophasic and biphasic pulsed ES could exert any effect on the proliferation and differentiation of human cardiac progenitor cells (hCPCs) isolated from human heart fragments. Cells were cultured under continuous exposure to monophasic or biphasic ES with fixed cycles for 1 or 3 days. Results indicate that neither stimulation protocol affected cell viability, while the cell shape became more elongated and reoriented more perpendicular to the electric field direction. Moreover, the biphasic ES clearly induced the upregulation of early cardiac transcription factors, MEF2D, GATA-4, and Nkx2.5, as well as the de novo expression of the late cardiac sarcomeric proteins, troponin T, cardiac alpha actinin, and SERCA 2a. Both treatments increased the expression of connexin 43 and its relocation to the cell membrane, but biphasic ES was faster and more effective. Finally, when hCPCs were exposed to both monophasic and biphasic ES, they expressed de novo the mRNA of the voltage-dependent calcium channel Cav 3.1(α1G) subunit, which is peculiar of the developing heart. Taken together, these results show that ES alone is able to set the conditions for early differentiation of adult hCPCs toward a cardiac phenotype. PMID:24328510

  14. Compressible seal flow analysis using the finite element method with Galerkin solution technique

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1974-01-01

    A finite element method with a Galerkin solution (FEMGS) technique is formulated for the solution of nonlinear problems in high-pressure compressible seal flow analyses. An example of a three-dimensional axisymmetric flow having nonlinearities, due to compressibility, area expansion, and convective inertia, is used for illustrating the application of the technique.

  15. Experimental techniques for determination of the role of diffusion and convection in crystal growth from solution

    NASA Technical Reports Server (NTRS)

    Zefiro, L.

    1980-01-01

    Various studies of the concentration of the solution around a growing crystal using interferometric techniques are reviewed. A holographic interferometric technique used in laboratory experiments shows that a simple description of the solution based on the assumption of a purely diffusive mechanism appears inadequate since the convection, effective even in reduced columns, always affects the growth.

  16. Solution of electromagnetic scattering problems using time domain techniques

    NASA Technical Reports Server (NTRS)

    Britt, Charles L.

    1989-01-01

    New methods are developed to calculate the electromagnetic diffraction or scattering characteristics of objects of arbitrary material and shape. The methods extend the efforts of previous researchers in the use of finite-difference and pulse response techniques. Examples are given of the scattering from infinite conducting and nonconducting cylinders, open channel, sphere, cone, cone sphere, coated disk, open boxes, and open and closed finite cylinders with axially incident waves.

  17. Development and evaluation of an inverse solution technique for studying helicopter maneuverability and agility

    NASA Technical Reports Server (NTRS)

    Whalley, Matthew S.

    1991-01-01

    An inverse solution technique for determining the maximum maneuvering performance of a helicopter using smooth, pilotlike control inputs is presented. Also described is a pilot simulation experiment performed to investigate the accuracy of the solution resulting from this technique. The maneuverability and agility capability of the helicopter math model was varied by varying the pitch and roll damping, the maximum pitch and roll rate, and the maximum load-factor capability. Three maneuvers were investigated: a 180-deg turn, a longitudinal pop-up, and a lateral jink. The inverse solution technique yielded accurate predictions of pilot-in-the-loop maneuvering performance for two of the three maneuvers.

  18. Monophasic action potential recordings during acute changes in ventricular loading induced by the Valsalva manoeuvre.

    PubMed Central

    Taggart, P; Sutton, P; John, R; Lab, M; Swanton, H

    1992-01-01

    OBJECTIVE--The strong association between ventricular arrhythmia and ventricular dysfunction is unexplained. This study was designed to investigate a mechanism by which a change in ventricular loading could alter the time course of repolarisation and hence refractoriness. A possible mechanism may be a direct effect of an altered pattern of contraction on ventricular repolarisation and hence refractoriness. This relation has been termed contraction-excitation feedback or mechano-electric feedback. METHODS--Monophasic action potentials were recorded from the left ventricular endocardium as a measure of the time course of local repolarisation. The Valsalva manoeuvre was used to change ventricular loading by increasing the intrathoracic pressure and impeding venous return, and hence reducing ventricular pressure and volume (ventricular unloading). PATIENTS--23 patients undergoing routine cardiac catheterisation procedures: seven with no angiographic evidence of abnormal wall motion or history of myocardial infarction (normal), five with a history of myocardial infarction but with normal wall motion, and 10 with angiographic evidence of abnormal wall motion--with or without previous infarction. One patient was a transplant recipient and was analysed separately. SETTING--Tertiary referral centre for cardiology. RESULTS--In patients with normal ventricles during the unloading phase of the Valsalva manoeuvre (mean (SD)) monophasic action potential duration shortened from 311 (47) ms to 295 (47) ms (p less than 0.001). After release of the forced expiration as venous return was restored the monophasic action potential duration lengthened from 285 (44) ms to 304 (44) ms (p less than 0.0001). In the group with evidence of abnormal wall motion the direction of change of action potential duration during the strain phase was normal in 7/21 observations, abnormal in 6/21, and showed no clear change in 8/21. During the release phase 11/20 observations were normal, five abnormal

  19. Improvement of tear trough by monophasic hyaluronic Acid and calcium hydroxylapatite.

    PubMed

    Wollina, Uwe

    2014-10-01

    Tear trough deformities are a sign of facial aging. The anatomical base is well understood. In many patients, minimal invasive surgical procedures are useful to improve appearance. Here, the authors describe the use of monophasic hyaluronic acid dermal filler and calcium hydroxylapatite injection for correction. Forty female patients with a mean age of 50 years have been treated. On average, an improvement of one class of Hidman's severity score could be achieved by single treatment. Mean duration of the effect was 10.1 months for hyaluronic acid and 12.8 months for calcium hydroxylapatite. Adverse effects were mild and temporary. Patients satisfaction was high (95%). PMID:25371770

  20. A comparison of solute-transport solution techniques and their effect on sensitivity analysis and inverse modeling results

    USGS Publications Warehouse

    Mehl, S.; Hill, M.C.

    2001-01-01

    Five common numerical techniques for solving the advection-dispersion equation (finite difference, predictor corrector, total variation diminishing, method of characteristics, and modified method of characteristics) were tested using simulations of a controlled conservative tracer-test experiment through a heterogeneous, two-dimensional sand tank. The experimental facility was constructed using discrete, randomly distributed, homogeneous blocks of five sand types. This experimental model provides an opportunity to compare the solution techniques: the heterogeneous hydraulic-conductivity distribution of known structure can be accurately represented by a numerical model, and detailed measurements can be compared with simulated concentrations and total flow through the tank. The present work uses this opportunity to investigate how three common types of results - simulated breakthrough curves, sensitivity analysis, and calibrated parameter values - change in this heterogeneous situation given the different methods of simulating solute transport. The breakthrough curves show that simulated peak concentrations, even at very fine grid spacings, varied between the techniques because of different amounts of numerical dispersion. Sensitivity-analysis results revealed: (1) a high correlation between hydraulic conductivity and porosity given the concentration and flow observations used, so that both could not be estimated; and (2) that the breakthrough curve data did not provide enough information to estimate individual values of dispersivity for the five sands. This study demonstrates that the choice of assigned dispersivity and the amount of numerical dispersion present in the solution technique influence estimated hydraulic conductivity values to a surprising degree.

  1. A Tumour in Disguise in the Right Palm- Monophasic Synovial Sarcoma

    PubMed Central

    Arumugam, Vasugi Gramani; Ramesh, Anita; Duvuru, Prathiba; Rajappa, Srinivasa

    2016-01-01

    Synovial sarcoma is one of the poorly differentiated malignant soft tissue tumour occuring commonly among young adults in the extremities. We report a 50-year-old female presenting with a soft tissue mass in the right palm. On examination, a single firm and non tender swelling was noticed adjacent to the thenar muscles. Radiology suggested a benign soft tissue lesion. The swelling, clinically thought to be a lipoma, was excised and sent for histopathological examination. Microscopy showed a highly cellular tumour arranged in nests, cords and pseudo glandular pattern separated by dense fibrocollagenous tissue. An interesting and baffling finding was the presence of a distinct mucin vacuole in many of the tumour cells. A diagnosis of soft tissue sarcoma with epithelial features was considered and a panel of immunohistochemical stains done. Tumour cells showed strong positivity for cytokeratin 7, vimentin, EMA & Bcl2. CD 99 and S100 were focally positive. CD 34 and CEA were negative. In view of the above microscopic and immunohistochemical findings, a diagnosis of monophasic synovial sarcoma of epithelial type was rendered. This case is being documented for the rare morphological appearance of mucin vacuoles in a monophasic epithelial type synovial sarcoma. PMID:27437233

  2. Salivary SIgA responses to acute moderate-vigorous exercise in monophasic oral contraceptive users.

    PubMed

    Hayashida, Harumi; Dolan, Nicola J; Hounsome, Charlotte; Alajmi, Nawal; Bishop, Nicolette C

    2015-09-01

    The purpose of this study was to examine the effect of oral contraceptive (OC) use on salivary secretory immunoglobulin A (SIgA) levels at rest and in response to an acute bout of moderate-vigorous exercise during 2 phases of the 4-week OC cycle corresponding to different phases of the synthetic menstrual cycle. Ten healthy active females completed a cycling at 70% peak oxygen uptake for 45 min at 2 time points of an OC cycle: during the equivalent in time to the mid-follicular phase (day 8 ± 2) and the mid-luteal phase (day 20 ± 2). Timed unstimulated saliva samples were obtained before, immediately postexercise, and 1 h postexercise and analyzed for salivary SIgA. Salivary SIgA secretion rate was 26% (95% confidence limits (CI) 6-46) lower at postexercise compared with pre-exercise during the synthetic follicular phase (p = 0.019) but no differences were observed during the synthetic luteal trial. Saliva flow rate was 11% (95% CI, 8-30) lower at postexercise compared with pre-exercise (main effect for time; p = 0.025). In conclusion, the pattern of salivary SIgA secretion rate response to moderate-vigorous exercise varies across the early and late phases of a monophasic OC cycle, with a transient reduction in salivary SIgA responses during the synthetic follicular phase. These findings indicate that monophasic OC use should be considered when assessing mucosal immune responses to acute exercise. PMID:26300012

  3. A Tumour in Disguise in the Right Palm- Monophasic Synovial Sarcoma.

    PubMed

    Arumugam, Vasugi Gramani; Sundaram, Sandhya; Ramesh, Anita; Duvuru, Prathiba; Rajappa, Srinivasa

    2016-05-01

    Synovial sarcoma is one of the poorly differentiated malignant soft tissue tumour occuring commonly among young adults in the extremities. We report a 50-year-old female presenting with a soft tissue mass in the right palm. On examination, a single firm and non tender swelling was noticed adjacent to the thenar muscles. Radiology suggested a benign soft tissue lesion. The swelling, clinically thought to be a lipoma, was excised and sent for histopathological examination. Microscopy showed a highly cellular tumour arranged in nests, cords and pseudo glandular pattern separated by dense fibrocollagenous tissue. An interesting and baffling finding was the presence of a distinct mucin vacuole in many of the tumour cells. A diagnosis of soft tissue sarcoma with epithelial features was considered and a panel of immunohistochemical stains done. Tumour cells showed strong positivity for cytokeratin 7, vimentin, EMA & Bcl2. CD 99 and S100 were focally positive. CD 34 and CEA were negative. In view of the above microscopic and immunohistochemical findings, a diagnosis of monophasic synovial sarcoma of epithelial type was rendered. This case is being documented for the rare morphological appearance of mucin vacuoles in a monophasic epithelial type synovial sarcoma. PMID:27437233

  4. Compressible seal flow analysis using the finite element method with Galerkin solution technique

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1974-01-01

    High pressure gas sealing involves not only balancing the viscous force with the pressure gradient force but also accounting for fluid inertia--especially for choked flow. The conventional finite element method which uses a Rayleigh-Ritz solution technique is not convenient for nonlinear problems. For these problems, a finite element method with a Galerkin solution technique (FEMGST) was formulated. One example, a three-dimensional axisymmetric flow formulation has nonlinearities due to compressibility, area expansion, and convective inertia. Solutions agree with classical results in the limiting cases. The development of the choked flow velocity profile is shown.

  5. A numerical technique for obaining the complete bifurcated equilibrium solution space for a Tokamak

    SciTech Connect

    Helton, F.J.; Greene, J.M.

    1992-01-01

    This paper describes a new numerical method for finding solutions to the ideal MHD equilibrium problem The space of solutions thus found can have more than one bifurcation branch, depending on the tokamak being modeled. We suggest that the solutions which are difficult to obtain without the use of this technique correspond to equilibria which are difficult to maintain in the tokamak being modeled. First, this paper investigates, for a tokamak design with large poloidal field-shaping coil (PFC) to plasma distance, the bifurcated numerical solution curve as a function of flux loop position and relates this curve to the practical existence of ideal magnetohydrodynamic equilibria and practical tokamak design. In previous papers, some of the problems which could arise for large PFC-plasma distance were discussed. Then, using a regularization technique, it was shown that, for large PFC-plasma distance, the flux loops should be close to the PFCs for stable control if the full information form the flux loops is used. Here it is shown that, for large PFC-plasma distance, the structure of the equilibrium solution space becomes increasingly complex and desirable solutions become more difficult to attain as the flux loops are moved farther from the plasma. In order to explore this solution space numerically, it is necessary to obtain solutions for which the usual Picard iteration method is unstable. Here an extension of this method is given. The solution space is enlarged by adding additional variable and constraints, so that the iteration to the desired solution is stable in the extended space. A modified version of this numerical technique has been used to obtain equilibrium fits to highly elongated DIII-D plasmas. The numerical equilibria are very difficult to obtain without the use of this technique and the plasmas are difficult to maintain in the tokamak. 10 refs., 6 figs., 2 tabs.

  6. Increased interleukin-6 correlates with myelin oligodendrocyte glycoprotein antibodies in pediatric monophasic demyelinating diseases and multiple sclerosis.

    PubMed

    Horellou, Philippe; Wang, Min; Keo, Vixra; Chrétien, Pascale; Serguera, Ché; Waters, Patrick; Deiva, Kumaran

    2015-12-15

    Acquired demyelinating syndromes (ADS) in children evolve either as a monophasic disease diagnosed as acute demyelinating encephalomyelitis (ADEM), transverse myelitis (TM) or optic neuritis (ON), or a multiphasic one with several relapses most often leading to the diagnosis of multiple sclerosis (MS) or neuromyelitis optica (NMO). These neuroinflammatory disorders are increasingly associated with autoantibodies against proteins such as aquaporin-4 in rare instances, and more frequently against myelin oligodendrocyte glycoprotein (MOG). Recently, in adult NMO patients, C5a levels were shown to be elevated in cerebrospinal fluid (CSF) during acute exacerbation. We investigated the CSF levels of anaphylatoxins and pro-inflammatory cytokines, and plasma MOG antibodies in onset samples from children with ADS. Thirty four children presenting with a first episode of ADS, 17 with monophasic ADS (9 with ADEM, 4 with TM and 4 with ON) and 17 with MS, who had paired blood and CSF samples at onset were included and compared to 12 patients with other non-inflammatory neurological disorders (OND). Cytokines and anaphylatoxins in CSF were measured by Cytometric Bead Array immunoassay. MOG antibody titers in plasma were tested by flow cytometry using a stable cell line expressing full-length human MOG. We found a significant increase in C5a levels in the CSF of patients with monophasic ADS (n=17) compared to OND (n=12, p=0.0036) and to MS (n=17, p=0.0371). The C5a levels in MS were higher than in OND without reaching significance (p=0.2). CSF IL-6 levels were significantly increased in monophasic ADS compared to OND (p=0.0027) and to MS (p=0.0046). MOG antibody plasma levels were significantly higher in monophasic ADS (p<0.0001) and, to a lesser extent, in MS compared to OND (p=0.0023). Plasma MOG antibodies and CSF IL-6 levels were significantly correlated (r=0.51, p=0.018). CSF C5a and IL-6 levels are increased in monophasic ADS but not in MS when compared to OND, suggesting

  7. A study of crystal growth by solution technique. [triglycine sulfate single crystals

    NASA Technical Reports Server (NTRS)

    Lal, R. B.

    1979-01-01

    The advantages and mechanisms of crystal growth from solution are discussed as well as the effects of impurity adsorption on the kinetics of crystal growth. Uncertainities regarding crystal growth in a low gravity environment are examined. Single crystals of triglycine sulfate were grown using a low temperature solution technique. Small components were assembled and fabricated for future space flights. A space processing experiment proposal accepted by NASA for the Spacelab-3 mission is included.

  8. Outbreaks of monophasic Salmonella enterica serovar 4,[5],12:i:- in Luxembourg, 2006.

    PubMed

    Mossong, J; Marques, P; Ragimbeau, C; Huberty-Krau, P; Losch, S; Meyer, G; Moris, G; Strottner, C; Rabsch, W; Schneider, F

    2007-06-01

    A monophasic Salmonella enterica serovar 4,[5],12:i:- phage type DT193 emerged as the dominant serovar in Luxembourg in 2006, when it caused two major outbreaks involving 133 laboratory-confirmed human cases, 24 hospitalisations, and one death. The outbreak strain had an uncommon pulsed-field gel electrophoresis pattern STYMXB.0031 and antibiotic resistance profile ASSuT. A high proportion of cases were clustered in institutions for the elderly and in day-care centers. Strains identical to the outbreak strain were recovered from two control meals, a nappy changing table, retail sausages and caecal porcine samples at an abattoir. Locally produced pork meat is strongly suspected to have been the vehicle for the outbreaks, although the precise mechanisms remain unclear. PMID:17991400

  9. Monophasic Pulsed 200-μA Current Promotes Galvanotaxis With Polarization of Actin Filament and Integrin α2β1 in Human Dermal Fibroblasts

    PubMed Central

    Uemura, Mikiko; Maeshige, Noriaki; Koga, Yuka; Ishikawa-Aoyama, Michiko; Miyoshi, Makoto; Sugimoto, Masaharu; Terashi, Hiroto

    2016-01-01

    Objective: The monophasic pulsed microcurrent is used to promote wound healing, and galvanotaxis regulation has been reported as one of the active mechanisms in the promotion of tissue repair with monophasic pulsed microcurrent. However, the optimum monophasic pulsed microcurrent parameters and intracellular changes caused by the monophasic pulsed microcurrent have not been elucidated in human dermal fibroblasts. The purpose of this study was to investigate the optimum intensity for promoting galvanotaxis and the effects of electrical stimulation on integrin α2β1 and actin filaments in human dermal fibroblasts. Methods: Human dermal fibroblasts were treated with the monophasic pulsed microcurrent of 0, 100, 200, or 300 μA for 8 hours, and cell migration and cell viability were measured 24 hours after starting monophasic pulsed microcurrent stimulation. Polarization of integrin α2β1 and lamellipodia formation were detected by immunofluorescent staining 10 minutes after starting monophasic pulsed microcurrent stimulation. Results: The migration toward the cathode was significantly higher in the cells treated with the 200-μA monophasic pulsed microcurrent than in the controls (P < .01) without any change in cell viability; treatment with 300-μA monophasic pulsed microcurrent did not alter the migration ratio. The electrostimulus of 200 μA also promoted integrin α2β1 polarization and lamellipodia formation at the cathode edge (P < .05). Conclusion: The results show that 200 μA is an effective monophasic pulsed microcurrent intensity to promote migration toward the cathode, and this intensity could regulate polarization of migration-related intracellular factors in human dermal fibroblasts. PMID:26819649

  10. The effect of stimulation frequency on the transmural ventricular monophasic action potential in yellowfin tuna Thunnus albacares.

    PubMed

    Patrick, S M; White, E; Brill, R W; Shiels, H A

    2011-02-01

    Monophasic action potentials (MAPs) were recorded from the spongy and compact layers of the yellowfin tuna Thunnus albacares ventricle as stimulation frequency was increased. MAP duration decreased with increase in stimulation frequency in both the spongy and compact myocardial layers, but no significant difference in MAP duration was observed between the layers. PMID:21284642

  11. Longitudinal characterization of monophasic Salmonella Typhimurium throughout the pig's life cycle.

    PubMed

    Fernandes, Laura; Centeno, Maria Madalena; Couto, Natacha; Nunes, Telmo; Almeida, Virgílio; Alban, Lis; Pomba, Constança

    2016-08-30

    Swine have been described as an important reservoir of multidrug resistant monophasic Salmonella Typhimurium, though information on its ecology is scarce. A longitudinal study was performed in order to elucidate the Salmonella 4,[5],12:i:- dynamics throughout the pig's production cycle. A total of 209 faecal samples were collected from 10 sows and in six sampling times during the life of 70 pigs from a Portuguese industrial farm, and 43 isolates of S. 4,[5],12:i:- were identified and characterized regarding clonality and antimicrobial resistance phenotype and genotype. Most isolates (n=42) exhibited resistance to at least ampicillin, kanamycin, neomycin, streptomycin, tetracycline and sulfonamides (encoded by blaTEM, aphAI-IAB, strA, strB, tetB and sul2, respectively). Isolates obtained during the finishing phase showed additional resistance to chloramphenicol and florfenicol (floR), gentamicin and netilmicin (aac(3')-IV). To our knowledge, this study is the first description of aphAI-IAB in S. 4,[5],12:i:-. PFGE analysis showed uneven distribution of isolates into three clusters, A (n=34), B (n=8) and C (n=1). PFGE cluster A was predominant in sows (n=5) and piglets in the farrowing phase (n=17) and in pigs in the early finishing phase (n=11) suggesting a carryover from birth to adult age. The introduction of PFGE cluster B isolates in adulthood could have had an external source, reinforcing the relevance of environmental transmission in the farm ecosystem. This study reveals a dynamic interaction between monophasic S. Typhimurium and the pressures exerted under an intensive swine production setting. PMID:27527788

  12. A wirelessly powered electro-acupuncture based on adaptive pulsewidth monophase stimulation.

    PubMed

    Kiseok Song; Long Yan; Seulki Lee; Yoo, Jerald; Hoi-Jun Yoo

    2011-04-01

    A wirelessly powered electro-acupuncture (EA) system with adaptive-pulsewidth (APW) monophase stimulation is presented for convenient invasive medicine. The proposed system removes cumbersome wires connected between EA nodes and an EA controller in order to realize both patients' convenience and remedial values simultaneously. An ultra-low-power stimulator integrated circuit (IC) that is integrated on the flexible-printed-circuit board (F-PCB) is attached to the tip of a needle electrode. Combined with a conductive yarn helical antenna wound around the needle electrode, the EA node receives wireless power from the EA controller using 433 MHz with the maximum loss of 6 dB. A zero-Vth nMOS rectifier harvests a supply voltage of 1.0 V from a -16-dBm incoming power signal with 32% efficiency. To deal with a body impedance variation (BIV) in the range of 100-200 kΩ , the proposed APW stimulator IC, fabricated in a 0.18-μm 1P6M complementary metal-oxide semiconductor CMOS process and occupying 1.56 mm(2), enables constant charge injection of 80-nC/stimulation. To ensure the patients' safety, the EA node (a pair of EAs) shares ground and clock wires to operate in alternate monophase (AMP) fashion for neutralizing the injected charge. The proposed wirelessly powered EA node was verified by applying it to a chunk of pork as a body model with the wireless power supplied from an RF signal generator (output power of 10 dBm and located 30 cm away). PMID:23851202

  13. Problems and solutions in analyzing partial-reflection drift data by correlation techniques

    NASA Technical Reports Server (NTRS)

    Meek, C. E.

    1984-01-01

    Solutions in analyzing partial reflection drift data by correlation techniques are discussed. The problem of analyzing spaced antenna drift data breaks down into the general categories of raw data collection and storage, correlation calculation, interpretation of correlations, location of time lags for peak correlation, and velocity calculation.

  14. Revisit of well function approximation and an easy graphical curve matching technique for Theis' solution.

    PubMed

    Giao, Pham Huy

    2003-01-01

    Some approximations of Theis' solution are reviewed and compared with the numerical evaluation of the exponential integral by means of a short FORTRAN code. A graphical technique of Theis' curve matching is proposed to make this procedure as easy as plotting a graph. PMID:12772832

  15. Removal of cadmium from aqueous solution using adsorptive bubble separation techniques

    SciTech Connect

    Huang, S.D.; Wang, T.F.

    1988-08-01

    Cadmium ion was removed from aqueous solutions using adsorptive bubble separation techniques. The effect of pH, coagulant and activator concentrations and ionic strength on separation efficiency was studied. Adsorbing colloid flotation using ferric hydroxide and aluminum hydroxide as the coprecipitant and sodium lauryl sulfate as the collector and frother was found to be very effective provided that the ionic strength of the solution was no greater than 0.01 M. The residual cadmium concentration was less than 0.02 ppm after foaming for 10 min from a solution containing 20 ppm cadmium initially. Effective separation can be achieved from solutions containing 0.1 M NaNO/sub 3/ or 0.05 M Na/sub 2/SO/sub 4/ when zinc ion is used as the activator. The results of foam flotation were compared with the zeta potential of the floc. It was found that the zeta potential of the floc decreases with increasing ionic strength of the solution. The zeta potential of the floc is more positive when activators (aluminum and zinc ions) were added, which presumably gives the floc a stronger affinity for anionic surfactant adsorption, resulting in better separation efficiency. Adsorbing colloid flotation becomes less effective with increasing inert salt concentration of the solution; this effect can be compensated for to quite a large extent with the aid of activators, and the applicability of foam separation techniques for heavy metal removal from wastewater is thus greatly extended.

  16. Global analysis of GaN growth using a solution technique

    NASA Astrophysics Data System (ADS)

    Kashiwagi, D.; Gejo, R.; Kangawa, Y.; Liu, L.; Kawamura, F.; Mori, Y.; Sasaki, T.; Kakimoto, K.

    2008-04-01

    The solution growth technique is one of the key methods for fabricating gallium nitride (GaN) wafers with small dislocation density. Since the growth rate of GaN using the solution technique is small, the key issue of the technique is to enhance the growth rate of the crystal. We studied how nitrogen is transferred from the surface of the flux to the interface between the top of the flux and the crystal in a muffle furnace using a global model that includes radiative, convective and conductive heat and mass transfer, including nitrogen transfer. The average growth rate of GaN increased when the temperature difference between the furnace wall and a crucible wall became large. This phenomenon is based on mixing of the flux due to natural convection.

  17. Solution of the stochastic generalized shallow-water wave equation using RVT technique

    NASA Astrophysics Data System (ADS)

    Hussein, Abdallah; Selim, Mustafa M.

    2015-12-01

    In this paper, some exact solutions of the stochastic generalized nonlinear shallow-water wave (SGNSWW) equation are obtained. This equation is an important equation in fluid mechanics field. Opposite to what is usually assumed in the literature, the coefficients of the nonlinear terms in this stochastic nonlinear partial differential equation (SNLPDE) are considered to be random quantities. The random variable transformation (RVT) technique is combined with the modified extended-tanh function method (METFM) to get the stochastic solutions represented by the probability density functions (PDFs) of the solution processes in terms of the PDFs of the random coefficients. These solutions are illustrated graphically along the spacial and time dimensions at a certain wave speed.

  18. Reaction fronts in a porous medium. Approximation techniques versus numerical solution

    SciTech Connect

    Escobedo, F.; Viljoen, H.J.

    1995-03-01

    The combustion of a gas fuel inside a porous media, as found in radiant porous burners (PRB), is one of the most promising novel combustion concepts. The flame sheet approximation (FS) and a novel polynomial approximation technique (PA) are compared in terms of their capability to describe reaction fronts of highly exothermic reactions in a porous medium. A one-phase model and a two-phase model of a system with adiabatic walls and a radiant output (to approximate the case of a porous radiant burner) are included in the analysis. By matching the reaction zone solution found by either the FS or PA method with the solutions of the nonreacting zones, the temperature, conversion, and position of the reaction zone were determined. Numerical solutions for catalytic and noncatalytic oxidation reactions were used to compare the predictions of both approaches. It was found that although both techniques yielded good approximations to the solutions, the PA technique proved to be more accurate, producing results with 3.5% of the numerical results. Both methods can find useful application in the analysis of this class of problems.

  19. Low dosage monophasic oral contraceptive use and intermittent exercise performance and metabolism in humans.

    PubMed

    Lynch, N J; De Vito, G; Nimmo, M A

    2001-04-01

    Nine untrained women using low dosage monophasic oral contraceptives (OC) performed an intermittent treadmill test on two different occasions within one pill-cycle to determine the effect of OC on performance and some commonly used metabolic markers. The first test was performed after 5-8 days of resuming the OC agents after menstrual bleeding while the other test was performed after 19-21 days. Performance time on the final exhausting run of six intermittent high intensity 20 s runs was no different between trials [mean days 5-8: 22.3 (SEM 1.2) s vs days 19-21: 22.7 (SEM 1.1) s]. There was no difference in heart rate [peak heart rate days 5-8: 183 (SEM 3) beats.min-1 vs days 19-21: 186 (SEM 2) beats.min-1], oxygen consumption during any run [run 5 of days 5-8: 1,392 (SEM 51) ml.min-1 vs run 5 of days 19-21: 1,494 (SEM 3) ml.min-1] or in any of the metabolic variables measured at any time in venous blood [peak blood lactate concentration days 5-8: 8.4 (SEM 0.3) mmol.l-1 vs days 19-21: 8.1 (SEM 0.5) mmol.l-1; peak blood glycerol concentration days 5-8: 0.39 (SEM 0.02) mmol.l-1 vs days 19-21: 0.38 (SEM 0.02) mmol.l-1; resting free fatty acids concentration days 5-8: 0.25 (SEM 0.05) mmol.l-1 vs days 19-21: 0.29 (SEM 0.07) mmol.l-1; peak blood glucose concentration days 5-8: 6.7 (SEM 0.5) mmol.l-1 vs days 19-21: 6.6 (SEM 0.2) mmol.l-1; peak capillary blood ammonia concentration days 5-8: 139 (SEM 18.3) mumol.l-1 vs days 19-21: 170 (SEM 18.0) mumol.l-1]. These results suggest neither intermittent high intensity exercise performance nor energy metabolism change between days 5-8 and days 19-21 of a low dosage monophasic OC pill during one pill-cycle. PMID:11374113

  20. Application of implicit numerical techniques to the solution of the three-dimensional diffusion equation

    NASA Technical Reports Server (NTRS)

    Peltier, Leonard Joel; Biringen, Sedat; Chait, Arnon

    1990-01-01

    Implicit techniques for calculating three-dimensional, time-dependent heat diffusion in a cube are tested with emphasis on storage efficiency, accuracy, and speed of calculation. For this purpose, a tensor product technique with both Chebyshev collocation and finite differences and a generalized conjugate gradient technique with finite differences are used in conjunction with Crank-Nicolson discretization. An Euler explicit finite difference calculation is performed for use as a benchmark. The implicit techniques are found to be competitive with the Euler explicit method in terms of storage efficiency and speed of calculation and offer advantages both in accuracy and stability. Mesh stretching in the finite difference calculations is shown to markedly improve the accuracy of the solution.

  1. Solvent and solute ingress into hydrogels resolved by a combination of imaging techniques

    NASA Astrophysics Data System (ADS)

    Wagner, D.; Burbach, J.; Grünzweig, C.; Hartmann, S.; Lehmann, E.; Egelhaaf, S. U.; Hermes, H. E.

    2016-05-01

    Using simultaneous neutron, fluorescence, and optical brightfield transmission imaging, the diffusion of solvent, fluorescent dyes, and macromolecules into a crosslinked polyacrylamide hydrogel was investigated. This novel combination of different imaging techniques enables us to distinguish the movements of the solvent and fluorescent molecules. Additionally, the swelling or deswelling of the hydrogels can be monitored. From the sequence of images, dye and solvent concentrations were extracted spatially and temporally resolved. Diffusion equations and different boundary conditions, represented by different models, were used to quantitatively analyze the temporal evolution of these concentration profiles and to determine the diffusion coefficients of solvent and solutes. Solute size and network properties were varied and their effect was investigated. Increasing the crosslinking ratio or partially drying the hydrogel was found to hinder solute diffusion due to the reduced pore size. By contrast, solvent diffusion seemed to be slightly faster if the hydrogel was only partially swollen and hence solvent uptake enhanced.

  2. The solution of the Elrod algorithm for a dynamically loaded journal bearing using multigrid techniques

    NASA Technical Reports Server (NTRS)

    Woods, Claudia M.; Brewe, David E.

    1988-01-01

    A numerical solution to a theoretical model of vapor cavitation in a dynamically loaded journal bearing is developed utilizing a multigrid iteration technique. The method is compared with a noniterative approach in terms of computational time and accuracy. The computational model is based on the Elrod algorithm, a control volume approach to the Reynolds equation which mimics the Jakobsson-Floberg and Olsson cavitation theory. Besides accounting for a moving cavitation boundary and conservation of mass at the boundary, it also conserves mass within the cavitated region via a smeared mass or striated flow extending to both surfaces in the film gap. The mixed nature of the equations (parabolic in the full film zone and hyperbolic in the cavitated zone) coupled with the dynamic aspects of the problem create interesting difficulties for the present solution approach. Emphasis is placed on the methods found to eliminate solution instabilities. Excellent results are obtained for both accuracy and reduction of computational time.

  3. Application of Liquid Emulsion Membrane Technique for the Removal of As(V) from Aqueous Solutions

    NASA Astrophysics Data System (ADS)

    Binnal, Prakash; Hiremath, Poornima G.

    2012-08-01

    Liquid emulsion membrane technique was used to remove As(V) from synthetic aqueous solutions. The emulsion was composed of Aliquat 336 as an extractant, commercial kerosene as a diluent and Span 80 (Sorbiton monooleate) as an emulsifying agent. Different types of internal phases were used, namely, sodium hydroxide, sodium carbonate, ammonium bicarbonate, sodium sulphate and sodium chloride. The effect of process parameters affecting extraction efficiency, such as, initial concentration of As(V) in feed solution, pH of feed solution, concentrations of Aliquat 336 and Span 80 in membrane phase, volume ratio of stripping phase to membrane phase, concentration of internal phase, type of internal phase, volume ratio of emulsion to feed, agitation speed during extraction and time of extraction was investigated. The optimum conditions for the extraction were determined. A maximum As(V) removal rate of 97.8 was observed under optimum conditions.

  4. The solution of the Elrod algorithm for a dynamically loaded journal bearing using multigrid techniques

    NASA Technical Reports Server (NTRS)

    Woods, C. M.; Brewe, D. E.

    1989-01-01

    A numerical solution to a theoretical model of vapor cavitation in a dynamically loaded journal bearing is developed utilizing a multigrid iteration technique. The method is compared with a noniterative approach in terms of computational time and accuracy. The computational model is based on the Elrod algorithm, a control volume approach to the Reynolds equation which mimics the Jakobsson-Floberg and Olsson cavitation theory. Besides accounting for a moving cavitation boundary and conservation of mass at the boundary, it also conserves mass within the cavitated region via a smeared mass or striated flow extending to both surfaces in the film gap. The mixed nature of the equations (parabolic in the full film zone and hyperbolic in the cavitated zone) coupled with the dynamic aspects of the problem create interesting difficulties for the present solution approach. Emphasis is placed on the methods found to eliminate solution instabilities. Excellent results are obtained for both accuracy and reduction of computational time.

  5. Solvent and solute ingress into hydrogels resolved by a combination of imaging techniques.

    PubMed

    Wagner, D; Burbach, J; Grünzweig, C; Hartmann, S; Lehmann, E; Egelhaaf, S U; Hermes, H E

    2016-05-28

    Using simultaneous neutron, fluorescence, and optical brightfield transmission imaging, the diffusion of solvent, fluorescent dyes, and macromolecules into a crosslinked polyacrylamide hydrogel was investigated. This novel combination of different imaging techniques enables us to distinguish the movements of the solvent and fluorescent molecules. Additionally, the swelling or deswelling of the hydrogels can be monitored. From the sequence of images, dye and solvent concentrations were extracted spatially and temporally resolved. Diffusion equations and different boundary conditions, represented by different models, were used to quantitatively analyze the temporal evolution of these concentration profiles and to determine the diffusion coefficients of solvent and solutes. Solute size and network properties were varied and their effect was investigated. Increasing the crosslinking ratio or partially drying the hydrogel was found to hinder solute diffusion due to the reduced pore size. By contrast, solvent diffusion seemed to be slightly faster if the hydrogel was only partially swollen and hence solvent uptake enhanced. PMID:27250327

  6. Conductive Perovskite-type Metal Oxide Thin Films Prepared by Chemical Solution Deposition Technique

    NASA Astrophysics Data System (ADS)

    Sasajima, K.; Uchida, H.

    2011-10-01

    Metal oxide electrode have been widely developed for high-performance electric device because they possess some attractive characteristic such as thermal/chemical stabilities and change compensation for oxygen vacancies in interconnected dielectric layers, etc., which is often hardly achieved by convention metal electrodes. As almost all metal oxide electrodes were usually fabricated by some vapour deposition techniques which require large-scale equipments, power, resources and costs, film deposition via solution technique would be worthy for familiarizing the metal oxide electrodes. In this research, thin films of conductive perovskite-type oxides, (La,Sr)CoO3 [LSCO], were fabricated by chemical solution deposition technique. The precursor solution for LSCO was prepared using metal nitrate, acetates, and iso-propoxide and 2-methoxyethanol. The solution was spin-coated on substrates, followed by drying, pyrolysis and RTA-treatment for crystallization at 500-750°C, for 5 min in air. These processes were repeated to obtain desired film thickness. (100)Si and (100)SrTiO3 were used as substrate. XRD analysis indicated that both of LSCO films fabricated on (100)SrTiO3 and (100)Si substrates were crystallized at and above 600°C. The films on (100)SrTiO3 had preferential crystal orientation of (100)LSCO normal to the substrate surface, while random crystal orientation was confirmed for the films on (100)Si. Electrical resistivity of the both films fabricated at 700°C were 6.09 × 10-5 Ω cm and 1.12 × 10-4 Ω cm, respectively, which is almost same as the LSCO films fabricated by conventional vapour deposition technique.

  7. Effect of Monophasic Pulsed Current on Heel Pain and Functional Activities caused by Plantar Fasciitis

    PubMed Central

    Alotaibi, Abdullah K.; Petrofsky, Jerrold S.; Daher, Noha S.; Lohman, Everett; Laymon, Michael; Syed, Hasan M.

    2015-01-01

    Background Plantar fasciitis (PF) is a soft tissue disorder considered to be one of the most common causes of inferior heel pain. The aim of this study was to investigate the effect of monophasic pulsed current (MPC) and MPC coupled with plantar fascia-specific stretching exercises (SE) on the treatment of PF. Material/Methods Forty-four participants (22 women and 22 men, with a mean age of 49 years) diagnosed with PF were randomly assigned to receive MPC (n=22) or MPC coupled with plantar fascia-specific SE (n=22). Prior to and after 4 weeks of treatment, participants underwent baseline evaluation; heel pain was evaluated using a visual analogue scale (VAS), heel tenderness threshold was quantified using a handheld pressure algometer (PA), and functional activities level was assessed using the Activities of Daily Living subscale of the Foot and Ankle Ability Measure (ADL/FAAM). Results Heel pain scores showed a significant reduction in both groups compared to baseline VAS scores (P<0.001). Heel tenderness improved significantly in both groups compared with baseline PA scores (P<0.001). Functional activity level improved significantly in both groups compared with baseline (ADL/FAAM) scores (P<0.001). However, no significant differences existed between the 2 treatment groups in all post-intervention outcome measures. Conclusions This trial showed that MPC is useful in treating inferior heel symptoms caused by PF. PMID:25791231

  8. Effect of PIPS technique at different power settings on irrigating solution extrusion.

    PubMed

    Arslan, Hakan; Akcay, Merve; Ertas, Hüseyin; Capar, Ismail Davut; Saygili, Gökhan; Meşe, Merve

    2015-08-01

    The aim of this study was to determine the effect of photon-induced photoacoustic streaming (PIPS) technique at different power settings on extrusion of irrigating solution. Root canal preparation was performed up to a #30 file on 64 extracted single-rooted mandibular premolar teeth, which were then divided into four groups. Each group was irrigated with one of the following irrigation methods: (a) irrigation with conventional irrigation open-ended needles, (b) continuous ultrasonic irrigation, (c) 0.3 W PIPS, or (d) 0.9 W PIPS. Apical extrusion of irrigating solution was evaluated using a modified model. The net weight of the extruded irrigating solution was measured for each group, and the resulting data were analysed statistically using Kruskal-Wallis at a 95 % confidence level (P < 0.05). Although the 0.9 W PIPS group resulted in the largest quantity of irrigation solution, the ultrasonic group was the smallest. However, the difference between these groups was not statistically significant at the 95 % level of confidence (P > 0.05). PIPS at both 0.3 W and 0.9 W resulted similar solution extrusion to the conventional irrigation or ultrasonic irrigation. PMID:25037969

  9. Inverse solution technique of steady-state responses for local nonlinear structures

    NASA Astrophysics Data System (ADS)

    Wang, Xing; Guan, Xin; Zheng, Gangtie

    2016-03-01

    An inverse solution technique with the ability of obtaining complete steady-state primary harmonic responses of local nonlinear structures in the frequency domain is proposed in the present paper. In this method, the nonlinear dynamic equations of motion is first condensed from many to only one algebraic amplitude-frequency equation of relative motion. Then this equation is transformed into a polynomial form, and with its frequency as the unknown variable, the polynomial equation is solved by tracing all the solutions of frequency with the increase of amplitude. With this solution technique, some complicated dynamic behaviors such as sharp tuning, anomalous jumps, breaks in responses and detached resonance curves could be obtained. The proposed method is demonstrated and validated through a finite element beam under force excitations and a lumped parameter model with a local nonlinear element under base excitations. The phenomenon of detached resonance curves in the frequency response and its coupling effects with multiple linear modes in the latter example are observed.

  10. Gold nanoparticles prepared by electro-exploding wire technique in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Kumar, Lalit; Kapoor, Akanksha; Meghwal, Mayank; Annapoorni, S.

    2016-05-01

    This article presents an effective approach for the synthesis of Au nanoparticles via an environmentally benevolent electro-exploding wire (EEW) technique. In this process, Au nanoparticles evolve through the plasma generated from the parent Au metal. Compared to other typical chemical methods, electro-exploding wire technique is a simple and economical technique which normally operates in water or organic liquids under ambient conditions. Efficient size control was achieved using different aqueous medium like (1mM) NaCl, deionized water and aqueous solution of sodium hydroxide (NaOH, pH 9.5) using identical electro-exploding conditions. The gold nanoparticles exhibited the UV-vis absorption spectrum with a maximum absorption band at 530 nm, similar to that of gold nanoparticles chemically prepared in a solution. The mechanism of size variation of Au nanoparticles is also proposed. The results obtained help to develop methodologies for the control of EEW based nanoparticle growth and the functionalization of nanoparticle surfaces by specific interactions.

  11. Sleep and alertness during alternating monophasic and polyphasic rest-activity cycles.

    PubMed

    Porcú, S; Casagrande, M; Ferrara, M; Bellatreccia, A

    1998-07-01

    People involved in shift work often have to face altered patterns of sleep and wakefulness. This is particularly true for schedules involving night shifts and/or fragmentation of duty periods throughout the 24-hr day. In such conditions, it can be difficult to obtain satisfactory periods of sleep, and sleepiness on duty is a frequent and dangerous occurrence. The aim of this study was to evaluate sleep and wakefulness periods of subjects whose work schedule was characterized by an alternation of 2 hours of activity and 4 hours of rest (sleep allowed), repeated 4 times throughout the 24-hr day. This schedule was alternated with 24 hours off duty. Nine healthy male volunteers were monitored by means of ambulatory polysomnography while attending their 24-hr rest-activity schedule. Sleep periods were visually scored according to standard criteria. Wake periods were visually scored using both 30 s and 5 s epochs in order to reveal episodes of drowsiness and/or microsleep. Results showed that total sleep time was substantially reduced as compared to the usual 7-8 hour monophasic nocturnal sleep. Subjects did not sleep during the first rest period (11.00-15.00). Time in sleep linearly increased in the course of the 3 remaining rest periods. Normal sleep stage distribution was substantially spared only in the last rest period (3.00-7.00 a.m.). With regard to duty periods, only a few microsleeps were detected and their number did not significantly vary across the four 2-hr activity periods. In conclusion, this rest-activity schedule, despite the considerable sleep reduction, allowed maintaining good levels of vigilance as shown by the virtual absence of EEG microsleeps. Whether future research will prove that this regimen does not cause an impairment of performance, it should be a suitable strategy for the management of continuous operations. PMID:9845015

  12. Monophasic action potentials and Ca2+ transients in ischaemically preconditioned rabbit ventricular muscle

    PubMed Central

    Dekker, L.R.C.; van Bavel, E.; Opthof, T.; Coronel, R.; Janse, M.J.

    2003-01-01

    Background ATP-sensitive K+ (KATP) channels play an important role in the protective mechanism underlying ischaemic preconditioning. Ample evidence indicates, however, that action potential shortening is not a prerequisite for the cardioprotective effect of preconditioning. Methods Monophasic action potential duration (MAPD), tissue resistance, intracellular Ca2+ (Indo-1) and mechanical activity were simultaneously assessed in arterially perfused rabbit papillary muscles. We studied four experimental protocols preceding sustained ischaemia: 1. control perfusion (n=6), 2. ischaemic preconditioning (PC; n=4), 3. pretreatment with a KATP channel blocker, glibenclamide (15 μmol/1), prior to ischaemic preconditioning (PC+glib; n=3), 4. glibenclamide pretreatment only (Glib; n=2). Results In the PC group an increase in the diastolic Ca2+ level and a prolongation of the Ca2+ transient just prior to the induction of sustained ischaemia correlate to the postponement of the onset of irreversible ischaemic damage, as established by a rise in [Ca2+]i, electrical uncoupling and contracture. Glibenclamide antagonised these changes in the Ca2+ transient and the cardioprotection induced by preconditioning. MAPD was equal in all experimental groups. Conclusions Prolongation of the Ca2+ transient and increase of diastolic [Ca2+]i just prior to the induction of sustained ischaemia and not action potential shortening are involved in the cardioprotective effect of ischaemic preconditioning. Therefore, a glibenclamide-sensitive mechanism, other than the sarcolemmal KATP channels, is involved in the protective effect of ischaemic preconditioning. Changes in Ca2+ metabolism may play a crucial role in ischaemic preconditioning. ImagesFigure 1 PMID:25696182

  13. Various power quality challenges and solution techniques using FACTS technology for power system

    NASA Astrophysics Data System (ADS)

    Soni, J. Sandeep; Jangalwa, N. K.; Gupta, R.; Palwalia, D. K.

    2016-03-01

    This paper presents a comprehensive review on the various power quality problems and various solution techniques using FACTS in Power system. The term "Power Quality" is a broad concept and its meaning is taken different by different peoples. It is associated with electrical transmission, distribution and utilization systems those are having experience of any Voltage, current or frequency divergence from normal operation. Due to power quality problems industries have to invest large amount for mitigation of Voltage sags, distortions, harmonics and short term interruptions/disturbances etc. In paper authors tried to cover various possible sources and compensation methods of reactive power in power system.

  14. ‘Nano-impacts’: An Electrochemical Technique for Nanoparticle Sizing in Optically Opaque Solutions

    PubMed Central

    Toh, Her Shuang; Compton, Richard G

    2015-01-01

    Typical laser-dependent methods such as nanoparticle tracking analysis (NTA) and dynamic light scattering (DLS) are not able to detect nanoparticles in an optically opaque medium due to scattering or absorption of light. Here, the electrochemical technique of ‘nano-impacts’ was used to detect nanoparticles in solution in the presence of high levels of alumina particulates causing a milky white suspension. Using the ‘nano-impacts’ method, silver nanoparticles were successfully detected and sized in the model opaque medium. The results obtained compared well with those using transmission electron microscopy (TEM), an ex situ method for nanoparticle size determination. The ability to use the ‘nano-impacts’ method in media unmeasurable to competitor techniques confers a significant advantage on the electrochemical approach. PMID:26246985

  15. Inverse problem solution techniques as applied to indirect in situ estimation of fish target strength.

    PubMed

    Stepnowski, A; Moszyński, M

    2000-05-01

    In situ indirect methods of fish target strength (TS) estimation are analyzed in terms of the inverse techniques recently applied to the problem in question. The solution of this problem requires finding the unknown probability density function (pdf) of fish target strength from acoustic echoes, which can be estimated by solving the integral equation, relating pdf's of echo variable, target strength, and beam pattern of the echosounder transducer. In the first part of the paper the review of existing indirect in situ TS-estimation methods is presented. The second part introduces the novel TS-estimation methods, viz.: Expectation, Maximization, and Smoothing (EMS), Windowed Singular Value Decomposition (WSVD), Regularization and Wavelet Decomposition, which are compared using simulations as well as actual data from acoustic surveys. The survey data, acquired by the dual-beam digital echosounder, were thoroughly analyzed by numerical algorithms and the target strength and acoustical backscattering length pdf's estimates were calculated from fish echoes received in the narrow beam channel of the echosounder. Simultaneously, the estimates obtained directly from the dual-beam system were used as a reference for comparison of the estimates calculated by the newly introduced inverse techniques. The TS estimates analyzed in the paper are superior to those obtained from deconvolution or other conventional techniques, as the newly introduced methods partly avoid the problem of ill-conditioned equations and matrix inversion. PMID:10830379

  16. Note: A novel technique for analysis of aqueous solutions by laser-induced breakdown spectroscopy

    SciTech Connect

    Rusak, D. A.; Bell, Z. T.; Anthony, T. P.

    2015-11-15

    Surface-enhanced Raman spectroscopy (SERS) substrates typically consist of gold or silver nanoparticles deposited on a non-conductive substrate. In Raman spectroscopy, the nanoparticles produce an enhancement of the electromagnetic field which, in turn, leads to greater electronic excitation of molecules in the local environment. Here, we show that these same surfaces can be used to enhance the signal-to-noise ratio obtained in laser-induced breakdown spectroscopy of aqueous solutions. In this case, the SERS substrates not only lower breakdown thresholds and lead to more efficient plasma initiation but also provide an appropriately wettable surface for the deposition of the liquid. We refer to this technique as surface-enhanced laser-induced breakdown spectroscopy.

  17. Macromolecular conformation in solution. Study of carbonic anhydrase by the positron annihilation technique.

    PubMed Central

    Handel, E D; Graf, G; Glass, J C

    1980-01-01

    The structural features of carbonic anhydrase (carbonate hydro-lyase; EC 4.2.1.1) in aqueous solution were probed by the positron annihilation technique. The data obtained under varying conditions of temperature, pH, and enzyme concentration were interpreted in terms of the free volume model. The change of enzymic activity with temperature is accompanied by a change in free volume of the protein. Upon thermal denaturation an irreversible change in free volume of the molecule occurred. At low temperatures the protein-water interactions were investigated. These results are discussed in terms of current concepts of structure-function relationships in proteins. This study shows the sensitivity of the positron annihilation method toward the structure of proteins related to their overall conformation and to the nature of bound water. PMID:6789901

  18. Growth and characterization of urea-oxalic acid crystals by solution growth technique

    NASA Astrophysics Data System (ADS)

    Chithambaram, V.; Jerome Das, S.; Krishnan, Sivakumar; Basheer Ahamed, M.; Arivudai Nambi, R.

    2013-11-01

    Single crystals of urea-oxalic acid (UOA) have been grown from aqueous solution by slow evaporation technique. Single crystal X-ray diffraction analysis confirmed that the grown crystals belong to monoclinic system having space group P21/C. The presence of functional groups was confirmed by using Fourier transform infrared (FTIR) spectroscopy. Optical absorption studies show very low absorption in entire visible region and the UV cut-off is found to be around 240 nm. Thermal analysis studies were carried out using TG/DTA analysis and the grown crystal is thermally stable up to 180 °C. Dielectric constant studies confirm the ferroelectric property of the materials and very low dielectric loss reveals very high purity of the crystal.

  19. Matrix-free Brownian dynamics simulation technique for semidilute polymeric solutions

    NASA Astrophysics Data System (ADS)

    Saadat, Amir; Khomami, Bamin

    2015-09-01

    Evaluating the concentration dependence of static and dynamic properties of macromolecules in semidilute polymer solutions requires accurate calculation of long-range hydrodynamic interactions (HI) and short range excluded volume (EV) forces. In conventional Brownian dynamics simulations (BDS), computation of HI necessitates construction of a dense diffusion tensor commonly performed via Ewald summation. Krylov subspace techniques allow efficient decomposition of this tensor [computational cost scales as O (N2) , where N is the total number of beads in bead-spring representation of macromolecules in a simulation box] and computation of Brownian displacements in the box. In this paper, a matrix-free approach for calculation of HI is implemented which leads to O (N logN ) scaling of computational expense. The fidelity of the algorithm is demonstrated by evaluating the asymptotic value of center-of-mass diffusivity of polymer molecules at very low concentrations and their radius of gyration scaling as a function of number of beads for dilute and semidilute solutions (with concentrations up to 5 times the overlap concentration). In turn, a favorable comparison between our results and the blob theory is shown.

  20. The discussion of crucial techniques in the emergency solution of special equipment security systems

    NASA Astrophysics Data System (ADS)

    Li, Zhao; Liu, Renyi; Liu, Nan

    2007-06-01

    This paper analyzes the necessity and feasibility of the supervision of special equipment security. The emergency solution of special equipment security system aims to integrate the emergency response department, such as police security, fire control, first aid, and traffic police and so on, to conduct the disaster rescue jointly under the command of the government departments. China Special Equipment Inspection and Research Center launched a GIS based system that manages the special equipment security. It designs the database, software and hardware structure, and functional module of the emergency solution of special equipment security based on WebGIS and GPS techniques. This paper analyzes three key issues of this system is explosion model, security patrol vehicles and special vehicles GPS positioning and special equipment monitoring. This system uses the information sharing technology based on Web Service. Transplanting GIS to Internet, designs special equipment spatial data WebGIS web site. B/S architecture is used in the system, and the software SuperMap IS Java of SuperMap Company is used as the GIS server for the spatial data publishing. This system also contains a PDA platform that provide for fieldwork.

  1. Surface charge microscopy: novel technique for mapping charge-mosaic surfaces in electrolyte solutions.

    PubMed

    Yin, Xihui; Drelich, Jaroslaw

    2008-08-01

    The effective surface potential, called the zeta potential, is commonly determined from electrophoretic mobility measurements for particles moving in a solution in response to an electric field applied between two electrodes. The situation can be reversed, with the solution being forced to flow through a plug of packed particles, and the streaming potential of the particles can be calculated. A significant limitation of these electrokinetic measurements is that only an average value of the zeta potential/streaming potential is measured--regardless of whether the surface charge distribution is homogeneous or otherwise. However, in real-world situations, nearly all solids (and liquids) of technological significance exhibit surface heterogeneities. To detect heterogeneities in surface charge, analytical tools which provide accurate and spatially resolved information about the material surface potential--particularly at microscopic and submicroscopic resolutions--are needed. In this study, atomic force microscopy (AFM) was used to measure the surface interaction forces between a silicon nitride AFM cantilever and a multiphase volcanic rock. The experiments were conducted in electrolyte solutions with different ionic strengths and pH values. The colloidal force measurements were carried out stepwise across the boundary between adjacent phases. At each location, the force-distance curves were recorded. Surface charge densities were then calculated by fitting the experimental data with a DLVO theoretical model. Significant differences between the surface charge densities of the two phases and gradual transitions in the surface charge density at the interface were observed. It is demonstrated that this novel technique can be applied to examine one- and two-dimensional distributions of the surface potential. PMID:18620435

  2. School Counselors' Use of Solution-Focused Tenets and Techniques in School-Based Site Supervision

    ERIC Educational Resources Information Center

    Cigrand, Dawnette L.; Wood, Susannah M.; Duys, David

    2014-01-01

    The tenets and techniques of solution-focused (SF) theory have potential for application to school counseling site supervision; however, research on the use of these practices in site supervision is needed. This study examined the extent to which school counseling site supervisors integrated SF tenets and techniques into their supervisory…

  3. First evidence on phloem transport of nanoscale calcium oxide in groundnut using solution culture technique

    NASA Astrophysics Data System (ADS)

    Deepa, Manchala; Sudhakar, Palagiri; Nagamadhuri, Kandula Venkata; Balakrishna Reddy, Kota; Giridhara Krishna, Thimmavajjula; Prasad, Tollamadugu Naga Venkata Krishna Vara

    2015-06-01

    Nanoscale materials, whose size typically falls below 100 nm, exhibit novel chemical, physical and biological properties which are different from their bulk counterparts. In the present investigation, we demonstrated that nanoscale calcium oxide particles (n-CaO) could transport through phloem tissue of groundnut unlike the corresponding bulk materials. n-CaO particles are prepared using sol-gel method. The size of the as prepared n-CaO measured (69.9 nm) using transmission electron microscopic technique (TEM). Results of the hydroponics experiment using solution culture technique revealed that foliar application of n-CaO at different concentrations (10, 50, 100, 500, 1,000 ppm) on groundnut plants confirmed the entry of calcium into leaves and stems through phloem compared to bulk source of calcium sprayed (CaO and CaNO3). After spraying of n-CaO, calcium content in roots, shoots and leaves significantly increased. Based on visual scoring of calcium deficiency correction and calcium content in plant parts, we may establish the fact that nanoscale calcium oxide particles (size 69.9 nm) could move through phloem tissue in groundnut. This is the first report on phloem transport of nanoscale calcium oxide particles in plants and this result points to the use of nanoscale calcium oxide particles as calcium source to the plants through foliar application, agricultural crops in particular, as bulk calcium application through foliar nutrition is restricted due to its non-mobility in phloem.

  4. Technique for Calculating Solution Derivatives With Respect to Geometry Parameters in a CFD Code

    NASA Technical Reports Server (NTRS)

    Mathur, Sanjay

    2011-01-01

    A solution has been developed to the challenges of computation of derivatives with respect to geometry, which is not straightforward because these are not typically direct inputs to the computational fluid dynamics (CFD) solver. To overcome these issues, a procedure has been devised that can be used without having access to the mesh generator, while still being applicable to all types of meshes. The basic approach is inspired by the mesh motion algorithms used to deform the interior mesh nodes in a smooth manner when the surface nodes, for example, are in a fluid structure interaction problem. The general idea is to model the mesh edges and nodes as constituting a spring-mass system. Changes to boundary node locations are propagated to interior nodes by allowing them to assume their new equilibrium positions, for instance, one where the forces on each node are in balance. The main advantage of the technique is that it is independent of the volumetric mesh generator, and can be applied to structured, unstructured, single- and multi-block meshes. It essentially reduces the problem down to defining the surface mesh node derivatives with respect to the geometry parameters of interest. For analytical geometries, this is quite straightforward. In the more general case, one would need to be able to interrogate the underlying parametric CAD (computer aided design) model and to evaluate the derivatives either analytically, or by a finite difference technique. Because the technique is based on a partial differential equation (PDE), it is applicable not only to forward mode problems (where derivatives of all the output quantities are computed with respect to a single input), but it could also be extended to the adjoint problem, either by using an analytical adjoint of the PDE or a discrete analog.

  5. Prevalence and Characterization of Monophasic Salmonella Serovar 1,4,[5],12:i:- of Food Origin in China

    PubMed Central

    Yang, Xiaojuan; Wu, Qingping; Zhang, Jumei; Huang, Jiahui; Guo, Weipeng; Cai, Shuzhen

    2015-01-01

    Salmonella enterica subsp. enterica serovar 1,4,[5],12:i:- is a monophasic variant of Salmonella Typhimurium, which has recently been recognized as an emerging cause of infection worldwide. This bacterium has also ranked among the four most frequent serovars causing human salmonellosis in China. However, there are no reports on its contamination in Chinese food. Serotyping, polymerase chain reaction, antibiotic resistance, virulotyping, and multilocus sequence typing (MLST) assays were used to investigate the prevalence of this serological variant in food products in China, and to determine phenotypic and genotypic difference of monophasic isolates and Salmonella Typhimurium isolated over the same period. Salmonella 1,4,[5],12:i:- was prevalent in various food sources, including beef, pork, chicken, and pigeon. The study also confirmed the high prevalence (53.8%) of resistance to ampicillin, streptomycin, sulfonamides, and tetracycline in Salmonella 1,4,[5],12:i:-, which was higher than that in Salmonella Typhimurium. Moreover, Salmonella 1,4,[5],12:i:- isolates in our study were different from Salmonella Typhimurium isolates by the absence of three plasmid-borne genes (spvC, pefA, and rck) and the presence of gipA in all isolates. All Salmonella 1,4,[5],12:i:- isolates demonstrated MLST pattern ST34. Genomic deletions within the fljBA operon and surrounding genes were only found in Salmonella 1,4,[5],12:i:- isolates, with all isolates containing a deletion of fljB. However, hin and iroB were identified in all Salmonella 1,4,[5],12:i:- isolates. Three different deletion profiles were observed and two of them were different from the reported Salmonella 1,4,[5],12:i:- clones from Spain, America, and Italy, which provided some new evidence on the independent evolution of the multiple successful monophasic clones from Salmonella Typhimurium ancestors. This study is the first report of Salmonella 1,4,[5],12:i:- in food products from China. The data are more

  6. Prevalence and Characterization of Monophasic Salmonella Serovar 1,4,[5],12:i:- of Food Origin in China.

    PubMed

    Yang, Xiaojuan; Wu, Qingping; Zhang, Jumei; Huang, Jiahui; Guo, Weipeng; Cai, Shuzhen

    2015-01-01

    Salmonella enterica subsp. enterica serovar 1,4,[5],12:i:- is a monophasic variant of Salmonella Typhimurium, which has recently been recognized as an emerging cause of infection worldwide. This bacterium has also ranked among the four most frequent serovars causing human salmonellosis in China. However, there are no reports on its contamination in Chinese food. Serotyping, polymerase chain reaction, antibiotic resistance, virulotyping, and multilocus sequence typing (MLST) assays were used to investigate the prevalence of this serological variant in food products in China, and to determine phenotypic and genotypic difference of monophasic isolates and Salmonella Typhimurium isolated over the same period. Salmonella 1,4,[5],12:i:- was prevalent in various food sources, including beef, pork, chicken, and pigeon. The study also confirmed the high prevalence (53.8%) of resistance to ampicillin, streptomycin, sulfonamides, and tetracycline in Salmonella 1,4,[5],12:i:-, which was higher than that in Salmonella Typhimurium. Moreover, Salmonella 1,4,[5],12:i:- isolates in our study were different from Salmonella Typhimurium isolates by the absence of three plasmid-borne genes (spvC, pefA, and rck) and the presence of gipA in all isolates. All Salmonella 1,4,[5],12:i:- isolates demonstrated MLST pattern ST34. Genomic deletions within the fljBA operon and surrounding genes were only found in Salmonella 1,4,[5],12:i:- isolates, with all isolates containing a deletion of fljB. However, hin and iroB were identified in all Salmonella 1,4,[5],12:i:- isolates. Three different deletion profiles were observed and two of them were different from the reported Salmonella 1,4,[5],12:i:- clones from Spain, America, and Italy, which provided some new evidence on the independent evolution of the multiple successful monophasic clones from Salmonella Typhimurium ancestors. This study is the first report of Salmonella 1,4,[5],12:i:- in food products from China. The data are more

  7. Characteristics of Salmonella enterica Serovar 4,[5],12:i:- as a Monophasic Variant of Serovar Typhimurium

    PubMed Central

    Ido, Noriko; Lee, Ken-ichi; Iwabuchi, Kaori; Izumiya, Hidemasa; Uchida, Ikuo; Kusumoto, Masahiro; Iwata, Taketoshi; Ohnishi, Makoto; Akiba, Masato

    2014-01-01

    Salmonella enterica subspecies enterica serovar 4,[5],12:i:- (S. 4,[5]12:i:-) is believed to be a monophasic variant of S. enterica serovar Typhimurium (S. Typhimurium). This study was conducted to corroborate this hypothesis and to identify the molecular and phenotypic characteristics of the S. 4,[5]12:i:- isolates in Japan. A total of 51 S. 4,[5]12:i:- isolates derived from humans, cattle, swine, chickens, birds, meat (pork), and river water in 15 prefectures in Japan between 2000 and 2010 were analyzed. All the S. 4,[5],12:i:- isolates were identified as S. Typhimurium by two different polymerase chain reactions (PCR) for identification of S. Typhimurium. Of the 51 S. 4,[5],12:i:- isolates, 39 (76.5%) harbored a 94-kb virulence plasmid, which is known to be specific for S. Typhimurium. These data suggest that the S. 4,[5],12:i:- isolates are monophasic variants of S. Typhimurium. The flagellar phase variation is induced by three adjacent genes (fljA, fljB, and hin) in the chromosome. The results of PCR mapping of this region and comparative genomic hybridization analysis suggested that the deletion of the fljAB operon and its flanking region was the major genetic basis of the monophasic phenotype of S. 4,[5],12:i:-. The fljAB operon and hin gene were detectable in eight of the S. 4,[5],12:i:- isolates with common amino acid substitutions of A46T in FljA and R140L in Hin. The introduction of these mutations into S. Typhimurium isolates led to the loss of selectability of isolates expressing the phase 2 H antigen. These data suggested that a point mutation was the genetic basis, at least in part, of the S. 4,[5],12:i:- isolates. The results of phenotypic analysis suggested that the S. 4,[5],12:i:- isolates in Japan consist of multiple distinct clones. This is the first detailed characterization of the S. 4,[5],12:i:- isolates derived from various sources across Japan. PMID:25093666

  8. A Novel Solution-Technique Applied to a Novel WAAS Architecture

    NASA Technical Reports Server (NTRS)

    Bavuso, J.

    1998-01-01

    The Federal Aviation Administration has embarked on an historic task of modernizing and significantly improving the national air transportation system. One system that uses the Global Positioning System (GPS) to determine aircraft navigational information is called the Wide Area Augmentation System (WAAS). This paper describes a reliability assessment of one candidate system architecture for the WAAS. A unique aspect of this study regards the modeling and solution of a candidate system that allows a novel cold sparing scheme. The cold spare is a WAAS communications satellite that is fabricated and launched after a predetermined number of orbiting satellite failures have occurred and after some stochastic fabrication time transpires. Because these satellites are complex systems with redundant components, they exhibit an increasing failure rate with a Weibull time to failure distribution. Moreover, the cold spare satellite build-time is Weibull and upon launch is considered to be a good-as-new system with an increasing failure rate and a Weibull time to failure distribution as well. The reliability model for this system is non-Markovian because three distinct system clocks are required: the time to failure of the orbiting satellites, the build time for the cold spare, and the time to failure for the launched spare satellite. A powerful dynamic fault tree modeling notation and Monte Carlo simulation technique with importance sampling are shown to arrive at a reliability prediction for a 10 year mission.

  9. Development of iterative techniques for the solution of unsteady compressible viscous flows

    NASA Technical Reports Server (NTRS)

    Hixon, Duane; Sankar, L. N.

    1993-01-01

    During the past two decades, there has been significant progress in the field of numerical simulation of unsteady compressible viscous flows. At present, a variety of solution techniques exist such as the transonic small disturbance analyses (TSD), transonic full potential equation-based methods, unsteady Euler solvers, and unsteady Navier-Stokes solvers. These advances have been made possible by developments in three areas: (1) improved numerical algorithms; (2) automation of body-fitted grid generation schemes; and (3) advanced computer architectures with vector processing and massively parallel processing features. In this work, the GMRES scheme has been considered as a candidate for acceleration of a Newton iteration time marching scheme for unsteady 2-D and 3-D compressible viscous flow calculation; from preliminary calculations, this will provide up to a 65 percent reduction in the computer time requirements over the existing class of explicit and implicit time marching schemes. The proposed method has ben tested on structured grids, but is flexible enough for extension to unstructured grids. The described scheme has been tested only on the current generation of vector processor architecture of the Cray Y/MP class, but should be suitable for adaptation to massively parallel machines.

  10. Studies of implicit and explicit solution techniques in transient thermal analysis of structures

    NASA Technical Reports Server (NTRS)

    Adelman, H. M.; Haftka, R. T.; Robinson, J. C.

    1982-01-01

    Studies aimed at an increase in the efficiency of calculating transient temperature fields in complex aerospace vehicle structures are reported. The advantages and disadvantages of explicit and implicit algorithms are discussed and a promising set of implicit algorithms with variable time steps, known as GEARIB, is described. Test problems, used for evaluating and comparing various algorithms, are discussed and finite element models of the configurations are described. These problems include a coarse model of the Space Shuttle wing, an insulated frame tst article, a metallic panel for a thermal protection system, and detailed models of sections of the Space Shuttle wing. Results generally indicate a preference for implicit over explicit algorithms for transient structural heat transfer problems when the governing equations are stiff (typical of many practical problems such as insulated metal structures). The effects on algorithm performance of different models of an insulated cylinder are demonstrated. The stiffness of the problem is highly sensitive to modeling details and careful modeling can reduce the stiffness of the equations to the extent that explicit methods may become the best choice. Preliminary applications of a mixed implicit-explicit algorithm and operator splitting techniques for speeding up the solution of the algebraic equations are also described.

  11. Analytical techniques for characterization of cyclodextrin complexes in aqueous solution: a review.

    PubMed

    Mura, Paola

    2014-12-01

    Cyclodextrins are cyclic oligosaccharides endowed with a hydrophilic outer surface and a hydrophobic inner cavity, able to form inclusion complexes with a wide variety of guest molecules, positively affecting their physicochemical properties. In particular, in the pharmaceutical field, cyclodextrin complexation is mainly used to increase the aqueous solubility and dissolution rate of poorly soluble drugs, and to enhance their bioavailability and stability. Analytical characterization of host-guest interactions is of fundamental importance for fully exploiting the potential benefits of complexation, helping in selection of the most appropriate cyclodextrin. The assessment of the actual formation of a drug-cyclodextrin inclusion complex and its full characterization is not a simple task and often requires the use of different analytical methods, whose results have to be combined and examined together. The purpose of the present review is to give, as much as possible, a general overview of the main analytical tools which can be employed for the characterization of drug-cyclodextrin inclusion complexes in solution, with emphasis on their respective potential merits, disadvantages and limits. Further, the applicability of each examined technique is illustrated and discussed by specific examples from literature. PMID:24680374

  12. Projection techniques for iterative solution of A(bar x) equals (bar b) with successive right-hand sides

    NASA Technical Reports Server (NTRS)

    Fischer, Paul F.

    1993-01-01

    Two projection techniques for computing approximate solutions to linear systems of the form A(bar x)(sup n) = (bar b)(sup n), for a sequence n = 1, 2, ..., e.g., such as arises from time discretization of a partial differential equation, are presented. The inexpensive approximate solutions can be used as initial guesses for iterative solution of the system, resulting in significantly reduced computational expense. Examples of two- and three-dimensional incompressible Navier-Stokes calculations are presented in which x represents the pressure, and A is a discrete Poisson operator. In flows containing significant dynamic activity, these projection techniques lead to as much as a two-fold reduction in solution time.

  13. Effects of radical scavengers on aqueous solutions exposed to heavy-ion irradiation using the liquid microjet technique

    NASA Astrophysics Data System (ADS)

    Nomura, Shinji; Tsuchida, Hidetsugu; Furuya, Ryousuke; Miyahara, Kento; Majima, Takuya; Itoh, Akio

    2015-12-01

    The effects of the radical scavenger ascorbic acid on water radiolysis are studied by fast heavy-ion irradiation of aqueous solutions of ascorbic acid, using the liquid microjet technique under vacuum. To understand the reaction mechanisms of hydroxyl radicals in aqueous solutions, we directly measure secondary ions emitted from solutions with different ascorbic acid concentrations. The yield of hydronium secondary ions is strongly influenced by the reaction between ascorbic acid and hydroxyl radicals. From analysis using a simple model considering chemical equilibria, we determine that the upper concentration limit of ascorbic acid with a radical scavenger effect is approximately 70 μM.

  14. Multigrid techniques for nonlinear eigenvalue probems: Solutions of a nonlinear Schroedinger eigenvalue problem in 2D and 3D

    NASA Technical Reports Server (NTRS)

    Costiner, Sorin; Taasan, Shlomo

    1994-01-01

    This paper presents multigrid (MG) techniques for nonlinear eigenvalue problems (EP) and emphasizes an MG algorithm for a nonlinear Schrodinger EP. The algorithm overcomes the mentioned difficulties combining the following techniques: an MG projection coupled with backrotations for separation of solutions and treatment of difficulties related to clusters of close and equal eigenvalues; MG subspace continuation techniques for treatment of the nonlinearity; an MG simultaneous treatment of the eigenvectors at the same time with the nonlinearity and with the global constraints. The simultaneous MG techniques reduce the large number of self consistent iterations to only a few or one MG simultaneous iteration and keep the solutions in a right neighborhood where the algorithm converges fast.

  15. Outbreak of unusual Salmonella enterica serovar Typhimurium monophasic variant 1,4 [5],12:i:-, Italy, June 2013 to September 2014.

    PubMed

    Cito, Francesca; Baldinelli, Francesca; Calistri, Paolo; Di Giannatale, Elisabetta; Scavia, Gaia; Orsini, Massimiliano; Iannetti, Simona; Sacchini, Lorena; Mangone, Iolanda; Candeloro, Luca; Conte, Annamaria; Ippoliti, Carla; Morelli, Daniela; Migliorati, Giacomo; Barile, Nadia Beatrice; Marfoglia, Cristina; Salucci, Stefania; Cammà, Cesare; Marcacci, Maurilia; Ancora, Massimo; Dionisi, Anna Maria; Owczartek, Slawomir; Luzzi, Ida

    2016-04-14

    Monophasic variant of Salmonella enterica subspecies enterica serovar Typhimurium (monophasic S. Typhimurium), with antigenic structure 1,4,[5],12:i:-, appears to be of increasing importance in Europe. In Italy, monophasic S. Typhimurium represented the third most frequent Salmonella serovar isolated from human cases between 2004 and 2008. From June 2013 to October 2014, a total of 206 human cases of salmonellosis were identified in Abruzzo region (Central Italy). Obtained clinical isolates characterised showed S. Typhimurium 1,4,[5],12:i:- with sole resistance to nalidixic acid, which had never been observed in Italy in monophasic S. Typhimurium, neither in humans nor in animals or foods. Epidemiological, microbiological and environmental investigations were conducted to try to identify the outbreak source. Cases were interviewed using a standardised questionnaire and microbiological tests were performed on human as well as environmental samples, including samples from fruit and vegetables, pigs, and surface water. Investigation results did not identify the final vehicle of human infection, although a link between the human cases and the contamination of irrigation water channels was suggested. PMID:27105170

  16. Re-examination of the structural properties of solid solutions Sr {sub x}Ca{sub 1-x}CO{sub 3}

    SciTech Connect

    Lucas-Girot, Anita . E-mail: anita.lucas@univ-rennes1.fr; Hernandez, Olivier; Oudadesse, Hassane

    2007-06-05

    We have re-examined the evolution of orthorhombic cell parameters as a function of the substitution parameter x in solid solutions Sr {sub x}Ca{sub 1-x}CO{sub 3} in order to clarify contradictory results found in the literature. Calcium carbonate has been synthesized in the presence of Sr{sup 2+} ions (Sr/Ca molar ratio ranging from 10{sup -2} to 1), using experimental conditions that previously allowed us to obtain monophasic aragonite. The precipitates obtained have been analysed using powder X-ray diffractometry (XRD) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The powder XRD data confirm the occurrence of purely monophasic strontian-aragonites. Moreover, the cell parameters as well as the substitution parameter x have been refined for 0 < x < 0.5 against powder XRD data through Rietveld refinement. On the other hand, x was deduced from chemical analysis by ICP-AES. The agreement between both techniques is very satisfactory. The evolution of the cell parameters as a function of x is found to be linear within the studied range, this feature being confirmed for the overall domain (0 {<=} x {<=} 1) if one takes into account the cell parameters of aragonite CaCO{sub 3} and strontionite SrCO{sub 3}. This result, that is consistent with the existence of continuous solid solutions obeying the Vegard's law in the Sr {sub x}Ca{sub 1-x}CO{sub 3} system, contradicts previously published assertions.

  17. Novel technique for phosphorus recovery from aqueous solutions using amorphous calcium silicate hydrates (A-CSHs).

    PubMed

    Okano, Kenji; Uemoto, Masahide; Kagami, Jumpei; Miura, Keiichi; Aketo, Tsuyoshi; Toda, Masaya; Honda, Kohsuke; Ohtake, Hisao

    2013-05-01

    A novel technique for phosphorus (P) recovery from aqueous solutions was developed using amorphous calcium silicate hydrates (A-CSHs). A-CSHs, which have a high Ca/Si molar ratio of 2.0 or greater, could be synthesized using unlimitedly available, inexpensive materials such as siliceous shale and calcium hydroxide. A-CSHs showed high performance for P recovery from an anaerobic sludge digestion liquor (ASDL) and the synthetic model liquor (s-ASDL) containing 89 mg PO4-P/L. After 20 min mixing, 1.5 g/L A-CSHs could remove approximately 69 and 73% PO4-P from ASDL and s-ASDL, respectively. By contrast, autoclaved lightweight concrete particles, which contained crystalline calcium silicate hydrates as a principal component, removed only 10 and 6% PO4-P from ASDL and s-ASDL, respectively, under the same experimental conditions. When A-CSHs were washed with deionized water to remove free Ca(OH)2, P removability was significantly improved (up to 82%) despite the reduction in the amount of Ca(2+) released. Unlike in the case of Ca(OH)2, no significant carbonate inhibition was observed with P removal by A-CSHs. Moreover, P removed by A-CSHs showed better settleability, filterability, and dewaterability than P precipitated with conventional CaCl2 and Ca(OH)2. The present study demonstrated that A-CSHs have great potential as a novel, beneficial material for P recovery and recycling. PMID:23497975

  18. Application of symbolic/numeric matrix solution techniques to the NASTRAN program

    NASA Technical Reports Server (NTRS)

    Buturla, E. M.; Burroughs, S. H.

    1977-01-01

    The matrix solving algorithm of any finite element algorithm is extremely important since solution of the matrix equations requires a large amount of elapse time due to null calculations and excessive input/output operations. An alternate method of solving the matrix equations is presented. A symbolic processing step followed by numeric solution yields the solution very rapidly and is especially useful for nonlinear problems.

  19. Solution-Phase Synthesis of Dipeptides: A Capstone Project That Employs Key Techniques in an Organic Laboratory Course

    ERIC Educational Resources Information Center

    Marchetti, Louis; DeBoef, Brenton

    2015-01-01

    A contemporary approach to the synthesis and purification of several UV-active dipeptides has been developed for the second-year organic laboratory. This experiment exposes students to the important technique of solution-phase peptide synthesis and allows an instructor to highlight the parallel between what they are accomplishing in the laboratory…

  20. Measurement of resistance to solute transport across surfactant-laden interfaces using a Fluorescence Recovery After Photobleaching (FRAP) technique

    NASA Technical Reports Server (NTRS)

    Browne, Edward P.; Nivaggioli, Thierry; Hatton, T. Alan

    1994-01-01

    A noninvasive fluorescence recovery after photobleaching (FRAP) technique is under development to measure interfacial transport in two phase systems without disturbing the interface. The concentration profiles of a probe solute are measured in both sides of the interface by argon-ion laser, and the system relaxation is then monitored by a microscope-mounted CCD camera.

  1. Extending the Constant Coefficient Solution Technique to Variable Coefficient Ordinary Differential Equations

    ERIC Educational Resources Information Center

    Mohammed, Ahmed; Zeleke, Aklilu

    2015-01-01

    We introduce a class of second-order ordinary differential equations (ODEs) with variable coefficients whose closed-form solutions can be obtained by the same method used to solve ODEs with constant coefficients. General solutions for the homogeneous case are discussed.

  2. A novel numerical technique to obtain an accurate solution to the Thomas-Fermi equation

    NASA Astrophysics Data System (ADS)

    Parand, Kourosh; Yousefi, Hossein; Delkhosh, Mehdi; Ghaderi, Amin

    2016-07-01

    In this paper, a new algorithm based on the fractional order of rational Euler functions (FRE) is introduced to study the Thomas-Fermi (TF) model which is a nonlinear singular ordinary differential equation on a semi-infinite interval. This problem, using the quasilinearization method (QLM), converts to the sequence of linear ordinary differential equations to obtain the solution. For the first time, the rational Euler (RE) and the FRE have been made based on Euler polynomials. In addition, the equation will be solved on a semi-infinite domain without truncating it to a finite domain by taking FRE as basic functions for the collocation method. This method reduces the solution of this problem to the solution of a system of algebraic equations. We demonstrated that the new proposed algorithm is efficient for obtaining the value of y'(0) , y(x) and y'(x) . Comparison with some numerical and analytical solutions shows that the present solution is highly accurate.

  3. Patterning titania with the conventional and modified micromolding in capillaries technique from sol-gel and dispersion solutions

    NASA Astrophysics Data System (ADS)

    Ullah Khan, Sajid; ten Elshof, Johan E.

    2012-04-01

    We report TiO2 patterns obtained by a soft-lithographic technique called 'micromolding in capillaries' using sol-gel and dispersion solutions. A comparison between patterning with a sol-gel and dispersion solutions has been performed. The patterns obtained from sol-gel solutions showed good adhesion to the substrate and uniform shapes, but large shrinkage, whereas those obtained from dispersion solution had high solid content, but exhibited poor adhesion and non-uniform shapes. A fabrication method of a layer-by-layer structured pattern is also demonstrated. This type of pattern may find application in sensors, waveguides and other photonics elements. The occurrence of an undesirable residue layer, which hinders the fabrication of isolated patterns, is highlighted and a method of prevention is suggested.

  4. Behavior of Dental/Implant Alloys in Commercial Mouthwash Solution Studied by Electrochemical Techniques

    NASA Astrophysics Data System (ADS)

    Mareci, Daniel; Strugaru, Sorin Iacob; Iacoban, Sorin; Bolat, Georgiana; Munteanu, Corneliu

    2013-03-01

    This study investigates the electrochemical behavior of the various dental materials: Paliag (Ag-Pd based), Wiron 99 (Ni-Cr based), Cp-Ti (commercial pure titanium), and experimental Ti12Mo5Ta alloy in commercial mouthwash solution with 500 ppm F- (Oral B®) and compares it with the behavior of the same dental materials in artificial saliva. Linear potentiodynamic polarization (LPP) and electrochemical impedance spectroscopy (EIS) are the electrochemical procedures of investigation. The passivation of all dental samples in artificial saliva and mouthwash solution occurred spontaneously at open circuit potential. The corrosion current density of all tested dental materials in mouthwash solution were low (1-2 μA/cm2). The results suggest a non-predominant fluoride effect on the passive layer formed on all samples at open circuit potential. No passivation could be established with Paliag alloy when polarized in mouthwash solution. The EIS results confirm that all dental sample exhibit passivity in mouthwash solution at open circuit potential (polarization resistance was around 5 × 105 Ω cm2). For Paliag alloy after LPP in mouthwash solution the protectiveness passive layer was no more present. The corrosion resistances of four dental materials in mouthwash solution are in the following order: Ti12Mo5Ta > Cp-Ti > Wiron 99 > Paliag.

  5. Techniques for correcting approximate finite difference solutions. [applied to transonic flow

    NASA Technical Reports Server (NTRS)

    Nixon, D.

    1979-01-01

    A method of correcting finite-difference solutions for the effect of truncation error or the use of an approximate basic equation is presented. Applications to transonic flow problems are described and examples given.

  6. Comparison of In Situ Polymerization and Solution-Dispersion Techniques in the Preparation of Polyimide/Montmorillonite (MMT) Nanocomposites

    PubMed Central

    Ahmad, Mansor Bin; Gharayebi, Yadollah; Salit, Mohd. Sapuan; Hussein, Mohd. Zobir; Shameli, Kamyar

    2011-01-01

    In this paper, Polyimide/Montmorillonite Nanocomposites (PI/MMT NCs), based on aromatic diamine (4-Aminophenyl sulfone) (APS) and aromatic dianhydride (3,3′,4,4′-benzophenonetetracarboxylic dianhydride) (BTDA) were prepared using in situ polymerization and solution-dispersion techniques. The prepared PI/MMT NCs films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The XRD results showed that at the content of 1.0 wt % Organo Montmorillonite (OMMT) for two techniques and 3.0 wt % OMMT for the in situ polymerization technique, the OMMT was well-intercalated, exfoliated and dispersed into polyimide matrix. The OMMT agglomerated when its amount exceeded 10 wt % and 3.0 wt % for solution-dispersion and in situ polymerization techniques respectively. These results were confirmed by the TEM images of the prepared PI/MMT NCs. The TGA thermograms indicated that thermal stability of prepared PI/MMT NCs were increased with the increase of loading that, the effect is higher for the samples prepared by in situ polymerization technique. PMID:22016643

  7. On the solution of two-point linear differential eigenvalue problems. [numerical technique with application to Orr-Sommerfeld equation

    NASA Technical Reports Server (NTRS)

    Antar, B. N.

    1976-01-01

    A numerical technique is presented for locating the eigenvalues of two point linear differential eigenvalue problems. The technique is designed to search for complex eigenvalues belonging to complex operators. With this method, any domain of the complex eigenvalue plane could be scanned and the eigenvalues within it, if any, located. For an application of the method, the eigenvalues of the Orr-Sommerfeld equation of the plane Poiseuille flow are determined within a specified portion of the c-plane. The eigenvalues for alpha = 1 and R = 10,000 are tabulated and compared for accuracy with existing solutions.

  8. Probabilistic solution of random SI-type epidemiological models using the Random Variable Transformation technique

    NASA Astrophysics Data System (ADS)

    Casabán, M.-C.; Cortés, J.-C.; Romero, J.-V.; Roselló, M.-D.

    2015-07-01

    This paper presents a full probabilistic description of the solution of random SI-type epidemiological models which are based on nonlinear differential equations. This description consists of determining: the first probability density function of the solution in terms of the density functions of the diffusion coefficient and the initial condition, which are assumed to be independent random variables; the expectation and variance functions of the solution as well as confidence intervals and, finally, the distribution of time until a given proportion of susceptibles remains in the population. The obtained formulas are general since they are valid regardless the probability distributions assigned to the random inputs. We also present a pair of illustrative examples including in one of them the application of the theoretical results to model the diffusion of a technology using real data.

  9. The surface reactivity of a magnesium-aluminium alloy in acidic fluoride solutions studied by electrochemical techniques and XPS

    NASA Astrophysics Data System (ADS)

    Verdier, S.; van der Laak, N.; Delalande, S.; Metson, J.; Dalard, F.

    2004-08-01

    The behaviour of the 6% Al magnesium alloy AM60 in aqueous acid fluoride solutions was studied in situ by electrochemical techniques and the surface chemistry of the resulting film was examined by monochromatized XPS. The evolution of the corrosion potential and cyclic voltammograms showed that the aggressiveness of the solutions is mainly driven by their fluoride concentration, the pH having almost no detectable influence. The more concentrated and acidic fluoride solutions led to a higher degree of fluoride coverage of the surface. The surface film is composed of magnesium hydroxide and hydroxyfluoride Mg(OH) 2- xF x which approaches MgF 2 with increasing fluoride concentration in the film. The parameters governing the film evolution and their relation to surface reactions are discussed.

  10. The use of surface analytical techniques to measure the loadings of uranium and plutonium sorbed simultaneously from solution onto rocks

    SciTech Connect

    Berry, J.A.; Bishop, H.E.; Cowper, M.M.; Fozard, P.R.; McMillan, J.W.

    1995-12-31

    Small polished blocks of granite, diorite and dolerite were immersed in solutions containing uranium and plutonium at equal initial concentration.The samples were analyzed by the advanced surface analytical techniques of secondary ion mass spectrometry (SIMS) and nuclear microprobe analysis. The results show that both actinides sorb onto the same minerals in the three rocks. However, SIMS data show that significantly more uranium was sorbed than plutonium.

  11. An alternate solution for the treatment of ascending aortic aneurysms: the wrapping technique

    PubMed Central

    2010-01-01

    Background The aortic Dacron wrapping technique is a surgical technique used under certain circumstances in cases of ascending aorta dilatation. Herein, we are presenting our experience on the method performed on multimorbid patients who denied major aortic surgery. Methods We included in our series 7 patients (5 male-2 female) with mild to moderate ascending aortic dilatation, who were operated with the wrapping technique. One patient was submitted to biological aortic valve replacement during the same procedure. The number of conventionally operated patients during the same period (2 years) was 21. Results Mortality during the 18-months follow-up control was 0%. One patient had to be operated with biological aortic valve replacement 18 months after the initial wrapping operation, although the diameter of her ascending aorta remained stable. Conclusions The Dacron wrapping technique is a method that can alternatively be used in multimorbid patients with mild to moderate ascending aortic dilatation without dissecting elements and has generally good results. PMID:21047398

  12. Demonstration of a Solution Film Leak Test Technique and Equipment for the S00645 Canister Closure

    SciTech Connect

    Cannell, G.R.

    1999-10-07

    The purpose of this effort was to demonstrate that the SFT technique, when adapted to a DWPF canister nozzle, is capable of detecting leaks not meeting the Waste Acceptance Product Specifications (WAPS) acceptance criterion.

  13. A Comparison of Cocrystal Structure Solutions from Powder and Single Crystal Techniques

    SciTech Connect

    S Lapidus; P Stephens; K Arora; T Shattock; M Zaworotko

    2011-12-31

    We demonstrate the effectiveness and accuracy of high resolution powder diffraction for determination of cocrystal structures through a double-blind study. Structures of 10 cocrystals of varying complexity were determined independently using single crystal and powder techniques. The two methodologies give identical molecular packing and hydrogen bond topology, and an rms difference in covalent bond lengths of 0.035 {angstrom}. Powder techniques are clearly sufficient to establish a complete characterization of cocrystal geometry.

  14. Spectrophotometric technique quantitatively determines NaMBT inhibitor in ethylene glycol-water solutions

    NASA Technical Reports Server (NTRS)

    Garrard, G. G.

    1967-01-01

    Spectrophotometric method, using a ratio-recording ultraviolet-absorption spectrophotometer, permits analysis of NaMBT in ethylene glycol-water solutions with high accuracy. It reduces analysis time, requires smaller samples, and is able to detect extremely small concentrations of mercaptobenzothiazole.

  15. Comparison of three Stark problem solution techniques for the bounded case

    NASA Astrophysics Data System (ADS)

    Hatten, Noble; Russell, Ryan P.

    2015-01-01

    Three methods of obtaining solutions to the Stark problem—one developed by Lantoine and Russell using Jacobi elliptic and related functions, one developed by Biscani and Izzo using Weierstrass elliptic and related functions, and one developed by Pellegrini, Russell, and Vittaldev using and Taylor series extended to the Stark problem—are compared qualitatively and quantitatively for the bounded motion case. For consistency with existing available code for the series solution, Fortran routines of the Lantoine method and Biscani method are newly implemented and made available. For these implementations, the Lantoine formulation is found to be more efficient than the Biscani formulation in the propagation of a single trajectory segment. However, for applications for which acceptable accuracy may be achieved by orders up to 16, the Pellegrini series solution is shown to be more efficient than either analytical method. The three methods are also compared in the propagation of sequentially connected trajectory segments in a low-thrust orbital transfer maneuver. Separate tests are conducted for discretizations between 8 and 96 segments per orbit. For the series solution, the interaction between order and step size leads to computation times that are nearly invariable to discretization for a given truncation error tolerance over the tested range of discretizations. This finding makes the series solution particularly attractive for mission design applications where problems may require both coarse and fine discretizations. Example applications include the modeling of low-thrust propulsion and time-varying perturbations—problems for which the efficient propagation of relatively short Stark segments is paramount because the disturbing acceleration generally varies continuously.

  16. Mineralisation of amethyst-bearing geodes in Ametista do Sul (Brazil) from low-temperature sedimentary brines: evidence from monophase liquid inclusions and stable isotopes

    NASA Astrophysics Data System (ADS)

    Gilg, H. Albert; Krüger, Yves; Taubald, Heinrich; van den Kerkhof, Alfons M.; Frenz, Martin; Morteani, Giulio

    2014-10-01

    Fluid inclusion studies in combination with hydrogen, oxygen and sulphur isotope data provide novel insights into the genesis of giant amethyst-bearing geodes in Early Cretaceous Paraná continental flood basalts at Amestita do Sul, Brazil. Monophase liquid inclusions in colourless quartz, amethyst, calcite, barite and gypsum were analysed by microthermometry after stimulating bubble nucleation using single femtosecond laser pulses. The salinity of the fluid inclusions was determined from ice-melting temperatures and a combination of prograde and retrograde homogenisation temperatures via the density maximum of the aqueous solutions. Four mineralisation stages are distinguished. In stage I, celadonite, chalcedony and pyrite formed under reducing conditions in a thermally stable environment. Low δ34SV-CDT values of pyrite (-25 to -32 ‰) suggest biogenic sulphate reduction by organotrophic bacteria. During the subsequent stages II (amethyst, goethite and anhydrite), III (early subhedral calcite) and IV (barite, late subhedral calcite and gypsum), the oxidation state of the fluid changed towards more oxidising conditions and microbial sulphate reduction ceased. Three distinct modes of fluid salinities around 5.3, 3.4 and 0.3 wt% NaCl-equivalent characterise the mineralisation stages II, III and IV, respectively. The salinity of the stage I fluid is unknown due to lack of fluid inclusions. Variation in homogenisation temperatures and in δ18O values of amethyst show evidence of repeated pulses of ascending hydrothermal fluids of up to 80-90 °C infiltrating a basaltic host rock of less than 45 °C. Colourless quartz and amethyst formed at temperatures between 40 and 80 °C, while the different calcite generations and late gypsum precipitated at temperatures below 45 °C. Calculated oxygen isotope composition of the amethyst-precipitating fluid in combination with δD values of amethyst-hosted fluid inclusions (-59 to -51 ‰) show a significant 18O-shift from the

  17. Activation of ganglion cells in wild-type and rd1 mouse retinas with monophasic and biphasic current pulses

    NASA Astrophysics Data System (ADS)

    Jensen, Ralph J.; Rizzo, Joseph F. III

    2009-06-01

    We and other research groups are designing an electronic retinal prosthesis to provide vision for patients who are blind due to photoreceptor degeneration. In this study, we examined the effect of stimulus waveform on the amount of current needed to activate retinal ganglion cells (RGCs) when the retinal neural network is stimulated. Isolated retinas of wild-type and rd1 mice were stimulated with cathodal and anodal monophasic current pulses of 1 ms duration and symmetric biphasic current pulses (1 ms per phase) delivered through an electrode that was located subretinally. For both wild-type and rd1 mouse retinas, cathodal current pulses were least effective in activating most RGCs. The median threshold current for a cathodal current pulse was 2.0-4.4 fold higher than the median threshold current for either an anodal or a biphasic current pulse. In wild-type mouse retinas, the median threshold current for activating RGCs with anodal current pulses was 23% lower than that with biphasic current pulses. In rd1 mouse retinas, the median threshold currents for anodal and biphasic current pulses were about the same. However, the variance in thresholds of rd1 RGCs for biphasic pulse stimulation was much smaller than for anodal pulse stimulation. Thus, a symmetric biphasic current pulse may be the best stimulus for activating the greatest number of RGCs in retinas devoid of photoreceptors.

  18. A prospective study of a monophasic oral contraceptive containing 30 mcg ethinyl oestradiol and 150 mcg desogestrel (Marvelon).

    PubMed

    Ismail, M T

    1994-06-01

    Marvelon, a monophasic oral contraceptive (OC) containing 30 mcg of ethinyl estradiol and 150 mcg of desogestrel, has been available to Malaysian women through the national family planning program since 1982. To assess the safety, effectiveness, and side effects associated with this OC, 247 women who requested the pill were enrolled in a multicenter prospective study that included follow-up after the first, third, and sixth cycles of use. 81% of participants had never used any form of contraception before Marvelon. 194 women (79%) completed the 6-month study. There were no pregnancies recorded. Although women reported a slightly increased incidence of nausea, breast tenderness, and headache in the first treatment cycle, these side effects had abated by the end of the third cycle. After six cycles, mean body weight had decreased by an average of 0.4 kg. Both systolic and diastolic blood pressure were unaffected. An unexpected finding was a decrease in the severity of acne with continuous use of Marvelon. Although both spotting and breakthrough bleeding increased slightly in the first two cycles, irregular bleeding returned to pretreatment levels by the third cycle. The length of the withdrawal bleed in the pill-free week was reduced. The incidence of irregular bleeding and other side effects was substantially lower in this sample of Malaysian women than in Asian and Caucasian Marvelon users surveyed in other studies. PMID:12320338

  19. Extensive genetic variability linked to IS26 insertions in the fljB promoter region of atypical monophasic variants of Salmonella enterica serovar Typhimurium.

    PubMed

    Boland, Cécile; Bertrand, Sophie; Mattheus, Wesley; Dierick, Katelijne; Jasson, Vicky; Rosseel, Toon; Van Borm, Steven; Mahillon, Jacques; Wattiau, Pierre

    2015-05-01

    Fifty-nine monophasic Salmonella enterica serovar Typhimurium isolates, collected in Belgium during the period from 2008 to 2011, have been serotyped as 4,[5]:i:- and shown to harbor an fljB coding sequence. The genetic differences between these strains and phenotypically biphasic Salmonella Typhimurium were analyzed through PCR and DNA sequencing. Genetic alterations in the fljB promoter region affecting expression of the phase 2 flagellin were observed in 53 isolates. Other genetic events in the invertible region carrying the fljB promoter were observed in 2 isolates. For the remaining 4 isolates, no molecular differences with a reference biphasic Salmonella Typhimurium strain could be observed. Next-generation sequencing of one representative isolate affected in the fljB promoter region revealed a 26-kb IS26 composite transposon insertion along with a local genomic rearrangement. Several other IS26 element-mediated alterations of this genomic region were observed. This group of monophasic Salmonella Typhimurium isolates was genetically heterogeneous, as revealed by multilocus variable-number tandem-repeat analysis (MLVA), PCR, and sequencing. Pigs and pork represented a major source of such monophasic isolates in Belgium, as reported in other countries. Three out of 5 isolates of human origin presented genetic profiles identical to those of food isolates, demonstrating the pathogenic potential of the newly characterized variants and potential dissemination along the food chain. This study highlighted the key role played by IS26 insertions in the loss of phase 2 flagellin expression and the subsequent generation of multiple monophasic variant lineages from biphasic Salmonella Typhimurium ancestors. PMID:25724958

  20. Some path-following techniques for solution of nonlinear equations and comparison with parametric differentiation

    NASA Technical Reports Server (NTRS)

    Barger, R. L.; Walters, R. W.

    1986-01-01

    Some path-following techniques are described and compared with other methods. Use of multipurpose techniques that can be used at more than one stage of the path-following computation results in a system that is relatively simple to understand, program, and use. Comparison of path-following methods with the method of parametric differentiation reveals definite advantages for the path-following methods. The fact that parametric differentiation has found a broader range of applications indicates that path-following methods have been underutilized.

  1. Monitoring solute fluxes: Integrating electrical resistivity with multi-compartment sampler techniques

    NASA Astrophysics Data System (ADS)

    Bloem, Esther; Fernandez, Perrine; French, Helen K.

    2016-04-01

    The impact of agriculture, industry, airport activities on soil and water quality is strongly influenced by soil heterogeneity. To improve risk assessment, monitoring, and treatment strategies, we require a better understanding of the effect of soil heterogeneity on contaminant movement and better methods for monitoring heterogeneous contaminated transport. Sufficient characterization of spatial and temporal distribution of contaminant transport requires measurements of water and solute fluxes at multiple locations with a high temporal resolution. During this presentation, we will show a newly developed instrument, which combines multi-compartment sampling with electrical resistivity measurements, to observe spatial and temporal fluxes of contaminants. Solute monitoring is often limited to observations of resident concentrations, while flux concentrations govern the movement of solutes in soils. Bloem et al. (2010) developed a multi-compartment sampler (MCS) which is capable of measuring fluxes at a high spatial resolution under natural conditions. The sampler is divided into 100 separate compartments of 31 by 31 mm. Flux data can be recorded at a high time resolution (every 5 minutes). Tracer leaching can be monitored by frequently sampling the collected leachate while leaving the sampler buried in situ. To optimize the monitoring of tracer leaching and measure real solute fluxes the multi-compartment sampler has been extended with 121 electrodes. The electrodes are mounted at each corner of each compartment to measure the electrical conductivity above each compartment while water percolates through the compartments. By using different electrode couples, the setup can also be used to image above the multi-compartment sampler. The instrument can be used for detailed studies both in the laboratory and in the field. For laboratory experiments a transparent column is used which fits perfect on top of the MCS. We present a selection of the integrated electrical

  2. Adsorption kinetics of surfactant mixtures from micellar solutions as studied by maximum bubble pressure technique.

    PubMed

    Frese, Ch; Ruppert, S; Sugár, M; Schmidt-Lewerkühne, H; Wittern, K P; Fainerman, V B; Eggers, R; Miller, R

    2003-11-15

    The adsorption kinetics of micellar solutions of anionic/cationic SDS/DATB mixtures with mixing ratios of 10/1 and 10/2, respectively, are studied experimentally by means of the maximum bubble pressure method. For long adsorption times the adsorption of the highly surface-active anionic/cationic complex leads to a decrease of dynamic surface tension in comparison to the single SDS system. However, the situation is the reverse for short adsorption times where the dynamic surface tension is increased by addition of the cationic surfactant, although the overall concentration is increased. This unexpected behavior is explained by partial solubilization of free SDS molecules into micelles formed by SDS/DTAB complexes. With increasing overall concentration, when eventually the CMC of SDS is reached, the anionic/cationic complex itself is solubilized by SDS micelles. Finally, no complex micelles, which for their part can solubilize an excess of SDS molecules, are present. Hence, the dynamic properties of the solution are no longer influenced by the depletion of SDS molecules and the mixture tends to behave like a pure SDS solution. PMID:14583225

  3. Depolymerization of chitosan-metal complexes via a solution plasma technique.

    PubMed

    Pornsunthorntawee, Orathai; Katepetch, Chaiyapruk; Vanichvattanadecha, Chutima; Saito, Nagahiro; Rujiravanit, Ratana

    2014-02-15

    Chitosan-metal complexes were depolymerized under acidic conditions using a solution plasma system. Four different types of metal ions, including Ag(+), Zn(2+), Cu(2+), and Fe(3+) ions, were added to the chitosan solution at a metal-to-chitosan molar ratio of 1:8. The depolymerization rate was affected by the types of metal ions that form complexes with chitosan. The complexation of chitosan with Cu(2+) or Fe(3+) ions strongly promoted the depolymerization rate of chitosan using a solution plasma treatment. However, chitosan-Ag(+) and chitosan-Zn(2+) complexes exhibited no change in the depolymerization rate compared to chitosan. After plasma treatment of the chitosan-metal complexes, the depolymerized chitosan products were separated into water-insoluble and water-soluble fractions. The water-soluble fraction containing low-molecular-weight chitosan was obtained in a yield of less than 57% for the depolymerization of chitosan-Fe(3+) complex with the plasma treatment time of 180 min. PMID:24507312

  4. Fitting Flux Ropes to a Global MHD Solution: A Comparison of Techniques

    NASA Technical Reports Server (NTRS)

    Riley, Pete; Linker, J. A.; Lionello, R.; Mikic, Z.; Odstrcil, D.; Hidalgo, M. A.; Cid, C.; Hu, Q.; Lepping, R. P.; Lynch, B. J.; Rees, A.

    2004-01-01

    Flux rope fitting (FRF) techniques are an invaluable tool for extracting information about the properties of a sub-class of coronal mass ejections (CMEs) in the solar wind. However, it has proven difficult to assess their accuracy since the underlying global structure of the CME cannot be independently determined from the data. In contrast, large-scale MHD simulations of CME evolution can provide both a global view as well as localized time series at specific points in space. In this study we apply five different fitting techniques to two hypothetical time series derived from MHD simulation results. Independent teams performed the analysis of the events in "blind tests", for which no information, other than time series, was provided. From the results, we infer the following: 1) Accuracy decreases markedly with increasingly glancing encounters; 2) Correct identification of the boundaries of the flux rope can be a significant limiter; 3) Results from techniques that infer global morphology must be viewed with caution. In spite of these limitations, FRF techniques remain a useful tool for describing in situ observations of flux rope CMEs.

  5. Fitting Flux Ropes to a Global MHD Solution: A Comparison of Techniques. Appendix 1

    NASA Technical Reports Server (NTRS)

    Riley, Pete; Linker, J. A.; Lionello, R.; Mikic, Z.; Odstrcil, D.; Hidalgo, M. A.; Cid, C.; Hu, Q.; Lepping, R. P.; Lynch, B. J.

    2004-01-01

    Flux rope fitting (FRF) techniques are an invaluable tool for extracting information about the properties of a subclass of CMEs in the solar wind. However, it has proven difficult to assess their accuracy since the underlying global structure of the CME cannot be independently determined from the data. In contrast, large-scale MHD simulations of CME evolution can provide both a global view as well as localized time series at specific points in space. In this study we apply 5 different fitting techniques to 2 hypothetical time series derived from MHD simulation results. Independent teams performed the analysis of the events in "blind tests", for which no information, other than the time series, was provided. F rom the results, we infer the following: (1) Accuracy decreases markedly with increasingly glancing encounters; (2) Correct identification of the boundaries of the flux rope can be a significant limiter; and (3) Results from techniques that infer global morphology must be viewed with caution. In spite of these limitations, FRF techniques remain a useful tool for describing in situ observations of flux rope CMEs.

  6. Comparison of soil solution sampling techniques to assess metal fluxes from contaminated soil to groundwater.

    PubMed

    Coutelot, F; Sappin-Didier, V; Keller, C; Atteia, O

    2014-12-01

    The unsaturated zone plays a major role in elemental fluxes in terrestrial ecosystems. A representative chemical analysis of soil pore water is required for the interpretation of soil chemical phenomena and particularly to assess Trace Elements (TEs) mobility. This requires an optimal sampling system to avoid modification of the extracted soil water chemistry and allow for an accurate estimation of solute fluxes. In this paper, the chemical composition of soil solutions sampled by Rhizon® samplers connected to a standard syringe was compared to two other types of suction probes (Rhizon® + vacuum tube and Rhizon® + diverted flow system). We investigated the effects of different vacuum application procedures on concentrations of spiked elements (Cr, As, Zn) mixed as powder into the first 20 cm of 100-cm columns and non-spiked elements (Ca, Na, Mg) concentrations in two types of columns (SiO2 sand and a mixture of kaolinite + SiO2 sand substrates). Rhizon® was installed at different depths. The metals concentrations showed that (i) in sand, peak concentrations cannot be correctly sampled, thus the flux cannot be estimated, and the errors can easily reach a factor 2; (ii) in sand + clay columns, peak concentrations were larger, indicating that they could be sampled but, due to sorption on clay, it was not possible to compare fluxes at different depths. The different samplers tested were not able to reflect the elemental flux to groundwater and, although the Rhizon® + syringe device was more accurate, the best solution remains to be the use of a lysimeter, whose bottom is kept continuously at a suction close to the one existing in the soil. PMID:25277861

  7. A high-resolution numerical technique for inviscid gas-dynamic problems with weak solutions

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Warming, R. F.; Harten, A.

    1982-01-01

    The shock resolution of Harten's (1982) second-order explicit method for one-dimensional hyperbolic conservation laws is investigated for a two-dimensional gas-dynamic problem. The possible extension to a high resolution implicit method for both one- and two-dimensional problems is also investigated. Applications of Harten's method to the quasi-one-dimensional nozzle problem with two nozzle shapes (divergent and convergent-divergent) and the two-dimensional shock-reflection problem resulted in high shock resolution steady-state numerical solutions.

  8. On substructuring algorithms and solution techniques for the numerical approximation of partial differential equations

    NASA Technical Reports Server (NTRS)

    Gunzburger, M. D.; Nicolaides, R. A.

    1986-01-01

    Substructuring methods are in common use in mechanics problems where typically the associated linear systems of algebraic equations are positive definite. Here these methods are extended to problems which lead to nonpositive definite, nonsymmetric matrices. The extension is based on an algorithm which carries out the block Gauss elimination procedure without the need for interchanges even when a pivot matrix is singular. Examples are provided wherein the method is used in connection with finite element solutions of the stationary Stokes equations and the Helmholtz equation, and dual methods for second-order elliptic equations.

  9. Viscoelastic properties of healthy human artery measured in saline solution by AFM based indentation technique

    SciTech Connect

    Lundkvist, A.; Lilleodden, E.; Sickhaus, W.; Kinney, J.; Pruitt, L.; Balooch, M.

    1998-02-09

    Using an Atomic Force Microscope with an attachment for indentation, we have measured local, in vitro mechanical properties of healthy femoral artery tissue held in saline solution. The elastic modulus (34. 3 kPa) and viscoelastic response ({tau}sub{epsilon} {equals} 16.9 s and {tau}sub{sigma} {equals} 29.3 s) of the unstretched,intimal vessel wall have been determined using Sneddon theory and a three element model(standard linear solid) for viscoelastic materials. The procedures necessary to employ the indenting attachment to detect elastic moduli in the kPa range in liquid are described.

  10. Effective gene prediction by high resolution frequency estimator based on least-norm solution technique.

    PubMed

    Roy, Manidipa; Barman, Soma

    2014-01-01

    Linear algebraic concept of subspace plays a significant role in the recent techniques of spectrum estimation. In this article, the authors have utilized the noise subspace concept for finding hidden periodicities in DNA sequence. With the vast growth of genomic sequences, the demand to identify accurately the protein-coding regions in DNA is increasingly rising. Several techniques of DNA feature extraction which involves various cross fields have come up in the recent past, among which application of digital signal processing tools is of prime importance. It is known that coding segments have a 3-base periodicity, while non-coding regions do not have this unique feature. One of the most important spectrum analysis techniques based on the concept of subspace is the least-norm method. The least-norm estimator developed in this paper shows sharp period-3 peaks in coding regions completely eliminating background noise. Comparison of proposed method with existing sliding discrete Fourier transform (SDFT) method popularly known as modified periodogram method has been drawn on several genes from various organisms and the results show that the proposed method has better as well as an effective approach towards gene prediction. Resolution, quality factor, sensitivity, specificity, miss rate, and wrong rate are used to establish superiority of least-norm gene prediction method over existing method. PMID:24386895

  11. Effective gene prediction by high resolution frequency estimator based on least-norm solution technique

    PubMed Central

    2014-01-01

    Linear algebraic concept of subspace plays a significant role in the recent techniques of spectrum estimation. In this article, the authors have utilized the noise subspace concept for finding hidden periodicities in DNA sequence. With the vast growth of genomic sequences, the demand to identify accurately the protein-coding regions in DNA is increasingly rising. Several techniques of DNA feature extraction which involves various cross fields have come up in the recent past, among which application of digital signal processing tools is of prime importance. It is known that coding segments have a 3-base periodicity, while non-coding regions do not have this unique feature. One of the most important spectrum analysis techniques based on the concept of subspace is the least-norm method. The least-norm estimator developed in this paper shows sharp period-3 peaks in coding regions completely eliminating background noise. Comparison of proposed method with existing sliding discrete Fourier transform (SDFT) method popularly known as modified periodogram method has been drawn on several genes from various organisms and the results show that the proposed method has better as well as an effective approach towards gene prediction. Resolution, quality factor, sensitivity, specificity, miss rate, and wrong rate are used to establish superiority of least-norm gene prediction method over existing method. PMID:24386895

  12. Use of the Relaxometry Technique for Quantification of Paramagnetic Ions in Aqueous Solutions and a Comparison with Other Analytical Methods.

    PubMed

    Gomes, Bruna Ferreira; Burato, Juliana Soares da Silva; Silva Lobo, Carlos Manuel; Colnago, Luiz Alberto

    2016-01-01

    We have demonstrated that the relaxometry technique is very efficient to quantify paramagnetic ions during in situ electrolysis measurements. Therefore, the goal of this work was to validate the relaxometry technique in the determination of the concentration of the ions contained in electrolytic solutions, Cu(2+), Ni(2+), Cr(3+), and Mn(2+), and compare it with other analytical methods. Two different NMR spectrometers were used: a commercial spectrometer with a homogeneous magnetic field and a home-built unilateral sensor with an inhomogeneous magnetic field. Without pretreatment, manganese ions do not have absorption bands in the UV-Visible region, but it is possible to quantify them using relaxometry (the limit of quantification is close to 10(-5) mol L(-1)). Therefore, since the technique does not require chemical indicators and is a cheap and robust method, it can be used as a replacement for some conventional quantification techniques. The relaxometry technique could be applied to evaluate the corrosion of metallic surfaces. PMID:27293437

  13. Use of the Relaxometry Technique for Quantification of Paramagnetic Ions in Aqueous Solutions and a Comparison with Other Analytical Methods

    PubMed Central

    Burato, Juliana Soares da Silva; Silva Lobo, Carlos Manuel; Colnago, Luiz Alberto

    2016-01-01

    We have demonstrated that the relaxometry technique is very efficient to quantify paramagnetic ions during in situ electrolysis measurements. Therefore, the goal of this work was to validate the relaxometry technique in the determination of the concentration of the ions contained in electrolytic solutions, Cu2+, Ni2+, Cr3+, and Mn2+, and compare it with other analytical methods. Two different NMR spectrometers were used: a commercial spectrometer with a homogeneous magnetic field and a home-built unilateral sensor with an inhomogeneous magnetic field. Without pretreatment, manganese ions do not have absorption bands in the UV-Visible region, but it is possible to quantify them using relaxometry (the limit of quantification is close to 10−5 mol L−1). Therefore, since the technique does not require chemical indicators and is a cheap and robust method, it can be used as a replacement for some conventional quantification techniques. The relaxometry technique could be applied to evaluate the corrosion of metallic surfaces. PMID:27293437

  14. Surface Morphology and Microstructural Characterization of KCl Crystals Grown in Halite-Sylvite Brine Solutions by Electron Backscattered Diffraction Techniques

    NASA Astrophysics Data System (ADS)

    Podder, Jiban; Basu, Ritwik; Evitts, Richard William; Besant, Robert William

    2015-11-01

    In this paper, a study on the ternary NaCl-KCl-H2O system was carried out by an extractive metallurgy technique from mixed brine solutions of different compositions at room temperature (23°C). The surface morphology and microstructure were examined using a scanning electron microscope (SEM), electron backscattered diffraction (EBSD) and an energy dispersive X-ray (EDX) spectroscopy. The presence of Na{ }+ was found to reduce the stability of the solutions and increase the crystallization induction period, interfacial energy, energy of formation of the nucleus and greatly reduce the nucleation rate of KCl crystal. The surface morphology of KCl crystals is significantly changed due to presence of 5 to 10% (w/w) of NaCl as impurities in the binary solutions and shows the formation of co-crystals of different crystallographic orientation of NaCl on the KCl surface. In addition X-ray diffraction studies performed on KCl crystals grown in halite-sylvite binary solutions reveals that these crystals are cubic in nature and its lattice constant is 6.2952 Å when the NaCl concentration is small.

  15. Navier-Stokes solution on the CYBER-203 by a pseudospectral technique

    NASA Astrophysics Data System (ADS)

    Lambiotte, J. J.; Hussaini, M. Y.; Bokhari, S.; Orszag, S. A.

    A three-level, time-split, mixed spectral/finite difference method for the numerical solution of the three-dimensional, compressible Navier-Stokes equations has been developed and implemented on the Control Data Corporation (CDC) CYBER-203. This method uses a spectral representation for the flow variables in the streamwise and spanwise coordinates, and central differences in the normal direction. The five dependent variables are interleaved one horizontal plane at a time and the array of their values at the grid points of each horizontal plane is a typical vector in the computation. The code is organized so as to require, per time step, a single forward-backward pass through the entire data base. The one-and two-dimensional Fast Fourier Transforms are performed using software especially developed for the CYBER-203.

  16. Navier-Stokes solution on the CYBER-203 by a pseudospectral technique

    NASA Technical Reports Server (NTRS)

    Lambiotte, J. J.; Hussaini, M. Y.; Bokhari, S.; Orszag, S. A.

    1983-01-01

    A three-level, time-split, mixed spectral/finite difference method for the numerical solution of the three-dimensional, compressible Navier-Stokes equations has been developed and implemented on the Control Data Corporation (CDC) CYBER-203. This method uses a spectral representation for the flow variables in the streamwise and spanwise coordinates, and central differences in the normal direction. The five dependent variables are interleaved one horizontal plane at a time and the array of their values at the grid points of each horizontal plane is a typical vector in the computation. The code is organized so as to require, per time step, a single forward-backward pass through the entire data base. The one-and two-dimensional Fast Fourier Transforms are performed using software especially developed for the CYBER-203.

  17. Novel Surface Passivation Technique for Low-Temperature Solution-Processed Perovskite PV Cells.

    PubMed

    Tripathi, Neeti; Shirai, Yasuhiro; Yanagida, Masatoshi; Karen, Akiya; Miyano, Kenjiro

    2016-02-24

    Low-temperature solution-processed perovskite solar cells are attracting immense interest due to their ease of fabrication and potential for mass production on flexible substrates. However, the unfavorable surface properties of planar substrates often lead to large variations in perovskite crystal size and weak charge extractions at interfaces, resulting in inferior performance. Here, we report the improved performance, reproducibility, and high stability of "p-i-n" planar heterojunction perovskite solar cells. The key fabrication process is the addition of the amine-polymer poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN-P1) to a simple spin-coating process. The PFN-P1 works as a surfactant and helps promote uniform crystallization. As a result, perovskite films with PFN-P1 have a uniform distribution of grain sizes and improved open circuit voltage. Devices with PFN-P1 showed the best efficiency (13.2%), with a small standard deviation (0.40), out of 60 cells. Moreover, ∼90% of the initial efficiency was retained over more than 6 months. Additionally, devices fabricated from PFN-P1 mixed perovskite films showed higher stability under continuous operation at maximum power point over 150 h. Our results show that this approach is simple and effective for improving device performance, reproducibility, and stability by modifying perovskite properties with PFN-P1. Because of the simplicity of the fabrication process and reliable performance increase, this approach marks important progress in low-temperature solution-processed perovskite solar cells. PMID:26821862

  18. A patient alignment solution for lung SBRT setups based on a deformable registration technique

    SciTech Connect

    Lu Bo; Mittauer, Kathryn; Li, Jonathan; Samant, Sanjiv; Dagan, Roi; Okunieff, Paul; Kahler, Darren; Liu, Chihray

    2012-12-15

    Purpose: In this work, the authors propose a novel registration strategy for translation-only correction scenarios of lung stereotactic body radiation therapy setups, which can achieve optimal dose coverage for tumors as well as preserve the consistency of registrations with minimal human interference. Methods: The proposed solution (centroid-to-centroidor CTC solution) uses the average four-dimensional CT (A4DCT) as the reference CT. The cone-beam CT (CBCT) is deformed to acquire a new centroid for the internal target volume (ITV) on the CBCT. The registration is then accomplished by simply aligning the centroids of the ITVs between the A4DCT and the CBCT. Sixty-seven cases using 64 patients (each case is associated with separate isocenters) have been investigated with the CTC method and compared with the conventional gray-value (G) mode and bone (B) mode registration methods. Dosimetric effects among the tree methods were demonstrated by 18 selected cases. The uncertainty of the CTC method has also been studied. Results: The registration results demonstrate the superiority of the CTC method over the other two methods. The differences in the D99 and D95 ITV dose coverage between the CTC method and the original plan is small (within 5%) for all of the selected cases except for one for which the tumor presented significant growth during the period between the CT scan and the treatment. Meanwhile, the dose coverage differences between the original plan and the registration results using either the B or G method are significant, as tumor positions varied dramatically, relative to the rib cage, from their positions on the original CT. The largest differences between the D99 and D95 dose coverage of the ITV using the B or G method versus the original plan are as high as 50%. The D20 differences between any of the methods versus the original plan are all less than 2%. Conclusions: The CTC method can generate optimal dose coverage to tumors with much better consistency

  19. Novel frequency domain techniques and advances in Finite Difference Time domain (FDTD) method for efficient solution of multiscale electromagnetic problems

    NASA Astrophysics Data System (ADS)

    Panayappan, Kadappan

    With the advent of sub-micron technologies and increasing awareness of Electromagnetic Interference and Compatibility (EMI/EMC) issues, designers are often interested in full- wave solutions of complete systems, taking to account a variety of environments in which the system operates. However, attempts to do this substantially increase the complexities involved in computing full-wave solutions, especially when the problems involve multi- scale geometries with very fine features. For such problems, even the well-established numerical methods, such as the time domain technique FDTD and the frequency domain methods FEM and MoM, are often challenged to the limits of their capabilities. In an attempt to address such challenges, three novel techniques have been introduced in this work, namely Dipole Moment (DM) Approach, Recursive Update in Frequency Domain (RUFD) and New Finite Difference Time Domain ( vFDTD). Furthermore, the efficacy of the above techniques has been illustrated, via several examples, and the results obtained by proposed techniques have been compared with other existing numerical methods for the purpose of validation. The DM method is a new physics-based approach for formulating MoM problems, which is based on the use of dipole moments (DMs), as opposed to the conventional Green's functions. The absence of the Green's functions, as well as those of the vector and scalar potentials, helps to eliminate two of the key sources of difficulties in the conventional MoM formulation, namely the singularity and low-frequency problems. Specifically, we show that there are no singularities that we need to be concerned with in the DM formulation; hence, this obviates the need for special techniques for integrating these singularities. Yet another salutary feature of the DM approach is its ability to handle thin and lossy structures, or whether they are metallic, dielectric-type, or even combinations thereof. We have found that the DM formulation can handle these

  20. Perovskite solar cells with a planar heterojunction structure prepared using room-temperature solution processing techniques

    NASA Astrophysics Data System (ADS)

    Liu, Dianyi; Kelly, Timothy L.

    2014-02-01

    Organic-inorganic hybrid solar cells that combine a mesoporous scaffold, a perovskite light absorber and an organic hole transporter have emerged at the forefront of solution-processable photovoltaic devices; however, they require processing temperatures of up to 500 °C to sinter the mesoporous metal-oxide support. Here, we report the use of a thin film of ZnO nanoparticles as an electron-transport layer in CH3NH3PbI3-based solar cells; in contrast to mesoporous TiO2, the ZnO layer is both substantially thinner and requires no sintering. We took advantage of these facts to prepare flexible solar cells with power-conversion efficiencies in excess of 10%. The use of ZnO also results in improvements to device performance for cells prepared on rigid substrates. Solar cells based on this design exhibit power-conversion efficiencies as high as 15.7% when measured under AM1.5G illumination, which makes them some of the highest-performing perovskite solar cells reported to date.

  1. Electrical, optical and magnetic investigations on LiNiPO{sub 4} based olivines synthesized by solution combustion technique

    SciTech Connect

    Vijayan, Lakshmi; Cheruku, Rajesh; Govindaraj, G.

    2014-02-01

    Highlights: • Solution combustion technique and preparation of nanocrystalline olivine materials. • Olivine type LiNiPO{sub 4} based nanocrystalline materials and characterization. • AC electrical studies on olivine type LiNi{sub 1−x}M{sub x}PO{sub 4}(M = Cu{sup 2+}/Mg{sup 2+})based materials. • Enhancement of ionic conductivity in the nanocrystalline phase of LiNiPO{sub 4} material. - Abstract: Citric acid assisted solution combustion technique is explored for synthesis of supervalent Cu{sup 2+}/Mg{sup 2+} ion doped LiNiPO{sub 4} system. XRD, FT-IR and microscopy studies confirmed the formation of a well crystallized material at low concentration of dopants. Ionic conductivity increases for lower concentrations of dopants due to the increased channel size for Li{sup +} diffusion. Owing to inherent anti-site defects, ionic conductivity decreases with increase of dopant concentration. Magnetic studies are explored for confirmation of antiferromagnetic nature of ions. Wagner polarization method is used to elucidate the negligible contribution of electrons to total conductivity.

  2. Light Scattering by Gaussian Particles: A Solution with Finite-Difference Time Domain Technique

    NASA Technical Reports Server (NTRS)

    Sun, W.; Nousiainen, T.; Fu, Q.; Loeb, N. G.; Videen, G.; Muinonen, K.

    2003-01-01

    The understanding of single-scattering properties of complex ice crystals has significance in atmospheric radiative transfer and remote-sensing applications. In this work, light scattering by irregularly shaped Gaussian ice crystals is studied with the finite-difference time-domain (FDTD) technique. For given sample particle shapes and size parameters in the resonance region, the scattering phase matrices and asymmetry factors are calculated. It is found that the deformation of the particle surface can significantly smooth the scattering phase functions and slightly reduce the asymmetry factors. The polarization properties of irregular ice crystals are also significantly different from those of spherical cloud particles. These FDTD results could provide a reference for approximate light-scattering models developed for irregular particle shapes and can have potential applications in developing a much simpler practical light scattering model for ice clouds angular-distribution models and for remote sensing of ice clouds and aerosols using polarized light. (copyright) 2003 Elsevier Science Ltd. All rights reserved.

  3. Development of iterative techniques for the solution of unsteady compressible viscous flows

    NASA Technical Reports Server (NTRS)

    Sankar, Lakshmi N.; Hixon, Duane

    1992-01-01

    A research effort was initiated at Georgia Tech in February 1991 on the development of efficient techniques for the computation of 2-D and 3-D unsteady compressible flow problems. It was found that in 2-D unsteady viscous flow applications, the generalized minimal residual (GMRES) scheme was able to significantly improve the accuracy and stability characteristics of an existing 2-D ADI (Alternating Direction Implicit) time marching scheme. That is, the GMRES/ADI combination allowed 10 to 20 times larger time steps compared to an ADI scheme. Because the GMRES algorithm requires 5 to 10 times the CPU work compared to the ADI scheme, the combined GMRES/ADI scheme yields a net factor of 2 savings in CPU cost. During the past year, we also experimented with GMRES/multigrid/ADI combination. The purpose of this combination was to compute the low frequency components of the change in the flow properties from one time step to the next on a coarse grid. This strategy reduces the memory requirements of the GMRES method roughly by a factor of 4-8 for steady flow problems.

  4. Application of poly (ethyleneimine) solution as a binding agent in DGT technique for measurement of heavy metals in water.

    PubMed

    Sui, Dian-Peng; Fan, Hong-Tao; Li, Jing; Li, You; Li, Qiong; Sun, Ting

    2013-09-30

    A 0.050 mol L(-1) solution of poly (ethyleneimine) (PEI), had been used as a novel binding agent of diffusive gradients in thin-films (DGT) technique (PEI-DGT) for measuring the concentrations of labile Cu(2+), Cd(2+) and Pb(2+) in waters. The binding capacities of the PEI-DGT for Cu(2+), Cd(2+) and Pb(2+) were 11.8, 10.2 and 10.6 μmol L(-1), respectively. The performance of PEI-DGT was independence of pH in the range of 4-8 and ionic strength in the range from 1×10(-4) to 0.1 mol L(-1) (as NaNO3). PEI-DGT could measure 104.7±5.2% of the total concentration of Cd(2+) (0.500 mg L(-1)), 95.2±4.3% of the total Cu(2+) (0.500 mg L(-1)) and 99.2±3.4% of the total Pb(2+) (0.500 mg L(-1)) in synthetic solution. Effects of the ligands on the measurement of labile metals were also investigated in synthetic solutions containing the various concentrations of EDTA and humic acid. In EDTA solution, the concentrations of labile metals measured by PEI-DGT showed good agreement with the theoretical concentrations of free metal ions. In humic acid solution, the concentrations of labile metals measured by PEI-DGT decreased with the increase of the concentrations of humic acid. Several DGT devices with various binding agents, including PEI, sodium polyacrylate and poly(4-styrenesulfonate) solution, were used for the measurement of labile fractions of Cu(2+), Cd(2+) and Pb(2+) in the spiked waters and in mine wastewaters. The results showed that the concentrations of labile metal measured by DGT devices with different binding agents could be significantly different, indicating that the labile fractions of metals were dependent on the binding strength of the binding agents with metals. By choosing binding agents, the useful information on the speciation and bioavailability of the analytes can be provided. PMID:23953471

  5. A Fluorescence Recovery After Photobleaching (FRAP) Technique for the Measurement of Solute Transport Across Surfactant-Laden Interfaces

    NASA Technical Reports Server (NTRS)

    Browne, Edward P.; Hatton, T. Alan

    1996-01-01

    The technique of Fluorescence Recovery After Photobleaching (FRAP) has been applied to the measurement of interfacial transport in two-phase systems. FRAP exploits the loss of fluorescence exhibited by certain fluorophores when over-stimulated (photobleached), so that a two-phase system, originally at equilibrium, can be perturbed without disturbing the interface by strong light from an argon-ion laser and its recovery monitored by a microscope-mounted CCD camera as it relaxes to a new equilibrium. During this relaxation, the concentration profiles of the probe solute are measured on both sides of the interface as a function of time, yielding information about the transport characteristics of the system. To minimize the size of the meniscus between the two phases, a photolithography technique is used to selectively treat the glass walls of the cell in which the phases are contained. This allows concentration measurements to be made very close to the interface and increases the sensitivity of the FRAP technique.

  6. Multidrug-resistant Salmonella enterica Serovar Typhimurium Monophasic Variant 4,12:i:- Isolated from Asymptomatic Wildlife in a Catalonian Wildlife Rehabilitation Center, Spain.

    PubMed

    Molina-López, Rafael A; Vidal, Anna; Obón, Elena; Martín, Marga; Darwich, Laila

    2015-07-01

    Wildlife can act as long-term asymptomatic reservoirs for zoonotic bacteria, such as Salmonella. The prevalence and antimicrobial-susceptibility profiles of Salmonella spp. were assessed in 263 cases in wildlife from 22 animal orders from a wildlife rehabilitation center in Catalonia (NE Spain), September 2013-May 2014. Eleven of 263 tested animals were positive for Salmonella spp., representing an overall prevalence of 4.2%. Prevalences by taxonomic categories were 2% in mammals, 4.7% in birds, and 4.5% in reptiles. By species, one each of European hedgehog (Erinaceus europeus; from a sample of n = 26), Eurasian Eagle Owl (Bubo bubo; n = 2), Barn Owl (Tyto alba; n = 3), Tawny Owl (Strix aluco; n = 20), Egyptian Vulture (Neophron percnopterus; n = 1), Griffon Vulture (Gyps fulvus; n = 1), and Hoopoe (Upupa epops; n = 2), and two each Common Kestrels (Falco tinnunculus; n = 16) and pond sliders (Trachemys scripta; n = 25) were positive for Salmonella. By serotyping, seven of eleven isolates were classified as S. enterica subsp. enterica serovar Typhimurium, and five of seven belonged to the monophasic variant 4,12:i:-. All the monophasic variants were isolated from birds (4/5 in raptors) and showed a multidrug-resistance (MDR) profile to at least ampicillin, streptomycin, sulfonamide, and tetracycline (R-type ASSuT), and up to 12 antibiotics. The large proportion of S. Typhimurium monophasic MDR strains detected in wildlife never treated with antibiotics, especially in raptors, adds more complexity to the epidemiologic control of one of the most frequent serovars involved in human and livestock infection. PMID:25973627

  7. A three dimensional Green's function solution technique for the transport of heavy ions in laboratory and space

    NASA Astrophysics Data System (ADS)

    Gerstner, Candice Rockell

    In the future, astronauts will be sent into space for longer durations of time compared to previous missions. The increased risk of exposure to ionizing radiation, such as Galactic Cosmic Rays and Solar Particle Events, is of great concern. Consequently, steps must be taken to ensure astronaut safety by providing adequate shielding. The shielding and exposure of space travelers is controlled by the transport properties of the radiation through the spacecraft, its onboard systems and the bodies of the individuals themselves. Meeting the challenge of future space programs will therefore require accurate and efficient methods for performing radiation transport calculations to analyze and predict shielding requirements. One such method, which is developed in this dissertation, is based on a three dimensional Green's function solution technique for the transport of heavy ions in both laboratory and space.

  8. Drug and vehicle deposition from topical applications: use of in vitro mass balance technique with minoxidil solutions.

    PubMed

    Tsai, J C; Cappel, M J; Flynn, G L; Weiner, N D; Kreuter, J; Ferry, J J

    1992-08-01

    The disposition of minoxidil and propylene glycol from topical solutions was measured by using an in vitro mass balance technique. The experimental approach included assessment of the following compartments of the skin and the diffusion cell as a function of time: (1) donor compartment; (2) hairless mouse skin surface, epidermis, and dermis; and (3) receiver compartment. Excellent mass balance was achieved for minoxidil at three doses. However, the recovery of propylene glycol depended on both application volume and time. The experiment involving the evaporation of propylene glycol and water from the propylene glycol:ethanol:water (20:60:20, v/v) mixture, which was placed in the well of a tissue culture plate at room temperature and 37 degrees C, substantiated the loss of vehicles to the air. When a thin application of 20 microL/cm2 was used, 60% of the propylene glycol was unaccounted for after 16 h. The evaporation of propylene glycol concentrated the solution to supersaturation, precipitated out the drug, and then stabilized the thermodynamic activity of the drug in the vehicle. The amount of formulation applied influences the rate of concentration and, thus, the time at which minoxidil precipitates. The precipitation limits the amount of minoxidil that can be absorbed and leads to poor percutaneous absorption of drug from the formulation. PMID:1403715

  9. Charging behavior of the gibbsite basal (001) surface in NaCl solution investigated by AFM colloidal probe technique.

    PubMed

    Gan, Yang; Franks, George V

    2006-07-01

    The charging behavior of the gibbsite gamma-Al(OH)3 basal (001) surface in aqueous solution is important for correctly modeling the overall charging properties of gibbsite particles which controls surface phenomena such as adsorption and crystal growth. However, the question of whether the hydroxyl groups on the basal plane are proton active has been raised recently both from experimental and theoretical points of view. Using gibbsite crystals prepared from industrial Bayer process, the surface potentials of cleaved (001) surfaces were calculated from forces measured by the colloidal probe technique in 1 mM NaCl solution with differing pH. It was surprisingly found that the basal plane is proton active in pH less than 7 and protonation seems to level off at about pH 5. The potential-pH data was accurately fitted with a single pKa surface protonation model with pK(a) = 5.9 +/- 0.2. PMID:16800663

  10. Physical chemistry of freeze-drying: measurement of sublimation rates for frozen aqueous solutions by a microbalance technique.

    PubMed

    Pikal, M J; Shah, S; Senior, D; Lang, J E

    1983-06-01

    The sublimation rate of frozen solutions was studied as a function of freezing rate, thickness of dried product (l), temperature, residual air pressure, and solute concentration. Data are presented for pure water, aqueous potassium chloride, aqueous povidone, and aqueous dobutamine hydrochloride-mannitol (System I). The resistance of the dried product to water vapor flow (Rp) was evaluated from the sublimation rate and the sample temperature. The primary experimental technique was based on freeze-drying a cylindrical microsample isothermally, with the sample suspended from one arm of a vacuum microbalance. Methodology to evaluate resistance data from vial freeze-drying experiments is also described. In separate experiments, samples in the form of a thin (15-microns) film were visually observed through a microscope during freeze-drying. Freeze-drying of most samples appeared to occur by water vapor escaping through open channels created by prior sublimation of ice. Contrary to the usual theoretical model, Rp is neither independent of temperature nor directly proportional to l. Rather, Rp decreases with increasing temperature and the l dependence is normally of the form Rp = (A0 + A1l)/(1 + A2l), where Ai (i = 0, 1, 2) are constants. In several cases, Rp is very large near l = 0, decreases sharply at l congruent to 0.1 cm, and obeys the above equation where l greater than 0.2 cm, a result suggesting an amorphous surface skin which cracks on desorption of water. The temperature dependence of Rp suggests that, as the sample temperature approaches the eutectic (or collapse) temperature, hydrodynamic surface flow of adsorbed water is an important flow mechanism. PMID:6875825

  11. Efficacy of nano-hydroxyapatite prepared by an aqueous solution combustion technique in healing bone defects of goat.

    PubMed

    Nandi, Samit Kumar; Kundu, Biswanath; Ghosh, Samir Kumar; De, Dipak Kumar; Basu, Debabrata

    2008-06-01

    The present study was undertaken to evaluate porous hydroxyapatite (HAp), the powder of which was prepared by a novel aqueous solution combustion technique, as a bone substitute in healing bone defects in vivo, as assessed by radiologic and histopathologic methods, oxytetracycline labeling, and angiogenic features in Bengal goat. Bone defects were created in the diaphysis of the radius and either not filled (group I) or filled with a HAp strut (group II). The radiologic study in group II showed the presence of unabsorbed implants which acted as a scaffold for new bone growth across the defect, and the quality of healing of the bone defect was almost indistinguishable from the control group, in which the defect was more or less similar, although the newly formed bony tissue was more organized when HAp was used. Histologic methods showed complete normal ossification with development of Haversian canals and well-defined osteoblasts at the periphery in group II, whereas the control group had moderate fibro-collagenization and an adequate amount of marrow material, fat cells, and blood vessels. An oxytetracycline labeling study showed moderate activity of new bone formation with crossing-over of new bone trabeculae along with the presence of resorption cavities in group II, whereas in the control group, the process of new bone formation was active from both ends and the defect site appeared as a homogenous non-fluoroscent area. Angiograms of the animals in the control group showed uniform angiogenesis in the defect site with establishment of trans-transplant angiogenesis, whereas in group II there was complete trans-transplant shunting of blood vessel communication. Porous HAp ceramic prepared by an aqueous combustion technique promoted bone formation over the defect, confirming their biologic osteoconductive property. PMID:18487940

  12. Efficacy of nano-hydroxyapatite prepared by an aqueous solution combustion technique in healing bone defects of goat

    PubMed Central

    Nandi, Samit Kumar; Ghosh, Samir Kumar; De, Dipak Kumar; Basu, Debabrata

    2008-01-01

    The present study was undertaken to evaluate porous hydroxyapatite (HAp), the powder of which was prepared by a novel aqueous solution combustion technique, as a bone substitute in healing bone defects in vivo, as assessed by radiologic and histopathologic methods, oxytetracycline labeling, and angiogenic features in Bengal goat. Bone defects were created in the diaphysis of the radius and either not filled (group I) or filled with a HAp strut (group II). The radiologic study in group II showed the presence of unabsorbed implants which acted as a scaffold for new bone growth across the defect, and the quality of healing of the bone defect was almost indistinguishable from the control group, in which the defect was more or less similar, although the newly formed bony tissue was more organized when HAp was used. Histologic methods showed complete normal ossification with development of Haversian canals and well-defined osteoblasts at the periphery in group II, whereas the control group had moderate fibro-collagenization and an adequate amount of marrow material, fat cells, and blood vessels. An oxytetracycline labeling study showed moderate activity of new bone formation with crossing-over of new bone trabeculae along with the presence of resorption cavities in group II, whereas in the control group, the process of new bone formation was active from both ends and the defect site appeared as a homogenous non-fluoroscent area. Angiograms of the animals in the control group showed uniform angiogenesis in the defect site with establishment of trans-transplant angiogenesis, whereas in group II there was complete trans-transplant shunting of blood vessel communication. Porous HAp ceramic prepared by an aqueous combustion technique promoted bone formation over the defect, confirming their biologic osteoconductive property. PMID:18487940

  13. An adaptive high-dimensional stochastic model representation technique for the solution of stochastic partial differential equations

    SciTech Connect

    Ma Xiang; Zabaras, Nicholas

    2010-05-20

    A computational methodology is developed to address the solution of high-dimensional stochastic problems. It utilizes high-dimensional model representation (HDMR) technique in the stochastic space to represent the model output as a finite hierarchical correlated function expansion in terms of the stochastic inputs starting from lower-order to higher-order component functions. HDMR is efficient at capturing the high-dimensional input-output relationship such that the behavior for many physical systems can be modeled to good accuracy only by the first few lower-order terms. An adaptive version of HDMR is also developed to automatically detect the important dimensions and construct higher-order terms using only the important dimensions. The newly developed adaptive sparse grid collocation (ASGC) method is incorporated into HDMR to solve the resulting sub-problems. By integrating HDMR and ASGC, it is computationally possible to construct a low-dimensional stochastic reduced-order model of the high-dimensional stochastic problem and easily perform various statistic analysis on the output. Several numerical examples involving elementary mathematical functions and fluid mechanics problems are considered to illustrate the proposed method. The cases examined show that the method provides accurate results for stochastic dimensionality as high as 500 even with large-input variability. The efficiency of the proposed method is examined by comparing with Monte Carlo (MC) simulation.

  14. Influence of solution deposition rate on properties of V2O5 thin films deposited by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Abd-Alghafour, N. M.; Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M.

    2016-07-01

    Vanadium oxide (V2O5) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl3 in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films' crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V2O5 film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

  15. Use of a molecular form technique for the penetration of supersaturated solutions of salicylic acid across silicone membranes and human skin in vitro.

    PubMed

    Leveque, N; Raghavan, S L; Lane, M E; Hadgraft, J

    2006-08-01

    Permeation enhancement of salicylic acid (SA) from supersaturated solutions formed using a 'molecular form' technique was investigated. In a conventional cosolvent technique, two solvents are used, one in which the drug is considerably more soluble than the other. Propylene glycol and water have been predominantly used as cosolvents to create supersaturation in skin permeation enhancement. In this paper, we report the use of buffer solutions with different pHs as media for producing different molecular forms. Supersaturated solutions were prepared using pH 8:pH 2 (80:20 v/v), which gave a nominal pH when mixed of around 5. Model silicone membranes and human skin were used. Hydroxypropyl methyl cellulose (HPMC) was employed to stabilise the supersaturated states. Stability data showed that while the SA supersaturated solutions without HPMC crystallised between 15 min and 46 h depending on the degree of supersaturation, the solutions with HPMC were stable for more than 2 months. The flux of SA increased with the degree of saturation for solutions prepared in a 80:20 buffer pH 8/buffer pH 2 mixture. Although the fluxes of SA with and without HPMC were similar both through silicone membrane and human skin, HPMC was found to be effective in increasing the stability of supersaturated solutions of SA. PMID:16650701

  16. Influence of instrumentation techniques and irrigating solutions on bond strength of glass fiber posts to root dentin.

    PubMed

    Marques, Eduardo Fernandes; Bueno, Carlos Eduardo da Silveira; Veloso, Heloisa Helena Pinho; Almeida, Gustavo; Pinheiro, Sergio Luiz

    2014-01-01

    This study sought to evaluate how instrumentation techniques and irrigating solutions affected the bond strength of glass fiber posts. For this study, 80 human maxillary central incisors were selected. Endodontic access was obtained, root canal length was measured, and the coronal third was prepared using Gates-Glidden drills. The specimens were embedded in acrylic resin and randomly assigned to 8 groups (n = 10): manual instrumentation only (Group 1), rotary instrumentation only (Group 2), irrigation with 2.5% sodium hypochlorite (NaOCl) (Group 3), irrigation with 2% chlorhexidine (CHX) (Group 4), manual instrumentation and irrigation with 2.5% NaOCl (Group 5), manual instrumentation and irrigation with 2% CHX (Group 6), rotary instrumentation and irrigation with 2.5% NaOCl (Group 7), and rotary instrumentation and irrigation with 2% CHX (Group 8). Specimens in Groups 5-8 also received a 1 minute final rinse with ethylenediaminetetraacetic acid. Canals were filled and the specimens stored for 30 days in distilled water. The restoration material was removed down to the apical 4 mm of the root canal. The glass fiber posts were luted with resin cement and stored for 24 hours at 37°C. Specimens were subjected to a tensile strength test at a constant speed of 1.0 mm/minute and a load of 2,000 kgf. The results were analyzed by analysis of variance and Tukey's test. Irrigation with 2.5% NaOCl reduced the bond strength of fiber posts significantly (P < 0.01), while CHX showed no effect (P > 0.05). It was concluded that irrigation with 2.5% NaOCl has a negative effect on micromechanical retention of glass fiber posts, whether manual or rotary instrumentation is used. PMID:24598496

  17. Development of an analytical technique for the detection of alteration minerals formed in bentonite by reaction with alkaline solutions

    NASA Astrophysics Data System (ADS)

    Sakamoto, H.; Shibata, M.; Owada, H.; Kaneko, M.; Kuno, Y.; Asano, H.

    and 50.1°, Cu Kα) of the C-S-H gel, which could not be distinguished before the heavy liquid separation, were clearly identified by XRD after separation. The result of the analyses of the light density fraction indicates highest recovery of C-S-H gel and least inclusion of bentonite for separation using heavy liquid with a specific gravity of 2.10 g/cm 3. The traces of bentonite minerals included in the suspension were identified to be montmorillonite, quartz, clinoptilolite, and calcite. The separation technique was also tested for Ca-bentonite prepared by passing a calcium hydroxide solution through a bentonite (Kunigel V1)-silica sand mixture. The results indicated that the technique would also be applicable to separation of C-S-H gel from Ca-bentonite.

  18. The use of multigrid techniques in the solution of the Elrod algorithm for a dynamically loaded journal bearing. M.S. Thesis. Final Report

    NASA Technical Reports Server (NTRS)

    Woods, Claudia M.

    1988-01-01

    A numerical solution to a theoretical model of vapor cavitation in a dynamically loaded journal bearing is developed, utilizing a multigrid iterative technique. The code is compared with a presently existing direct solution in terms of computational time and accuracy. The model is based on the Elrod algorithm, a control volume approach to the Reynolds equation which mimics the Jakobssen-Floberg and Olsson cavitation theory. Besides accounting for a moving cavitation boundary and conservation of mass at the boundary, it also conserves mass within the cavitated region via liquid striations. The mixed nature of the equations (elliptic in the full film zone and nonelliptic in the cavitated zone) coupled with the dynamic aspects of the problem create interesting difficulties for the present solution approach. Emphasis is placed on the methods found to eliminate solution instabilities. Excellent results are obtained for both accuracy and reduction of computational time.

  19. Evaluation of surface detail reproduction, dimensional stability and gypsum compatibility of monophase polyvinyl-siloxane and polyether elastomeric impression materials under dry and moist conditions

    PubMed Central

    Vadapalli, Sriharsha Babu; Atluri, Kaleswararao; Putcha, Madhu Sudhan; Kondreddi, Sirisha; Kumar, N. Suman; Tadi, Durga Prasad

    2016-01-01

    Objectives: This in vitro study was designed to compare polyvinyl-siloxane (PVS) monophase and polyether (PE) monophase materials under dry and moist conditions for properties such as surface detail reproduction, dimensional stability, and gypsum compatibility. Materials and Methods: Surface detail reproduction was evaluated using two criteria. Dimensional stability was evaluated according to American Dental Association (ADA) specification no. 19. Gypsum compatibility was assessed by two criteria. All the samples were evaluated, and the data obtained were analyzed by a two-way analysis of variance (ANOVA) and Pearson's Chi-square tests. Results: When surface detail reproduction was evaluated with modification of ADA specification no. 19, both the groups under the two conditions showed no significant difference statistically. When evaluated macroscopically both the groups showed statistically significant difference. Results for dimensional stability showed that the deviation from standard was significant among the two groups, where Aquasil group showed significantly more deviation compared to Impregum group (P < 0.001). Two conditions also showed significant difference, with moist conditions showing significantly more deviation compared to dry condition (P < 0.001). The results of gypsum compatibility when evaluated with modification of ADA specification no. 19 and by giving grades to the casts for both the groups and under two conditions showed no significant difference statistically. Conclusion: Regarding dimensional stability, both impregum and aquasil performed better in dry condition than in moist; impregum performed better than aquasil in both the conditions. When tested for surface detail reproduction according to ADA specification, under dry and moist conditions both of them performed almost equally. When tested according to macroscopic evaluation, impregum and aquasil performed significantly better in dry condition compared to moist condition. In dry

  20. Analytical solution of the advection-diffusion transport equation using a change-of-variable and integral transform technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper presents a formal exact solution of the linear advection-diffusion transport equation with constant coefficients for both transient and steady-state regimes. A classical mathematical substitution transforms the original advection-diffusion equation into an exclusively diffusive equation. ...

  1. Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol in comparison to one containing levonorgestrel and ethinylestradiol on markers of endocrine function

    PubMed Central

    Ågren, Ulla M; Anttilat, Marjatta; Mäenpää-Liukko, Kristiina; Rantala, Maija-Liisa; Rautiainen, Hilkka; Sommer, Werner F; Mommers, Ellen

    2011-01-01

    Objectives To compare the effects of two monophasic combined oral contraceptives, containing either nomegestrol acetate/17β-oestradiol (NOMAC/E2) or levonorgestrel/ ethinylestradiol (LNG/EE) on endocrine function, androgens, and sex hormone-binding globulin (SHBG). Methods Randomised, open-label, multi-centre trial involving 121 healthy women, aged 18-50 years old. Participants received NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n = 60) or LNG/EE (150 μg/30 μg) in a 21/7-day regimen (n = 61) for six cycles. The primary outcome was the change from baseline to cycle 6 in markers of adrenal and thyroid function, androgens, and SHBG. Results Total cortisol, corticosteroid-binding globulin (CBG), and thyroxine-binding globulin (TBG) increased from baseline in both groups, with significantly greater increases in the LNG/EE group. No relevant changes from baseline or differences between the groups were observed for thyroid-stimulating hormone (TSH) and free thyroxine (T4). Androgens and androgen precursors decreased from baseline in both groups, with significantly greater decreases in the LNG/EE group (except for free testosterone). A greater increase in SHBG was observed with NOMAC/E2 than with LNG/EE. Conclusions NOMAC/E2 has significantly less influence on markers of adrenal and thyroid function and androgens than LNG/EE. The clinical relevance of these findings requires further study. PMID:21942708

  2. Maskless convex corner compensation technique on a (1 0 0) silicon substrate in a 25 wt% TMAH water solution

    NASA Astrophysics Data System (ADS)

    Smiljanić, Milče M.; Jović, Vesna; Lazić, Žarko

    2012-11-01

    A maskless convex corner compensation technique in a 25 wt% TMAH water solution at the temperature of 80 °C is presented and analyzed. The maskless convex corner compensation technique is defined as a combination of masked and maskless anisotropic etching with convex corner compensation in the form of a <1 0 0> oriented beam. This technique enables the fabrication of three-level micromachined silicon structures with compensated convex corner at the bottom of the etched structure. All the planes that appear during the etching of (1 0 0) silicon in the 25 wt% TMAH water solution at the temperature of 80 °C are determined. Analytical relations have been found to explain the etching of all exposed planes and to calculate their etch rates. Analytical relations are determined and empirically verified in order to obtain regular shapes of the three-level silicon mesa structures. A boss for a low-pressure piezoresistive sensor has been fabricated as an example of the maskless convex corner compensation technique.

  3. Retention of barium and europium radionuclides from aqueous solutions on ash-based sorbents by application of radiochemical techniques.

    PubMed

    Noli, Fotini; Kapnisti, Maria; Buema, Gabriela; Harja, Maria

    2016-10-01

    New materials were synthesized for application in sorption of radionuclides from aqueous solutions. The elaboration was performed by conversion of power plant ash using the hydrothermal method under optimum experimental conditions. Sodalite, Na-Y, and analcime were formed from ash precursor during the treatment, exhibiting thermal stability as revealed by the characterization by X-ray diffraction (XRD) and thermogravimetric differential thermal analysis (TG-DTA). The Brunauer-Emmett-Teller (BET) surface area and pore volume were determined and they presented higher values than plant ash. The ability of the new products to retain Ba and Eu radionuclides was studied in aqueous solutions using (133)Ba and (152)Eu as tracers and γ-ray spectroscopy under batch experiments. The experimental data were modeled by the Langmuir and Freundlich equations, whereas sorption kinetics measurements were performed at 293, 308, and 323K and thermodynamic parameters were calculated. The release of the sorbed ions into the environment was also tested by leaching experiments. The results of these tests indicated that the synthesized materials are very efficient in removing the aforementioned metals from aqueous solutions and can be considered as potential low-cost sorbents in nuclear waste management. PMID:27509595

  4. Improvement of Physico-mechanical Properties of Partially Amorphous Acetaminophen Developed from Hydroalcoholic Solution Using Spray Drying Technique

    PubMed Central

    Sadeghi, Fatemeh; Torab, Mansour; Khattab, Mostafa; Homayouni, Alireza; Afrasiabi Garekani, Hadi

    2013-01-01

    Objective(s): This study was performed aiming to investigate the effect of particle engineering via spray drying of hydroalcoholic solution on solid states and physico-mechanical properties of acetaminophen. Materials and Methods: Spray drying of hydroalcoholic solution (25% v/v ethanol/water) of acetaminophen (5% w/v) in the presence of small amounts of polyninylpyrrolidone K30 (PVP) (0, 1.25, 2.5 and 5% w/w based on acetaminophen weight) was carried out. The properties of spray dried particles namely morphology, surface characteristics, particle size, crystallinity, dissolution rate and compactibility were evaluated. Results: Spray drying process significantly changed the morphology of acetaminophen crystals from acicular (rod shape) to spherical microparticle. Differential scanning calorimetery (DSC) and x-ray powder diffraction (XRPD) studies ruled out any polymorphism in spray dried samples, however, a major reduction in crystallinity up to 65%, especially for those containing 5% w/w PVP was observed. Spray dried acetaminophen particles especially those obtained in the presence of PVP exhibited an obvious improvement of the dissolution and compaction properties. Tablets produced from spray dried samples exhibited excellent crushing strengths and no tendency to cap. Conclusions: The findings of this study revealed that spray drying of acetaminophen from hydroalcoholic solution in the presence of small amount of PVP produced partially amorphous particles with improved dissolution and excellent compaction properties. PMID:24379968

  5. Development of new techniques for the characterization of crystals and their growth solutions: Center director's discretionary fund

    NASA Technical Reports Server (NTRS)

    Kroes, Roger L.; Reiss, Donald A.

    1989-01-01

    The solubility measurement system and the laser scattering microscope system were designed, built, and utilized for the study of crystal growth solutions and crystal characterization measurements. Solubility measurements and crystal defect maps were made with this equipment for a number of new materials. In some cases, where there have been published solubility data (i.e., TGS), more accurate measurements were made and discrepancies in the published data were resolved. The design of these instruments is presented along with a description of their use and some typical data generated using them.

  6. Electrically conductive nanostructured silver doped zinc oxide (Ag:ZnO) prepared by solution-immersion technique

    NASA Astrophysics Data System (ADS)

    Afaah, A. N.; Asib, N. A. M.; Aadila, A.; Mohamed, R.; Rusop, M.; Khusaimi, Z.

    2016-07-01

    p-type ZnO films have been fabricated on ZnO-seeded glass substrate, using AgNO3 as a source of silver dopant by facile solution-immersion. Cleaned glass substrate were seeded with ZnO by mist-atomisation, and next the seeded substrates were immersed in Ag:ZnO solution. The effects of Ag doping concentration on the Ag-doped ZnO have been investigated. The substrates were immersed in different concentrations of Ag dopant with variation of 0, 1, 3, 5 and 7 at. %. The surface morphology of the films was characterized by field emission scanning electron microscope (FESEM). In order to investigate the electrical properties, the films were characterized by Current-Voltage (I-V) measurement. FESEM micrographs showed uniform distribution of nanostructured ZnO and Ag:ZnO. Besides, the electrical properties of Ag-doped ZnO were also dependent on the doping concentration. The I-V measurement result indicated the electrical properties of 1 at. % Ag:ZnO thin film owned highest electrical conductivity.

  7. An enhanced security solution for electronic medical records based on AES hybrid technique with SOAP/XML and SHA-1.

    PubMed

    Kiah, M L Mat; Nabi, Mohamed S; Zaidan, B B; Zaidan, A A

    2013-10-01

    This study aims to provide security solutions for implementing electronic medical records (EMRs). E-Health organizations could utilize the proposed method and implement recommended solutions in medical/health systems. Majority of the required security features of EMRs were noted. The methods used were tested against each of these security features. In implementing the system, the combination that satisfied all of the security features of EMRs was selected. Secure implementation and management of EMRs facilitate the safeguarding of the confidentiality, integrity, and availability of e-health organization systems. Health practitioners, patients, and visitors can use the information system facilities safely and with confidence anytime and anywhere. After critically reviewing security and data transmission methods, a new hybrid method was proposed to be implemented on EMR systems. This method will enhance the robustness, security, and integration of EMR systems. The hybrid of simple object access protocol/extensible markup language (XML) with advanced encryption standard and secure hash algorithm version 1 has achieved the security requirements of an EMR system with the capability of integrating with other systems through the design of XML messages. PMID:24037086

  8. Directional spectra of ocean waves from microwave backscatter: A physical optics solution with application to the short-pulse and two-frequency measurement techniques

    NASA Technical Reports Server (NTRS)

    Jackson, F. C.

    1979-01-01

    Two simple microwave radar techniques that are potentially capable of providing routine satellite measurements of the directional spectrum of ocean waves were developed. One technique, the short pulse technique, makes use of very short pulses to resolve ocean surface wave contrast features in the range direction; the other technique, the two frequency correlation technique makes use of coherency in the transmitted waveform to detect the large ocean wave contrast modulation as a beat or mixing frequency in the power backscattered at two closely separated microwave frequencies. A frequency domain analysis of the short pulse and two frequency systems shows that the two measurement systems are essentially duals; they each operate on the generalized (three frequency) fourth-order statistical moment of the surface transfer function in different, but symmetrical ways, and they both measure the same directional contrast modulation spectrum. A three dimensional physical optics solution for the fourth-order moment was obtained for backscatter in the near vertical, specular regime, assuming Gaussian surface statistics.

  9. Environmental stability of solution processed Al-doped ZnO naoparticulate thin films using surface modification technique

    NASA Astrophysics Data System (ADS)

    Vunnam, Swathi; Ankireddy, Krishnamraju; Kellar, Jon; Cross, William

    2014-12-01

    The environmental stability of solution processed Al-doped ZnO (AZO) thin films was enhanced by functionalizing the film surface with a thin self-assembled molecular layer. Functionalization of AZO films was performed using two types of molecules having identical 12-carbon alkyl chain termination but different functional groups: dodecanethiol (DDT) and dodecanoic acid (DDA). Surface modified AZO films were examined using electrical resistivity measurements, contact angle measurements and quantitative nanomechanical property mapping atomic force microscopy. The hydrophobic layer inhibits the penetration of oxygen and water into the AZO's grain boundaries thus significantly increasing the environmental stability over unmodified AZO. Surface modified AZO films using DDT exhibited lower electrical resistivity compared to DDA functionalized AZO films. Our study demonstrates a new approach for improving the physical properties of oxide based nanoparticulate films for device applications.

  10. Rapid growth of thin and flexible organic semiconductor single crystal Anthracene by solution growth technique for device fabrication

    NASA Astrophysics Data System (ADS)

    Thirupugalmani, K.; Shanmugam, G.; Kannan, V.; Brahadeeswaran, S.

    2015-03-01

    Growth of thin and flexible organic semiconductor crystal Anthracene (AN) has been achieved in a very short duration. This simple, yet an effective approach was serendipitously found to yield high quality crystal with typical dimensions of 22×23×0.15-0.50 mm3 within a duration of about 30 min whereas a conventional method could take about 7-10 days to achieve similar dimensions. Further, these crystals were seen swirling and settling down slowly at the bottom of the growth flask. These factors were favorably utilized to place the Anthracene crystals firmly on prefabricated flexible substrates when they were kept in different heights within the solutions. This systematic approach also facilitated the fabrication of organic field effect transistor (OFET) and the results obtained were encouraging.

  11. An on-site colorimetric technique for routine determination of chromium, iron and copper in bath solutions for chromium(III) conversion coating.

    PubMed

    Kawakubo, Susumu; Shimada, Katsuhisa; Suzuki, Yasutada; Hattori, Kazuya

    2011-01-01

    An on-site colorimetric technique was developed for the routine determination of chromium, iron and copper in bath solutions for the chromium(III) conversion coating. A portable colorimeter with a red-green-blue light emitting diode was used for the absorbance measurements. Iron and copper were determined as Fe(III)-thiocyanate and Cu(I)-bathocuproindisulfonate, respectively. Chromium(III) was determined simultaneously with iron or copper using green and blue light. A correction method of the matrix effect was proposed and its applicability was demonstrated. Analytical errors were within 500, 5 and 0.3 mg L(-1) for chromium(III), iron and copper, respectively. PMID:21415522

  12. Classifying fractionated electrograms in human atrial fibrillation using monophasic action potentials and activation mapping: Evidence for localized drivers, rate acceleration, and nonlocal signal etiologies

    PubMed Central

    Narayan, Sanjiv M.; Wright, Matthew; Derval, Nicolas; Jadidi, Amir; Forclaz, Andrei; Nault, Isabelle; Miyazaki, Shinsuke; Sacher, Frédéric; Bordachar, Pierre; Clémenty, Jacques; Jaïs, Pierre; Haïssaguerre, Michel; Hocini, Mélèze

    2011-01-01

    BACKGROUND Complex fractionated electrograms (CFAEs) detected during substrate mapping for atrial fibrillation (AF) reflect etiologies that are difficult to separate. Without knowledge of local refractoriness and activation sequence, CFAEs may represent rapid localized activity, disorganized wave collisions, or far-field electrograms. OBJECTIVE The purpose of this study was to separate CFAE types in human AF, using monophasic action potentials (MAPs) to map local refractoriness in AF and multipolar catheters to map activation sequence. METHODS MAP and adjacent activation sequences at 124 biatrial sites were studied in 18 patients prior to AF ablation (age 57 ± 13 years, left atrial diameter 45 ± 8 mm). AF cycle length, bipolar voltage, and spectral dominant frequency were measured to characterize types of CFAE. RESULTS CFAE were observed at 91 sites, most of which showed discrete MAPs and (1) pansystolic local activity (8%); (2) CFAE after AF acceleration, often with MAP alternans (8%); or (3) nonlocal (far-field) signals (67%). A fourth CFAE pattern lacked discrete MAPs (17%), consistent with spatial disorganization. CFAE with discrete MAPs and pansystolic activation (consistent with rapid localized AF sites) had shorter cycle length (P <.05) and lower voltage (P <.05) and trended to have higher dominant frequency than other CFAE sites. Many CFAEs, particularly at the septa and coronary sinus, represented far-field signals. CONCLUSION CFAEs in human AF represent distinct functional types that may be separated using MAPs and activation sequence. In a minority of cases, CFAEs indicate localized rapid AF sites. The majority of CFAEs reflect far-field signals, AF acceleration, or disorganization. These results may help to interpret CFAE during AF substrate mapping. PMID:20955820

  13. Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol compared with one containing levonorgestrel and ethinylestradiol on haemostasis, lipids and carbohydrate metabolism

    PubMed Central

    Ågren, Ulla M; Anttilat, Marjatta; Mäenpää-Liukko, Kristiina; Rantala, Maija-Liisa; Rautiainen, Hilkka; Sommer, Werner F; Mommers, Ellen

    2011-01-01

    Objectives To compare the effects of a combined oral contraceptive (COC) containing nomegestrol acetate and 17β-oestradiol (NOMAC/E2) on haemostasis, lipids, carbohydrate metabolism, C-reactive protein (CRP) and sex hormone-binding globulin (SHBG) with those of a COC containing levonorgestrel and ethinylestradiol (LNG/EE). Methods In a randomised, open-label study, 121 healthy women, 18-50 years of age, were randomly assigned to receive NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n = 60) or LNG/EE (150 μg/30 μg) in a 21/7-day regimen (n = 61) for six cycles. The primary outcome was the change from baseline to cycle 6 for all indices. Results All parameters were similar at baseline between the two groups. Over six cycles, NOMAC/E2 had less effect on most haemostatic indices than LNG/EE. Lipids were essentially unchanged with NOMAC/E2, whereas with LNG/EE high-density lipoprotein cholesterol decreased and low-density lipoprotein cholesterol and triglycerides slightly increased. NOMAC/E2 induced negligible changes in glucose and insulin parameters, in contrast to LNG/EE. A much smaller increase in CRP was observed with NOMAC/E2 than with LNG/EE. NOMAC/E2 was associated with a greater increase in SHBG. Conclusions The monophasic COC NOMAC/E2 had less influence on haemostasis, lipids and carbohydrate metabolism than the COC LNG/EE. PMID:22066891

  14. Dimensional Accuracy of Hydrophilic and Hydrophobic VPS Impression Materials Using Different Impression Techniques - An Invitro Study

    PubMed Central

    Pilla, Ajai; Pathipaka, Suman

    2016-01-01

    Introduction The dimensional stability of the impression material could have an influence on the accuracy of the final restoration. Vinyl Polysiloxane Impression materials (VPS) are most frequently used as the impression material in fixed prosthodontics. As VPS is hydrophobic when it is poured with gypsum products, manufacturers added intrinsic surfactants and marketed as hydrophilic VPS. These hydrophilic VPS have shown increased wettability with gypsum slurries. VPS are available in different viscosities ranging from very low to very high for usage under different impression techniques. Aim To compare the dimensional accuracy of hydrophilic VPS and hydrophobic VPS using monophase, one step and two step putty wash impression techniques. Materials and Methods To test the dimensional accuracy of the impression materials a stainless steel die was fabricated as prescribed by ADA specification no. 19 for elastomeric impression materials. A total of 60 impressions were made. The materials were divided into two groups, Group1 hydrophilic VPS (Aquasil) and Group 2 hydrophobic VPS (Variotime). These were further divided into three subgroups A, B, C for monophase, one-step and two-step putty wash technique with 10 samples in each subgroup. The dimensional accuracy of the impressions was evaluated after 24 hours using vertical profile projector with lens magnification range of 20X-125X illumination. The study was analyzed through one-way ANOVA, post-hoc Tukey HSD test and unpaired t-test for mean comparison between groups. Results Results showed that the three different impression techniques (monophase, 1-step, 2-step putty wash techniques) did cause significant change in dimensional accuracy between hydrophilic VPS and hydrophobic VPS impression materials. One-way ANOVA disclosed, mean dimensional change and SD for hydrophilic VPS varied between 0.56% and 0.16%, which were low, suggesting hydrophilic VPS was satisfactory with all three impression techniques. However, mean

  15. Application of dye-tracing techniques for determining solute-transport characteristics of ground water in karst terranes

    SciTech Connect

    Mull, D.S.; Liebermann, T.D.; Smoot, J.L.; Woosley, L.H.

    1988-10-01

    Approximately 20% of the United States is underlain by karst aquifers. This approximation includes roughly 50% of both Kentucky and Tennessee, substantial portions of northern Georgia and Alabama, and parts of other Region IV states. The prevalence of karst aquifers in the southeast, the common use of karst aquifers as drinking water sources and the vulnerability of these aquifers to contamination highlighted the need to provide a mechanism to assist in ground-water management and protection in karst terranes. In an attempt to meet this need, the U.S. Environmental Protection Agency (EPA)--Region IV and the Kentucky District of the U.S. Geological Survey (USGS), have been cooperating to document the application of dye tracing techniques and concepts to ground-water protection in karst aquifers. These efforts have resulted in the preparation of the manual. The information presented herein should be viewed as another analytical 'tool' to assist in the management and protection of karst water supplies.

  16. On Bi-Grid Local Mode Analysis of Solution Techniques for 3-D Euler and Navier-Stokes Equations

    NASA Technical Reports Server (NTRS)

    Ibraheem, S. O.; Demuren, A. O.

    1994-01-01

    A procedure is presented for utilizing a bi-grid stability analysis as a practical tool for predicting multigrid performance in a range of numerical methods for solving Euler and Navier-Stokes equations. Model problems based on the convection, diffusion and Burger's equation are used to illustrate the superiority of the bi-grid analysis as a predictive tool for multigrid performance in comparison to the smoothing factor derived from conventional von Neumann analysis. For the Euler equations, bi-grid analysis is presented for three upwind difference based factorizations, namely Spatial, Eigenvalue and Combination splits, and two central difference based factorizations, namely LU and ADI methods. In the former, both the Steger-Warming and van Leer flux-vector splitting methods are considered. For the Navier-Stokes equations, only the Beam-Warming (ADI) central difference scheme is considered. In each case, estimates of multigrid convergence rates from the bi-grid analysis are compared to smoothing factors obtained from single-grid stability analysis. Effects of grid aspect ratio and flow skewness are examined. Both predictions are compared with practical multigrid convergence rates for 2-D Euler and Navier-Stokes solutions based on the Beam-Warming central scheme.

  17. Formalisms for Electron Exchange Kinetics in Aqueous Solution, and the Role of Ab Initio Techniques in Their Implementation

    SciTech Connect

    Newton, M.D.

    1980-01-01

    Formalisms suitable for calculating the rate of electron exchange between transition metal complexes in aqueous solution are reviewed and implemented in conjunction with ab initio quantum chemical calculations which provide crucial off-diagonal Hamiltonian matrix elements as well as other relevant electronic structural data. Rate constants and activation parameters are calculated for the hex-aquo Fe2 +-Fe3+ system, using a simple activated complex theory, a non-adiabatic semi-classical model which includes nuclear tunnelling, and a more detailed quantum mechanical method based on the Golden Rule. Comparisons are made between calculated results and those obtained by extrapolating experimental data to zero ionic strength. All methods yield similar values for the overall rate constant (∾ 0.1 L/(mol-sec)). The experimental activation parameters (δH and δS) are in somewhat better agreement with the semi classical and quantum mechanical results than with those from the simple activated complex theory, thereby providing some indication that non-adiabaticity and nuclear tunnelling may be important in the Fe2+/3+ exchange reaction. It is concluded that a model based on direct metal-metal overlap can account for the observed reaction kinetics provided the reactants are allowed to approach well within the traditional contact distance of 6.9 Å. 6 figures, 7 tables.

  18. Surelease or organic solution of ethylcellulose in preparation of sustained release theophylline micromatrices or matrices using spray drying technique.

    PubMed

    Afrasiabi Garekani, Hadi; Sedighi, Samira; Sadeghi, Fatemeh

    2015-03-01

    This study evaluated ethylcellulose (EC) in two forms in preparation of sustained release theophylline microparticles using spray drying. Spray dried (SD) samples at different drug:polymer ratios were prepared using Surelease (SDaq) or organic solutions of ethylcellulose (SDor). Properties of particles (yield, particle morphology, size distribution and release profiles) were examined. Differential scanning calorimetry (DSC) and infrared spectroscopy (IR) studies were performed to track polymorphic changes and/or drug polymer interactions. SD samples were compressed and crushing strengths and release profiles were determined. The yields were in the range of 55-70%. The SD samples were nearly spherical with numerous fine particles attached to their surfaces. The SDor samples showed the smallest particle size. No polymorphism or drug-polymer interaction was observed. Uncompressed SDaq samples showed inadequate sustained release of drug compared to SDor samples. Surelease content did not affect drug release from SDaq samples. Tablets prepared from SDaq were softer and showed some plasticity, while those prepared from SDor exhibited higher crushing strengths. Tablets prepared from SDaq showed sustained release properties while the release of drug from compressed SDor samples were too slow. Overall Surelease was unable to sustain release of theophylline from SDaq microparticles, however, in compacted form showed more appropriate drug release than compacted SDor. PMID:24286215

  19. The growth of benzophenone crystals by Sankaranarayanan-Ramasamy (SR) method and slow evaporation solution technique (SEST): A comparative investigation

    SciTech Connect

    Senthil Pandian, M.; Boopathi, K.; Ramasamy, P.; Bhagavannarayana, G.

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Benzophenone single crystal was grown by Sankaranarayanan-Ramasamy method which has the sizes of 1060 mm length and 55 mm diameter for the first time. Black-Right-Pointing-Pointer The conventional and SR-grown benzophenone crystals were characterized and compared using HRXRD, etching, laser damage threshold, microhardness, UV-transmittance, birefringence and dielectric analysis. Black-Right-Pointing-Pointer The SR-grown benzophenone crystal has higher LDT, microhardness, transparency, dielectric permittivity, birefringence and lower FWHM, EPD, dielectric loss than the crystal grown by conventional method. Black-Right-Pointing-Pointer The probable reason for higher crystalline perfection in SR-grown crystal was discussed. -- Abstract: Longest unidirectional Left-Pointing-Angle-Bracket 1 0 0 Right-Pointing-Angle-Bracket benzophenone (BP) crystal having dimension of 1060 mm length and 55 mm diameter was grown by Sankaranarayanan-Ramasamy method. The growth rate was measured by monitoring the elevation of the crystal-solution interface at different temperatures. The high resolution X-ray diffraction and etching measurements indicate that the unidirectional grown benzophenone crystal has good crystalline perfection and less density of defects. The optical damage threshold of SEST and SR grown BP crystals has been investigated and found that the SR grown benzophenone crystal has higher laser damage threshold value than the conventional method grown crystal. Microhardness measurement shows that crystals grown by SR method have a higher mechanical stability than the crystals grown by SEST method. Dielectric permittivity and birefringence are high in SR grown crystal compared to SEST grown BP crystal. The UV-vis-NIR results show that SR method grown crystal exhibits 7% higher transmittance as against crystals grown by conventional method.

  20. Physicochemical, bioactive, and sensory properties of persimmon-based ice cream: technique for order preference by similarity to ideal solution to determine optimum concentration.

    PubMed

    Karaman, Safa; Toker, Ömer Said; Yüksel, Ferhat; Çam, Mustafa; Kayacier, Ahmed; Dogan, Mahmut

    2014-01-01

    In the present study, persimmon puree was incorporated into the ice cream mix at different concentrations (8, 16, 24, 32, and 40%) and some physicochemical (dry matter, ash, protein, pH, sugar, fat, mineral, color, and viscosity), textural (hardness, stickiness, and work of penetration), bioactive (antiradical activity and total phenolic content), and sensory properties of samples were investigated. The technique for order preference by similarity to ideal solution approach was used for the determination of optimum persimmon puree concentration based on the sensory and bioactive characteristics of final products. Increase in persimmon puree resulted in a decrease in the dry matter, ash, fat, protein contents, and viscosity of ice cream mix. Glucose, fructose, sucrose, and lactose were determined to be major sugars in the ice cream samples including persimmon and increase in persimmon puree concentration increased the fructose and glucose content. Better melting properties and textural characteristics were observed for the samples with the addition of persimmon. Magnesium, K, and Ca were determined to be major minerals in the samples and only K concentration increased with the increase in persimmon content. Bioactive properties of ice cream samples improved and, in general, acetone-water extracts showed higher bioactivity compared with ones obtained using methanol-water extracts. The technique for order preference by similarity to ideal solution approach showed that the most preferred sample was the ice cream containing 24% persimmon puree. PMID:24268400

  1. Synthesis and characterizations of hierarchical biomorphic titania oxide by a bio-inspired bottom-up assembly solution technique

    SciTech Connect

    Dong Qun; Su Huilan Cao Wei; Zhang Di; Guo Qixin; Lai Yijian

    2007-03-15

    As a representative semiconductor metal oxide, hierarchical biomorphic mesoporous TiO{sub 2} with interwoven meshwork conformation was successfully prepared using eggshell membrane (ESM) as a biotemplate by an aqueous soakage technique followed by calcination treatment. The synthesis conditions were systematically investigated by controlling the concentration, the pH value of the precursor impregnant, and so on. The nucleation, growth, and assembly into ESM-biomorphic TiO{sub 2} in our work depended more on the functions of ESM biomacromolecules as well as the processing conditions. As-prepared TiO{sub 2} meshwork exhibiting hierarchical porous structure with the pore size from 2 nm up to 4 {mu}m, was composed of intersectant fibers assembled by nanocrystallites at three dimensions. Based on the researches into the N{sub 2} adsorption-desorption isothermal and corresponding BJH pore-size distribution, the biomorphic TiO{sub 2} would arose interesting applications in some fields such as photocatalysis, gas sensors, antistatic coating, dye-sensitized solar cells, etc. This mild method and the relevant ideas offer a feasible path to synthesize a new family of functional materials by integrating material science, chemistry, and biotechnology. - Graphical abstract: Hierarchical mesoporous TiO{sub 2} is assembled by nanoparticles from the nanoscale to the macroscale through a bio-inspired sol-gel approach with eggshell membrane used as the biotemplate. As-prepared hierarchical titania shows porous characters within the pore size range of 2 nm-4 {mu}m.

  2. Synthesis and characterizations of hierarchical biomorphic titania oxide by a bio-inspired bottom-up assembly solution technique

    NASA Astrophysics Data System (ADS)

    Dong, Qun; Su, Huilan; Cao, Wei; Zhang, Di; Guo, Qixin; Lai, Yijian

    2007-03-01

    As a representative semiconductor metal oxide, hierarchical biomorphic mesoporous TiO 2 with interwoven meshwork conformation was successfully prepared using eggshell membrane (ESM) as a biotemplate by an aqueous soakage technique followed by calcination treatment. The synthesis conditions were systematically investigated by controlling the concentration, the pH value of the precursor impregnant, and so on. The nucleation, growth, and assembly into ESM-biomorphic TiO 2 in our work depended more on the functions of ESM biomacromolecules as well as the processing conditions. As-prepared TiO 2 meshwork exhibiting hierarchical porous structure with the pore size from 2 nm up to 4 μm, was composed of intersectant fibers assembled by nanocrystallites at three dimensions. Based on the researches into the N 2 adsorption-desorption isothermal and corresponding BJH pore-size distribution, the biomorphic TiO 2 would arose interesting applications in some fields such as photocatalysis, gas sensors, antistatic coating, dye-sensitized solar cells, etc. This mild method and the relevant ideas offer a feasible path to synthesize a new family of functional materials by integrating material science, chemistry, and biotechnology.

  3. Efficacy of Neutral Electrolyzed Water, Quaternary Ammonium and Lactic Acid-Based Solutions in Controlling Microbial Contamination of Food Cutting Boards Using a Manual Spraying Technique.

    PubMed

    Al-Qadiri, Hamzah M; Ovissipour, Mahmoudreza; Al-Alami, Nivin; Govindan, Byju N; Shiroodi, Setareh Ghorban; Rasco, Barbara

    2016-05-01

    Bactericidal activity of neutral electrolyzed water (NEW), quaternary ammonium (QUAT), and lactic acid-based solutions was investigated using a manual spraying technique against Salmonella Typhimurium, Escherichia coli O157:H7, Campylobacter jejuni, Listeria monocytogenes and Staphylococcus aureus that were inoculated onto the surface of scarred polypropylene and wooden food cutting boards. Antimicrobial activity was also examined when using cutting boards in preparation of raw chopped beef, chicken tenders or salmon fillets. Viable counts of survivors were determined as log10 CFU/100 cm(2) within 0 (untreated control), 1, 3, and 5 min of treatment at ambient temperature. Within the first minute of treatment, NEW and QUAT solutions caused more than 3 log10 bacterial reductions on polypropylene surfaces whereas less than 3 log10 reductions were achieved on wooden surfaces. After 5 min of treatment, more than 5 log10 reductions were achieved for all bacterial strains inoculated onto polypropylene surfaces. Using NEW and QUAT solutions within 5 min reduced Gram-negative bacteria by 4.58 to 4.85 log10 compared to more than 5 log10 reductions in Gram-positive bacteria inoculated onto wooden surfaces. Lactic acid treatment was significantly less effective (P < 0.05) compared to NEW and QUAT treatments. A decline in antimicrobial effectiveness was observed (0.5 to <2 log10 reductions were achieved within the first minute) when both cutting board types were used to prepare raw chopped beef, chicken tenders or salmon fillets. PMID:27027449

  4. Development of an integrated BEM approach for hot fluid structure interaction: BEST-FSI: Boundary Element Solution Technique for Fluid Structure Interaction

    NASA Technical Reports Server (NTRS)

    Dargush, G. F.; Banerjee, P. K.; Shi, Y.

    1992-01-01

    As part of the continuing effort at NASA LeRC to improve both the durability and reliability of hot section Earth-to-orbit engine components, significant enhancements must be made in existing finite element and finite difference methods, and advanced techniques, such as the boundary element method (BEM), must be explored. The BEM was chosen as the basic analysis tool because the critical variables (temperature, flux, displacement, and traction) can be very precisely determined with a boundary-based discretization scheme. Additionally, model preparation is considerably simplified compared to the more familiar domain-based methods. Furthermore, the hyperbolic character of high speed flow is captured through the use of an analytical fundamental solution, eliminating the dependence of the solution on the discretization pattern. The price that must be paid in order to realize these advantages is that any BEM formulation requires a considerable amount of analytical work, which is typically absent in the other numerical methods. All of the research accomplishments of a multi-year program aimed toward the development of a boundary element formulation for the study of hot fluid-structure interaction in Earth-to-orbit engine hot section components are detailed. Most of the effort was directed toward the examination of fluid flow, since BEM's for fluids are at a much less developed state. However, significant strides were made, not only in the analysis of thermoviscous fluids, but also in the solution of the fluid-structure interaction problem.

  5. Demonstration of the ITER Power Exhaust Solution Using the Puff and Pump Technique on DIII-D

    SciTech Connect

    Wade, M.R.; West, W.P.; Hill, D.N.; Allen, S.L.; Boedo, J.A.; Brooks, N.H.; Fenstermacher, M.E.; Hogan, J.T.; Isler, R.C.; Jayakumar, R.J.; Lasnier, C.J.; Lehmer, R.; Leonard, A.W.; Maingi, R.; Moyer, R.A.; Petrie, T.W.; Schaffer, M.J.; Watkins, J.G.; Whyte, D.G.; Wood, R.D.

    1999-07-01

    In future, high power density fusion devices, the need to prevent excessive local deposition of the plasma energy efflux on the first-wall surfaces is a critical design consideration in order to maintain the integrity of such surfaces. This requirement must be met without significant impact on plasma purity or overall plasma confinement. For the International Thermonuclear Experimental Reactor (ITER), these constraints have led to the following design criteria [1] P{sub rad}/(P{sub input} + P{sub {alpha}}) = 83%, P{sub rad,core}/(P{sub input} + P{sub {alpha}}) = 33%, P{sub target}/P{sub loss} = 17%, Z{sub eff} < 1.8, and {tau}{sub E}/{tau}{sub E,ITER93H} > 0.85. Here, P{sub loss} is the power flowing out of the core (i.e., P{sub input} + P{sub {alpha}} - P{sub rad,core})and P{sub target} is the power conducted to the target plate. These criteria represent a compromise between obtaining sufficient radiation to reduce the target heat load to a tolerable level, minimizing core fuel dilution, and maintaining sufficient power flow through the edge plasma to maintain H-mode confinement. Past experiments have had difficulty achieving these conditions simultaneously when using seeded impurities, and therefore there has been some concern regarding the viability of the ITER design. However, recent experiments in DIII-D using the puff and pump technique with argon as the seeded impurity have demonstrated the compatibility of these design constraints. In particular, steady-state plasma conditions have been achieved with P{sub rad}/P{sub input} = 72%, P{sub rad,core}/P{sub input} = 16%, P{sub target}/P{sub loss} = 17%, Z{sub eff} = 1.85, and {tau}{sub E}/{tau}{sub E,ITER93H} = 1.05.

  6. Optical investigations on Tb3+ doped L-Histidine hydrochloride mono hydrate single crystals grown by low temperature solution techniques

    NASA Astrophysics Data System (ADS)

    Rajyalakshmi, S.; Ramachandra Rao, K.; Brahmaji, B.; Samatha, K.; Visweswara Rao, T. K.; Bhagavannarayana, G.

    2016-04-01

    The potential nonlinear optical material of Terbium (Tb3+) ion doped L-Histidine hydrochloride monohydrate (LHHC) single crystals were successfully grown. Tb3+:LHHC crystals of 7 mm × 5 mm × 3 mm and 59 mm length and 15 mm diameter have been grown by the slow solvent evaporation and Sankaranarayanan-Ramasamy (SR) techniques respectively. The grown crystals were characterized by single crystal X-ray diffraction analysis to confirm the crystalline structure and morphology. High resolution X-ray diffraction (HRXRD) studies revealed that the SR grown sample shows relatively good crystalline nature with 9″ full-width at half-maximum (FWHM) for the diffraction curve. Functional groups were identified by Fourier transform infra-red spectroscopy (FTIR). The optical transparency and band gaps of grown crystals were measured by UV-Vis spectroscopy. Thermogravimetric and differential thermal analysis (TG/DTA) studies reveal that the crystal was thermally stable up to 155 °C in SR grown crystal. Surface morphology of the growth plane was observed using scanning electron microscopy (SEM). The incorporation of Tb ion was estimated by EDAX. The frequency-dependent dielectric properties of the crystals were carried out for different temperatures. Vickers hardness study carried out on (1 0 0) face at room temperature shows increased hardness of the SR method grown crystal. Second harmonic generation efficiency of SEST and SR grown crystals are 3.2 and 3.5 times greater than that of pure KDP. The Photoluminescence (PL) studies of Tb3+ ions result from the radiative intra-configurational f-f transitions that occur from the 5D4 excited state to the 7Fj (j = 6, 5, 4, 3) ground states. The decay curve of the 5D4 level of emission was observed with a long life time of 319.2041 μs for the SR grown Tb3+:LHHC crystal.

  7. In situ characterization of uranium and americium oxide solid solution formation for CRMP process: first combination of in situ XRD and XANES measurements.

    PubMed

    Caisso, Marie; Picart, Sébastien; Belin, Renaud C; Lebreton, Florent; Martin, Philippe M; Dardenne, Kathy; Rothe, Jörg; Neuville, Daniel R; Delahaye, Thibaud; Ayral, André

    2015-04-14

    Transmutation of americium in heterogeneous mode through the use of U1-xAmxO2±δ ceramic pellets, also known as Americium Bearing Blankets (AmBB), has become a major research axis. Nevertheless, in order to consider future large-scale deployment, the processes involved in AmBB fabrication have to minimize fine particle dissemination, due to the presence of americium, which considerably increases the risk of contamination. New synthesis routes avoiding the use of pulverulent precursors are thus currently under development, such as the Calcined Resin Microsphere Pelletization (CRMP) process. It is based on the use of weak-acid resin (WAR) microspheres as precursors, loaded with actinide cations. After two specific calcinations under controlled atmospheres, resin microspheres are converted into oxide microspheres composed of a monophasic U1-xAmxO2±δ phase. Understanding the different mechanisms during thermal conversion, that lead to the release of organic matter and the formation of a solid solution, appear essential. By combining in situ techniques such as XRD and XAS, it has become possible to identify the key temperatures for oxide formation, and the corresponding oxidation states taken by uranium and americium during mineralization. This paper thus presents the first results on the mineralization of (U,Am) loaded resin microspheres into a solid solution, through in situ XAS analysis correlated with HT-XRD. PMID:25742991

  8. Apollo management: A key to the solution of the social-economical dilemma - The transferability of space-travel managerial techniques to the civil sector

    NASA Technical Reports Server (NTRS)

    Puttkamer, J. V.

    1973-01-01

    An analysis has been conducted to find out whether the management techniques developed in connection with the Apollo project could be used for dealing with such urgent problems of modern society as the crisis of the cities, the increasing environmental pollution, and the steadily growing traffic. Basic concepts and definitions of program and system management are discussed together with details regarding the employment of these concepts in connection with the solution of the problems of the Apollo program. Principles and significance of a systems approach are considered, giving attention to planning, system analysis, system integration, and project management. An application of the methods of project management to the problems of the civil sector is possible if the special characteristics of each particular case are taken into account.

  9. Three-dimensional electron diffraction as a complementary technique to powder X-ray diffraction for phase identification and structure solution of powders

    PubMed Central

    Yun, Yifeng; Zou, Xiaodong; Hovmöller, Sven; Wan, Wei

    2015-01-01

    Phase identification and structure determination are important and widely used techniques in chemistry, physics and materials science. Recently, two methods for automated three-dimensional electron diffraction (ED) data collection, namely automated diffraction tomography (ADT) and rotation electron diffraction (RED), have been developed. Compared with X-ray diffraction (XRD) and two-dimensional zonal ED, three-dimensional ED methods have many advantages in identifying phases and determining unknown structures. Almost complete three-dimensional ED data can be collected using the ADT and RED methods. Since each ED pattern is usually measured off the zone axes by three-dimensional ED methods, dynamic effects are much reduced compared with zonal ED patterns. Data collection is easy and fast, and can start at any arbitrary orientation of the crystal, which facilitates automation. Three-dimensional ED is a powerful technique for structure identification and structure solution from individual nano- or micron-sized particles, while powder X-ray diffraction (PXRD) provides information from all phases present in a sample. ED suffers from dynamic scattering, while PXRD data are kinematic. Three-dimensional ED methods and PXRD are complementary and their combinations are promising for studying multiphase samples and complicated crystal structures. Here, two three-dimensional ED methods, ADT and RED, are described. Examples are given of combinations of three-dimensional ED methods and PXRD for phase identification and structure determination over a large number of different materials, from Ni–Se–O–Cl crystals, zeolites, germanates, metal–organic frameworks and organic compounds to intermetallics with modulated structures. It is shown that three-dimensional ED is now as feasible as X-ray diffraction for phase identification and structure solution, but still needs further development in order to be as accurate as X-ray diffraction. It is expected that three-dimensional ED

  10. Effect of various de-anodizing techniques on the surface stability of non-colored and colored nanoporous AAO films in acidic solution

    NASA Astrophysics Data System (ADS)

    Awad, Ahmed M.; Shehata, Omnia S.; Heakal, Fakiha El-Taib

    2015-12-01

    Anodic aluminum oxide (AAO) is well known as an important nanostructured material, and a useful template in the fabrication of nanostructures. Nanoporous anodic alumina (PAA) with high open porosity was prepared by adopting three de-anodizing regimes following the first anodizing step and preceding the second one. The de-anodizing methods include electrolytic etching (EE) and chemical etching using either phosphoric acid (PE) or sodium hydroxide (HE) solutions. Three of the obtained AAO samples were black colored by electrodeposition of copper nanoparticles in their pores. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques were used to characterize the electrochemical performance of the two sets of the prepared samples. In general, the data obtained in aggressive aerated 0.5 M HCl solution demonstrated dissimilar behavior for the three prepared samples despite that the second anodizing step was the same for all of them. The data indicated that the resistance and thickness of the inner barrier part of nano-PAA film, are the main controlling factors determining its stability. On the other hand, coloring the film decreased its stability due to the galvanic effect. The difference in the electrochemical behavior of the three colored samples was discussed based on the difference in both the pore size and thickness of the outer porous part of PAA film as supported by SEM, TEM and cross-sectional micrographs. These results can thus contribute for better engineering applications of nanoporous AAO.

  11. Simultaneous determination of iodide and iodate in povidone iodine solution by ion chromatography with homemade and exchange capacity controllable columns and column-switching technique.

    PubMed

    Huang, Zhongping; Zhu, Zuoyi; Subhani, Qamar; Yan, Wenwu; Guo, Weiqiang; Zhu, Yan

    2012-08-17

    A simple ion chromatographic method for simultaneous detection of iodide and iodate in a single running was proposed, with columns packed with homemade functionalized polystyrene-divinylbenzene (PS-DVB) resins and column-switching technique. Homemade resins were functionalized with controllable amounts of quaternary ammonium groups. The low-capacity anion-exchange column and high-capacity anion-exchange column were prepared, due to the resins having different exchange capacities. With this method, iodide and iodate in povidone iodine solution were detected simultaneously in a short time with iodide being eluted off first. A series of standard solutions consisting of target anions of various concentrations from 0.01 mg/L to 100 mg/L were analyzed. Each anion exhibited satisfactory linearity, with correlation coefficient r ≥ 0.9990. The detection limits (LODs) for iodide and iodate obtained by injecting 100 μL of sample were 5.66 and 14.83 μg/L (S/N=3), respectively. A spiking study was performed with satisfactory recoveries between 101.2% and 100.6% for iodide and iodate. PMID:22771256

  12. Poly-L-lactide/sodium alginate/chitosan microsphere hybrid scaffolds made with braiding manufacture and adhesion technique: Solution to the incongruence between porosity and compressive strength.

    PubMed

    Lin, Jia-Horng; Chen, Chih-Kuang; Wen, Shih-Peng; Lou, Ching-Wen

    2015-01-01

    Bone scaffolds require a three-dimensional structure, high porosity, interconnected pores, adequate mechanical strengths, and non-toxicity. A high porosity is incongruent with mechanical strengths. Therefore, this study combines a braiding method and microsphere solution to create bone scaffolds with a high porosity and sufficient mechanical strengths. First, poly-L-lactide (PLLA) plied yarns are braided into 5-, 10-, 15-, 20-, and 25-layer hollow braids, and then thermally treated at 165 °C for various durations. Next, sodium alginate (SA) microspheres, cross-linked with CaCl2 solution with various concentrations, are combined with PLLA porous braided bone scaffolds to form PLLA/SA/CS microsphere hybrid scaffolds, which are then observed for surface observation, and tested for porosity, water contact angle, compressive strength, MTT assay, bioactivity, alkaline phosphatase (ALP) assay, cell attachment, and statistical analyses. The test results show that the layer amount of the bone scaffold is proportional to the compressive strength. With the same number of layers, the compressive strength is inversely proportional to the concentration of the CaCl2 solution. The results of surface observation, porosity, and water contact angle tests show that PLLA/SA/CS microsphere hybrid scaffolds possess a high porosity and good hydrophilicity; as a result, the braiding manufacture and the bonding technique effectively solve the confliction between porosity and mechanical strength. The concentration of CaCl2 does not pertain to cell activity and ALP results, exemplified by good cell attachment on bone scaffolds for each specification. PMID:25953547

  13. Growth, structural and optical properties of non-stoichiometric CuIn(S1-xSex)2 thin films deposited by solution growth technique for photovoltaic application

    NASA Astrophysics Data System (ADS)

    Chavhan, S.; Sharma, R.

    2006-04-01

    Polycrystalline thin films of p-CuIn(S1-xSex)2 have been deposited by a solution growth technique. The deposition parameters such as pH, temperature and time have been optimized. In order to achieve uniformity of thin film, triethanolamine (TEA) has been used. As deposited films have been annealed at 450 °C in air for 5 min. The surface morphology, compositional ratio, structural properties have been studied by SEM, EDAX and XRD technique, respectively. It has been found that films have chalcopyrite structure with the lattice parameters a=5.28 Å and c=11.45 Å at composition x=0.5. The grain size of all composition x measured from SEM and XRD is varied in between 450 and 520 nm. The optical transmittance spectra have been recorded in the range 350 1000 nm. The absorption coefficient has been calculated at the absorption edge for each of the composition x and it is in the range of 104 cm-1. The material shows the direct allowed band gap, which varies from 1.07 to 1.44 eV with change in composition (0≤x≤1.0). These parameters are useful for the photovoltaic application.

  14. Growth and optoelectronic characteristic of n-Si/p-CuIn(S 1-xSe x) 2 thin-film solar cell by solution growth technique

    NASA Astrophysics Data System (ADS)

    Chavhan, S.; Sharma, R.

    2006-07-01

    The p-CuIn(S 1-xSe x) 2 (CISS) thin films have been grown on n-Si substrate by solution growth technique. The deposition parameters, such as pH (10.5), deposition time (60 min), deposition temperature (50 °C), and concentration of bath solution (0.1 M) were optimized. Elemental analysis of the p-CuIn(S 1-xSe x) 2 thin film was confirmed by energy-dispersive analysis of X-ray (EDAX). The SEM study of absorber layer shows the uniform morphology of film as well as the continuous smooth deposition onto the n-Si substrates, whose grain size is 130 nm. CuIn(S 1-xSe x) 2 ( x=0.5) reveals (1 1 2) orientation peak and exhibits the chalcopyrite structure with lattice constant a=5.28 Å and c=11.45 Å. The J- V characteristics were measured in dark and light. The device parameters have been calculated for solar cell fabrication, V=411.09 mV, and J=14.55 mA. FF=46.55% and η=4.64% under an illumination of 60 mW/cm 2. The J- V characteristics of the device under dark condition were also studied and the ideality factor was calculated, which is equal to 2.2 for n-Si/p-CuIn(S 0.5Se 0.5) 2 heterojunction thin film.

  15. Photovoltaic effect in BiFeO3/BaTiO3 multilayer structure fabricated by chemical solution deposition technique

    NASA Astrophysics Data System (ADS)

    Sharma, Savita; Tomar, Monika; Kumar, Ashok; Puri, Nitin K.; Gupta, Vinay

    2016-06-01

    Photovoltaic (PV) properties of bismuth ferrite (BFO) and barium titanate (BTO) multilayered ferroelectric BFO/BTO/BFO/BTO thin film structure deposited on Pt/Ti/SiO2/Si substrates using chemical solution deposition technique are presented. X-ray diffraction analysis confirms pure phase polycrystalline nature of deposited perovskite multilayered structures. Simultaneously both distorted rhombohedral (R3c) and tetragonal phases (P4mm) of the respective BFO and BTO components are also well retained. The ferroelectric sandwiched structures grown on fused quartz substrates exhibit high optical transmittance (~70%) with an energy band gap 2.62 eV. Current-voltage characteristics and PV response of multilayered structures is determined in metal-ferroelectric-metal (MFM) capacitor configuration. Considerably low magnitude of dark current density 1.53×10-7 A at applied bias of 5 V establish the resistive nature of semi-transparent multilayered structure. Enhanced PV response with 40 nm thin semitransparent Au as top electrode is observed under solid-state violet laser illumination (λ - 405 nm, 160 mW/cm2). The short circuit current density and open circuit voltage are measured to be 12.65 μA/cm2 and 1.43 V respectively with a high retentivity. The results obtained are highly encouraging for employing artificial multilayered engineering to improve PV characteristics.

  16. Convective solution transport — An improved technique for the growth of big crystals of the superconducting α-FeSe using KCl as solvent

    NASA Astrophysics Data System (ADS)

    Rao, S. M.; Mok, B. H.; Ling, M. C.; Ke, C. T.; Chen, T. K.; Tsai, I.-M.; Lin, Y.-L.; Liu, H. L.; Chen, C. L.; Hsu, F. C.; Huang, T. W.; Wu, T. B.; Wu, M. K.

    2011-12-01

    An improved technique of convective solution transport using KCl as solvent at 840-790 °C (where mass transport takes place across a vertical temperature gradient) is described for the growth of crystals of the recently discovered superconductor α-FeSex (x = 1-0.8). The crystals were annealed in situ at 400-350 °C for 20-30 h to improve the superconducting properties. Hexagonal plate like crystals measuring 5-6 mm across and 0.25-0.5 mm thick were obtained. High resolution transmission electron microscopy (HRTEM) measurements show good crystallinity and the energy dispersive x-ray analysis (EDX) gives a composition very close to the starting powders. The zero resistance temperature of the crystals was found to increase from 6.5 to 9 K as the composition is decreased from x = 0.95 to 0.9 and decrease thereafter. Similar behavior was also observed in the powder x-ray diffraction (XRD) patterns and Raman spectra with the main peak shifting to higher value until 0.9 and decrease thereafter. In addition the XRD patterns show reducing hexagonal phase reflections as x decreases to 0.9. Anisotropic magnetic behavior was observed when the magnetic field is applied parallel and perpendicular to the (101) face.

  17. Comparative study on L-alaninium maleate single crystal grown by Sankaranarayanan-Ramasamy (SR) method and conventional slow evaporation solution technique

    NASA Astrophysics Data System (ADS)

    Charoen-In, Urit; Ramasamy, P.; Manyum, P.

    2010-08-01

    Single crystals of L-alaninium maleate (LAM) were successfully grown by Sankaranarayanan-Ramasamy (SR) method and conventional slow evaporation solution technique, which have the sizes of 32 mm in length, 18 mm in diameter and 18×13×2 mm 3. The grown LAM crystals were subjected to single crystal X-ray diffraction, high resolution X-ray diffraction (HRXRD), chemical etching, dielectric permittivity, dielectric loss, thermo-gravimetric-differential thermal analysis, UV-vis NIR and Vickers microhardness analysis and the results were compared. Single crystal X-ray diffraction confirmed the lattice parameters of the grown LAM crystals. The HRXRD analysis indicated that the crystalline perfection of the SR method grown LAM crystals is quite good without having any internal structural grain boundaries. Chemical etching studies represent the distribution of structural defects in LAM crystal and etch pit density of conventional and SR method grown LAM crystal was calculated. The dielectric permittivity and loss measurement were made as function of temperature in the range 40-140 °C. From thermo-gravimetric-differential thermal analysis of the grown crystal, the thermal stability was found to be up to 158 °C. The range and percentage of optical transmission are represented by recording UV-vis analysis. Mechanical strength of the grown LAM crystals was analyzed by Vickers microhardness test and the hardness of SR method grown LAM crystal is higher than the hardness of the crystal grown by conventional method.

  18. Influence of temperature on the electric, dielectric and AC conductivity properties of nano-crystalline zinc substituted cobalt ferrite synthesized by solution combustion technique

    NASA Astrophysics Data System (ADS)

    Rani, Ritu; Kumar, Gagan; Batoo, Khalid M.; Singh, M.

    2014-06-01

    Cobalt-zinc nanoferrites with formulae Co ZnFeO, where x = 0.0, 0.1, 0.2 and 0.3, have been synthesized by solution combustion technique. The variation of DC resistivity with temperature shows the semiconducting behavior of all nanoferrites. The dielectric properties such as dielectric constant (') and dielectric loss tangent (tan are investigated as a function of temperature and frequency. Dielectric constant and loss tangent are found to be increasing with an increase in temperature while with an increase in frequency both, ' and tan , are found to be decreasing. The dielectric properties have been explained on the basis of space charge polarization according to Maxwell-Wagner's two-layer model and the hopping of charge between Fe and Fe. Further, a very high value of dielectric constant and a low value of tan are the prime achievements of the present work. The AC electrical conductivity ( is studied as a function of temperature as well as frequency and is observed to be increasing with the increase in temperature and frequency.

  19. Pressure and temperature dependence of the elasticity of pyrope-majorite [Py 60Mj 40 and Py 50Mj 50] garnets solid solution measured by ultrasonic interferometry technique

    NASA Astrophysics Data System (ADS)

    Gwanmesia, Gabriel D.; Wang, Liping; Triplett, Richard; Liebermann, Robert C.

    2009-05-01

    Compressional (P) and shear (S) wave velocities have been measured for two synthetic polycrystalline specimens of pyrope-majorite garnets [Py 60Mj 40 and Py 50Mj 50] by ultrasonic interferometry to 8 GPa and 1000 K, in a DIA-type cubic anvil high pressure apparatus (SAM-85) interfaced with synchrotron X-radiation and X-ray imaging. Elastic bulk ( KS) and shear ( G) moduli data obtained at the end of the cooling cycles were fitted to functions of Eulerian strain to third order yielding pressure derivatives of the elastic moduli (∂ KS/∂ P) T = 4.3 (3); (∂ G/∂ P) T = 1.5 (1) for Py 60Mj 40 garnet and (∂ KS/∂ P) T = 4.4 (1); (∂ G/∂ P) T = 1.3 (1) for Py 50Mj 40 garnet. Both (∂ KS/∂ P) T and (∂ G/∂ P) T are identical for the two garnet compositions and are also consistent with Brillouin scattering data for polycrystalline Py 50Mj 50. Moreover, the new pressure derivatives of the elastic moduli are equal within experimental uncertainties to those of end-member pyrope garnet from ultrasonic studies [Gwanmesia, G.D., Zhang. J, Darling, K., Kung, J., Li, B., Wang, L., Neuville, D., Liebermann, R.C., 2006. Elasticity of polycrystalline pyrope (Mg 3Al 2Si 3O 12) to 9 GPa and 1000 °C. Phys. Earth Planet. Inter. 155, 179-190] and from Brillouin spectroscopic studies [Sinogeikin, S.V., Bass, J.D., 2002a. Elasticity of majorite and majorite-pyrope solid solution to high pressure: implications for the transition zone. Geophys. Res. 9(2), 1017], thereby demonstrating that the pressure derivatives of the elastic moduli are independent of the physical acoustics technique employed and unaffected by substitution of Si for Mg and Al within the Py-Mj solid solution in the range (Py 100-Py 50) of the present measurements. Temperature dependence of the elastic obtained from linear regression of entire P- T- K and P- T- G data are (∂ KS/∂ T) P = -14.6 (4) MPa/K; (∂ G/∂ T) P = -9.4 (4) MPa/K for Py 60Mj 40 garnet, and (∂ KS/∂ T) P = -14.6 (4) MPa/K; (

  20. An ion-imprinted amino-functionalized silica gel sorbent prepared by hydrothermal assisted surface imprinting technique for selective removal of cadmium (II) from aqueous solution

    NASA Astrophysics Data System (ADS)

    Fan, Hong-Tao; Li, Jing; Li, Zhan-Chao; Sun, Ting

    2012-02-01

    A new ion-imprinted amino-functionalized silica gel sorbent was synthesized by the hydrothermal-assisted surface imprinting technique using Cd2+ as the template, 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane (AAAPTS) as the functional monomer, and epichlorohydrin as the cross-linking agent (IIP-AAAPTS/SiO2) for the selective removal of Cd2+ from aqueous solution, and was characterized by FTIR, SEM, nitrogen adsorption and the static adsorption-desorption experiment method. The specific surface area of the IIP-AAAPTS/SiO2 sorbents was found to be 149 m2 g-1. The results showed that the maximum static adsorption capacities of IIP-AAAPTS/SiO2 sorbents by hydrothermal heating method and by the conventional heating method were 57.4 and 31.6 mg g-1, respectively. The IIP-AAAPTS/SiO2 sorbents offered a fast kinetics for the adsorption and desorption of Cd(II). The relative selectivity coefficients of IIP-AAAPTS/SiO2 sorbents for Cd2+/Co2+, Cd2+/Ni2+, Cd2+/Zn2+, Cd2+/Pb2+ and Cd2+/Cu2+ were 30.68, 14.02, 3.00, 3.12 and 6.17, respectively. IIP-AAAPTS/SiO2 sorbents had a substantial binding capacity in the range of pH 4-8 and could be used repeatedly. Equilibrium data fitted perfectly with Langmuir isotherm model compared to Freundlich isotherm model. Kinetic studies indicated that adsorption followed a pseudo-second-order model. Negative values of ΔG° indicated spontaneous adsorption and the degree of spontaneity of the reaction increased with increasing temperature. ΔH° of 26.13 kJ mol-1 due to the adsorption of Cd2+ on the IIP-AAAPTS/SiO2 sorbents indicated that the adsorption was endothermic in the experimental temperature range.

  1. Fabrication of organic FETs based on printing techniques and the improvement of FET properties by the insertion of solution-processable buffer layers

    NASA Astrophysics Data System (ADS)

    Itoh, Eiji; Kanamori, Akira

    2016-04-01

    In this study, we developed multilayer deposition and patterning processes that can be used to fabricate all-printed, organic field-effect transistors (OFETs) on the basis of vacuum-free, solution-processable soft-lithography techniques. We have used regioregular poly(3-hexylthiophene) (P3HT) as a soluble p-type polymer semiconductor and (6,6)-phenyl C61 butyric acid methyl ester (PCBM) as a soluble n-type semiconductor, and cross-linked poly(vinyl phenol) (CL-PVP) as a low-temperature (<150 °C)-curable soluble polymer gate insulator. We have compared the electrical properties of OFETs with multiwalled carbon nanotubes (MWCNTs), silver nanoparticles (NPs), and their composites (or multilayers) as printed source-drain (S-D) electrodes in order to fabricate vacuum-free, all-printed OFETs. The P3HT-OFETs with MWCNT S-D electrodes exhibited higher hole mobility and on/off ratios than the devices with Ag NP S-D electrodes owing to better contact at the MWCNT/P3HT interface. On the other hand, Ag/molybdenum oxide (MoO3) S-D electrodes considerably enhanced the hole injection and caused the reduction in the on/off ratio and the difficulty in turning off the devices. The PCBM-OFETs with MWCNT S-D electrodes also exhibited higher electron mobility that is almost comparable to that of P3HT-OFETs and lower threshold voltage, which was considered to be due to the enhanced electron injection at the electrode interface.

  2. Solitary wave solutions for time fractional third order modified KdV equation using two reliable techniques (G‧ / G) -expansion method and improved (G‧ / G) -expansion method

    NASA Astrophysics Data System (ADS)

    Sahoo, S.; Saha Ray, S.

    2016-04-01

    In the present paper, we construct the analytical exact solutions of a nonlinear evolution equation in mathematical physics; namely time fractional modified KdV equation by using (G‧ / G)-expansion method and improved (G‧ / G)-expansion method. As a result, new types of exact analytical solutions are obtained.

  3. Numerical techniques for the solution of the compressible Navier-Stokes equations and implementation of turbulence models. [separated turbulent boundary layer flow problems

    NASA Technical Reports Server (NTRS)

    Baldwin, B. S.; Maccormack, R. W.; Deiwert, G. S.

    1975-01-01

    The time-splitting explicit numerical method of MacCormack is applied to separated turbulent boundary layer flow problems. Modifications of this basic method are developed to counter difficulties associated with complicated geometry and severe numerical resolution requirements of turbulence model equations. The accuracy of solutions is investigated by comparison with exact solutions for several simple cases. Procedures are developed for modifying the basic method to improve the accuracy. Numerical solutions of high-Reynolds-number separated flows over an airfoil and shock-separated flows over a flat plate are obtained. A simple mixing length model of turbulence is used for the transonic flow past an airfoil. A nonorthogonal mesh of arbitrary configuration facilitates the description of the flow field. For the simpler geometry associated with the flat plate, a rectangular mesh is used, and solutions are obtained based on a two-equation differential model of turbulence.

  4. Growth of Uniform Ga{sub 1-x}In{sub x}Sb Bulk Crystals by Self-Solute Feeding Technique

    SciTech Connect

    P.S. Dutta; G. Rajagopalan; R.J. Gutmann; G. Nichols

    2003-08-29

    Compositionally homogeneous, crack-free bulk crystals of Ga{sub 1-x}In{sub x}Sb with x as high as 0.4 has been grown for the first time using a self-solute feeding method. A balance between the growth rate and the spacing between the solute and the growth interface has been found to be crucial in maintaining uniform alloy composition.

  5. Application of a local linearization technique for the solution of a system of stiff differential equations associated with the simulation of a magnetic bearing assembly

    NASA Technical Reports Server (NTRS)

    Kibler, K. S.; Mcdaniel, G. A.

    1981-01-01

    A digital local linearization technique was used to solve a system of stiff differential equations which simulate a magnetic bearing assembly. The results prove the technique to be accurate, stable, and efficient when compared to a general purpose variable order Adams method with a stiff option.

  6. Two new species and a new subgenus of toothed Brachyhypopomus electric knifefishes (Gymnotiformes, Hypopomidae) from the central Amazon and considerations pertaining to the evolution of a monophasic electric organ discharge

    PubMed Central

    Sullivan, John P.; Zuanon, Jansen; Cox Fernandes, Cristina

    2013-01-01

    Abstract We describe two new, closely related species of toothed Brachyhypopomus (Hypopomidae: Gymnotiformes: Teleostei) from the central Amazon basin and create a new subgenus for them. Odontohypopomus, new subgenus of Brachyhypopomus, is diagnosed by (1) small teeth present on premaxillae; (2) medialmost two branchiostegal rays thin with blades oriented more vertically than remaining three rays; (3) background color in life (and to lesser extent in preservation) distinctly yellowish with head and sides peppered with small, widely spaced, very dark brown stellate chromatophores that greatly contrast with light background coloration; (4) a dark blotch or bar of subcutaneous pigment below the eye; (5) electric organ discharge waveform of very long duration (head-positive phase approx. 2 milliseconds or longer, head-negative phase shorter or absent) and slow pulse repetition rate (3–16 Hz). The type species of the new subgenus, Brachyhypopomus (Odontohypopomus) walteri sp. n., is diagnosed by the following additional character states: (1) subcutaneous dark pigment at base of orbit particularly prominent, (2) body semi-translucent and nearly bright yellow background coloration in life, (3) a biphasic electric organ discharge (EOD) waveform of very long duration (between 3.5 and 4 milliseconds at 25° C) with head-positive first phase significantly longer than second head-negative phase in both sexes. Brachyhypopomus (Odontohypopomus) bennetti sp. n. is diagnosed by two character states in addition to those used to diagnose the subgenus Odontohypopomus: (1) a deep electric organ, visible as large semi-transparent area, occupying approximately 14–17% body depth directly posterior to the abdominal cavity in combination with a short, but deep, caudal filament, and (2) a monophasic, head-positive EOD waveform, approximately 2.1 milliseconds in duration in both sexes. These are the only described rhamphichthyoid gymnotiforms with oral teeth, and Brachyhypopomus bennetti

  7. Review of some adaptive node-movement techniques in finite-element and finite-difference solutions of partial differential equations

    NASA Astrophysics Data System (ADS)

    Hawken, D. F.; Gottlieb, J. J.; Hansen, J. S.

    1991-08-01

    Results are presented from a search of the literature on adaptive numerical methods for the solution of PDEs, using node-movements to yield low truncation-solution error levels while minimizing the number of nodes required in the calculation. The applications in question encompass nonstationary flow problems containing moving regions of rapid flow-variable change, amid regions of comparatively smooth variation. Flows involving shock waves, contact surfaces, slipstreams, boundary layers, and phase-change interfaces, are shown to be modeled with both great precision and economy of execution, if the nodes are moved so that they are concentrated in the rapid flow-variable change regions.

  8. A Randomized, Evaluator-Blinded, Split-Face Comparison Study of the Efficacy and Safety of a Novel Mannitol Containing Monophasic Hyaluronic Acid Dermal Filler for the Treatment of Moderate to Severe Nasolabial Folds

    PubMed Central

    Kim, Byung Wook; Moon, Ik Jun; Yun, Woo Jin; Chung, Bo Young; Kim, Sang Duck

    2016-01-01

    Background Mannitol containing monophasic filler with higher crosslinking has not been well studied for moderate and severe nasolabial fold (NLF) correction. Objective To compare the efficacy and safety of a novel mannitol containing hyaluronic acid (HA) filler (HA-G) with biphasic HA filler (HA-P) for moderate and severe NLF correction. Methods Thirteen subjects with symmetric moderate to severe NLF received HA-G (in one NLF) and HA-P (in other NLF) and were evaluated for 24 weeks. Results At both 12 and 24 weeks, the mean improvement in Genzyme 6-point grading scale from baseline was significantly greater in the side of face that was treated with HA-G than HA-P (1.96±0.91 vs. 1.54±0.73 at week 12; p=0.044, 1.88±0.78 vs. 1.3±0.79 at week 24; p=0.027, respectively). At 12 weeks, the mean Global Aesthetic Improvement Scale score was 2.92±0.93 for HA-G and 2.31±0.95 for HA-P (p=0.008). Both fillers were well tolerated. Conclusion The HA filler HA-G provides better efficacy and similar local tolerability compared with HA-P in 6 months following treatment for moderate and severe NLF. PMID:27274627

  9. Efficacy and tolerability of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol in a 24/4 regimen, in comparison to an oral contraceptive containing ethinylestradiol and drospirenone in a 21/7 regimen

    PubMed Central

    Mansour, Diana; Verhoeven, Carole; Sommer, Werner; Weisberg, Edith; Taneepanichskul, Surasak; Melis, Gian Benedetto; Sundström-Poromaa, Inger; Korver, Tjeerd

    2011-01-01

    Objectives The primary objective was to assess the efficacy, cycle control and tolerability of a monophasic combined oral contraceptive (COC) containing nomegestrol acetate (NOMAC) and 17β-oestradiol (E2). Effects on acne were evaluated as a secondary objective. Results were compared to those of a COC containing drospirenone (DRSP) and ethinylestradiol (EE). Methods Women (aged 18-50 years) were randomised to receive NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n = 1591) or DRSP/EE (3 mg/30 μg) in a 21/7-day regimen (n = 535) for 13 cycles. Results Estimated Pearl Indices for NOMAC/E2 and DRSP/EE were 0.38 and 0.81 in women aged ≤ 35 years and 0.31 and 0.66 for all women (18–50 years), respectively. Scheduled withdrawal bleedings were shorter and lighter among users of NOMAC/E2 and were sometimes absent altogether. Intracyclic bleeding/spotting was infrequent in both groups, and decreased over time. Type and frequency of adverse events were similar to those typically reported for COCs. Conclusions These data show that NOMAC/E2 provides high contraceptive efficacy with acceptable cycle control as well as an overall adverse event profile similar to that of DRSP/EE. PMID:21995590

  10. Bonded functional esthetic prototype: an alternative pre-treatment mock-up technique and cost-effective medium-term esthetic solution.

    PubMed

    McLaren, Edward A

    2013-09-01

    As the economy has receded in recent years, many patients have been inclined to reject dental treatment beyond what they feel is the minimal amount necessary. Increasingly, there has been reluctance to take on the expense of full-mouth restorations and time-consuming procedures. Consequently, clinicians can benefit from innovative, conservative, interim solutions that enable them to provide segment treatment with long-term stability and esthetics, with lower initial cost. The bonded functional esthetic prototype (BFEP) allows fabrication of up to 14 teeth from composite in 1 hour, providing either a pre-treatment restoration or a long-term provisional solution until further treatment can be completed. As demonstrated herein, the BFEP enables superb function, stability, and esthetics in the interim while dispersing the cost of definitive treatment over time. PMID:24564612

  11. Task reports on developing techniques for scattering by 3D composite structures and to generate new solutions in diffraction theory using higher order boundary conditions

    NASA Technical Reports Server (NTRS)

    Volakis, John L.

    1991-01-01

    There are two tasks described in this report. First, an extension of a two dimensional formulation is presented for a three dimensional body of revolution. A Fourier series expansion of the vector electric and magnetic fields is employed to reduce the dimensionality of the system, and an exact boundary condition is employed to terminate the mesh. The mesh termination boundary is chosen such that it leads to convolutional boundary operators for low O(n) memory demand. Second, rigorous uniform geometrical theory of diffraction (UTD) diffraction coefficients are presented for a coated convex cylinder simulated with generalized impedance boundary conditions. Ray solutions are obtained which remain valid in the transition region and reduce uniformly those in the deep lit and shadow regions. A uniform asymptotic solution is also presented for observations in the close vicinity of the cylinder.

  12. Laser-induced breakdown spectroscopy technique for quantitative analysis of aqueous solution using matrix conversion based on plant fiber spunlaced nonwovens.

    PubMed

    Chen, Chenghan; Niu, Guanghui; Shi, Qi; Lin, Qingyu; Duan, Yixiang

    2015-10-01

    In the present work, laser-induced breakdown spectroscopy (LIBS) was applied to detect concentrations of chromium and nickel in aqueous solution in the form of matrix conversion using plant fiber spunlaced nonwovens as a solid-phase support, which can effectively avoid the inherent difficulties such as splashing, a quenching effect, and a shorter plasma lifetime during the liquid LIBS analysis. Drops of the sample solution were transferred to the plant fiber spunlaced nonwovens surface and uniformly diffused from the center to the whole area of the substrate. Owing to good hydrophilicity, the plant fiber spunlaced nonwovens can hold more of the liquid sample, and the surface of this material never wrinkles after being dried in a drying oven, which can effectively reduce the deviation during the LIBS analysis. In addition, the plant fiber spunlaced nonwovens used in the present work are relatively convenient and low cost. Also, the procedure of analysis was simple and fast, which are the unique features of LIBS technology. Therefore, this method has potential applications for practical and in situ analyses. To achieve sensitive elemental detection, the optimal delay time in this experiment was investigated. Under the optimized condition, the limits of detection for Cr and Ni are 0.7 and 5.7  μg·mL(-1), respectively. The results obtained in the present study show that the matrix conversion method is a feasible option for analyzing heavy metals in aqueous solutions by LIBS technology. PMID:26479603

  13. Radiative transfer equation for predicting light propagation in biological media: comparison of a modified finite volume method, the Monte Carlo technique, and an exact analytical solution.

    PubMed

    Asllanaj, Fatmir; Contassot-Vivier, Sylvain; Liemert, André; Kienle, Alwin

    2014-01-01

    We examine the accuracy of a modified finite volume method compared to analytical and Monte Carlo solutions for solving the radiative transfer equation. The model is used for predicting light propagation within a two-dimensional absorbing and highly forward-scattering medium such as biological tissue subjected to a collimated light beam. Numerical simulations for the spatially resolved reflectance and transmittance are presented considering refractive index mismatch with Fresnel reflection at the interface, homogeneous and two-layered media. Time-dependent as well as steady-state cases are considered. In the steady state, it is found that the modified finite volume method is in good agreement with the other two methods. The relative differences between the solutions are found to decrease with spatial mesh refinement applied for the modified finite volume method obtaining <2.4%. In the time domain, the fourth-order Runge-Kutta method is used for the time semi-discretization of the radiative transfer equation. An agreement among the modified finite volume method, Runge-Kutta method, and Monte Carlo solutions are shown, but with relative differences higher than in the steady state. PMID:24390371

  14. Solutions for implementing time-of-flight techniques in low-angle neutron scattering, as realized on the Low-Q Diffractometer at Los Alamos

    SciTech Connect

    Hjelm, R.P. Jr.; Seeger, P.A.

    1992-12-01

    The implementation of small-angle (Low-momentum transfer) neutron scattering at pulsed spallation sources, using time of flight methods, has meant the introduction of some new ideas in instrument design, data acquisition, data reduction and computer management of the experiment and the data. Here we recount some of the salient aspects of solutions for implementing time of fight small-angle neutron scattering instruments at pulsed sources, as realized on the Low-Q Diffractometer, LQD, at Los Alamos. We consider, fortlier, some of the problems that are yet to be solved, and take a short excursion into the future of SANS instrumentation at pulsed sources.

  15. Solutions for implementing time-of-flight techniques in low-angle neutron scattering, as realized on the Low-Q Diffractometer at Los Alamos

    SciTech Connect

    Hjelm, R.P. Jr.; Seeger, P.A.

    1992-01-01

    The implementation of small-angle (Low-momentum transfer) neutron scattering at pulsed spallation sources, using time of flight methods, has meant the introduction of some new ideas in instrument design, data acquisition, data reduction and computer management of the experiment and the data. Here we recount some of the salient aspects of solutions for implementing time of fight small-angle neutron scattering instruments at pulsed sources, as realized on the Low-Q Diffractometer, LQD, at Los Alamos. We consider, fortlier, some of the problems that are yet to be solved, and take a short excursion into the future of SANS instrumentation at pulsed sources.

  16. Miscibility, Crystallization, and Rheological Behavior of Solution Casting Poly(3-hydroxybutyrate)/poly(ethylene succinate) Blends Probed by Differential Scanning Calorimetry, Rheology, and Optical Microscope Techniques

    NASA Astrophysics Data System (ADS)

    Sun, Wei-hua; Qiao, Xiao-ping; Cao, Qi-kun; Liu, Jie-ping

    2010-02-01

    The miscibility and crystallization of solution casting biodegradable poly(3-hydroxybutyrate)/poly(ethylene succinate) (PHB/PES) blends was investigated by differential scanning calorimetry, rheology, and optical microscopy. The blends showed two glass transition temperatures and a depression of melting temperature of PHB with compositions in phase diagram, which indicated that the blend was partially miscible. The morphology observation supported this result. It was found that the PHB and PES can crystallize simultaneously or upon stepwise depending on the crystallization temperatures and compositions. The spherulite growth rate of PHB increased with increasing of PES content. The influence of compositions on the spherulitic growth rate for the partially miscible polymer blends was discussed.

  17. The influence of flotation solution, sample dilution and the choice of McMaster slide area (volume) on the reliability of the McMaster technique in estimating the faecal egg counts of gastrointestinal strongyles and Dicrocoelium dendriticum in sheep.

    PubMed

    Cringoli, G; Rinaldi, L; Veneziano, V; Capelli, G; Scala, A

    2004-08-13

    The present study was aimed to evaluate the influence of flotation solution, sample dilution, and the choice of McMaster slide area (volume) on the reliability of the McMaster technique in estimating the faecal egg counts of gastrointestinal (GI) strongyles and Dicrocoelium dendriticum in a composite sample of faeces from naturally infected sheep. Fourteen flotation solutions having densities between 1.200 and 1.450, and six sample dilutions, 1:10, 1:15, 1:20, 1:30, 1:40 and 1:50 were used. Each of the six dilutions was divided into 70 aliquots in order to have five replicates of each of the 14 flotation solutions at each of the six dilutions. For each McMaster slide, the GI strongyle and D. dendriticum egg counts were performed under one grid (McM 0.15 ml), two grids (McM 0.3 ml), one chamber (McM 0.5 ml), and both chambers (McM 1.0 ml). Mean eggs per gram (EPG) of faeces of GI strongyles and D. dendriticum were calculated and statistical analyses were performed on the resulting data. The type of flotation solution used significantly influenced the EPG in the GI strongyles and in the D. dendriticum egg counts. All the sucrose-based solutions at density between 1.200 and 1.350 floated more GI strongyle eggs than the others. With respect to D. dendriticum, only six solutions were capable of floating eggs and the potassium iodomercurate solution (density 1.440) floated more eggs than the others. The reliability of the McMaster technique regarding sample dilution was high for both GI strongyle and D. dendriticum EPG at 1:10 and 1:15, and then progressively decreased with increasing dilution. The reliability of the McMaster technique regarding the choice of the McMaster slide area (volume) was high for both GI strongyle and D. dendriticum EPG at the McMaster slide area (volume) of 1.0 ml, i.e. the total area of the McMaster slide. The EPG counts resulting from choosing any of the other three McMaster slide areas (volumes), i.e. McM 0.15 ml, McM 0.3 ml, or McM 0.5 ml

  18. Task reports on developing techniques for scattering by 3D composite structures and to generate new solutions in diffraction theory using higher order boundary conditions

    NASA Technical Reports Server (NTRS)

    Volakis, John L.

    1990-01-01

    There are two tasks described in this report. First, an extension of a two dimensional formulation is presented for a three dimensional body of revolution. With the introduction of a Fourier expansion of the vector electric and magnetic fields, a coupled two dimensional system is generated and solved via the finite element method. An exact boundary condition is employed to terminate the mesh and the fast fourier transformation is used to evaluate the boundary integrals for low O(n) memory demand when an iterative solution algorithm is used. Second, the diffraction by a material discontinuity in a thick dielectric/ferrite layer is considered by modeling the layer as a distributed current sheet obeying generalized sheet transition conditions (GSTC's).

  19. Dynamics of Spontaneous Peptidization of l-, d- and dl-Serine in an Abiotic Solution as Investigated with Use of TLC-Densitometry and the Auxiliary Chromatographic Techniques.

    PubMed

    Godziek, Agnieszka; Maciejowska, Anna; Sajewicz, Mieczysław; Kowalska, Teresa

    2016-08-01

    From our earlier investigations, it comes out that proteinogenic amino acids can undergo spontaneous oscillatory reactions of chiral inversion and peptidization. l-Serine (l-Ser) is an important proteinogenic amino acid with many vital functions in human and mammalian organisms, e.g., it is responsible for good condition of the nervous cell membranes. It undergoes spontaneous oscillatory processes of chiral inversion and peptidization, and the goal of this study was to compare the dynamics of its peptidization with that of d-Ser and dl-Ser (racemate). The main analytical technique used in our experiment was TLC-densitometry, and the auxiliary chromatographic techniques were HPLC-evaporative light scattering detector and LC-MS. The results obtained witness to the differences in peptidization dynamics of the two Ser enantiomers (l and d) and of the racemic mixture thereof (dl). It was shown that dl-Ser characterizes with the higher, and l- and d-Ser with the lower peptidization yields. PMID:26980722

  20. Synthesis and Characterization of Ba(Zr{sub x}Ti{sub 1-x})O{sub 3} Solid Solutions Using Impedance Spectroscopic Techniques

    SciTech Connect

    Bajpai, P. K.; Mohan, C. R. K.

    2011-11-22

    Technologically important solid solutions of Ba(Zr{sub x}Ti{sub 1-x})O{sub 3} are synthesized using conventional solid state route. Relatively dense and single phase ceramics are confirmed using X-ray diffraction. Homogeneous and micron size grain growth is characterized using SEM. Impedance spectroscopy is used to study the electrical properties of ceramics. Broad and diffuse impedance loss peak is observed above 250 deg. C, which shifts towards higher frequency with increase in temperature. The distribution of relaxation frequency may be associated with the B-site cationic disorder due to the random distribution of (Zr{sup 4+}/Ti{sup +4}) having different ionic radii. Impedance relaxation obeys the Arrhenius relation with activation energy, E{tau} is 0.31 eV and 0.48 eV for BZT compositions with x = 0.10 and 0.15 respectively. Equivalent circuit representation using two RC element coupled in parallel is used to analyse the impedance response.

  1. Monitoring and modeling of water flow and solute transport in the soil-plant-atmosphere system of poplar trees to evaluate the effectiveness of phytoremediation techniques.

    NASA Astrophysics Data System (ADS)

    Palladino, Mario; Di Fiore, Paola; Speranza, Giuseppe; Sica, Benedetto; Romano, Nunzio

    2015-04-01

    This work is part of a series of studies being carried out within the EU-Life+ project ECOREMED (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS). The project refers to Litorale Domitio-Agro Aversano that has been identified as National Interest Priority Site (NIPS) and includes some polluted agricultural land belonging to more than 61 municipalities in the Naples and Caserta provinces of the Campania Region. The major aim of the project is to define an operating protocol for agriculture-based bioremediation of contaminated agricultural soils, also including the use of plant extracting pollutants to be used as biomasses for renewable energy production. This contribution specifically address the question of evaluating the effectiveness of phytoremediation actions selected by the project in the pilot area of Trentola-Ducenta and will provide some preliminary results of monitoring and modeling activities. A physical and hydraulic characterization has been carried out in this area where poplar trees were planted. Monitoring of water flow, root water uptake and solute transport in the soil-plant-atmosphere is under way with reference to two trees using capacitance soil moisture and matric potential sensors located at three different soil depths, whereas plant water status and evapotranspiration fluxes are indirectly estimated using fast-responding stem dendrometers.

  2. Rapid adsorption of toxic Pb(II) ions from aqueous solution using multiwall carbon nanotubes synthesized by microwave chemical vapor deposition technique.

    PubMed

    Mubarak, Nabisab Mujawar; Sahu, Jaya Narayan; Abdullah, Ezzat Chan; Jayakumar, Natesan Subramanian

    2016-07-01

    Multiwall carbon nanotubes (MWCNTs) were synthesized using a tubular microwave chemical vapor deposition technique, using acetylene and hydrogen as the precursor gases and ferrocene as catalyst. The novel MWCNT samples were tested for their performance in terms of Pb(II) binding. The synthesized MWCNT samples were characterized using Fourier Transform Infrared (FT-IR), Brunauer, Emmett and Teller (BET), Field Emission Scanning Electron Microscopy (FESEM) analysis, and the adsorption of Pb(II) was studied as a function of pH, initial Pb(II) concentration, MWCNT dosage, agitation speed, and adsorption time, and process parameters were optimized. The adsorption data followed both Freundlich and Langmuir isotherms. On the basis of the Langmuir model, Qmax was calculated to be 104.2mg/g for the microwave-synthesized MWCNTs. In order to investigate the dynamic behavior of MWCNTs as an adsorbent, the kinetic data were modeled using pseudo first-order and pseudo second-order equations. Different thermodynamic parameters, viz., ∆H(0), ∆S(0) and ∆G(0) were evaluated and it was found that the adsorption was feasible, spontaneous and endothermic in nature. The statistical analysis revealed that the optimum conditions for the highest removal (99.9%) of Pb(II) are at pH5, MWCNT dosage 0.1g, agitation speed 160r/min and time of 22.5min with the initial concentration of 10mg/L. Our results proved that microwave-synthesized MWCNTs can be used as an effective Pb(II) adsorbent due to their high adsorption capacity as well as the short adsorption time needed to achieve equilibrium. PMID:27372128

  3. The oxidation of methanol and 2-propanol by potassium peroxodisulphate in aqueous solution: Free-radical chain mechanisms elucidated by radiation-chemical techniques

    NASA Astrophysics Data System (ADS)

    Schuchmann, Heinz-Peter; von Sonntag, Clemens

    The γ-radiolysis of methanol or 2-propanol in the presence of potassium peroxodisulphate has been studied in aqueous solution. These chain reactions have been followed by product analysis at various reactant concentrations. A curve-fitting procedure has been applied in order to extract mechanistic and kinetic information from product yield data. In these alcohols, the reaction chain consists mainly of reactions (10), (11) and (3), (4), respectively. SO -4˙+ CH3OH→ .CH2OH+H ++ SO2-4k=8×10 6dm 3mol -1s -1 (10) .CH2OH+ S2O2-8→ CH2O+ SO-4˙+ H++ SO2-4k=7±2×10 4dm 3mol -1s -1 (11) SO-4˙+( CH3) 2CHOH→ .C( CH3) 2OH+ H++ SO2-4k=9×10 7dm 3mol -1s -1 (3) .C( CH3) 2OH+ S2O2-8→( CH3) 2CO+ SO-4˙+ H++ SO2-4k=9±1×10 5dm 3mol -1s -1. (4) The explanation of the data requires inclusion in the mechanisms of the reaction of SO -4 with S 2O 2-8 which leads to the formation of a species (possibly S 2O -48, reaction 14) which in its behaviour toward the substrate resembles, but is less reactive than, the SO -4 (reactions 15 and 25). This mechanistic complication becomes apparent only at low [alcohol]/[S 2O 2-8] ratios. SO-4˙+ S2O2-8→ SO2-4+ S2O-4˙k=1×10 6dm 3mol -1s -1 (14) S2O-4˙+ CH3OH→ S2O2-8+ CH2OH+ H+k=2×10 4dm 3mol -1s -1 (15) S2O-4˙8+( CH3) 2CHOH→ S2O2-8+ .C( CH3) 2OH+ H+3×10 4⩽k⩽1×10 5dm 3mol -1s -1. (25) Further in the 2-propanol system, the inclusion of the bimolecular transformation of the isopropanol β-radical formed in reaction (5) into the α-radical (reaction 28) is necessary. SO-4˙+( CH3) 2CHOH→ .CH2CH( CH3) OH+ H++ SO2-4k=3±2×10 5dm 3mol -1s -1 (5) .CH 2CH(CH 3)OH+(CH 3) 2CHOH→(CH 3) 2CHOH+ .C(CH 3) 2OH k=7±3×10 2dm 3mol -1s -1. (28)

  4. Synthesis, magnetic and dielectric characterization of nanocrystalline solid solutions of In{sub 2−x}Ni{sub x}O{sub 3} (x = 0.05, 0.10 and 0.15)

    SciTech Connect

    Ahmad, Tokeer; Khatoon, Sarvari; Coolahan, Kelsey

    2013-09-01

    Graphical abstract: Monophasic and crystalline In{sub 2−x}Ni{sub x}O{sub 3} nanoparticles of size 8–15 nm have been synthesized solvothermally and showed red shift in energy band gap which decreases on increasing Ni{sup 2+} concentration in In{sub 2}O{sub 3} host lattice. - Highlights: • Monophasic Ni-doped In{sub 2}O{sub 3} nanoparticles by solvothermal method for first time. • Plausible reaction mechanism using thermogravimetric analysis. • High surface area with small particle size obtained. • Solid solutions exhibit paramagnetism with very weak antiferromagnetic interactions. - Abstract: In{sub 2−x}Ni{sub x}O{sub 3} (x = 0.05, 0.10 and 0.15) nanoparticles were successfully synthesized by solvothermal method by the thermal decomposition of oxalate precursor at 450 °C for the first time. X-ray diffraction studies showed the formation of highly crystalline and monophasic cubic structure of In{sub 2}O{sub 3} which is attributed to the formation of solid solution. These nanoparticles show good optical transmittance in the visible region. Optical measurements showed an energy band gap which decreases with increasing Ni concentration. The grain size decreases from 15 nm to 8 nm and surface area increases from 90 to 254 m{sup 2} g{sup −1} on increasing the Ni concentration. High dielectric constant and dielectric loss has been obtained which indicates the conducting nature of these solid solutions. Magnetic measurements showed that the samples are strong paramagnetic in nature with very weak antiferromagnetic interactions. No evidence of ferromagnetism is observed for these solid solutions at room temperature.

  5. Horizontal Acquisition of a Multidrug-Resistance Module (R-type ASSuT) Is Responsible for the Monophasic Phenotype in a Widespread Clone of Salmonella Serovar 4,[5],12:i:-

    PubMed Central

    García, Patricia; Malorny, Burkhard; Rodicio, M. Rosario; Stephan, Roger; Hächler, Herbert; Guerra, Beatriz; Lucarelli, Claudia

    2016-01-01

    Salmonella enterica serovar 4,[5],12:i:- is a monophasic variant of S. Typhimurium incapable of expressing the second-phase flagellar antigen (fljAB operon), and it is recognized to be one of the most prevalent serovars causing human infections. A clonal lineage characterized by phage type DT193, PulseNet PFGE profile STYMXB.0131 and multidrug resistance to ampicillin, streptomycin, sulphonamides and tetracycline (R-type ASSuT) is commonly circulating in Europe. In this study we determined the deletions affecting the fljAB operon and the resistance region responsible for the R-type ASSuT in a strain of Salmonella enterica serovar 4,5,12:i:- DT193/STYMXB.0131, through an approach based on PCRs and Southern blot hybridization of genomic DNA. Using a set of nine specific PCRs, the prevalence of the resistance region was assessed in a collection of 144 S. enterica serovar 4,[5],12:i:-/ASSuT/STYMXB.0131 strains isolated from Germany, Switzerland and Italy. A 28 kb-region is embedded between the loci STM2759 and iroB, replacing the DNA located in between, including the fljAB operon. It encompasses the genes blaTEM−1, strA-strB, sul2 and tet(B) responsible for the R-type ASSuT together with genes involved in plasmid replication and orfs of unknown function characteristically located on IncH1 plasmids. Its location and internal structure is fairly conserved in S. enterica serovar 4,[5],12:i:-/ASSuT/STYMXB.0131 strains regardless of the isolation source or country. Hence, in the S. enterica serovar 4,[5],12:i:-/ASSuT/STYMXB.0131 clonal lineage widespread in Germany, Switzerland and Italy, a resistance region derived from IncH1 plasmids has replaced the chromosomal region encoding the second flagellar phase and is an example of the stabilization of new plasmid-derived genetic material due to integration into the bacterial chromosome. PMID:27242707

  6. Horizontal Acquisition of a Multidrug-Resistance Module (R-type ASSuT) Is Responsible for the Monophasic Phenotype in a Widespread Clone of Salmonella Serovar 4,[5],12:i:.

    PubMed

    García, Patricia; Malorny, Burkhard; Rodicio, M Rosario; Stephan, Roger; Hächler, Herbert; Guerra, Beatriz; Lucarelli, Claudia

    2016-01-01

    Salmonella enterica serovar 4,[5],12:i:- is a monophasic variant of S. Typhimurium incapable of expressing the second-phase flagellar antigen (fljAB operon), and it is recognized to be one of the most prevalent serovars causing human infections. A clonal lineage characterized by phage type DT193, PulseNet PFGE profile STYMXB.0131 and multidrug resistance to ampicillin, streptomycin, sulphonamides and tetracycline (R-type ASSuT) is commonly circulating in Europe. In this study we determined the deletions affecting the fljAB operon and the resistance region responsible for the R-type ASSuT in a strain of Salmonella enterica serovar 4,5,12:i:- DT193/STYMXB.0131, through an approach based on PCRs and Southern blot hybridization of genomic DNA. Using a set of nine specific PCRs, the prevalence of the resistance region was assessed in a collection of 144 S. enterica serovar 4,[5],12:i:-/ASSuT/STYMXB.0131 strains isolated from Germany, Switzerland and Italy. A 28 kb-region is embedded between the loci STM2759 and iroB, replacing the DNA located in between, including the fljAB operon. It encompasses the genes bla TEM-1, strA-strB, sul2 and tet(B) responsible for the R-type ASSuT together with genes involved in plasmid replication and orfs of unknown function characteristically located on IncH1 plasmids. Its location and internal structure is fairly conserved in S. enterica serovar 4,[5],12:i:-/ASSuT/STYMXB.0131 strains regardless of the isolation source or country. Hence, in the S. enterica serovar 4,[5],12:i:-/ASSuT/STYMXB.0131 clonal lineage widespread in Germany, Switzerland and Italy, a resistance region derived from IncH1 plasmids has replaced the chromosomal region encoding the second flagellar phase and is an example of the stabilization of new plasmid-derived genetic material due to integration into the bacterial chromosome. PMID:27242707

  7. Effect of swift heavy ion irradiation on the physical properties of CuIn(S 0.4Se 0.6) 2 alloy thin films prepared by solution growth technique

    NASA Astrophysics Data System (ADS)

    Chavhan, S. D.; Deshpande, N. G.; Gudage, Y. G.; Ghosh, A.; Ahire, R. R.; Borse, S. V.; Khairnar, R. S.; Jadhav, K. M.; Singh, F.; Sharma, Ramphal

    2008-06-01

    Alloy thin films of CuIn(S 0.4Se 0.6) 2 material were deposited using the solution growth technique. The various deposition parameters such as pH of solution, time, concentration of ions and temperature have been optimized for the device grade thin films. The as-deposited films were annealed in a rapid thermal annealing (RTA) system at 450 °C in air for 5 min and subjected to high-energy Ag ion irradiations. Ag ion irradiation has been performed with an energy of 100 MeV at a fluency of 5×10 12 ions/cm 2 on the thin film. The changes in optical and electrical properties that occurred before and after post-deposition treatments in CuIn(S 0.4Se 0.6) 2 thin films were studied using X-ray diffraction (XRD) and AFM; increase in crystallinity was observed after annealing and irradiation. In addition, structural damages were observed in irradiated thin films. After annealing and irradiation, the surface roughness was seen to be increased. Decrease in resistivity was observed, which is consistent with the optical energy band gap. The results are explained by considering the high energy deposited due to the electronic energy loss upon irradiation, which modified the properties of the material.

  8. Gastroenteric tube feeding: Techniques, problems and solutions

    PubMed Central

    Blumenstein, Irina; Shastri, Yogesh M; Stein, Jürgen

    2014-01-01

    Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake, chronic neurological or mechanical dysphagia or gut dysfunction, and patients who are critically ill. However, despite the benefits and widespread use of enteral tube feeding, some patients experience complications. This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding, together with associated complications and special aspects. We conducted an extensive literature search on PubMed, Embase and Medline using index terms relating to enteral access, enteral feeding/nutrition, tube feeding, percutaneous endoscopic gastrostomy/jejunostomy, endoscopic nasoenteric tube, nasogastric tube, and refeeding syndrome. The literature showed common routes of enteral access to include nasoenteral tube, gastrostomy and jejunostomy, while complications fall into four major categories: mechanical, e.g., tube blockage or removal; gastrointestinal, e.g., diarrhea; infectious e.g., aspiration pneumonia, tube site infection; and metabolic, e.g., refeeding syndrome, hyperglycemia. Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route, gastrointestinal complications are without doubt the most common. Complications associated with enteral tube feeding can be reduced by careful observance of guidelines, including those related to food composition, administration rate, portion size, food temperature and patient supervision. PMID:25024606

  9. Structure and properties of Bi(Zn0.5Ti0.5)O3- Pb(Zr(1-x)Ti(x))O3 ferroelectric single crystals grown by a top-seeded solution growth technique.

    PubMed

    Wang, Bixia; Wu, Xiaoqing; Ren, Wei; Ye, Zuo-Guang

    2015-06-01

    Bi(Zn0.5Ti0.5)O3 (BZT)-modified Pb(Zr(1-x)Ti(x))O3 (PZT) single crystals have been grown using a top-seeded solution growth technique and characterized by various methods. The crystal structure is found to be rhombohedral by means of X-ray powder diffraction. The composition and homogeneity of the as-grown single crystals are studied by laser ablation inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy. The domain structure of a (001)(cub) platelet is investigated by polarized light microscopy (PLM), which confirms the rhombohedral symmetry. The paraelectric-to-ferroelectric phase transition temperature T(C) is found to be 313°C with the absence of rhombohedral-tetragonal phase transition. The ferroelectric properties of the ternary crystals are enhanced by the BZT substitution with a remanent polarization of 28 μC/cm(2) and a coercive field E(C) of 22.1 kV/cm. PMID:26067036

  10. Electromarking solution

    DOEpatents

    Bullock, Jonathan S.; Harper, William L.; Peck, Charles G.

    1976-06-22

    This invention is directed to an aqueous halogen-free electromarking solution which possesses the capacity for marking a broad spectrum of metals and alloys selected from different classes. The aqueous solution comprises basically the nitrate salt of an amphoteric metal, a chelating agent, and a corrosion-inhibiting agent.

  11. Problem Solving Techniques Seminar.

    ERIC Educational Resources Information Center

    Massachusetts Career Development Inst., Springfield.

    This booklet is one of six texts from a workplace literacy curriculum designed to assist learners in facing the increased demands of the workplace. Six problem-solving techniques are developed in the booklet to assist individuals and groups in making better decisions: problem identification, data gathering, data analysis, solution analysis,…

  12. Improving the dissolution rate of poorly water soluble drug by solid dispersion and solid solution: pros and cons.

    PubMed

    Chokshi, Rina J; Zia, Hossein; Sandhu, Harpreet K; Shah, Navnit H; Malick, Waseem A

    2007-01-01

    The solid dispersions with poloxamer 188 (P188) and solid solutions with polyvinylpyrrolidone K30 (PVPK30) were evaluated and compared in an effort to improve aqueous solubility and bioavailability of a model hydrophobic drug. All preparations were characterized by differential scanning calorimetry, powder X-ray diffraction, intrinsic dissolution rates, and contact angle measurements. Accelerated stability studies also were conducted to determine the effects of aging on the stability of various formulations. The selected solid dispersion and solid solution formulations were further evaluated in beagle dogs for in vivo testing. Solid dispersions were characterized to show that the drug retains its crystallinity and forms a two-phase system. Solid solutions were characterized to be an amorphous monophasic system with transition of crystalline drug to amorphous state. The evaluation of the intrinsic dissolution rates of various preparations indicated that the solid solutions have higher initial dissolution rates compared with solid dispersions. However, after storage at accelerated conditions, the dissolution rates of solid solutions were lower due to partial reversion to crystalline form. The drug in solid dispersion showed better bioavailability in comparison to solid solution. Therefore, considering physical stability and in vivo study results, the solid dispersion was the most suitable choice to improve dissolution rates and hence the bioavailability of the poorly water soluble drug. PMID:17107929

  13. Polymer solutions

    SciTech Connect

    Krawczyk, Gerhard Erich; Miller, Kevin Michael

    2011-07-26

    There is provided a method of making a polymer solution comprising polymerizing one or more monomer in a solvent, wherein said monomer comprises one or more ethylenically unsaturated monomer that is a multi-functional Michael donor, and wherein said solvent comprises 40% or more by weight, based on the weight of said solvent, one or more multi-functional Michael donor.

  14. Sound Solutions

    ERIC Educational Resources Information Center

    Starkman, Neal

    2007-01-01

    Poor classroom acoustics are impairing students' hearing and their ability to learn. However, technology has come up with a solution: tools that focus voices in a way that minimizes intrusive ambient noise and gets to the intended receiver--not merely amplifying the sound, but also clarifying and directing it. One provider of classroom audio…

  15. Dismantling techniques

    SciTech Connect

    Wiese, E.

    1998-03-13

    Most of the dismantling techniques used in a Decontamination and Dismantlement (D and D) project are taken from conventional demolition practices. Some modifications to the techniques are made to limit exposure to the workers or to lessen the spread of contamination to the work area. When working on a D and D project, it is best to keep the dismantling techniques and tools as simple as possible. The workers will be more efficient and safer using techniques that are familiar to them. Prior experience with the technique or use of mock-ups is the best way to keep workers safe and to keep the project on schedule.

  16. Compatible solutes

    PubMed Central

    Hill, Colin

    2010-01-01

    Recently we reported a role for compatible solute uptake in mediating bile tolerance and increased gastrointestinal persistence in the foodborne pathogen Listeria monocytogenes.1 Herein, we review the evolution in our understanding of how these low molecular weight molecules contribute to growth and survival of the pathogen both inside and outside the body, and how this stress survival mechanism may ultimately be used to target and kill the pathogen. PMID:21326913

  17. Analysis of earth rotation solution from Starlette

    NASA Technical Reports Server (NTRS)

    Schutz, B. E.; Cheng, M. K.; Shum, C. K.; Eanes, R. J.; Tapley, B. D.

    1989-01-01

    Earth rotation parameter (ERP) solutions were derived from the Starlette orbit analysis during the Main MERIT Campaign, using a technique of a consider-covariance analysis to assess the effects of errors on the polar motion solutions. The polar motion solution was then improved through the simultaneous adjustment of some dynamical parameters representing identified dominant perturbing sources (such as the geopotential and ocean-tide coefficients) on the polar motion solutions. Finally, an improved ERP solution was derived using the gravity field model, PTCF1, described by Tapley et al. (1986). The accuracy of the Starlette ERP solution was assessed by a comparison with the LAGEOS-derived ERP solutions.

  18. Emerging optical nanoscopy techniques

    PubMed Central

    Montgomery, Paul C; Leong-Hoi, Audrey

    2015-01-01

    To face the challenges of modern health care, new imaging techniques with subcellular resolution or detection over wide fields are required. Far field optical nanoscopy presents many new solutions, providing high resolution or detection at high speed. We present a new classification scheme to help appreciate the growing number of optical nanoscopy techniques. We underline an important distinction between superresolution techniques that provide improved resolving power and nanodetection techniques for characterizing unresolved nanostructures. Some of the emerging techniques within these two categories are highlighted with applications in biophysics and medicine. Recent techniques employing wider angle imaging by digital holography and scattering lens microscopy allow superresolution to be achieved for subcellular and even in vivo, imaging without labeling. Nanodetection techniques are divided into four subcategories using contrast, phase, deconvolution, and nanomarkers. Contrast enhancement is illustrated by means of a polarized light-based technique and with strobed phase-contrast microscopy to reveal nanostructures. Very high sensitivity phase measurement using interference microscopy is shown to provide nanometric surface roughness measurement or to reveal internal nanometric structures. Finally, the use of nanomarkers is illustrated with stochastic fluorescence microscopy for mapping intracellular structures. We also present some of the future perspectives of optical nanoscopy. PMID:26491270

  19. Numerical grid generation techniques. [conference

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The state of the art in topology and flow geometry is presented. Solution techniques for partial differential equations are reviewed and included developments in coordinate transformations, conformal mapping, and invariant imbeddings. Applications of these techniques in fluid mechanics, flow geometry, boundary value problems, and fluidics are presented.

  20. Solution Leaching

    NASA Astrophysics Data System (ADS)

    Chun, Tiejun; Zhu, Deqing; Pan, Jian; He, Zhen

    2014-06-01

    Recovery of alumina from magnetic separation tailings of red mud has been investigated by Na2CO3 solution leaching. X-ray diffraction (XRD) results show that most of the alumina is present as 12CaO·7Al2O3 and CaO·Al2O3 in the magnetic separation tailings. The shrinking core model was employed to describe the leaching kinetics. The results show that the calculated activation energy of 8.31 kJ/mol is characteristic for an internal diffusion-controlled process. The kinetic equation can be used to describe the leaching process. The effects of Na2CO3 concentration, liquid-to-solid ratio, and particle size on recovery of Al2O3 were examined.

  1. Numerical Techniques in Acoustics

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J. (Compiler)

    1985-01-01

    This is the compilation of abstracts of the Numerical Techniques in Acoustics Forum held at the ASME's Winter Annual Meeting. This forum was for informal presentation and information exchange of ongoing acoustic work in finite elements, finite difference, boundary elements and other numerical approaches. As part of this forum, it was intended to allow the participants time to raise questions on unresolved problems and to generate discussions on possible approaches and methods of solution.

  2. Helping Families Search for Solutions: Working with Adolescents

    ERIC Educational Resources Information Center

    Paylo, Matthew J.

    2005-01-01

    In this column, the author focuses on the ways that family counselors can use solution-based therapies (solution-oriented and solution-focused) to work with families with adolescents in individual and/or family therapy. The theoretical foundation for solution-based therapies suggests techniques that help families focus on solutions and not remain…

  3. Multigrid solution of internal flows using unstructured solution adaptive meshes

    NASA Astrophysics Data System (ADS)

    Smith, Wayne A.; Blake, Kenneth R.

    1992-11-01

    This is the final report of the NASA Lewis SBIR Phase 2 Contract Number NAS3-25785, Multigrid Solution of Internal Flows Using Unstructured Solution Adaptive Meshes. The objective of this project, as described in the Statement of Work, is to develop and deliver to NASA a general three-dimensional Navier-Stokes code using unstructured solution-adaptive meshes for accuracy and multigrid techniques for convergence acceleration. The code will primarily be applied, but not necessarily limited, to high speed internal flows in turbomachinery.

  4. Stapedectomy technique.

    PubMed

    House, J W

    1993-06-01

    This article reviews the evolution of the author's stapedectomy technique from total footplate removal with single loop wire prosthesis and Gelfoam seal to small fenestra stapedectomy with platinum ribbon piston prosthesis and blood seal. The author concludes that the microdrill is effective, safe, and cost effective for performing this procedure. Since using this technique, the author has had no cases of sensorineural hearing loss and few complaints of dizziness or vertigo. PMID:8341570

  5. Spatial Techniques

    NASA Astrophysics Data System (ADS)

    Jabeur, Nafaa; Sahli, Nabil

    The environment, including the Earth and the immense space, is recognized to be the main source of useful information for human beings. During several decades, the acquisition of data from this environment was constrained by tools and techniques with limited capabilities. However, thanks to continuous technological advances,spatial data are available in huge quantities for different applications. The technological advances have been achieved in terms of hardware and software as well. They are allowing for better accuracy and availability, which in turn improves the quality and quantity of useful knowledge that can be extracted from the environment. They have been applied to geography, resulting in geospatial techniques. Applied to both science and technology, geospatial techniques resulted in areas of expertise, such as land surveying, cartography, navigation, remote sensing, Geographic Infor-mation Systems (GISs), and Global Positioning Systems (GPSs). They had evolved quickly with advances in computing, satellite technology and a growing demand to understand our global environment. In this chapter, we will discuss three important techniques that are widely used in spatial data acquisition and analysis: GPS and remote sensing techniques that are used to collect spatial data and a GIS that is used to store, manipulate, analyze, and visualize spatial data. Later in this book, we will discuss the techniques that are currently available for spatial knowledge discovery.

  6. Naturally selecting solutions

    PubMed Central

    Manning, Timmy; Sleator, Roy D; Walsh, Paul

    2013-01-01

    For decades, computer scientists have looked to nature for biologically inspired solutions to computational problems; ranging from robotic control to scheduling optimization. Paradoxically, as we move deeper into the post-genomics era, the reverse is occurring, as biologists and bioinformaticians look to computational techniques, to solve a variety of biological problems. One of the most common biologically inspired techniques are genetic algorithms (GAs), which take the Darwinian concept of natural selection as the driving force behind systems for solving real world problems, including those in the bioinformatics domain. Herein, we provide an overview of genetic algorithms and survey some of the most recent applications of this approach to bioinformatics based problems. PMID:23222169

  7. Life's Solution

    NASA Astrophysics Data System (ADS)

    Morris, Simon Conway

    2003-09-01

    Life's Solution builds a persuasive case for the predictability of evolutionary outcomes. The case rests on a remarkable compilation of examples of convergent evolution, in which two or more lineages have independently evolved similar structures and functions. The examples range from the aerodynamics of hovering moths and hummingbirds to the use of silk by spiders and some insects to capture prey. Going against the grain of Darwinian orthodoxy, this book is a must read for anyone grappling with the meaning of evolution and our place in the Universe. Simon Conway Morris is the Ad Hominen Professor in the Earth Science Department at the University of Cambridge and a Fellow of St. John's College and the Royal Society. His research focuses on the study of constraints on evolution, and the historical processes that lead to the emergence of complexity, especially with respect to the construction of the major animal body parts in the Cambrian explosion. Previous books include The Crucible of Creation (Getty Center for Education in the Arts, 1999) and co-author of Solnhofen (Cambridge, 1990). Hb ISBN (2003) 0-521-82704-3

  8. Life's Solution

    NASA Astrophysics Data System (ADS)

    Morris, Simon Conway

    2004-11-01

    Life's Solution builds a persuasive case for the predictability of evolutionary outcomes. The case rests on a remarkable compilation of examples of convergent evolution, in which two or more lineages have independently evolved similar structures and functions. The examples range from the aerodynamics of hovering moths and hummingbirds to the use of silk by spiders and some insects to capture prey. Going against the grain of Darwinian orthodoxy, this book is a must read for anyone grappling with the meaning of evolution and our place in the Universe. Simon Conway Morris is the Ad Hominen Professor in the Earth Science Department at the University of Cambridge and a Fellow of St. John's College and the Royal Society. His research focuses on the study of constraints on evolution, and the historical processes that lead to the emergence of complexity, especially with respect to the construction of the major animal body parts in the Cambrian explosion. Previous books include The Crucible of Creation (Getty Center for Education in the Arts, 1999) and co-author of Solnhofen (Cambridge, 1990). Hb ISBN (2003) 0-521-82704-3

  9. Alloy solution hardening with solute pairs

    DOEpatents

    Mitchell, John W.

    1976-08-24

    Solution hardened alloys are formed by using at least two solutes which form associated solute pairs in the solvent metal lattice. Copper containing equal atomic percentages of aluminum and palladium is an example.

  10. Decomposition techniques

    USGS Publications Warehouse

    Chao, T.T.; Sanzolone, R.F.

    1992-01-01

    Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.